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Biomedical subjects

M Johnson

Publications and source records attributed to M Johnson.

At least 775 records · Page 43Linked to original sources
PubMed1980

Predicting the outcome of psychotherapy. findings of the Penn Psychotherapy Project.

Our study of predictability of outcomes of psychotherapy used predictions of two kinds: (1) direct predictions by patients, therapists, and clinical observers; and (2) predictive measures derived from the same sources. Seventy-three nonpsychotic patients were treated in psychoanalytically oriented psychotherapy (mean, 44 sessions). Two thirds of the therapists were residents in psychiatry; one third were more experienced. The two main composite outcome measures, measured at termination, were Raw Gain (residualized) and Rated Benefits, which intercorrelated at .76. Most patients improved and showed a considerable range of benefits. The clinical observers' direct predictions of Rated Benefits were highest (.27, P less than 905). The success of the predictive measures were generally insignificant, and the best of them were in the .2 to .3 range meaning that only 5% to 10% of the outcome variance was predicted. The Prognostic Index Interview variables did the best (eg, emotional freedom composite, .30; a crossvalidation for 30 patients was .39 (P less than .05). Neither the therapist measures nor the early psychotherapy session measures predicted significantly. Reanalysis of the similar Chicago Counseling Center study, in our terms, showed a similar low level of prediction success, eg, adequacy of functioning, marital status match, and length of treatment predicted significantly in both studies.

Adolescent↗
PubMed1980

Impulsivity: a multidimensional concept with developmental aspects.

Fifty-five preschool children were administered a number of tests purported to measure impulsivity: Delay of Gratification, Walk-the-Line-Slowly, Matching Familiar Figures Test, Schenectady Kindergarten Rating Scales, a teacher rating scale, and the Porteus Maze Test. Analyses indicated that impulsivity is multidimensional, with age-, sex-, IQ-, and teacher-related types. The results suggested that multiple indices are essential to the measurement and study of impulsivity. An interaction between sex and age of child was also revealed with respect to type and rate of activity. While 3- and 4-year-old girls differ radically from boys in type and rate of motor activity (fine muscle vs. gross muscle), 5-year-olds were virtually identical.

Age Factors↗
PubMed1980

Effect of insulin treatment on prostacyclin in experimental diabetes.

Diabetic patients have a high susceptibility to microvascular complications, atherosclerosis and thrombosis. Platelet hyperreactivity possibly related to an imbalance in arachidonic acid metabolism may be involved. Aortic rings or renal cortex produced a potent inhibitor of platelet aggregation, identified as prostacyclin (PGI2). Release of PGI2 by tissues from streptozotocin -- diabetic rats (aorta: 0.07 +/ 0.1 ng/mg wet weight; renal cortex 0.004 +/- 0.001 ng/mg wet weight) was significantly depressed when compared with controls (aorta: 0.26 +/- 0.07 ng/mg wet weight; renal cortex: 0.009 +/- 0.001 ng/mg wet weight). Treatment of diabetic animals with insulin for 8 days restored PGI2 production to normal. The finding that PGI2 is depressed in the aorta and in the kidney, tissues which develop angiopathy, and that this is normalised by insulin, suggests that impaired PGI2 production, perhaps associated with platelet hyperreactivity may play a role in the vascular complications of diabetes.

Animals↗
PubMed1980

Studies on the importance of the asparagine residue in oxytocin. Synthesis and some pharmacological properties of [1-alpha-mercaptoacetic acid, 5-isoasparagine] oxytocin.

