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Biomedical subjects

S Parekh

Publications and source records attributed to S Parekh.

At least 19 recordsLinked to original sources
PubMed2003

Zidovudine-related anemia with reticulocytosis.

In patients infected with human immunodeficiency virus (HIV), zidovudine has been known to cause a severe hypoproliferative anemia that resolves promptly when the drug is stopped. Some patients, however, may come to medical attention after having stopped taking the drug for 1-2 weeks and may already be in the recovery phase and present with severe anemia, normoblastemia, and reticulocytosis. These features can be mistaken for hemolytic disease, as shown by our experience with three such patients.

Adult↗
PubMed2001

Development of a novel probe for measuring drug binding to the F1*S variant of human alpha 1-acid glycoprotein.

A novel probe was developed to measure drug association with the F1*S variant of the human serum protein alpha 1-acid glycoprotein (AGP). The molecule 2-hydroxy-3,5-diiodo-N-[2(diethylamino)ethyl]benzamide (DEDIC) binds to AGP, quenching its native fluorescence. This quenching was fitted to a two-site model giving apparent dissociation constants of 0.049 +/- 0.005 and 12 +/- 2 microM (mean +/- SEM). Quenching of each of the separate variants of AGP by DEDIC was itself described by a two-site model, giving for the F1*S variant K(D)(1)((F1*S)) = 0.041 +/- 0.010 microM and K(D)(2)((F1*S)) = 29 +/- 7 microM; and for the A variant K(D)(1)((A)) = 0.31 +/- 0.18 microM and K(D)(2)((A)) = 8.8 +/- 0.7 microM. The utility of DEDIC in probing drug interactions with isolated variants was demonstrated in competition experiments with the model drugs amitriptyline and bupivacaine. In addition, the selectivity of DEDIC for variant F1*S rendered it capable of probing the binding of drugs (including the variant A-selective drug amitriptyline) to F1*S in a mixture of variants, such as occurs naturally in whole AGP. DEDIC is unique as an F1*S variant-selective probe of drug binding to whole AGP that is also sufficiently soluble to serve as a probe of drug binding to the lower affinity sites on isolated A and F1*S variants.

Anesthetics, Local↗
PubMed2001

Combined factor VIII and IX deficiency in a family.

A family with combined deficiency of factor VIII and factor IX is reported. Family study showed that the father and his nephew had mild factor VIII deficiency with normal von Willebrand factor antigen and factor IX levels while his two sons had a reduced level of factor IX and normal factor VIII levels. His wife was found to have marginally reduced factor IX levels, whereas his daughter had reduced or normal levels of both factors VIII and IX. DNA analysis using the intra- and extragenic markers of factor VIII and IX genes showed that mother is a carrier of haemophilia B and the daughter is a carrier for both haemophilia A and B. Thus, the combined deficiency observed was due to a chance association of two distinct genetic defects.

Adult↗
PubMed2000

Improvement of microbial strains and fermentation processes.

Improvement of microbial strains for the overproduction of industrial products has been the hallmark of all commercial fermentation processes. Conventionally, strain improvement has been achieved through mutation, selection, or genetic recombination. Overproduction of primary or secondary metabolites is a complex process, and successful development of improved strains requires a knowledge of physiology, pathway regulation and control, and the design of creative screening procedures. In addition, it requires mastery of the fermentation process for each new strain, as well as sound engineering know-how for mediaoptimization and the fine-tuning of process conditions. This review focuses on the various options that may be employed to improve microbial strains and addresses the complex problems of screening, the tools and technology behind the selection of targeted organisms, and the importance of process optimization. Furthermore, this review discusses new and emerging technologies and designing optimized media for tracking mutants with enhanced productivity or other desired attributes.

Bacteria↗
PubMed1997

Peyronie's disease is associated with Paget's disease of bone.

Peyronie's disease is an idiopathic disorder in which an inflammatory fibrosis occurs in the tunica albuginea of the corpora cavernosa which causes the erect penis to become deformed. Peyronie's disease has a prevalence of 1% in men over age 50 years. Paget's disease of bone is a chronic skeletal disease with areas of increased bone turnover leading to pain, deformity, and in some cases arthritis. Because of a high rate of Peyronie's disease in subjects in a Paget's disease industry-sponsored drug trial, we asked whether there was an association between Peyronie's disease and Paget's disease of bone. We evaluated 61 men with Paget's disease attending our clinic for metabolic bone disease in a tertiary referral hospital, reviewed hospital records of all men discharged from our three hospitals with the diagnosis of Peyronie's disease, and mailed a validated questionnaire about shape of the erect penis to 1500 male members of the Paget Foundation. In the clinic population of men with Paget's disease of bone, 51 of 61 (83.6%) reported having normal erections; 10 patients (16.4%) were impotent. Sixteen of the 51 men (31.4%) had developed a bend or deformity in their erect penis which was confirmed by a urologist's examination to be Peyronie's disease. When the men with Paget's disease with and without Peyronie's disease were compared, there was no difference in their ages, years with Paget's disease, or serum alkaline phosphatase level. Upon medical record review, 1 patient of 262 (0.4%) with Peyronie's disease was found to have Paget's disease of bone. The men with Paget's disease returned their questionnaires for a response rate of 44.8% and reported Peyronie's disease with a prevalence of 14.5%. We suggest that Peyronie's disease is associated with Paget's disease of bone. Furthermore, we suggest that Peyronie's disease may be a previously unrecognized complication of Paget's disease of bone.

