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Biomedical subjects

M Haas

Publications and source records attributed to M Haas.

At least 289 records · Page 16Linked to original sources
PubMed1984

Complement activation in patients at risk of developing the adult respiratory distress syndrome.

In this prospective study of 50 patients, 36 of whom developed the adult respiratory distress syndrome (ARDS), early and intense complement activation was demonstrated. These patients were at risk of the ARDS because of multiple injuries, major abdominal surgery, acute pancreatitis, severe burns, or disseminated intravascular coagulation. Abnormal C3 consumption (as measured by the C3d/C3 ratio) and elevated plasma C5a-like activity (as measured by a leukocyte aggregation assay) were associated with, respectively, 84 and 86% of cases of ARDS. Both tests were more sensitive indicators of complement consumption than were assays of total hemolytic complement activity (CH50) or total C3. The C3d/C3 ratio showed a close, inverse correlation with CH50 in 47 healthy subjects, and was increased in 12 control patients after minor surgery. The C5a-like activity was found only in patients at risk of ARDS; it was highly associated with clinical conditions that predispose to the ARDS, but it cannot be considered as a real predictor of ARDS occurrence in these patients. Sequential samples from both sides of the pulmonary circulation showed initial pulmonary clearance followed by the release of C5a-like activity. No simultaneous changes in C3 levels were found, suggesting the possible presence of modulating factors. These observations suggest that other factors (e.g., hypoxia and metabolic cascades) may influence the development of ARDS.

Complement Activation↗
PubMed1984

Cold light sources. Are they really cold?

Two light sources used in laparoscopy, both in the photo mode, proved capable of burning a hole in a standard paper surgical drape in less than five seconds. The relationship between power (in watts) and dial settings is not linear. Both of these sources have a maximum power density of 5.6 w/cm2, which far exceeds the 1.8 w/cm2 power density of the other light sources tested. Today, with the demand for increased illumination for photodocumentation , the physician must be cognizant of its potential hazards. Light sources will vary according to the type of source--tungsten, halogen or mercury arc. Each increase in wattage output will transmit a greater cable power density. Equipment should be checked for its potential to produce burns in routine use and, if defective, should be replaced.

Equipment Safety↗
PubMed1983

The dissociation of the exaggerated prolactin and thyrotropin responses in seminiferous tubule failure following the administration of a double-pulse of thyrotropin-releasing hormone.

PRL and TSH secretion has been evaluated in 11 patients with seminiferous tubule failure and 9 controls. When compared to the controls, the patients had increased basal FSH, TSH and PRL levels. However, LH, E2, T and thyroid hormone levels were similar to the controls. Both groups were given two pulses of TRH (200 micrograms) at 30 min intervals. Following the initial pulse of TRH, the patients demonstrated exaggerated TSH and PRL responses. The administration of a second pulse of TRH led to a further increment of TSH secretion in the patients. There was, however, no PRL response to the second TRH pulse in either patients or controls although mean PRL levels remained significantly greater in the patients.

Adult↗
PubMed1983

Chromosomal mapping of the mink cell focus-inducing and xenotropic env gene family in the mouse.

Chromosomal locations of members of the xenotropic-related env gene family in the mouse genome have been determined. Endonuclease restriction site polymorphisms detected by molecular hybridization were used to study the inheritance of mink cell-focus inducing and xenotropic env gene-related sequences in recombinant inbred strains of mice. Some of the endogenous env sequences appear to be closely linked to genes determining leukemia virus induction and to genes involved in the immune response, such as the heavy and light chains of the immunoglobulin molecules or allotypic determinants on B and T lymphocytes. The use of probes that detect restriction fragment length polymorphisms in a small family of dispersed sequences promises to yield a large number of markers that can be used together with recombinant inbred strains for efficient mapping of the mouse genome.

Animals↗
PubMed1983

Elimination of endogenous xenotropic retroviruses from peritoneal macrophages in virus-induced T cell lymphoma.

Peritoneal macrophages did not support the replication of 136 . 7 and 4SP, T cell lymphoma-inducing viruses, either in vivo or in vitro. Interestingly, endogenous xenotropic viruses, which were detected in more than 50% of the tested samples of peritoneal macrophages of normal C57BL/6 mice, were eliminated from peritoneal macrophages removed from 136 . 7- or 4SP-inoculated, T cell lymphoma-bearing mice. This elimination occurred about 2 weeks after virus inoculation. X-irradiation (400 rads) seemed to accelerate the elimination of xenotropic viruses from the peritoneal macrophages of mice inoculated with the radiation-dependent variant, the 4SP virus. The significance of this elimination of viruses from macrophages following inoculation with T cell lymphoma-inducing viruses is discussed.