[1-Alpha-Mercaptoacetic acid, 5-isoasparagine] oxytocin was synthesized to study the effects of moving the side chain carboxamide group of the amino acid residue in position 5 of oxytocin from the beta to the alpha position. The analog has an isoasparagine residue in position 5 and the 20-membered ring size of oxytocin is maintained by substituting cysteine in position 1 of oxytocin by alpha-mercaptoacetic acid. The analog was found to possess 0.098 +/- 0.002 U/mg of uterotonic activity but no milk-ejecting, antidiuretic or rat pressor activity could be detected. The substance did not inhibit the uterotonic or milk-ejecting activity induced by oxytocin nor the antidiuretic or rat pressor responses to the USP posterior pituitary standard. These results, together with the data available in the literature, indicate that an analog of oxytocin lacking the asparagine residue in position 5 is neither an agonist nor an antagonist. The observations may mean that the asparagine residue is critically important for the interaction of oxytocin with its receptor.

Amino Acid Sequence↗
PubMed1980

Biofunctional evaluation of a hydrogen bond stabilizing the beta-turn in the acyclic part of oxytocin.

In a continued effort to determine the importance of the hydrogen bonds for stabilization of the biologically active conformation of oxytocin, deamino-[9-glycolicamide] oxytocin was synthesized in order to study, in this respect, the hydrogen bond between the peptide N--H of Gly9 and the C=0 of Cys6. In this analog the amide linkage between residues at positions 8 and 9 is replaced by an ester. Thus the residue at position 9 cannot be involved in hydrogen bond formation with the C=O of Cys6. Deamino-[9-glycolicamide] oxytocin exhibited 134 +/- 13 U/mg and 355 +/- 48 U/mg of uterotonic activity in absence and in presence, respectively, of Mg2+, 108 +/- 8 U/mg of milk-ejecting activity, 0.35 +/- 0.03 U/mg of pressor activity and 2.5 +/- 0.1 U/mg of antidiuretic activity. It is concluded that the hydrogen bond under question is not critical for the conformation required for biofunctional interaction of oxytocin with its receptors in the uterus, mammary gland and other target organs.

Amino Acid Sequence↗
PubMed1980

A familial polymorphic variant of chromosome 5.

Two male fetuses and their mothers, referred for amniocentesis because of high levels of AFP in their blood, were found to carry an anomalous chromosome 5 with a large heterochromatic segment in the long arm. One of the fetuses had an additional ring chromosome.

Adult↗
PubMed1980

Renal biopsy in acute allograft rejection. Significance of moderate vascular lesions in long-term graft survival.

55 renal allograft biopsies obtained during acute rejection episodes resistant to standard antirejection therapy in 36 renal transplant recipients were reviewed and the findings correlated with long-term graft prognosis. 20 patients demonstrated moderate vascular pathology (group A), while 16 patients demonstrated changes consistent with pure cell-mediated rejection wit no vascular lesions (group B). Groups were similar with respect to age range, duration of haemodialysis, sex and antigen match. Of patients with vascular changes, 11 had arterial changes, 9 had arteriolar changes and 6 had arterial and arteriolar changes. The cumulative graft survival for group A was significantly less than that for group B at all post-transplantation intervals up to 24 months (p < 0.001).

Adult↗
PubMed1980

Therapeutic trials of antibiotic associated colitis.

Since September 1977 we have seen 63 patients with Clostridium difficile and a faecal toxin, but only 33 had histological evidence of pseudomembranous colitis. We have conducted separate double blind trials of an antibiotic, vancomycin and an anion-exchange resin, colestipol, in patients with post-operative diarrhoea. Vancomycin was extremely effective at eradicating the organism and its faecal toxin. These changes were associated with a marked symptomatic improvement. Colestipol proved ineffective in absorbing the faecal toxin and caused no change in numbers of Clostridial difficile. There was no associated symptomatic response. Neither drug had any effect on diarrhoea not related to Clostridium difficile. A carrier state was created by those patients who continued to excrete the organism after Colestipol or placebo treatment. This was eradicated by subsequent treatment with vancomycin. Our brief experience with metronidazole is discussed and a rational basis for treatment advocated.

Anti-Bacterial Agents↗
PubMed1980

Calcium distribution within human erythrocytes.

