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Biomedical subjects

D Zimmerman

Publications and source records attributed to D Zimmerman.

16 recordsLinked to original sources
PubMed1992

Radiation therapy for diabetes insipidus caused by Langerhans cell histiocytosis.

Hypothalamic-pituitary radiation therapy has been the standard treatment for the diabetes insipidus of Langerhans cell histiocytosis. The goal of this study was to assess the role of radiation therapy in Langerhans cell histiocytosis-associated diabetes insipidus and to compare the results with nonirradiated controls. Forty-seven patients with pathologically confirmed Langerhans cell histiocytosis were diagnosed with diabetes insipidus between 1950 and 1989 and were treated at the Mayo Clinic. These patients were divided into two groups on the basis of treatment for the diabetes insipidus: The first group (radiation group) included 30 patients (28 of whom were evaluable for response) who received hypothalamic-pituitary radiation therapy, and the second group (control group) included 17 patients who did not. A partial response to treatment was defined as a reduction in vasopressin dosage or improvement in computed tomography (CT) or magnetic resonance imaging (MRI). A complete response was defined as no further need for vasopressin therapy or normalization of CT or MRI. End points analyzed included treatment response, patient characteristics, morbidity, dose-response relationship, and survival. Patient characteristics of the two groups were similar except for age and lung involvement, both of which were significantly less in the radiation group. Thirty-six percent of patients (10 of 28) in the radiation group responded to hypothalamic-pituitary radiation therapy (22% complete response and 14% partial response), whereas none in the control group responded. Five of the six complete responders were irradiated within 14 days of the diagnosis of diabetes insipidus. The mean dose used in the responding and nonresponding patients was 11.2 and 10 Gy, respectively. Three of five patients (60%) treated with more than 15 Gy responded compared to seven of 23 (30%) treated with less than 15 Gy. Eight of the 10 responders (80%), compared to 16 of 35 nonresponders (46%), were female. Only one in 20 patients with concomitant lung histiocytosis responded. Complications of therapy may include insufficiency in other hypothalamic-pituitary axes in the treated patients. Actuarial survivals at 5, 10, 20, and 40 years for the entire group were 80%, 78%, 75%, and 65%, respectively, with a median follow-up in living patients of 14.7 years.

Adolescent↗
PubMed1992

Tibia vara in a patient with Bardet-Biedl syndrome.

The Bardet-Biedl syndrome is characterized by polydactyly, hypogonadism, obesity, mental retardation, and retinitis pigmentosa. Several other skeletal findings include hip dysplasia, short stature, and skull deformities. The patient described in this report has the classic findings of Bardet-Biedl syndrome in conjunction with tibia vara and irregular physes of the lower extremities.

Abnormalities, Multiple↗
PubMed1991

Limitations of the countershock dose response: a study of transthoracic current.

Dose response assessment of countershock efficacy has been widely determined with respect to energy but not current. The purpose of this study was to examine the utility of the dose response method in a current-based model of transthoracic defibrillation (pentobarbital anesthetized dogs, n = 8). Ventricular fibrillation induction lasting 15 seconds was separated by 5-minute intervals. Current defibrillation threshold (DFT; the lowest current that successfully defibrillated) was determined by decreasing current on successive trials. Energy DFT equaled the energy value of the corresponding current DFT. Subsequent data were expressed in normalized terms with each DFT assigned a normalized value of 1.00. Three shocks were delivered in random order at each of seven normalized current nodes (total of 21 shocks): 0.55, 0.70, 0.85, 1.00, 1.15, 1.30, and 2.00 x DFT (early testing). Randomization was repeated, and a second set of 21 trials were performed (late testing). Composite plots were made relating normalized current and energy to the percent successful defibrillation. The dose response expressed in normalized energy demonstrated an overall shift to the left compared to current. The difference was significant at every node value below the estimated DFT. Ninety percent of successful trials with respect to current and energy occurred at or above 0.85 DFT and 0.55 DFT, respectively. Significant changes in impedance occurred between early testing (60 +/- 6 ohms) and late testing (47 +/- 5 ohms), n = 8, mean +/- SD. Current, compared to energy, is a more accurate parameter in the dose response assessment of transthoracic defibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1979

H-Y antigen. Cell surface mapping and testosterone-induced supramolecular repatterning.

