PubMed Health⌕ Search

Biomedical subjects

W Grant

Publications and source records attributed to W Grant.

At least 37 records · Page 2Linked to original sources
PubMed1996

Proliferative response of human prostate tumour xenografts to surgical trauma and the transurethral resection of the prostate controversy.

Transurethral resection of the prostate (TURP) as an excisional procedure involving multiple incisions into the prostate does not differentiate between palpably benign prostate tissue and microscopic foci of well-differentiated adenocarcinoma. The impact of TURP on the progression of such 'latent' or 'incidental' tumours unique to the prostate gland has been a focal point of a continuing controversy. In studies designed to develop preclinical evidence that would lend support to, or detract from, either side of the TURP controversy, surgical trauma-induced stimulation of in situ tumour growth was extended to include human prostate tumour tissue PC-3, DU-145 and H-1579, albeit as xenografts in athymic nude males. A significant proliferative response of prostate tumours implanted directly in, adjacent to, or distant from, a freshly induced surgical wound, could be inhibited by a somatostatin analogue (Lanreotide) applied topically to the surgical site. This preclinical model supports TURP as a risk factor for biopsy or therapeutic surgical intervention procedures in benign prostatic hypertrophy (BPH), a risk factor that increases with the stage of disease in undetected cancers. It also suggests a potential clinical benefit that might be derived by applying Lanreotide directly to the surgically traumatised genitourinary area by simple irrigation of the urethra and bladder during or shortly post TURP.

Adenocarcinoma↗
PubMed1996

The role of forensic anthropology in the recovery and analysis of Branch Davidian compound victims: assessing the accuracy of age estimations.

Age-at-death estimations of 44 individuals (27 adults, 17 children) from the Branch Davidian sample were compared with their actual ages. Estimations were evaluated for bias and accuracy for the actual age at death. Although the overall average estimates correlated well with the actual ages (r = 0.946), several individuals displayed high residual requiring further analysis and review. These individuals displayed age-related features that did not correspond with the expected morphology for individuals of their ages. Several age estimation techniques scored these individuals with all bias in the same direction. These examples should serve as cautionary reminders that biology does not always correlate with expected outcomes, particularly in such multifaceted traits such as age.

Adult↗
PubMed1995

The role of forensic anthropology in the recovery and analysis of Branch Davidian Compound victims: recovery procedures and characteristics of the victims.

Anthropological contributions to the investigation of the events at the Branch Davidian Compound near Waco, Texas in early 1993, were of two major types: the recovery of human remains from the site and the analysis of most of those individuals at the Medical Examiner's Office in Fort Worth, Texas. This paper describes the role of forensic anthropology in the recovery and analysis of Branch Davidian Compound victims and the recovery procedures and characteristics of the victims.

Adolescent↗
PubMed1994

Composition of the coagulant polysaccharide fraction from Strychnos potatorum seeds.

The composition of the coagulant polysaccharide fraction from Strychnos potatorum seeds is described. This fraction comprises a 1:1.7 mixture of a galactomannan and a galactan. The structure of these polysaccharides is also discussed. In addition, the coagulant properties of the polysaccharide fractions of two other Strychnos species, innocua and nux-vomica, have been assayed.

Carbohydrate Conformation↗
PubMed1994

Fractionated high-dose rate brachytherapy for intracranial gliomas.

PURPOSE: To develop a catheter system for fractionated high-dose rate (HDR) brachytherapy for intracranial gliomas. METHODS AND MATERIALS: The catheter system for stereotactic placement as well as delivery of the high-dose rate iridium-192 source wire is described. The force of the impulse wave from the source wire entering brain equivalent material was measured. Dose volume histograms for the first 5 patients treated are presented. RESULTS: The catheter system was found to be satisfactory. The maximum force of the impulse wave was less than 1 acceleration of gravity (which is safe). The patients tolerated the treatment well with no significant problems related to the catheters being left in situ for up to 14 days. CONCLUSION: Based on this pilot experience a phase I dose escalating and morbidity study has been initiated.

Brachytherapy↗
PubMed1994

Heating rate modeling and measurements in phantom and in vivo of the human upper extremity in a defective 2450 MHz microwave oven.

Multiple door interlock switches in commercial microwave ovens are designed to prevent accidental exposure and injury. We report a) heating rate (degree/sec) measurements in a phantom of the human upper extremity in a 2450 MHz microwave oven having interlock switches deliberately bypassed; b) skin temperature measurements on the upper extremity of a human volunteer similarly exposed; c) perception of warmth and pain experienced by the volunteer during exposure; d) thermographic camera recordings of the volunteer's skin; and e) finite element modeling of specific absorption rate (SAR) in the volunteer's hand. Moderately severe pain was experienced at the fingertips after 5 sec of exposure, consistent with the modeled SAR, measured heating rates, and published data on the temperature threshold for pain. We estimate that an additional 9 sec of exposure would be required to produce irreversible injury, consisting of focal thermal injury in the fingertips and possibly the thenar and hypothenar eminences.

