No Detection of Interferon-γ Activity During Early Pregnancy in the Mouse

PROBLEM: Interferons (IFN) have been shown to be secreted by the trophectoderm of implanting embryos in different species, in particular ungulates. In the pig, a clear-cut IFN-γ production, the role of which is unknown, was found in the trophoblast at implantation. A murine counterpart to these IFNs has not yet been identified. METHOD: Two sets of experiments were conducted to test the presence of IFN-γ in the mouse conceptus. First, day 4 blastocysts were collected from Swiss mice and their antiviral activity measured in a microassay using mouse L 929 cells and vesicular stomatitis virus (VSV) in the presence or absence of anti-IFN-γ antibodies. In a second set of experiments, uteri from Swiss mice on days 5.5 and 6.5 of pregnancy were flushed and the resulting fluids assayed in a specific and sensitive ELISA test. RESULTS: In the antiviral assay, no consistent IFN-like activity was found. The viral challenge also revealed a high susceptibility of mouse blastocysts to VSV infection. By ELISA, all but two samples (N = 75), whether on 5.5 or 6.5, were found negative. CONCLUSION: We conclude that in this rodent species IFN-γ is most probably not involved in early maternal-fetal interactions.     

Biochemical and immunological properties of ribonucleic acid-rich extracts from Francisella tularensis.

Ribonucleic acid (RNA)-rich extracts derived from the attenuated strain of Francisella tularensis (strain LVS) protected Swiss mice against lethal challenge with F. tularensis strain 425 but not against strain SCHU S4. No killed preparation, including an RNA-rich extract from SCHU S4 itself, offered protection against strain SCHU S4 in contrast to the high level of protection offered against this strain by vaccination with live strain LVS. The protective activity observed against strain 425 was sensitive to ribonuclease but not to Pronase. Protective activity is not a general property of bacterial RNA, since RNA-rich extracts from Staphylococcus aureus offered no protection against tularemia, although disc gel electrophoresis showed similar kinds and amounts of RNA in preparations form F. tularensis and S. aureus. Furthermore, inability to localize activity to a specific region in sucrose gradients suggests a structural rather than an informational role for the RNA in such extracts. RNA-rich extracts from F. tularensis but not from S. aureus were efficient inducers of F. tularensis opsonins in mouse serum, suggesting one mechanism by which such extracts confer protection.     

Hereditary cardiomyopathy in W/SSM rats: Biochemical mechanisms of development

One mechanism shown to be responsible for the occurrence of hypertrophic cardiomyopathy in rats of the W/SSM strain, in which this disease is genetically determined, is impairment of cellular membrane integrity resulting from increased hexose transport to cells, generation of hydroxyl radicals, and intensified lipid peroxidation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 151–154, August, 1995     

Toxicity and immunogenicity of Neisseria meningitidis lipopolysaccharide incorporated into liposomes.

To obtain nontoxic and highly immunogenic lipopolysaccharide (LPS) for immunization, we incorporated Neisseria meningitidis LPS into liposomes. Native LPS and its salts were incorporated by the method of dehydration-rehydration of vesicles or prolonged cosonication. The most complete incorporation of LPS into liposomes and a decrease in toxicity were achieved by the method of dehydration-rehydration of vesicles. Three forms of LPS (H+ form, Mg2+ salt, and triethanolamine salt) showed different solubilities in water, the acidic form of LPS, with the most pronounced hydrophobic properties, being capable of practically complete association with liposomal membranes. An evaluation of the activity of liposomal LPS in vitro (by the Limulus amoebocyte test) and in vivo (by monitoring the pyrogenic reaction in rabbits) revealed a decrease in endotoxin activity of up to 1,000-fold. In addition, the pyrogenic activity of liposomal LPS was comparable to that of a meningococcal polysaccharide vaccine. Liposomes had a pronounced adjuvant effect on the immune response to LPS. Thus, the level of anti-LPS plaque-forming cells in the spleens of mice immunized with liposomal LPS was 1 order of magnitude higher and could be observed for a longer time (until day 21, i.e., the term of observation) than in mice immunized with free LPS. The same regularity was revealed in a study done with an enzyme-linked immunosorbent assay. This study also established that antibodies induced by immunization belonged to the immunoglobulin M and G classes, which are capable of prolonged circulation. Moreover, liposomal LPS induced a pronounced immune response in CBA/N mice (defective in B lymphocytes of the LyB-5+ subpopulation). The latter results indicate that the immunogenic action of liposomal LPS occurs at an early age.     

Effect of oxymethacil on the microcirculation and cerebral cortical single unit activity in cats with acute phosphacol poisoning

S. M. Kirov Military Medical Academy, I. P. Pavlov Institute of Physiology, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR S. N. Golikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 8, pp. 115–117, August, 1991.     

