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Biomedical subjects

G Walter

Publications and source records attributed to G Walter.

At least 109 records · Page 6Linked to original sources
PubMed1995

On the morphological diagnostics and host specificity of the Sarcocystis species of some domesticated and wild bovini (cattle, banteng and bison).

Sarcocysts of Sarcocystis cruzi, S. hominis and S. hirsuta were described and compared by means of light (LM) and transmission electron microscopy (TEM) from cattle, bantengs (born in a zoo) and bisons (born in zoo). No morphological differences were observed in the three forms of sarcocysts from each of the three host species. The morphological criteria of the three species were discussed and, partly, newly defined. S. cruzi can easily be distinguished from the other two species. It shows 6-13 micron long hair-like villar protrusions in the freshly extracted sarcocyst, has large compartments often bump-like bulged out (by LM, in the fresh state), and a "thin cyst wall" ( < 1 micron; LM, histology). TEM investigation is not necessary in most cases. S. hominis and S. hirsuta: with a "thick, radially striated" and 2.5-9.0 micron high cyst wall (LM). S. hominis can be most reliably determined by means of TEM: the villar protrusions arise with a broad basis from the cyst surface, are finger-like in the outline and have microfilaments in the core. LM: the villar protrusions are broadly seated on the cyst surface, without optical interruption. Likewise, S. hirsuta can be determined most reliably by TEM (in some cases also in semithin sections): the villar protrusions are club- or bulb-shaped in the outline, with a stalklet at the base and with microfilaments and large osmiophilic granules in the interior. LM (best in the fresh state): the palisade of villar protrusions often shows a bright or dotted horizontal line in the middle and a basal line with dark dots, arranged like a string of pearls.

Animals↗
PubMed1994

Studies on human porin. XII. Eight monoclonal mouse anti-"porin 31HL" antibodies discriminate type 1 and type 2 mammalian porin channels/VDACs in western blotting and enzyme-linked immunosorbent assays.

Eight mouse monoclonal antibodies directed against the acetylated N-terminal part of the type 1 human VDAC Porin 31HL clearly discriminate type 1 and type 2 mammalian porin channels. This is shown by comparing synthetic N-terminal peptides of either channel type in Western dot blots or by ELISA. The data support the specificity of the anti-Porin 31HL antibodies and thus give further support to our recent observations on extramitochondrial expression of VDAC. In the plasmalemma of different mammalian cells VDAC forms part of an ubiquitous chloride channel complex, which in patch clamp measurements may figure as the outwardly rectifying depolarization-induced chloride channel that is affected in cystic fibrosis.

Amino Acid Sequence↗
PubMed1994

Sarcocysts (Sarcocystis sp.: Sporozoa) in the European badger, Meles meles.

Sarcocysts from the tongue muscle of a European badger (Meles meles) are reported for the first time and described by light and transmission electron microscopy. Judging from the ultrastructure of the cyst wall, the parasite is similar to the species Sarcocystis gracilis Rátz, 1909 sensu Erber, Boch & Barth (1978) from roe deer and possibly identical with it. This is noteworthy regarding the intermediate host specificity.

Animals↗
PubMed1994

A map of the human immunoglobulin VH locus completed by analysis of the telomeric region of chromosome 14q.

Analysis of the telomeric region of chromosome 14q has enabled us to complete a map of the immunoglobulin VH locus which accounts for almost all VH segments known to rearrange in B-lymphocytes. The human germline VH repertoire consists of approximately 50 functional VH segments--the exact number depending on the haplotype--spanning 1,100 kilobases upstream of the JH segments. A yeast artificial chromosome used to map these segments was isolated by its ability to provide telomere activity in yeast, suggesting that the VH locus may be located within a few kilobases of the 14q telomere. The limited structural diversity encoded by the functional VH segments demonstrates the importance of combinatorial diversity produced by VDJ joining and the association of heavy and light chains in producing the human antibody repertoire.

Amino Acid Sequence↗
PubMed1994

Human immunoglobulin VH and D segments on chromosomes 15q11.2 and 16p11.2.

In addition to the major human immunoglobulin heavy-chain locus on chromosome 14q32.3, VH and D segments are known to be present on chromosomes 15 and 16. We have now amplified and sequenced 24 such VH segments from somatic cell hybrids and have assigned them to 15q11.2 and 16p11.2 using cosmid and yeast artificial chromosome clones. In addition, we have located a cluster of D segments on 15q11.2, previously thought to be located on 14q32.3. We propose that the segments on chromosome 16 arose by an interchromosomal duplication and identify the corresponding region on chromosome 14. Taken together with the completion of a map of the human VH locus on 14q32.3, the total number of VH segments now identified is 117. We can now account for most, if not all human germ-line VH segments.

Base Sequence↗
PubMed1994

Molecular model of the A subunit of protein phosphatase 2A: interaction with other subunits and tumor antigens.

Protein phosphatase 2A consists of three subunits, the catalytic subunit (C) and two regulatory subunits (A and B). The A subunit has a rod-like shape and consists of 15 nonidentical repeats. It binds the catalytic subunit through repeats 11 to 15 at the C terminus and the tumor antigens encoded by small DNA tumor viruses through overlapping but distinct regions at N-terminal repeats 2 to 8. A model of the A subunit was developed on the basis of the fact that uncharged or hydrophobic amino acids are conserved at eight defined positions within each repeat. Helical wheel projections suggested that each repeat can be arranged as two interacting amphipathic helixes connected by a short loop. Mutational analysis of the A subunit revealed that the proposed loops are important for binding of tumor antigens, the B subunit, and the C subunit. Native gel analysis of mutant A subunits synthesized in vitro demonstrated that the binding region for the B subunit, previously thought to include repeats 2 to 8, covers repeats 1 to 10 and that the B and C subunits cooperate in binding to the A subunit.

