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Biomedical subjects

S Shah

Publications and source records attributed to S Shah.

At least 469 records · Page 26Linked to original sources

Roxatidine versus ranitidine in the treatment of patients with duodenal ulcer: a randomized, double-masked, multicenter study.

The comparative efficacy of roxatidine and ranitidine in the treatment of patients with acute duodenal ulcer was assessed at 4 and 6 weeks in this multicenter study. Ninety-four of 192 patients were given roxatidine in a single nightly dose of 150 mg, and 98 patients were given ranitidine in a single nightly dose of 300 mg. All the patients had endoscopically proven duodenal ulcer. Of the 171 assessable patients, ulcers were healed in 88% of the roxatidine group (73 of 83) and in 84% of the ranitidine group (74 of 88). No serious adverse events were reported in either group. We conclude that roxatidine 150 mg once daily is as effective and safe for the treatment of acute duodenal ulcer as ranitidine 300 mg once daily.

Administration, Oral↗

The effect of ethanol drinking on opioid analgesia and receptors in mice.

Recent studies suggest substantial interactions between opioids and ethanol (EtOH). Both in vivo and in vitro experiments indicate that EtOH can regulate opioid systems and that opioids can modify EtOH consumption. In the present studies, we examined if EtOH consumption altered opioid receptors and the potency of opioid analgesics. Mice were given unlimited access to 6-7% EtOH alone for 7 days or were allowed to drink increasing concentrations (3-6%) of EtOH over 13-14 days. Controls had access to water. The EtOH groups drank significantly less volume than controls, although there were no significant differences in body weight or baseline nociception. The analgesic (tail flick) potency of SC morphine was decreased by approximately 1.6-2.0-fold in EtOH-treated mice. A single acute dose of EtOH (1 g/kg) that produced blood alcohol levels in excess of that for 7 day exposure to EtOH, did not change morphine's analgesic ED50, suggesting that chronic exposure to EtOH was necessary for the reduction in potency. The change in morphine potency was not due to pharmacokinetic differences because EtOH consumption did not modify the concentration of morphine in brain and spinal cord. The analgesic potency of a delta-opioid receptor agonist (ICV DSLET) was also decreased by approximately 2-fold. Saturation binding studies indicated no changes in the density or affinity of brain and spinal cord delta-opioid ([3H]DPDPE, [3H]DSLET, [3H]DeltorphinII) and mu-opioid ([3H]DAMGO) receptors. Similarly, there was no significant effect of EtOH on delta-opioid receptor mRNA in either brain or spinal cord preparations. Taken together, these data suggest that EtOH consumption decreases the analgesic potency of opioids in mice through a mechanism that is unrelated to pharmacokinetics or opioid receptor changes in brain and cord.

Alcohol Drinking↗

Separate nuclear import pathways converge on the nucleoporin Nup153 and can be dissected with dominant-negative inhibitors.

BACKGROUND: Proteins generally enter or exit the nucleus as cargo of one of a small family of import and export receptors. These receptors bear distant homology to importin beta, a subunit of the receptor for proteins with classical nuclear localisation sequences (NLSs). To understand the mechanism of nuclear transport, the next question involves identifying the nuclear pore proteins that interact with the different transport receptors as they dock at the pore and translocate through it. RESULTS: Two pathways of nuclear import were found to intersect at a single nucleoporin, Nup153, localized on the intranuclear side of the nuclear pore. Nup153 contains separate binding sites for importin alpha/beta, which mediates classical NLS import, and for transportin, which mediates import of different nuclear proteins. Strikingly, a Nup153 fragment containing the importin beta binding site acted as a dominant-negative inhibitor of NLS import, with no effect on transportin-mediated import. Conversely, a Nup153 fragment containing the transportin binding site acted as a strong dominant-negative inhibitor of transportin import, with no effect on classical NLS import. The interaction of transportin with Nup153 could be disrupted by a non-hydrolyzable form of GTP or by a GTPase-deficient mutant of Ran, and was not observed if transportin carried cargo. Neither Nup153 fragment affected binding of the export receptor Crm1 at the nuclear rim. CONCLUSIONS: Two nuclear import pathways, mediated by importin beta and transportin, converge on a single nucleoporin, Nup153. Dominant-negative fragments of Nup153 can now be used to distinguish different nuclear import pathways and, potentially, to dissect nuclear export.

