Gonadectomy and growth ofTaenia crassiceps (Cestoda) cysticerci in mice

Summary Gonadectomy of SWR of both sexes significantly reduced the number of cysticerci ofTaenia crassiceps, 60 days post infection. There was a significant decrease in the total number of larvae and the number of nonbudding individuals, corresponding with increased number of budding larvae. This indicates that the asexual multiplication of cysticerci in populations from gonadectomized mice was inhibited.     

Environmental temperature and the growth ofTaenia crassiceps cysticerci in mice

Summary Mice kept at low (5±1 °C) and high (35±1 °C) temperature harboured significantly lessTaenia crassiceps cysticerci than controls kept at 21±1 °C. This effect was more pronounced in heat-stressed than in cold-stressed animals and more in males than in females.     

Gonadectomy and survival ofAncylostoma caninum (Nematoda) filariform larvae in mice

Summary Gonadectomy reversed the susceptibility response of male and female Swiss mice toAncylostoma caninum infection. Orchiectomy decreased the survival of filariform larvae (p>0.001 to <0.25), whereas ovariectomy increased it significantly (p>0.001 to <0.01).We wish to acknowledge our gratitude to the late Professor H. Swarup for valuable suggestions, to Professor G.N. Johri for laboratory facilities, and to the University Grants Commission, New Delhi, for financial support in the form of a Junior Research Fellowship to I. B.     

Multiplication of human-derived Pneumocystis carinii in severe combined immunodeficient (SCID) mice.

Clinically healthy SCID mice were infected intratracheally with Pneumocystis carinii (PC) of human origin. The data obtained provides unambiguous evidence that progressive multiplication of PC organisms of human origin takes place in the lungs of experimentally infected animals. SCID mice that were infected with human-derived PC also revealed a markedly greater number of mouse PC organisms in their lungs than the controls. All the SCID recipients of human PC died by day 65 post infection, whereas the controls, housed under identical conditions, started dying significantly later due to severe mouse pneumocystosis. This animal model could be used for the maintenance and propagation of human PC, and for evaluating strategies for treating human pneumocystosis.     

Proopiomelanocortin expression in the skin during induced hair growth in mice.

We demonstrate for the first time a hair cycle-dependent gene and protein expression of proopiomelanocortin in mouse skin in vivo. Northern blot detected POMC mRNA with an apparent size of 0.9 kb in anagen but not telogen skin. Western blot emphasized a specific protein of 30-33 kDa recognized by anti beta-endorphin in late but not early anagen or telogen skin. By immunocytochemistry, beta-endorphin antigen was localized in the sebaceous gland in a hair cycle dependent manner.     

Factor(s) from nonmacrophage bone marrow stromal cells inhibit Lewis lung carcinoma and B16 melanoma growth in mice

Bone marrow stroma produces positive and negative growth regulators which constitute the hematopoietic microenvironment. As many tumors metastasize to the bones, these regulators may also influence tumor growth. Hematopoietic cytokines may indeed exert both positive and negative effect on tumor growth. We report that, when mixed with tumor cells. adherent bone marrow cells inhibit primary tumor growth and metastases formation in mice transplanted with Lewis lung carcinoma or B16 melanoma. Peritoneal macrophages or lymph node cells did not exert any influence. The tumor inhibition was apparently due to soluble factor(s) released by marrow stromal cells. In cocultures with B16 melanoma cells, adherent bone marrow cells exerted a significant antiproliferative effect which was increased by previous culture of the bone marrow cells with granulocyte-macrophage colony-stimulating factor but not with macrophage colony-stimulating factor. Neither neutralizing antibodies against tumor necrosis factor-alpha, transforming growth factor-beta or interferon alpha/beta nor addition of Escherichia coli lipopolysaccharide to generate inflammatory cytokines could affect the antiproliferative effect of bone marrow stromal cells. The bone marrow stroma factor(s) which inhibit tumor growth might, therefore, be a novel growth regulator.     

