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Biomedical subjects

M Ziegler

Publications and source records attributed to M Ziegler.

At least 217 records · Page 12Linked to original sources
PubMed1990

Value of selective reversible sacral nerve blockade in the diagnosis and treatment of the urge syndrome.

Interstitial cystitis, neurogenic disturbances of bladder emptying resulting from incomplete supranuclear lesions and idiopathic detrusor hyperreflexia are clinically always associated with frequency, nocturia, urgency or urgency incontinence (urge syndrome). These disturbances of bladder emptying are difficult to distinguish, even urodynamically. With selective sacral nerve blockade, it is possible to differentiate between forms urodynamically using a nerve-blocking anesthetic. Reversible selective sacral nerve blockade is also the treatment for idiopathic detrusor hyperreflexia.

Adult↗
PubMed1990

Effects of salt, race, and hypertension on reactivity to stressors.

Blood pressure and heart rate reactivity to a psychological stressor and to a cold pressor test were examined in a group of 51 normotensive and 37 unmedicated hypertensive men. All were studied twice, once while the participants were maintained on a moderately high salt (200 meq sodium/day) diet and once while the participants were maintained on an extremely low salt (10 meq sodium/day) diet. Dietary salt had no effect on blood pressure or heart rate responses to the two stressors. The systolic and diastolic responses of the white participants to the psychological stressor were greater than those of the black participants (both p less than 0.05); however, there was no difference between blacks and whites in reactivity to the cold pressor challenge. As compared with the normotensive group, the hypertensive group reacted to the psychological stressor with increased responses in systolic blood pressure, diastolic blood pressure, and heart rate (all p less than 0.05). The hypertensive group also hyperresponded in terms of the systolic pressure response to the cold pressor task (p less than 0.05). Plasma norepinephrine and epinephrine responses were not significantly different across the two diets, races, or diagnoses.

Adult↗
PubMed1990

Plasma norepinephrine kinetics, dopamine-beta-hydroxylase, and chromogranin-A, in hypothyroid patients before and following replacement therapy.

Whether the increased plasma norepinephrine level reported in hypothyroidism is the result of impaired norepinephrine (NE) clearance or increased NE release by nerve terminals is unknown. We, therefore, measured plasma NE levels and clearance in 11 hypothyroid patients before [T4 index, 41.2 +/- 7.7 nmol/L (mean +/- SEM); TSH, 71.4 +/- 23.0 mU/L] and 4 +/- 0.5 months after thyroid replacement (T4 index, 136.4 +/- 24.4 nmol/L; TSH, 3.2 +/- 1.2 mU/L) and in 8 healthy volunteers. Plasma dopamine-beta-hydroxylase and chromogranin-A, which are coreleased with NE by sympathetic nerve endings, were also measured. Plasma NE was higher in the hypothyroid (2.37 +/- 0.24 nmol/L) than in the euthyroid state (1.86 +/- 0.24 nmol/L; P less than 0.02) or in the controls (1.87 +/- 0.27 nmol/L). Plasma clearance of NE, however, was not affected after thyroid replacement (hypothyroid, 2.08 +/- 0.31 L/min; euthyroid, 1.94 +/- 0.21 L/min; controls, 1.86 +/- 0.15 L/min). There was no significant change in plasma dopamine-beta-hydroxylase (hypothyroid, 720 +/- 139 nmol/mL.h; euthyroid, 553 +/- 97 nmol/mL.h) or plasma chromogranin-A (hypothyroid, 48.9 +/- 7.1 ng/mL; euthyroid, 42.9 +/- 5.3 ng/mL) after thyroid replacement. We conclude that the increased plasma NE in hypothyroid patients is not due to a change in plasma clearance, but is more likely secondary to increased NE release.

Adult↗
PubMed1990

Decreased sensitivity to alpha-adrenergic stimulation in hypothyroid patients.

