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Biomedical subjects

M Johnson

Publications and source records attributed to M Johnson.

At least 613 records · Page 34Linked to original sources
PubMed1989

Granulomatous angiitis masquerading as a mass lesion. Magnetic resonance imaging and stereotactic biopsy findings in a patient with occult Hodgkin's disease.

Granulomatous angiitis is a frequently fatal central nervous system vasculitis of unknown pathogenesis sporadically associated with Hodgkin's disease, mixed cellularity type. We describe a 58-year-old woman presenting with headaches, progressive spastic paraparesis, equivocal computed tomography findings, and magnetic resonance imaging findings of increased signal intensity biparietally on T2-weighted imaging in a relatively discrete pattern. Magnetic resonance imaging-directed serial stereotactic biopsies revealed granulomatous angiitis throughout the right parieto-occipital region and splenium. Simultaneous biopsy of an enlarged submandibular mass revealed Hodgkin's disease, lymphocyte-predominant type. This case shows that granulomatous angiitis may be associated with magnetic resonance imaging findings suggesting a mass lesion in lymphocyte-predominant as well as mixed cellularity Hodgkin's disease.

Brain↗
PubMed1989

Similarity of an estrogen-induced protein and a luteinizing hormone releasing hormone-induced protein.

Estradiol induces a 70 kDa protein ('EI70') which is synthesized in vivo in the female rat ventromedial hypothalamus (VMH) and transported to the midbrain central gray, suggesting a role for EI70 in the female mating behavior, lordosis. Luteinizing hormone releasing hormone (LHRH), in addition to stimulating gonadotropin release, potentiates pituitary responsiveness to subsequent exposure to LHRH (the 'priming' effect), facilitates lordosis and induces the synthesis of a 70 kDa protein ('LHRH70') in pituitary in vitro. We now report that EI70 precisely co-migrates on two-dimensional (2-D) gels with the pituitary protein induced by LHRH both in vitro and in vivo. Furthermore, both proteins migrate on 2-D gels in the vicinity of a protein recognized after immunoblotting by antibodies to the heat-shock-70 kDa protein family. The induction of a common protein by estrogen or LHRH could represent a common mechanism by which these hormones facilitate secretion, and by which these hormones interact.

Animals↗
PubMed1989

Issues in planning and interpreting active control equivalence studies.

Active control equivalence studies, with the goal of demonstrating therapeutic equivalence between a new and an active control treatment, are becoming more widespread due to current therapies that reflect previous successes in the development of new treatments. Because ethical requirements preclude the use of a placebo or no-treatment control for internal study validation, certain methodologic issues arise in active control equivalence trials that require special attention. We emphasize a special feature of this alternative study design, namely, its reliance on an implicit "historical control assumption". To conclude that a new drug is efficacious on the basis of an active control equivalence study (ACES) requires a fundamental assumption that the active control drug would have performed better than a placebo, had a placebo been used in the trial. In designing an ACES, one needs some assurance that historical estimates of the active control drug's efficacy relative to placebo are applicable to the new experimental setting. Steps that can be taken to compile such evidence and to justify the use of an active control equivalence design are described. These issues are illustrated in the context of a planned study to evaluate the efficacy of a new drug for the prevention of stroke, using aspirin as an active control.

Adult↗
PubMed1989

Advanced cryptogenic fibrosing alveolitis: preliminary report on treatment with cyclosporin A.

Seven patients with fibrosing alveolitis who failed to respond to prednisolone and cyclophosphamide and were deteriorating, were treated with cyclosporin A. An initial favourable response was seen but was not maintained. When compared to a control population, matched for the extremely severe disease present in the treated group, survival was doubled from 2.5 to 5 months. With growing awareness of the possibility of heart-lung transplantation in this disease, even this trivial increase in survival may be of crucial importance in individual patients.

Cyclosporins↗
PubMed1989

Hematological, anthropometric, and metabolic comparisons between vegetarian and nonvegetarian elderly women.

