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Biomedical subjects

C Shah

Publications and source records attributed to C Shah.

31 records · Page 2Linked to original sources
PubMed1990

Cytoplasmic and periplasmic expression of a highly basic protein, human interleukin 4, in Escherichia coli.

Human IL-4 (hIL-4) has been cloned from a human T cell line based on its homology to the murine IL-4 cDNA sequence. We have compared cytoplasmic and extra-cytoplasmic expression of this basic protein in Escherichia coli using various combinations of promoters, replicons and host strains. Strains producing a cytoplasmic product were most successful at heterologous protein expression, producing up to 500 mg/l of an inactive aggregated form of the protein. The biological activity of the protein could be restored by refolding the protein with guanidine hydrochloride and glutathione giving a specific activity identical to that of IL-4 derived from CHO cell lines stably transformed with an hIL-4 expression plasmid. Strains designed to secrete human IL-4 into the periplasmic space produced far less protein (approximately 5 mg/l). However, a significant fraction of this protein was detected in the culture medium. This fraction appeared to be soluble after ultracentrifugation, and demonstrated high specific activity without refolding. Leakage of heterologous protein into the culture medium may be a viable way to recover biologically active products without relying on the denaturation and refolding in vitro that can, at times, yield incorrectly folded gene product.

Amino Acid Sequence↗
PubMed1983

The pectoralis major myocutaneous flap: an angiographic study.

A new era in head and neck reconstruction has been opened with the use of myocutaneous flaps. The pectoralis major myocutaneous flap is considered the most reliable of its kind but flap failures still occur secondary to tension and infection. Our standard procedure has been to follow the acromioxiphoid line as a guide to the location of the blood supply of the pectoralis major muscle. We have noticed in the operating room and during cadaver dissection that the vascular supply is sometimes more laterally located than usually described. A review of the vascular supply of this anatomic area using angiographic studies of the subclavian and its branches is presented, with important findings critical to the surgical technique used to protect the flap's blood supply.

Adult↗
PubMed1975

Standardization of Dermatophagoides pteronyssinus extracts and tyrosine adsorbates.

Human skin test, inhibition of RAST and the radioimmunosorbent technique of Ceska have been shown to be useful assays for the standardization of D. pteronyssinus aqueous extracts. The development of these assay systems for the standardization of D. pteronyssinus tyrosine adsorbed formulations is described. Tyrosine solubilisation procedures are detailed together with the influence of these procedures on the three assays. Good correlation has been shown between the human skin test and the radioimmunosorbent technique. The inhibition of RAST appears to be more sensitive than the other techniques to mild conformational changes in the allergen, induced in this work by acid pH. This may limit its value for the standardization of D. pteronyssinus tyrosine adsorbates but it may prove useful in monitoring manufacturing processes.

Adsorption↗
PubMedDate not supplied

Prehospital interventions in children.

OBJECTIVES: Frequently performing procedures assists in skill maintenance. This study was conducted to characterize frequency and types of basic and advanced prehospital interventions performed on children. METHODS: A retrospective study was conducted over a three-month period from emergency medical services (EMS) units working in central Michigan. Data were collected for age, sex, at-scene time, total run time, basic procedures (e.g., spinal immobilization), and advanced procedures (e.g., venous access). RESULTS: A total of 535 EMS runs were reviewed. Runs were excluded for transport refusal (105) and site-to-site transfer (6). Of the remaining 424 children, 287 received an intervention (group 1) and 137 did not (group 2). Group 1 (9.5 +/- 5.6 years) was older (p < 0.001) than group 2 (6.0 +/- 5.8 years). There was no gender predominance between group 1 and group 2 (p = 0.06). In group 1 there were 104 patients who received multiple procedures. Basic procedures (n = 382) included spinal immobilization (149), oxygen administration (123), splinting (27), wound care (24), use of military anti-shock trousers (4), and cardiopulmonary resuscitation (1). Advanced procedures (n = 112) included venous access (65), medications of all routes (26), and cardiacoximetry monitoring (21). No child had an intraosseous line started and no child was successfully intubated. Only 82 of the 424 children (19.3%) had an advanced procedure. Group 1 at-scene times (16.1 +/- 8.1 min) were longer (p < 0.001) than those of group 2 (11.1 +/- 6.6 min). Total run times for group 1 (35.7 +/- 15.5 min) were longer (p < 0.001) than those for group 2 (26.7 +/- 11.3 min). CONCLUSIONS: Advanced EMS procedures were performed on only 19.3% of children. Opportunities to perform critical interventions (e.g., intubation) were rarely present. Children receiving procedures were older and had longer scene and run times.

Child↗