Animals↗

Surgical resection improves survival in the treatment of early gastric lymphomas.

Gastric lymphomas are a relatively rare form of malignancy and controversy about their optimum treatment still exists. To date, there have been no studies directly comparing results of medical therapy alone versus a combination of surgery plus medical therapy. We reviewed our experience in the three teaching hospitals of the University of Massachusetts Medical School to determine the role of surgery in the management of early gastric lymphoma. Statistics were evaluated by means of chi-square, log-rank, and Kaplan-Meier curve analysis where appropriate. Using tumor registry data, 39 patients were treated for early disease at our medical school from 1980 to 1998. Patients treated with surgery plus chemotherapy and radiation had a 90% 5-year survival compared to patients who received chemotherapy and radiation alone (55% 5-year survival; P <0.01). When we compared all patients on an intention-to-treat basis (patients preoperatively thought to have early-stage disease), there was still a significant survival benefit with the addition of surgery to their management. Because this is an uncommon disease, there are no large prospective studies examining treatment. Based on our retrospective experience, surgical resection should be considered an important adjunct in the treatment of gastric lymphomas in early-stage disease.

Adult↗

Leptomeningeal involvement in chronic lymphocytic leukemia.

PURPOSE: This review and case report address the rare complication of leptomeningeal involvement in patients with chronic lymphocytic leukemia. OVERVIEW: Chronic lymphocytic leukemia is the most common form of leukemia, with more than 200,000 cases reported in the past 20 years. An uncommon complication of the disorder is central nervous system invasion. To date, only 21 cases have been reported, and their presenting symptoms have been heterogeneous and often nonspecific, including headache, cranial nerve abnormalities, confusion, ataxia, nausea, vomiting, and fever. The diagnosis is confirmed by the presence of a clonal population of lymphocytes in the cerebrospinal fluid. Treatment is either intrathecal or intraventricular chemotherapy with adjuvant radiation therapy or radiation alone. Prognosis is improved by prompt and aggressive therapy. In this case report, a 61-year-old man developed severe ataxia, vertigo, and occipital headaches 4 weeks after diagnosis with otherwise asymptomatic chronic lymphocytic leukemia. After treatment with both radiation to the head and neck and intrathecal methotrexate the patient achieved complete symptom resolution. Thus far, no additional systemic cytotoxic chemotherapy has been necessary. CLINICAL IMPLICATIONS: Because central nervous system invasion is uncommon in chronic lymphocytic leukemia, it may go undiagnosed and under-reported. Providers of patients with this disease need to be aware of possible central nervous system invasion when patients present with cranial nerve signs or symptoms and/or nonspecific neurologic manifestations. Early identification and prompt central nervous system-directed chemotherapy can affect morbidity and quality of life positively.

Antimetabolites, Antineoplastic↗

Duplication of pituitary gland.

We present a case of duplication of the pituitary gland with associated clefts of the hard palate and body of the sphenoid and a midline palatine dermoid. This is an extremely rare malformation with only six previous case reports in the literature. Imaging findings are discussed and literature reviewed for possible morphogenesis, including its association with partial twinning and midline cleft face syndrome.

Abnormalities, Multiple↗

Phase I therapy trials in children with cancer.