The purpose of this study was to investigate hematological, anthropometric, and metabolic differences in elderly women who were similar in most respects except for choice of diet. Nineteen vegetarian (V) and 12 non-vegetarian (NV) elderly women (mean ages 72.3 +/- 1.4 and 69.5 +/- 1.0 years, respectively) were recruited based on several selection criteria including race, religion, education, Quetelet Index, absence of major chronic disease and use of medications, physical activity, and geographic area. Average years of adherence by V and NV groups to dietary regimens were 46.3 +/- 3.3 and 69.6 +/- 1.0, respectively; Hematological comparisons revealed that the V elderly women had significantly lower glucose (4.60 +/- 0.09 vs 5.13 +/- 0.11 mmol/L), low-density lipoprotein cholesterol (3.14 +/- 0.19 vs 4.09 +/- 0.27 mmol/L) and total cholesterol levels (5.41 +/- 0.20 vs 6.48 +/- 0.29 mmol/L) than the NV elderly women (P less than 0.01) for each. The V elderly women tended to have less body fat and midupper arm muscle area than the NV. No differences between groups were found in a variety of metabolic and electrocardiographic parameters during graded maximal treadmill testing except for lower heart rates in the V women. VO2max was not significantly different between the V and NV elderly women (23.8 +/- 1.5 vs 21.9 +/- 0.8 ml.kg-1.min-1, respectively). In summary, when healthy elderly V women are compared with closely matched NV peers, the vegetarian diet is associated with several benefits, primarily lower blood glucose and lipid levels, but not greater functional capacity.

Aged↗
PubMed1989

In vitro NMR evaluation of human thyroid lesions.

In vitro analysis of spin-lattice relaxation times (T1), water self-diffusion coefficients (DH2O), and proton NMR spectroscopy were performed in a study of 88 patients with thyroid lesions in order to determine the usefulness of these parameters in the differentiation of benign and malignant tissues. Thyroid tissue sample proton NMR spectral patterns were examined at 360 MHz. Proton NMR spectra were different for normal thyroid tissues, benign, and cancerous lesions. Significantly prolonged T1 (0.5T) and decreased DH2O were found in cancerous thyroid lesions relative to normal thyroid tissues. Considerable overlap was found, however, in comparing T1 and DH2O values for benign and malignant thyroid lesions. This study suggests that proton NMR spectroscopy may be more useful than T1 and DH2O in differentiating benign and malignant thyroid lesions.

Adenoma↗
PubMed1989

Increased frequency of posttransplant lymphomas in patients treated with cyclosporine, azathioprine, and prednisone.

We have documented seven B cell lymphomas over a six-month period in 132 (5.3%) kidney and heart allograft recipients immunosuppressed with cyclosporine, azathioprine, and prednisone (triple therapy). This is a significant increase (P less than 0.0001) over the number of such tumors seen by us previously. Only 2 lymphomas had occurred in 669 cadaver and 29 living-related kidney allografts treated with azathioprine and prednisone alone (0.3%). In 160 cadaver kidney recipients treated with cyclosporine and prednisone there have been no lymphomas. Similarly in 14 living-related kidney recipients who were transplanted since the introduction of triple therapy for cadaver grafts, but continued to receive only azathioprine and prednisone, no lymphomas occurred. There seemed to be a clear relationship between this increase and the use of triple therapy. This led us to examine other possible contributing factors. A case control study has not shown any other factor that differs in patients in whom lymphomas developed. We have only been able to demonstrate Epstein Barr virus nuclear antigen in the cells of one tumor. Four of these 7 tumors were monoclonal, one polyclonal, and two indeterminate. All patients had their immunosuppression withdrawn and six received intravenous acyclovir. Three patients have shown some response but four patients died. Triple therapy is being used by many centers to reduce the level of cyclosporine toxicity. We wish to sound a note of caution that this may result in an increased incidence of posttransplant lymphomas.

Adult↗
PubMed1989

Improved diagnosis of Becker muscular dystrophy by dystrophin testing.

We assessed the quantity (relative cellular abundance) and quality (approximate molecular weight) of dystrophin in muscle biopsies from 97 patients with a diagnosis of possible Becker muscular dystrophy. Fifty-four (all male) had dystrophin abnormalities and were deemed to have true Becker muscular dystrophy. The other 43 patients (14 female, 29 male) had no detectable dystrophin abnormalities. Of the dystrophin-verified Becker dystrophy patients, 35% (19/54) had a family history consistent with X-linked recessive inheritance. On the other hand, none of the 43 patients with apparently normal dystrophin had a clear X-linked family history, suggesting that few of these 43 actually had a form of Becker dystrophy. The data suggest that of all patients with a clinical picture consistent with Becker dystrophy but no family history, about 60% will be true Becker patients. The correlation of both the biochemical and clinical data suggests that Duchenne/Becker dystrophy can be divided into 4 clinically useful categories: Duchenne dystrophy (wheelchair at about age 11 years; dystrophin quantity less than 3% of normal); severe Becker dystrophy (wheelchair age 13 to 20 years; dystrophin 3% to 10%); and moderate/mild Becker dystrophy (wheelchair greater than 20 years; dystrophin quantity greater than or equal to 20%). Given the observed clinical variability of Becker dystrophy, it appears that dystrophin analysis is required for accurately distinguishing between Becker dystrophy and clinically similar autosomal recessive myopathies.

