Proctolin-related material in the mouse brain as revealed by immunohistochemistry

By use of a specific antiserum against the insect peptide proctolin we were able to identify proctolin-immunoreactive neurons in the mouse brain. These nerve cells belong to the nuc. mesencephalicus n. trigemini. Furthermore, the antiserum stained very few nerve fibers with varicosities in the immediate neighborhood of the roof of the third ventricle. The chemical identity of the immunoreactive material with genuine proctolin remains to be elucidated.     

Angiostrongylose bei Mensch und Tier

Zusammenfassung Die vorliegende Arbeit gibt eine Übersicht über den Stand der Angiostrongylose-Forschung. Von den bisher bekannten 16 Angiostrongylus-Arten haben drei eine medizinische Bedeutung: Der Rattenparasit A. cantonensis (Chen, 1935), Dougherty 1946 ist im südostasiatisch-pazifischen Raum Erreger einer eosinophilen Meningoenzephalitis des Menschen. A. costaricensis Morera und Céspedes, 1971, eine kürzlich in Costa Rica bei Haus- und Baumwollratten festgestellte Art, kann sich in den Mesenterialgefäßen des Menschen ansiedeln und Gefäßthrombosen und Darmentzündung hervorrufen. Eine Humanpathogenität des Fleischfresserparasiten A. vasorum (Baillet, 1866) läßt sich nach den heutigen Kenntnissen nicht ausschließen; als Ursache für zentralnervöse Erkrankungen des Menschen kommt dieser Parasit jedoch höchstwahrscheinlich nicht in Betracht, da die Larven auch im spezifischen Endwirt nicht in das Zentralnervensystem einwandern. Über A. vasorum werden folgende, zum Teil unveröffentlichte Forschungsergebnisse mitgeteilt: In der Schweiz wurden Fälle autochthoner Angiostrongylose des Hundes festgestellt und die Nacktschneckenart Arion rufus als natürlicher Zwischenwirt ermittelt. Neue experimentelle Zwischenwirte sind die Landschneckenarten Deroceras agreste, D. laeve und Vitrea diaphana sowie die Süßwasserschneckenarten Anisus leucostomus und Lymnaea tomentosa. Von verschiedenen Labortierarten ist nur die Nilratte, Arvicanthis niloticus, für A. vasorum empfänglich, in der sich der Parasit bis zur Geschlechtsreife entwickelt. Hunde lassen sich nach den Untersuchungen von Neff (1971) oral, intraduodenal, intraperitoneal, intravenös, subkutan und perkutan durch die skarifizierte Haut infizieren.

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Angiostronglyosis in man and animals

Summary A review is given on the present state of angiostrongylosis research. From the 16 known Angiostrongylus species three are of medical importance: A. cantonensis (Chen, 1935), Dougherty, 1946, a parasite of rats, may produce meningoencephalitis of man in the Pacific area and South-East Asia. A second species A. costaricensis Morera and Céspedes, 1971 was recently reported from house rats and cotton rats in Costa Rica; it can parasitize the mesenteric blood vessels of man leading to thrombosis and enteritis.According to our present knowledge, the possibility of a pathogenic effect by the parasite of carnivores A. vasorum (Baillet, 1866) to humans may not be fully dismissed. However, the parasite has no cerebral migration in its normal hosts and it is unlikely that it would produce a disease of the central nervous system in man.The authors discuss their partly unpublished data on A. vasorum. The occurrence of autochthonous angiostrongylosis was established in Switzerland transmitted by the slug Arion rufus. The slugs, Deroceras agreste and D. laeve, the terrestrial snail Vitrea diaphana and freshwater snails, Anisus leucostomus and Lymnaea tomentosa were found to be suitable as new experimental intermediate hosts. From many laboratory animals only the Nilerat, Arvicanthis niloticus, was found to be susceptible to the parasite reaching sexual maturity in that host. Experiments carried out by Neff (1971) showed that dogs can be successfully infected per os, through intraduodenal, intraperitoneal, intravenous and subcutaneous injections, or through the percutaneous route by application of infective larvae to the scarified skin.