Chromosome change during growth inPuschkinia libanotica L. (Liliaceae)

Summary The variation in chromosome size in root-tip meristem ofPuschkinia libanotica L. was studied at different days of root growth with special attention to DNA, RNA, total protein and histone contents. The results show that the size and organisation of chromosomes even within the one tissue is subject to considerable change during growth and development.The author is thankful to Prof. H. Rees, FRS, Department of Agricultural Botany, University College of Wales, Aberystwyth, Wales, U.K., for his guidance and to University College of Wales, Aberystwyth, for granting him a SRC fellowship.     

The umbrellar growth process in the leptomedusaePhialidium hemisphaericum (Syn.Campanularia johnstoni)

Zusammenfassung Das Wachstum der umbrellaren Gewebe bei der HydromedusePhialidium hemisphaericum wurde durch lokale Anfärbung mit dem Vitalfarbstoff Bismarckbraun untersucht. Die Wachstumsregion, welche ex- und subumbrellare Gewebe bildet, liegt am Rande der Medusenglocke in der Nähe des Ringkanales. Gewebewanderungen konnten keine festgestellt werden. Die möglichen Folgen der unterschiedlichen Wachstumsvorgänge bei Polyp und Meduse werden diskutiert.

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These investigations were supported by the «Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung» No. 3.205.69.     

Mast cells in the pinna of Balb/c 'nude' (nu/nu) and heterozygotes (ny/+)mice.

The relative number of mast cells in the ear lobes' skin (pinna) of nude (athymic) nu/nu and normal (thymic) nu/+ heterozygotes of Balb/c mice was similar. The results obtained contradict some suggestions about the general influence of the thymus on the number of mast cells in the skin and suggest the existence of some local factor(s) in regulation of skin mast cell numbers.     

Induction of alloxan diabetes in obese-hyperglycemic mice (genotype obob)

Zusammenfassung Nachweis, dass fettsüchtige, hyperglykämische Mäuse nach Alloxan-Injektion einen erhöhten Blutzuckerspiegel und herabgesetzte Insulinkonzentrationen im Vergleich mit den unbehandelten Kontrolltieren zeigen. B-Zellen der Langerhansschen Inseln zeigen nach Alloxan nekrotische Veränderungen.

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This work was supported by the Swedish Medical Research Council, the Swedish Diabetes Association and the Nordic Insulin Foundation.     

Vascular endothelial growth factors (VEGFs) and stroke

Vascular endothelial growth factors (VEGFs) have been shown to participate in atherosclerosis, arteriogenesis, cerebral edema, neuroprotection, neurogenesis, angiogenesis, postischemic brain and vessel repair, and the effects of transplanted stem cells in experimental stroke. Most of these actions involve VEGF-A and the VEGFR-2 receptor, but VEGF-B, placental growth factor, and VEGFR-1 have been implicated in some cases as well. VEGF signaling pathways represent important potential targets for the acute and chronic treatment of stroke.     

Macrophage activation in mice lacking thymus-derived (T) cells

Zusammenfassung Ein gewisser Grad von Makrophagenaktivierung, gemessen an der Fähigkeit der Listerien-Elimination, wird auch in adult thymektomierten, mit Knochenmark rekonstituierten Mäusen sowie in nude/ nude-Mäusen beobachtet und daraus der Schluss gezogen, dass die Makrophagenaktivierung nicht unter allen Umständen mit der Anwesenheit von T-Lymphozyten verknüpft sein muss.     

Activity-induced thermogenesis in lean and genetically obese (ob/ob) mice

Summary Motor activity was approximately 60% lower in genetically obese than in lean mice, during three consecutive hours at thermal neutrality. It is suggested that this must have contributed to the lower heat production measured in the obese mice and that activity-induced thermogenesis contributes significantly to differences in energy expenditure between the genotypes, at least in the short-term.     

Activity-induced thermogenesis in lean and genetically obese (ob/ob) mice

Motor activity was approximately 60% lower in genetically obese than in lean mice, during three consecutive hours at thermal neutrality. It is suggested that this must have contributed to the lower heat production measured in the obese mice and that activity-induced thermogenesis contributes significantly to differences in energy expenditure between the genotypes, at least in the short-term.     