Animals↗
PubMed1983

The interrelationships between prolactin and thyrotrophin secretion following dopaminergic blockage in patients with mild hyperprolactinaemia without any demonstrable pituitary tumour.

PRL, TSH and gonadotrophin responses to the dopaminergic antagonist, metoclopramide, were studied in mildly hyperprolactinaemic patients with normal sella radiology and CT scan. Eleven female patients with basal PRL levels ranging from 23 to 124 ng/ml were challenged with intravenous metoclopramide (10 mg) and on subsequent occasions with TRH (200 micrograms) and LHRH (100 micrograms). On the basis of the PRL secretory pattern following metoclopramide and TRH stimulation, the patients were divided into two groups. Group I comprised six subjects who were PRL non-responsive to TRH and metoclopramide. Group II (five subjects) demonstrated PRL responses to TRH and metoclopramide indistinguishable from female controls. Mean +/- SD basal PRL levels were 68.5 +/- 29.9 ng/ml in Group I and not different in Group II (40.6 +/- 12.0 ng/ml). Basal LH levels were increased in Group II, whereas FSH was increased in Group I. Basal TSH levels were lower in Group I than the controls. Following metoclopramide, Group I patients had an increase in TSH from a basal of 2.4 +/- 0.7 microU/ml to a peak of 5.9 +/- 2.7 microU/ml (P less than 0.005) which occurred at 30 min. TSH values were increased above basal at all time intervals following metoclopramide. In contrast, TSH levels did not change in Group II patients or the controls after metoclopramide administration. Both patient groups had TSH responses to TRH similar to the controls. Following LHRH, the LH increase was greater in Group II and the FSH in Group I. In neither group nor the controls did gonadotrophin levels change after metoclopramide. In Group II females, PRL responsiveness to metoclopramide was associated with TSH non-responsiveness. In Group I females, PRL levels failed to rise, whereas TSH increased. The PRL and TSH profile in Group I females is typical of a prolactinoma. It is concluded that PRL as well as TSH determinations following metoclopramide are useful indices in the assessment of hyperprolactinaemia and may be of value in differentiating the functional state from that of a pituitary tumour.

Adult↗
PubMed1983

Bumetanide inhibits (Na + K + 2Cl) co-transport at a chloride site.

Chloride-dependent cation transport systems in a number of cells and tissues are inhibited by 5-sulfamoylbenzoic acid loop diuretics, such as furosemide and bumetanide. Interactions between chloride and bumetanide have been examined in the catecholamine-activated (Na + K + 2Cl) co-transport pathway of the duck red blood cell. Levels of chloride were varied while maintaining a constant ratio of internal to external chloride across the cell membrane. Increasing external chloride from 20 to 100 mM shifted the dose-response curve for the effect of bumetanide on co-transport toward higher concentrations of the drug. The bumetanide concentration producing half-maximal inhibition (IC50) was increased from approximately 6 X 10(-8) to approximately 2 X 10(-7) M. When cells were incubated in the presence of a constant, submaximal inhibitory dose of bumetanide (10(-8) M), increasing external chloride (in increments of 20 mM) from 20 to 140 mM progressively decreased the level of inhibition of the co-transport system. Kinetic analysis of the data demonstrates that bumetanide and chloride compete for a common site.

Animals↗
PubMed1983

Cognitive vulnerability to auditory hallucination. Preferred imagery mode and spatial location of sounds.

Goldstone and Sarbin proposed that auditory hallucinations occur because imagery in a non-preferred sensory mode is more easily misinterpreted as having an external origin. This led to the hypothesis that auditory hallucinators would show less preference for auditory than for visual imagery. Our results suggest that this is true. We also compared the vividness of internally-generated auditory imagery with that of visual imagery, independently of preference, to see whether vividness was impaired in the nonpreferred mode in hallucinators. The evidence suggested that this was not the case, but we did find a significantly deficient capacity for creating vivid images of either kind in process patients (i.e. those with poor premorbid status) compared with reactive (good premorbid) patients, regardless of any history of hallucinations. The withdrawal of external attention which characterizes process patients might also be expected to impair their ability to confirm or disconfirm the external origin of an auditory stimulus. We predicted therefore that process hallucinators would be particularly incompetent in spatial location of sounds: our experimental results confirmed this to be the case.

