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PubMedDate not supplied

Effect of caries experience in primary molars on cavity formation in the adjacent permanent first molar.

This study sought to address the influence of a sound versus affected first and/or second deciduous molar on the incidence of visible caries experience in the adjacent permanent first molar. Clinical and questionnaire data were obtained from a 6-year prospective oral health screening project in Flanders, Belgium (Signal-Tandmobiel project), where 4,468 children (born in 1989) were examined annually during their primary school time. A multiple survival model allowing for dependent data with possible censoring was applied. The impact of timing of tooth emergence (determining the period at risk), gender, presence of sealants and reported oral hygiene habits was also considered. Cavity formation in permanent first molars was clearly influenced by the status of the adjacent primary molars;the effect of the second deciduous molar was most pronounced. Moreover, if both deciduous molars experienced caries and the child presented with poor oral hygiene, a peak in cavity formation of the permanent first molar 1-2 years after emergence was noticed. On the other hand, if a child presented with good oral hygiene, no peak was observed; caries risk increased slightly over time. No significant benefit from restoring primary molars could be demonstrated, possibly because of methodological limitations.

Child↗

PubMed2002

Comparison of three-dimensional rotational angiography with digital subtraction angiography in the assessment of ruptured cerebral aneurysms.

BACKGROUND AND PURPOSE: Rotational angiography (RA) and digital subtraction angiography (DSA) together may depict more intracranial aneurysms than DSA alone. We compared the diagnostic value of 3D RA and biplanar DSA in detecting, classifying, and planning treatment for ruptured intracranial aneurysms. METHODS: A total of 53 patients with acute subarachnoid hemorrhage (Hunt and Hess grades I-V) underwent angiography with both methods. DSA was performed in two to six standard projections in every vascular territory. Three-dimensional RA datasets were evaluated by using surface-shaded display and maximum intensity projection. The usefulness of DSA images and 3D datasets in detecting aneurysms (number, configuration) and treatment planning were retrospectively analyzed in a blinded manner. RESULTS: In 42 patients, 56 aneurysms were detected, (one to five per patient; size, 0.6-20.4 mm); no aneurysm was found in 11 patients. RA revealed seven aneurysms not seen at conventional DSA. RA failed to depict one aneurysm visible only in a compression series. Delineation of the aneurysmal neck improved with RA in 71% of cases; the parent vessel and its relationship to adjacent vessels was demonstrated better with RA than with DSA in 45% and 50%, respectively. Endovascular treatment was proposed in nine patients; microsurgical therapy, in 26. In seven patients, both options were rated as being equal. Actual treatment consisted of eight endovascular procedures and 30 neurosurgical operations. Four patients died before therapy. CONCLUSION: Compared with DSA, 3D RA allows more exact depiction of anatomic details that are important in planning surgery and interventional therapy for intracranial aneurysms. RA depicted more aneurysms.

Adult↗

PubMed2003

Long microvilli of mesothelioma are conspicuous in pleural effusions processed by Ultrafast Papanicolaou stain.

BACKGROUND: The differentiation of malignant epithelial mesothelioma, nonmucinous pulmonary adenocarcinoma, and mesothelial hyperplasia by direct light microscopic examination is challenging. The detection of long microvilli, an ultrastructural feature unique for malignant epithelial mesothelioma, requires immunolabeling of epithelial membrane antigen to be visible by light microscopy. The purpose of this study is to report that this feature is now made conspicuous enough to be detected by light microscopy by a different approach in cytologic processing. METHODS: The study includes 9 cases of mesothelioma, 50 cases of mesothelial hyperplasia, and 50 cases of nonmucinous pulmonary adenocarcinoma. Direct smears were made from the sediments of fresh or refrigerated effusions, air dried, rehydrated with normal saline for 30 seconds to create retraction halos, and processed with the Ultrafast Papanicolaou stain (UFP). RESULTS: Long microvilli in thick bundles as well as short, fine projections radiating from the free surface of the epithelial mesothelioma cells were observed within the retraction halos in pleural effusions processed by UFP. These features were not observed in the UFP-processed hyperplastic mesothelial cells or in the pulmonary nonmucinous adenocarcinoma cells. CONCLUSION: Direct visualization of long microvilli via UFP may aid in the distinction of malignant mesothelioma from mesothelial hyperplasia and adenocarcinoma before immunohistochemical and electron microscopic studies are performed.

