[Labor migration in the Gulf region and the impact of the Iraqi invasion of Kuwait].
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Asia↗
Biomedical subjects
G Meyer
Publications and source records attributed to G Meyer.
[Failure-time and risk analysis of fixed partial dentures].
Statistical methods of survival-analysis were applied to investigate the effects of anatomical, constructional and individual factors, which determine the "life-time" of 4371 single crowns, 1669 bridges and 175 fixed splints of a total of 1841 patients of a private insurance company. After 15 years of service 64% of the bridges, 56% of the single crowns and 45% of the splints were still under risk. The number of abutments and units, location, date of insertion, jaw and extension/normal bridge were significant risk factors.
Adult↗
Protein kinase C activation and protooncogene expression in differentiation/retrodifferentiation of human U-937 leukemia cells.
Human U-937 leukemia cells differentiate along the monocytic lineage following 3-day exposures to 12-O-tetradecanoylphorbol-13-acetate (TPA). This induction of differentiation is accompanied by adherence and loss of proliferation, as well as expression/repression of differentiation-associated genes. Long term culture of TPA-differentiated U-937 cells in the absence of phorbol ester for 32-36 days resulted in a process of retrodifferentiation. The retrodifferentiated cells detached from the substrate and reinitiated proliferation. Other cellular parameters, such as glycosidase activities, cytokine release, and filament expression, returned to levels similar to that observed in uninduced cells. Treatment of U-937 cells with TPA resulted in a rapid translocation of protein kinase C (PKC) from the cytosol to cell membrane fractions within 2-8 min. Increased levels of membrane-associated PKC activity persisted until 17-29 days. However, longer periods of incubation were associated with a return to the distribution of PKC in control cells. Activation of PKC has been implicated in the regulation of certain immediate early response genes, and in the present studies, TPA rapidly induced c-fos and c-jun gene expression. Levels of c-fos and c-jun transcripts remained elevated during periods of PKC activation and also returned to levels observed in control cells by 30-36 days, when the cells entered retrodifferentiation. Staurosporine, a nonspecific inhibitor of PKC, partially blocked TPA-induced adherence and growth inhibition and concomitantly prevented TPA-induced c-fos and c-jun gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)
Alkaloids↗
[A long-term study of amalgam and composite fillings].
549 amalgam and 257 composite fillings, which were made by students, were reexamined. The functional loss of restorations was recorded and present fillings were assessed regarding marginal integrity, anatomy, surface condition and colour as referred to composite fillings. After 2-4 years of wear 90.3% of the amalgam fillings were still present, the percentage for 5-8 years-old amalgams was 88.5% and for 9-11 years-old amalgams 85.3%. Composite fillings were substituted or lost at a rate of 7.1% after 2-4 years, 10.8% after 5-8 years and 10.5% after 9-11 years.
Composite Resins↗
[Efficiency of mechanically aided vs. manual root canal irrigation. In vitro comparison].
This in vitro study shows that the cleaning of root canals can be decisively improved in terms of fluid mechanics by using mechanized instruments as opposed to conventional manual irrigation.
Humans↗
[Pathomorphology of wedge-shaped defects].
Our function-oriented SEM studies of various stages of wedge-shaped defects on permanent teeth have shown that wedge-shaped defects probably result from parafunctional force application. These dental hard tissue defects are characterized by marginal surface fractures, arch-shaped enamel tears and axial enamel rod fractures with formation of sagittal gaps. The enamel fractures indicate a dynamic process and do not appear to be the result of improper toothbrushing technique.
Adult↗
[The pig--an experimental model for transplantation of isolated islets pancreatic islets].
The authors present results of autotransplantation of the islets of Langerhans of the pancreas in pigs and miniature pigs ("Troll"). Diabetes was induced by total pancreatomy. From the removed pancreas the islets of Langerhans were separated by the method of intraductal perfusion with collagenase and implanted into the spleen or liver via the portal vein. The mortality on operation in pigs was 33%, in miniature pigs 20%. In domestic pigs normal blood sugar levels were achieved in 25% after implantation of the islets of Langerhans into the liver (in 2 of 8 animals) and in 50% after implantation into the spleen (in 4 of 8 animals). In miniature pigs autotransplantation of the islets of Langerhans was equally successful when transplanted into the liver or the spleen -50%. The 50% success of autotransplantations justifies the use of pigs as a model for further investigations of allo- or xenotransplantations of the islets of Langerhans.