Adult↗
PubMed1983

Interaction of neurotensin, cholecystokinin, and secretin in the stimulation of the exocrine pancreas in the dog.

The effects of exogenous neurotensin, secretin, and cholecystokinin-33 alone and in combination on pancreatic secretion were investigated in dogs prepared with pancreatic fistulae. Neurotensin infused intravenously caused a dose-dependent stimulation of exocrine pancreatic secretion. Increasing doses of neurotensin combined with a constant small dose of secretin potentiated pancreatic output of protein and had a tendency to reduce secretion of the bicarbonate. Increasing doses of neurotensin combined with a constant small dose of cholecystokinin-33 potentiated pancreatic output of bicarbonate and lead to a reduction (insignificant) of pancreatic protein secretion. These observations suggest an interaction of neurotensin with pancreatic receptors for secretin and cholecystokinin.

Animals↗
PubMed1982

Involvement of peritoneal macrophages and spleen stromal cells in X-irradiation-induced reticulum cell neoplasms in C57BL/6 mice.

Some correlation was observed between the occurrence of FA-positive PE-MO and spleen stromal cells (removed from X-irradiated RCN-bearing old-adult B6 mice) and the generation of RCN. No significant correlation was found between the viral content of lymphoid organs from the same mice and the occurrence of RCN. The main viral particle detected in lymphoid organs from radiation-induced RCN-bearing mice was the xenotropic virus. Ecotropic viruses were detected in a few spleens and Payer patches from such mice. These ecotropic viruses showed very poor lymphomagenic activity and required 400R X-ray as a cofactor. No dualtropic viruses were detected. However, inoculation of ecotropic (SFA2) helper virus to X-irradiated old-adult B6 mice, resulted in an efficient rescue of lymphomagenic viruses, enriched with phenotypically mixed, dualtropic viruses. Some of these DT viral preparations were cloned and seemed to consist mainly of xenotropic sequences. Thus, inoculation of helper viruses influenced the generation and selection of DT viruses. Such viral preparations, enriched with DT viruses, had a better lymphomagenic activity compared to endogenous ecotropic viruses, isolated from radiation-induced RCN-bearing mice. Indirect evidence suggested the involvement of a defective (xenotropic and possibly adjacent cellular genes) particle in lymphoma induction. To conclude, a possible mechanism for the development of radiation-induced RCN is suggested, emphasizing the role of MO in such a process.

Animals↗
PubMed1982

Catecholamine-stimulated ion transport in duck red cells. Gradient effects in electrically neutral [Na + K + 2Cl] Co-transport.

The transient increase in cation permeability observed in duck red cells incubated with norepinephrine has been shown to be a linked, bidirectional, co-transport of sodium plus potassium. This pathway, sensitive to loop diuretics such as furosemide, was found to have a [Na + K] stoichiometry of 1:1 under all conditions tested. Net sodium efflux was inhibited by increasing external potassium, and net potassium efflux was inhibited by increasing external sodium. Thus, the movement of either cation is coupled to, and can be driven by, the gradient of its co-ion. There is no evidence of trans stimulation of co-transport by either cation. The system also has a specific anion requirement satisfied only by chloride or bromide. Shifting the membrane potential by varying either external chloride (at constant internal chloride) or external potassium (at constant internal potassium in the presence of valinomycin and DIDs [4,4'-diisothiocyano-2,2'-disulfonic acid stilbene]), has no effect on nor-epinephrine-stimulated net sodium transport. Thus, this co-transport system is unaffected by membrane potential and is therefore electrically neutral. Finally, under the latter conditions-when Em was held constant near EK and chloride was not at equilibrium-net sodium extrusion against a substantial electrochemical gradient could be produced by lowering external chloride at high internal concentrations, thereby demonstrating that the anion gradient can also drive co-transport. We conclude, therefore, that chloride participates directly in the co-transport of [Na + K + 2Cl].

Animals↗
PubMed1982

Immunopathology of B-cell lymphomas induced in C57BL/6 mice by dualtropic murine leukemia virus (MuLV).

