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Biomedical subjects

K King

Publications and source records attributed to K King.

At least 127 records · Page 7Linked to original sources

MRSA revisited.

Explore the source record for details and available documents.

Humans↗

Isolation of gram quantities of EcoRI restriction and modification enzymes from an overproducing strain.

Structural genes for EcoRI restriction endonuclease and modification methylase have been inserted into the plasmid vector pKC30 (Shimatake, H., and Rosenberg, M. (1981) Nature (Lond.) 292, 128-132) downstream from the bacteriophage lambda pL promoter. Upon induction of pL expression in strains producing a thermolabile lambda cI857 repressor, synthesis of EcoRI polypeptides is enhanced to the extent that after 4 h they represent several per cent of the total cell protein. Purification of activities overproduced in this manner yields preparations of endonuclease and methylase which appear identical to those obtained from conventional sources, with overall yields corresponding to 0.5 to 0.9 g of each enzyme/kg of cell paste.

DNA Restriction Enzymes↗

A dose-response study of I3-cis-retinoic acid in acne vulgaris.

13-cis-retinoic acid has been used as a single agent in the treatment of seventy-six patients with previously unresponsive cystonodular acne. The study was carried out in a double-blind fashion using three doses of the drug. Ninety per cent of the patients responded with a 70% improvement in the acne severity. Sixty-six per cent of the patients experienced no further problems with their acne during follow-up. Side-effects were frequent. The 0.5 mg/kg b.w. dose is recommended for the initial course of treatment.

Acne Vulgaris↗

Antibiotic-resistant staphylococci in a teaching hospital.

A large, continuing outbreak of infection and colonisation with a Staphylococcus aureus which is resistant to methicillin and gentamicin is reported. Affected patients and staff members seen between September, 1980, and August, 1981, are reviewed in detail. Methods of management of such persons and their treatment, if required, are discussed. The antibiotic-resistant Staph. aureus is readily disseminated in hospitals and may cause outbreaks of infection in wards, which require isolation of affected patients in the attempt to control the problem. It is suggested that a special isolation unit is needed. Use of the few effective antibiotic agents should be restricted. Despite these measures, the spread of this organism may not be contained.

Adult↗

A double-blind study of the effects of 13-cis-retinoic acid on acne, sebum excretion rate and microbial population.

Forty-eight acne patients were treated orally with 13-cis-retinoic acid in a double-blind dose response study. There was a marked clinical improvement with a concomitant reduction in sebum excretion rate (SER) and production rate of free fatty acids (FFA). Microbial numbers decreased significantly; the decrease in propionibacteria was greater than that of aerobic bacteria. The decline in micro-organisms occurred after the reduction in sebum and FFA production. This suggests that the effect of the drug upon micro-organisms is secondary to the change in sebum excretion but it is nevertheless an important factor in the resolution of the acne.

Acne Vulgaris↗

Heat stress in motor vehicles: a problem in infancy.

Children have died from heat stress because they have been left in closed automobiles. Changes in the internal temperature of various sized automobiles left in the Brisbane summer sun were examined. With all windows and doors closed, this temperature rose from an ambient level of 36 C to a maximum of 67 C within 15 minutes and remained there until the doors were opened. Slightly lower temperatures were found for light colored sedans and station wagons. However, all readings were significantly above ambient and all produced an environment unacceptable for a child. Temperatures approaching ambient were only achieved with ventilation provided by windows at least 200 mm (half) open. A lesser gap (50 mm) resulted in interior temperatures exceeding 50 C, which is still too hot for children. Infants left in such an environment will lose fluid quickly from sweat and could become as much as 8% dehydrated in four hours. Subsequently the cerebral manifestations of heat stroke would ensue. Parents and pediatricians should be warned of the danger of heat stress if children are left in a closed automobile.

Australia↗

Chemical modification of the histidine residue in basic phospholipase A2 from the venom of Naja nigricollis.

Phospholipase A2 from Naja nigricollis venom was separated into three fractions by chromatography on a column of CM-Sephadex C-25. The pI values of fractions CMS-5, CMS-6 and CMS-9 were determined to be 7.6, 8.3 and 10.6, respectively. Fraction CMS-9 was further purified on a DEAE-Sephacel column and the homogeneity was verified. The specific activity of CMS-9 was found to be 1300 units per mg and lethal toxicity 0.3 mg per kg mouse. The most basic and toxic fraction, CMS-9, was subjected to chemical modification with p-bromophenzcyl bromide. The enzyme lost both the enzyme activity and lethal toxicity, however, the antigenicity remained unchanged. Although both 8-anilinonaphthalenesulfonate and Ca2+ showed pronounced protection on the inactivation process, the mechanism of 8-anilinonaphthalene-sulfonate protection is different from that of Ca2+. Amino acid analysis showed that only one (His-47) out of three histidine residues was modified. Although both native and His-modified CMS-9 were perturbed by the presence of Ca2+, the modified enzyme lost the characteristic tryptophan blue shift suggesting that the modified enzyme is unable to exert a charge effect upon Ca2+ binding in the vicinity of the tryptophan group. Scatchard plots revealed only one type of binding sites for 8-anilinonaphthalenesulfonate in the presence of Ca2+. On the other hand, the modified enzyme lost the ability to bind 8-anilinonaphthalene. It is suggested tentatively that the hydrophobic pocket in which 8-anilinonaphthalenesulfonate is bound may be the site of the enzyme that interacts with phospholipid.

Acetophenones↗