Modeling of segmentation clock mechanism in presomitic mesoderm.

Somite is sequentially generated in a head-to-tail order by segmentation of the mesenchymal tissue called presomitic mesoderm (PSM). The segmentation occurs periodically at the anterior end of the PSM, and this periodic segmentation has been suggested to be regulated by a molecular clock. In mouse PSM, the segmentation-related genes change their expression every 120 minutes, and this cyclic expression is essential for regular somite segmentation. In this study, a molecular mechanism of segmentation clock involving Wnt and Delta-Notch signaling pathways is modeled, and reality of the model structure is investigated through simulating biological findings. One dimensional array of the cellular clock models is constructed to simulate spatio-temporal dynamics of the gene-expressions in the PSM. The simulation result suggests that the Wnt gradient across the PSM is involved in the dynamics under concern.

[Testicular malignant lymphoma: report of two cases].

One patient was a 79-year-old man, who exhibited right scrotal swelling and the other patient was a 73-year-old man, who exhibited left scrotal swelling. Both patients received high orchiectomy under the diagnosis of testicular tumor and the histopathological diagnosis in both patients was non-Hodgkin's lymphoma. Case 1 was diffuse, medium-sized B cell type, and case 2 was diffuse, mixed B cell type. Several examinations revealed no apparent additional involvement. Neither patient received any adjuvant chemotherapy nor postoperative irradiation. In case 1, for a period of 4 years following high orchiectomy, the patient has been doing well. In case 2, 2 years and 6 months postoperatively, para-aortic lymph node swelling occurred, and chemotherapy was initiated with THP-COP but the patient died at 3 years and 3 months after high orchiectomy.

[A case of metastatic liver tumors from prostatic cancer responding to intra-arterial infusion chemotherapy with CDDP and ifosfamide using implantable port].

A 65-year-old man was admitted to our hospital complaining of upper abdominal pain, nausea and appetite loss during the treatment for the prostatic carcinoma. Computed tomography revealed multiple liver metastases. The patient was treated by intra-arterial infusion chemotherapy with, cisplatinum (CDDP) and Ifosfamide using an implantable port. The metastatic lesions were significantly decreased in size and number but CR was not achieved. CDDP was ceased at the total dose of 960 mg. The patient died due to brain metastases 20 months after the start of intra-arterial chemotherapy.

Interlaboratory validation of the in vitro eye irritation tests for cosmetic ingredients. (5) Skin(2TM) ZK1100 and tissue equivalent assay.

Skin(2TM) ZK1100 (ZK1100) assay and tissue equivalent assay (TEA, Skin(2TM) ZK1200) are human dermal models. These assays were evaluated as alternatives to the Draize eye irritation test (Draize test) in rabbits. Thirty-nine cosmetic ingredients were selected and used as test substances. The ZK1100 assay was conducted according to an original protocol provided by Advanced Tissue Sciences, a kit supplier. The TEA assay followed a protocol developed by Osborne et al., (1995a). Coefficients of variation (CV) ranged from 11.7 to 133 in results from the ZK1100 assay; three test substances showed the CVs more than 100. These were cetyltrimethylammonium chloride (S3-7), domiphen bromide (S3-11) and di(2-ethylhexyl) sodium sulfosuccinate (S3-14). Acid Red 92 (S2-3) was excluded from data analysis because its absorbance interfered with the endpoint of ZK1100 assay. The CVs from the TEA assay ranged from 31.8 to 119; two test substances showed the CVs more than 100. These were acetic acid and glycolic acid (S3-13). Butanol (S3-9) was excluded from the analysis because it was assumed to volatilize during a sample preparation. Pearson's coefficient of correlation with maximum average Draize total score (MAS) and 24hr score from the Draize tests were -0.71 and -0.72 for the ZK1100 results and -0.63 and -0.60 for the TEA results. When a MAS of 15 was set as a breakpoint for the classification of eye irritancy on Cooper's plots comparing the in vitro and the Draize data, the ZK1100 results showed five false positives and four false negatives; the TEA results showed three false positives and no false negatives.

[A patient complaining of right hypochondralgia with back pain. Aortic dissection or cholelithiasis?].

