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Biomedical subjects

E F Pfeiffer

Publications and source records attributed to E F Pfeiffer.

At least 91 records · Page 5Linked to original sources

Tietze's syndrome--a chameleon under the thoracic abdominal pain syndrome.

Tietze's syndrome is characterized by pain due to a self-limiting, localized, non-suppurative swelling of the costochondral or sternoclavicular junction of unknown etiology. The case of a woman is presented here who was submitted to the hospital under the suspicion of a pathological fracture. After extensive investigations the diagnosis of Tietze's syndrome was made by exclusion, and the patient was successfully treated with local injection of an anaesthetic. Possible differential diagnoses of Tietze's syndrome include myocardial infarction, pneumonia, and others. This report emphasizes the importance of a thorough clinical investigation and the need for the exclusion of severe and lifethreatening diseases.

Adult↗

[Pharmacokinetics and pharmacodynamics of protirelin (TRH) in man].

Blood concentrations of thyrotropin-releasing hormone (TRH, Protirelin) were measured by a specific radioimmunoassay in 16 euthyroid subjects after intravenous (200 micrograms), nasal (2 mg) or oral (40 mg) administration of TRH. TRH blood levels peaked 2 min after i.v. administration (13,400 +/- 1,020 fmol/ml), 10 min after nasal (5,000 +/- 1,800 fmol/ml) and 150 min after oral (2,650 +/- 1,080 fmol/ml) administration. The degradation of TRH followed an exponential curve, giving a half-life of 6.5 min. The disappearance rate gave a "half-life" of 22 min in the nasal application group and of 31 min in the oral group. Maximal concentration of stimulated thyrotropin-stimulating hormone (TSH) always occurred 30 min after the peak TRH concentration without any correlation with the TRH concentration time integrals, suggesting that TSH secretion is dependent on a continually rising TRH blood level.

Administration, Intranasal↗

Similar effects of pulsatile and constant intravenous insulin delivery.

Effects of constant and pulsatile i.v. insulin delivery were examined in seven healthy subjects by means of euglycemic clamp technique. Each subject received constant insulin infusion (0.175 mU/kg.min) or insulin pulses at 12-min intervals (2.1 mU/kg) in randomized order for 8-h periods (08.00-16.00 h). Endogenous secretion of insulin was inhibited by concomitant administration of somatostatin (300 micrograms/h). Serum insulin concentrations during constant infusion (12 +/- 1 microU/ml) did not differ from basal values (11 +/- 1 microU/ml). Pulsatile insulin delivery resulted in oscillations of mean concentrations between values of about 10 and 20 microU/ml. Mean blood glucose concentrations during experiments were kept at 80 +/- 1 mg/dl, irrespective of the mode of insulin administration. Moreover, dextrose requirements for maintenance of these glucose concentrations did not differ over the hole periods of examination. We conclude that effects of constant and pulsatile delivery of basal amounts of insulin are not different. This at least applies to peripheral, short-term insulin administration in somatostatin-treated normal man, during an euglycemic clamp.

Adult↗

[Relation between body fat distribution, insulin levels and glucose tolerance in obese females].

Relationship between body fat distribution, serum insulin, and glucose tolerance in obese, non-diabetic women. Recent studies suggest that hyperinsulinemia and upper body obesity are predictive factors for the development of non-insulin-dependent diabetes mellitus. To further characterize the relationship between body fat distribution, serum insulin, and glucose tolerance an oral glucose tolerance test was performed in 48 obese, non-diabetic women. Fasting insulin levels were correlated to both total body fat calculated as body mass index (r = 0.58, p less than 0.001) and upper body fat distribution expressed as waist-to-hip ratio (WHR, r = 0.47, p less than 0.01). In the women with upper body fat localization (WHR greater than 0.90) significantly higher basal and glucose-stimulated insulin concentrations were established than in the women with a lower body type of obesity (WHR less than 0.78) (basal insulin 27.4 +/- 11.5 vs. 15.4 +/- 8.8 mU/l, p less than 0.05, insulin area 779 +/- 320 vs. 468 +/- 237 U, p less than 0.05). They also had impaired glucose tolerance (glucose area 925 +/- 139 vs. 633 +/- 147 U, p less than 0.01). Fasting triglyceride concentrations were correlated both with WHR (r = 0.63, p less than 0.001) and fasting insulin (r = 0.33, p less than 0.05) but not with BMI (r = -0.02, n.s.). A positive association was found between systolic and diastolic blood pressure and both WHR (r = 0.43 and r = 0.44 resp., p less than 0.01) and BMI (each r = 0.35, p less than 0.05). Interestingly, basal insulin was also associated with blood pressure (r = 0.30, p less than 0.1, and r = 0.40, p less than 0.01 resp.).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

Effect of vasoactive intestinal polypeptide (VIP) on glucose and lipid metabolism of isolated rat adipocytes.

