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S Dean

Publications and source records attributed to S Dean.

At least 37 records · Page 2Linked to original sources
PubMed1996

Cushing's syndrome and hypothalamic-pituitary adrenal axis suppression induced by medroxyprogesterone acetate.

The referral of a patient with features of Cushing's syndrome but with suppressed plasma cortisol and adrenocorticotrophic hormone concentrations prompted us to study the effect of medroxyprogesterone acetate (MPA) therapy on the adrenal axis. 11 women (aged 54-82 years) who were receiving 200-400 mg/day MPA were studied. Of these, four had subnormal plasma cortisol responses to a short synacthen test, and two more had borderline responses (30 min post-synacthen plasma cortisol results of 411 and 511 nmol/L). We conclude that suppression of the adrenal axis occurs relatively frequently in patients on MPA and that such patients should be checked for evidence of suppression before MPA therapy is withdrawn.

Aged↗
PubMed1996

The use of noninvasive respiratory muscle aids in the management of patients with progressive neuromuscular diseases.

Most patients with primarily ventilation impairment can use noninvasive alternatives to tracheostomy for long-term ventilatory support and airway secretion management. The most important and versatile method of noninvasive ventilatory support is mouthpiece intermittent positive pressure ventilation. Mouthpiece intermittent positive pressure ventilation also can be used via a Lipseal for nocturnal support. The intermittent abdominal pressure ventilator is an option for daytime aid, and nasal intermittent positive pressure ventilation is usually preferred for nocturnal support. Manually assisted coughing and mechanical insufflation-exsufflation can be critical for airway secretion elimination.

Humans↗
PubMed1992

Morphometric analysis on myocardial injury related to the use of high volume potassium cardioplegic solution during ischemic arrest.

We correlated the effects of high volumes of K+ cardioplegic solution on myocardial structure and function in 16 dogs following open-heart surgery. Eight animals received high volume potassium cardioplegic solution (25 cc/kg body weight, every 30 min) during 90 min of ischemic arrest (HVK-C group). The others received sufficient cardioplegic solution to maintain complete electrical arrest as defined by voltage monitoring criteria (VM group). Cardiac index (CI), left ventricular stroke work index (LVSWI), and myocardial contractility (dp/dt) were determined before arrest and after 90 min of ischemia and 45 min of reperfusion. Biopsies were taken for EM ultrastructure and ATP estimation. Morphometric analysis of EM micrographs found increased volume of damaged mitochondria (DMR) (p less than 0.025), damaged myofibrils (DMF) (p less than 0.001), intermyofibrilar edema (p less than 0.005), T-tubule and sarcoplasmic reticulum (p less than 0.05) in the HVK-C group. Left ventricular (LV) function was more depressed in animals receiving HVK-C. CI decreased by 1.8 +/- 0.4 l/min/square meter (p less than 0.01), LVSWS fell by 3.3 +/- 0.8 gm-m/beat/Kg (p less than 0.01), dp/dt decreased by 684 +/- 135 (p less than 0.0025). ATP decreased by 26% in HVK-C and by 12% in VM group (0.1 less than p less than 0.05). Structural damage (scores of injured volume of mitochondria and myofibrils) correlated with post-ischemic depression of LV function (Cardiac output and myocardial contractility), r = -0.72 and -0.66 (p less than 0.001 and 0.004).

Adenosine Triphosphate↗
PubMed1992

The relationship of mast cells and their secreted products to the volume of fibrosis in posttransplant hearts.

A series of 96 posttransplant endomyocardial biopsies taken from 11 patients was subjected to quantitative analysis of mast cells and fibrosis. Ultrastructural analysis showed that mast cell numbers were increased and there was obvious degranulation in some posttransplant hearts. Activated mast cells and their secreted products, which contain heparin and histamine, are toxic to the hearts and may contribute to interstitial and perimyocytic fibrosis. The numbers of mast cells and granules were correlated with volume of fibrosis (r = 0.63, P less than 0.025; r = 0.73, P less than 0.01). There were differences between the release of mast cell granule contents seen in the posttransplant hearts and the rapid and massive reaction of anaphylactic degranulation of mast cells. Some mast cells progressively lost their dense granule contents, displaying a variety of piecemeal degranulation that indicates a slow degranulation process. These events occurred from the first week; they lasted from weeks to months. The fibrosis developed quickly in the cases with more mast cells and degranulation. The cases with fewer mast cells and granules showed only mild increases in the volume of fibrosis. Mast cells appeared as early as the first posttransplantation week. Patients with greater numbers of mast cells underwent more severe rejection episodes. This study demonstrated that mast cells play an early and important role in the perimyocytic and interstitial fibrosis of posttransplant hearts. Mast cells may also be important in the inflammatory process of rejection reaction. The severity of fibrosis appears related to the density of mast cells and their granules.

Fibrosis↗
PubMed1992

Comparative epidermal Langerhans cell migration studies in epidermal and epidermal/dermal equivalent grafts.

