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Biomedical subjects

H Gerlach

Publications and source records attributed to H Gerlach.

At least 19 recordsLinked to original sources
PubMed1992

Further investigations on Pasteurella multocida infections in feral birds injured by cats.

A total of 64 Pasteurella multocida strains (46 out of 11 different feral bird species, partly injured by cat bites, and 18 strains originating from clinically healthy cats) were biochemically differentiated. As a result, 67.4% of the strains from feral birds and 61.1% from the cats were classified as the subspecies multocida, whilst 21.7% and 27.8% were identified as the subspecies septica. The percentage of frequency for both the subspecies was of a comparable order of magnitude from the birds injured by cat bites and from cats (58.6% and 61.1%, 24.1% and 27.8% resp.), whereas the frequency from other feral birds differed considerably (82.4% and 17.6%). Maltose-positive strains were only demonstrable in birds with wounds inflicted by cats. To date, maltose-positive strains have only been obtained from one cat and one human being with an injury caused by a cat. The results of this investigation confirm the possibility of the direct transmission of Pasteurella multocida via cat bites. 19 strains from feral birds and 15 strains from cats were tested for their capability to produce toxins. The results of these tests were negative. The present paper also describes the pathologic-anatomical and histopathological lesions caused by the infection in feral birds.

Animals↗
PubMed1992

[The aerobic bacterial flora of songbird nests].

In the area around Ober- and Unterschleissheim, a medium term decrease in the singing bird population appears to be happening. Therefore, material from nesting-boxes (used for nesting or sleeping) was examined for bacterial contamination. Mainly gram positive bacteria were isolated which were considered to belong to the normal flora. The occurrence of Streptomyces spp. is described in the nesting material of Passeres probably for the first time. Enterobacteriaceae represent only a fraction of the total isolates, but are demonstrated relatively frequently in the nests of the Nuthatch (Sitta europaea) and nests of other non-identified bird spp., so that colonization of the intestinal tract with Enterobacteriaceae cannot be excluded. Surprisingly, bacteria of the aquatic habitats such as Alcaligenes, Bordetella, Aeromonas, Non-Cholera (NC)-Vibrio were isolated, although in small amounts. The occurrence of NC-Vibrio has not yet been described in singing birds. Nests with high numbers of gram negative rods were successful in most instances, therefore, there was no proof that aerobic bacteria are responsible for the decrease in the population.

Animals↗
PubMed1992

[An epidemiologic study of the value and limits of physical therapy/exercise therapy in Fontaine stage II arterial occlusive disease].

Using a questionaire the members of the German Society for Angiology (DGA) were interrogated on the use of physical training for the treatment of peripheral arterial occlusive disease; from a total of n = 431 as much as n = 156 responded, i.e. making up a response of 36%. 104 of them conduct physical training either on their own or assign patients to it (67%). In most of the institutions exclusively walking/interval training (83%) or medical exercise (74%) are performed. In most cases the training is conducted by physiotherapeutists (71%). 13% of the patients are admitted exclusively to physical training, 34% undergo combined therapy, i.e. physical training and vaso-active medication. 22% receive mere medical, 31% surgical treatment. A general evaluation on the success of the different therapies applied turned out following frequency: 1. combined therapy (medical treatment/physical training); 2. surgical procedures as a therapeutic measure; 3. physical training; 4. medical treatment. A further study performed at three ambulatory centres offering physical training were to show what kind and to which extent such training is useful. In 34% of the cases (from a total of n = 201 patients with peripheral arterial occlusive disease in state II according to Fontaine) contraindications argue against the application of physical training. From a rest of 66% as much as 36% of the patients refuse to undergo physical training the reasons of which were stated with large transport distances and time problems. The remaining rest accepts the offer, although 24% attend such training only sporadically. The results show that mainly contraindications and insufficient patient compliance account for the fact that only one third of the patients attend physical training. The results are discussed and proposals are made to improve patient compliance.

Aged↗
PubMed1992

[A rare complication of shunt therapy. Metastasis of brain tumors by cerebrospinal fluid drainage].

