Bericht über das Internationale Symposium «Nerve Fibres and Inflammation», Erlangen, 13.–16. März 1988

Ohne Zusammenfassung     

The thyroid axis and desipramine treatment in depression

Although there has been much recent investigation of the role of thyroid function in affective illness, few studies have addressed the effects of the tricyclic antidepressants on the pituitary-thyroid axis. In the present study, thyroid functions (TFTs) and thyrotropin-releasing hormone (TRH) stimulation of thyroid-stimulating hormone (TSH) were measured before and after treatment with desipramine (DMI) in 13 men with a diagnosis of major depressive disorder. All subjects had normal TFTs and baseline TSH measured in a drug-free state at the initiation of the study. Both mean free thyroxine index and baseline TSH decreased after DMI treatment. The amount of decrease in baseline TSH correlated with increase in delta TSH. Four subjects had blunted delta TSH (delta TSH less than or equal to 5 microIU/ml); three of these subjects "normalized" with treatment (delta TSH less than or equal to 5 microIU/ml; greater than or equal to 20 microIU/ml). Two subjects had a high delta TSH, and both "normalized" during treatment. The decrease in both free T4 index and TSH suggests a down-regulation of the thyroid axis at the hypothalamic level. "Normalization" of subtle dysregulation of the thyroid axis is suggested as a mechanism of antidepressant therapy in the treatment of some depressions.     

Radiologic search for embolized leaflets of prosthetic heart valves: A report of two cases

In a radiologic search for embolized leaflets of Edwards-Duromedics bileaflet valves in 2 patients, the embolized fragments were localized in the iliac vessels using computed tomography. Sonography was successful in one case and standard X-ray films of the abdomen were negative in both cases.In vitro investigations with Björk-Shiley and Edwards-Duromedics leaflets suggested that standard X-ray films of the abdomen and pelvis should be considered as the first investigational technique. If negative, computed tomography of the lower abdomen should be done.     

Effect of a new synthetic serum replacement on insulin and somatostatin secretion from isolated rat pancreatic islets in long-term culture

Summary Serum contains insulin degrading components. We have evaluated the insulin and somatostatin secretion from isolated rat pancreatic islets during a 2-wk culture period using three different serum-containing media, and one serum-free medium with a synthetic serum replacement. Islets incubated in serum-free medium elicited significantly higher daily insulin and somatostatin secretions than islets incubated in the serum-containing media. After a 2-wk culture period, islets from the serum-free medium secreted significantly more insulin and somatostatin than islets cultured in other media when stimulated with 25 mmol/liter glucose together with 15 mmol/liter theophylline. We conclude that the serum-free medium is superior for long-term culture of rat pancreatic islets.     

Züchtung des Variolavirus in der infantilen Maus

Zusammenfassung Das Variolavirus konnte aus menschlichem Pustel- und Krustenmaterial intraperitoneal in infantilen Mäusen angezüchtet und in fortlaufenden Passagen weitergeführt werden. Es blieb innerhalb von 20 Passagen in bezug auf seine biologischen Eigenschaften im Hühnerembryo stabil. Eintägige Mäuse waren empfänglicher als dreitägige Tiere. Innerhalb verschiedener Mäusefamilien bestand eine unterschiedliche Resistenz gegenüber der Variolainfektion. Bei resistenteren Tieren vermehrte sich das Virus, ohne klinische Erscheinungen zu verursachen.Ein besonders bevorzugtes Organ für die Vermehrung des Variolavirus war die Lunge.Bei infizierten, klinisch aber gesunden Mäusen ließ sich aus den Lungen der Tiere in einem Zeitraum von 45 Tagen p. i. infektiöses Variolavirus züchten.     

Mental and physical effort affect vigilance differently.

Both physical and mental effort are thought to affect vigilance. Mental effort is known for its vigilance declining effects, but the effects of physical effort are less clear. This study investigated whether these two forms of effort affect the EEG and subjective alertness differently. Participants performed a physical task and were subsequently presented with a mental task, or vice versa. Mental effort decreased subjective alertness and increased theta power in the EEG. Both results suggest a vigilance decline. Physical effort, however, increased subjective alertness and alpha and beta1 power in the EEG. These findings point towards an increase in vigilance. Beta2 power was reduced after physical effort, which may reflect a decrease in active cognitive processing. No transfer effects were found between the effort conditions, suggesting that the effects of mental and physical effort are distinct. It is concluded that mental effort decreases vigilance, whereas physical effort increases vigilance without improving subsequent task performance.     

