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PubMedDate not supplied

Topical antimicrobial therapy in the prevention of early childhood caries.

PURPOSE: Early childhood caries (ECC) is microbiologically characterized by heavy infection of mutans streptococci (ms) on dental surfaces. Accordingly, it is reasonable to speculate that suppression of dental ms levels would decrease risk for ECC. On this basis, randomized double blind, placebo controlled pilot study was performed to test this concept. METHODS: The study population consisted of 31 subjects (age: 12 to 19 mos; sex: 18F/13M) who were clients of a Women, Infants, and Children (WIC) clinic in Puerto Rico. Inclusion criteria included: (1) unremarkable medical history; (2) presence of 4 maxillary primary incisors (PMI) with no visible defects; (3) clinically caries free; (4) use of a nursing bottle at naptime and/or bedtime which contained a cariogenic substrate; (5) two consecutive ms positive cultures (utilizing Mitis-Salivarius-Bacitracin (MSB) agar) from pooled PMI plaque. The subjects were randomized into 2 groups. The 15 subjects in the experimental group and the 16 subjects in the control group were evaluated every 2 months during the study period. At each evaluation, the subjects had 10% povidone iodine (experimental group) or placebo (control group) applied to their dentition. The placebo was commercial instant tea (without lemon or sweetener) and deionized water. Treatment failure was defined as the appearance of a white spot lesion(s) on any of the PMI during the study period. RESULTS: The mean duration of observation to treatment failure was 155 days; the mean duration of observation for treatment success was 217 days. Five of the 16 control subjects and 0 of the 15 experimental subjects experienced treatment failure (Fisher's exact test: P = 0.04). The Kaplan-Meier estimate for incidence of treatment failure in the placebo group was 48% over 357 days (P = 0.02). CONCLUSION: These observations suggest that topical antimicrobial therapy reduces risk for the development of ECC in high-risk children.

Anti-Infective Agents, Local↗

PubMed2001

Schizophrenic patients' normative needs for community-based psychiatric care: an evaluative study throughout the year following hospital release in the Dresden region.

BACKGROUND: The present study is part of a public health research project that evaluates restructured psychiatric community care for chronic patients in Saxony after the German reunification. It focuses on the analysis of the individual (expert-based) normative needs for mental health care of chronic schizophrenic patients in the Dresden region. METHOD: A cohort of ICD-10 chronic schizophrenic patients (n = 115) was examined at 1, 6 and 12 months after hospital release using the Needs for Care Assessment. RESULTS: Schizophrenics' normative needs for care in the clinical sector are dominated by positive and negative symptoms, psychopharmacological side effects and psychosocial distress. In the social realm, problems dealing with the management of household affairs, recreational activities, household chores, occupation and communication skills are the most frequent areas of need. In the Dresden region, considerable deficits apparently persist in the subsections "recreational activities" and "occupational and communication skills", which can be ascribed to the lack of appropriate institutions of care in the area. Schizophrenic patients' normative needs for care cannot be determined simply on the basis of a few, quickly identifiable markers. Individualized analysis is needed that incorporates variables pertaining to psychopathology, subjective coping, social competence, and the course of the disorder. The development of the needs for care over the period of 1 year can be predicted by trends in the social realm that are already visible within the first months. CONCLUSIONS: Community-based care offers available for schizophrenic patients in the studied region are by no means generally insufficient. Identified deficits in focal fields of social skills and rehabilitation must be minimized to meet international standards. This is of special importance because social impairments/disabilities predominate over the entire spectrum of schizophrenics' normative needs for psychiatric care.

Adult↗

PubMed2006

Correction of patient positioning errors based on in-line cone beam CTs: clinical implementation and first experiences.

