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Biomedical subjects

U Keller

Publications and source records attributed to U Keller.

At least 181 records · Page 10Linked to original sources
PubMed1991

Antihypertensive therapy with Ca2+. Antagonist verapamil and/or ACE inhibitor enalapril in NIDDM patients.

OBJECTIVE: To assess the efficacy and tolerance of a diuretic-free antihypertensive therapy with a Ca2+ antagonist and an angiotensin-converting enzyme (ACE) inhibitor in patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: After a 2-wk washout and a 4-wk placebo phase, 47 hypertensive patients with NIDDM randomly received verapamil or enalapril alone and, if blood pressure remained elevated, both agents combined over 30 wk. RESULTS: Verapamil or enalapril alone normalized blood pressure to less than 90 mmHg diastolic in 30 patients; verapamil decreased mean +/- SE blood pressure from 159/98 +/- 3/1 to 146/87 +/- 3/2 mmHg (n = 18, P less than 0.001) and enalapril from 166/99 +/- 5/2 to 146/86 +/- 3/1 mmHg (n = 12, P less than 0.001). In 17 patients who were still hypertensive after 10 wk of monotherapy, combination of both drugs decreased blood pressure from 170/104 +/- 4/2 to 152/90 +/- 4/2 mmHg (P less than 0.001). Fasting plasma glucose, glycosylated hemoglobin, serum fructosamine, total lipids, high-density and low-density lipoprotein cholesterol, apolipoproteins A-I and B, creatinine, and urinary albumin-creatinine ratio were not significantly modified. CONCLUSIONS: In hypertensive patients with NIDDM, a diuretic-free therapy based on the Ca2+ antagonist verapamil and/or the ACE inhibitor enalapril can effectively decrease blood pressure without adversely affecting carbohydrate and lipid metabolism.

Blood Glucose↗
PubMed1991

[Pulp reactions during Erbium YAG laser irradiation of hard tooth structure].

The Er:YAG Laser is an effective tool for removing hard tooth structure without causing any measurable degree of thermal damage. In view of the fact that the process of ablation basically depends on thermal effects, pulpal microcirculation was studied by Laser-Doppler flowmetry during Er:YAG Laser irradiation. Rat incisors were used to demonstrate that pulp damage can be avoided if correct laser parameters are used for preparing enamel and dentin.

Animals↗
PubMed1991

[Care of edentulous mandible with implant stabilized telescope complete denture].

In comparison to the present junction elements of the implantologic-prosthetic treatment of the toothless lower jaw the dental implant stabilized overdenture is a good alternative. The movable positioning of the resilient telescopes needs the observance of the prosthetic criteria. Having only a guiding function the number of the implants can be reduced to two implants.

Dental Implantation, Endosseous↗
PubMed1990

[The efficacy and tolerance of simvastatin and fenofibrate in primary hypercholesterolemia].

The effects of simvastatin and fenofibrate on blood lipids and the side-effects of these two drugs were compared in a double-blind trial involving 184 adults with primary hypercholesterolemia (total cholesterol levels: 3.87 +/- 1.02 g/l in the simvastatin group, 3.78 +/- 0.79 g/l in the fenofibrate group; N.S.). During a 10-week period, the patients received either fenofibrate 200 mg twice daily or simvastatin 20 mg once daily with doubling of the dosage at week 6 if the LDL-cholesterol level remained above 1.40 g/l. Simvastatin significantly (P less than 0.01) reduced total cholesterol by -29.9 percent, LDL-cholesterol by -35.4 percent, apoprotein B by -27.3 percent and triglycerides by -16.7 percent. Fenofibrate significantly (P less than 0.01) reduced total cholesterol by -19.2 percent, LDL-cholesterol by -22.3 percent apoprotein B by 13.9 percent and triglycerides by 28.9 percent. Reduction of the first 3 parameters was significantly (P less than 0.01) greater with simvastatin and reduction of triglycerides significantly greater with fenofibrate. Apoprotein A1 levels were increased by fenofibrate (+ 7.4 percent) but not by simvastatin. Side-effects occurred with a frequency of 6 percent under simvastatin and 9 percent under fenofibrate.

Adolescent↗
PubMed1990

[Dyslipidemia in diabetes mellitus: significance, diagnosis and treatment].