The biologic actions of vasoactive intestinal polypeptide (VIP) on insulin binding, glucose uptake and utilization, and on lipolysis were studied. At concentrations between 10(-10) and 10(-7) mol/l VIP influenced neither glucose uptake nor glucose incorporation into lipids under basal and insulin-stimulated conditions. This effect was independent of the presence of adenosine deaminase in the incubation medium. At 10(-8) mol/l VIP increased insulin binding affinity slightly but not significantly, shifting the ID-50 from 12.4 ng/ml to 10.3 ng/ml, without any change in receptor number. However, VIP showed a marked dose-dependent lipolytic activity with the lowest effective concentration at 10(-9) mol/l. At 10(-6) mol/l glycerol release increased 7.3-fold as compared to basal lipolysis. In conclusion, VIP did not affect adipose tissue metabolism at physiologic concentrations. In the rare Verner-Morrison syndrome, however, the potent lipolytic activity of VIP may contribute to the metabolic disturbances observed.

Adipose Tissue↗

Fat distribution, endocrine and metabolic profile in obese women with and without hirsutism.

The relationship between adipose tissue distribution, androgen levels, and metabolic complications of obesity was studied in 20 hirsute and 20 nonhirsute obese premenopausal women. The group of hirsute women showed preferentially an upper body type of obesity as assessed by the waist-to-hip ratio (0.902 + 0.017 v 0.778 +/- 0.015, P less than .01). They had higher serum concentrations of total testosterone (100.4 + 11.7 v 48.8 +/- 4.5 ng/dL, P less than .01) and lower levels of serum sex-hormone-binding globulin (28.1 +/- 3.6 v 44.0 + 4.2 nmol/L, P less than .05) exhibiting an increased androgenic activity as compared to the nonhirsute women. Serum glucose and insulin levels after an oral glucose load were significantly higher in the hirsute women. In addition, the group of hirsute females has significantly higher fasting concentrations of total cholesterol (5.82 +/- 0.28 v 4.75 +/- 0.14 mmol/L, P less than .05) and triglycerides (2.51 +/- 0.38 v 1.14 +/- 0.10 mmol/L, P less than .01). The hirsute group also showed higher systolic (166.7 +/- 5.1 v 142.1 +/- 4.5 mm Hg, P less than .01) and diastolic (100.9 +/- 3.6 v 85.2 +/- 2.5 mm Hg, P less than .01) blood pressure values than the nonhirsute women. Analysis of correlation revealed that an increasing waist-to-hip ratio was accompanied by increasing testosterone levels (r = .39, P less than .05) and by decreasing sex-hormone-binding globulin levels (r = .37, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

Autoantibodies to adrenal medullary and thyroid calcitonin cells in type I diabetes mellitus--a prospective study.

Autoantibodies to adrenal medulla that gave a diffuse immunofluorescent staining pattern were detected in 17 out of 107 (16%) patients with newly diagnosed Type I diabetes mellitus, in 13 out of 178 (7%) patients with long lasting disease but in none of 80 mixed control sera tested. The antibodies were of IgG class and 31 of the 33 positive sera also fixed complement. In 32 out of 34 cases, detection of the antibodies was correlated with the presence in the serum of pancreatic islet cell antibodies (ICA). The specificity of adrenal medullary antibodies is distinct from ICA and from C-cell antibodies since their reactivity was not abolished by preabsorption with extracts from human insulinoma or thyroid C-cell carcinoma. The presence in the serum of antibodies to adrenal medulla is not related to a functional defect of the adrenal medulla, but this new specificity indicates a further autoimmune reaction related to the natural history of Type I diabetes.

Adolescent↗

Endogenous opiates do not influence glucose and lipid metabolism in rat adipocytes.

The effects of the opiates beta-endorphin, dynorphin, met-enkephalin, leu-enkephalin, morphine and of the opiate-antagonist naloxone on glucose metabolism and lipolysis were studied in isolated rat adipocytes. None of the tested substances was found to alter 125I-Insulin binding. The opiates did not influence 2-deoxy-glucose uptake or glucose incorporation into lipids. They also did not exhibit a lipolytic activity. We conclude that the disturbances of glucose homeostasis induced by endogenous opiates are not mediated by an effect on peripheral glucose metabolism.