BACKGROUND: The purpose of the study was the clinical implementation of a kV cone beam CT (CBCT) for setup correction in radiotherapy. PATIENTS AND METHODS: For evaluation of the setup correction workflow, six tumor patients (lung cancer, sacral chordoma, head-and-neck and paraspinal tumor, and two prostate cancer patients) were selected. All patients were treated with fractionated stereotactic radiotherapy, five of them with intensity modulated radiotherapy (IMRT). For patient fixation, a scotch cast body frame or a vacuum pillow, each in combination with a scotch cast head mask, were used. The imaging equipment, consisting of an x-ray tube and a flat panel imager (FPI), was attached to a Siemens linear accelerator according to the in-line approach, i.e. with the imaging beam mounted opposite to the treatment beam sharing the same isocenter. For dose delivery, the treatment beam has to traverse the FPI which is mounted in the accessory tray below the multi-leaf collimator. For each patient, a predefined number of imaging projections over a range of at least 200 degrees were acquired. The fast reconstruction of the 3D-CBCT dataset was done with an implementation of the Feldkamp-David-Kress (FDK) algorithm. For the registration of the treatment planning CT with the acquired CBCT, an automatic mutual information matcher and manual matching was used. RESULTS AND DISCUSSION: Bony landmarks were easily detected and the table shifts for correction of setup deviations could be automatically calculated in all cases. The image quality was sufficient for a visual comparison of the desired target point with the isocenter visible on the CBCT. Soft tissue contrast was problematic for the prostate of an obese patient, but good in the lung tumor case. The detected maximum setup deviation was 3 mm for patients fixated with the body frame, and 6 mm for patients positioned in the vacuum pillow. Using an action level of 2 mm translational error, a target point correction was carried out in 4 cases. The additional workload of the described workflow compared to a normal treatment fraction led to an extra time of about 10-12 minutes, which can be further reduced by streamlining the different steps. CONCLUSION: The cone beam CT attached to a LINAC allows the acquisition of a CT scan of the patient in treatment position directly before treatment. Its image quality is sufficient for determining target point correction vectors. With the presented workflow, a target point correction within a clinically reasonable time frame is possible. This increases the treatment precision, and potentially the complex patient fixation techniques will become dispensable.

Automation↗

PubMed2002

[Radiology and measurement in adolescent slipped capital femoral epiphysis].

Two X-rays taken in two planes perpendicular to each other secure the early diagnosis of adolescent slipped capital femoral epiphysis (SCFE). In imminent SCFE, two radiographic features are considered the most important signs: the broadening and the irregular demarcation of the upper femoral epiphyseal plate. In the beginning of SCFE, the process of dislocation is much better visible in the second radiographic plane (the lateral tangent of the femoral neck builds a smaller secant of the lateral femoral head). In chronic SCFE, the aforementioned radiographic signs including the epiphyseal dislocation are more marked. An additional feature can be various deformities of the femoral neck and duplicate contours of the medial demarcation of the femoral neck. In acute SCFE, there is a complete disruption of continuity between the metaphysis and epiphysis. Beside the marked gap in the epiphyseal plate, there is a severe dislocation between the femoral neck and the epiphysis. There are also partly patchy, partly cystic changes in the metaphyseal part of the femoral neck. The so-called acute on chronic slip, a sudden slip of the upper epiphysis after prolonged chronic slipping, is considered a specific case of SCFE. The long-term result of treated as well as untreated SCFE can be the gradual increase of coxarthrosis, which is typically more marked in the medial direction of the joint. The direction and the degree of the epiphyseal slip play an important role in the development of "epiphyseal" coxarthrosis. The planning of corrective operations as well as the quantitative evaluation of the prearthrotic deformity require the conversion of angles of dislocation that are projected on X-rays into anatomically correct angles. This conversion is done with tables that were created with the aid of computers and requires that the positioning of the femur for taking the X-rays is always done under standardized conditions.Mostly, in minor dislocations in the usual direction (medially and dorsally), the difference between the projected and the real angles is relatively small. Therefore, in these cases of SCFE it might not be necessary for practical and operative needs to convert these angles into real angles. However, this simplification is only then acceptable if the prescribed positioning of the femur for taking the X-rays is strictly adhered to so that additional errors of projection are excluded.

Adolescent↗

PubMed1995

Mammographic features and breast cancer risk: effects with time, age, and menopause status.