Dyslipidemias are frequent in diabetic subjects: they increase the risk for atherosclerosis, in addition to the risk of diabetes mellitus per se. The pathogenesis of dyslipidemias differs between type I and type II diabetes: untreated type I diabetic subjects demonstrate frequently increased triglyceride concentrations due to diminished removal of triglyceride-containing particles, as a result of diminished activity of lipoprotein lipase. In addition, more triglycerides are produced due to increased lipolysis and increased free fatty acid supply to the liver. Type II diabetic subjects demonstrate very low density lipoprotein (VLDL) over-production due to obesity, insulin resistance and caloric overconsumption. In addition, triglyceride removal may be diminished due to diminished lipoprotein lipase activity when diabetes mellitus is poorly controlled. In addition, high density lipoprotein (HDL) is frequently lowered. During decompensation low density lipoprotein (LDL) concentrations may also increase. LDL particle composition is frequently abnormal. A severe dyslipidemia in diabetes mellitus is frequently a combined effect of diabetes mellitus and a congenital lipoprotein abnormality. The evaluation and treatment of dyslipidemias in diabetic subjects should be performed similarly to non-diabetics according to the guidelines published recently by the Working Group 'Lipids' of the Swiss Foundation of Cardiology. Additional accents in diabetic subjects are necessary. It is recommended that serum cholesterol, triglycerides and HDL are determined in every patient when diabetes mellitus is diagnosed. If serum cholesterol is greater than 6.5 mmol/l and the cholesterol/HDL-ratio is greater 6.5, dietary treatment should be reinforced; if its effect is insufficient, drug therapy should be considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Arteriosclerosis↗
PubMed1990

[Lipid-lowering therapy in the prevention of coronary heart disease].

Reasons for the current emphasis on cholesterol as coronary risk factor are multiple. On one hand current studies have shown that primary as well as secondary prevention of ischemic heart disease is a realistic possibility with lipid lowering measures. On the other hand new drugs are actually available which permit a potent and adapted therapy of hyperlipidemias. According to new guidelines of the Swiss "lipid task force" screening for hypercholesterolemia is recommended. A cholesterol value greater than 6.5 mmol/l should be investigated and treated. Because a great proportion of adult Swiss fall into this category (approximately 1/3) it is essential that all those are efficiently treated that have markedly abnormal cholesterol values or present with other risk factors such as smoking and hypertension or have a personal or familiar history of ischemic heart disease. Because progression is likely in patients with or after manifest ischemic heart disease even when hypercholesterolemia is mild (over 5.2 mmol/l) all patients presenting with an infarct should be investigated for dyslipidemia. Cholesterol, triglycerides and HDL should be determined. Dietary measures are the basis of every attempt to reduce hyperlipidemia. Most importantly intake of saturated fats prevailing in animal products should be restricted. The next important step is reduction of dietary cholesterol and in obese patients also caloric restriction. Lipid lowering agents are recommended in patients at risk who do not respond to or comply with dietary regimens. According to type of dyslipidemia bile-acid-binding resins, fibrates, nicotinic acid or HMG-CoA reductase inhibitors are available.

Anticholesteremic Agents↗
PubMed1990

[Serum cholesterol of Swiss military personnel and assessment of nutrition in military service].

Two separate studies are reported. The first aimed at assessing the prevalence of hypercholesterolaemia in 453 military personnel who were in service in fall 1988 in a military fort. According to the risk limits of the Swiss Working Group on Lipids, the serum cholesterol values were elevated in 30% (greater than 6.5 mmol/l), in the borderline range in 31% (5.2. to 6.5 mmol/l), and only 39% had values in the ideal range (less than 5.2 mmol/l). There was a significant correlation of serum cholesterol (measured by Reflotron) with age, and the increase between age 20 and 40 was particularly remarkable (1.5 mmol/l increase). There was also a significant correlation of serum cholesterol with body weight. Only 9% of the soldiers knew their cholesterol levels before the study. One third were smokers, and 9% were hypertensive. The second aimed at analysing the consumption of food in the military service. This analysis was performed during a military service in an underground fort, where all food was controlled and known. The analysis indicated that per subject and day, 2051 kcal daily were consumed from the troup kitchen. Additional calories were consumed in the canteen (before and after the main meals) in the form of sweets, particularly as beverages. There were 1053 kcal per person and day consumed in the canteen, consisting of 39% carbohydrates, 36% fat, 15% proteins and 10% alcohol. The study demonstrates on one hand, that a significant number of military personnel demonstrates undesirably high serum cholesterol concentrations; on the other hand, the second study shows that too many calories are consumed during military service and that the foodstuff was too high in fat.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Reversible microangiopathies following massive weight loss].

A 17-year-old patient presented with loss of weight, acrocyanosis and trophic lesions of the tips of the toes. There were no clinical or immunological signs of connective tissue disease. Capillary microscopy revealed a severe organic microangiopathy and arteriolar spasm. A change in the patient's occupational conflict situation was followed by complete recovery and capillary findings normalized. The possible connection between anorexia-like affection and capillariopathy remains unclear.