Nine hypothyroid patients had blood pressure and pulse rate responses to the alpha-adrenergic agonist phenylephrine measured before [T4 index, 45.045 +/- 9.009 nmol/L (mean +/- SEM); TSH, 57.1 +/- 23.6 mU/L] and after 4 +/- 0.5 months of thyroid replacement therapy (T4 index, 141.570 +/- 29.601 nmol/L; TSH, 2.6 +/- 1.0 mU/L). Hypothyroid patients had a smaller blood pressure increment and heart rate decrement at both 66.7 and 100 micrograms/min infusion rates of phenylephrine. Furthermore, the slope of the dose-response curves for systolic (2.06 +/- 0.22 vs. 1.32 +/- 0.19; P less than 0.01) and diastolic (1.04 +/- 0.18 vs. 0.62 +/- 0.08; P less than 0.01) blood pressures were significantly greater after thyroid replacement therapy. Pulse rate changes remained proportional to blood pressure changes in hypothyroid patients, so there was no change in baroreflex sensitivity. Plasma norepinephrine levels were higher before than after thyroid replacement (2.41 +/- 0.28 vs. 1.82 +/- 0.29 nmol/L, respectively; P less than 0.01). Thus, hypothyroid patients have diminished pressor sensitivity to an alpha-adrenergic agonist and increased plasma levels of the alpha-adrenergic neutrotransmitter norepinephrine.

Adult↗
PubMed1990

Selecting language-impaired children for research studies: insights from the San Diego Longitudinal Study.

The need for a standardized approach to the selection of research subjects for studies on language impairment has long been an area of controversy in the literature. The data obtained from the selection of language-impaired and control subjects for the San Diego Longitudinal Study allows one to evaluate the effects a two-stage subject-selection procedure has on the characteristics of the language-impaired and normal subjects selected for research studies. Specifically, what effect do quantitative measures, as compared to clinical judgements and referrals, have on the characteristics of subjects selected for research studies? Explicit and detailed oral and written descriptions of subjects sought for both a language-impaired group and a control group were given to teachers and clinicians. However, only 39 of the first 100 children referred as language-impaired and 29 of the first 60 referred as normal controls were found on standardized testing to meet the study criteria and to be matched on important variables, such as IQ and socioeconomic status. These results demonstrate the importance of establishing quantitative inclusionary as well as exclusionary criteria for selecting and matching subjects in clinical research studies.

Child, Preschool↗
PubMed1990

Beta-adrenergic receptor sensitivity during sodium restriction and converting enzyme inhibition.

Adding converting-enzyme inhibitors to the salt depleted state is marked by a reduction in blood pressure despite compensatory increases in heart rate and plasma norepinephrine. This study investigated whether this increase in sympathetic function is also accompanied by an increase in beta-adrenergic receptor function. Ten subjects were studied following two separate five day hospitalizations on 10 mEq sodium diets while receiving either placebo or captopril. During low sodium with captopril, blood pressure and angiotensin II decreased, while heart rate, renin, norepinephrine and isoproterenol-stimulated cyclic AMP accumulation in lymphocytes increased. The results indicate that enhanced beta-adrenergic receptor function does accompany sympathetic activation during sodium restriction and converting enzyme inhibition and further support studies showing that the renin-angiotensin system plays the dominant role in blood pressure regulation in the sodium depleted state.

Adult↗
PubMed1990

[Binding of monoclonal antibodies to an insulin-producing rat tumor cell (RIN) after partial cell synchronization].

Murine monoclonal antibodies against pancreatic islet cell antigens were generated by somatic cell hybridization and their binding to the insulin-producing rat insulinoma cell line (RIN-5 AH) was evaluated in an indirect immunofluorescence test. An ascites dilution of 1:50 was used for immunostaining using RIN cells harvested from monolayer cultures in RPMI 1640 supplemented with 7.5% fetal calf serum (controls) or test cultures supplemented with 10 mmol/l hydroxyurea to collect the cells in G1/S phase. The five mc-ICSA tested showed a wide variety in their individual binding from 95 up to 30% but their binding was not influenced by hydroxyurea use for synchronization. The antigenic determinant recognized by the anti-glucolipid mc-ICSA 56a F3 was not present on all RIN-5 AH cells. In average, only 35% of the RIN cells showed a striking binding of the monoclonal 56a F3.

