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Biomedical subjects

M Shah

Publications and source records attributed to M Shah.

At least 91 records · Page 5Linked to original sources
PubMed1998

Adenovirus vectors as transcomplementing templates for the production of replication defective retroviral vectors.

We have generated an adenovirus containing a retroviral vector sequence encoding the neomycin phosphotransferase (neo) gene (AV-LXSN). AV-LXSN transduction of retroviral packaging cell lines led to production of LXSN retroviral vector with alternative viral envelopes; exposure of target cells to retroviral containing supernatants confirmed envelope specific tropism. Retroviral titers (G418 cfu/ml) were comparable to those produced by standard techniques. Retrovirus could be detected in supernatants within 24 hours of AV-LXSN transduction and persisted as long as 120 hours. Southern blot analysis of DNA purified from populations of G418 cells showed the presence of a single neo containing restriction fragment of the appropriate size that could only be generated by reverse transcription of LXSN to produce LXSN provirus. This adeno-retroviral chimeric vector system could simplify the generation and testing of different retroviral vectors, particularly where assessment of vectors with alternative envelopes carrying novel targeting ligands is required.

Adenoviridae↗
PubMed1998

Nickel as an occupational allergen. A survey of 368 nickel-sensitive subjects.

OBJECTIVE: To define the role of nickel as an occupational allergen. DESIGN: Survey using path-test results. SETTING: Contact dermatitis clinic in the university hospital of a large industrial British city. PATIENTS: Three hundred sixty-eight nickel-allergic patients seen during a 5-year period were assessed for the relevance of nickel contact in their workplace. Patients were divided into possible occupational nickel allergy and nonoccupational nickel allergy groups. RESULTS: Nickel was considered an occupational allergen or possible occupational allergen in 84 (22.8%) of 368 patients shown to be nickel sensitive on patch testing. The main workers in whom nickel was a common allergen were hairdressers, retail clerks, caterers, domestic cleaners, and metalworkers. Those for whom occupational exposure was possible had a significantly higher prevalence of hand dermatitis compared with the nonoccupational nickel allergy group. Nickel allergy seemed to function as a secondary occupational influence, often in conjunction with other factors, such as irritants. CONCLUSIONS: Although the overall importance of nickel as an occupational allergen cannot be easily assessed, there is evidence of its importance in some occupations, especially those involving wet work. The possibility that nickel is acting as an occupational allergen needs to be assessed on an individual basis, taking into account personal circumstances and environment, but particularly should be considered in patients with hand dermatitis.

Adolescent↗
PubMed1998

Adolescent depression: controlled desipramine treatment and atypical features.

The study was designed to test the efficacy of desipramine in adolescents with major depression (MDD). In addition, we assessed the presence of atypical features of MDD, consisting of mood reactivity and two of four associated features (rejection sensitivity, hyperphagia, hypersomnia, and leaden paralysis). Patients were randomized to desipramine (DMI) or placebo for 6 weeks, provided they failed to improve (e.g., meeting MDD criteria and a Hamilton Depression Scale score > or = 18) after 2 weeks on single blind placebo. Of 94 adolescents (ages 13-18) who were diagnosed as having MDD, 64 entered the study and 62 received placebo for 2 weeks. Of these, 45 were randomized to DMI or placebo. Completed analyses did not reveal significant improvement for the active treatment compared to the placebo. A large proportion of adolescents responded to placebo (50%), suggesting the need for very large samples to detect differential treatment efficacy, should it exist. A relatively high rate of atypical depression was observed (47% in the 64 patients entered). In view of the demonstrated specificity of monoamine oxidase inhibitor efficacy in adults with atypical features of MDD, this clinical subtype may have relevance to future investigation of therapeutic interventions in adolescent MDD.

Adolescent↗
PubMed1998

Three-dimensional reconstruction of the coronary arteries using a priori knowledge.