Adolescent↗
PubMed1990

Biosynthesis of quinoxaline antibiotics: purification and characterization of the quinoxaline-2-carboxylic acid activating enzyme from Streptomyces triostinicus.

A quinoxaline-2-carboxylic acid activating enzyme was purified to homogeneity from triostin-producing Streptomyces triostinicus. It could also be purified from quinomycin-producing Streptomyces echinatus. Triostins and quinomycins are peptide lactones that contain quinoxaline-2-carboxylic acid as chromophoric moiety. The enzyme catalyzes the ATP-pyrophosphate exchange reaction dependent on quinoxaline-2-carboxylic acid and the formation of the corresponding adenylate. Besides quinoxaline-2-carboxylic acid, the enzyme also catalyzes the formation of adenylates from quinoline-2-carboxylic acid and thieno[3,2-b]pyridine-5-carboxylic acid. No adenylates were seen from quinoline-3-carboxylic acid, quinoline-4-carboxylic acid, pyridine-2-carboxylic acid, and 2-pyrazinecarboxylic acid. Previous work [Gauvreau, D., & Waring, M. J. (1984) Can. J. Microbiol. 30, 439-450] revealed that quinoline-2-carboxylic acid and thieno[3,2-b]pyridine-5-carboxylic acid became efficiently incorporated into the corresponding quinoxaline antibiotic analogues in vivo. Together with the data described here, this suggests that the enzyme is part of the quinoxaline antibiotics synthesizing enzyme system. The enzyme displays a native molecular weight of 42,000, whereas in its denatured form it is a polypeptide of Mr 52,000-53,000. It resembles in its behavior actinomycin synthetase I, the chromophore activating enzyme involved in actinomycin biosynthesis [Keller, U., Kleinkauf, H., & Zocher, R. (1984) Biochemistry 23, 1479-1484].

Adenosine Triphosphate↗
PubMed1990

Chromophore activating enzyme involved in the biosynthesis of the mikamycin B antibiotic etamycin from Streptomyces griseoviridus.

A 3-hydroxypicolinic acid activating enzyme from etamycin producing Streptomyces griseoviridus has been purified to apparent homogeneity. Etamycin is a member of mikamycin B antibiotics, chromopeptide lactones, which contain 3-hydroxypicolinic acid (3-HPA) as the chromophoric group. The enzyme catalyzes both the 3-HPA-dependent ATP-pyrophosphate exchange and the formation of 3-HPA adenylate from 3-HPA and ATP. SDS-polyacrylamide gel electrophoresis indicates that the enzyme is a single polypeptide chain with a Mr between 56,000 and 58,000. The molecular mass of the native enzyme was in the same range. In addition to 3-HPA, the enzyme catalyzes the formation of adenylates from picolinic acid, nicotinic acid, and 2-pyrazinecarboxylic acid. Nicotinic acid and picolinic acid when added externally to etamycin producing S. griseoviridus cultures gave rise to the formation of etamycin analogues each containing nicotinic acid or picolinic acid instead of the genuine 3-HPA. The data strongly suggest that the enzyme is involved in the biosynthesis of the chromopeptide lactone etamycin and possibly in that of other mikamycin B antibiotics.

Adenosine Triphosphate↗
PubMed1990

A new method of tooth replantation and autotransplantation: aluminum oxide ceramic for extraoral retrograde root filling.

After an initial clinical test phase, the new method of replantation and transplantation with the use of aluminum oxide ceramic for retrograde root filling may be viewed as possible differential indications to other methods, even to apicectomy in the molar region. Twenty-three of the twenty-five replantations and eight of the nine transplantations may be regarded as having been successful. Contraindications are cases of wide apical foramina and oval or octagonal root canal cross sections.

Aluminum Oxide↗
PubMed1990

Aluminum oxide ceramic pins for retrograde root filling--experiences with a new system.

Retrograde root filling is, under certain conditions, the last chance to keep the functional ability of the teeth. With a new method using aluminum oxide ceramic pins for retrograde root filling, we believe that this aim may be achieved with greater success than with other methods. A success rate of 95% (out of a total of 164 teeth) after 1 year is the result of our investigation. The requirements of retrograde root filling are met in a high degree because of the excellent biologic compatibility of the ceramic material and the high marginal tightness with the use of conical pins.

Adolescent↗
PubMed1990

Delayed disappearance of human compared to porcine insulin in a patient with the insulin autoimmune syndrome.

