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Biomedical subjects

D Weiss

Publications and source records attributed to D Weiss.

At least 73 records · Page 4Linked to original sources
PubMed1993

Practical and effective eradication of pinworms (Syphacia muris) in rats by use of fenbendazole.

Oxyurid parasites are common contaminants of laboratory rodents, and despite many described treatments, no method has assumed preeminence. Limitations in drug efficacy and the general inability to control for exposure to infective eggs are the primary contributors to treatment failure. In addition, some effective drugs must be eliminated from consideration because of narrow safety margins, other toxic aspects, or concerns related to particular uses of the experimental animals. As an alternative to currently described treatments or surgical derivation, we conducted an efficacy study against Syphacia muris in rats with a new fenbendazole-based protocol. Fenbendazole is a highly efficacious broad-spectrum anthelmintic with adulticidal, larvicidal, and ovicidal actions. Its pharmacokinetic behavior, ovicidal activity, and exceptionally wide safety margin in rats and mice make it an attractive choice for pinworm treatment. We used a 150-ppm medicated feed formulation to reach a targeted dose of 8.0 to 12.0 mg/kg/day in three separate studies designed to assess drug intake and efficacy under different housing conditions and in breeding and nonbreeding populations of ACI rats. In all cases, drug was given on alternating weeks, and nonbreeding populations were medicated for a cumulative period of 14 days. The same schedule was used for breeding populations, but the treatment was repeated after a 2-week rest period to ensure sufficient exposure for newly weaned animals. The results of our study indicate that our described treatment, in combination with environmental control measures against pinworm eggs, is capable of eliminating S. muris.

Animals↗
PubMed1992

[Systemic Nocardia infection in an AIDS patient].

We report the case of a patient with Aids, Kaposi's sarcoma and a systemic nocardial infection. After surgical drainage and adequate antibiotic treatment the infection was cured. Under secondary antimicrobial prophylaxis no relapse has occurred to date. Generalized N. asteroides infections have been rarely described in patients with Aids and the possible reasons for this are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Assistance for the aged from the viewpoint of the public health office].

Problems of old age and ways of helping the old were discussed with various social and age groups, among them secondary pupils as well as people living in old people's homes. The main questions which arose were: "How can one give a purpose to one's old age?"--"How does one win sufficient recognition?"--"What can be done to avoid, or overcome, isolation?" Most senior citizens were in favour of spending their old age in their familiar surroundings--either on their own or with their families, in whose life they wanted to participate. Our inquiries have shown that there are more institutions than generally assumed which offer advice and help and can be consulted by those in particular who have decided against living in an old people's home. With the support of other institutions and authorities, the staff of the local Health Service drew up a brochure on "Assistance in Old Age", which covers the Kulmbach area. Then we tried to find ways of improving the quality of our senior citizens' lives without spending too much money. The key issue which emerged was prevention.

Germany↗
PubMed1991

Lifetime and current prevalence of specific psychiatric disorders among Vietnam veterans and controls.

To determine if Vietnam theater veterans were more likely than controls to have a specific psychiatric disorder other than posttraumatic stress disorder, the rates of specific psychiatric disorders were estimated using the Diagnostic Interview Schedule for national samples of veterans who served in Vietnam, other veterans of the Vietnam era, and matched civilian controls. Overall, there were few differences in rates of disorder between theater and other veterans; there were somewhat more differences between theater veterans and civilians. There were striking differences, however, in rates for most disorders, both lifetime and current, between male theater veterans with high levels of exposure to war zone stress and other male veterans or civilians. Female veterans exposed to high levels of war zone stress also had higher rates than other female respondents for several disorders.

Adult↗
PubMed1991

Active lymphatic pumping and sheep lung lymph flow.

Active (intrinsic) lymphatic pumping may be an important factor determining lymph flow from the lungs. Unfortunately, in most experiments, it is very difficult to determine the influence of active pumping vs. passive factors on lymph flow. However, 1) the pumping activity (stroke volume and frequency) of isolated lymphatic segments varies nonlinearly with transmural pressure, and 2) the lung lymph flow from awake sheep varies nonlinearly with lymphatic outflow pressure. Accordingly, if lymphatic pumping significantly influences lung lymph flow, then it should be possible to describe the sheep lung lymph flow vs. outflow pressure data with the pumping activity data. To test this, we used published lymphatic pumping activity data to develop a mathematical model of the lymphatic pump for a segment of lymphatic vessel. Flow vs. outflow pressure relationships obtained from simulations with this model were very similar to the data from sheep. Our results indicate that both passive factors and active lymphatic pumping contribute to lymph flow, and our model may allow investigators to distinguish the effects of active pumping vs. passive factors in the regulation of lymph flow.

