Dynamical properties of the self-trapped exciton in AgCl as studied by time-resolved EPR at 95 GHz.
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Journal Article↗
Biomedical subjects
J Schmidt
Publications and source records attributed to J Schmidt.
Control of myogenic factor genes by the membrane depolarization/protein kinase C cascade in chick skeletal muscle.
Myogenic factor genes were found to respond differentially to electrical stimulation of denervated chick skeletal muscle. Myogenin gene activity declined rapidly (t1/2: approximately 2 min), comparable to the rate of acetylcholine receptor (AChR) gene inactivation, while other myogenic bHLH genes either lost activity more slowly (MyoD) or not at all (myf5, herculin). Protein kinase C (PKC) is known to couple membrane activity to AChR gene inactivation; myogenin gene transcription was also rapidly blocked by the PKC activator PMA, whereas electrostimulation remained without effect on myogenin gene activity in muscle that was either exposed to the kinase inhibitor staurosporine or chronically treated with PMA to deplete PKC. These results attest to a special role for myogenin in the activation of AChR genes in denervation supersensitivity.
Alkaloids↗
Rhizobium NodB protein involved in nodulation signal synthesis is a chitooligosaccharide deacetylase.
The common nodulation genes nodABC are conserved in all rhizobia and are involved in synthesis of a lipooligosaccharide signal molecule. This bacterial signal consists of a chitooligosaccharide backbone, which carries at the nonreducing end a fatty acyl chain. The modified chitooligosaccharide molecule triggers development of nodules on the roots of the leguminous host plant. To elucidate the specific role of the NodB protein in nodulation factor synthesis, we have purified recombinant NodB and determined its biochemical role by direct assays. Our data show that the NodB protein of Rhizobium meliloti deacetylates the nonreducing N-acetylglucosamine residue of chitooligosaccharides. The monosaccharide N-acetylglucosamine is not deacetylated by NodB. In the pathway of Nod factor synthesis, deacetylation at the nonreducing end of the oligosaccharide backbone may be a necessary requirement for attachment of the fatty acyl chain.
Acetylglucosamine↗
Long-term results of sutureless phacoemulsification with implantation of a 7-mm polymethyl methacrylate intraocular lens.
In an attempt to minimize postoperative astigmatism while retaining the advantages of implanting intraocular lenses with large optics, sutureless phacoemulsification with implantation of a 7-mm polymethyl methacrylate intraocular lens was performed through a modified scleral tunnel in 100 consecutive patients. Visual and keratometric results, as well as complications, were recorded during a follow-up period of 12 months. Average uncorrected visual acuity improved from 20/153 before surgery to 20/66 as early as 1 week after surgery. Average best corrected visual acuity improved from 20/86 before surgery to 20/39 as early as 1 week after surgery. No significant changes in visual acuity were recorded thereafter. The absolute value of keratometric astigmatism was not increased significantly at any postoperative examination time. The induced cylinder shifted from 1.26 diopters x 74.40 degrees at 1 week to 1.22 D x 1.50 degrees at 1 month after surgery, without further relevant changes thereafter. Mean (+/- SD) endothelial cell loss was 7.2% +/- 6.1% at 1 month and 12.2% +/- 5.4% at 6 months after surgery. Corneal thickness was not increased significantly at any postoperative examination time. Implantation of intraocular lenses with large optics through a scleral tunnel allows quick visual rehabilitation as well as early stability of refraction.
Adult↗
Functional or conventional plate prebending in 90 degrees angled blade plate osteosynthesis of intertrochanteric osteotomies.
The principle of prebending plates is recommended for intertrochanteric osteotomies to reach satisfactory primary stability. This can be done by conventional or functional prebending. Because of the shape of an overbent plate in conventional prebending, when the tension device is used a sliding of the medial wedge of the proximal fragment medially on the distal osteotomy plane takes place. In functional prebending, the final shape of the plate results in almost no movement of the bone fragments. Therefore the measurable interfragmentary compression of functional prebending is better than in the conventional procedure. The functional prebending also causes no loss of primary installed medialisation and there is no need for an additional procedure for the prebending during the operation.
Bone Plates↗
Gut macromolecular permeability in pancreatitis correlates with severity of disease in rats.