PURPOSE: This study examined the response and toxicity rates of antineoplastic drugs evaluated in phase I clinical trials in children to identify trends in response and toxicity over time. PATIENTS AND METHODS: Full length, peer-reviewed articles describing the results of single agent phase I therapy trials in children younger than 21 years with cancer were reviewed. Tumor-specific response data and doses of drugs that resulted in objective responses were noted. Deaths that occurred on study caused by drug toxicity, progressive disease (PD), or complications of marrow aplasia were identified, along with drug doses that resulted in toxic death. Temporal trends in response rates, toxicity, and number of patients entered in trials were examined. RESULTS: A total of 1,606 patients with cancer were enrolled in 56 single-agent pediatric phase I therapy trials published between 1978 and 1996. Of these, 1,257 were evaluated for response by tumor type. The overall objective response rate was 7.9%. Response rates were highest for patients with neuroblastoma (17.7%) and acute myelogenous leukemia (11.6%). Patients with osteosarcoma and rhabdomyosarcoma had response rates of < 3%. Sixty percent of responses in patients with solid tumors occurred at 81 to 100% of the maximum tolerated dose (MTD), although 42% of responses in patients with leukemia occurred at > 100% of the MTD. Death on study was noted in 7.0% of all patients entered in trials. Only 0.7% of patients experienced a death related to drug toxicity. PD accounted for the death of 5.6% of study participants. A trend of increasing response rate despite smaller trial size was noted over the last 7 years of this period. CONCLUSION: Phase I trials in children with cancer represent a safe mechanism to determine the MTD, toxicity profile, and pharmacokinetics of new agents for use in children with cancer.

Adolescent↗

Silver sulphadiazine: a comprehensive in vitro reassessment.

The antimicrobial activity of silver sulphadiazine has been determined agonist 409 strains from 12 different genera. MICs were usually in the range 16-64 micrograms/ml. Multi-resistant species, such as methicillin-resistant Staphylococcus aureus and Acinetobacter spp., were uniformly sensitive. MICs always exceeded the reported aqueous solubility of silver sulphadiazine. No resistant strains were found, and there was no correlation between MIC of silver sulphadiazine and resistance to sulphonamides. Time-kill experiments showed that sulphonamide-resistant S. aureus (but not Staphylococcus epidermidis) were killed significantly more slowly than were sulphonamide-sensitive strains.

Acinetobacter↗

Benchmarking best practice for external ventricular drainage.

Sharing of best practice and use of all available evidence is important in developing effective clinical guidelines for nursing practice. This can be achieved through benchmarking. Sharing of good practice and achieving consensus guidelines can avoid repetition of effort by nurses engaged in similar fields of practice. The Pan London Neuroscience Practice Development Forum was established in 1998 to share best practice within the field of neuroscience nursing across London. The Pan London Forum has now achieved consensus and developed evidence-based clinical guidelines for the management of external ventricular drainage. Within the scope of this article, the principles of external ventricular drainage will be highlighted, before identifying the evidence base for nursing management of patients. Approaches for troubleshooting common problems will also be discussed and the benchmarked clinical guidelines will be presented.

Benchmarking↗

Differences in keratocyte apoptosis following transepithelial and laser-scrape photorefractive keratectomy in rabbits.

BACKGROUND: Anterior stromal keratocyte cells undergo programmed cell death (apoptosis) in response to corneal epithelial injury. Keratocyte apoptosis may be an initiator of the corneal wound healing response that includes keratocyte proliferation and activation, as well as changes to the overlying epithelium, occurring following refractive surgical procedures such as photorefractive keratectomy (PRK). This study compared the effect of laser-scrape and transepithelial PRK on keratocyte apoptosis. METHODS: Photorefractive keratectomy was performed in both eyes of 10 New Zealand white rabbits using the Summit Apex excimer laser. Surgery was performed using transepithelial PRK in one eye and laser-scrape PRK in the other. The central cornea was analyzed at 4 hours after surgery using a quantitative TUNEL assay that detects fragmented DNA characteristic of apoptosis. Hepatocyte growth factor (HGF) production by keratocytes was detected by immunocytochemistry. RESULTS: Average apoptotic cells per 400X microscopic field determined by 2 independent masked observers were 0.9 +/- 0.5 (scanning electron microscopy) and 0.2 +/- 0.2 in the transepithelial PRK group compared with 5.1 +/- 2.9 and 4.1 +/- 3.2 in the laser-scrape group. The difference between the two groups was statistically significant for both observers (P < .05, ANOVA). HGF was detected within keratocytes throughout the corneal stroma. Less HGF was detected in the anterior stroma in the laser-scrape group at 4 hours after surgery, consistent with more anterior keratocyte apoptosis in this group. CONCLUSIONS: Transepithelial PRK induced less anterior keratocyte apoptosis in rabbits than laser-scrape PRK. This suggests that transepithelial PRK could be useful in preventing or minimizing refractive regression and subepithelial scarring.

