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Biomedical subjects

E Schmidt

Publications and source records attributed to E Schmidt.

At least 163 records · Page 9Linked to original sources
PubMed1992

Lipoprotein (a): a risk factor for retinal vascular occlusion.

The protein moiety of lipoprotein (a) consists of apoB-100 and apolipoprotein (a). Lipoprotein (a) is an independent risk factor for premature atherosclerosis. Apolipoprotein (a) and plasminogen are structurally homologous. Through interference with the fibrinolytic system, lipoprotein (a) may act as a thrombogenic factor. In the present study, we determined lipoprotein (a) concentrations in 84 patients (60 men and 24 women) with retinal vascular occlusion (RVO) and in 2 groups of healthy volunteers (n = 40 and 46). In all, 29% of the patients had Lp (a) levels of above 300 mg/l. In the two reference groups, only 10% and 9% of the subjects exceeded this level. According to the chi-square test, the association between Lp (a) levels and RVO was significant. Lp (a) concentrations did not differ between patients with arterial occlusion and those with venous occlusion. No difference in the total cholesterol, triglyceride, or LDL-cholesterol values was observed between patients and controls. We therefore conclude that Lp (a) represents an independent risk factor for RVO.

Adolescent↗
PubMed1991

In vivo studies on alpha-adrenergic receptor subtypes in human veins.

We studied in vivo responsiveness of venous alpha 1- and alpha 2-adrenoceptors, measuring the diameter changes in superficial veins in response to alpha-adrenergic agonists and antagonists in healthy human volunteers. The dorsal hand vein technique was used because it permits complete dose-response studies of venous constriction without confounding reflex alterations. Local infusions of all agonists studied induced dose-dependent contraction of the hand vein; the maximal effects (Emax) were: norepinephrine (88% +/- 10%), methoxamine (97% +/- 5%), phenylephrine (95% +/- 6%), clonidine 54% +/- 12%), and azepexole (68% +/- 26%). Clonidine reduced the norepinephrine-induced venoconstriction by 11% +/- 10%. Oral doses of 1 mg prazosin antagonized the venoconstriction induced by norepinephrine, methoxamine, and clonidine, but not by azepexole. Yohimbine-antagonism was observed against all agonists studied. Inhibition by yohimbine of clonidine-induced venoconstriction was irreversible over 60-180 min. Results show that the in vivo effects on veins of alpha-adrenergic agonists are in good agreement with results from in vitro experiments. Agonists with alpha 1- and alpha 2-adrenoceptor subtype selectivity cause venoconstriction in vivo, but alpha 2-receptor mediated constriction is intrinsically weaker. Clonidine acts as a partial antagonist against norepinephrine, presumably on postsynaptic alpha 2-receptors. At high doses, alpha 2-adrenoceptor subtype selectivity of clonidine and yohimbine appear to be partially lost in vivo.

Adrenergic alpha-Agonists↗
PubMed1991

Effect on smoking cessation of silver acetate, nicotine and ordinary chewing gum. Influence of smoking history.

In a randomized smoking cessation study 211, 203 and 82 persons were supported with nicotine, silver acetate and ordinary chewing gum, respectively. After 26 weeks there was no overall difference in number of abstainers between treatments. Participants were divided into subsets with low and high weighted packyears consumption (WPY) which modifies tobacco consumption by nicotine content. Abstainer rates in the total population controlled for treatment decreased with increasing WPY (P less than 0.005). In participants with low WPY abstainer rate was higher in the silver acetate group compared to the nicotine (P less than 0.0005) and ordinary (P less than 0.05) chewing gum groups. Nicotine chewing gum was more effective than silver acetate (P less than 0.05) and ordinary (P less than 0.05) chewing gum in smokers with high WPY. Ratings on some inconveniences experienced during earlier attempts to quit smoking influenced the ability to break the habit but had no influence on chewing gum effects. This study indicated that through consideration of smoking history it should be possible to individualize pharmacological support to smokers wanting to quit, with silver acetate chewing gum most effective for smokers with a low WPY and nicotine chewing gum most effective for smokers with a high WPY.

Acetates↗
PubMed1991

Fibrosis of the liver in rats induced by bile duct ligation. Effects of inhibition by prolyl 4-hydroxylase.

The model of biliary cirrhosis by bile duct ligation was further characterized using PIIIP, 7S-collagen as well as standard enzymes in the serum, prolyl 4-hydroxylase and total hydroxyproline in the liver and light microscopical histology. Five weeks after bile duct ligation there was an increase in total collagen content of the liver to 510% of initial values accompanied by an increase of serum-PIIIP (225%) and 7S-collagen (389%). The time-course of this connective tissue proliferation was biphasic with an initial phase of cholestasis and cellular damage followed by rapidly increasing collagen accumulation. The novel prolyl 4-hydroxylase inhibitor HOE 077 reduced the accumulation of collagen in the liver over 6 weeks by 48%. There were no apparent side effects and treated animals showed a tendency towards less functional impairment. The drug's effects, however, were not dose-dependent between daily doses of two times 2 mg/kg and two times 10 mg/kg. These results emphasize the usefulness of the bile duct ligation model for studies of collagen metabolism. They show HOE 077 to be a promising agent for the inhibition of hepatic fibrosis.

