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Biomedical subjects

C Sherman

Publications and source records attributed to C Sherman.

At least 19 recordsLinked to original sources

The predictive value of diagnostic imaging for histological lesions of the upper poles in duplex systems with ureteroceles.

OBJECTIVE: To compare the diagnostic imaging findings with the histological lesions in upper pole nephrectomy (UPN) specimens of duplex system ureteroceles, using renal ultrasonography (US) and nuclear renal scintigraphy. PATIENTS AND METHODS: Between 1992 and 2000, 86 patients with a ureterocele in a duplex system underwent surgery. The results from US were reviewed in 84 patients by a radiologist, for echogenicity, parenchymal thinning and hydronephrosis; 77 nuclear renal scans describing the differential function of the upper poles were also reviewed. Fifty-five patients underwent UPN (25 antenatal, 30 postnatal; 18 intravesical, 37 extravesical) and the specimens were available for independent review by a pathologist, describing five histological categories, i.e. chronic interstitial inflammation, fibrosis, tubular atrophy, glomerulosclerosis and dysplasia. Histological lesions were categorized as severe (> 25%) or minimal (<or= 25%). Radiological features and the histology of UPN were then analysed, and correlated using Fisher's exact test and multivariate analysis. RESULTS: Severe histological lesions were reported in 38 specimens (69%) and minimal lesions in 17 UPN specimens (31%). Severe parenchymal thinning was associated with a severe pathological lesion (P < 0.02). There was no correlation with the echogenicity or degree of hydronephrosis. Dysplasia, found in 64% of specimens, did not correlate with increased echogenicity. Minimally functioning upper poles on nuclear renal scan (<or= 4% overall function) were significantly associated with severe histological lesions (P = 0.01). There was no correlation between diagnostic imaging features and the mode of presentation or type of ureterocele. CONCLUSIONS: Multivariate analysis, severe parenchymal thinning on renal US and minimal function on nuclear renal scan can be used to predict the severity of histological lesions of the upper pole. These results may be helpful in the making therapeutic decisions for patients with ureteroceles in duplex systems.

Adolescent↗

Tyrosine phosphorylation in human lymphomas.

In a previous study, we showed that the high level of protein tyrosine phosphorylation present in lymphomas containing an anaplastic lymphoma kinase (ALK) can be demonstrated in routinely processed paraffin tissue sections using immunolabelling techniques. In the present study we investigated whether oncogenic tyrosine kinase activation also occurs in other categories of lymphoma by staining 145 cases of lymphoma covering those tumours with a range of different subtypes including those with morphological similarity to ALK-positive anaplastic large cell lymphoma (ALCL). Twelve cases of the borderline malignant disorder lymphomatoid papulosis were also studied. Twenty seven of the 28 cases of ALK-positive ALCL showed the extensive cytoplasmic labelling for phosphotyrosine in the neoplastic cells. The remaining case containing moesin-ALK exhibited membrane-associated phosphotyrosine expression. There was no nuclear phosphotyrosine labelling in any of the ALK-positive ALCL, even though ALK was present within the cell nuclei in 23 of the tumours. Variable degrees of phosphotyrosine labelling, usually membrane-restricted, were observed in 7/40 cases of ALK-negative ALCL, 9/29 cases of diffuse large B-cell lymphoma, 3/6 cases of mediastinal B-cell lymphoma, 2/7 cases of Hodgkin's lymphoma, 3/6 cases of peripheral T-cell lymphomas unspecified, 4/6 cases of B-cell chronic lymphocytic leukaemia, 2/6 cases of follicular lymphomas and 2/12 cases of lymphomatoid papulosis studied. However none of these phosphotyrosine-positive cases showed the strong cytoplasmic labelling comparable to that seen in ALK-positive lymphoma. We conclude that activation of a tyrosine kinase is probably not a major oncogenic event in lymphomas other than ALK-positive ALCL.

Cell Nucleus↗

Effects of withdrawal of inhaled steroids in men with severe irreversible airflow obstruction.