Reduced collagen biosynthesis in oral mucosa of beige (Chediak-Higashi) mice

Summary Oral mucosa of beige (Chediak-Higashi) mice had decreased levels of collagen synthesis and prolyl hydroxylase activity compared with normal animals. No significant difference was observed in non-collagen protein synthesis between the two groups. These results suggest that decreased collagen biosynthesis in oral tissues may be partially involved in the increased incidence of periodontal disease in the Chediak-Higashi syndrome.     

Reduced collagen biosynthesis in oral mucosa of beige (Chediak-Higashi) mice

Oral mucosa of beige (Chediak-Higashi) mice had decreased levels of collagen synthesis and prolyl hydroxylase activity compared with normal animals. No significant difference was observed in non-collagen protein synthesis between the two groups. These results suggest that decreased collagen biosynthesis in oral tissues may be partially involved in the increased incidence of periodontal disease in the Chediak-Higashi syndrome.     

Multiplication of human-derivedPneumocystis carinii in severe combined immunodeficient (SCID) mice

clinically healthy SCID mice were infected intratracheally withPneumocystis carinii (PC) of human origin. The data obtained provides unambiguous evidence that progressive multiplication of PC organisms of human origin takes place in the lungs of experimentally infected animals. SCID mice that were infected with human-derived PC also revealed a markedly greater number of mouse PC organisms in their lungs than the controls. All the SCID recipients of human PC died by day 65 post infection, whereas the controls, housed under identical conditions, started dying significantly later due to severe mouse pneumocystosis. This animal model could be used for the maintenance and propagation of human PC, and for evaluating strategies for treating human pneumocystosis.     

EG-VEGF controls placental growth and survival in normal and pathological pregnancies: case of fetal growth restriction (FGR)

Identifiable causes of fetal growth restriction (FGR) account for 30 % of cases, but the remainders are idiopathic and are frequently associated with placental dysfunction. We have shown that the angiogenic factor endocrine gland-derived VEGF (EG-VEGF) and its receptors, prokineticin receptor 1 (PROKR1) and 2, (1) are abundantly expressed in human placenta, (2) are up-regulated by hypoxia, (3) control trophoblast invasion, and that EG-VEGF circulating levels are the highest during the first trimester of pregnancy, the period of important placental growth. These findings suggest that EG-VEGF/PROKR1 and 2 might be involved in normal and FGR placental development. To test this hypothesis, we used placental explants, primary trophoblast cultures, and placental and serum samples collected from FGR and age-matched control women. Our results show that (1) EG-VEGF increases trophoblast proliferation ([³H]-thymidine incorporation and Ki67-staining) via the homeobox-gene, HLX (2) the proliferative effect involves PROKR1 but not PROKR2, (3) EG-VEGF does not affect syncytium formation (measurement of syncytin 1 and 2 and β hCG production) (4) EG-VEGF increases the vascularization of the placental villi and insures their survival, (5) EG-VEGF, PROKR1, and PROKR2 mRNA and protein levels are significantly elevated in FGR placentas, and (6) EG-VEGF circulating levels are significantly higher in FGR patients. Altogether, our results identify EG-VEGF as a new placental growth factor acting during the first trimester of pregnancy, established its mechanism of action, and provide evidence for its deregulation in FGR. We propose that EG-VEGF/PROKR1 and 2 increases occur in FGR as a compensatory mechanism to insure proper pregnancy progress.     

Effect of synthetic polynucleotides on the growth of transplantable tumours in BALB/c mice.

The effect of BALB/c mice pretreatment with tumour cells (a mammary adenocarcinoma, ADK-1t and an IgA secreting plasmocytoma, MOPC-315) adsorbed with poly I:C, poly I and poly C is examined. Only mice pretreated with cells of both tumours adsorbed with poly I:C and poly C proved to be extensively protected against challenge by homologous untreated tumour cells, whereas this was not so in the case of poly I. A possible explanation of this phenomenon is discussed.