Animals↗
PubMed1991

Energy expenditure and substrate metabolism in ethanol-induced liver cirrhosis.

Energy expenditure and substrate metabolism were investigated in 10 patients with alcoholic liver cirrhosis (EtOH-Ci) and 10 healthy controls (C). Resting metabolic rate (RMR) varied from 1,269 to 2,467 kcal/day in C and from 1,228 to 2,098 kcal/day in EtOH-Ci. RMR was significantly related to fat-free mass (FFM) in both groups, but EtOH-Ci decreased FFM and increased RMR when expressed per kilogram FFM (+33%). Glucose intolerance, hyperinsulinemia, and a decreased C-peptide-to-insulin ratio were observed in EtOH-Ci after a test meal. Concomitantly, nonoxidative glucose metabolism was reduced in association with normal increases in glucose oxidation. EtOH-Ci reduced insulin sensitivity (-59%) and maximal insulin-dependent glucose disposal (-40%) during a sequential two-step glucose clamp protocol (phase 1: 1 mU.kg body wt-1.min-1 insulin infusion rate + euglycemia; phase 2: 4 mU.kg body wt-1.min-1 insulin infusion rate + 165 mg/dl plasma glucose concentration). This was explained by reduced glucose storage (-99%, -51%) in association with normal responses in glucose oxidation rate, plasma lactate concentration, lipid oxidation rate, and rate of lipogenesis. Defective glucose storage was independent of reduced FFM. EtOH-Ci increased glucose-induced thermogenesis by 57%. We conclude that increased resting metabolic rate, enhanced thermogenesis, defective glucose storage, and normal glucose oxidation together result in increased energy needs and favor negative energy balance in patients with alcoholic cirrhosis.

Adult↗
PubMed1991

Effects of metronidazole on periodontal treatment needs.

Periodontitis, a common cause of tooth loss in adult populations, is an inflammatory response to the overgrowth of anaerobic organisms such as spirochetes and bacteroides and, in some cases, micro-aerophilic organisms in the subgingival plaque. In the present investigation, using a double-blind clinical design, we sought to determine whether 1 week of metronidazole treatment plus debridement of the tooth surfaces was superior to 1 week of placebo treatment plus debridement (positive control) in reducing the subsequent amount of periodontal surgery given to the patients. Thirty-nine patients were randomly assigned to either the metronidazole or placebo (positive control) groups. All patients were given the necessary scaling and root planing and were unsupervised in their usage of the medication. After the completion of this treatment, they were reexamined and it was found that the metronidazole regimen caused a significant reduction in surgical needs of about 5 teeth per patient compared to the positive control (difference before and after treatment 8.3 +/- 6.8 teeth metronidazole versus 2.9 +/- 4.8 positive control, P = 0.007). The difference between groups was maintained during the 2 to 3 years' recall period. Metronidazole had a significant effect on the site specific reduction of spirochetes: 90% of the sites in the metronidazole group versus 64% in the positive-control group had a decrease in the percentage of spirochetes (P less than 0.05). We conclude that systemic metronidazole given 250 mg tid for 7 days in conjunction with debridement of the tooth surfaces can significantly reduce the need for periodontal surgery compared to the standard regimen which included only debridement.

Alveolar Bone Loss↗
PubMed1991

The effect of nicotine, silver acetate, and placebo chewing gum on the cessation of smoking. The influence of smoking type and nicotine dependence.

The effects of nicotine (NI), silver acetate (SA), and ordinary (PL) chewing gum on the cessation of smoking were compared through ratings on six smoking types and physiological nicotine dependence (F-score) in a placebo-controlled and randomized study that included 496 smokers in a group-support setting. Results were evaluated after 26 weeks. Ratings on smoking types 1, 3, 4, 5, and 6 and F-score were related to success rates. The effect of NI was superior to SA in smokers with high type 1 ratings, the effects of NI and SA were almost equal and superior to PL in smokers with high type 4 and 6 ratings, and the effect was independent of the F-score. Treatment of smokers with NI and SA should be restricted to smoking types in which an effect superior to PL is documented, and research should be performed to find support for smoking types where SA and NI have a clear effect.

Acetates↗
PubMed1991

[Not Available].

Explore the source record for details and available documents.

