Production and characterization of antibody against fusarochromanone

Antibody against fusarochromanone (TDP‐1) was obtained from rabbits after immunization with TDP‐1 conjugated to bovine serum albumin (BSA). An indirect enzyme‐linked immunosorbent assay (ELISA) using TDP‐1‐ovalbumin conjugate as the antigen coated on to the microtiter plate was used for monitoring the antibody liter. For toxin detection, a direct competitive ELISA in which TDP‐1 was conjugated to horseradish peroxidase (HRP) was used. Competitive direct ELISA revealed that the antibody had about 5.6 and 4.5 times greater binding efficiency for monoacetyl fusarochromanone (TDP‐2) and diacetylated TDP‐1 than TDP‐1. The concentration causing 50% inhibition of binding of TDP‐1‐HRP to the antibody by TDP‐1, TDP‐2 and diacetyl‐TDP‐1 were 2.8, 0.5 and 0.62 ng/ml, respectively. For the analysis of fusarochromanones in wheat and barley, the toxins were first extracted from the commodities with 100% methanol. A small aliquot of the extract was dried, acetylated, diluted in buffer and then analyzed directly by ELISA. The overall recovery for fusarochromanone in the wheat and barley samples spiked with TDP‐1 in the concentration range of 20 to 500 ppb were found to be 97% and 103.4% with cv of 15% and 11.2% for barley and wheat, respectively.     

Comparison of hen egg lysozyme immunoassays based on different labels

To check the concentrations of hen egg lysozyme in foodstuffs, added as a bacteriostatic agent, immunoassays based on different labels have been developed. The following detection limits (defined as non‐specific binding increased by three standard deviations) were achieved using antibody labelled with either peroxidase ¹²⁵ I or a biotin‐streptavidin system: 0–8; 0–75 and 0–13 ng/ml, respectively. Only the most sensitive lysozyme immunoassay was likely to be suitable for application to analysis of cheese because matrix interference effects mean that sample extracts need to be diluted prior to assay.     

Ruthenium red affects the contractile apparatus but not sarcoplasmic reticulum Ca2+ release of skinned papillary muscle

Ruthenium red has been shown to have a positive inotropic effect on isolated perfused hearts. The cellular mechanism of this action is not clear. Ruthenium red is able to block the Ca²⁺ release channel in isolated sarcoplasmic reticulum (SR) vesicle and reconstituted channel preparations. However, the effect of ruthenium red on SR Ca²⁺ release has not been studied in skinned cardiac muscle preparations. In the present study we investigated the actions of ruthenium red on both the characteristics of force generation by the contractile apparatus and Ca²⁺ release from the SR in chemically skinned rat papillary muscle. Ruthenium red (2 and 10 M) significantly increased the Ca²⁺ sensitivity of the contractile apparatus (decreasing Ca²⁺ required for the half-maximal response from 1.56±0.04 M to 1.46±0.05 M) but had no effect on the maximal Ca²⁺-activated force in triton X-100 treated fibers. This result may suggest one explanation for the positive inotropic effect of ruthenium red on the heart. On the other hand, ruthenium red had no significant effect on either caffeine-induced Ca²⁺ release or Ca²⁺-induced Ca²⁺ release from the SR in saponin-skinned muscle fibers. Lack of a blocking effect on SR Ca²⁺ release by ruthenium red in skinned fibers suggests that the SR Ca²⁺ channels in intact preparations have characteristics that are different from those of either vesicular or reconstituted channel preparations.     

Morphological changes in the internal organs in chronic streptococcal infection

A histological and histochemical study was made of the internal organs of albino mice at various times (from 24 h to 27 weeks) after a single intraperitoneal injection of L-forms of -hemolytic group A streptococci. A progressive pathological process (myocarditis, hepatitis, glomerulonephritis) against a marked allergic bacground and leading to systemic lesions of the tissues was discovered.Institute of Human Morphology, Academy of Medical Sciences of the USSR. N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byullten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 9, pp. 111–115, September, 1975.     