Adipose Tissue↗

Isolation and partial characterization of insulin of the honeybee (Apis mellifica).

In the honeybee (Apis mellifica), insulin-like material was partially purified with acid ethanol extractions by a classic method for recovering insulin and following gel filtration on a Sephadex G-50 column. The preparations were characterized by their ability to cross-react with porcine insulin antibodies. Insulin-like biological activity was demonstrated using the insulin bioassay. Stimulation of glucose oxidation or lipogenesis was measured by isolated rat adipocytes. Insulin seems to be more widespread in invertebrates than was previously assumed.

Adipose Tissue↗

Seasonal variations of glucose and triiodothyronine concentrations in serum of carp (Cyprinus carpio L).

Thyroid hormone and glucose serum concentrations (SC) of carps (Cyprinus carpio L) have been monitored at weekly intervals throughout the year. T4 and rT3 concentrations were always below the limit of detection of the assays applied. T3 and glucose mean SC showed seasonal variations. Highest T3 SC were reached in summer with a peak value in August and lowest values in winter with a maximum in December. Glucose SC have been found to be highest in winter and lowest in summer. Statistical analysis showed a negative correlation between T3 and serum glucose SC (r = -0.77, P less than 0.001). The seasonal dependency of T3 and glucose SC suggest that either temperature, food intake or day-light or both might play a role in the regulation of glucose metabolism as well as of T3 production or metabolism.

Animals↗

Artificial endocrine pancreas (closed-loop-system for blood sugar control in diabetes mellitus): introduction to the subject.

Clearly, continuous blood glucose monitoring by portable instruments is the only and absolute prerequisite for unprejudiced evaluation of the various strategies for substitution of insulin deficiency in any form of diabetes mellitus. Continuous blood or tissue glucose monitoring remain the prerequisite for reestablishing a satisfactory feedback control mechanism between insulin secretion and blood glucose concentration in any nondiabetic patient. Loss of first-phase insulin secretion produces defects in regulation of carbohydrate metabolism, as in type II diabetic human subjects. All efforts to solve this important problem are justified.

Animals↗

Left ventricular function at rest and during exercise in acute hypothyroidism.

The effect of hypothyroidism on left ventricular function at rest and during exercise was studied in nine patients without demonstrable cardiovascular disease who had had total thyroidectomy and ablative radioiodine treatment for thyroid cancer. Radionuclide ventriculography and simultaneous right heart catheterisation were performed while the patients were hypothyroid two weeks after stopping triiodothyronine treatment (to permit routine screening for metastases) and while they were euthyroid on thyroxine replacement treatment. When the patients were hypothyroid, cardiac output, stroke volume, and end diastolic volume at rest were all lower and peripheral resistance was higher than when they were euthyroid. Pulmonary capillary wedge pressure, right atrial pressure, heart rate, left ventricular ejection fraction, and the systolic pressure:volume relation of the left ventricle, which was used as an estimate of the contractile state, were not significantly different when the patients were hypothyroid or euthyroid. During exercise, heart rate, cardiac output, end diastolic volume, and stroke volume were higher when the patients were euthyroid than when they were hypothyroid. Again, pulmonary capillary wedge pressure, ejection fraction, and the systolic pressure:volume relation were similar in both thyroid states. The data suggest that the alterations in cardiac performance seen in short term hypothyroidism are primarily related to changes in loading conditions and exercise heart rate; they do not suggest that acute thyroid hormone deficiency has a major effect on the contractile properties of the myocardium.

Acute Disease↗

Effects of gastric inhibitory polypeptide on glucose and lipid metabolism of isolated rat adipocytes.

The effects of gastric inhibitory polypeptide (GIP) on glucose and lipid metabolism of isolated rat adipocytes were investigated. In a dose-dependent manner, GIP stimulated 2-deoxy-glucose uptake increasing the glucose transport rate by up to 140% at a concentration of 10(-7) mol/l. GIP also stimulated the conversion of 14C-glucose into extractable lipids by up to 81% at 10(-7) mol/l. Insulin-stimulated 2-deoxy-glucose uptake and lipogenesis were additively enhanced by the presence of GIP. Insulin binding was slightly but not significantly increased by addition of GIP, mainly due to an increase in receptor affinity. GIP had a weak lipolytic activity, but lipolysis elicited by glucagon or isoproterenol was potently reduced. In conclusion, independent of its insulinotropic action, GIP showed a insulin-like activity on glucose metabolism and lipolysis in rat adipose tissue. The possible role of GIP for the development of obesity is discussed.