Germany↗
PubMed1991

SV40 T antigen transforms calcitonin cells of the thyroid but not CGRP-containing neurons in transgenic mice.

Neurons are postmitotic for the adult life of animals. Tumors rarely, if ever, arise from neurons in the adult, although they do from other cells from the same lineage, such as the neuroendocrine C cells of the thyroid. We have found that 2 kb of the calcitonin gene-related peptide (CGRP)/calcitonin gene suffices to target expression to CGRP-containing neurons, such as those in the dorsal root ganglia (DRG), and to the calcitonin-secreting C cells of the thyroid. Using this promoter we have examined the effect of two potentially transforming oncogenes in these two different populations. Overexpression of c-myc for periods of up to two years does not transform either cell type, whereas SV40 Tag causes early onset medullary thyroid carcinoma, but does not transform the dorsal root ganglia neurons. This suggests that as part of the terminal differentiation process of these neurons, the cessation of mitosis is accompanied by a relative refractoriness to oncogenes that may transform other cells of the same lineage.

Animals↗
PubMed1991

[Psychosomatic medicine as joyful or questionable science].

Psychosomatic medicine tries to join different epistemological and ontological principles and views and contributes this way to a theoretical confusion. Emergentist phenomenon as a limiting concept should show the bound between the different outlines and avoid rough confusions. Systemic theory allows the relating distribution of the under different ways observated phenomena.

Humans↗
PubMed1991

[Surgical indications and procedure in Crohn disease and ulcerative colitis].

Inspite of a higher prevalence of ulcerative colitis complications of Crohn's disease make a surgical intervention more often necessary. Emergent operations of ulcerative colitis confront with minimal surgery of Crohn's disease. Today the basic treatment of both diseases is conservative; an elective operation at the right moment may reduce on the other hand the number of emergency cases.

Colectomy↗
PubMed1990

Degradation of 3-chlorobiphenyl by in vivo constructed hybrid pseudomonads.

3-Chlorobiphenyl-degrading bacteria were obtained from the mating between Pseudomonas putida strain BN10 and Pseudomonas sp. strain B13. Strains such as BN210 resulted from the transfer of the genes coding the enzyme sequence for the degradation of chlorocatechols from B13 into BN10, whereas B13 derivatives such as B131 have acquired the biphenyl degradation sequence from BN10. During growth of the hybrid strains on 3-chlorobiphenyl 90% chloride was released. Activities of phenylcatechol 2,3-dioxygenase, benzoate dioxygenase, catechol 1,2-dioxygenase, chloromuconate cyloisomerase and 4-carboxymethylenebut-2-en-4-olide hydrolase were found in 3-chlorobiphenyl-grown cells. The hybrid strains were found to convert some congeners of the Aroclor 1221 mixture such as mono- and dichloro-substituted biphenyls.

Aroclors↗
PubMed1990

Significance of the in vivo deuterated phenylalanine load for long-term phenylalanine tolerance and psycho-intellectual outcome in patients with PKU.

In 20 patients with PAH deficiency, in vivo RA was determined by an intravenous deuterated Phe load. Sixteen patients had RAs of less than 0.4% of normal, 3 a clearly detectable activity between 0.8 and 1.4% of normal. Long-term Phe tolerance as measured by the distribution of plasma Phe levels in categories (0-3.9, 4.0-9.9, 10-15.9 and over 16 mg/dl) was much improved in patients with RAs greater than 0.8%. There was a negative correlation between RA and number of plasma Phe levels greater than 16 mg/dl. Relationship between full scale IQ at the age of 9 years and dietary control showed a positive correlation between IQ and the number of Phe levels between 0-10 mg/dl (k = .50 p less than 0.05). Highest (negative) correlation (k = -0.67 p less than 0.007) was found between full scale IQ and the number of Phe values greater than 16 mg/dl as measured over 9 years. On the one hand detectable RA of PAH reduces the risk of high Phe levels and thus may also reduce the risk of brain damage in untreated or suboptimally treated patients with PAH. On the other hand enzyme measurement of PAH is no predictive parameter for Phe tolerance in an individual patient since RA may be very similar in phenylketonuric/hyperphenylalaninaemic patients. For practical purposes the oral protein loading test at the age of 6 months will give the most reliable results for differential diagnosis of PAH deficiency.

Aging↗
PubMed1990

Results of psychological testing of patients aged 3-6 years.

Cognitive development of early treated PKU children (132) was investigated by intelligence tests, tests for visual perception, motor and language development. Deviations from test norms occurred at 5 years of age concerning performance IQ, mathematical thinking, and visual perception. With the exception of mathematical thinking, "normal" results were obtained at the age of 6 years. Correlation with levels of plasma Phe revealed a relation between quality of dietary control and performance IQ. Results are discussed in light of methodological aspects and with respect to treatment consequence.

Child, Preschool↗