Lactoferrin gene expression is estrogen responsive in human and rhesus monkey endometrium.

We have previously shown that the estrogen responsiveness of the human lactoferrin gene in a transient transfection system is mediated through an imperfect estrogen response element (ERE) and a steroidogenic factor 1 binding element (SFRE) 26 bp upstream from ERE. Reporter constructs containing SFRE and ERE respond to estrogen stimulation in a dose-dependent manner, whereas mutations at either one of the response elements severely impaired the estrogen responsiveness. In this study, we demonstrated that estrogen receptor (ERalpha) binds to the human lactoferrin gene ERE and forms two complexes in an electrophoresis mobility shift assay (EMSA). These complexes could be supershifted by an antibody to ERalpha. We also showed that in normal cycling women, lactoferrin gene expression in the endometrium increases during the proliferative phase and diminishes during the luteal phase. This in-vivo study thus supported the finding from transient transfection experiments that the human lactoferrin gene expression is elevated in an environment with a high level of estrogen. The estrogen effect on lactoferrin gene expression in the rhesus monkey endometrium was studied by Western blotting and immunohistochemistry. The immunohistochemistry results showed that immunoreactive lactoferrin protein was not detectable in the untreated ovariectomized monkey endometrium, was elevated by estrogen treatment, and was suppressed by sequential, combined estrogen plus progesterone treatment. In conclusion, this study has shown that lactoferrin gene expression is responsive to estrogen in primate endometrium.     

An autopsy-proved case of AIDS in Taiwan

The first case of AIDS positively identified in a non-foreigner in Taiwan was a 25-year-old unmarried male who had practiced homosexuality for ten years. The patient began to have abdominal pain accompanied with loose stools and weight loss in June 1985, followed by fever, cough, headache, dizziness, and loss of memory. Facial hyperpigmentation and extensive oroesophageal candidiasis were noted. Laboratory studies showed severe lymphopenia with a reversed T-helper to T-suppressor ratio, cutaneous anergy and polyclonal gammopathy. Human immunodeficiency virus (HIV) antibodies were positive by ELISA and Western blot, and the virus was isolated from the blood. At autopsy, disseminated cytomegalovirus infection, extensive CNS toxoplasmosis and early lesions of Kaposi's sarcoma were demonstrated. The detection of HIV in the adrenal medulla supports the consensus that the virus is neurotropic.     

氧分压在体监测仪的研制

作者报道一种稳定性较高的氧分压在体监测，为医学研究、临床诊断提供一种新的可靠的测试方法及设备，具有较大的应用价值。     

Immunodepressive action of cyclophosphamide on different strains of mice

The immunodepressive effect of cyclophosphamide (CP) was studied on mice of three strains (BALB/c, CBA, DBA/2) immunized with sheep's red cells (RBC). When the optimal immunizing dose of antigen was used (5×10⁸ RBC) the strongest immunodepression was observed in the DBA/2 mice, but when a large dose of RBC was used (6.2×10⁹) the strongest effect was observed in DBA/2 and CBA mice. The action of CP was shown to depend on the dose of antigen injected: In BALB/c mice the decrease in the number of antibody-forming cells was the same with both doses of RBC, in the DBA/2 mice an increase in the dose of antigen led to weakening of immunodepression, but in CBA mice immunodepression was intensified (provided that sufficiently large doses of CP were used). Determination of the rate of oxidative hydroxylation of CP by the mouse liver microsomes showed it to be comparatively low in DBA/2 and CBA mice and much higher in BALB/c mice. It is suggested that the differences in the immunodepressive action of CP thus revealed could be due to differences in the sensitivity of the target cells and (or) differences in its metabolism in mice of different strains.Laboratory of Immunogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR, N. N. Zhakov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 438–440, April, 1977.     

Production of a strain of human osteogenic sarcoma cell line HOS transplantable into nude mice and rats

All-Union Oncologic Scientific Center, Academy of Medical Sciences of the USSR. Institute of Virology, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 106, No. 10, pp. 471–472, October, 1988.