BACKGROUND: Increased intestinal macromolecular permeability could allow absorption of substances from the bowel into the systemic circulation and contribute to multiple organ system failure. METHODS: Mild, intermediate, and severe grades of pancreatitis were induced in rats using intravenous caerulein and intraductal glycodeoxycholic acid. [14C]polyethylene glycol (molecular weight, 3350 daltons; 1.1 microCi/142 mg) was instilled into the distal duodenum. At 24 hours, the animals were killed, ascitic fluid was collected for trypsinogen activation peptide measurement, and pancreatic specimens were collected and scored for based on the degree of necrosis, inflammation, and hemorrhage. RESULTS: Gut permeability to polyethylene glycol 3350 (PEG 3350) was increased in animals with early experimental pancreatitis (5.4% +/- 1.2%, n = 20) when compared with control animals (1.8% +/- 0.2%; n = 6) (P = 0.0005). Furthermore, intestinal macromolecular permeability to PEG 3350 correlated with severity of disease as predicted by the method of induction of pancreatitis (P = 0.0003), the histological findings (P = 0.0002), and total ascitic trypsinogen activation peptides content (P = 0.029). CONCLUSIONS: Increased gut permeability in experimental pancreatitis can be correlated with pancreatitis severity.
Animals↗
Hyperoncotic ultrahigh molecular weight dextran solutions reduce trypsinogen activation, prevent acinar necrosis, and lower mortality in rodent pancreatitis.
Acinar necrosis in patients with acute pancreatitis can be due to enzymatic injury, ischemia, or both. We hypothesized that novel therapy aimed at an improvement of pancreatic microcirculation early in the course of pancreatitis may reduce the lethality and acinar damage. Forty-six dextran-resistant rats received controlled intraductal infusion of glycodeoxycholic acid (10 mmol/L), followed by intravenous cerulein (5 micrograms/kg/h) for 6 hours. Beginning 30 minutes after the induction of pancreatitis, all animals were resuscitated with Ringer's lactate (RL) (8 mL/kg/h intravenously for 9 hours). In addition, they were given intra-aortic bolus infusions (2 mL/kg at 30, 60, 90, and 150 minutes) of either RL, sodium chloride (NaCl) (7.5%) and dextran 60,000 (10%) (HHS-60), NaCl (7.5%) and dextran 500,000 (10%) (HHS-500), or NaCl (0.9%) and dextran 500,000 (10%) (DEX-500). Despite high-volume fluid resuscitation in the groups that received RL and HHS-60, 70% of the animals in each of these groups died within 24 hours. In contrast, the mortality rates in the groups of animals that received HHS-500 and DEX-500 were dramatically reduced to 0% and 10%, respectively (p = 0.005, p = 0.02). Histopathologic scores for acinar necrosis were significantly lower in the group of animals that received DEX-500 (p < 0.009) compared with those that received RL and HHS-60. Finally, total amounts of trypsinogen activation peptides in ascites were significantly lower in the animals that received HHS-500 (p < 0.004) and DEX-500 (p < 0.02) compared with those that received RL and HHS-60. Rapid bolus infusion of hyperoncotic ultrahigh molecular weight dextran solution with or without hypertonic saline but not RL or hypertonic-hyperoncotic saline-dextran significantly reduced pathologic trypsinogen activation, prevented acinar necrosis, and improved survival in acute experimental pancreatitis. We speculate that a sustained improvement of pancreatic microcirculation by ultrahigh molecular weight dextran is the mechanism of action.
Animals↗
Saturation by pulse oximetry: comparison of the results obtained by instruments of different brands.