Adenocarcinoma↗

PubMed2006

Integrating respiratory gating into a megavoltage cone-beam CT system.

We have previously described a low-dose megavoltage cone beam computed tomography (MV CBCT) system capable of producing projection image using one beam pulse. In this study, we report on its integration with respiratory gating for gated radiotherapy. The respiratory gating system tracks a reflective marker on the patient's abdomen midway between the xiphoid and umbilicus, and disables radiation delivery when the marker position is outside predefined thresholds. We investigate two strategies for acquiring gated scans. In the continuous rotation-gated acquisition, the linear accelerator (LINAC) is set to the fixed x-ray mode and the gantry makes a 5 min, 360 degree continuous rotation, during which the gating system turns the radiation beam on and off, resulting in projection images with an uneven distribution of projection angles (e.g., in 70 arcs each covering 2 degrees). In the gated rotation-continuous acquisition, the LINAC is set to the dynamic arc mode, which suspends the gantry rotation when the gating system inhibits the beam, leading to a slightly longer (6-7 min) scan time, but yielding projection images with more evenly distributed projection angles (e.g., approximately 0.8 degrees between two consecutive projection angles). We have tested both data acquisition schemes on stationary (a contrast detail and a thoracic) phantoms and protocol lung patients. For stationary phantoms, a separate motion phantom not visible in the images is used to trigger the RPM system. Frame rate is adjusted so that approximately 450 images (13 MU) are acquired for each scan and three-dimensional tomographic images reconstructed using a Feldkamp filtered backprojection algorithm. The gated rotation-continuous acquisition yield reconstructions free of breathing artifacts. The tumor in parenchymal lung and normal tissues are easily discernible and the boundary between the diaphragm and the lung sharply defined. Contrast-to-noise ratio (CNR) is not degraded relative to nongated scans of stationary phantoms. The continuous rotation-gated acquisition scan also yields tomographic images with discernible anatomic features; however, streak artifacts are observed and CNR is reduced by approximately a factor of 4. In conclusion, we have successfully developed a gated MV CBCT system to verify the patient positioning for gated radiotherapy.

Electrons↗

PubMedDate not supplied

Prevalence of goiter in a rural community in Sri Lanka.

The prevalence of goiter in a rural community was determined in a defined geographical area, namely, the Hindagala Community Health Project (HCHP). In this area which is divided into six Public Health Midwife (PHM) areas, the mean altitude varies from 450 to 775 meters. The house-to-house goiter survey conducted by the trained field health staff covered 70% of the population. The total goiter prevalence was 7% while the prevalence of visible goiter was 2.8%. The goiter prevalence was higher in the females than in the males at all age groups. Among males, the prevalence was highest in the school-going age group 6-18 years, while among females the highest prevalence was in the early childbearing period of 19-34 years. Further, an increasing trend in the prevalence was observed with increase in mean altitude of the PHM area. Correlation between community prevalence and age-sex specific prevalence gave the best relationship with the 6-18 year age group and a regression equation to predict the community prevalence from the prevalence in the school-going age group is presented.

Adolescent↗

PubMed1986

The influence of anatomic evolution of coronary artery disease on left ventricular contraction: an angiographic follow-up study of 300 nonoperated patients.

The impact of the evolution of obstructive coronary artery disease (CAD) on left ventricular (LV) function was studied in 300 nonoperated patients who had had two angiographic studies. The interval between studies ranged from 6 months to 10 years (mean 29.6 months). Quantitative analysis of LV contractions in right anterior oblique projections was performed with the use of a computer program for calculation of ejection fraction (EF) and regional wall motion (RWM) according to the method of Leighton. No progression of CAD was found in 131 patients. Progression of CAD was found in 169 patients. In the patients without progression and in 75 patients who had progression to less than total obstruction, no changes in EF and RWM were found. In the 67 patients in whom progression from less than 90% narrowing to occlusion had occurred a significant decrease in EF and RWM was found. In the 27 patients with progression from subtotal narrowing to occlusion, however, no change in LV function was found. A myocardial protective value of angiographically visible preexistent collaterals could not be demonstrated. We conclude that absence of progression of CAD implies that LV function does not deteriorate and that slow progression to occlusion, via a stage of subtotal narrowing, generally does not influence LV function.