The insulin autoimmune syndrome is characterised by high titres of autoantibody to insulin, a high circulating concentration of total insulin and later, reactive hypoglycaemia. We have studied a patient with this syndrome whose insulin autoantibody bound exclusively human insulin. This permitted us to investigate the disappearance of bound (human) and unbound (porcine) insulin in the same patient, using i.v. injections of 0.075 U/g of each insulin on separate days. The peak plasma free insulin concentration following porcine insulin was four times greater than that following the same dose of human insulin. The plasma disappearance half-time of porcine insulin following injection was 11 min compared with 32 min following human insulin injection, and the area beneath the disappearance curve of free insulin during the 120 min of sampling was greater for porcine insulin by a factor of 3.15. The nadir in plasma glucose occurred at 45 min following porcine insulin and at 90 min following human insulin injection. The restoration of basal glucose concentration was correspondingly slower following human insulin, but the absolute fall in glucose achieved was no different. There was no evidence of insulin resistance. Insulin autoantibodies can seriously disturb the kinetics and effect of free insulin.

Animals↗
PubMed1990

Systemic pH modifies ketone body production rates and lipolysis in humans.

To investigate whether changes in systemic pH influence ketone body production or utilization, total ketone body (TK) kinetics were measured with [3-14C]acetoacetate and D-beta-[1,3-13C2]hydroxybutyrate tracers in overnight fasted subjects during metabolic alkalosis (NaHCO3 infusion) or acidosis [NH4Cl ingestion or arginine (Arg)-HCl infusion]. Somatostatin, with insulin, glucagon, and growth hormone replacement, was infused in all studies. Blood pH and HCO3- (mM) increased from baseline (0-30 min) to 180-210 min by 0.08 +/- 0.02 and 7 +/- 1 with NaHCO3 and decreased by 0.08 +/- 0.2 and 7 +/- 1 or 5 +/- 1 with NH4Cl or Arg-HCl (all P less than 0.005). Over this period blood TK (microM) differed between the NaHCO3 (+198 +/- 65) and both NH4Cl (-90 +/- 53) and Arg-HCl (-154 +/- 55) (P less than 0.05). These changes resulted from parallel alterations in TK production rate of appearance (Ra TK, mumol.kg-1.min-1), because changes from baseline in Ra 14C TK also differed between NaHCO3 (+1.9 +/- 0.8) and NH4Cl (-1.0 +/- 0.6) and Arg-HCl (-2.0 +/- 0.5) (P less than 0.05). Ra TK calculated with single- or dual-tracer techniques were similar. Blood free fatty acids (FFA) increased with NaHCO3, and FFA and glycerol decreased with NH4Cl and Arg-HCl, suggesting that FFA availability mediated the pH effects on hepatic ketogenesis. These results demonstrate that modest changes in systemic pH modify FFA availability and TK production rates.

Acid-Base Equilibrium↗
PubMed1990

Induction of plasma inhibitors of interleukin 1 and TNF-alpha activity by endotoxin administration to normal humans.

Several naturally occurring inhibitors of interleukin 1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) have been demonstrated both in serum and urine of febrile patients. These factors are considered to be part of a regulatory system counteracting potential deleterious effects of the cytokines. We have assayed plasma samples of volunteers who received a bolus intravenous injection of either 4 ng/kg body wt of Escherichia coli endotoxin (n = 6) or 0.9% saline (n = 4) for the presence of IL-1 and TNF-alpha inhibitory activity. Plasma obtained 3 h after endotoxin injection inhibited IL-1-induced PGE2 release from fibroblasts by 57% (P less than 0.001 vs. baseline and saline controls, respectively). Maximal IL-1 inhibitory capacity coincided with fever and tended to disappear with declining body temperature. Normal plasma was found to inhibit TNF-alpha-induced PGE2 release by 20-35%. This inhibitory effect increased to 50-60% in plasma obtained during endotoxinemia. Maximal TNF-alpha inhibitory capacity became detectable when circulating TNF-alpha levels peaked at 120 min after the injection of endotoxin. Our data demonstrate that both IL-1 and TNF-alpha inhibitory activity can be induced experimentally by intravenous endotoxin administration to humans and that their appearance coincides with fever and circulating TNF-alpha levels.

Adult↗
PubMed1990

[Drugs against obesity].

The position of pharmacotherapy of obesity is still controversial. Different groups of drugs are currently available in Switzerland--none is covered by the health insurances. Apparently the authorities are not convinced of their efficacy. Various groups of drugs have been tried, such as amphetamine derivatives, adrenergic drugs, serotonin agonists or hormones with thermogenic effects, intestinal enzyme inhibitors and dietary fibres. The results of sympathomimetic drugs demonstrate a relatively high incidence of side-effects, and with some preparations there is also the risk of addiction. The serotoninergic drug fenfluramine has been demonstrated in several controlled studies to be an effective weight-reducing agent; however, its effect was relatively modest: It lasted only as long as the drug was taken. Fenfluramine is relatively free of side-effects and is reported to diminish 'carbohydrate craving'.

Amphetamines↗