A method for 3D reconstruction of the coronary arteries from two radiographic images is presented. A novel technique for matching image structures is the main contribution of the work. After a comprehensive study of the knowledge required to approach this problem, an automatic method, which includes both numeric and symbolic procedures to solve geometric ambiguities, is developed. In the proposed method, all possible (virtual) reconstructions are first obtained. Their validity is evaluated by means of a priori knowledge about the 3D object and its projections. From the set of chosen possible solutions, the most likely solution is selected. The method is tested using real images and is implemented in a platform that allows further clinical validation.

Angiography, Digital Subtraction↗
PubMed1998

The role of adjunctive mitomycin C in secondary glaucoma triple procedure as compared to primary glaucoma triple procedure.

OBJECTIVE: This study aimed to investigate whether previously failed glaucoma filtration surgery is a risk factor for filtration failure of subsequent trabeculectomy combined with cataract surgery and to determine the role of adjunctive mitomycin C (MMC) in the secondary glaucoma triple procedure (SGTP) as compared to primary glaucoma triple procedure (PGTP). DESIGN: A prospective, controlled study that was randomized with respect to assignment to adjunctive MMC and a case-control design with respect to comparisons between SGTP and PGTP was studied. PARTICIPANTS: The SGTP group consisted of 49 eyes of 49 consecutive patients with primary open-angle glaucoma with a history of glaucoma filtration surgery requiring glaucoma medical therapy and in need of cataract surgery, randomized to adjunctive MMC (SGTP MMC subgroup of 21 eyes) and no adjunctive MMC (SGTP control subgroup of 28 eyes). The PGTP group consisted of 49 PGTP cases closely matched to the SGTP cases with respect to age, race, gender, MMC use, C:D ratio, and systemic diseases. INTERVENTION: Trabeculectomy combined with phacoemulsification and a small incision (5 x 6 mm), all polymethylmethacrylate posterior chamber intraocular lens implantation with or without adjunctive MMC (0.5 mg/ml for 1 minute), was performed. MAIN OUTCOME MEASURES: Surgery failure was defined as the need of an additional intraocular procedure or the need of more than one medication to achieve intraocular pressure control to the target level. Intragroup and intergroup comparisons were made with respect to filtration outcome among the SGTP and PGTP patients. RESULTS: Without adjunctive MMC, filtration success was significantly less in SGTP than in PGTP (P = 0.03). Adjunctive MMC significantly increased the success rate of SGTP (P = 0.02) but not that of PGTP (P = 0.89) over the average follow-up period of 2 years. CONCLUSIONS: Previously failed glaucoma filtration surgery is a significant risk factor for the filtration failure of combined surgery. Intraoperative use of adjunctive MMC significantly improves the filtration success rate of SGTP.

Adult↗
PubMed1998

Combined topical-peribulbar anesthesia for cataract surgery.

PURPOSE: To evaluate the anesthetic effect of single-point low-volume peribulbar anesthesia supplemented by topical anesthesia. SETTING: Private ambulatory ophthalmic practice. METHODS: Five hundred consecutive patients received 4 cc of lidocaine 2% with 200 units hyaluronidase as 1-point peribulbar anesthesia. This was supplemented by lidocaine 4%, 1 drop every 3 to 5 minutes for 3 instillations. Phacoemulsification and intraocular lens implantation were performed through a scleral tunnel or clear corneal approach. All patients were evaluated for intraoperative akinesia, lid closure, and anesthesia. One hour after surgery, the eye patch was removed and patients were evaluated for pain, discomfort, foreign-body sensation, diplopia, and lid closure. RESULTS: All patients had no pain to mild discomfort during surgery; 34% had total and 58% partial akinesia; 78% had poor orbicularis action (lid closure); 12% had subconjunctival hemorrhage. Postoperatively, 42% of patients had foreign-body sensation caused by conjunctival coaptation by diathermy or corneal edema. Diplopia occurred in 32% of patients but resolved within 1 hour after eye-patch removal, and partial ptosis occurred in 58%, resolving within 2 hours of patch removal. All patients had normal lid closure when the eye patch was removed. CONCLUSIONS: Low-volume 1-point peribulbar anesthesia supplemented by topical anesthesia was safe and effective and provided early visual recovery. Topical therapy can be started 1 hour postoperatively.