We noticed that arterial oxygen saturation by pulse oximetry (SpO2) was generally lower when determined by the Ohmeda Biox 3700 pulse oximeter than when determined by the Nellcor N-100 pulse oximeter, and we investigated whether this finding was consistent and the reason for the discrepancy. We placed both oximeters simultaneously on 30 infants with indwelling arterial catheters and measured arterial partial pressure of oxygen (PaO2), percentage of fetal hemoglobin, and complete cooximetry, including arterial oxygen saturation (SaO2) with a Radiometer OSM-3 cooximeter, with and without correction for fetal hemoglobin levels, in four samples of blood from each infant during a 12-hour period for a total of 120 samples. The Nellcor SpO2 was consistently higher than the Ohmeda SpO2 by a mean (+/- SD) of 1.61% +/- 2.69% (p < 0.001). The Nellcor SpO2 correlated best with functional SaO2 (oxyhemoglobin (HbO2)/(HbO2 + reduced hemoglobin)) x 100); Ohmeda SpO2 correlated best with fractional SaO2 (HbO2/(HbO2 + reduced hemoglobin + carboxyhemoglobin + methemoglobin)) x 100), reflecting a fundamental difference in the calibration algorithms used in the two instruments. A desired PaO2 of 50 to 100 mm Hg, is maintained when the range of SpO2 is 90% to 96% for Ohmeda SpO2 and 92% to 98% for Nellcor SpO2 in the neonate, giving a positive predictive value in this study of 94% to 95%. We conclude that SpO2 determined by pulse oximeters of different brands is not interchangeable, and this may be of clinical importance in predicting PaO2 on the basis of SpO2.
Catheterization, Peripheral↗
[Internal medicine DES 10 years after creation. Results of the survey realized by the Association of young internists].
The internal medicine young practitioners association (AJI) did set, during 93 spring, a survey among the registered internal medicine interns since 1984, regarding their training and future. 88 did answer, showing a certain homegeneous training but a deep care in their future. Most would wish a dual activity in general hospitals : internal medicine and an other speciality acquired during their training.
Education, Medical↗
[Mechanisms of cardiac involvement in systemic scleroderma, apropos of 3 cases].
We studied myocardial manifestations of systemic sclerosis in three patients. Two patients were symptomatic. A transthoracic echocardiography, a coronary angiography, a cardiac catheterization, thallium scans with dipyridamol completed by thoracic cold exposure and endomyocardial biopsy with immunohistological study were performed. None of them have coronary stenosis. In the three cases abnormalities of myocardial perfusion were detected, two of them have fibrosis. The immunohistological study always showed an anusual expression of HLA DR on cardiac fibroblasts.
Aged↗
Genetic relationship of strains of Haemophilus aphrophilus, H. paraphrophilus, and Actinobacillus actinomycetemcomitans studied by ribotyping.
Strains of H. aphrophilus, H. paraphrophilus, and A. actinomycetemcomitans are phenotypically very similar. Ribotyping of 24 strains of H. aphrophilus, 22 strains of H. paraphrophilus, 8 strains of A. actinomycetemcomitans, and one strain each of the species Pasteurella aerogenes, H. parahaemolyticus, and the genus Capnocytophaga was studied using a non-radioactive digoxigenin labelled probe based on E. coli 16S- and 23S-ribosomal RNA. Restriction fragments were generated using restriction enzyme EcoRI. The ribotypes were analysed by a numerical approach using UPGMA clustering. Two major clusters were seen: One contained all A. actinomycetemcomitans strains, the other all H. aprophilus and all except one H. paraphrophilus strain intermingled between each other. The H. paraphrophilus strain not found in the H. aphrophilus/H. paraphrophilus cluster, the H. parahaemolyticus, P. aerogenes, and the Capnocytophaga strains clustered separately from each other and the two major clusters. The H. paraphrophilus strain with the deviating ribotype was atypical in other respects: it neither did ferment lactose nor mannose and it was isolated from a deer in contradiction to the remaining H. paraphrophilus strains, which were human isolates. This study supports the view that H. aphrophilus and H. paraphrophilus should be regarded as one species separated from A. actinomycetemcomitans.
Aggregatibacter actinomycetemcomitans↗
Phenotypical characters and ribotyping of Pasteurella aerogenes from different sources.
On the occasion of five Danish human Pasteurella aerogenes from pig bite lesions, a comparison was made between 6 isolates from man and 15 animal isolates, mainly from pigs. The strains originated from 6 different countries (USA, Canada, Czechoslovakia, France, Belgium and Denmark). The 21 isolates were characterized by conventional biochemical tests, antibiogram and the API 20 NE kit; finally ribotyping was carried out by hybridizing EcoRI-digested chromosomal DNA with a probe derived from E. coli ribosomal RNA. By ribotyping, 19 of the 21 strains clustered at a similarity level of 81% or more; both phenotypical tests and ribotyping indicated that the remaining two strains did not belong to the species P. aerogenes. In conclusion, despite minor differences our P. aerogenes isolates constituted a well-defined group and they could not be subdivided on basis of animal or geographical origin.