Adipose Tissue↗

Islet cell antigens. Extraction studies and ELISA analysis.

Whole human and bovine pancreases were extracted in 20 mM Tris-HCl buffer without detergents and fractionated by high-speed centrifugation. The 80,000 x g supernatant was used to coat microtiter plates at a concentration of 5 micrograms protein/ml in phosphate-buffered saline. This solid-phase ELISA system was used for the detection of islet cell antigens defined by a series of monoclonal islet cell antibodies (HISL-1, -4, -5, -8, -14, and -19 and 4F2, 3G5, and A2B5). Both glycoprotein and glycolipid islet cell antigens in the total pancreatic extracts were detected by the monoclonal islet cell antibody in the ELISA system, indicating that epitope preservation had occurred during the extraction procedure. There was a good correlation between islet cell antigen quantitated by the ELISA system and the corresponding islet immunohistochemical reaction. Studies along these lines have the potential to facilitate the design of large-scale protocols for the purification of diabetes-related islet cell antigens to homogeneity.

Animals↗

Substitution of basal delivery of insulin by proinsulin in type I diabetic patients under CSII.

In seven C-peptide negative type I diabetic patients conventional insulin therapy was replaced by CSII using biosynthetic human insulin. After a pretest period of 1-3 days duration, the patients received in randomized order basal subcutaneous infusion of either biosynthetic human proinsulin (assumed potency 4 U/mg) or insulin for two days each. For meals, insulin was given throughout the study. Insulin doses were adjusted to the patients requirements during the prephase. Afterwards changes of basal rates were allowed only in case of nocturnal hypoglycemia; bolus doses were modified when premeal glucose concentrations were outside the range from 80 to 120 mg/dl. During the test period with basal proinsulin infusion, plasma glucose control (MBG, MAGE, M-value) was significantly better (P less than 0.05) when compared to periods with basal insulin infusion. Basal rates of insulin and proinsulin as well as bolus doses of insulin were similar at all study periods. It is concluded that subcutaneous basal proinsulin infusion, supplemented by subcutaneous premeal insulin administration, can be used for glucose control of patients with type I diabetes. As basal proinsulin delivery gives significantly better results than basal insulin delivery, the question arises whether the present formulation of proinsulin is equipotent to insulin formulations.

Adult↗

Differentiation of adipocyte precursor cells from obese and nonobese adult women and from different adipose tissue sites.

We studied adipocyte development in primary cultures of stromal-vascular cells from the adipose tissue of obese and nonobese adult women. Adipose conversion was promoted by addition to confluent cultures of 10(-9) mol/l insulin, 10(-7) mol/l cortisol and for the first two days 0.5 mmol/l 1-methyl-3-isobutylxanthine (MIX). Presence of MIX for a longer period resulted in an increasing differentiation rate. No significant difference in the number of developing fat cells was observed between cultures from 8 obese (body mass index 33.6 +/- 4.1 kg/m2) and from 6 lean (body mass index 22.3 +/- 2.4 kg/m2) adults (390 +/- 102 vs. 354 +/- 85 fat cells/cm2, n.s.). The number of new fat cells obtained in cultures from the subcutaneous fat depot was significantly higher as compared to those obtained in cultures from the intraabdominal fat region (360 +/- 68 vs. 79 +/- 35 fat cells/cm2, p less than 0.01), suggesting the existence of regional variations in the differentiation capacity of adipocyte precursor cells.

Adipose Tissue↗

A potentially implantable enzyme electrode for amperometric measurement of glucose.

A membrane limited amperometric enzyme electrode suitable for glucose measurement in biological fluids was developed. The sensor consists of a central platinum wire (0.3 mm) surrounded by a stainless steel tubing (0.8-1.0 mm outer diameter; 2-4 cm length). By successive dipcoating procedures, layers from cellulose acetate, glucose oxidase (crosslinked with glutaraldehyde) and polyurethane are placed on its surface. The platinum is polarized at +700 mV against steel. In vitro results: Electrodes are stable for at least 6 days. They exhibit a linear range extending to 500 mg/dl glucose. Response times are less than 100 sec. The sensors are not dependent on stirring and are relatively insensitive to changes of pH. Dependency of glucose measurement upon dissolved oxygen is negligible at oxygen concentrations above 0.5 mg/l. In vivo results: Preliminary studies in sheep using subcutaneously implanted needles indicate that short term glucose monitoring is feasible.

Animals↗