Aged↗
PubMed1993

Paraneoplastic pemphigus presenting as an unusual bullous eruption.

We describe a patient with a widespread annular bullous eruption on the trunk and extremities and involvement of the conjunctivae, oral mucous membranes, and esophagus. Findings of a biopsy specimen of an intraabdominal mass revealed nodular and diffuse well-differentiated lymphoma. Histologic examination of a skin lesion showed acantholysis with bulla formation and keratinocyte necrosis. Direct immunofluorescence testing of a skin lesion showed intercellular deposition of IgG. The patient's serum contained autoantibodies with broad specificity for skin and other epithelia and identified the characteristic bands of paraneoplastic pemphigus at 250, 230, 210, and 190 kd on immunoprecipitation. The patient died despite therapy.

Adult↗
PubMed1988

Pericardial cyst. A rare mass abutting the aorta.

Pericardial cysts are infrequently found. They are generally located in the cardiophrenic angle, dominantly on the right side. We present an example of a pericardial cyst in the anterior mediastinum abutting the ascending aorta.

Aged↗
PubMed1988

Magnetic resonance imaging of the orbits using a binocular surface coil.

Sixty subjects, including 12 normal volunteers, have been studied using the Aberdeen 0.08 T magnetic resonance imager. A wide range of pathological conditions, including both ocular and and orbital disease, have been examined using a specialized binocular surface coil. The images produced using this coil are superior to those made with a head coil and have the advantage of demonstrating both eyes simultaneously. Each patient has been studied using a pulse sequence combining alternate saturation-recovery and inversion-recovery pulses. The resultant short time-to-inversion inversion-recovery and saturation-recovery images have been shown to be accurate in demonstrating the normal anatomy of the globe and orbit and for the demonstration of a wide range of disease states.

Abscess↗
PubMed1984

Computer programs in nucleic acid synthesis: synthetic strategy development using solid-phase chemical techniques with data storage, retrieval and analysis capabilities.

A computer program has been designed to aid development of synthetic strategies for oligonucleotides produced by solid-phase chemical techniques. The program reduces the time required to develop a strategy and a data file from hours to minutes. The program contains inventories, provides cost analyses, and generates and stores other associated data. The program searches an inventory of sequences for that sequence to avoid duplicate synthesis. If the sequence is not in the inventory the program devises a synthetic strategy, calculates the amounts of reagents and labor costs necessary to complete the synthetic oligonucleotide. The program also deducts the reagents from inventory files. Physical data is also calculated. A file is generated in a sequence inventory for storage of the data as well as other data that will be generated during the purification processes. All variable parameters can be easily edited. The programs were designed to provide a cross-referencing feature for data analysis and can use several parameters as a constant.

Base Sequence↗
PubMed1984

Computer programs in nucleic acid synthesis: synthetic strategy development using solid-phase chemical techniques with data storage, retrieval and analysis capabilities.

A computer program has been designed to aid development of synthetic strategies for oligonucleotides produced by solid-phase chemical techniques. The program reduces the time required to develop a strategy and a data file from hours to minutes. The program contains inventories, provides cost analyses, and generates and stores other associated data. The program searches an inventory of sequences for that sequence to avoid duplicate synthesis. If the sequence is not in the inventory the program devises a synthetic strategy, calculates the amounts of reagents and labor costs necessary to complete the synthetic oligonucleotide. The program also deducts the reagents from inventory files. Physical data is also calculated. A file is generated in a sequence inventory for storage of the data as well as other data that will be generated during the purification processes. All variable parameters can be easily edited. The programs were designed to provide a cross-referencing feature for data analysis and can use several parameters as a constant.

Computers↗
PubMed1979

Synthesis and pharmacology of potential beta-blockers.

Several 1-(4-substituted phenoxyl)-2-hydroxy-3-isopropylaminopropanes and 1-(4-substituted phenoxy)-2-hydroxy-3-[3,4-dimethoxyphenethyl]aminopropanes were synthesized for possible beta-adrenergic receptor blockage. The compounds were synthesized by reaction of the 4-substituted phenol with epichlorohydrin and subsequent opening of the resulting epoxide with either N-isopropylamine or N-3,4-dimethoxyphenethylamine. Preliminary biological testing indicated a decrease in the beta-blocking potency and the duration of action.

Adrenergic beta-Antagonists↗