Inhaled corticosteroid therapy has proven efficacy for asthmatics, but the benefit for patients with chronic obstructive pulmonary disease (COPD) is less well supported. We hypothesized that withdrawal of inhaled steroids in elderly patients with severe irreversible airway obstruction would not lead to a deterioration in respiratory function. We designed a prospective, double-blind, randomized, placebo-controlled, crossover study to follow spirometry, quality of life questionnaire, six-minute (6-min) walk test, and sputum markers of inflammation during a 6-wk placebo treatment period and a 6-wk treatment period with beclomethasone dipropionate (BDP), 336 microg/d. There were 24 men receiving BDP who entered the study; 15 completed the study. Their mean age was 66.9 +/- 1.9 yr, and mean FEV(1) was 1.61 +/- 0.1 L (47% of predicted). There was a significant decrease in the mean FEV(1 )while using the placebo inhaler (1.70 L versus 1.60 L, baseline versus placebo: 95% CI, 0.002 to 0.195; p < 0.05). There was a decrease in the mean percentage change in FEV(1) for the study subjects during the placebo treatment period as compared with the BDP treatment period (-6.28 versus 5.03%, placebo versus BDP: 95% CI, -23.38 to 0.76; p = 0.06). Six-minute walk test results and sputum analysis for cell count and differential were not significantly different during placebo and BDP treatment periods. Borg scale assessment of dyspnea after exercise was increased while using the placebo inhaler as compared with baseline, and decreased during the BDP treatment period. Chronic Respiratory Disease Questionnaire (CRQ) scores revealed no significant difference between placebo and BDP. This study has demonstrated that in elderly patients with severe irreversible airway obstruction, withdrawal of inhaled corticosteroid therapy leads to a deterioration in ventilatory function and increased exercise-induced dyspnea.

Administration, Inhalation↗

Visual expertise in the perception of action.

Within the exercise and the sports sciences, various "expert observers" rely on visual assessments of movement. Strengths and limitations of unaided observation are outlined based on the biological motion perception literature and related work. The concepts of coordination, control, and action are used to propose an "action prototype" for pattern recognition.

Biomechanical Phenomena↗

Evaluation of the efficacy of lambda-cyhalothrin applied as ultra-low volume and thermal fog for emergency control of Aedes aegypti in Honduras.

An extended-duration formulation of lambda-cyhalothrin (Demand CS) applied as either an ultra-low volume (ULV) or thermal fog spray from a new handheld sprayer (Terrier) against Aedes aegypti was evaluated in Honduras. Spray applications were made at the front door for 1 min or to each room for 15 sec, both for the ULV and thermal fog applications to houses in separate blocks for each treatment. The efficacy and duration of effectiveness of the spray was determined from sentinel caged mosquito mortality and collection of mosquitoes within houses with a backpack power aspirator. Sentinel caged mosquito mortality in both open and sequestered locations was 97-100% for all spray treatments, with control mortality less than 2%. Both ULV applications (front door and each room) provided 4 wk of significant control (P < 0.01) based on adult Ae. aegypti house collections.

Aedes↗

Fossiliferous Lana'i deposits formed by multiple events rather than a single giant tsunami.

Giant tsunamis, generated by submarine landslides in the Hawaiian Islands, have been thought to be responsible for the deposition of chaotic gravels high on the southern coastal slopes of the islands of Lana'i and Moloka'i, Hawaii. Here we investigate this hypothesis, using uranium-thorium dating of the Hulopoe gravel (on Lana'i) and a study of stratigraphic relationships, such as facies changes and hiatuses, within the deposit. The Hulopoe gravel contains corals of two age groups, representing marine isotope stages 5e and 7 (approximately 135,000 and 240,000 years ago, respectively), with significant geographical and stratigraphic ordering. We show that the Hulopoe gravel was formed by multiple depositional events, separated by considerable periods of time, thus invalidating the main premise of the 'giant wave' hypothesis. Instead, the gravels were probably deposited during interglacial periods (when sea level was relatively high) by typical Hawaiian shoreline processes such as seasonal wave patterns, storm events and possibly 'normal' tsunamis, and reached their present height by uplift of Lana'i.

Animals↗

Mismatch repair gene defects contribute to the genetic basis of double primary cancers of the colorectum and endometrium.

Hereditary non-polyposis colorectal cancer (HNPCC) is a dominantly inherited cancer syndrome caused by germline defects of mismatch repair (MMR) genes. Endometrial cancer is the most common extracolonic neoplasm in HNPCC and is the primary clinical manifestation of the syndrome in some families. The cumulative incidence of endometrial cancer among HNPCC mutation carriers is high, estimated to be from 22 to 43%. We hypothesized that women with double primary cancers of the colorectum and endometrium are likely to be members of HNPCC families. In order to determine how frequently HNPCC manifests in the context of double primary cancers, we examined alterations of two MMR genes, hMSH2 and hMLH1, in 40 unrelated women affected with double primary cancers. These cases were identified using hospital-based and population-based cancer registries in Ontario, Canada. MMR gene mutations were screened by single-strand conformation polymorphism analysis and confirmed by direct sequencing. Eighteen percent (seven of 40) were found to harbor mutations of one of the two MMR genes. Analysis of colorectal and/or endometrial tumors of mutation-negative probands found microsatellite instability in seven of 20 cases. Six of seven mutation-positive probands had strong family histories suggestive of HNPCC. First degree relatives of mutation-positive probands had a very high relative risk (RR) of colorectal cancer (RR = 8.1, CI 3. 5-15.9) and endometrial cancer (RR = 23.8, CI 6.4-61.0). The relative risk of mutation-negative cases was 2.8 (CI 1.7-4.5) for colorectal cancer and 5.4 (CI 2.0-11.7) for endometrial cancer. We recommend that all double primary patients with cancers at these sites should have a genetic evaluation, including molecular analysis for HNPCC where appropriate.