Animals↗

Factors that influence patient choice of contact lens or photorefractive keratectomy.

OBJECTIVE: To explore characteristics of patients and factors that influence their decision in selecting photorefractive keratectomy (PRK) and contact lenses. METHODS: A questionnaire was presented to 255 PRK and 240 contact lens patients, covering patient demographics, refraction, reasons for choosing PRK or contact lens, and advice from clinicians or friends/relatives. RESULTS: Mean patient age was 37 years for PRK and 26 years for contact lens (P < .0001). The magnitude of the mean spherical equivalent refraction in the better eye was 4.14 D for PRK and 3.26 D for contact lens. Advertising influenced 36% (n = 92) of PRK compared to 17% (n = 41) of contact lens patients. In the PRK group, 52% (n = 133) opted for PRK based on cost; in the contact lens group the cost of PRK was thought to be high by 68% (n = 163). Eighty-four percent (n = 214) of the PRK group were contact lens wearers; of these, 32% (n = 68) were intolerant to contact lenses and 13% (n = 28) were intolerant to lens care solutions. Fifty-six percent (n = 134) of the contact lens group were concerned about the long-term effects of PRK and 49% (n = 118) were afraid to undergo a surgical procedure. CONCLUSIONS: PRK patients were significantly older but had only marginally higher refractive error than contact lens patients. Many patients appeared to discontinue contact lens use due to tolerance problems.

Adult↗

Effect of an elliptical optical zone on outcome of photoastigmatic refractive keratectomy.

BACKGROUND: This study presents the effect of an elliptical optical zone on the accuracy of correction of astigmatism in patients undergoing photorefractive astigmatic keratectomy (PARK) for myopic astigmatism. METHODS: We reviewed a consecutive case series of 102 eyes that underwent PARK with a Nidek EC-5000 excimer laser by a single surgeon. Group A consisted of 50 eyes treated using a circular optical zone of 6.5 mm x 6.5 mm with a 7.5-mm x 7.5-mm transition zone. Group B consisted of 52 eyes treated using an elliptical optical zone of 5.5 mm x 6.5 mm with a 6.5-mm x 7.5-mm transition zone. Refraction was measured preoperatively and postoperatively, and vector analysis was used to study the change in astigmatism induced by surgery. RESULTS: Mean correction index improved from 75% in Group A to 100% in Group B. Mean angle of error was reduced from 15.8 degrees in Group A to 7.5 degrees in Group B. Hyperopic shift was reduced from +0.70 D in Group A to +0.20 D in Group B. CONCLUSIONS: Excimer laser photorefractive astigmatic keratectomy using an elliptical optical zone improved the correction index for astigmatic change and reduced the mean angle of error. An elliptical optical zone is more effective than the circular optical zone for the treatment of astigmatism in patients with compound myopic astigmatism.

Astigmatism↗

Arcuate transverse keratotomy remains a useful adjunct to correct astigmatism in conjunction with photorefractive keratectomy.

