Osamu Tanizawa

Afferent fiber connections from lower brain stem to hypothalamus studied by the horseradish peroxidase method with special reference to noradrenaline innervation

SummaryAttempts were made to determine the afferent projections to the anterior hypothalamus including the preoptic area from the lower brain stem by means of the horseradish peroxidase method combined with monoamine oxidase staining to identify noradrenaline (NA) neurons. In addition to this technique, a histofluorescence analysis was performed. NA fibers in the medial part of the anterior hypothalamus were mainly supplied by A1 and A2 NA neuron groups, while the lateral part and periventricular zone received NA terminals from both pontine and medulla oblongata NA neuron groups. Furthermore, the present study indicated that there were direct projections to the anterior hypothalamus from non-noradrenergic neurons in the lower brain stem: nuclei raphe dorsalis, centralis superior, cells in the mesencephalic and pontine central gray matter, nuclei parabrachialis lateralis and medialis, cells around fasciculus longitudinalis medialis.

Gestational thyrotoxicosis and hyperemesis gravidarum: possible role of hCG with higher stimulating activity

OBJECTIVE The thyroid gland is physiologically stimulated in normal early pregnancy. However, clinical thyrotoxicosis in normal pregnancy has not been well described. In order to clarify this we examined thyroid function and thyrotoxic symptoms in relation to emesis in normal pregnancy. We also investigated the possible mechanism of gestational thyrotoxicosis.

Production of interleukin-6 by normal human trophoblast.

The placenta plays a number of important roles during pregnancy, some of which might be mediated by cytokines with multiple activities such as IL-6. Using an IL-6-dependent cell line, MH6o.BSF2, we showed that the placenta released IL-6 into the culture supernatant. Analysis of single-cell suspensions of placental cells determined the major source of IL-6 to be trophoblast. Using a mouse monoclonal antibody specific for IL-6 (alpha BSF2-I66), immuno-histochemical analysis of placental specimens demonstrated the localization of IL-6 only in the trophoblast layer. Additional immunocytochemical studies with single-cell suspensions of trophoblasts demonstrated the preferential presence of IL-6 molecules in syncytiotrophoblasts rather than cytotrophoblasts. The evidence that a high titer of IL-6 is produced spontaneously by syncytiotrophoblasts indicates that IL-6 may play immunological roles in fetomaternal interactions by means of IL-6-driven multiple immunoregulatory activities.

Binding Sites for Interleukin-6 in the Anterior Pituitary Gland

Interleukin-6 (IL-6) binding site in the rat anterior pituitary gland was characterized using radioiodinated human recombinant (hr) IL-6. Results showed that the anterior pituitary gland contained 170 binding sites per cell of a single class with a dissociation constant of 2.7 x 10(-9) M. The binding of 125I-hrIL-6 to the rat anterior pituitary gland was competitively inhibited by unlabeled hrIL-6, but not by hrIL-1 alpha, hrIL-1 beta, hrIL-2 or hr-interferon-gamma, indicating these binding sites are specific for IL-6. We also demonstrated mouse IL-6 receptor gene expression in the rat anterior pituitary gland by Northern blot analysis. Furthermore, the IL-6 receptor was detected on human gonadotrophs by the double immunofluorescence method. Our findings demonstrate the presence and expression of IL-6 binding site in the rat anterior pituitary gland and the presence of IL-6 binding site on human gonadotrophs, suggesting the important role of IL-6 binding site in pituitary hormone release in both species.

Detection of interleukin-8 (IL-8) in seminal plasma and elevated IL-8 in seminal plasma of infertile patients with leukospermia.

OBJECTIVE To determine if interleukin-8 (IL-8) is a normal constituent of seminal plasma and if leukospermia is a factor determining its elevation. DESIGN Seminal plasma from 58 men obtained by masturbation was examined for the presence of IL-8 using an IL-8 specific sandwich ELISA. Semen samples were obtained from 34 infertile men without leukospermia, 10 infertile men with leukospermia, and 14 proven fertile men. The correlation of amount of IL-8 in seminal plasma with some spermiogram parameters and the amount of polymorphonuclear (PMN) elastase was statistically evaluated. RESULTS Immunoreactive IL-8 was observed in the seminal plasma of all 58 subjects. The IL-8 titer in seminal plasma of patients with leukospermia (6.16 +/- 0.82 micrograms/L) was significantly higher than that in seminal plasma of patients without leukospermia (2.35 +/- 0.34 micrograms/L) and fertile men (1.64 +/- 0.29 micrograms/L). There was a high degree of correlation between PMN elastase and IL-8 levels in seminal plasma. CONCLUSIONS These findings demonstrate IL-8 to be in seminal plasma and elevated IL-8 levels in infertile patients with leukospermia.

The Behavior of Endometrial Hyperplasia: A Prospective Study

Objective: To clarify the behavior of endometrial hyperplasia in a prospective study.