Cardiac Catheterization↗

PubMedDate not supplied

Blue-dye sentinel node mapping in thyroid carcinoma: debatable results of feasibility.

The present study aims to investigate the feasibility and influence of the lymphatic mapping and sentinel node biopsy on determination of the nodal status in thyroid carcinoma using blue-dye method. Nine consecutive patients with cytological diagnosis of papillary carcinoma were included in this study. To detect the sentinel lymphnode, intra- or perinodular injection of an average quantity of 0.5 ml (range : 0.1-1.2) of Ble Patenté V was performed intraoperatively in 8 cases only, as in one case a solitary cystic nodule occupied the entire lobe and thus any injection was impossible. After an average time of 16 minutes (range : 5-25) before dissection of the thyroid , no lymphnodes and no lymphatic afferent thereto visibly coloured were evidenced, except for spread of the vital dye into adjacent tissue and disrupted blood and lymphatic vessels at the injection site. Our results evidence that : intranodular injection, does not allow proper diffusion of the dye in the adjacent parenchyma, and in nodules smaller than 1 cm it may be difficult ; and that it is hazardous in cystic nodule because of the rupture risk; perinodular injection, at the four cardinal points, is impossible when the nodule occupies the entire lobe or the isthmus; multinodular goiter complicates the identification by palpation of the neoplastic nodule in which the dye should be injected or, if perinodular injection is given, to detect the parenchyma surrounding the nodule.

Adult↗

PubMed1997

Threaded titanium cages for lumbar interbody fusions.

STUDY DESIGN: This study evaluated safety, fusion success rate, and clinical outcome of a new lumbar interbody hollow, threaded titanium fusion cage in a multicenter, prospective 236-case program adhering to a United States Food and Drug Administration Investigational Device Exemption controlled protocol. OBJECTIVES: The results were evaluated to demonstrate the safety and effectiveness of this new method to achieve solid lumbar interbody fusions. SUMMARY OF BACKGROUND DATA: Interbody fusions have certain distinct mechanical advantages over lateral or posterolateral ones. Autologous, cancellous bone is the preferred graft material, but is too soft to maintain the space during fusion without mechanical support. Various methods have been used in the past to maintain the graft integrity during fusion development. METHODS: An initial pilot study began on 10 patients (followed for 84 months, average 80 months). Two years after that investigation started, the multicenter United States Food and Drug Administration Investigational Device Exemption study began, with cases followed for 28-46 months (average, 32). Ninety-six percent of the investigational Device Exemption study cases had severe, disabling back pain; in addition, 74% had major annular degeneration; 57% had herniations; 21% had osteophytes; and 43% had disc height reduced by greater than 10%. Forty-five percent of cases had previous spinal surgeries, and none were posterior lumbar interbody fusions. Titanium fusion cage pairs were screwed into bored and threaded, parallel intradiscal holes, and 3-8 ml autologous cancellous bone was packed inside each. Fusion success was judged by absence of motion on flexion-extension radiographs, absence of bone halo around the implants, and maintenance of visible bone inside the cages on Ferguson view radiographs. RESULTS: Segments fused rapidly; the pilot study cases fused at 10 (91%) of 11 levels, with a reported 80% average clinical improvement. Ninety-six percent of the 208 2-year follow-up Investigational Device Exemption cases had fusion, and the Prolo socioeconomic/ functional improvement scale showed: 40% excellent, 25% good, 21% fair, and 14% poor results. Less than 1% of Investigational Device Exemption cases had complications that persisted beyond the average 5 days of hospitalization, and none were serious. CONCLUSIONS: The Ray titanium fusion cage (Surgical Dynamics, Norwalk, CT) implant method has been found to be an effective, rapid, safe procedure for lumbar spine fusions, demonstrating a high fusion rate and clinical success with rare, serious, or permanent complications.

Adolescent↗

PubMed1997

A pilot study to determine the order of emergence of permanent central incisors and permanent first molars of children in the Colchester area of the U.K.