BACKGROUND: Mammographic images from women with a high proportion of epithelial and stromal breast tissues are described as showing high-density parenchymal patterns. Most past studies that noted an increase in breast cancer risk associated with mammographic parenchymal patterns showing high density either 1) lacked information on other breast cancer risk factors, 2) were too small, or 3) included insufficient follow-up time to adequately resolve persisting doubts whether mammographic features are "independent" measures of breast cancer risk and not a detection artifact. PURPOSE: The purpose of this study was twofold: 1) to evaluate the associations between mammographic features and other breast cancer risk factors and 2) to assess effects of mammographic features on breast cancer risk by time, age, and menopause status. METHODS: To address these questions, we analyzed detailed information from a large, nested case-control study with 16 years of follow-up. This study used information from both screening and follow-up phases of the Breast Cancer Detection Demonstration Project, a nationwide program that offered annual breast cancer screening for more than 280,000 women from 1973 to 1980. Mammographic features were assessed from the base-line screening mammographic examination for 1880 incident case subjects and 2152 control subjects. Control subjects were randomly selected from women of the same age and race as each case subject. Control subjects attended the same screening center as the case subject and were free of breast cancer at the case subject's date of diagnosis. Odds ratios (ORs) with 95% confidence intervals (CIs) provided estimates of the relative risk of breast cancer. RESULTS: Mammographic features were associated with known breast cancer risk factors. However, the high-density parenchymal pattern effects were independent of family history, age at first birth, alcohol consumption, and benign breast disease. The increase risk for women with Wolfe's two high-density parenchymal patterns, P2 (OR = 3.2; 95% CI = 2.5-4.0) and Dy (OR = 2.9; 95% CI = 2.2-3.9), was explained primarily by measured percent of the breast with dense mammographic appearance. Compared with women with no visible breast density, women who had a breast density of 75% or greater had an almost fivefold increased risk of breast cancer (95% CI = 3.6-7.1). These effects persisted for 10 or more years and were noted for both premenopausal and postmenopausal women of all ages. CONCLUSIONS: Of the breast cancer risk factors assessed in the participants, high-density mammographic parenchymal patterns, as measured by the proportion of breast area composed of epithelial and stromal tissue, had the greatest impact on breast cancer risk. Of the breast cancers in this study, 28% were attributable to having 50% or greater breast density.

Age Factors↗

PubMed1994

Diagnosis of choledocholithiasis: value of MR cholangiography.

OBJECTIVE: T2-weighted fast spin-echo MR imaging (MR cholangiography) of the right upper quadrant of the abdomen depicts the biliary tree in considerable detail. We studied the value of this procedure for detecting stones in the common bile duct in a series of patients with proved calculi. MATERIALS AND METHODS: MR images of 10 consecutive patients with stones in the common bile duct were retrospectively reviewed. The diagnosis of choledocholithiasis was proved by stone extraction in all cases. Axial, coronal, and oblique images were obtained by using heavily T2-weighted fast spin-echo sequences, and the images were processed by using a maximum-intensity-projection (MIP) algorithm and a commercially available multiplanar reformatting software. Two reviewers who were not blinded to the diagnosis analyzed hard copy images and reformatted images at the MR console. The rate of stone detection was evaluated for each acquisition plane. The mean stone/bile signal-intensity ratio and the number and size of stones were recorded. RESULTS: In all patients, the entire length of the extrahepatic bile ducts was visualized, and the diagnosis of choledocholithiasis could be made on the basis of findings on MR images. Eight stones, including two that were impacted in the ampulla, were located in the distal part of the common bile duct. On the hard copy films, the stones were visible in eight of 10 coronal images, six of 10 axial images, and four of 10 oblique images. On the three-dimensional (3D) MIP reconstructions, the stones were seen in five of the coronal sets and in six of the axial sets. The best results were obtained when the multiplanar reconstruction software was used: nine of the 10 coronal sets and eight of the 10 axial sets showed stones in the bile ducts. By use of a combination of 3D MIP and multiplanar reconstruction, choledocholithiasis was detected in all 10 patients. The mean signal intensity of the stones was 58 (range, 18-87). The mean stone/bile signal-intensity ratio was 0.15 (range, 0.05-0.24). CONCLUSION: In this preliminary study, we showed that MR cholangiography, based on T2-weighted fast spin-echo sequences, could be an important imaging technique for patients with suspected bile duct obstruction and equivocal sonography and/or CT results. However, a large prospective clinical trial is needed to confirm these results.

Cholangiography↗

PubMed1974

Status of women microbiologists.