PURPOSE: To retrospectively evaluate the effectiveness of paired, arcuate transverse keratotomy (Arc-T) performed prior to or after photorefractive keratectomy (PRK) to correct low to moderate amounts of natural or laser-induced astigmatism. METHODS: Spherical PRK was performed in 730 eyes for myopia of -1.00 to -7.00 D. PRK with arcuate transverse keratotomy was performed in 150 of these eyes; we studied 123 eyes that did not have PRK enhancement. Arc-T was performed prior to PRK in all 37 study eyes with astigmatism of 1.50 D or more at the preoperative examination. Arc-T keratotomy was performed after PRK in 86 study eyes for residual astigmatism of +0.75 D or more and uncorrected visual acuity of 20/30 or worse. RESULTS: Arc-T before PRK group: PRK was performed at a mean 1.0 +/- 1.5 months after Arc-T. Mean astigmatism decreased from +2.40 +/- 0.6 D (range, 1.00 to 4.00 D) before Arc-T to 0.60 +/- 0.60 D (range, 0 to 2.25 D) after Arc-T (P < .0001). Net change in astigmatism was 1.80 +/- 0.60 D (range, 0.80 to 2.80 D) and mean reduction was 75%. Spherical equivalent refraction changed from -4.10 +/- 1.90 D (range, -0.25 to -8.10 D) to -4.40 +/- 1.80 D after Arc-T (P = .002). Mean change in spherical equivalent refraction after Arc-T was -0.30 +/- 0.50 D (range, -1.10 to +0.40 D). Arc-T after PRK group: Arc-T was performed at a mean 3.5 +/- 1.9 months after PRK. Six months after Arc-T, astigmatism was decreased from +1.50 +/- 0.60 D to 0.40 +/- 0.40 D (P = .04). Net change in astigmatism at 6 months was 1.10 +/- 0.60 D and mean reduction was 74%. Vector change in astigmatism magnitude was 1.30 +/- 0.60 D (range, 0 to 4.00 D) at 6 months and vector change in astigmatism axis was 65 degrees +/- 68 degrees. Spherical equivalent refraction did not change when Arc-T was performed after PRK for eyes with low astigmatism (P = .4). Arc-T retreatment was performed in 6 of 37 (16%) eyes that had Arc-T before PRK and 18 of 86 (21%) eyes that had Arc-T after PRK (P = .12). CONCLUSION: Arcuate transverse keratotomy performed prior to PRK for high astigmatism or after PRK for lower levels of residual astigmatism effectively improved visual outcome. Coupling was less predictable for high levels of astigmatism correction with Arc-T.

Adult↗

Neurological assessment.

This article discusses the use of the Glasgow Coma Scale and its role as part of an holistic neurological assessment.

Glasgow Coma Scale↗

A sense of purpose.

Explore the source record for details and available documents.

Cerebral Palsy↗

Bleeding isolated gastric varices: a retrospective analysis.

OBJECTIVE: Isolated gastric varices (IGV) are rare and are believed to be associated with left-sided portal hypertension. We studied patients presenting with bleeding from IGV and compared them with those bleeding from both esophageal and gastric varices. METHODS: A retrospective analysis of 14 patients with bleeding from IGV was carried out. Portovenography findings (pattern of collateralization and natural shunts) in these patients were compared with a matched group of 69 patients with both esophageal and gastric varices. RESULTS: Of 14 patients with IGV, 2 had isolated splenic vein thrombosis and 12 had generalized portal hypertension. Portovenograms in 11 of the latter 12 revealed predominantly 'left-sided' collateralization in 8 patients as compared to 17 of 69 (25%) patients with esophageal and gastric varices (p = 0.004); natural shunts were seen in 6 of 11 cases and 15 of 69 (22%) patients in the two groups, respectively (p = 0.05). Abdominal devascularization operation gave good short- and long-term control of bleeding. CONCLUSIONS: Contrary to belief most patients with isolated gastric varices may have generalized portal hypertension rather than splenic vein obstruction as the cause and hence should be treated by a more extensive procedure than just splenectomy. The IGV could be a result of predominant collateralization to the retroperitoneal area (left-sided collateralization and natural shunts) rather than the usual pattern to the azygos system which results in esophageal varices.

Esophageal and Gastric Varices↗