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Biomedical subjects

R Walsh

Publications and source records attributed to R Walsh.

At least 55 records · Page 3Linked to original sources
PubMed1997

Axillary lymph nodes: mammographic, pathologic, and clinical correlation.

OBJECTIVE: The purpose of this study was to determine the cause and frequency of axillary abnormalities seen mammographically and to evaluate the imaging characteristics of lymphadenopathy that are associated with malignancy. MATERIALS AND METHODS: Ninety-six axillary abnormalities seen mammographically in 94 patients were retrospectively reviewed and correlated with the clinical diagnoses and pathologic results found in the medical records. For each abnormality, the length, margins, and presence of microcalcifications were noted. Logistic regression was used to determine an association between these findings and status (benign or malignant). RESULTS: Seventy-six of 94 patients had lymphadenopathy. Eighteen of 94 patients had an abnormality other than lymphadenopathy. Because two of these 94 patients had more than one abnormality, a total of 96 abnormalities occurred, 20 of which were due to an abnormality other than lymphadenopathy. Regarding the 76 cases of lymphadenopathy, the most frequent diagnosis was nonspecific benign lymphadenopathy in 29% (n = 22) of cases, followed by metastatic breast cancer in 26% (n = 20) and chronic lymphocytic leukemia or well-differentiated lymphocytic lymphoma in 17% (n = 13). Other causes (n = 21) included collagen vascular disease, lymphomas other than well-differentiated lymphocytic lymphoma, metastatic disease from nonbreast primary site, metastatic disease from unknown primary site, sarcoidosis. HIV-related lymphadenopathy, and reactive lymphadenopathy associated with a breast abscess. An association between length of nonfatty lymph nodes and malignant status was statistically significant at the .001 level. When a length greater than 33 mm was used as a predictor of malignancy, the specificity and sensitivity were 97% and 31%, respectively. We found an association between malignancy and nonfatty lymph nodes with ill-defined or spiculated margins (p = .053). Regarding the 20 abnormalities other than lymphadenopathy, epidermal cysts (n = 7) were most prevalent. CONCLUSION: The most common axillary abnormality revealed on mammography was abnormal lymph nodes. Homogeneously dense (nonfatty) axillary lymph nodes were strongly associated with malignancy when the lymph nodes were longer than 33 mm, had ill-defined or spiculated margins, or contained intranodal microcalcifications. However, our study confirmed that in most cases benign and malignant lymph nodes cannot be distinguished from each other mammographically.

Aged↗
PubMed1996

Palatal trauma: an unusual cause of a parotid sinus.

A case is described of a 3-year-old boy who presented with a seemingly trivial injury to his soft palate, who went on to develop a parotid sinus as a result of a retained foreign body. This is a rare clinical problem and it highlights the difficulty in the clinical assessment of a palatal injury--especially in children. The child had the foreign body removed successfully 5 months after the initial injury and made an uneventful recovery.

Child, Preschool↗
PubMed1996

Training medical students in HIV/AIDS test counselling: results of a randomized trial.

The study assessed the effectiveness of a programme aimed at increasing medical students' skills in counselling patients presenting for HIV testing/AIDS information. Senior medical students were randomly assigned to receive a short course in pre- and post-test counselling, or to a control group which received the usual curriculum. The students' performance in counselling simulated patients was videotaped at baseline and after 3 months. A subsample was also assessed at 12 months. Students receiving the programme showed significantly greater improvement in pre- and post-test counselling skills over 3 months than did the controls. For the sub-sample continuing to 12 months, a significant effect over time was found; however, there was no significant difference between the groups. This may have been influenced by the small sample sizes used for the 12-month assessment. General interactional skills improved for the over-all sample over 3 and 12 months, but again there were no significant differences between groups. Those exposed to the programme did not show significantly greater changes in either knowledge or attitude scores over either time frame, compared with controls. When taught in addition to the usual undergraduate curriculum at Newcastle University, this short interactional skills course significantly enhanced students' ability to provide pre- or post-test counselling for HIV/AIDS.

AIDS Serodiagnosis↗
PubMed1996

Complex radial folds versus subtle signs of intracapsular rupture of breast implants: MR findings with surgical correlation.

Detection of intracapsular rupture of silicone breast prostheses using MR imaging is often performed by identifying the "linguine sign" [1]. The linguine sign is easily differentiated from simple radial folds that are seen in intact implants. However, more subtle signs of intracapsular rupture, including undulating subcapsular lines and the "teardrop sign," are less often recognized [2-5] and may prove difficult for the less experienced radiologist to differentiate from complex radial folds of intact implants. In this essay, we illustrate the MR imaging findings of complex radial folds in intact implants and compare them with findings of incomplete shell collapse in ruptured implants in a surgically confirmed series of explanted silicone breast prostheses.