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Nach einem Vortrag an der VI. Tagung der Dtsch. Ges. für Parasitologie, am 10.–12.4. 1972 in Hannover.     

Cryopreservation and long-term in vitro maintenance of second-stage larvae of Toxocara canis

Second stage larvae of Toxocara canis were isolated from developed eggs, frozen in Eagle's Minimal Essential Medium with 5% dimethyl sulfoxide or 10% glycerol as cryoprotectants according to two cooling schedules and maintained in liquid nitrogen for 1 week. After thawing, the previously frozen larvae (FL) and unfrozen controls (CL) were maintained in a chemically defined medium in vitro for 35 weeks. While CL had motility rates around 95% to 97% throughout the experiment, previously frozen larvae (FL) exhibited rates of 48%–58% at the beginning and of 19%–39% at the end of the 35 week in vitro maintenance period. The surviving FL and CL larvae proved to be infective for mice. Excretory/secretory (ES) antigens isolated from several batches of culture medium in which FL and CL had been maintained reacted in the ELISA with human sera containing antibodies against Toxocara. Antigens from FL and CL separated by SDS-PAGE and silver-stained showed some differences in polypeptide patterns. Western-blot analysis revealed that these differences were not related to antigenic polypeptides but were most likely caused by substances without antigenic properties originating from dead and/or degenerating larvae. It can be concluded that ES antigens produced by previously frozen larvae are essentially the same as those derived from unfrozen controls.The value of cryopreservation of T. canis larvae for routine production of ES antigens will be further evaluated.     

Micronuclei containing whole chromosomes harbouring the selectable gene do not lead to mutagenesis

Loss of heterozygosity is one genetic change observed in manytumours. We do not know whether the loss of chromosomal materialthrough micronucleus formation is a viable mechanism associatedwith, and possibly leading to, genetic disease. Previously,we treated L5178Y mouse lymphoma cells with four aneugens. Althoughthese aneugens induced micronuclei containing predominantlywhole chromosomes, they did not induce mutations at Tk1, theselectable gene, under the same non-toxic conditions in whichthey induced micronuclei. This suggested that the inductionof micronuclei containing whole chromosomes was not an earlyevent leading to phenotypically expressed mutations in thesecells under the conditions used. However, it is possible thatchromosome 11, on which Tk1 resides, may be under-representedin the micronucleus population. To find out the frequency ofinduction of micronuclei containing chromosome 11, we appliedfluorescence in situ hybridization using a chromosome 11 paintto micronuclei induced by colcemid and vinblastine. We foundthat the numbers of micronuclei containing chromosome 11 aremore than sufficient to be detectable as mutations if thesemicronuclei lead to viable mutants. We conclude that the formationof micronuclei containing whole chromosomes does not lead toviable, dividing mutants in this system. ⁵To whom correspondence should be addressed     

Humoral and cellular immune reactions 'in vitro' against allogeneic and autologous human melanoma cells.