Animals↗
PubMed1990

Detection of antibodies to islet cell and splenic lymphocytes in diabetes-prone BB and adjuvant-streptozotocin treated Lewis rats by ELISA and immunoblot analysis.

An enzyme-linked immunosorbent assay (ELISA) has been developed to detect antibodies against surface components of rat islet and spleen lymphocytes. Live islet tumor RIN5 AH cells expressing characteristic ganglioside target antigens or rat spleen cells were immobilized onto wells of microtiter polystyrene plates precoated with poly-l-lysine and then incubated with test or normal rat sera. Cell surface-bound antibodies were quantitated after reaction with horseradish peroxidase-conjugated rabbit anti-rat Ig. With this assay, 46% (6/13) of sera from diabetes-prone BB rats and 100% (8/8) of sera from rats treated with complete Freund's adjuvant/streptozotocin (CFA/STZ) prior to immunization with RIN cells had islet cell surface antibodies: 54% (7/13) and 75% (6/8), respectively, were positive for lymphocyte antibodies (defined as the HRP anti-rat Ig binding exceeding the mean + 2SD of control group values). SDS polyacrylamide gel electrophoresis followed by immunoblotting analysis suggested that the islet cell antibodies in sera from the BB and CFA/STZ rats recognized RIN-cell components that were different in their molecular weights. These antigens were not detectable on spleen cells indicating that the ELISA described can be used to quantitate levels of islet cell specific antibodies which possibly reflect beta cell damage with progression to islet degeneration in the rat.

Animals↗
PubMed1990

Characterization of the F(ab')2 and Fab' fragments prepared from a mouse monoclonal insulin antibody.

In this report, optimum conditions were determined for the production of immunoreactive fragments from a mouse monoclonal insulin antibody, and their immunochemical characterization is described. Stable fragments can be obtained in good yield from the purified IgG 1, first by cleavage with pepsin and then by reducing the disulfide bonds with cysteine and subsequent alkylation with iodoacetamide. F(ab')2 and Fab' fragments having molecular weights (Mr) of about 108,000 (108 K) and 55 K, respectively, were produced. Ligand binding assay as well as indirect immunofluorescence on mouse pancreas section demonstrated their reactivity with free and tissue-bound insulin antigen. These results provide methods for the production and characterization of defined fragments of insulin antibody useful in experiments where non-specific interactions mediated by the Fc portion of the whole immunoglobulin may occur.

Animals↗
PubMed1990

[The value of corpus cavernosum sonography following administration of vasoactive substances in the diagnosis of patients with erectile impotence].

In 70 Patients with erectile dysfunction, ultrasound examination of both corpora cavernosa after intracavernous injection of papaverine was done using B-scan, Duplex scan and Doppler color. B-scan can detect morphological disease in a penis profundis, the higher degrees of cavernous muscle myopathia, and disease of the tunica albuginea. For the analysis of pulse curve and the measurement of blood-flow velocity, the Duplex scan is necessary. Doppler color imaging enables ultra sonographic examination of a dorsalis and a penis profundis and can detect intracavernous vascular pathology. The results show that ultrasonography is an important diagnostic tool in patients with erectile dysfunction. A differentiated therapeutic strategy can be based on this examination, especially when revascularization procedures are being discussed. Additionally, better follow-up of patients under self-injection therapy is possible.

Adult↗
PubMed1990

Renin correlates with blood pressure reactivity to stressors.