Breast↗
PubMed1996

A sheet-like form of alpha-crystallin.

Complexes containing alpha-crystallin were isolated from crosslinked lens extract using an affinity column constructed with monoclonal antibodies specific for alpha-crystallin. The affinity-purified protein was compared with alpha-crystallins before and after crosslinking. Electron microscopy revealed sheet-like structures in the cross-linked protein from the lens extract compared with spherical structures for the others. Studies on the amino acid composition, tryptophan microenvironments and the interaction with a monoclonal antibody revealed that the complexes consist almost entirely of alpha-crystallin. These results indicate that under certain conditions, alpha-crystallin subunits can adopt a sheet-like form.

Amino Acids↗
PubMed1995

Colitis reduces short-circuit current response to inflammatory mediators in rat colonic mucosa.

Inflammatory mediators may contribute to the diarrhea associated with colitis. Although the secretory action of such mediators is reported in normal tissue, there is little information regarding their effects on inflamed tissue. We examined the short-circuit current response (Isc) to these mediators, in mitomycin-C (MC)-induced colitis, a model with histological similarities to colitis in man. Rats were injected once with MC (3.25 mg/kg, intraperitoneally) or vehicle. The colons were removed three and seven days later and mounted, devoid of muscularis, in Ussing chambers for measurement of Isc, potential difference (PD), and resistance (Rt). MC-treated rats had diarrhea after three days, and microscopic studies revealed colonic inflammation. There were no significant differences in Rt, PD, and Isc between control and MC-treated tissues at three and seven days. Maximal increases in Isc to bradykinin, prostaglandin E1, carbachol, substance P, and serotonin were depressed at three and/or seven days after MC. The Isc response to theophylline was not affected. Theophylline activates secretion through an intracellular mechanism; the other agonists act by interaction with epithelial cell membranes. Therefore, the mechanism for the decreased Isc may result from uncoupling of receptors to second-messenger systems or desensitization of receptor-linked secretory mechanisms.

Alprostadil↗
PubMed1995

Smoking in hotels: prevalence, and opinions about restrictions.

Exposure to high levels of environmental tobacco smoke can occur in hotels. Controversy exists about smoking regulation on licensed premises. This survey of 138 people attending one of three Newcastle hotels during 1993 found that 57 per cent of respondents were nonsmokers. Fifty-eight per cent (95 per cent confidence interval (CI) 50 to 66 per cent) of respondents in these hotels believed their health was being adversely affected by other people's smoke in the hotel. Seventy per cent (CI 62 to 78 per cent), including half the smokers, were in favour of restriction of smoking in the hotels. Most preferred the establishment of smoke-free areas to the introduction of total smoking bans in hotels. The failure of hotels to regulate smoking suggests that a legislative approach is required. The case for legislation would be strengthened by a larger study elsewhere in Australia.

Adult↗
PubMed1995

Papillary carcinoma of the breast: imaging findings.

Papillary carcinoma is a rare malignant tumor of the breast for which the survival rate is better than for most breast carcinomas. Histologically, invasive and in situ forms occur; the in situ form can extend throughout a ductal system (intraductal) or can be confined within a cystic structure (intracystic). Invasive papillary carcinoma can spread from either of the in situ forms but spreads more commonly from the intracystic type. Many reports in the literature have failed to differentiate invasive from in situ papillary carcinomas; similarly, the different mammographic patterns of the two in situ forms of these lesions have not been delineated clearly. Our review of 16 new cases of papillary carcinoma showed a frequent correlation between the histologic types and the mammographic appearance. The intraductal in situ form usually was characterized by clustered microcalcifications. The intracystic in situ type was associated with well-circumscribed masses on mammograms; these masses often were complex on sonograms. The purpose of this essay is to illustrate the mammographic and sonographic features of the histologic varieties of papillary carcinoma. Color Doppler sonograms and MR images of intracystic and invasive tumors also are included.