Computer Simulation↗
PubMed1994

Fractionated brachytherapy: catheter insertion and dosimetry.

The incorporation of the Omnitron device, a robotic isotope handling system, into a program of brachytherapy for glial tumors has made it possible to hyperfractionate treatment in 15-20 sessions over a 2- to 3-week period, which offers considerable theoretical advantage over conventional single dose regimens. Stereotactic catheter placement is by contrast-enhanced MR guidance, and takes advantage of the three-dimensional planning offered by voxel orientation. Initial placement is based on orientation to the three customary planes, with oblique planes added to define intercatheter placement more accurately. Catheters may be placed asymmetrically through the tumor or even at different angles of insertion to get the optimal conformation. Dosimetry is based on three-dimensional reconstruction in the Omnitron planning console, and takes advantage of the optimized localization of each catheter position. High-dose isotope insertion is performed robotically, with isotope position and dwell times controlled by computer. The phase I study demonstrates a wide safety margin and suggests better survival than would be expected with conventional management.

Brachytherapy↗
PubMed1993

Do family physicians treat obese patients?

BACKGROUND: The purpose of this study was to characterize what patient and physician factors increase the likelihood of physicians counseling weight loss in their overweight patients. METHODS: A retrospective chart survey of 418 outpatient charts from 50 family medicine residents and faculty was conducted. RESULTS: Of the 267 patients who were overweight based on a body mass index score of more than 27, only 29.6% had been instructed to lose weight. Overweight patients with hypertension, diabetes, hypercholesterolemia, or coronary artery disease were instructed to lose weight 32.9% of the time. Patient age or sex and physician age, sex, or level of training did not affect the frequency of treatment. CONCLUSION: Physicians need to be more aggressive in their counseling of overweight patients.

Adult↗
PubMed1992

Relationships among tumor temperature, treatment time, and histopathological outcome using preoperative hyperthermia with radiation in soft tissue sarcomas.

The lack of an unambiguous thermal dosimetry continues to impede progress in clinical hyperthermia. In an attempt to define better this dosimetry, a model based on the cumulative minutes during which arbitrary percentages of measured tumor temperature points exceeded an index temperature was tested in patients with soft tissue sarcomas treated with preoperative hyperthermia and conventional radiation therapy. Patients received 5000-5040 cGy at 180-200 cGy per fraction. Hyperthermia was delivered 30-60 minutes after radiation therapy and given for 60 minutes. Patients were randomized between one and two hyperthermia treatments per week for a total of five or 10 treatments, respectively. Lesions were excised 4-6 weeks after completion of hyperthermia/radiation therapy. Successful treatment outcome was considered to be the finding of greater than 80% necrosis of the sarcoma upon histopathologic examination of the resected specimen. Forty-five patients were eligible with thermometry data available in 44 patients. An average of 19 interstitial sites were monitored each treatment per tumor. Sixty percent of tumors had a successful histopathologic outcome. Univariate analysis demonstrated that several descriptors of the temperature distribution were strongly related to treatment outcome; more strongly than nonthermometric factors, such as the number of treatments per week, tumor volume and patient age and more strongly than the commonly used temperature descriptors Tmin and Tmax. Descriptors that incorporated both temperature and time were also superior to the more commonly used descriptors Tmin and Tmax. Multivariate stepwise logistic regression analysis revealed that a descriptor of both the hyperthermia treatment time and the frequency distribution of intratumoral temperatures was the strongest predictor of histopathologic outcome and that the best predictive model combined this time/temperature descriptor and one versus two treatment per week grouping. The more conventional temperature descriptor, minimum measured tumor temperature, did not significantly enhance the predictive power of treatment group. Based on these results, we recommend that descriptors based on both the frequency distribution of intratumoral temperatures and hyperthermia treatment time be tested for relationships with treatment outcome in other clinical data bases. Furthermore, we recommend that temperature descriptors that are less sensitive to catheter placement and tumor boundary identification than Tmin and Tmax (such as T90, T50, and T10) be tested prospectively along with other important thermal variables in Phase II trials in further efforts to define a thermal dosimetry for spatially nonuniform temperature distributions.

Combined Modality Therapy↗
PubMed1992

Comparison of enzyme-linked immunosorbent and indirect immunofluorescence assays for the detection of human T-cell lymphotropic virus type-I antibodies in sera from rural Haiti.