The general picture that emerges from this study is that the woman microbiologist, upon entering the professional job market, faces (i) slower advancement; (ii) restricted extramural recognition; and (iii) fewer positions of a supervisory or administrative nature, when compared to men. Most striking is the salary differential, which increases with increasing educational level, with increasing rank, and with increasing seniority. From the beginning of her professional training, the woman microbiologist feels handicapped by lack of encouragement and proper role models. She generally receives little advice regarding her professional future and rarely feels pushed to take the most challenging position. Should she be married, she feels that her mobility is severely restricted. Even though the subjective nature of these feelings may be interpreted as projections of failure, subtle inducements for women to stay at lower levels may well exist, in addition to more objective measurements, such as lower salary levels and slower professional advancement. Despite these handicaps, professional women continue to work. As a group, they work for the same reasons that men do, they work as long and as hard as men do, and they remain at their positions as long as men do. Women and men rate themselves equally as to job performance, degree of independence, and publication rate. On the basis of this study, it should not be surprising that women professionals are less visible than men and that only a small proportion of women become what is considered successful by the usual external criteria. If women were to receive continued encouragement, scientific contact, and professional recognition at each stage of their professional lives, they would undoubtedly become more visible. The lack of encouragement and selfconfidence leading to isolation, which then leads to lack of recognition, is a vicious circle that must be broken for the woman professional. This can be done most easily for the beginning student. For older women, there must be increased placement in positions of responsibility and visibility. Protective practices that discourage women from entering arenas of competition can only be viewed as discrimination on the basis of sex, since women professionals are rarely given the choice between being protected and being independent. Unexpectedly, this study illustrates the lower status of another group of individuals who are considered deviants from the expected roles of the established society-single men with doctorates, who were found in the positions predominately filled by women. In conclusion, this study of a select group of scientists probably has general applicability to all women professionals in their roles vis-à-vis men. Examination and documentation of discriminatory practices based on sex points to the areas in which women must direct their demands for equality.

Economics↗

PubMed2004

Integrated radiotherapy imaging system (IRIS): design considerations of tumour tracking with linac gantry-mounted diagnostic x-ray systems with flat-panel detectors.

The design of an integrated radiotherapy imaging system (IRIS), consisting of gantry mounted diagnostic (kV) x-ray tubes and fast read-out flat-panel amorphous-silicon detectors, has been studied. The system is meant to be capable of three main functions: radiographs for three-dimensional (3D) patient set-up, cone-beam CT and real-time tumour/marker tracking. The goal of the current study is to determine whether one source/panel pair is sufficient for real-time tumour/marker tracking and, if two are needed, the optimal position of each relative to other components and the isocentre. A single gantry-mounted source/imager pair is certainly capable of the first two of the three functions listed above and may also be useful for the third, if combined with prior knowledge of the target's trajectory. This would be necessary because only motion in two dimensions is visible with a single imager/source system. However, with previously collected information about the trajectory, the third coordinate may be derived from the other two with sufficient accuracy to facilitate tracking. This deduction of the third coordinate can only be made if the 3D tumour/marker trajectory is consistent from fraction to fraction. The feasibility of tumour tracking with one source/imager pair has been theoretically examined here using measured lung marker trajectory data for seven patients from multiple treatment fractions. The patients' selection criteria include minimum mean amplitudes of the tumour motions greater than 1 cm peak-to-peak. The marker trajectory for each patient was modelled using the first fraction data. Then for the rest of the data, marker positions were derived from the imager projections at various gantry angles and compared with the measured tumour positions. Our results show that, due to the three dimensionality and irregular trajectory characteristics of tumour motion, on a fraction-to-fraction basis, a 'monoscopic' system (single source/imager) is inadequate for consistent real-time tumour tracking, even with prior knowledge. We found that, among the seven patients studied with peak-to-peak marker motion greater than 1 cm, five cases have mean localization errors greater than 2 mm and two have mean errors greater than 3 mm. Because of this uncertainty associated with a monoscopic system, two source/imager pairs are necessary for robust 3D target localization. Dual orthogonal x-ray source/imager pairs mounted on the linac gantry are chosen for the IRIS. We further studied the placement of the x-ray sources/panel based on the geometric specifications of the Varian 21EX Clinac. The best configuration minimizes the localization error while maintaining a large field of view and avoiding collisions with the floor/ceiling or couch.

Humans↗

PubMed1998

Baumkuchen map analysis to detect postural cerebral hypoperfusion with upright 99Tcm-HMPAO brain SPET.