A 70-year-old woman with a past history of cholecystolithiasis was admitted to a local clinic because of right hypochondralgia with back pain. Since physical examination revealed Murphy's sign, this patient was diagnosed as acute cholecystitis. The ultrasonographic examination of the gallbladder showed a stone of the cystic duct with no definitive wall thickening. CT scan revealed dissection of the abdominal aorta. She was then referred to our hospital for further examinations. She was observed in the cardiac care unit to determine whether the aneurysm and cholecystitis were in an acute or chronic state. Blood examinations and enhanced CT scan showed that her clinical symptoms originated not from cholelithiasis but from acute closing aortic dissection, Stanford classification type B. Close cooperation with a highly developed medical facility is essential when diagnosing elderly patients with symptoms open to a variety of interpretation.

Purification and properties of phospholipases A2 from the crown-of-thorns starfish (Acanthaster planci) venom.

Two phospholipases A < inf2 (named AP-PLA2-I and II) were purified from the crown-of-thorns starfish (Acanthaster planci) venom. Both enzymes were confirmed to be PLA2s, based on the results that they showed hemolytic activity only in the presence of phosphatidylcholine (PC) and also released fluorescent fatty acids from PC with labeled fatty acids at the sn-2 position. The enzyme activity of both PLA2s was enhanced by Ca2+ but reduced by Cu2+ and Zn2+. The molecular mass of AP-PLA2-I was estimated to be 28 kDa by gel filtration and 15 kDa by SDS-PAGE, indicating that AP-PLA2-I is a dimer composed of the same subunit. In contrast, AP-PLA2-II was judged to be a monomer with a molecular mass of 12 kDa (gel filtration) or 15 kDa (SDS-PAGE). The amino acid compositions of the two enzymes were comparable to each other; Asx, Glx and Gly were rich in both molecules, while Met, His and Trp were poor. Analyses by a sequencer determined the first 62 amino acid residues for both PLA2s. In the AP-PLA2-I preparation, minor amino acids were additionally found at 17 positions, suggesting the coexistence of another PLA2-component. As compared to the N-terminal sequences of the known PLA2s, both AP-PLA2-I and II were identified as class I enzymes not only because they have Cys-11 and lack Cys-51 but also because they contain the elapid loop in the region 53-61.

High expression of the tec gene product in murine testicular germ cells and erythroblasts.

Tec is a novel non-receptor-type protein tyrosine kinase that was originally identified from a murine liver cDNA library. While the function of Tec remains unknown, it was shown recently that two Tec-related kinases are involved directly in the growth and differentiation of bone marrow stem cells. As the localization of Tec protein has not been reported yet, immunohistochemical and immunochemical studies of various murine organs were conducted in the present study to clarify which cells express this kinase protein. An intense immunohistologic reaction was observed in neonatal and adult testicular germ cells, and neonatal and fetal hepatic erythroblasts. In addition, a clear immunostaining was noted in neonatal and adult tubal epithelial cells, hepatocytes, basal cells of the non-glandular stomach, foveolar epithelium of the glandular stomach, sebaceous cells of the skin and fetal cartilage. The immune reaction of germ cells and erythroblasts was observed in the cell membrane, although this protein does not have a transmembrane domain. Supportive western blotting of testis, adult liver, spleen and heart of adult C.B-17 mice with the use of anti-Tec antibody demonstrated a heavy 70 kDa band in the liver and testis, and a much weaker, small band in the heart and spleen. These results suggest that Tec protein has a specific role in testicular germ cells and erythroblasts.

BCL-6 gene product, a 92- to 98-kD nuclear phosphoprotein, is highly expressed in germinal center B cells and their neoplastic counterparts.

The BCL-6 gene is known to be located on chromosome 3q27, at the breakpoint of the 3q27-associated translocations that occur frequently in human non-Hodgkin's lymphomas (NHLs). To identify the BCL-6 protein, two antibodies that recognized distinct domains of this protein were raised in rabbits. Immunoprecipitation and immunoblotting of lysates of BCL-6-expressing cells using both antibodies showed a broad 92- to 98-kD band. Dephosphorylation of BCL-6 protein reduced the size of this band to 87 kD, suggesting that BCL-6 may be expressed in a phosphorylated form. Immunostaining with both antibodies showed that BCL-6 protein was localized in the nuclei of most of the germinal center B cells and a small number of marginal zone B cells. Furthermore, BCL-6 protein was expressed in follicular, Burkitt's, and diffuse large B-cell lymphomas. These results suggest that the BCL-6 protein, expressed in B cells of the germinal centers which are important in the maturation of immune responses, may play some physiological role(s) in the germinal center B cells.