Combined clinicopathologic and immunomorphologic evidence is presented that would indicate that a murine leukemia virus (MuLV) with the dualtropic host range is capable of producing a clinically malignant lesion composed of immunoblasts and associated plasma cells in C57BL/6 mice. This process, morphologically diagnosed as an immunoblastic lymphoma of B cells using standard histopathologic criteria, was found to be distinctly polyclonal with regard to immunoglobulin (Ig) isotype when analyzed for both surface and cytoplasmic Ig. Further studies demonstrated that this clinicopathologically malignant, dualtropic MuLV-induced, polyclonal immunoblastic lymphoma of B cells in C57BL/6 mice was normal diploid and unable to be successfully transplanted to nonimmunosuppressed syngeneic recipients. Although all serum heavy and light chain components were found to be progressively elevated as the tumor load increased, the polyclonal increase in serum immunoglobulins was most pronounced for mu heavy and kappa light chains (ie, mu greater than gamma 2A greater than alpha greater than gamma 2B greater than gamma 1; kappa greater than lamba). The dissociation of clinicopathologic and biologic criteria for malignancy in the presently described dualtropic (RadLV) MuLV-induced B-cell lesion is sharply contrasted with the thymotropic (RadLV), MuLV-induced T-cell lymphoblastic lymphoma in C57BL/6 mice. This process is also a clinicopathologically malignant lesion but, when one uses biologic criteria, is found to be distinctly monoclonal, aneuploid, and easily transplanted to nonimmunosuppressed syngeneic recipients. The close clinicopathologic and biologic similarities of the dualtropic MuLV-induced animal model to corresponding human B-cell lymphoproliferative diseases are stressed.

Animals↗
PubMed1981

Effect of neurotensin on regional intestinal blood flow in the dog.

The effects of various doses of synthetic neurotensin on regional blood flow in different tissue layers of the stomach, small bowel, colon, pancreas, brain, kidneys, adrenal gland, and heart of six dogs was studied using an isotope microsphere technique. Infusion of high doses (20, 40 pmol/kg . min(-1)) of exogenous synthetic neurotensin caused an increase of blood flow in the "muscularis" of duodenum, jejunum, ileum, and colon. Neurotensin infused in a dose (2.5 pmol/kg . min(-1)) raising neurotensin plasma levels to concentrations comparable to those observed after a meal caused an increase of blood flow in the muscular layer in ileum. Our results suggest that one of the physiologic actions of neurotensin may be the regulation of blood flow in the muscular layer of the ileum.

Animals↗
PubMed1980

Cell-surface antigens associated with dualtropic and thymotropic murine leukemia viruses inducing thymic and nonthymic lymphomas.

Unique type-specific antigens were detected on cells infected with dualtropic and thymotropic viruses isolated and x-ray-induced T cell- and B cell-malignant lymphomas of C57BL/6 mice. These antigens were defined by membrane fluorescence with antisera made in rabbits against rabbit cells chronically infected with cloned virus. The antisera were qualitatively absorbed with a group of cells chronically infected with related dualtropic, ecotropic, and xenotropic viruses. The absorbed antisera detected type-specific, virus-related cell-surface antigens that were unique for different dualtropic virus isolates. The unabsorbed sera also reacted with antigens found specifically on ecotropic and xenotropic virus-infected cells. These findings support the contention that T cell lymphoma (TCL)-inducing and B cell lymphoma (BCL)-inducing viruses isolated from x-irradiated C57BL/6 mice are env gene recombinants in which ecotropic gene sequences have been substituted by xenotropic sequences. We found that unique antigenicities are associated with each TCL-inducing and BCL-inducing dualtropic virus, and that the thymotropic TCL-inducing virus isolates (e.g., 136.5 adn 136.7 viruses) represent a separate serologic group, different from the dualtropic TCL-inducing viruses. By using a series of absorbed antisera in microimmunofluorescence tests we could perform serologic virus mapping of dualtropic clones isolated by us or by others and relate them serologically to previously isolated clones. These virus mapping experiments indicated that many serologically different recombinant viruses can be isolated from C57BL/6 mice. It is suggested that many distinct recombinant viruses may exist in lymphomagenic C57BL/6 mice, some of which are associated with specific lymphoma induction.

Animals↗