In order to study 45Ca distribution within erythrocytes, a method was devised that had minimal deleterious effects on the treated erythrocytes. It was observed that newly introduced 45Ca was predominantly recoverable from the cytosol and exchanged relatively slowly with membrane-associated Ca. Younger erythrocytes appeared to have relatively more 45Ca in membrane-associated sites. Erythrocytes from patients with sickle cell anemia had significantly more 45Ca in membrane-associated sites than did normal controls or patients with reticuloctosis due to a variety of disorders. There are theoretical reasons for considering the possibility that the distribution of 45Ca between cytosol and membrane-associated sites could modulate some of the properties of the erythrocyte membrane.

Anemia, Sickle Cell↗
PubMed1980

Calcium distribution within human erythrocytes during endocytosis.

In order to study 45Ca movements within erythrocytes, a method was devised that had minimal deleterious effect on the treated erythrocytes. Agents that induce endocytosis in intact erythrocytes (primaquine, vinblastine, and chlorpromazine) caused a prompt movement of 45Ca from cytosol to membrane-associated sites. This drug-induced movement of 45Ca to membrane sites was blocked by depleting erythrocytes of adenosine triphosphate (ATP) or by incubating them with known inhibitors of endocytosis, NaF of N-ethylmaleimide (NEM). It appears that endocytosis in intact human erythrocytes involves the movement and redistribution of 45Ca from cytosol to membrane-associated sites. Therefore, in the erythrocyte, as in perhaps other cells, movement of Ca from one site to another may modulate important cellular biologic functions.

Adenosine Triphosphate↗
PubMed1979

Clinical and pathological features of six cases of sarcoidosis presenting with renal failure.

Six patients with biopsy-proven renal sarcoidosis presented with renal failure of unknown origin; in none was the diagnosis of sarcoidosis initially considered. The serum creatinine concentration at the time of presentation ranged from 265 to 1380 mumol/l (3.0 to 15.6 mg/dl), with a mean of 787 mumol/l (8.9 mg/dl). Although only two patients were hypercalcemic at the time of presentation, the 24-hour urinary excretion of calcium was increased in three of the four patients in whom it was measured, and renal calculi were present in one case. Renal biopsy revealed interstitial nephritis and tubular atrophy in all cases, as well as nephrocalcinosis in three cases and noncaseating granulomas negative for acid-fast bacilli in four cases. In each patient steroid therapy led to a rapid improvement in renal function (mean post-treatment serum creatinine level 274 mumol/l [3.1 mg/dl]). The follow-up period ranged from 8 months to 8 years (mean 3.0 years). In three patients renal function remained stable with low-dose steroid therapy. In two cases recurrent hypercalcemia and deteriorating renal function accompanied steroid withdrawal but resolved with its reinstitution. In one additional case reversible deterioration in renal function accompanied tapering of the steroid dose; however, there was no hypercalcemia.This report emphasizes the importance of considering sarcoidosis in the differential diagnosis of acute renal failure of unknown origin. Long-term follow-up of such patients is essential, as relapse is common.

Acute Kidney Injury↗
PubMed1979

A deletion mutation in glucosephosphate isomerase (GPI Denton).

A new genetic variant form of glucosephosphate isomerase has been found in a family heterozygous for the mutant allele. The mutant enzyme, unlike other phenotypic variants, does not appear to be the result of a single amino acid replacement. The allozyme exhibits an isoelectric point of 5.7 and is thus much more acidic than the normal enzyme (pI = 9.3). The allozyme has been isolated from placenta and separated from the normal homodimer and heterodimer by isoelectric focusing. The enzyme exhibits normal Km and Ki values for the substrates and competitive inhibitors. The allozyme exhibits a normal pH optimum and thermal stability. However, the molecular specific activity of the variant enzyme as quantitated by radioimmunoassay is significantly lower than normal. Analytical gel filtration revealed that the molecular weight of the weight of the enzyme is significantly lower than the normal enzyme. These data thus suggest that the phenotype is unlike any previously reported and is due to a deletion mutation.

Alleles↗