Library

Notes: The prototypic pineal hormone, melatonin reputedly exerts many functional effects on mammalian skin and/or its isolated cell populations in culture (e.g., melanogenesis inhibition, melanocyte growth inhibition, regulation of seasonal changes in the pelage), and is recognized as a potent free radical scavenger. In mammals, two types of high-affinity membrane melatonin receptors, MT1 and MT2 have been identified, which inhibit adenylate cyclase activity to decrease the intracellular level of cAMP. Low-affinity membrane receptor MT3/QR2 have also been identified, though the mechanism has not been cleared yet. Melatonin is also a natural ligand of nuclear transcription factor ROR(α and β), which is suggested to regulate cell cycle negatively via target gene such as p21WAF/CIP1. Due to its lipophilic structure, melatonin also enters through both the plasma and nuclear membrane, and acts as a potent free radical scavenger to protect macromolecules, in particular DNA. Melatonin demonstrates differential – and often still confusing seemingly contradictory– effects on cell activity in many different systems, which may be explained by this multitude of signaling pathways that are modulated by melatonin bioactivity. Recently, cultured epidermal and follicular melanocytes, keratinocytes, and fibroblasts, have also been found to display the enzymatic activity of arylalkylamine N-acetyltransferase and hydroxyindole -O- methyltransferase for melatonin synthesis. However, little is known about the cutaneous expression and regulation of melatonin and its receptors in situ, and the functional role of melatonin in normal skin and hair follicle biology is still obscure. In order to study whether murine hair follicles in situ are indeed direct peripheral melatonin targets, the follicular expression of MT1, MT2 and/or RORα are investigated. Immunohistochemistry revealed that C57BL/6 mouse hair follicle keratinocytes in situ show prominent MT1-like immunoreactivity (IR), which changed substantially in a hair cycle-dependent manner. RORα-like IR was also detected in murine hair follicles, and also displayed hair cycle dependence. RT-PCR of MT1 and MT2, and real time PCR for MT1, MT2 and RORα on C57BL/6 mice skin cDNA revealed that all three genes are transcribed in normal mouse skin, and demonstrated that their expression/transcription is hair cycle-dependent. In conclusion, normal murine hair follicles are indeed a prominent, direct target for melatonin bioregulation, through MT1, MT2 and RORα melatonin receptors and that at least some of these regulators are functionally active in situ. The observed hair cycle dependence of melatonin receptor expression suggests a role of melatonin in hair cycle control.

Notes: 1. The mechanisms involved in the fine adjustment of iris sphincter muscle tone are largely unknown. The aim of the present study was to clarify the effects of adrenomedullin on the resting tension of the bovine isolated iris sphincter muscle.2. The motor activity of the bovine isolated iris sphincter muscle was measured isometrically. The effects of adrenomedullin on resting tension were analysed in the presence of indomethacin. The presence of adrenomedullin mRNA in the preparation was determined by reverse transcription–polymerase chain reaction. Immunolabelling for adrenomedullin was also performed.3. Adrenomedullin significantly decreased the resting tension of the muscle. The relaxant effect of adrenomedullin was significantly inhibited by adrenomedullin (22–52), a putative antagonist for the adrenomedullin receptor, or calcitonin gene-related peptide (CGRP) (8–37), a putative antagonist for the CGRP1 receptor. The relaxant effect was almost completely blocked by a combination of adrenomedullin (22–52) and CGRP (8–37).4. The relaxant effect of adrenomedullin was also significantly diminished by 2′,5′-dideoxyadenosine, an inhibitor of adenylate cyclase, NG-nitro-l-arginine, an inhibitor of nitric oxide synthesis, or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, an inhibitor of soluble guanylate cyclase.5. Reverse transcription–polymerase chain reaction analysis showed that adrenomedullin mRNA was expressed in the muscle strip. Immunopositive staining for adrenomedullin was detected in blood vessel cells and in the iris sphincter muscle cells.6. These results suggest that adrenomedullin may be an autocrine and paracrine regulator of the resting tension of the iris sphincter muscle. Its biological effects may be due to the direct involvement of adrenomedullin receptors and also to the stimulation of CGRP1 receptors. The stimulation of these receptors by the peptide leads to the activation of adenylate cyclase and soluble guanylate cyclase and subsequent relaxation of the muscle strip.