Serum samples were obtained from 340 healthy individuals without evidence of neurologic disease living in rural Haiti. Sera were screened for antibodies to human T-cell lymphotropic virus type I (HTLV-I) using two commercially available enzyme immunoassays (EIA) and by an indirect immunofluorescence assay (IFA) using a mixture of uninfected H9 cells and HTLV-I-infected MT-2 cells. Repeatedly positive samples were confirmed by Western blot (WB). Results with the two EIA systems were concordant and detected 13 positive samples, each of which was confirmed by WB. Only 9 (69%) of 13 WB-positive sera were detected by IFA, and four additional samples, positive by IFA, could not be confirmed by WB. The prevalence of HTLV-I seropositivity in this selected rural Haitian population was 3.8% (13 of 340).

Adolescent↗
PubMed1992

Guardianship Orders: a review of their use under the 1983 Mental Health Act.

This article reviews what has been reported in literature about the use of Guardianship Orders under the Mental Health Act 1983. Guardianship Orders were used infrequently in comparison with Sections 2, 3 and 4 of the Mental Health Act although the number of guardianship cases has increased three-fold since 1982. Elderly female patients with organic brain disease were the group on whom guardianship was most used either to support them in the community or to facilitate admission to residential care. Guardianship was rarely used to prevent hospitalization. Despite its many drawbacks, for a selected group of patients guardianship did appear to have advantages and was found to be worthy of consideration for practising clinicians and approved social workers.

Adult↗
PubMed1991

Aminoglycoside induced ototoxicity in patients with cystic fibrosis.

The improved survival of cystic fibrosis (CF) patients is partly due to intensive treatment for their chronic infections. Treatment usually includes intravenous and nebulised aminoglycoside antibiotics and they receive a large cumulative dose of these antibiotics over their lifetime. There is little information in the literature on the prevalence of ototoxicity due to aminoglycoside in these patients. We performed pure tone audiometry on 43 CF patients aged 14-42 years. Seven (16%) had bilateral sensorineural hearing loss (SNHL) for high frequency sounds, consistent with aminoglycoside induced ototoxicity. However, only 2 of these patients had documented toxic serum levels in the past. The identification of bilateral SNHL in one in six adult CF patients is a cause for concern. It may be that the high cumulative dose of aminoglycosides received by these patients may be causing inner ear injury in the absence of specific episodes of toxic serum levels.

Adolescent↗
PubMed1991

Pain response to sagittal end-range spinal motion. A prospective, randomized, multicentered trial.

This article reports a prospective, randomized, multicentered study documenting changes in the intensity and location of low-back and referred pain to repeated end-range lumbar flexion and extension movements performed first while standing and then while recumbent during a single clinical patient evaluation. Significant and rapid changes in central and distal pain intensity and location of peripheral pain resulted from the performance of these movements. For the mean in both protocols, regardless of the order of spinal movements, end-range extension significantly decreased central and distal pain intensity and centralized referred pain. Flexion spinal movements, however, significantly increased mean central and distal pain intensity and peripheralized the pain. Forty percent of individual subjects had a clear preference for extension and 7% a clear preference for flexion.

Adult↗
PubMed1990

Use of guardianship under the 1983 Mental Health Act.

The powers of guardianship under the 1983 Mental Health Act confer on the guardian powers to require the patient to reside in a specified place, to require attendance for treatment and to require access to the patient for appropriate health and social services personnel. This paper presents a descriptive study and analysis of the use of guardianship over a 5-year period in four geographical areas. Cases were collected retrospectively from a variety of sources and scrutinized systematically. Three cases of guardianship for mental impairment were excluded from the analysis leaving 23 patients with mental illness. All but two of the patients were female. Older patients, mostly with dementia, accounted for three-quarters of the sample and the majority of orders in this group were to require residence in an old people's home (usually with an apparently good outcome), though three were intended to facilitate home care. In most of the younger patients a functional psychiatric illness was diagnosed and powers were used to maintain the patient at home. The absence of a specific 'power to convey' needs to be resolved for elderly patients needing residential care. The use of guardianship orders to maintain older patients in the community needs further exploration.

Adult↗
PubMed1987

Otolith-organ mechanics: lumped parameter model and dynamic response.

The otolith organs comprise a second-order system whose response is overdamped and whose dynamics can be expressed by two time constants. The long time constant has been experimentally measured at 10 s. The short time constant is approximately 0.0002 s using a maximum mechanical displacement criterion for the otoconial layer. With these two values determined, the system dynamic response indicates that, between the two system corner frequencies, the peripheral sensory cells (primary Type II cells) report skull velocity information to the central nervous system, and striolar cells (primary Type I cells) report skull acceleration information to the central nervous system. Below the lower corner frequency, peripheral sensory cells report skull acceleration information to the central nervous system, and striolar sensory cells report rate of change of acceleration information to the central nervous system.

Acceleration↗