We have evaluated a polar cortical flow Baumkuchen map (BK map), constructed from projection data by inwardly layering cortical flow stripes from the base to the apex, to detect postural cerebral hypoperfusion using 99Tcm-HMPAO brain SPET. A circular cortical perfusion outline was constructed from sinogram data at a 20% threshold; a ring was then formed by constructing an inner line with a radius equal to half that of the outer line. This ring on the transaxial image was superimposed onto the cortical image, then divided into 60 portions at 6 degrees intervals from the centre. The maximal number of counts per pixel within each sector was determined, translated into polar coordinate profiles and displayed as a polar map. We studied 11 patients with unilateral stenosis of the internal carotid artery or middle cerebral artery (MCA) and 7 patients without stenosis, using upright and supine (rest) 99Tcm-HMPAO brain SPET Cerebral perfusion was visibly altered on the BK maps of all 11 patients with arterial stenosis and on the transaxial images of 8 of them. A semi-quantitative analysis of the BK maps using a ratio of the counts in the regions of interest over the right and left MCA areas, showed that the mean of the ratios was significantly lower in the upright images than in the upright + rest and rest images (P = 0.0044 and 0.0033, respectively). Although the difference in the means of the ratios between the upright and upright + rest images was significant for both the BK map and transaxial image data (P = 0.0044 and 0.0051, respectively), the BK map was accurate in detecting changes in perfusion in the upright position. We conclude that BK map analysis is useful for detecting changes in patients examined using upright brain SPET.

Adult↗

PubMed1995

The illuminated high contrast macular grid: a pilot study.

BACKGROUND: Analysis of visual disturbances in the central 10 degrees provides valuable data for the low vision clinician. Amsler grid testing in the visually impaired can be poorly visible and it can be difficult to transcribe results. Automated perimeters will accurately map retinal defects, but the equipment is expensive and this technique is time consuming. An Amsler grid was modified using principles of luminance and contrast to improve its accuracy, and its efficacy was compared to an automated perimeter. METHODS: Eighteen visually impaired patients (28 eyes) were prospectively evaluated at the Emory Low Vision Laboratory. Each patient had three central threshold visual field tests: automated perimetry (Humphrey model 690), conventional Amsler Grid, and Illuminated High Contrast Macular Grid (IHCMG). The Humphrey central 10-2 threshold automated visual field examination was performed to map the patient's retinal function. RESULTS: The Humphrey analysis identified (mean +/- one standard deviation) 2.4 +/- 1.4 defects per patient with an average percent defect area of 33.4 +/- 14.8 degrees. The IHCMG technique was not significantly different from the Humphrey technique for identifying the number of defects (2.25 +/- 1.5) (p > 0.05) or the percent defect area (26 degrees +/- 20 degrees) (p > 0.05). The conventional Amsler grid technique significantly under-evaluated the retinal defects compared to the Humphrey analysis of the number of defects (p < 0.01) and percent area of defects (p > 0.001). CONCLUSIONS: The IHCMG technique can be used as a simple, rapid and accurate analysis of the central 10 degrees visual field in the low vision patient.

Aged↗

PubMedDate not supplied

A portrait of Asians and Pacific Islanders in the United States.

Asians and Pacific Islanders (API) have an increasingly visible presence in the United States. This diverse population--encompassing persons with ancestry from East and Southeast Asia, the Indian subcontinent, and the Pacific islands--has grown at a faster rate than any other major racial or ethnic group. In 1996 Asian Americans numbered approximately 9.7 million (up from 3.8 million in 1980), nearly 4 percent of the U.S. population. The Census Bureau projects that this population group will reach 34.4 million by 2050, representing roughly 9 percent of all Americans. While immigration has fueled much of this growth, Asians' young age structure also will help boost their numbers in the next century. Fifty-six percent of Asian Americans live in three states--California, New York and Hawaii. Asian Americans comprise very small proportions of the populations of most other states. About 77 percent of the 2.8 million API households in 1996 were families, compared with 69 percent of white households. Roughly one in six Asian American households has five or more persons, compared with one in 12 white households. Educationally, Asians tend to be high achievers--42 percent of all API adults have at least a bachelor's degree, compared with 26 percent of while adults. Two-thirds of Asian Americans participated in the civilian labor force in 1996. Among employed Asians, one-third held managerial and professional jobs. Both proportions were roughly the same as for whites. Although the median income for API households was 9 percent higher than for white households in 1995, this difference is largely due to Asian households having more workers contributing to the household income. Despite these apparent measures of success, the poverty rates for Asian American families and individuals are nearly twice as high as those for whites.

