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Biomedical subjects

A Patel

Publications and source records attributed to A Patel.

At least 577 records · Page 32Linked to original sources
PubMedDate not supplied

Laparoscopic approaches to transitional cell carcinomas of the upper urinary tract.

Traditionally transitional cell tumors of the upper urinary tract are treated by nephroureterectomy. In circumstances where low functional renal reserve necessitates renal parenchymal preservation, endoscopic or percutaneous treatment may be an option for low grade and stage lesions. In this article, the role of laparoscopic surgery as an alternative modality to open surgery is discussed. Techniques of laparoscopic nephroureterctomy are described and different approaches (transperitoneal, retroperitoneal, and gasless hand-assisted) are contrasted. The limitations imposed on laparoscopic treatment by the requirement of adherence to oncological principles of tumor containment and excision of the intramural ureter, are outlined. Laparoscopic nephroureterectomy, although technically demanding, has been shown to be a feasible procedure. Benefits of the laparoscopic approach include shortened hospital stay and early return to daily activities. It is unclear at this time whether these immediate advantages over open surgery will yield comparatively efficacious long term outcomes.

Activities of Daily Living↗
PubMedDate not supplied

Spontaneous regression of human melanoma/nonmelanoma skin cancer: association with infiltrating CD4+ T cells.

Spontaneous regression occurs in some human malignant melanomas and basal cell carcinomas (BCCs). We have compared the cellular infiltrate in regressing and nonregressing tumors in order to analyze the mechanism by which regression occurs. Regressing primary melanomas and BCCs were infiltrated with a larger number of CD4+, but not CD8+, T lymphocytes than were seen in nonregressing tumors. The number of interleukin 2 receptor-positive (early activation marker) but not transferrin receptor-positive (intermediate activation marker) T cells was increased, indicating that the infiltrating T cells were activated. Large numbers of Langerhans cells, macrophages, and other class II major histocompatibility complex (MHC)-expressing cells were present but were not increased in the regressing tumors. There were no detectable B lymphocytes, and the regressing tumor cells displayed levels of HLA-DR expression similar to those of the nonregressing tumors. Comparison of squamous cell carcinoma (SCCs) with keratoacanthomas (KAs), which are likely to be a spontaneously regressing form of SCC, also showed increased infiltration of activated CD4+, but not CD8+, T cells within the KA. A murine ultraviolet (UV)-induced squamous tumor that spontaneously regresses when transplanted into immunocompetent syngeneic mice was also infiltrated with increased numbers of activated CD4+, but not CD8+, T cells prior to and during rejection. These results indicate that spontaneous regression of human skin tumors is likely to be immunologically mediated, and that CD4+ T lymphocytes seem to mediate this regression.

Animals↗
PubMedDate not supplied

Clinicopathologic features of Chandler's syndrome.

The clinicopathologic features of Chandler's syndrome are elucidated based on a study of nine patients. Keratoplasty, trabeculectomy and/or iris specimens were studied by light, electron and, in six cases, specular microscopy. The prominent pathologic features were abnormalities of the endothelially-derived cells lining the posterior corneal surface, the inner surface of the trabecular meshwork, and the anterior iris surface. In all four corneal buttons, the endothelium was diffusely attenuated and focally absent, and posterior collagen layers were present. Extension of the endothelial cell layer and Descemet's membrane deposition over the trabecular meshwork were observed in two trabeculectomy specimens, and similar proliferation onto the anterior surface of the iris was evident in four iris specimens. Other abnormalities of the endothelial cells included increased intracytoplasmic filaments. These pathologic alterations are consistent with the concept of Chandler's syndrome as representing one variant of the iridocorneal endothelial (ICE) syndrome. Interestingly, although both endothelial proliferative and degenerative responses can be observed in Chandler's syndrome, their occurrence within the same eye is apparently not simultaneous.

Adult↗
PubMedDate not supplied

Dysphoric and depressive symptoms in chronic schizophrenia.

This study suggests that depressive symptoms are less common in severe, chronic, schizophrenic inpatients than would be predicted if these symptoms were manifestations of negative symptoms or drug-induced parkinsonism. The findings further suggest that depressive symptoms in such patients are independent phenomena which conform to a depressive syndrome. This depression does not represent a misidentification of the negative symptoms affective flattening and alogia, as measured by the SANS, or parkinsonism or akathisia. The study findings fail to support the view that long-term depot antipsychotic medication plays an important role in the genesis of depression and dysphoria in chronic schizophrenic patients. Depressive symptoms were found to occur as frequently, and dysphoria more frequently, in schizophrenic patients in the year after drug withdrawal compared with patients continuing on maintenance drug treatment for the same period.

Administration, Oral↗
PubMedDate not supplied

Chromosome 7q35 and susceptibility to diabetic microvascular complications.