Over the period of one calendar month, 505 children in the Colchester area of England were examined. The data gathered from the 12 non-Caucasian children was not used, leaving 493 Caucasian children (255 boys and 238 girls). Their mean age was 6.48 years, with a range of 4.49-8.75 years and 164 children had no permanent teeth leaving 329 children with a total of 2,238 permanent teeth present. A permanent tooth was deemed to have emerged if any part of it was visible in the mouth. The forensic significance of the results of this pilot study are that there is no significant difference (t = 0.407, P > 0.2) between the age of emergence of permanent central incisors (mean age 6.23 years) and permanent first molars (mean age 6.29 years). On the whole, lower central incisors emerge before upper central incisors and there is no significant difference (t = 0.899, P > 0.2) in the emergence times of upper and lower permanent first molars. There is no significant difference (t = 0.876, P > 0.2) in the emergence times of permanent central incisors for boys and girls (6.22 and 6.25 years respectively) and there is no significant difference (t = 1.413, P > 0.1) in the emergence times of permanent first molars for boys and girls (6.40 and 6.08 years respectively).

Age Factors↗

PubMed2005

Magnetic resonance-guided percutaneous angioplasty of femoral and popliteal artery stenoses using real-time imaging and intra-arterial contrast-enhanced magnetic resonance angiography.

OBJECTIVE: The aim of this study was to demonstrate the possibility of performing magnetic resonance (MR)-guided interventional therapy for femoral and popliteal artery stenoses with commercially available materials supported by MR real-time imaging and intra-arterial MR angiography. MATERIALS AND METHODS: A total of 15 patients suffering from symptomatic arterial occlusive disease of the lower limbs with 19 stenoses were included. Interventional intra-arterial digital subtraction angiography was performed before and after angioplasty on each patient as standard of reference. MR images were acquired on a 1.5-T MR scanner. A fast-low-angle shot (FLASH) 3D sequence was applied for a contrast enhanced MR-angiography (ceMRA). A total of 5 mL of diluted gadodiamide was injected via the arterial access. Maximum intensity projections (MIPs) were used as roadmaps and localizers for the interactive positioning of a continuously running 2D-FLASH sequence with a temporal solution of 2 images/second. The lesion was crossed by a balloon-catheter, which was mounted on a guidewire. The visibility was provided by the radiopaque markers on the balloon and was improved by injection of 1 mL of gadolinium into the balloon. Postinterventional control was performed by intra-arterial MR angiography and catheter angiography. RESULTS: Stenoses were localized by intra-arterial MR angiography. The guidewire/balloon combination was visible, and the balloon was placed correctly to cover the entire stenoses. Balloon dilation reduced the degree of stenosis by approximately 57% on average. No complications were observed. CONCLUSION: MR-guided balloon dilation of femoral and popliteal artery stenoses supported by real-time MR imaging and intra-arterial MR angiography is feasible with commercially available materials.

Aged↗

PubMed2006

Progress and prospects on melanoma: the way forward for early detection and reduced mortality.

The public health problem of melanoma is difficult. Recent decades have seen substantial efforts directed at primary prevention, yet the incidence of melanoma continues to increase. Substantial efforts have been devoted to improving treatment, yet melanoma retains a poor prognosis if simple surgical excision is not curative. Early detection has made remarkable progress, however. Five-year relative survival has increased from approximately 80% in 1975 to greater than 90% in 1996. Even so, almost 8,000 Americans are projected to succumb to melanoma in 2005. Because most of these fatal melanomas are visible on the skin surface at a curable phase in their evolution, more can and must be done. To improve the early detection practices of clinicians, we have developed an eight-step Basic Skin Cancer Triage algorithm, which forms the core of a curriculum that we have shown can result in improved skills, attitudes, and practices. We are now in the process of attempting to test a Web-based version of that curriculum in a randomized trial. Skin self-examination also has tremendous potential for contributing to early detection of melanoma. We have tested an intervention to encourage thorough skin self-examination in a randomized trial and found it effective in increasing the performance of this procedure, on increase that is sustained for at least a year, while resulting in only short-term increases in surgical procedures on the skin. Early detection has not yet reached its full potential effect on the public health problem of melanoma and is poised to further reduce melanoma mortality.

