Substance P-induced inhibition of Leydig cell steroidogenesis in primary culture

The effect of substance P (SP) on hamster Leydig cell steroidogenesis in primary culture was investigated. Purified Leydig cells were cultured with or without SP for 24 h. The levels of testosterone and progesterone in the culture media were 174 +/- 20 pg ml-1 and 105 +/- 12 pg ml-1, respectively. In the presence of SP (10(-7) mol l-1), testosterone concentration significantly decreased to 123 +/- 19 pg ml-1, e.g. with 29.3%. By contrast, at the concentration used, SP had no effect on progesterone secretion. The possible molecular mechanism of the SP action on Leydig cell function was discussed. The reported results indicate that SP can modulate Leydig cell steroidogenesis in culture.     

Interaction of carboxypeptidase A with monoclonal antibodies

Several mouse monoclonal antibodies to carboxypeptidase A (CPA) were prepared and purified, and their interaction with the enzyme was investigated. CPA is a well-characterized zinc-containing exopeptidase exhibiting peptidase as well as esterase activity. The antibodies obtained could be classified as follows: antibodies inhibiting mainly the peptidase activity of the enzyme, antibodies inhibiting mainly its esterase activity, antibodies affecting both activities, and antibodies which bind to the enzyme but have no marked effect on its catalytic properties. Binding constants of approximately 10(6) M-1 were obtained for most of the antibody-enzyme complexes tested. Additional information on the effect of the monoclonal antibodies on the active site of CPA was obtained by determining the change in the circular dichroism spectra of arsanilazotyrosine-248 carboxypeptidase A occurring as a result of the interaction of the enzyme with the antibodies studied. These findings suggest that CPA possesses at least three different specific antigenic sites, and that the active site of the enzyme for its peptidase activity differs from that for its esterase activity, though both sites seem to overlap to a considerable extent.     

Thymus-dependent increase in number of T cells in parathymic lymph nodes induced by the biscoclaurine alkaloid, cepharanthine

In mice treated with cepharanthine (Cepha), a biscoclaurine alkaloid, the number of T cells was increased in the parathymic lymph nodes (PtLNs) which are considered to be the specialized lymph nodes in local differentiation of T cells. Such PtLN cells exhibited augmented proliferative responses to T cell mitogens and exogenous interleukin 2 (IL 2) and showed a great ability to produce IL2, which suggests an increase in mature T cells in the PtLN. However, such increases in the number of T cells and in the mitogen response were not observed in adult thymectomized mice. A low level of plasma prostaglandin E2 (PGE2) was observed in Cepha-treated mice. Replenishment of the PGE2 in such mice with exogenous PGE2 prevented the increase in T cells in the PtLN. These results suggest that the migration of mature T cells from the thymus to PtLN is increased by Cepha and that Cepha is able to regulate their traffic by a prostaglandin-mediated system.     

胃液中肿瘤相关抗原（MG—Ag）IRMA对胃癌的诊断价值

本文报告我院１９９４年１１月～１９９５年１１月应用放射免疫分析法测定了２４６例胃液胃癌抗原。结果显示对胃癌诊断的敏感性为８２％，特异性７０％，胃癌的胃液胃癌抗原测定与非胃癌，癌前病变及良性病变比较，有明显差异，经卡方检验分别为Ｘ＾２＝６２．４４６，Ｐ〈０．０１，Ｘ＾２＝４４．３７５，Ｐ〈０．０１及Ｘ＾２＝７８．０５５，Ｐ〈０．０１，提示胃液胃癌抗原的检测对胃癌诊断有重要价值。     

Immunological cross-reactivity between the collagen-like fragment of human Clq and human type I collagen

In guinea pigs immunized with human acid-soluble type I collagen in the native form immunological cross-reactivity with the collagen-like fragment of human Clq, CLF,4 was observed. At the cellular level, this fragment elicited a clear-cut delayed-type hypersensitivity reaction in 11 out of 20 collagen-immunized guinea pigs as demonstrated in skin tests after injection of 10–100 μg CLF. These 11 animals, and only these, also showed positive skin reactions when challenged with low doses of native collagen (2.0 μg). At the humoral level, only one animal had anticollagen antibodies that cross-reacted with CLF both in passive hemagglutination and solid-phase radioimmunoassay. Depending on the detection method used, only five (seven) animals showing cell-mediated cross-reactivity with CLF were also found to be anticollagen-antibody-positive.     

Effects of spinal lesions on substance P levels in the rat sympathetic preganglionic cell column: evidence for local spinal regulation