Adaptor Proteins, Signal Transducing↗

Trial of a community-based intervention to decrease infestation of Aedes aegypti mosquitoes in cement washbasins in El Progreso, Honduras.

Washbasins and metal drums are important sources of Aedes aegypti mosquitoes in much of Latin America. When manual cleaning was found to be ineffective in eliminating mosquito larvae in a community-based control programme in El Progreso, Honduras, it was decided to develop and evaluate an improved method of removing mosquito eggs based on commonly-available materials. The method, named La Untadita ('The Little Dab', in English), consists of five steps: mixing chlorine bleach and detergent to make a paste, applying the mixture to the walls of the container, waiting 10 min, scrubbing with a brush, and finally rinsing with water. A field trial of the Untadita was conducted in 13 peri-urban neighbourhoods. At the first post-intervention survey, in spite of high levels of exposure to the community-based intervention, high levels of knowledge regarding the Untadita and high levels of its reported use, little or no impact was discernable on mosquito larvae and pupae. The method was then modified by increasing the recommended quantities of bleach and detergent and simplifying the instructions. In the second post-intervention survey, knowledge of the steps and their order increased further; the intervention neighbourhoods had significantly fewer algae on washbasin walls, an indicator of more effective cleaning; and numbers of pupae and 3rd and 4th instar larvae were significantly lower than in untreated neighbourhoods. Effective promotion of the Untadita should be able to control mosquito infestation in many washbasins, especially those in frequent use, thus reducing the need for chemical and biological larvicides that may be either more costly or less acceptable to householders.

Aedes↗

Development of an indicator to evaluate the impact, on a community-based Aedes aegypti control intervention, of improved cleaning of water-storage containers by householders.

Householders in a community-based programme to control dengue in El Progreso, Honduras, are being encouraged to improve the cleaning of the water-storage containers in which many of the vectors thrive. The objective of the present study was to develop an indicator of the change occurring in human behaviour. Traditional Aedes aegypti larval indices do not differentiate between containers in which all the immature stages are present and those which hold only first- and second-instar larvae. However, it is not essential to prevent all larval development to limit transmission of pathogens by the adults; if the Ae. aegypti in the containers only manage to develop to young larvae before the containers are cleaned, then control of the vector in these containers will be effective. In field trials, sampling of third- and fourth-instar larvae in washbasins by taking five dips (quick immersions to a standard depth) with a hand-held net was found to be sufficient for estimating the true population size of that same cohort. This sampling method was then included in a large-scale survey of households, conducted for programme monitoring. An index was then developed as a summary measure of the degree of infestation of a washbasin by Ae. aegypti. This index was the sum of four variables assessed in the survey: presence of any immature stages (larvae and/or pupae); presence of pupae; detection of third-fourth-instar larvae in a five-dip sample; and a log-transformation of the number of larvae recovered. Based on this new index, the 884 washbasins encountered in the survey were classified as infestation-free (76.2%), or with low-(6.7%), medium-(14.9%) or high-level (2.2%) infestation. Application of the same procedure to 240 drums encountered in the survey showed that 66.3% were infestation-free and 9.2%, 17.1% and 7.4% had low-, medium- and high-level infestations, respectively. Compared with the traditional indices, this new index should be more sensitive to changes in human behaviour resulting from a control programme exposure than a simple, dichotomous variable (i.e. positive/negative for presence of immature stages). The use of such an index could make the control programme more efficient, allowing the greatest efforts to be targeted at households that have medium-high levels of infestation.

Aedes↗

La Untadita: a procedure for maintaining washbasins and drums free of Aedes aegypti based on modification of existing practices.

Chlorine bleach and detergent are routinely used by householders in El Progreso, Honduras in the process of cleaning washbasins and drums, the two most important larval habitats of Aedes aegypti in the city. The efficacy of these materials in eliminating eggs, larvae, and pupae of Ae. aegypti was assessed under controlled conditions. The promising results obtained led to trials using a combination of chlorine bleach and detergent to apply to the walls of washbasins and drums as a method for eliminating eggs. The bleach maintained its ovicidal properties when mixed with detergent, and the detergent gave the mixture consistency so that it could be applied as a thin film to the walls. This new procedure was named the little dab (Untadita in Spanish) and allows households to direct their efforts against a stage of the mosquito life cycle that has been ignored in the past: the egg.