Notes: Objective:  The aim of this study was to determine whether or not we could distinguish uterine papillary serous carcinoma (UPSC) from other types of endometrial cancer by cytology.Methods:  We examined the cytological findings of the endometrium from five cases with UPSC and compared them with 10 cases with endometrioid adenocarcinoma, grade 1 (G1). A morphometric analysis was performed. Cytological samples from the cervix and ascites of the patients with UPSC were also reviewed.Results:  All five patients had FIGO stage III and IV tumours. Three patients died of the disease and two are still alive with disease. The tumour cells of UPSC tended to be shed in papillary clusters with a tumour diathesis. Psammoma bodies were seen only in UPSC. The frequency of irregular-shaped nuclei, membrane thickness and eccentric nuclei in UPSC was higher than in G1. The chromatin pattern was coarsely granular, and both anisonucleosis and bare nuclei were prominent in UPSC. Cytomorphometrically, the maximum diameter of the nuclei in UPSC was significantly greater than that in G1. The nucleoli were also more often seen in UPSC than in G1. The findings of the nuclei and nucleoli in the cervical and peritoneal fluid cytology closely resembled those in endometrial smears. The features of the cervical smears and peritoneal fluid cytology were different from those of endometrial cytology regarding clear background and small clusters of cells.Conclusion:  As the endometrial cytology findings accurately suggested the histological diagnosis of UPSC, the diagnosis of UPSC was confirmed in this study by endometrial cytology. The cytological diagnosis of UPSC should be based on the findings of tumour diathesis, psammoma bodies and papillary clusters composed of tumour cells with enlarged nuclei and numerous nucleoli.

Notes: Objective:  Early cervical adenocarcinoma (ECA) with a tumour depth of 〈3 mm has a good prognosis. To clarify the cytological features of ECAs with depth 〈3 mm, these were compared with those of ECA with 3–5 mm and invasive adenocarcinoma (IA) invading the cervical wall with more than 5 mm in depth.Methods:  The cervical cytological features of ECAs with depth 〈3 mm (14 cases) were compared with those of ECA with 3–5 mm (four cases) and IA (13 cases). Cytologically, the presence or absence of tumour diathesis, number of atypical cells, crowded cell groups, groups with glandular structures, feathering, groups with palisading borders, rosettes, clusters, cell shape and size, nuclear shape and size, nucleolar shape and size, chromatin distribution, border and character of cytoplasm, and single cell pattern were evaluated.Results:  A tumour diathesis was seen in five of 14 ECA 〈3 mm in depth (36%), all four ECA with 3–5 mm (100%) and 11 of 13 IA with more than 5 mm (85%). Single cells, macronucleoli and coarsely granular chromatin pattern were less frequent in ECA of 〈3 mm than that in ECA with 3–5 mm and IA. The number of atypical cells and glandular structures in ECA was significantly less than that in IA. Cell crowding, feathering, palisading and rosettes were common in both ECA and IA.Conclusion:  The characteristic cytological features of ECA with depth 〈3 mm, having a good prognosis, were clean background, fewer single cells and macronucleoli, and less frequent coarsely granular chromatin pattern compared with those in ECA with 3–5 mm and IA. The number of atypical cells and glandular structures in ECA was significantly less than that in IA. Familiarity with the cytological features of ECA and its mimics is essential.

Notes: The fabrication of Al2O3-ZrO2~Ni functionally graded pipes has been investigated byslurry coating and pressureless sintering process. Each slurry of Al2O3-ZrO2~Ni mixture and Ni was coated in order on the Al2O3-ZrO2 pipes formed by slip casting method with those slurries. The obtained laminar green pipes were 30 mm in diameter and approximately 90 mm in length. The laminar green pipes were sintered for 2 hours at 1430℃ in a vacuum. The structure of pipes fabricated by this method was optically and microscopically examined and the graded distribution was examined by an EPMA analysis of Al and Ni. The pipes with 2 layers of Al2O3-ZrO2 and Ni had crevices in the bonding interface. Some functionally graded pipes with 3 layers were free from cracks and warps without porosity, and each interface had the complete bonding