Based on 51Cr release from an allogeneic human melanoma cell (M1) cell-mediated (CMC) and antibody-dependent cellular cytotoxicity (ADCC) were determined in twenty-eight melanoma patients, thirty-one healthy controls, ten patients with other tumours and eleven chronic lymphocytic leukaemia (CLL) patients. The results were related to simultaneously performed microcytotoxicity (MC) tests, HL-A typing, plasma membrane fluorescence and B:T cell ratios in the peripheral blood. Furthermore, lymphocytes from six melanoma patients were tested in CMC and ADCC assays against autologous tumour cells. The following results were obtained. (1) A large number of healthy controls possessed lymphocytes which readily lysed M1 target cells in CMC and MC assays. (2) CMC activity of lymphocytes from melanoma patients was generally lower than that of control lymphocytes and decreased further with progression of the disease. (3) CLL lymphocytes were virtually non-toxic for M1 cells, even at high aggressor:target cell ratios. (4) ADCC assays with a heterologous rabbit-anti-M1 serum showed generally higher isotope release than CMC assays; this was particularly pronounced in the melanoma group and in the group of patients with other tumours. (5) No tumour-specific blocking factor could be detected in melanoma sera, as judged by the capacity of the sera to block CMC activity. (6) No obvious correlation was found between the results obtained in short-term CMC and long-term MC assays. (7) T lymphocytes, as determined by E-rosette formation, were significantly diminished in melanoma patients. (8) The HL-A type of lymphocytes from normal donors and melanoma patients did not appear to be related to high or low activity in CMC and MC assays. (9) Preliminary results of 51Cr release tests with autologous melanoma cells were encouraging with respect to the correlation of the results to the clinical course of the disease.     

Symptomatic peripheral arterial disease: the value of a validated questionnaire and a clinical decision rule

BACKGROUND: If a validated questionnaire, when applied to patients reporting with symptoms of intermittent claudication, could adequately discriminate between those with and without peripheral arterial disease, GPs could avoid the diagnostic measurement of the ankle brachial index. AIM: To investigate the Edinburgh Claudication Questionnaire (ECQ) in general practice and to develop a clinical decision rule based on risk factors to enable GPs to easily assess the likelihood of peripheral arterial disease. DESIGN OF STUDY: An observational study. SETTING: General practice in The Netherlands. METHOD: This observational study included patients of > or =55 years visiting their GP for symptoms suggestive of intermittent claudication or with one risk factor. The ECQ and the ankle brachial index were performed. The prevalence of peripheral arterial disease, defined as an ankle brachial index <0.9, was related to risk factors using logistic regression analyses, on which a clinical decision rule was developed and related to the presence of peripheral arterial disease. RESULTS: Of the 4790 included patients visiting their GP with symptoms suggestive of intermittent claudication, 4527 were eligible for analyses. The prevalence of peripheral arterial disease in this group was 48.3%. The sensitivity of the ECQ was only 56.2%. The prevalence of peripheral arterial disease in a clinical decision rule that included age, male sex, smoking, hypertension, hypercholesterolemia, and a positive ECQ, increased from 14% in the lowest to 76% in the highest category. CONCLUSION: This study indicates that the ECQ alone has an inadequate diagnostic value in detecting patients with peripheral arterial disease. The ankle brachial index should be performed to diagnose peripheral arterial disease in patients with complaints suggestive of intermittent claudication, although our clinical decision rule could help to differentiate between extremely high and lower prevalence of peripheral arterial disease.     

Evaluation of cellular substrates for antinuclear antibody determinations.

The immunofluorescent technique was employed to evaluate the sensitivity of 10 human and animal cell monolayers and tissue sections as substrates for titering the antinuclear antibody content of serum samples. The highest mean ranks of sensitivity, the relative ability of each substrate to maintain its sensitivity rank when 21 selected positive sera were tested, were achieved by two fibroblast cell lines, baby hamster kidney (BHK 21/C13) and human lung (WI-38), respectively. The least sensitive substrates were commercial rat kidney and liver tissue sections.     

Evaluation of a medical interviewing course. Use of the helping relationship inventory

Changes in beginning medical students' preferred interview responses appear attributable to a course that emphasizes communication techniques for developing patient rapport. For each of five successive classes, pre/postcourse preferences were obtained for alternative response modes (categorized as understanding, probing, interpretive, supportive, and evaluative. Analysis indicated significant increases in students' preferences for understanding responses and decreases in preferences for evaluative responses (p less than .001). Changes are in the desired direction with respect to course goals, since rapport is generally enhanced by conveying understanding and refraining from premature evaluation. Effects on response preferences of some instructor characteristics are analyzed. Implications for health professions education and research are discussed.