Substance P has been localized to the neuropil of sympathetic preganglionic neurons in light and electron microscopic studies. Two recent reports have suggested that the majority of substance P in the rat intermediolateral cell column was contained in synaptic terminals of bulbospinal axons. However, previous investigations in our laboratory indicated the presence of major substance P spinal-sympathetic preganglionic neuron circuitry in pigeon. The present study used radioimmunoassay and immunohistochemistry to examine substance P levels in rat intermediolateral cell column following various spinal lesions in order to assess the relative contributions of bulbospinal and intraspinal substance P neurons to the substance P content of the intermediolateral cell column. The results from these experiments support the existence of both bulbospinal and intraspinal substance P-containing projections to the rat intermediolateral cell column. In addition, characterization of spinal cord substance P-like immunoreactivity by combined high performance liquid chromatography and radioimmunoassay, revealed that substance P in rat intermediolateral cell column was indistinguishable from synthetic substance P. Following transection of thoracic spinal cord, substance P-immunoreactive staining was still evident in the intermediolateral cell column caudal to the lesion. These substance P-positive fibers were studded with bouton-like swellings and appeared normal. Following high cervical hemisection, depletion of substance P (radioimmunoassay measurements) was bilateral and equal in the intermediolateral cell column: 25% depletion was observed after 7 days and 35% depletion after 14 days. However, rats which were hemisected at low cervical and/or mid-thoracic levels contained normal or elevated amounts of substance P in the intermediolateral cell column. Since substance P remains in the intermediolateral cell column following total transection, substance P spinal-sympathetic preganglionic neuron circuitry must exist. Additionally, depletion of substance P following high cervical hemisection suggests the existence of a substance P-containing, bilateral bulbospinal pathway to the intermediolateral cell column. The observation that substance P levels were normal or elevated following low cervical lesions raises the possibility that intraspinal substance P neurons can compensate for loss of substance P in the spinal cord. Sprouting or altered substance P metabolism and/or release by intraspinal substance P neurons could be responsible, suggesting an important homeostatic mechanism for maintaining substance P content within the intermediolateral cell column.     

Comparison of radioimmunoprecipitation assays for the detection of human anti-tumor virus antibodies

The demonstration of human antibodies reactive in radioimmunoprecipitation assays (RIAs) with primate tumor virus (oncornavirus) antigen has implications for a possible viral etiology of certain human tumors. The positive results reported by us contradicted previously published negative findings and led to considerable scientific controversy. We feel much of the discrepancy may be of methodological origin. An attempt is therefore made in this communication to resolve these apparent discrepancies by comparing various published parameters of the RIAs used in the search for human antibodies reactive with oncornavirus antigens.     

Indirect and reverse radioimmunoassays and their apparent specificities in the detection of antibodies to enteroviruses in human sera

Indirect radioimmunoassays (RIAs) of IgM and IgG antibodies to enteroviruses have been developed, using coxsackieviruses B1 and B3, and echoviruses 11 and 30. The titres of IgM and IgG were assayed in paired sera from patients infected with one of these viruses or coxsackieviruses A7, A9, A16, B2, B4, B5 or echoviruses 4, 17, or 25. Both IgM and IgG were found in almost all serum pairs with each of the four viruses used as an antigen, and there were no certain differences between titres obtained with homologous and heterologous antigens. The convalescent phase specimens contained significantly higher titres compared with the acute phase specimens, the difference being most pronounced for IgG. Of the specimens from patients with nonenterovirus infections, a relatively high percentage contained IgM and IgG against enterovirus antigen. However, no increases in titres were seen between acute and convalescent specimens. When specimens from younger patients, aged 2 days to 22 months, without evidence of enterovirus infections, were assayed with enterovirus antigen, the frequency of IgM titres was seen to increase with age. Almost all specimens from newborns were negative, whereas the specimens from 12- to 22-month-old children showed a high frequency of IgM titres. In specimens from patients aged 2 days to 8 months, the ratio between IgM and IgG titres increased with age, probably due to a loss of maternal IgG. The IgG titres in specimens from 8.5- to 22-month-old children were similar to the titres of specimens from the patients with nonenterovirus infections. A reverse IgM assay was also developed, using the same viruses and serum specimens as for the indirect assays. In contrast to the indirect IgM assay, the reverse IgM assay was apparently type specific, provided that the amount of labeled virus was carefully standardized. The reverse IgM RIA detected and identified antibody responses better than the neutralization test. Attempts to develop a reverse IgG assay were promising concerning the specificity, but the sensitivity was low.     

血清PSA RIA在前列腺癌患者手术前后的临床应用价值

目的 :探讨血清前列腺特异性抗原 (PSA)在前列腺癌 (PC)患者手术前后的临床应用价值。方法 :采用放射免疫分析 (RIA)对 35例正常人及 4 8例PC患者在手术前后进行血清PSA测定。结果 :术前检测PC组 4 6例阳性 ,PC与正常组PSA测定值分别为 5 4 4 7± 4 3 5 2ng/ml与 1 72± 1 14ng/ml(p <0 0 0 1) ,对PC检测的灵敏度 95 8% ,特异性 95 %。其中 2 3例患者在确诊PC前患有前列腺增生 (BPH)时血清PSA水平为 6 2 3±2 94ng/ml,在确诊PC时血清PSA水平上升至 5 6 84± 4 8 12ng/ml(p <0 0 0 1)。术后观察PSA在 3～ 6个月降为正常 ,患者均已生存 4年以上 ,一般情况良好 ,术后PSA无明显变化者均在 2年内先后死亡 ,其中 8例为全身骨转移。结论 :血清PSARIA检测对PC术前诊断及术后评估患者的预后具有良好的应用价值     

肿瘤病人舌苔变化与唾液中人上皮生长因子的关系研究

目的 :研究肿瘤病人舌苔变化与唾液中人上皮生长因子h -EGF含量的关系。方法 :采用1 2 5 I放射免疫分析法 (RIA )。结果 :15 2例肿瘤病人唾液中h -EGF含量为 (4.0 70± 1.0 ) μg L ,明显高于正常人 (3.0 71±1.7) μg L(P <0 .0 1) ,其中 10 2例厚苔者 (占 6 7.1% )的h -EGF含量为 (4.2 70± 1.7) μg L ,也明显高于 5 0例薄苔者 (占 32 .9% )的h -EGF含量 (3.6 91± 1.2 ) μg L (P <0 .0 1)。 结论 :唾液中h -EGF含量与肿瘤病人舌苔增厚密切相关。