Animals↗
[Classification of gamblers from self-help groups using cluster analysis].
In an empirically based classification by cluster analysis of 437 gamblers from self-help groups five distinct homogeneous subgroups were determined on the basis of such characteristics as frequency of gambling of various kinds, function of gambling and sensation during gambling, symptoms of pathological gambling as well as personality characteristics. These can be characterized as: Pathological slot-machine gamblers with 1) an emotionally instable, depressive-aggressive personality structure and 2) an emotionally instable, depressive personality structure; 3) pathological gamblers on German-style slot-machines and 4) pathological gamblers on classical games of chance--both without conspicuous personality, and 5) gamblers on German-style slot-machines under a subjective strain. On the whole, the distinctions are due to psychological variables, the social data hardly differ. A comparison of the subgroups on the basis of variables regarding the course and result of treatment shows that the pathological gamblers with a conspicuous personality structure more often failed to reach, the goal of abstinence set by "Gamblers Anonymous" and instead report about an improvement of their gambling behaviour. On the other hand, the gamblers on German-style slot-machines who were under a subjective strain more often found it easier to stop gambling completely. The results of the cluster analysis are compared with clinical diagnostic classifications of gamblers who received out-patient or in-patient treatment as well as with empirical classifications of addicts, and first hypotheses of a differential therapy indication are being discussed.
Adolescent↗
Substance P- and opioid-immunoreactive structures in olfactory centers of the cat: adult pattern and postnatal development.
Substance P (SP)-ir and opioid-ir structures were studied in the cat main olfactory bulb (MOB), accessory olfactory bulb (AOB), and olfactory peduncle. In the MOB, the opioid-ir and the majority of the SP-ir neurons belong to the granule cell type. SP-ir granule cells reside in the deeper granule cell layer, whereas opioid-ir granule cells reside in the superficial granule cell layer, internal plexiform, and mitral cell layer. Many granule cells are observed in the external plexiform and glomerular layer. Other granule cells were found in the bulbar/peduncular white matter, the taenia tecta, and the genu of the corpus callosum. A new substance P-ir cell type was identified in the glomerular layer. This cell type was also identified by using the technique of intracellular injection of Lucifer Yellow. The cell type corresponds neither to the external tufted type nor to the short axon cell types described so far. The AOB resembles the MOB with respect to large numbers of SP-ir and opioid-ir granule cells. In addition, a few opioid-ir neurons, probably superficial mitral cells, were found in the glomerular layer. The AOB is surrounded by islands of immunoreactive granule cells, which connect to the granule cell layer by extremely long processes. Opioid-ir and SP-ir beaded axons pass through the olfactory peduncle terminating on granule cells, and ascend as far as the glomerular layer. All subdivisions of the anterior olfactory nucleus (AON) contain immunoreactive terminal fields. Afferent fibers and terminal plexuses derive from a population of immunoreactive neurons located predominantly in the region of the septo-olfactory junction. They have large somata. Their axons form recurrent collaterals, some of which run rostrally in the peduncular white matter. Others ascend caudally towards the septal region. The fibers seem to remain ipsilaterally, since the olfactory limb of the anterior commissure and the commissure proper are devoid of SP-ir and opioid-ir fibers. During development SP and opioid immunoreactivity were found only in differentiated granule cells. The peptides were not detectable in migrating or immature granule cells, as identified in Golgi-impregnated material. The granule cell population largely develops during postnatal life. The number of opioid-ir granule cells increases slowly and continuously, reaching the adult level not before the sixth postnatal month. Strikingly, SP-ir granule cell number increases fast and reaches a transient peak during the second month. Thereafter it declines (40% decrease) to the adult density, which is similar to that of opioid-ir granule cells.