Localization of three subtypes of Fcγ receptors in human placenta by immunohistochemical analysis

We investigated the localization of the three subtypes of (Fc gamma R) in the normal human placenta using immunohistochemical and immunocytochemical techniques with specific monoclonal antibodies. The analysis revealed that Fc gamma RI was expressed on Hofbauer cells, that Fc gamma RII was expressed on Hofbauer cells and endothelial cells of fetal vessels, while Fc gamma RIII was expressed on trophoblasts, especially syncytiotrophoblasts. Moreover, we demonstrated that the expression of Fc gamma RI and Fc gamma RII on Hofbauer cells and endothelial cells of the fetal vessels in the 1st trimester placenta was different from that in the 3rd trimester placenta. These results, therefore, indicate that the three subtypes of Fc gamma R in the human placenta may contribute to maintenance of placental functions, because each Fc gamma R molecule displays unique biological functions similar to those on leukocytes.

Alteration of the p53 tumor suppressor gene occurs independently of K-ras activation and more frequently in serous adenocarcinomas than in other common epithelial tumors of the human ovary

To clarify the role of the p53 tumor suppressor gene in the development of human ovarian epithelial tumors and to study the association of p53 alterations with K‐ras activation, a series of 70 common epithelial ovarian tumors from Japanese patients was studied. These included 31 serous adenocarcinomas, 12 mucinous adenocarcinomas, 5 mutinous tumors of borderline malignancy, 13 endometrioid adenocarcinomas, and 9 clear cell carcinomas. Allelic loss, recognized at the polymorphic site in codon 72 of the p53 gene, was detected in 14 of 36 (39%) informative cases by restriction fragment length polymorphism analysis and by single‐strand conformation polymorphism (SSCP) analysis of polymerase chain reaction(PCR)‐amplified DNA fragments. Mutations in the highly conserved regions of the p53 gene were detected by SSCP analysis of PCR‐amplifled fragments. Mutations were found in 22 of 70 (31%) ovarian tumors, including 1 of 5 mucinous tumors of borderline malignancy. Mutations were subsequently characterized by direct sequencing. Single missense base substitutions were detected in 13 ovarian carcinomas and in one case of mucinous tumor of borderline malignancy. Short (1‐8 bp) deletions and insertions were found in 8 cases. Mutations in the p53 gene occurred more frequently in serous adenocarcinomas (14/31, 45%) than in all nonserous types of malignant epithelial tumors combined (7/34, 21%;P=0.032). Point mutations in K‐ras were identified by dot blot hybridization analysis of PCR‐amplified fragments with mutation‐specific oligonucleotides and by direct sequencing. The overall frequency of K‐ras mutations was 19/70 (27%).K‐ras mutations were found in 12 of 17 (71%) mucinous tumors (8/12 mucinous carcinomas [67%] and 4/5 mucinous tumors of borderline malignancy [80%]), and occurred more frequently than in serous carcinomas (4/31, 13%;P=0.00009) or in all nonmucinous types of ovarian epithelial tumors combined (7/53, 13%; p=0.00002). These data suggest that different combinations of oncogenes and/or tumor suppressor genes may be involved in the genesis and development of histologically distinct categories of common epithelial tumors of the human ovary.

A Case-Control Study on Risk Factors for Uterine Endometrial Cancer in Japan

A case control study of 143 Japanese women with uterine endometrial cancer and 143 individually age‐matched controls was conducted to assess the risk factors for endometrial cancers in Japan. Among the characteristics studied, the following factors were significantly greater in the cases than in the controls: nulliparity (odds ratio for parity 1–3 and ≥4 versus nullipara are 0.40 and 0.02, respectively), obesity (odds ratio: 2.73), hypertension (odds ratio: 2.4), diabetes mellitus (odds ratio: 6.30), and a personal medical history of cancer (odds ratio: 3.06). The present study showed that Japanese women have the same risk factors for endometrial cancer as those reported in Western countries. The recent increase in the incidence of endometrial cancer in Japan may be largely attributed to the decrease in parity.

Placental interleukin-6 production is enhanced in intrauterine infection but not in labor

OBJECTIVE Because interleukin-6 is an important mediator in the host defense mechanism against infection and tissue damage, we studied the capacity of placentas with or without either labor or chorioamnionitis in the third trimester to produce interleukin-6. STUDY DESIGN The placental blocks were cultured, and their interleukin-6 titers were measured by a bioassay. RESULTS Placentas with labor produced a similar amount of interleukin-6 to placentas without labor. In contrast, placentas with chorioamnionitis produced much more interleukin-6 than the placentas with or without labor (p < 0.0001). CONCLUSION Placental interleukin-6 is thus surmised to participate in potentiation of the placental and fetomaternal defense mechanisms together with placental interleukin-1 during chorioamnionitis.