Shunting of cerebrospinal fluid to extracranial spaces has been a common and effective procedure for symptomatic therapy of hydrocephalus since the fifties. In 1954 the first spreading of tumor cells via a ventriculo-pleural shunt was reported. We are presenting a case of a 10 month old girl with a medulloblastoma of the lower brain stem with spreading of the intracranial tumor through a ventriculoperitoneal shunt. Further 43 cases of the world literature with shunt-associated metastasizing of brain tumors are analysed. The extraneural spreading of tumor cells through shunt tubes must be considered as a possible complication of the shunting procedure.

Cerebellar Neoplasms↗
PubMed1991

[Mycobacteriosis in the hermit ibis (Geronticus eremita)].

The present paper reports on a case of mycobacteriosis in a colony of Hermit-Ibises, in which a so far unknown serovar of Mycobacterium avium-intracellulare has been isolated. The serologic findings in the birds disagree with those of the isolate, a fact that has been mentioned in the literature several times. The hematological and clinical-chemical parameters can hardly be interpreted without knowledge of normal values. However, the high numbers of eosinophiles in the differential smears are striking. The autopsy shows the typical picture of a granulomatous inflammation. The small subserous granulomata of the intestinal wall can be found--in contrast to other birds--lying closely together. Histopathological findings indicate a certain weakness of the defense system which, together with the good state of nutrition in some of the Hermit-Ibises, is interpreted as a possible high susceptibility of this bird species to infections with Mycobacterium spp.

Animals↗
PubMed1991

[Hygienic measures against avian mycobacteriosis in the pheasantry of the Cologne Zoo].

Endemic avian tuberculosis is a constant threat to any bird collection. Controlling measures by serological tests must be supported by both euthanization of positive birds and removal of all contaminated material from the affected enclosures. Quarantine and strict hygienic measures should control reinfection. Reinfection of captive populations through wild birds is comparatively unlikely.

Animals↗
PubMed1991

Endothelium and regulation of coagulation.

Endothelial cells form the luminal vascular surface and thus have a central role in the regulation of coagulation. One important way in which endothelial cells control the clotting system is by regulating the expression of binding sites for anticoagulant and procoagulant factors on the cell surface. In the quiescent state, endothelial cells maintain blood fluidity by promoting the activity of numerous anticoagulant pathways, including the protein C/protein S pathway. After activation, as can be brought about by cytokines, the balance of endothelial properties can be tipped to favor clot formation through coordinated induction of procoagulant and suppression of anticoagulant mechanisms. Tumor necrosis factor suppresses the endothelial anticoagulant cofactor thrombomodulin and induces expression of the procoagulant cofactor tissue factor. Working in concert, these changes can allow fibrin formation to proceed in an inflamed focus but maintain blood fluidity in the surrounding area of normal vasculature. Recent studies suggest that similar changes in endothelial coagulant properties can be induced by advanced glycosylation end products, proteins modified by glucose that accumulate in the vasculature at a rapid rate in diabetic subjects, indicating the potential relevance of these mechanisms in diabetic vascular disease.

Animals↗
PubMed1991

[Avian mycobacteriosis caused by strains not yet identifiable].

This paper reports on a group of strains of Mycobacterium avium-intracellulare recently isolated from various bird species. The strains in question could not be integrated into the known 28 serovars. The host spectrum includes birds of several avian orders. Clinical, serological, pathoanatomical, and histopathological results are being discussed. During observations of the clinical course in some infected birds, it could be shown that the excretion of the agent could cease for several months. The diagnosis of the new group of serovars was possible only by culture. Antibodies of several serovars demonstrated in life birds did not correspond with the isolates. Therefore, these antibodies were interpreted as serological crossreactions.

Animals↗
PubMed1990

Vascular permeability factor: a tumor-derived polypeptide that induces endothelial cell and monocyte procoagulant activity, and promotes monocyte migration.