Administration, Topical↗
PubMed1998

Differential localization of heat shock proteins 90, 70, 60 and 27 in human decidua and placenta during pregnancy.

Little is known about the localization of heat shock proteins (HSPs) in the decidua and placenta during the course of normal pregnancy. In this study, we have examined the localization of the HSPs in decidual and placental tissues obtained from women during the first, second and third trimesters of pregnancy (five in each trimester) by immunohistochemistry using highly specific antisera. HSPs 90, 70, 60 and 27 were detected in decidual stromal cells during each trimester. The intensity of staining did not change during gestation for HSPs 60 and 27, whereas it decreased with advancing gestation for HSPs 90 and 70. HSPs 90 and 60 were localized primarily in the nucleus, whereas HSP 70 was present equally in the nucleus and the cytoplasm; HSP 27 was primarily in the cytoplasm. In the placenta, HSPs 90, 70 and 60 were localized in cytotrophoblast, syncytiotrophoblast, intermediate trophoblast, Hofbauer and endothelial cells. HSPs 90 and 60 were localized primarily in the nucleus, while HSP 70 was in the nucleus and the cytoplasm. In the placenta, HSP 27 was detected only in the intermediate trophoblast and syncytiotrophoblast cells and only in the first two trimesters. These results indicate that there are striking differences in the subcellular localization of HSPs in the decidua and the placenta during normal pregnancy.

Chaperonin 60↗
PubMed1998

Foot dermatitis in children: causative allergens and follow-up.

Allergic contact dermatitis from shoes may have a typical pattern of presentation, but we have found that the distribution of dermatitis is often unhelpful in establishing the diagnosis. In this study, we aimed to define the features of foot dermatitis in children and to assess its outcome, in comparison to adults with foot eruptions. Relevant allergens were found in 15 out of 29 children and 26 out of 57 adults with foot eruptions. The most common allergens in children were rubber chemicals and topical medicaments. Adults showed a similar pattern, but also reacted to clothing dyes. The prognosis in both groups was good, with the dermatitis improving or resolving in 2/3.

Adolescent↗
PubMed1998

Recurrent bleb infections.

AIM: To report the patient characteristics, causative organisms, and clinical outcomes in patients with recurrent bleb related ocular infections. METHODS: The medical records of all patients diagnosed with bleb related ocular infection at the New York Eye and Ear Infirmary over a 10 year period were reviewed. Recurrent bleb infection was defined as at least two episodes of bleb purulence with or without associated intraocular inflammation separated by a quiescent period of at least 3 months. RESULTS: Recurrent bleb infections developed in 12 eyes of 12 patients (10 men, two women) a mean of 16.3 (SD 17.9) months (range 3-51 months) after the initial infection. Two patients developed a third episode 3 and 20 months, respectively, after the second infection, yielding a total of 14 recurrent infection episodes. Recurrent infection developed after trabeculectomy in 11 eyes (adjunctive 5-fluorouracil, nine eyes; mitomycin C, one eye; no antifibrosis agent, one eye) and following cataract extraction with inadvertent bleb formation in one eye. Four (36.4%) of the filtered eyes had undergone trabeculectomy at the inferior limbus. The mean follow up time from filtering surgery to the first bleb related infection was 28 months for the nine patients treated with 5-fluorouracil and 14 months for the single patient treated with mitomycin C. 11 (78.6%) cases had a documented bleb leak in the 4 week period before or at the time of recurrent infection. Topical, prophylactic antibiotics had been used in 7/14 (50%) cases. The same organism was cultured from the initial and recurrent infections in 2/14 (14.3%) cases. CONCLUSION: Eyes that have been successfully treated for bleb related infection remain at risk for recurrent infection. No apparent correlation exists between organisms responsible for the initial and recurrent infections. The increased rate of recurrent bleb related infection in patients receiving adjunctive 5-fluorouracil compared to mitomycin C may have been related to the longer follow up of the 5-fluorouracil eyes.