Adolescent↗
PubMed1989

Lead toxicity and iron deficiency in Utah migrant children.

We determined the frequency of presumptive iron deficiency and lead toxicity in 198 Utah migrant children, ages 9-72 months, during the summer of 1985. There were no confirmed cases of lead toxicity. Thirteen per cent of those tested and 30 per cent of the children ages 9-23 months were iron deficient. Hematocrit determinations accurately predicted iron deficiency in only 35 per cent of the children confirmed to have this disorder via erythrocyte protoporphyrin screening.

Anemia, Hypochromic↗
PubMed1989

Outflow resistance of enucleated human eyes at two different perfusion pressures and different extents of trabeculotomy.

Aqueous outflow resistance of enucleated human eyes was measured at 7 and 25 mm Hg before and after partial and complete (12 clock hours) internal trabeculotomy. Following complete trabeculotomy, 71% of the resistance was eliminated at 25 mm Hg while only 49% was eliminated at 7 mm Hg. In contrast to published findings in eyes with intact trabecular meshwork where the resistance increased with increasing IOP (1), following complete trabeculotomy, the resistance decreased 2% per mm Hg with increasing IOP. Experiments with trabeculotomy limited to part of the circumference showed that a one hour trabeculotomy produced 41% (25 mm Hg) to 60% (7 mm Hg) of the effect of a twelve hour trabeculotomy. The results indicate that a surprisingly high fraction of aqueous outflow resistance resides in the distal aspects of the outflow system at normal IOP, and that this distal resistance drops as IOP is increased.

Aged↗
PubMed1989

Give me a break--benefits of a caregiver support service.

Caregivers of elderly adults experience problems with self-image, stress levels, and the patient-relative relationship. Caregivers often receive relief only when the elderly adult is hospitalized. This study found a reduction in anxiety and suspicious behavior in caregivers, but helplessness was not reduced. Regular psychological evaluation may provide warning signs of the need for a period of relief for the caregiver. Further research is needed to determine which specific behaviors result in high stress for caregivers.

Aged↗
PubMed1989

Chart reading and anxiety levels of nursing students prior to first interactions with psychiatric clients.

Nursing students' anxiety levels on the first day of their psychiatric clinical experience were compared between those students who were assigned to read (N = 58) or not read (N = 60) the client's chart prior to the first nurse-client interaction. Students' trait and state anxiety levels were measured at the beginning of the day. State anxiety levels were measured again after students were given instructions to read or not read the client's chart. Using trait and the first measure of state anxiety as covariates, there was no significant difference in the state anxiety scores between readers and non-readers. Based on anxiety theory, it was concluded that being told to read/not read the psychiatric client's record prior to the first interaction with the client, does not significantly influence the student's state anxiety level. Thus, when nurse educators are planning the psychiatric experience, they may wish to allow the student to make the decision whether to read or not read the client's chart, after being told the advantages and disadvantages of this action.

Anxiety↗
PubMed1989

Aldose reductase inhibitors and prevention of galactose cataracts in rats.

Our previous studies have shown that the aldose reductase inhibitor (ARI), sorbinil, prevents galactose-induced alterations and cataracts in rat lenses. We have now used sorbinil as well as another ARI, Eisai compound E-0722, to determine their potency in inhibiting aldose reductase- and galactose-induced alterations in lens morphology and Na+-K+-ATPase activity. Young Sprague Dawley rats were fed Purina Rat Chow plus 50% galactose, with or without 15 mg sorbinil, 0.15, 0.5 or 1.0 mg of E-0722/kg body weight per day. Controls were given Purina Rat Chow with or without ARIs. Lenses were studied for up to 60 days following the initiation of the diet using morphological, cytochemical and biochemical approaches to assess any alterations in the lens. While galactose-induced damage and cataracts were delayed by low doses (0.15 mg and 0.5 mg) of E-0722, they were completely prevented by the administration of 15 mg of sorbinil or 1 mg of E-0722/kg body weight per day. This study further showed that just 1 mg of E-0722 was more effective in preventing cataracts than 15 mg sorbinil. Thus it appeared that E-0722 was a more potent inhibitor of aldose reductase than sorbinil.

Aldehyde Reductase↗