Aedes↗

Malaria diagnosis by dipstick assay in a Honduran population with coendemic Plasmodium falciparum and Plasmodium vivax.

A Plasmodium lactate dehydrogenase dipstick designed to separately detect P. falciparum and P. vivax malaria was evaluated in two Honduran populations where both species are endemic. The dipstick was compared to thick film microscopy; the polymerase chain reaction (PCR) was used to analyze discordant results. The dipstick had a sensitivity of 100% and a specificity of 95% compared with microscopy in the diagnosis of Plasmodium infections in a hospital population; the mean parasite density was approximately 590/mm3. In a field sample of mostly asymptomatic volunteers, the sensitivity of the dipstick for Plasmodium infection varied with parasite density. Additionally, the sensitivity and specificity of the dipstick was similar to thick film microscopy in the diagnosis of vivax malaria compared with the PCR. The dipstick was unable to detect P. vivax in the presence of P. falciparum because of cross-reactivity in the pan-specific band. Accurate species identification in mixed infections remains a problem in malaria diagnosis.

Clinical Enzyme Tests↗

Emergency contraception: preliminary report of a demonstration and evaluation project.

Kaiser Permanente Southern California and the Pacific Institute for Women's Health began a demonstration and evaluation project on emergency contraceptive pills (ECPs) in the summer of 1996 with the goal of evaluating the feasibility and acceptability of ECPs in a large health maintenance organization and developing institutional templates, provider training and patient education materials that could be used to replicate the project. The ECP program had six components: repackaging of oral contraceptives in an ECP "kit," development of provider education materials, development of patient education materials, in-service training, making ECPs kits available in convenient locations, and development of materials to support replication of the project inside and outside Kaiser Permanente. Although data are still being analyzed, preliminary results are promising. The success of the project within this relatively conservative, but well-established medical care organization provides a model for others. The development of a standard set of educational materials and approaches to implementation should facilitate dispensing ECPs in other settings.

Adult↗

Disordered eating patterns, body image, self-esteem, and physical activity in preadolescent school children.

OBJECTIVE: Eating disorders have been typically defined as an "adolescent problem." As a result of emerging evidence which indicated this health problem to be evident in the prepubescent age range, this study aimed to establish prevalence and factors associated with eating/dieting, physical activity, and body image among a nonclinical, naturalistically-derived sample of preadolescent (aged 10 and 11) school children (n = 61). METHOD: This cohort of children, which represented the entire grade 6 class of a suburban Elementary school, was measured for body image satisfaction [silhouettes], a participation in activity index, a self-worth scale and a measure of eating attitudes & behavior [Eating and Me scale [E & M]]. RESULTS: The longitudinal assessment of body image [3 measures over 9 months] indicated signs of stability of "actual" assessments of body image for males, but marked changes for females who preferred to be ideally "chunkier" in stature over time. Physical activity was only implicated with bulimia for the male sub-group. The E & M scale reported a Cronbach's alpha of .76, with two factors [bulimia; drive for thinness/anorexia] representing 65% of the total variance. Moderate internal validity [r .58] between body dissatisfaction on the E & M scale and the silhouette measure was observed. DISCUSSION: These results demonstrated that body image views and concerns appeared before puberty, that gender differences prevailed with respect to eating/dieting, activity and body image, and that the E & M scale has emerged as a promising research tool. The longitudinal nature of this study of eating disorders also promotes the need for qualitative research methodology and attention to pre-pubertal cognitive/perceptual processes.

Anorexia↗

Laminin alpha 2 is a component of brain capillary basement membrane: reduced expression in dystrophic dy mice.

In the present study we demonstrate low level expression of the laminin alpha 2 chain in brain and localize the alpha 2 protein to the capillary basement membrane. While in peripheral basement membranes the laminin alpha 1 and alpha 2 chains have an almost mutually exclusive distribution, the present results suggest both alpha 1 and alpha 2 in the cerebral capillary basement membrane. Towards elucidating the function of alpha 2 in brain, we have performed ultrastructural analysis of the capillary basement membrane in dystrophic dy mice, which show a 70-90% and > 95% reduction of alpha 2 messenger RNA compared to heterozygous and wild-type mice, respectively, and show a nearly total absence of the alpha 2 protein by immunofluorescence. In contrast to the muscle and Schwann cell basement membrane, where alpha 2 deficiency causes structural basement membrane abnormalities, the present results show that the lack of the alpha 2 subunit in the cerebral capillary basement membrane is not detrimental to its structure. This observation might be explained by the fact that the cerebral capillary basement membrane expresses both alpha chains and therefore exhibits structural redundancy.

Animals↗