Humans↗

PubMedDate not supplied

Can the social model explain all of disability experience? Perspectives of persons with chronic fatigue syndrome.

OBJECTIVE: The social model of disability has had a major influence on the academic field of disability studies and on contemporary understandings of the causes and experience of disability. The purpose of this study was to examine the adequacy of the social model for explaining the disability experience of persons with chronic fatigue syndrome (CFS). METHODS: This qualitative study examined the experiences of 47 adults with CFS participating in a research project that aimed to evaluate a participant-designed rehabilitation program. Data were aggregated from focus group interviews, open-ended questionnaires, progress notes, and from a program evaluation questionnaire. Data analysis was based on a grounded theory approach and used triangulation of multiple data sources and member checks to assure dependability of findings. RESULTS: Four themes emerged from the analysis: (1) minimization and mistrust of the disability; (2) negative experiences of impairment; (3) lack of identification with the disability community; and (4) the focus on advocacy as a quest for legitimacy. These themes varied in the extent to which they conformed to the principles set forth by the social model. CONCLUSIONS: Although the social model has important contributions to lend to occupational therapy practice, it is important to recognize that it may not capture the full reality of disability. In particular, the social model has serious limitations in describing the disability experience of individuals with disabilities who do not have visibly obvious disabilities and whose impairments do not conform to the traditional viewpoint of disability.

Adult↗

PubMed2003

[Giant myelolipoma of the adrenal gland].

INTRODUCTION: Myelolipoma is a rare benign tumor of adrenal gland, composed from a fatty tissue and hematogenous elements. It may be associated with endocrine disorders such as androgyneity, Cushing's disease, Addison's disease and other causes including obesity. It may also occur as a soft-tissue mass in various regions, especially in the area of small pelvis. Giant myelolipomas of adrenal gland have rarely been described in the world literature and it was considered useful to describe this case. CASE REPORT: A 54-year woman was examined in an internal ward for arterial hypertension and an ultrasound abdominal examination was therefore indicated. The finding was later confirmed by CT examination, which demonstrated a sizable expansion with fatty densities and a stroma, which was slightly more visible after the administration of a contrast compound, projecting in the region of the right adrenal gland. CONCLUSION: The formation is most probably a myelolipoma. No disease-related symptoms were detected. A surgical extirpation of three tumors of the same character was made. The diameter of the largest tumor was at least 140 mm. The diagnosis of myelolipoma was confirmed by histological examination. The patient was cured up and released from the hospital on day 12 after the operation. CONCLUSIONS: The tumor is without symptoms in most cases, but bleeding or rupture may occur. It is rarely associated with endocrine disorders. Etiology is so far not clear. The diagnosis can be established by US, CT or MR examination. The operation is indicated in patients with symptoms, tumor of large size, in case of bleeding etc. Small tumors may be followed subsequently. The surgical intervention, extirpation of the tumor, may also be done by laparoscopy. This paper appears to be the first published information about myelolipoma of adrenal grand, especially of such considerable size, in the Czech medical literature.

Adrenal Gland Neoplasms↗

PubMed1979

Reflections on the current status of the national sickle cell disease program in the United States.

Some clouds of concern now appear on the horizon for the national sickle cell disease program. There is flagging general attention by the black population and a dilution of interest in and visibility of the sickle cell problem brought about by political maneuvering to bring the program under the legislative umbrella of many other genetic diseases (which occur predominantly in Caucasians). In addition, the federal program has recently phased-out six comprehensive sickle cell centers and imposed budgetary cutbacks in the remaining centers. The victims of this disease, the black population in general, and the researchers and investigators who seek ways to bring this disease under control need reassurance from the current national administration that the sickle cell program will not be permitted to die a slow death from financial attrition, attenuation of interest, and skillful neglect leading to the phasing-out of another "minority project." The national sickle cell program, in the relatively short span of six years, has made significant and notable progress not only in research endeavor but also in improved patient care and community-wide education. In this context, certainly, the positive aspects of the national sickle cell disease program continue to far outweigh any negative ones.(1)

Anemia, Sickle Cell↗

PubMed2001

Information limitations in perception of shape from texture.