This study examines the relationship between renin levels and physiologic reactivity to stressors. Seventy-five normotensive and mildly hypertensive men were studied on a high salt diet (200 mEq/day Na) and on a low salt diet (10 mEq/day Na). Renin, plasma catecholamines, heart rate, and blood pressure were examined at rest, after standing in place for 8 minutes, and after a brief mathematics task. Renin levels increased in response to the stressor tasks, particularly on the low salt diet. The change in diastolic pressure in response to the stressor tasks was correlated with the change in renin (r = 0.45, p less than 0.001) but not with the change in norepinephrine. The combination of change in renin and norepinephrine levels accounted for 21% of the variance in predicting diastolic pressure reactivity (p less than 0.0015).

Adult↗
PubMed1990

[Super-selective embolization of a kidney angioma].

Superselective embolization of a centrally situated renal arteriovenous angioma in a 68-year-old woman is reported. The cardinal symptom was a recurrent painless gross hematuria, which disappeared after treatment. The embolization technique and the results of a 7-month follow-up examination are described.

Aged↗
PubMed1989

Adenosine formation by isolated rat kidney mitochondria.

Isolated rat kidney mitochondria are able to generate extraordinary amounts of adenosine. About one-third of the adenosine formed only results from the degradation of adenine nucleotides. Pyridine nucleotides may contribute to adenosine formation. Nevertheless, there must be an additional, as yet unidentified, acid-insoluble compound in mitochondria which is able to form a significant portion of adenosine.

Adenine Nucleotides↗
PubMed1989

Mitochondrial metabolism of guanine nucleotides. Possible role of guanosine.

The catabolism of intramitochondrial guanine nucleotides was examined. During 30 min incubation of rat liver mitochondria at 37 degrees C in the presence of oligomycin and carboxyatractyloside, guanine and xanthine were formed and appeared in the medium. Under these conditions, the direct conversion of GMP to guanine by hypoxanthine-guanine phosphoribosyltransferase is suggested to be the main catabolic route within the organelles. Only very small amounts of guanosine were produced and detected both inside and outside the organelles. [14C]Guanosine and [14C]inosine were taken up by the mitochondria. Therefore, guanosine is suggested to be a precursor of intramitochondrial guanine nucleotides.

Animals↗
PubMed1989

Tachyphylaxis with amrinone therapy: association with sequestration and down-regulation of lymphocyte beta-adrenergic receptors.

STUDY OBJECTIVE: To determine whether intravenous therapy with amrinone changes number, location or function of the beta-adrenergic receptors on lymphocytes. DESIGN: Case series. SETTING: Veterans hospital coronary care unit. PATIENTS: Eleven patients with decompensated class III or IV heart failure. INTERVENTIONS: A bolus of intravenous amrinone followed by a continuous infusion at 10 micrograms/kg.min for 72 hours. MEASUREMENTS AND MAIN RESULTS: At 24 to 36 hours there was a reduction in pulmonary capillary wedge pressure (35%), right atrial pressure (20%), and systemic vascular resistance (25%) with an increase in cardiac output (30%). By 72 hours all these parameters had returned nearly to baseline levels. This partial cardiovascular tolerance to amrinone was accompanied by a 126% increase in the plasma epinephrine, a 182% increase in norepinephrine, a 31% decrease in the number of beta-adrenergic receptors on lymphocytes, and a 36% decrease in isoproterenol-stimulated cyclicadenosine monophosphate on lymphocytes. The number of sequestered receptors doubled during the treatment, and the extent of sequestration correlated well with the extent of receptor down-regulation. CONCLUSIONS: The hemodynamic responses to amrinone had virtually returned to baseline by 72 hours. This tolerance was accompanied by increased plasma catecholamines, and a down-regulation, desensitization, and sequestration of beta-adrenergic receptors on lymphocytes. We suggest that these receptor changes also occur in cardiovascular tissues and may in part account for the tolerance to amrinone.

Aged↗