Adult↗

PubMed2006

Multiview-based computer-aided detection scheme for breast masses.

In this study, we developed and tested a new multiview-based computer-aided detection (CAD) scheme that aims to maintain the same case-based sensitivity level as a single-image-based scheme while substantially increasing the number of masses being detected on both ipsilateral views. An image database of 450 four-view examinations (1800 images) was assembled. In this database, 250 cases depicted malignant masses, of which 236 masses were visible on both views and 14 masses were visible only on one view. First, we detected suspected mass regions depicted on each image in the database using a single-image-based CAD. For each identified region (with detection score > or = 0.55), we then identified a matching strip of interest on the ipsilateral view based on the projected distance to the nipple along the centerline. By lowering CAD operating threshold inside the matching strip, we searched for a region located inside the strip and paired it with the original region. A multifeature-based artificial neural network scored the likelihood of the paired "matched" regions representing true-positive masses. All single (unmatched) regions except for those either with very high detection scores (> or = 0.85) or those located near the chest wall that cannot be matched on the other view were discarded. The original single-image-based CAD scheme detected 186 masses (74.4% case-based sensitivity) and 593 false-positive regions. Of the 186 identified masses, 91 were detected on two views (48.9%) and 95 were detected only on one view (51.1%). Of the false-positive detections, 54 were paired on the ipsilateral view inside the corresponding matching strips and the remaining 485 were not, which represented 539 case-based false-positive detections (0.3 per image). Applying the multiview-based CAD scheme, the same case-based sensitivity was maintained while cueing 169 of 186 masses (90.9%) on both views and at the same time reducing the case-based false-positive detection rate by 23.7% (from 539 to 411). The study demonstrated that the new multiview-based CAD scheme could substantially increase the number of masses being cued on two ipsilateral views while reducing the case-based false-positive detection rate.

Algorithms↗

PubMed2005

Time-domain scanning optical mammography: II. Optical properties and tissue parameters of 87 carcinomas.

Within a clinical trial on scanning time-domain optical mammography reported on in a companion publication (part I), craniocaudal and mediolateral projection optical mammograms were recorded from 154 patients, suspected of having breast cancer. Here we report on in vivo optical properties of the subset of 87 histologically validated carcinomas which were visible in optical mammograms recorded at two or three near-infrared wavelengths. Tumour absorption and reduced scattering coefficients were derived from distributions of times of flight of photons recorded at the tumour site employing the model of diffraction of photon density waves by a spherical inhomogeneity, located in an otherwise homogeneous tissue slab. Effective tumour radii, taken from pathology, and tumour location along the compression direction, deduced from off-axis optical scans of the tumour region, were included in the analysis as prior knowledge, if available. On average, tumour absorption coefficients exceeded those of surrounding healthy breast tissue by a factor of about 2.5 (670 nm), whereas tumour reduced scattering coefficients were larger by about 20% (670 nm). From absorption coefficients at 670 nm and 785 nm total haemoglobin concentration and blood oxygen saturation were deduced for tumours and surrounding healthy breast tissue. Apart from a few outliers total haemoglobin concentration was observed to be systematically larger in tumours compared to healthy breast tissue. In contrast, blood oxygen saturation was found to be a poor discriminator for tumours and healthy breast tissue; both median values of blood oxygen saturation are the same within their statistical uncertainties. However, the ratio of total haemoglobin concentration over blood oxygen saturation further improves discrimination between tumours and healthy breast tissue. For 29 tumours detected in optical mammograms recorded at three wavelengths (670 nm, 785 nm, 843 nm or 884 nm), scatter power was derived from transport scattering coefficients. Scatter power of tumours tends to be larger than that of surrounding healthy breast tissue, yet the 95% confidence intervals of both medians overlap.

Breast Neoplasms↗

PubMed2003

The placebo needle, is it a valid and convincing placebo for use in acupuncture trials? A randomised, single-blind, cross-over pilot trial.