Li and Zaidi (Li, A., and Zaidi, Q. (2000) Vision Research, 40, 217-242) showed that the veridical perception of the 3-dimensional (3D) shape of a corrugated surface from texture cues is entirely dependent on the visibility of critical patterns of oriented energy. These patterns are created by perspective projection of surface markings oriented along lines of maximum 3D curvature. In images missing these orientation modulations, observers confused concavities with convexities, and leftward slants with rightward slants. In this paper, it is shown that these results were a direct consequence of the physical information conveyed by different oriented components of the texture pattern. For texture patterns consisting of single gratings of arbitrary spatial frequency and orientation, equations are derived from perspective geometry that describe the local spatial frequency and orientation for any slant at any height above and below eye level. The analysis shows that only gratings oriented within a few degrees of the axis of maximum curvature exhibit distinct patterns of orientation modulations for convex, concave, and leftward and rightward slanted portions of a corrugated surface. All other gratings exhibit patterns of frequency and orientation modulations that are distinct for curvatures on the one hand and slants on the other, but that are nearly identical for curvatures of different sign, and nearly identical for slants of different direction. The perceived shape of surfaces was measured in a 5AFC paradigm (concave, convex, leftward slant, rightward slant, and flat-frontoparallel). Observers perceived all five shapes correctly only for gratings oriented within a few degrees of the axis of maximum curvature. For all other oriented gratings, observers could distinguish curvatures from slants, but could not distinguish signs of curvature or directions of slant. These results demonstrate that human observers utilize the shape information provided by texture components along both critical and non-critical orientations.

Form Perception↗

PubMed2001

Erratum to "Information limitations in perception of shape from texture". [Vision Research 41 (2001) 1519-1534].

Form Perception↗

PubMed2005

Imaging dose management using multi-resolution in CT-guided radiation therapy.

In image-guided radiation therapy, megavoltage computerized tomography (MVCT) delivers higher dose to the patient for lower image quality than diagnostic kilovoltage CT (kVCT). One way to reduce the mean imaging dose is to reduce the imaging volume, which is often sufficient for registration and dosimetry purposes. The filtered back projection using truncated data causes artefacts that degrade the image quality. Those artefacts can be effectively reduced by wavelet-based multi-resolution analysis (WMRA), in which the detail and approximate information are reconstructed separately to bypass the non-locality of filtered back projection. In this study, WMRA was used to reconstruct local images from both very low-dose kVCT scans from a bench-top tomotherapy unit and MVCT scans from helical tomotherapy. Results show that mean imaging dose can be significantly reduced by imaging a small region of interest. In simulation, the root-mean-square error brought by the truncation is smaller than 1-2% and depends on the level of dose reduction. On the other hand, the same mean dose that would have been delivered by a low-quality global CT can be conformed to a smaller volume to improve the visibility of low-contrast organs and fine structures using WMRA. Organs at risk can be avoided during repeated daily CT imaging when irregular-shaped reconstruction areas are used. WMRA does not involve computationally expensive iterations and is suitable for image-guided radiation therapy where imaging speed is essential. Compared with extrapolation methods, errors are further reduced to improve the detection of low contrast and fine structures.

Algorithms↗

PubMed2001

Evaluation of prospective living renal donors for laparoscopic nephrectomy with multisection CT: the marriage of minimally invasive imaging with minimally invasive surgery.

Laparoscopic technique for excision of a kidney from a living donor has advantages over conventional open surgery, but operative visibility and surgical exposure are limited. Preoperative multisection computed tomography (CT) can provide necessary anatomic information in a minimally invasive procedure. A three-phase examination is suggested: (a) imaging from the top of the kidneys to the pubic symphysis with a section width of 2.5 mm and no contrast medium, (b) scanning of the kidneys and upper pelvis during the arterial phase of enhancement with a section width of 1.0 mm, and (c) scanning of the kidneys and upper retroperitoneum during the nephrographic phase of enhancement with a section width of 1.0 mm. Emphasis in this article is placed on analysis of the venous anatomy because most radiologists are unfamiliar with the anatomic variations. Conventional radiography of the abdomen and pelvis is performed after CT to evaluate the collecting system and ureters and to provide a lower total radiation dose than if CT were used. Of several postprocessing techniques that may be used, the authors prefer maximum intensity projection for arterial evaluation and multiplanar reformatting for venous evaluation.

Humans↗