Systemic infusion of low concentrations of tumor necrosis factor/cachectin (TNF) into mice that bear TNF-sensitive tumors leads to activation of coagulation, fibrin formation, and occlusive thrombosis exclusively within the tumor vascular bed. To identify mechanisms underlying the localization of this vascular procoagulant response, a tumor-derived polypeptide has been purified to homogeneity from supernatants of murine methylcholanthrene A-induced fibrosarcomas that induces endothelial tissue factor synthesis and expression (half-maximal response at approximately 300 pM), and augments the procoagulant response to TNF in a synergistic fashion. This tumor-derived polypeptide was identified as the murine homologue of vascular permeability factor (VPF) based on similar mobility on SDS-PAGE, an homologous NH2-terminal amino acid sequence, and recognition by a monospecific antibody to guinea pig VPF. In addition, VPF was shown to induce monocyte activation, as evidenced by expression of tissue factor. Finally, VPF was shown to induce monocyte chemotaxis across collagen membranes and endothelial cell monolayers. Taken together, these results indicate that VPF can modulate the coagulant properties of endothelium and monocytes, and can promote monocyte migration into the tumor bed. This suggests one mechanism through which tumor-derived mediators can alter properties of the vessel wall.

Amino Acid Sequence↗
PubMed1990

A polypeptide factor produced by fibrosarcoma cells that induces endothelial tissue factor and enhances the procoagulant response to tumor necrosis factor/cachectin.

Intravascular clot formation, localized to the neoplasm, is an early component of the vascular response to tumor necrosis factor (TNF)/cachectin. Fibrin is closely associated with the endothelial cell surface, and multiple microthromboses lead to reduced blood flow in the tumor. We have identified a tumor-derived mediator which enhances endothelial procoagulant activity and the cellular response to TNF using cultured cells derived from a murine methylcholanthrene A (meth A)-induced fibrosarcoma as a model system. A heat-stable protease K-sensitive polypeptide, Mr approximately 44,000 on nonreduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Mr approximately 56,000 reduced), was purified approximately 500,000-fold from serum-free culture supernatants of meth A cells by sequential Q-Sepharose, Mono S, reversed phase, and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Based on immunologic criteria, biologic activity, and other molecular properties, meth A factor appears to be distinct from other cytokines and growth factors. Purified meth A factor induced transcription of the tissue factor gene and expression of procoagulant activity by cultured human endothelium (half-maximal effect for the latter at approximately 6-8 pM). Furthermore, co-incubation of endothelium with meth A factor together with TNF enhanced induction of tissue factor in a more than additive manner. These data indicate that certain tumors elaborate an apparently unique molecule which can alter hemostatic properties of the vessel wall, potentially modulating reactivity of the tumor vasculature to host response mediators.

Animals↗
PubMed1990

[Roxithromycin versus doxycycline in the treatment of cervicitis. Prospective randomized multicenter study under practice-related conditions].

In a prospective randomized multicenter study Roxithromycin 150 mg or Doxycycline 100 mg was given b.i.d. p.o. for ten days to women with clinically diagnosed cervicitis. All women were seen as outpatients by one of eight licensed gynecologists in their private office in the Essen city area. With a cure and improvement rate of 100% in those women who completed therapy, Roxithromycin (n = 106) was as effective as Doxycycline (n = 104; 98%). At 90% Roxithromycin was as well tolerated as Doxycycline at 93%. Both drugs were clinically and microbiologically effective in eradicating Chlamydia trachomatis.

Adult↗
PubMed1990

On the importance of bacterial L-forms in pigeons.

Following a definition of bacterial L-forms and a literature review on introduction and reversion of bacteria to and from L-forms, respectively, the results of a study comprising 587 samples (316 pigeons and 271 pigeon eggs) are reported. As a control 25 free living pigeons and 25 eggs of those pigeons were used, because antibiotic treatment of these could be excluded. From 79 samples (75 pigeons and 4 eggs) Salmonella typhimurium var. copenhagen (STMC) was isolated (none from the urban pigeons), of them 11 in the L-form from joints and organs and 3 from eggs. 325 of other bacterial isolates were found as L-forms (= approx. 40%). Out of 168 serum samples investigated, 33.9% showed antibodies against STMC. Corresponding antibodies could only be demonstrated in 73.4% of the pigeons with a STMC isolate. The occurrence of L-forms explains resistance to therapy and the failure of vaccines. The high frequency of L-forms is probably an indication of an inconsequential use of antibiotics in managing pigeon diseases.

Animals↗
PubMed1990

Modulation of endothelial hemostatic properties: an active role in the host response.