The issue of what constitutes an effective and realistic acupuncture placebo control has been a continuing problem for acupuncture research. In order to provide an effective placebo, the control procedure must be convincing, visible and should mimic, in all respects, apart from a physiological effect, the real active treatment. The 'Streitberger' needle might fulfil these criteria and this paper reports on a validation study. This was a single-blind, randomised, cross-over pilot study. Patients were drawn from the orthopaedic hip and knee, joint replacement waiting list. Intervention consisted of either 2 weeks of treatment with real acupuncture followed by 2 weeks on placebo, or vice versa. The prime outcome was a needle sensation questionnaire and there was a range of secondary outcomes. Thirty-seven patients were randomised and completed treatment. Groups were well balanced at baseline. No significant differences between groups or needle types were found for any of the sensations measured. Most patients were unable to discriminate between the needles by penetration; however, nearly 40% were able to detect a difference in treatment type between needles. No major differences in outcome between real and placebo needling could be found. The fact that nearly 40% of subjects did not find that the two interventions were similar, however, raises some concerns with regard to the wholesale adoption of this instrument as a standard acupuncture placebo. Further work on inter-tester reliability and standardisation of technique is highly recommended before we can be confident about using this needle in further studies.

Acupuncture Therapy↗

PubMed2004

Tumour cell displacement after 14G breast biopsy.

INTRODUCTION: Seeding of biopsy needle tracks with viable malignant cells was an initial concern with all diagnostic breast needle procedures, including 14G automated needle biopsy. In an attempt to further evaluate this phenomenon, we have addressed the following questions: (1) are the tracks left by the needle biopsy procedure detectable in the surgical excision specimen? (2) Are displaced tumour cells visible along the needle tracks? (3) Is it possible to identify and excise the entire needle track for thorough histopathologic evaluation? METHODS: Surgical biopsy specimens of patients previously diagnosed with cancer on stereotactic 14G-needle biopsy were studied to find needle tracks. These are characterised by hemosiderin, scar tissue, foreign body giant cell reaction, fat necrosis, or organizing haemorrhage. Occurrence of displaced tumour cells or groups of cells along the tracks was registered. RESULTS: Needle tracks were found in 22/64 excision specimens of patients who underwent 14G-needle biopsy and surgery on the same day. Tumour-cell displacement along the needle track was seen in 11/22 cases (50%). In a prospective study, an attempt was made to excise the entire needle track in 13 consecutive cancer cases after 14G biopsy. Median time interval between core biopsy and first surgical excision was 21 days (range 7-35). Needle tracks could be visualised in 11/13 cases; displaced cells were seen in seven. CONCLUSION: Needle tracks can be found in the excision specimens of patients who previously underwent 14G biopsy, and displaced tumour cells can be recognised. Excision of the entire needle track is neither feasible, nor advisable as a routine measure, since radiotherapy is advised for both in situ and invasive carcinoma after conservative surgery.

Biopsy, Needle↗

PubMed2006

Can endoscopic ultrasonography-guided fine-needle aspiration predict response to chemoradiation in non-small cell lung cancer? A pilot study.

BACKGROUND: Accurate prediction of pathologic response to chemoradiation (CHEMO-XRT) has a significant impact on the treatment of patients with non-small cell lung cancer (NSCLC) and mediastinal lymph node (LN) metastasis (N2 disease). OBJECTIVE: This pilot study evaluates the ability of EUS-FNA to predict pathologic response in LN following CHEMO-XRT in NSCLC patients with N2 disease. PATIENTS AND METHODS: Retrospective analysis of prospectively collected data on patients with NSCLC and biopsy-proven N2 disease who underwent restaging by EUS following CHEMO-XRT. At restaging, FNA was performed on the same LN, if present, or any other visible LN in the posterior mediastinum. Response to therapy (N0 disease) was defined by either absence of mediastinal LN or residual disease on FNA. Those staged N0 by EUS underwent tumor resection with complete LN dissection. RESULTS: Fourteen patients met the criteria for evaluation. Restaging by EUS suggested disease response in 7 patients and residual disease in 6; tissue yield was unsatisfactory in 1 patient. Eleven of 14 patients in whom mediastinal LN were seen at restaging by EUS underwent FNA: the aspirate was benign in 4, residual disease was found in 6, and an inadequate sample was obtained in 1 patient. In 3 patients no mediastinal LN were evident at EUS. Final diagnosis on the 7 patients in whom EUS suggested N0 disease was established at surgery: EUS was true negative in 6 and false negative in 1. Of the 6 patients with residual disease, 5 underwent palliative CHEMO-XRT and 1 underwent extended tumor resection. The patient in whom tissue sampling was inadequate was found to have residual disease at surgery. The diagnostic accuracy of EUS-FNA for predicting mediastinal response to preoperative CHEMO-XRT was 86%. CONCLUSIONS: EUS-FNA appears to qualify as an accurate, safe and minimally invasive diagnostic technique for restaging of mediastinal LN after CHEMO-XRT in NSCLC patients. Given this promising preliminary data, a prospective evaluation is justified.