Aldose reductase (ALR2), the first enzyme of the polyol pathway, may plan an important role in the pathogenesis of diabetic microvascular complications. The gene coding for ALR2 has been localized to chromosome 7q35. Using an ALR2 probe in conjunction with the restriction endonuclease Bam-HI, we have investigated the ALR2 locus of 128 patients with type I diabetes. A significant decrease in the frequency of the 8.2 kilobase (kb) Bam-HI ALR2 genotype and 8.2 kb allele was found in patients with nephropathy (nephropaths) compared to those with retinopathy alone (retinopaths) (p < 0.05 and 0.25, respectively). We have previously shown that an RFLP of the T-cell antigen receptor constant beta-chain (TCRBC) locus, which is also localized to chromosome 7q35, is strongly associated with susceptibility to microvascular complications. The 128 patients were genotyped using the restriction endonuclease Bgl-II and a TCRBC probe. The 10/9.2-8.2 kb TCRBC-ALR2 genotype was significantly decreased in the nephropaths compared to the retinopaths (13.7% versus 43.6%, chi 2 = 10.1, p < 0.0025). The 10/9.2 and 9.2/9.2 kb TCRBC-ALR2 haplotypes were increased in the nephropaths compared to the retinopaths (32.5% versus 8.9% chi 2 = 10.9, p < 0.001). These results suggest that chromosome 7q35 harbors a gene(s) that is involved in the pathogenesis of microvascular complications. Interestingly, the gene coding for endothelial nitric oxide synthase has recently been localized to the same chromosomal region as ALR2.

Adolescent↗
PubMedDate not supplied

Diabetes in general practice: Tongans in Tonga and South Auckland.

The aim of this study was to compare the management and treatment outcomes of Tongan diabetic patients in Tonga and South Auckland, New Zealand. This was achieved by comparison of Tongan diabetic patients within clinical audits from a general practice in Tonga (n = 124) with those from participating general practices in South Auckland (n = 168). Our results indicate that some measures of diabetes care and outcomes were similar or even better in Tonga, while some interventions were not available in Tonga. Control of weight, glucose, blood pressure and cholesterol remained difficult in both areas. Severe diabetic foot damage was more common among Tongan patients in Tonga (6.5% vs 1.8%, P < 0.05). This international comparison shows that Tongans in both Tonga and New Zealand remain at high-risk of complications independent of the health system under which care is being delivered. While barriers to implementation may differ in the two settings, improvements in the co-ordination of care are likely to be of benefit in both settings.

Diabetes Complications↗
PubMedDate not supplied

Ethnic differences in the growth of lung function in children: a cross-sectional study in inner-city Nottingham.

Measurements of ventilatory capacity have been made in 664 healthy school-children (ages 5-16 years) of European, Afrocaribbean and Indian stock living in the same environment in inner-city Nottingham: 100%, 95% and 80% of these three groups respectively had been born in the UK. The ventilatory capacity data have been analyzed by logarithmic regressions on stature. For forced vital capacity (FVC) and forced expiratory volume (FEV1) a large difference between European and Indian children was found, amounting to 13% at a given stature. The Afrocaribbean children have values similar to those of the Indians. There were no material ethnic differences for peak expiratory flow rate or for FEV1/FVC(%). The differences in FVC and FEV1 appear to be attributable to constitutional rather than environmental influences.

Adolescent↗
PubMedDate not supplied

Effects of walking on ventilatory and cardiac function in intact and cardiac-impaired lobsters.

Decapod crustaceans with normal heart function respond to the increased oxygen delivery requirements during walking with a step increase in heart and ventilation rate. In American lobsters, ventilation rate increased by the same amount during exercise at two walking speeds (2.4 and 8 m min(-1)); however, ventilation volume was significantly greater at the fastest walking speed (280 mL min(-1)) compared to animals at rest or walking at the slower speed (180 mL min(-1)). The heart responded in a similar manner to locomotion. Heart rate was elevated to the same level at the two different walking speeds, but cardiac stroke volume was greater, implying increased cardiac output, at the faster walking speed. The communication and compensation between the cardiac and ventilatory systems was revealed when the function of one was impaired. Ventilatory rate was significantly elevated when cardiac output was impaired by sectioning two of the alary ligaments and/or the regulatory nerves to the heart. When cardiac output was more severely impaired, ventilation rate was greater. Despite ventilatory compensation, anaerobic metabolism made a greater contribution to energy production with impaired heart function. Hemolymph lactate concentration was three to five times greater in impaired animals than controls. It is known that the ventilatory and cardiac systems of lobsters are coregulated. These data demonstrate that the performance of one system can respond to compensate for impaired function in the other.

Animals↗
PubMedDate not supplied

Pars plana vitrectomy for aphakic cystoid macular edema.

The authors used a combined limbal and pars plana vitrectomy approach to treat 17 consecutive eyes (16 patients) with chronic aphakic cystoid macular edema associated with vitreous incarceration in the cataract wound. Criteria for surgery included: decreased visual acuity to 20/50 or worse; cystoid macular edema confirmed by fluorescein angiography; persistent edema of 6 months or longer; and visible vitreous incarceration in the limbal wound. The vitreous was successfully removed from the limbal wound in 16 of 17 eyes. Postoperatively, vision improved by two lines or more in 11 eyes (65%). The surgical technique is described.

Adult↗
PubMedDate not supplied

A study of out-of-hours telephone advice from an A&E department.

A prospective analysis of telephone calls to an accident and emergency (A&E) department during weekday evenings/nights and weekends was undertaken over a 3-month period. A telephone consultation record (TCR) proforma was developed to record information about each call for advice. The volume of calls, characteristics of callers and patients, nature of presented problems, and advice given were analysed. An average of 9.3 calls were documented during each weekend 24-hour period, and 3.3 calls during each weekday evening/night. Junior nurses took 93% of calls. Advice was sought for a broad range of problems, of which only 11% were musculoskeletal conditions or injuries. Twenty-six per cent of patients were advised to attend A&E, 35% were given self-care advice, and the remainder were advised to contact or see their GP. There is considerable potential to develop a nurse-provided telephone advice service, but the need for staff training and guidelines has to be addressed.

Adolescent↗