As the cells forming the luminal vascular surface, endothelium regulates both barrier function, and pro- and anticoagulant reactions. Endothelial cells can do this by controlling the expression of cell surface molecules, such as receptors that regulate the hemostatic balance and those that affect permeability across the endothelial monolayer. This regulation occurs in response to environmental stimuli, such as cytokines, which have a central role in inflammation, or glucose-modified proteins, which accumulate in the vasculature in aging and diabetes and are associated with vascular complications. The endothelial cell emerges as a dynamic regulator maintaining homeostasis in the quiescent state and contributing to the pathogenesis of vascular lesions in the stimulated state.

Animals↗
PubMed1990

Hypoxia modulates the barrier and coagulant function of cultured bovine endothelium. Increased monolayer permeability and induction of procoagulant properties.

Exposure of cultured endothelium to environments with low concentrations of oxygen, in the range of those observed in pathophysiologic hypoxemic states in vivo, compromises cellular barrier and coagulant function. An atmosphere with PO2 approximately 14 mm Hg was not lethally toxic to endothelial cultures, but cells became larger and exhibited small intercellular gaps. At low oxygen concentrations, passage of macromolecular tracers through hypoxic endothelial monolayers was accelerated in a time- and dose-dependent manner, presumably by a paracellular pathway via the gaps. Cell surface coagulant properties of the endothelium were also perturbed. At PO2 approximately 14 mm Hg thrombomodulin antigen and functional activity on the cell surface were diminished by 80-90%, and Northern blots demonstrated suppression of thrombomodulin mRNA. The decrease in thrombomodulin was twice as great compared with the general decline in total protein synthesis in hypoxia. In addition, expression of a direct Factor X activator developed under hypoxic conditions; the activator was membrane-associated and expressed on the surface of intact cultures, Ca-dependent, inhibited by HgCl2 but not PMSF, and had Km approximately 25 micrograms/ml for the substrate at pH 7.4. Synthesis of the activator was blocked by inclusion of cycloheximide, but not warfarin, in the culture medium. These results demonstrate that endothelial function is perturbed in a selective manner in the presence of low concentrations of oxygen, providing insights into mechanisms which may contribute to vascular dysfunction in hypoxemic states.

Animals↗
PubMed1989

Endothelial receptor-mediated binding of glucose-modified albumin is associated with increased monolayer permeability and modulation of cell surface coagulant properties.

Advanced glycosylation end products (AGE) of proteins accumulate in the vasculature with diabetes and aging, and are thought to be associated with vascular complications. This led us to examine the interaction of AGE-BSA as a prototype of this class of nonenzymatically glycosylated proteins subjected to further processing, with endothelium. Incubation of 125I-AGE-BSA with cultured bovine endothelium resulted in time-dependent, saturable binding that was half-maximal at a concentration of approximately 100 nM. Although unlabeled normal BSA was not a competitor, unlabeled AGE-BSA was an effective competitor of 125I-AGE-BSA-endothelial cell interaction. In addition, AGE modification of two alternative proteins, hemoglobin and ribonuclease, rendered them inhibitors of 125I-AGE-BSA binding to endothelium, although the native, unmodified forms of these proteins were not. At 37 degrees C, binding of 125I-AGE-BSA or gold-labeled AGE-BSA was followed by internalization and subsequent segregation either to a lysosomal compartment or to the endothelial-derived matrix after transcytosis. Exposure of endothelium to AGE-BSA led to perturbation of two important endothelial cell homeostatic properties, coagulant and barrier function. AGE-BSA downregulated the anticoagulant endothelial cofactor thrombomodulin, and induced synthesis and cell surface expression of the procoagulant cofactor tissue factor over the same range of concentrations that resulted in occupancy of cell surface AGE-BSA binding sites. In addition, AGE-BSA increased endothelial permeability, resulting in accelerated passage of an inert macromolecular tracer, [3H]inulin, across the monolayer. These results indicate that AGE derivatives of proteins, potentially important constituents of pathologic vascular tissue, bind to specific sites on the endothelial cell surface and modulate central endothelial cell functions. The interaction of AGE-modified proteins with endothelium may play an important role in the early stages of increased vascular permeability, as well as vessel wall-related abnormalities of the coagulation system, characteristic of diabetes and aging.

Actin Cytoskeleton↗