Germline mutations of the MEN1 gene in familial multiple endocrine neoplasia type 1 and related states

Familial multiple endocrine neoplasia type 1 (FMEN1) is an autosomal dominant trait characterized by tumors of the parathyroids, gastro- intestinal endocrine tissue, anterior pituitary and other tissues. We recently cloned the MEN1 gene and confirmed its identity by finding mutations in FMEN1. We have now extended our mutation analysis to 34 more unrelated FMEN1 probands and to two related states, sporadic MEN1 and familial hyperparathyroidism. There was a high prevalence of heterozygous germline MEN1 mutations in sporadic MEN1 (8/11 cases) and in FMEN1 (47/50 probands). One case of sporadic MEN1 was proven to be a new MEN1 mutation. Eight different mutations were observed more than once in FMEN1. Forty different mutations (32 FMEN1 and eight sporadic MEN1) were distributed across the MEN1 gene. Most predicted loss of function of the encoded menin protein, supporting the prediction that MEN1 is a tumor suppressor gene. No MEN1 germline mutation was found in five probands with familial hyperparathyroidism, suggesting that familial hyperparathyroidism often is caused by mutation in another gene or gene(s).      

Immunolocalization of inhibin and activin subunits in human endometrium across the menstrual cycle

Inhibin/activin alphaC/alphaN and betaA subunits were localized immunohistochemically in the human endometrium throughout the menstrual cycle using an affinity-purified sheep polyclonal antibody raised against the alphaC/alphaN subunit and an affinity-purified rabbit polyclonal antibody raised against the betaA subunit. The betaB subunit was below the level of detection in all human endometrial samples tested. Immunoreactive inhibin alphaC/alphaN subunit was localized in the luminal epithelium, glandular epithelium, stromal tissues and vascular endothelium with no significant variation across the normal menstrual cycle. Immunoreactive betaA subunit, common to inhibin A and activins AA and AB was localized in the luminal and glandular epithelium and in migratory cells while the endometrial stromal cells, decidua, vascular smooth muscle and endothelium were devoid of immunoreactivity. A significant variation of immunoreactive betaA subunit was observed in glandular and luminal epithelium across the normal menstrual cycle. In proliferative endometrium, only a very low level of betaA immunostaining was seen in luminal and glandular epithelium, while the luminal epithelial staining increased significantly in the early secretory phase and remained relatively constant over the rest of the menstrual cycle. A progressive increase in betaA immunoreactivity was observed also in the glandular epithelium during the secretory phase reaching a maximum in the late secretory phases, and decreasing at menstruation. Co-localization studies on serial sections suggested that the migratory cells expressing strong betaA immunoreactivity were macrophages and neutrophils but not eosinophils or mast cells. Thus, cells within the human endometrium are capable of expressing inhibin/activin molecules in vivo. The variation in the pattern of secretion of the betaA subunit across the menstrual cycle suggests that activin peptides may have a physiological role in endometrial function.      

磺胺嘧啶银均匀微晶胶原蛋白烧伤膜的制备及其质量控制

目的制备磺胺嘧啶银均匀微晶胶原蛋白烧伤膜,测定磺胺嘧啶银均匀微晶胶原蛋白烧伤膜的含量。方法应用交 联剂法制备磺胺嘧啶银均匀微晶胶原蛋白烧伤膜,用分光光度法测定磺胺嘧啶银均匀微晶胶原蛋白烧伤膜含量。结果 该法得到乳白色半透明、光滑、具有弹性的凝胶膜状物,检测线性范围为４．１～１４．２ ｍｇ／Ｌ,ｒ＝０．９９９９,磺胺嘧啶银方法回收 率为（１００．３０±０．０１）％、磺胺嘧啶银均匀微晶方法回收率为（１００．４４±０．０９）％;日内ＲＳＤ为（１．１３±０．６３）％、日间ＲＳＤ为 （１．６３±０．３３）％。结论用交联剂法制备胶原蛋白模具有简便,便于铸型,成膜性好等优点,可用于ＳＤ－Ａｇ胶原蛋白烧伤 膜的质量控制。     

剖宫产率的变迁与产后出血的关系

目的：探讨剖宫产率的上升对产后出血的影响。方法：对1995年1月－1998年12月在我院分娩的6308例产妇进行回顾性分析。统计分析剖宫产率的变迁和产后出血的关系,以及不同分娩方式对产后出血的影响,分析造成产后出血的原因。结果：剖宫产率和产后出血率均呈逐年上升的趋势,在不同分娩方式中,产后出血的产生率以剖宫产组最高。结论：严格掌握剖宫产指征,降低选择性剖宫产是减少产后出血发生的一项重要措施。