Anesthesia↗
PubMed1991

Scavenging of superoxide anion by phosphorylethanolamine: studies in human neutrophils and in a cell free system.

On the basis of previous observations, we attempted to characterize the effects of various products of phospholipid hydrolysis on neutrophil (PMN) respiratory burst activity. We studied the effects of phosphorylcholine (PC) and phosphorylethanoline (PE) on superoxide anion production in PMN and in cell free system. We found that PE but not PC inhibited measured superoxide anion, but that this was not due to inhibition of cellular superoxide generation but to scavenging of generated superoxide anion. Further, utilizing a system based upon the photo-oxidation of O-dianisidine sensitized by riboflavin, we were able to determine that the scavenging effect of PE was not superoxide dismutase (SOD)-like but rather a general scavenging or glutathione (GSH)-like effect. These data underscore the importance of identifying the mechanism of inhibition of superoxide generation by putative inhibitors as being due to a direct cellular effect or to a scavenging property.

Cell-Free System↗
PubMed1991

Infectious imaging with indium-111-labeled nonspecific polyclonal human immunoglobulin.

Nonspecific polyclonal immunoglobulin (IgG), prepared from pooled human serum gamma globulin and labeled with 111In has been reported to be equivalent to antigen-specific antibody in the detection of focal infection or inflammation during the first 24 hr after injection. We describe our experience in a Phase II clinical study using 111In-IgG in 15 patients (8 males, 7 females) ranging from 26 to 80 (mean = 50) yr of age with suspected focal infection/inflammation. Pathologic confirmation was obtained in 5/15 cases. A combination of clinical course, laboratory results, and other imaging procedures were used to categorize the other 10 patients. One possible false-negative involved a presumed aspiration pneumonia in a patient with a history of aspiration, bibasilar infiltrates on chest film, and no other identified source of infection. Otherwise, there were 10 confirmed positives, 4 confirmed negatives, and no false-positives. Our findings confirm earlier reports that 111In-IgG may be a superior imaging agent for infection/inflammation with practical advantages over 67Ga-citrate and 111In-labeled leukocytes.

Drug Evaluation↗
PubMed1990

A murine model for B-cell lymphomagenesis in immunocompromised hosts: c-myc-rearranged B-cell lines with a premalignant phenotype.

Activation of c-myc or bcl-2 protooncogene is a common event in B-cell lymphomagenesis. Alone, each is insufficient to produce lymphoma, prompting the search for the additional steps required to complete the malignant phenotype. Among the existing systems of murine or human B-cell neoplasia, no commonly occurring complementary oncogenic activation has been found. This study introduces a new series of murine B-cell lines with a phenotype suggesting that such additional events might not involve intrinsic growth control, but instead host immune mechanisms which normally suppress tumorigenicity of premalignant B-cells. Four murine B-cell lines were isolated from the long-term culture of normal lymphoid tissue bearing a premalignant phenotype. (a) Their phenotype resembled naturally occurring lymphoid tumors of immunocompromised hosts with regard to c-myc activation, aberrant or absent immunoglobulin expression, preferential rearrangement of the lambda light chain locus, and a distinctive pattern of tissue invasion and tumor histology. (b) Their tumorigenicity was strictly dependent on host permissiveness correlated with immunodeficient status: C.B-17-scid greater than BALB/c-nu/nu greater than normal BALB/c much greater than other H-2d strains (NZB x NZW F1, NZB, DBA/2). (c) Host passage selected for malignant variants distinguished by a 10(4)-fold increase in tumorigenicity (as judged by limiting cell dose) and by novel tumorigenicity in nonpermissive syngeneic hosts. These features are analogous to properties of human lymphomas arising in immunocompromised states and, to our knowledge, unique among previously reported murine B-cell lines.

Animals↗