Adult↗
PubMed1998

Maturation of rabbit proximal straight tubule chloride/base exchange.

The present in vitro microperfusion study compared the mechanism and rates of NaCl transport in neonatal and adult rabbit proximal straight tubules. In proximal straight tubules perfused with a late proximal tubular fluid and bathed in a serumlike albumin solution, the rate of volume absorption (JV) was 0.54 +/- 0.10 and 0.12 +/- 0.05 nl.mm-1.min-1 in adults and neonates, respectively (P < 0.05). With the addition of 10(-5) M bath ouabain, JV decreased to 0.27 +/- 0.07 and -0.03 +/- 0.04 nl.mm-1.min-1 in adult and neonatal tubules, respectively (P < 0.05), consistent with lower rates of active and passive NaCl transport in the neonatal proximal straight tubule. The effect of luminal sodium and chloride removal on intracellular pH was used to assess the relative rates of Na+/H+ and Cl-/base exchange. The rates of Na+/H+ and Cl-/base exchange were approximately fivefold less in neonatal proximal straight tubules than adult tubules. In both neonatal and adult proximal straight tubules, the rate of Cl-/base exchange was not affected by formate, bicarbonate, or cyanide and acetazolamide, consistent with Cl-/OH- exchange. These data demonstrate an increase in proximal straight tubule NaCl transport during postnatal renal development.

Aging↗
PubMed1998

Rapid recovery of a child with Guillain-Barré syndrome using intravenous immunoglobulins.

The purpose of this article is to acknowledge the success of using intravenous immunoglobulins in children with Guillain-Barré syndrome and to review the literature. A 17-year-old African-American young lady with Guillain-Barré syndrome of 11-days duration underwent intravenous immunoglobulin treatment. Within 6 days, the patient was ambulating and was showing significant signs of improvement. The use of intravenous immunoglobulins in children with Guillain-Barré syndrome has been reported in only a few instances.

Adolescent↗
PubMed1997

Protective effect of exogenous transferrin against hyperoxia: a study on premature rabbits.

We hypothesized that an increase in plasma iron binding capacity would decrease the generation of oxygen radicals and of lipid peroxides. To test this hypothesis, we studied whether supplementation of transferrin (TF) in premature rabbits would modify the degree of hyperoxic lung injury. Animals, delivered prematurely at 29 days of gestation (term 31 days), were randomized and given either 0.5 g/kg of albumin (Alb) (n = 116) or 0.5 g/kg of iron-free TF (n = 132) intravenously within 2 hours after birth. Another group was randomized to receive saline (n = 15), or either 0.35 g/kg (n = 12) or 0.70 g/kg of iron-free TF (n = 8). After exposure to a 100% oxygen environment for 2 or 4 days, the animals were killed, and plasma and bronchoalveolar lavage (BAL) fluid was recovered. Infusion of TF caused a dose-dependent increase in the concentration of TF and an increase in the unsaturated iron-binding capacity. Administration of TF at birth increased the gradient of TF between serum and alveolar epithelial lining fluid on day 4, suggesting decreased alveolar-capillary permeability. BAL fluid and plasma from TF-supplemented animals contained less lipid peroxidation products and more inhibitor of lipid peroxidation than BAL fluid or plasma from Alb-treated animals. In TF-treated animals, the recovery of protein in BAL fluid (TF group, 1.26 +/- 0.07 mg; Alb group, 1.78 +/- 0.10 mg; P = 0.02) and the water content of the extravascular lung tissue (TF group, 78.5 +/- 1.4%; Alb group, 83.2 +/- 1.3%; P = 0.05) were lower than in Alb-treated animals. We propose that supplementation of iron-free TF decreases iron-catalyzed redox reactions and may decrease hyperoxic lung injury in the premature.

Analysis of Variance↗