Animals↗
Identity of tumorigenic human urothelial cell lines and 'spontaneously' transformed sublines.
Restriction fragment length polymorphism (RFLP) analysis, comparative marker chromosome analysis, and polymorphic enzyme analysis was carried out on a total of eight human urothelial cell lines and sublines selected according to our knowledge of their HLA-A,B phenotype. RFLP analysis and cytogenetic analysis showed that the cell lines Hu1703He, Hu1922, and T24 are genuine cell lines of different origin. The identity of Hu1703He could not be confirmed by its isozyme phenotype which was identical to the T24 phenotype. RFLP analysis and isozyme analysis revealed that three cell lines, Hu456, Hu549, and Hu961a, and two transformed sublines, HCV-29Tmv and Hu609Tmv, are sublines of T24. A common origin of Hu456, Hu549, Hu961a, HCV-29Tmv, and Hu609Tmv was confirmed by marker chromosome analysis. However, the T24 origin of these cytogenetically related cell lines was not supported by chromosome analysis of T24. RFLP analysis and HLA phenotyping of two tumorigenic and invasive sublines isolated from a culture of non-tumorigenic Hu609 cells showed that non-tumorigenic Hu609 cells can transform 'spontaneously' in vitro into tumorigenic Hu609T cells. The results emphasise the need for careful monitoring and screening of cell lines for their identity using more than one identification parameter.
Cell Line↗
Cytokines and alcoholic liver disease.
It is clear that cytokines cause metabolic disturbances that are similar to known complications of AH. TNF appears to be a proximal mediator of multiple types of experimental liver injury and TNF activity is elevated in ALD, as are the levels of certain other cytokines. On the other hand, low physiologic amounts of cytokines appear to be important for liver regeneration (and perhaps are beneficial to the organism as a whole). Goals for evaluation of anticytokine therapy in ALD will be: (1) determining the timing and type of the particular anticytokine employed (such as, immediate administration of antibody followed by an inhibitor of cytokine production), (2) appropriate monitoring of drug effects on cytokine metabolism as well as liver function and outcome, and (3) maintenance of the regenerative or positive physiologic effects of cytokines while blocking the cytolytic effects. Thus, we predict that ultimate anticytokine therapy will be directed at conserving the positive growth-enhancing effects of cytokines while attenuating their cytolytic effects.
Animals↗
What do medical students mean when they say "sexual harassment"?
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Adult↗
Histological changes of rat lenses after UV-irradiation and D-penicillamine treatment.
The aim of the study was to investigate the effects of local treatment of rat eyes with D-penicillamine (PE) or D-penicillamine disulfide eye drops and their influence on the development of UV-induced lens opacities. 126 Brown Norway rats were divided into 14 groups to test the efficacy of different concentrations of the drugs. During the investigation period, slitlamp examinations and Scheimpflug measurements were performed. The post-mortem analysis comprised biochemical and histological investigations. This paper deals with the histological part of the study. A generally beneficial effect of the substances in question could not be found by means of histological methods. The best effect in relative terms was obtained by the use of 3.0% PE after a pretreatment of 7 days before starting UV irradiation. This result is in agreement with the evaluation of the Scheimpflug photography by microdensitometric image analysis.
Animals↗
[Is internal peritonealization after cesarean section necessary? Results of a randomized study].
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Cesarean Section↗
Exposure to aflatoxin B1 in animal-feed production plant workers.
The exposure to aflatoxin B1 (AFB) in animal-feed processing plants was assessed using binding of AFB to serum albumin. The albumin fraction was digested with pronase, and the digest was purified on a C18 Sepak column and an aflatest affinity column before quantification by ELISA. The level of detectability was 5 pg/mg albumin. The workers served as their own controls, as blood samples were taken upon return from vacation and after 4 weeks of work. A total of 7 of 45 samples were positive for AFB, with an estimated average daily intake of 64 ng AFB/kg body weight. The exposed workers had been disembarking cargos contaminated with AFB or working at places where the dust contained detectable amounts of AFB. The sera from the exposed workers had a significantly higher titer against an aflatoxin B1-epitope than a nonexposed Danish control group. The level of exposure could partly explain the increased risk of liver cancer in workers in the animal-feed processing industry.
Adult↗