Aged↗

PubMed1987

On the late invention of the stereoscope.

It was not until 1838, when Wheatstone published his account of the stereoscope, that stereoscopic depth perception entered into the body of binocular phenomena. It is argued that the stereoscope was not invented earlier because the phenomenon of stereopsis based on disparity had not been adequately described. This was the case despite the fact that there had been earlier descriptions of tasks that could be performed better with two eyes than with one; the perceptual deficits attendant upon the loss of one eye had been remarked upon; analyses of the projections to each eye were commonplace, and binocular disparities were accurately illustrated; moreover, binocular microscopes and telescopes had been made over a century earlier. Theories of binocular vision were generally confined to accounting for singleness of vision with two eyes, and the concepts employed to account for this were visible direction, corresponding retinal points, and union in the brain. The application of these concepts inhibited any consideration of disparities, other than for yielding diplopia. When perception of the third dimension was addressed by Berkeley at the beginning of the eighteenth century, it was in the context of monocular vision and binocular convergence. Thereafter visual direction became the province for binocular vision and it was analysed in terms of geometrical optics, whereas visual distance was examined in the context of learned associations between vision and touch. This artificial division was challenged initially with respect to visual direction and later with respect to stereopsis. An additional factor delaying the invention of the stereoscope was that experiments on binocular vision generally involved abnormal convergence on extended objects. Wheatstone's accidental observation of stereopsis was under artificial conditions in which disparity alone defined the binocular depth perceived. Once invented the stereoscope was enthusiastically embraced by students of vision. It is suggested that the ease with which retinal disparity could be manipulated in stereopairs has led to an exaggeration of its importance in space perception. "The appearances, which are by this simple instrument rendered so obvious, may be easily inferred from the established laws of perspective; for the same object in relief is, when viewed by a different eye, seen from the two points of sight at a distance from each other equal to the line joining the two eyes. Yet they seem to have escaped the attention of every philosopher and artist who has treated of the subjects of vision and perspective." (Wheatstone 1838, page 371).

Depth Perception↗

PubMed2002

Implementation, calibration and accuracy testing of an image-enhanced endoscopy system.

This paper presents a new method for image-guided surgery called image-enhanced endoscopy. Registered real and virtual endoscopic images (perspective volume renderings generated from the same view as the endoscope camera using a preoperative image) are displayed simultaneously; when combined with the ability to vary tissue transparency in the virtual images, this provides surgeons with the ability to see beyond visible surfaces and, thus, provides additional exposure during surgery. A mount with four photoreflective spheres is rigidly attached to the endoscope and its position and orientation is tracked using an optical position sensor. Generation of virtual images that are accurately registered to the real endoscopic images requires calibration of the tracked endoscope. The calibration process determines intrinsic parameters (that represent the projection of three-dimensional points onto the two-dimensional endoscope camera imaging plane) and extrinsic parameters (that represent the transformation from the coordinate system of the tracker mount attached to the endoscope to the coordinate system of the endoscope camera), and determines radial lens distortion. The calibration routine is fast, automatic, accurate and reliable, and is insensitive to rotational orientation of the endoscope. The routine automatically detects, localizes, and identifies dots in a video image snapshot of the calibration target grid and determines the calibration parameters from the sets of known physical coordinates and localized image coordinates of the target grid dots. Using nonlinear lens-distortion correction, which can be performed at real-time rates (30 frames per second), the mean projection error is less than 0.5 mm at distances up to 25 mm from the endoscope tip, and less than 1.0 mm up to 45 mm. Experimental measurements and point-based registration error theory show that the tracking error is about 0.5-0.7 mm at the tip of the endoscope and less than 0.9 mm for all points in the field of view of the endoscope camera at a distance of up to 65 mm from the tip. It is probable that much of the projection error is due to endoscope tracking error rather than calibration error. Two examples of clinical applications are presented to illustrate the usefulness of image-enhanced endoscopy. This method is a useful addition to conventional image-guidance systems, which generally show only the position of the tip (and sometimes the orientation) of a surgical instrument or probe on reformatted image slices.

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