Immigration of Langerhans cell precursors from the peripheral blood to the skin was studied in human grafts placed on severe combined immunodeficient (SCID) mice. Monocyte fractions of human blood were injected intraperitoneally to SCID bearing either reconstituted (Langerhans cell free) epidermal sheets (E) or living skin equivalents (E/D) consisting of both epidermis and dermis. A range of immunocytochemical and ultrastructural markers was employed to monitor the colonization of the grafts, i.e., CD1a/c, Birbeck granules. In situ hybridization with probes against Alu sequences of human DNA were employed together with immunostaining for MHC class I mouse and human antigens to document graft survival. Although unequivocal LC were detected within E grafts, including both human (CD1a positive) and murine (NLDC-145 positive), no migration was achieved in the E/D situations.

Animals↗
PubMed1992

Elimination of matrix effects in electrothermal atomic absorption spectrophotometric determinations of bismuth in serum and urine.

A sensitive and precise electrothermal atomic absorption spectrophotometric method for determining bismuth concentration is described. Protein precipitation and the use of a palladium modifier reduce the problems of foaming and permit the use of a higher ashing temperature. The detection limit of the assay is 0.9 nmol/L. Total CVs (intra- and interassay) for serum ranged from 3.5% to 15.1% and for urine from 4.8% to 14.5% at concentrations of 60.0 and 6.0 nmol/L, respectively. Analytical recoveries of bismuth added to serum and urine were 102% and 103% over the same range. The method is robust and reproducible and can be accurately calibrated with aqueous standards.

Adult↗
PubMed1991

Immunoalkaline phosphatase with cerium-based cytochemistry for double staining at the transmission electron microscopic level.

Immunoelectron microscopic localization of surface antigens on lymphocytes is possible using alkaline phosphatase combined with cerium-based cytochemical methods. Distinctive electron-dense deposits are easily identified at sites of antibody binding. Mouse splenocytes showing surface immunoglobulin localization and human peripheral blood lymphocytes stained for the MHC-Class II antigen HLA-DR illustrate the results. Double staining for murine Ia antigen by the alkaline phosphatase procedure, combined with immunogold labeling of antigens identified on dendritic cells, i.e., NLDC-145, demonstrates the utility of the cerium cytochemical method.

Alkaline Phosphatase↗
PubMed1991

An assessment of population-based and Bayesian methods to individualize digoxin doses shortly after the start of therapy for atrial fibrillation.

The accuracy of population-based methods and of Bayesian analysis to predict individual digoxin pharmacokinetic variables have been evaluated by their ability to predict a measured peak and trough serum digoxin concentration. We studied 13 digitalized patients (three women) whose mean (range) age and weight was 65.8 (60-78) years and 76.6 (68-101.6) kg and who had stable renal function. The population-based methods (using a clearance of 48.87 + 0.87 x creatinine clearance in ml/h/kg and volume of distribution, in litres, of either 7.3 x weight (kg) or 269 + 3.12 x creatinine clearance) were more than adequate for clinical purposes. The mean prediction errors of a measured steady-state peak concentration from these two population methods were -0.074 and 0.013 microgram/l respectively, whilst those of a measured trough concentration were -0.058 and 0.005 microgram/l. Bayesian analysis, using a sample drawn 11 h after the dose on day five of therapy, gave overall the least biased and most precise of the revised estimates. The mean prediction errors of peak and trough values using this sample were 0.069 and -0.005 microgram/l respectively. As expected, the closer the sample was drawn to the time of the trough concentration the more precise were the Bayesian-derived predictions. The value of the Bayesian technique to individualize digoxin doses could not be validated because it was not possible to distinguish between this and the population methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Effects of statutes requiring psychiatrists to report suspected sexual abuse of children.

OBJECTIVE: Reporting of child sexual abuse is mandatory in all 50 states. Conceptual distinctions between privileged communications and mandatory reporting are reviewed, and the impact of recent changes in Maryland's reporting laws is examined. METHOD: Beginning in 1964 Maryland law required reporting if abuse was suspected when a physician examined a child. In 1988 reporting of disclosures by adult patients about child sexual abuse that occurred while they were in treatment was mandated. In 1989 all patient disclosures, even about such abuse that occurred before treatment, became reportable. During the period of statutory changes, the Johns Hopkins Sexual Disorders Clinic had kept track of adult patients who referred themselves for treatment and adult patients' disclosures of child sexual abuse. This allowed analysis of the impact produced by changes in the reporting requirements. RESULTS: 1) Mandatory reporting of disclosures about prior child sexual abuse deterred undetected adult abusers from entering treatment. The rate of self-referrals when such reporting became mandatory in 1989 dropped from approximately seven per year (73 over a 10-year period) to zero. This may have caused some unidentified children to remain at risk. 2) Mandatory reporting deterred patients' disclosures about child sexual abuse that occurred during treatment. In 1988 the disclosure rate during treatment dropped from approximately 21 per year to zero. This deprived clinicians of information important for early intervention. 3) Mandatory reporting failed to increase the number of abused children identified. The number identified secondary to such disclosures was zero. CONCLUSIONS: Optimal protection of children, as well as treatment for adult patients, may be better accomplished by legislation that supports options other than reporting.

Adult↗
PubMed1990

Tail docking.

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Animal Welfare↗