Amino Acid Sequence↗
PubMed1994

Student opinion formation on animal agriculture issues.

Agriculture and animal science student bodies are shifting toward a more urban composition at the same time that criticism of animal industries by nonagricultural groups is increasing. Animal science classes include students with diverse educational goals, agricultural knowledge and experience, and values. Students without agricultural backgrounds or who have not formed opinions on agricultural questions may lack the integrated knowledge that motivates them to seek, organize, and retain the technical subject matter presented in their animal science courses. A survey of undergraduates in animal science and other agriculture majors indicates that significant numbers are unable or unwilling to offer opinions on questions related to critical social issues facing animal agriculture. Opinion holding among animal science majors and non-majors was relatively similar. However, students from urban backgrounds were less likely than rural students to offer opinions, and many of those who offered opinions held views different from those of students from rural backgrounds. Students reporting recent exposure to the issue in their academic course work were somewhat more likely to hold opinions. The findings are consistent with a social-psychological learning model that suggests instructors should require students to express and defend positions on agricultural issues in course activities.

Adult↗
PubMed1994

The wisent (Bison bonasus, Bovidae) as an intermediate host of three Sarcocystis species (Apicomplexa: Sarcocystidae) of cattle.

Sarocysts were found in muscle tissue of a wisent (Bison bonasus) which was born and kept in Germany. Light microscopic and TEM examination revealed all the three named species known from cattle: Sarcocystis cruzi ("thin-walled", with longer hair-like villar protrusions of the primary cyst wall); S. hirsuta ("thick-walled", with tongue-like protrusions of the cyst wall arising with very short and narrow stalklets from the surface of the cyst and containing rows of electron-dense granules in the core); and S. hominis ("thick-walled", with finger-like protrusions of the cyst wall not constricted at their base and containing few or no electron-dense granules). So far, only S. cruzi was known to occur in Bison bison in North America. The findings in the wisent strikingly support a modified conception of the intermediate host specificity in Bovinae. In this connection the identity of S. cruzi and S. poephagicanis is suggested as well as that of S. hirsuta and S. poephagi.

Animals↗
PubMed1994

[Ambulatory short-term therapy of anxiety patients with autogenic training and hypnosis. Results of treatment and 3 months follow-up].

The aim of the study was to examine the effects of a short-term outpatient treatment (6 sessions à 90 minutes) with autogenic training (Schultz 1932) or hypnosis (Erickson and Rossi 1979), concerning patients with anxiety- and panic disorders (according to DSM-III-R and ICD-10-criteria). 27 Outpatients were recruited by newspaper articles. Most of them had not been treated before. Both short-term treatments consisted of 6 weekly group sessions (4-6 patients). Psychological examinations were carried out before and after treatment and at a follow-up after 3 months. Trait anxiety (STAI-X2) and psychosomatic complaints (BfS/BL') decreased in both groups significantly after treatment. This therapeutic effect was stable during the following 3 months. The frequency of panic attacks decreased as well under treatment, and this effect was even more marked during the 3 month following treatment. The therapeutic success was influenced by the frequency of autosuggestive exercises carried out by the patients at home. This form of short-term treatment is not sufficient for all patients with anxiety disorders but the results of that study encourage to use short-term interventions with autogenic training and hypnosis as initial therapeutic approaches for such patients and to combine them with other therapeutic interventions.

Adult↗
PubMed1993

HAPPY mapping of a YAC reveals alternative haplotypes in the human immunoglobulin VH locus.

We have identified and sequenced 14 human immunoglobulin VH segments cloned in a yeast artificial chromosome, and have used a rapid PCR-based technique (HAPPY mapping, 12) to derive the order and approximate distances between them. The sequences mapped comprise thirteen germline VH segments and one rearranged VH3 gene. Comparison of our map with other data suggests the existence of at least two distinct haplotypes, differing in the presence or absence of the consecutive genes DP-78, DP-46 and DP-64, and in the duplication of segments DP-49 and DP-65. Screening of ten individuals confirms the existence of both haplotypes, and indicates that both are common amongst the population.

Base Sequence↗
PubMed1993

Nerve reconstruction with glycerol-preserved allogenic grafts in the rat.

A variety of materials have been evaluated as potential nerve grafts. To date, none has been shown to be consistently equal with regard to functional outcome when compared to standard autogenous nerve grafts. In this study, nerves stored in glycerol were evaluated for their peripheral nerve regenerative capacity. Femoral nerves were harvested from Fischer rats and stored for a minimum of 100 days in 98% glycerol at 4 degrees C. They were grafted into femoral nerve gaps of Lewis rats. After 3 months, histologic, electrophysiologic, and morphometric (axon diameter) analyses revealed less regenerative response than nerve gaps grafted with fresh, syngeneic controls. The differences disappeared by 6 months, although neither graft technique achieved recovery comparable to unoperated nerves. Immunohistochemical evaluation demonstrated a modest immune response at 3 months, which subsided by 6 months. These findings are encouraging for the development of glycerol-preserved nerve graft banking.

Action Potentials↗
PubMed1993

Alcohol and drug treatments in Australian correctional services.

A comprehensive literature review on the subject of drug and alcohol treatments in correctional services reveals the size of the drug and alcohol problem within the prison population and reconfirms the positive correlation between drugs, alcohol and criminal activity. Disturbingly few comprehensive ongoing assessment and treatment services are available for the prison population. Special drug and alcohol-related issues such as HIV and hepatitis B infection, and high drug-related post-release prisoner mortality rates demand an urgent review of the policies and procedures concerning the assessment and treatment of drug and alcohol problems in correctional facilities.

Journal Article↗