Aged↗
PubMed1994

POST-EXERCISE LACTATE PRODUCTION AND METABOLISM IN THREE SPECIES OF AQUATIC AND TERRESTRIAL DECAPOD CRUSTACEANS

Aquatic and terrestrial crustaceans are dependent on both aerobic and anaerobic metabolism for energy production during exercise. Anaerobic energy production is marked by an accumulation of lactate in both muscle tissue and haemolymph, but the metabolic fate of lactate is not clear. Lactate recycling via gluconeogenesis and the potential role of carbonic anhydrase (CA) in supplying bicarbonate for the carboxylation of pyruvate were investigated in three species of decapod crustaceans: Callinectes sapidus (aquatic), Cardisoma guanhumi (semi-terrestrial) and Gecarcinus lateralis (terrestrial). CA activity was found in mitochondria and cytoplasmic fractions of gill, hepatopancreas and muscle of all three species. Significant activities of key enzymes of gluconeogenesis (e.g. pyruvate carboxylase, phosphoenolpyruvate carboxykinase and fructose bisphosphatase), however, could not be detected. Exercise to exhaustion produced a species-specific pattern of accumulation and clearance of lactate in tissue and haemolymph, indicating a differential degree of reliance on anaerobic energy production. Treatment with acetazolamide, a CA inhibitor, did not significantly alter the pattern of lactate dynamics in animals given repeated bouts of exhaustive exercise interspersed with periods of recovery. Injection of [U-14C]lactate resulted in the appearance of label in both muscle glycogen and excreted carbon dioxide, suggesting multiple metabolic fates for lactate. Lactate turnover rates for G. lateralis were similar to those reported for fish. In these animals, gluconeogenesis possibly proceeds via the reversal of pyruvate kinase, or via the typical Cori cycle but so slowly that the uncatalysed supply of bicarbonate is sufficient to keep pace with the low activities of pyruvate carboxylase and the subsequent low rates of pyruvate carboxylation.

Journal Article↗
PubMed1993

Inflammatory mediator changes in cotton-top tamarins (CTT) after SC-41930 anti-colitic therapy.

Use of the CTT model provides insight into the inflammatory mediator contribution in the pathogenesis of idiopathic colitis. To evaluate anti-colitic efficacy, the leukotriene B4 receptor antagonist and anti-inflammatory agent, SC-41930, was administered (10 mg/kg BW by gavage BID) for 8 weeks to CTTs with histologically confirmed persistent and defined active colitis. The inflammatory mediators LTB4, PGE2, TXB2, and PAF were assayed in colonic dialysate that was collected after 1 1/2 h from four CTTs pre-, mid-, and post-treatment, frozen at -70 degrees C, and analyzed by RIA after HPLC purification. LTB4 levels were lower at mid- and post-treatment and had little inter-animal variation post-treatment. PGE2 and PAF levels were elevated during SC-41930 treatment, but there was a trend towards lower thromboxane B2 levels. Reduced LTB4 (PMN degranulation and chemotaxis) and increased PGE2 (mucosal-protective effect) may, in part, explain the observed efficacy of SC-41930 in active tamarin colitis.

Animals↗
PubMed1992

Drug use in Australia: a community prevalence study.

OBJECTIVE: To estimate the prevalence of drug use in a representative Australian community. DESIGN: Using a Census district sampling framework supplied by the Australian Bureau of Statistics, we randomly selected dwellings for our survey. A household was defined as all those people living permanently at the postal address. All eligible members of each household, 15 years and older, were asked to participate. SETTING: The data were collected in the context of a large scale general population survey of health practices and attitudes, conducted in the Greater Newcastle area of New South Wales, during 1987 and 1988. PARTICIPANTS: Seventy-two per cent of eligible individuals approached (2623) agreed to participate in the survey. MAIN OUTCOME MEASURES: Participants were asked about their use of a number of drug types: medically prescribed drugs, non-prescription drugs, tobacco, alcohol and illicit drugs. For alcohol, only the results for use at a hazardous level according to the National Health and Medical Research Council guidelines are reported here. RESULTS: Seventy-eight per cent (95% confidence interval, 76%-80%) of the community sample reported having recently consumed at least one of these drug types. There were significant age and sex differences in drug use. A greater proportion of women and the older age groups (over 45 years) reported the use of both non-prescription and prescription medications than did men and the younger age groups. Conversely, a significantly greater proportion of men and the younger age groups reported the use of social and illicit drugs. CONCLUSION: The importance of regular, representative, methodologically comparable community studies of drug use is stressed, particularly in view of the inadequacy of the current routine sources of epidemiological data on drug use.

Adolescent↗
PubMed1992

A comparative study of calcium sodium alginate (Kaltostat) and bismuth tribromophenate (Xeroform) packing in the management of epistaxis.

A prospective study was undertaken to compare the efficacy of calcium sodium alginate fibre (Kaltostat) to petrolatum gauze impregnated with bismuth tribromophenate (Xeroform) for the control of epistaxes that require hospital admission. Forty patients presenting with severe epistaxis requring hospital admission were treated with either Kaltostat or Xeroform nasal packs. Allocation to either treatment group was made randomly. The composition of each group in terms of age, sex distribution, aetiology of epistaxis and severity of bleed was not significantly different. There was no significant difference in the efficacy or patient acceptability of either therapeutic agent. It is concluded that calcium sodium alginate fibre should be considered as an acceptable alternative to traditional gauze packing.

Adolescent↗