Previous work with the antibody-blocking technique showed that the map of surface components for thymocytes prefixed with paraformaldehyde is the same as the map for unfixed thymocytes, with the following exception: after exposure to anti-TL or anti-Db, TL and H-2Db occupy adjacent positions on unfixed cells but not on fixed cells. This was interpreted as an indication that activation of particular components of the surface phenotype initiates ordered changes in the display of cell-surface molecules, approximation of TL and Db in this instance. These studies have now been extended to the H-Y component on the surface of male cells. On fixed male mouse thymocytes, H-Y lies adjacent to TL and relatively distant from H-2Db, H-2Kb, H-2Lb, Lyt-1.2, and Lyt-2.2. However, on unfixed male mouse thymocytes, similarly exposed to H-Y antibody, H-Y and H-2Db are adjacent. Presumably, this engagement of H-Y sites by H-Y antibody brings H-Y and H-2Db together. Evidence that this change in pattern may be physiologically relevant comes from the finding that testosterone, but not estradiol, caused the same selective approximation of H-Y and H-2Db.

Animals↗
PubMed1979

Hypnosis.

Explore the source record for details and available documents.

Attitude of Health Personnel↗
PubMed1979

Surface mapping of mouse thymocytes.

The blocking method used previously for determining the relative positions of different components of the cell surface was modified by first fixing the cells with paraformaldehyde. This technique was applied to the H-2K (K), H-2D (D), TL, Lyt-1, and Lyt-2 surface components of mouse thymocytes, and the results were compared in parallel with data obtained with the original technique with unfixed cells. Previous mapping data with unfixed cells, indicating the positions of these molecules relative to one another, were confirmed with paraformaldehyde-fixed cells, with one exception. On unfixed cells, D and TL appeared sufficiently adjacent to produce mutual interference in the attachment of anti-D and anti-TL antibodies. With paraformaldehyde-fixed cells this was not so, D and TL appearing sufficiently separated from one another to obviate interference in the attachment of anti-D and anti-TL antibodies. The previously reported close association of K with Lyt-1 and of D with Lyt-2 were demonstrable equally with unfixed and paraformaldehyde-fixed thymocytes. It is suggested that activation of D sites, and alternatively of TL sites, by antibody in the present experiments brings these two molecules into apposition and that this movement may exemplify a mechanism concerned in immunological recognition and response.

Animals↗
PubMed1978

Qa-2 and Qa-3 antigens on lymphocyte subpopulations. I. Mitogen responsiveness.

The effects of anti-Qa-2 plus C and anti-Qa-3 plus C on mitogen-induced proliferation were studied. Both of these antisera in the presence of C markedly reduced both Con A- and PHA-induced proliferation while having little or no effect on LPS-induced proliferation. LPS, Con A, and PHA cultures and cultures containing media alone, examined at 72 hr, contained high proportions of Qa-2+ and Qa-3+ cells.

Animals↗
PubMed1977

The Tla locus: a new allele and antigenic specificity.

Four of 23 H-2 alloantisera screened for anti-TL activity contained such activity. One of these alloantisera, D-35, defined a new TL specificity, TL.5, and a new Tla allele, Tlad. TL.5 has all the characteristics of a TL antigen and has a different strain distribution than previously known ones. This new complexity at the Tla locus and the previous finding of other serologically defined genes in the Tla region indicate that this genetic region cannot be ignored in analyzing antisera produced in strains made congenic for the major histocompatibility complex.

Alleles↗
PubMed1976

Bacterial endocarditis in a patient with Marfan's syndrome.

A patient with Marfan's syndrome and subacute bacterial endocarditis is presented. Echocardiographic studies demonstrated dilatation of the aortic root, prolapse of the posterior leaflet of the mitral valve, and the appearance of shaggy echoes on the anterior miltral leaflet, of the kind previously described as representing bacterial vegetations.

Adult↗
PubMedDate not supplied

Somatomedin C/insulin-like growth factor I levels after treatment of acromegaly.

An in-house method was used, including dissociation of Somatomedin C/insulin-like Growth Factor I (Sm-C/IGF-I) binding proteins with acid and extraction of Sm-C/IGF-I by C-2 cartridge before radioimmunoassay, to measure plasma Sm-C/IGF-I levels in three groups of patients--total of 19--with acromegaly who underwent transsphenoidal removal of pituitary tumors. In group A (n = 7), the Sm-C/IGF-I levels did not decrease to normal on postoperative day 1 even though the growth hormone concentration had decreased to normal. In group B (n = 4), the Sm-C/IGF-I level decreased to normal in three of the four patients on postoperative day 4, but it remained elevated in one. At two months postoperatively, all four patients had normal values. Group C patients (n = 8) had had an operation two to 23 years previously, and all remained in remission with normal Sm-C/IGF-I levels. Our findings indicate that the Sm-C/IGF-I assay is useful for monitoring acromegaly after transsphenoidal removal of pituitary tumors, but it should be ordered at least four days postoperatively.

Acromegaly↗