Detection of Leishmania infantum kinetoplast DNA in laryngeal tissue from an immunocompetent patient

Mucosal leishmaniasis of the upper respiratory tract is usually associated with the visceral form or is found in immunosuppressed individuals. This report presents a case of isolated mucosal leishmaniasis in an immunocompetent patient, whose diagnosis mainly rested on histology and positive polymerase chain reaction result for Leishmania donovani in the laryngeal tissue. A 59-year-old man, who never lived outside Italy, showed a subglottic mucosal polypoid-like lesion. The typical morphological picture and positive polymerase chain reaction result for L donovani by DNA extracted from laryngeal biopsy specimens allowed the diagnosis of mucosal leishmaniasis. Specific amphotericin B therapy was started, resulting in clinical and endoscopic improvement. Increased knowledge about the histological and molecular tissue analysis of Leishmania enhances the diagnostic testing for mucosal leishmaniasis, as primary mucosal leishmaniasis may occur in both immunosuppresed and immunocompetent patients who travel to or reside in areas endemic for Leishmania.     

Development and characterisation of neutralising monoclonal antibody to the SARS-coronavirus

There is a global need to elucidate protective antigens expressed by the SARS-coronavirus (SARS-CoV). Monoclonal antibody reagents that recognise specific antigens on SARS-CoV are needed urgently. In this report, the development and immunochemical characterisation of a panel of murine monoclonal antibodies (mAbs) against the SARS-CoV is presented, based upon their specificity, binding requirements, and biological activity. Initial screening by ELISA, using highly purified virus as the coating antigen, resulted in the selection of 103 mAbs to the SARS virus. Subsequent screening steps reduced this panel to seventeen IgG mAbs. A single mAb, F26G15, is specific for the nucleoprotein as seen in Western immunoblot while five other mAbs react with the Spike protein. Two of these Spike-specific mAbs demonstrate the ability to neutralise SARS-CoV in vitro while another four Western immunoblot-negative mAbs also neutralise the virus. The utility of these mAbs for diagnostic development is demonstrated. Antibody from convalescent SARS patients, but not normal human serum, is also shown to specifically compete off binding of mAbs to whole SARS-CoV. These studies highlight the importance of using standardised assays and reagents. These mAbs will be useful for the development of diagnostic tests, studies of SARS-CoV pathogenesis and vaccine development.     

Electrical properties of gap junction channels in guinea-pig ventricular cell pairs revealed by exposure to heptanol

Cell pairs were isolated from adult guinea pig ventricles to study the electrical properties of gap junction channels. The experiments involved a double voltage-clamp approach and whole-cell, tight-seal recording. Heptanol decreased the intracellular current, In, in a dose-dependent fashion. Before complete uncoupling, In showed fluctuations suggesting the operation of gated channels. In the presence of 3 mM heptanol, In showed quantal steps arising from spontaneous opening and closing of single channels. The IV-relationship of the channels was linear (range: +/- 95 mV). Analysis of current records revealed the following single-channel conductances, gamma n: Mean value = 37 pS; median value = 33 pS. gamma n was insensitive to the non-junctional membrane potential (range: -90 to +10 mV). 3 mM ATP4- in the pipette solution had no effects on gamma n, 6 mM ATP4- produced a small decrease, and 6 mM ATP + 0.1 mM cAMP- an increase in gamma n. Channel transitions from closed to open state were variable (range of apparent time constants: 2.5-32 ms; mean: 11 ms).     

High-conversion emulsion polymerization

The four important factors that determine the rate of emulsion polymerization are the propagation rate coefficient, the latex-particle concentration, the monomer concentration in the latex particles, and the free-radical concentration in the latex particles. Both theoretical considerations and experimental evidence suggest that the important factors that may reduce the rate of emulsion polymerization at high conversion are the propagation rate coefficient and the monomer concentration in the latex particles, and not the free-radical concentration in the latex particle, if the initiator is not depleted. Various approaches for increasing the rate of emulsion polymerization at high conversion are suggested.