Afferent Pathways↗
Evidence for trimer reconstruction of Si(111) sqrt 3 x sqrt 3 -Sb: Scanning tunneling microscopy and first-principles theory.
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Journal Article↗
[Interruption of the inferior vena cava in thromboembolic pathology].
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Anticoagulants↗
[In vitro and in vivo studies of isolation, transplantation and function of Langerhans islets in the swine].
Limits and possibilities of the transplantation of islets of Langerhans in pigs were studied. 6 x 10(4) to 3 x 10(6) islets and insulin producing fragments per pancreas were obtained by intraductal collagenase digestion of the pancreatic gland following total pancreatectomy. Islets grafted into the spleen or liver rendered normoglycemia to the pancreatectomized animals as demonstrated by normal fasting blood sugars and normal intravenous glucose tolerance tests as compared to not operated animals permitting a survival time of up to one year. Apancreatic controls died of ketoacidosis and diabetic coma 10 to 12 days posttransplant. The number of isolated and transplanted islets correlated well to the normoglycemic state of the animal. Beyond that the in vitro challenge of the islets with glucose and resulting insulin secretion was a very important indicator for the functional status and integrity of the islets after transplantation. Thus the pig appears to be a suitable model for the preclinical studying of islet transplantation especially since immunologic, physiologic and anatomic features of the pig are similar to those in the human regarding pancreas and nutrition.
Animals↗
Direct screening of a small genome: estimation of the magnitude of plant gene expression changes during adaptation to high salt.
Mesembryanthemum crystallinum (common ice plant), a facultative halophyte with a genome size of 393,000 kb, was used to estimate the magnitude of changes in gene expression in response to environmental stress by excess salt. Such treatment induces a water-conserving pathway of carbon assimilation (CAM) which is, at least in part, transcriptionally controlled. From a genomic library, 200 phage containing approximately 3200 kb (0.8% of the genome) were randomly selected. The inserts in these clones could be divided into four classes ranging from highly repetitive DNA (class I clones) to single-copy DNA (class IV clones). The inserts of the 166 clones of classes II to IV were digested with various restriction enzymes and the fragments were analyzed by hybridization with radioactively labelled mRNA isolated from stressed and unstressed leaves. We found that a total of approximately 140 DNA fragments hybridized with the RNA probe. Among those, several differentially regulated transcripts were observed. Stress-dependent fluctuation of mRNA abundance was verified by Northern analyses: one mRNA, not detectable in unstressed leaves, appeared in stressed leaves, while steady-state levels of three transcripts decreased during stress. All regulated signals are derived from low abundance mRNAs, which may be missed during screening of cDNA libraries. We conclude from these results that, for the entire genome, on the order of more than one hundred genes are differentially regulated in response to salt stress.
Blotting, Southern↗
Fistuloscopy--an adjuvant technique for sealing gastrointestinal fistulae.
Endoscopic occlusion of gastrointestinal fistulae can be successfully achieved in a high percentage of patients. In cases where the intestinal opening of the fistula is not accessible, such treatment was hitherto impracticable. Fistuloscopy is a new technique which we have devised, using a flexible endoscope advanced percutaneously along the fistula tract to seal these gastrointestinal fistulae. Eleven out of 17 enterocutaneous fistulae and 5 out of 8 abscesses could be sealed using this technique. The complications in this series were all caused by fibrin glue injection into the fistulae under pressure. One patient died of an air embolism. Provided that elevation of the air pressure in the fistula system is strictly avoided, fistuloscopy is a safe and potent method of occluding gastrointestinal fistulae, which otherwise need prolonged conservative treatment or hazardous surgical intervention.
Aged↗
Comparison of perfusion lung scanning and angiography in the estimation of vascular obstruction in acute pulmonary embolism.
To determine the relationships between perfusion scan defect and angiographic severity (Miller index) in acute pulmonary embolism, we analysed examinations obtained before and after thrombolytic therapy in 34 consecutive patients free from underlying cardiopulmonary disease. The overall agreement between the two techniques was excellent (r = 0.82; mean absolute difference = 2.8%), although when embolic involvement was extensive (greater than 50% angiographic obstruction), the perfusion scan moderately underestimated (4%) the defect seen angiographically. These findings suggest that the pulmonary lung scan is a reliable method of assessing the initial pulmonary vascular obstruction as well as of quantifying any changes induced by or associated with the treatment.
