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K R Johnson

Publications and source records attributed to K R Johnson.

At least 181 records · Page 10Linked to original sources
PubMed1982

Joint segregation of biochemical loci in salmonidae. III. Linkage associations in Salmonidae including data from rainbow trout (Salmo gairdneri).

The results of 107 pairwise examinations of joint segregation of biochemical and skin color loci in rainbow trout, Salmo gairdneri, are presented. Three examinations revealed significant nonrandom assortment: Idh-3 with Me-2, Ada-1 with G3p-3, and Mdh-3, with Mdh-4. We believe the first two instances to be cases of classical linkage and the latter instance to reflect pseudolinkage based on similar findings in Salvelinus. All known salmonid linkage associations are reviewed. The results of this summary indicate a high degree of genome conservatism among genera within the Salmonidae, which would seem to be in contrast to the highly plastic genome of this family based on karyotypic data. Data are presented which negate the view that Robertsonian fusion of homologous acrocentric chromosome arms was the preferred mode of metacentric formation in salmonid evolution.

Albinism↗
PubMed1982

Laboratory differentiation of hypercalcemic patients.

We studied the biochemical discrimination of primary hyperparathyroidism from other causes of hypercalcemia. This potentially serious disorder is readily remedied, and because recent work has suggested that even very mild cases in elderly people derive substantial benefit from surgery, the correct diagnosis is crucial. A discriminant function is derived that maximizes the use of data that are readily available from general hospital laboratory; application of the Hamilton "T score" system simplifies its interpretation. We conclude that the best use of this formula is as a negative discriminant, to identify some non-hyperparathyroid cause of hypercalcemia, and also as a partial positive discriminant, to identify some cases of primary hyperparathyroidism. We review previous such discriminants and consider the reasons why they have been less successful.

Albumins↗
PubMed1980

Prophylactic vitamin D in the elderly.

A cross-section of an elderly population was assessed in a double-blind trial for the effects of prophylactic vitamin D. The subjects who completed the trial were assessed clinically, by physiotherapy tests of muscle function and by biochemical analysis, before and after a course of vitamin D or placebo. A significant fall in serum phosphate was found in the placebo group but not in the vitamin D group. The fall was maximal between the months of October and March which correspond to maximum and minimum amounts of circulating 25-hydroxy-vitamin D during the year. No difference in muscle function between treated and untreated groups was shown. Two out of 63 individuals on vitamin D developed hypercalcaemia. It is concluded that, although there appears to be improvement in the phosphate status of treated patients over the short term of this trial, hypercalcaemia after vitamin D administration precludes the continuous prophylactic use of vitamin D at the levels employed in this trial.

Aged↗
PubMed1980

Comparison of amoxicillin and ampicillin activities in a continuous culture model of the human urinary bladder.

Sixteen isolates of Escherichia coli were obtained from women with significant acute urinary tract infections who were subsequently treated with amoxicillin. The activities of amoxicillin and ampicillin against these organisms were compared in urine in a continuous culture apparatus which partly simulated the milieu of the human urinary bladder. After introduction of amoxicillin into the bladder model, mean viable counts for 14 susceptible strains (minimum inhibitory concentration less than or equal to 32 microgram/ml) at 10, 20, 30, and 45 min fell to 34, 8, 0.4, and 0.2% of the original. Corresponding figures for ampicillin were 56, 24, 11, and 2.4%. Viable counts obtained at seven timed intervals up to 2 h were significantly (P = 0.025) lower with amoxicillin than ampicillin. Both antibiotics had a similar activity in conventional disk susceptibility and surface plate minimum inhibitory concentration tests. The realism of the model was confirmed by comparing response to amoxicillin in vivo and in vitro. A serious discrepancy was seen in only one of the 16 cases.

Acute Disease↗
PubMed1977

The sulfophosphovanillin reaction for serum lipids: a reappraisal.

New evidence is presented for the mechanism of this reaction, which is used in estimating lipids. The reaction occurs in two stages: (a) Stage 1 evidently involves an oxidation step, forming a specific type of carbonium ion called an alkenyl cation of the general formula R--C+--C==C--R' (previous evidence had indicated that a carbonium ion of general formula R--C+--R' was formed by protonation only.) (b) Stage 2 of the reaction was examined by nuclear magnetic resonance studies and by partition experiments, which have indicated that a vanillin phosphate ester is not formed as previously suggested. Comparative data from other acid-aldehyde reactions indicate that in this reaction 1,1-di(4-hydroxy-3-methoxy phenyl)ethylene ion is formed, a product compatible with the formation of an alkenyl cation at stage 1.

Benzaldehydes↗
PubMed1976

Esophageal obturator airway: use and complications.

The esophageal obturator airway, in lieu of placement of an endotracheal tube, has been found to be an effective and reliably safe means of providing an artificial airway. By occluding the esophagus, it prevents gastric dilatation and aspiration. However, it is not totally without hazard. Two cases of pharyngoesophageal trauma are reported: a high esophageal tear found at post mortem examination and a pyriform sinus laceration noted on admission to the hospital. The authors recommend conservative treatment for cervical esophageal perforations and surgery for thoracic esophageal perforations. Despite these complications, the authors feel the esophageal obturator airway is safe and effective for use by those unskilled in direct endotracheal intubation when participating in cardiopulmonary resuscitation.

Adult↗