Angiography↗
The nature of the neutral Na(+)-Cl- coupled entry at the apical membrane of rabbit gallbladder epithelium: III. Analysis of transports on membrane vesicles.
In rabbit gallbladder epithelium, a Na+/H+, Cl-/HCO3- double exchange and a Na(+)-Cl- symport are both present, but experiments on intact tissue cannot resolve whether the two transport systems operate simultaneously. Thus, isolated apical plasma membrane vesicles were prepared. After preloading with Na+, injection into a sodium-free medium caused a stable intravesicular acidification (monitored with the acridine orange fluorescence quenching method) that was reversed by Na+ addition to the external solution. Although to a lesser extent, acidification took place also in experiments with an electric potential difference (PD) equal to 0. If a preset pH difference (delta pH) was imposed [( H+]in greater than [H+]out, PD = 0), the addition of Na-gluconate to the external solution caused delta pH dissipation at a rate that followed saturation kinetics. Amiloride (10(-4) M) reduced the delta pH dissipation rate. Taken together, these data indicate the presence of Na+ and H+ conductances in addition to an amiloride-sensitive, electroneutral Na+/H+ exchange. An inwardly directed [Cl-] gradient (PD = 0) did not induce intravesicular acidification. Therefore, in this preparation, there was no evidence for the presence of a Cl-/OH- exchange. When both [Na+] and [Cl-] gradients (outwardly directed, PD = 0) were present, fluorescence quenching reached a maximum 20-30 sec after vesicle injection and then quickly decreased. The decrease was not observed in the presence of a [Na+] gradient alone or the same [Na+] gradient with Cl- at equal concentrations at both sides. Similarly, the decrease was abolished in the presence of both Na+ and Cl- concentration gradients and hydrochlorothiazide (5 x 10(-4) M). The decrease was not influenced by an inhibitor of Cl-/OH- exchange (10(-4) M furosemide) or of Na(+)-K(+)-2Cl- symport (10(-5) M bumetanide). We conclude that a Na+/H+ exchange and a Na(+)-Cl- symport are present and act simultaneously. This suggests that in intact tissue the Na(+)-Cl- symport is also likely to work in parallel with the Na+/H+ exchange and does not represent an induced homeostatic reaction of the epithelium when Na+/H+ exchange is inhibited.
Amiloride↗
31P NMR spectroscopy for in vitro viability testing of porcine pancreatic islets.
The quality of pancreatic islets prepared by an intraductal pancreas collagenase perfusion technique was tested using three independent methods: 31P NMR spectroscopy, an insulin secretion test, and a staining method. The viability of pancreatic islet tissue was evaluated using the ratio of phosphate diester to phosphate monoester (PDE/PME) as a new criterion obtained by 31P NMR spectroscopy. According to this criterion, three types of tissue fragments could be characterized: vital (PDE/PME 0.5-0.9), damaged (PDE/PME less than 0.2), and necrotic (no PDE, no PME). The findings in the three different groups could be correlated to three trends of insulin secretion of the preparations following glucose challenge: good response to the glucose challenge, continuous decrease of insulin production, and no insulin secretion. We feel that 31P NMR spectroscopy offers a rapid and suitable method for classifying the viability of isolated pancreatic islets.
Animals↗
[Late para-aortic recurrence of dysgerminoma].
Most of the recurrences in patients with dysgerminoma occur, in more than 80%, in the first 2 years. Late recurrences are very rare. In this paper we report on a paraaortic recurrence, 12 years after primary therapy. Tumour biology and its influence on indication for surgery are discussed. Therapy of recurrence should be individualized including surgery, chemotherapy and radiotherapy. High remission rates in patients with recurrent dysgerminoma can be expected. In fact, our patient has been tumour-free for more than 5 years.
Adult↗