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Notes: Characlcristic moniliform hairs of monilcthrix were ultrastructurally examined. By scanning electron microscope, nodes and internodes were seen alternating on the affected hair; the nodes were normal in apparance and thickness, while the internodes were thin and showed ridges and flutes. By transmission electron microscope, the cross sections of the internodes revealed wrinkling of the hair coticular cells and a reduced number of the cortical cells. Cross sections of the cortical cells per se showed a similar size and a normal keratin pattern in both nodes and internodes, compared with those of control hairs from normal individuals. From these findings, the internodes seemed to be the pathological portions of the monilifonn hair, and such abnormal thinning of hair shaft might tie caused by a periodical dysfunction of the hair matrix, especially in the hair cortex.

Notes: Tissues peripheral to well-developed papules of colloid milium were chosen for biopsy and electron microscopy examination. Evidence was presented that colloid is derived from elastic fibres through sequential degenerative changes. In the upper to middle dermis of the peripheral tissue, a number of abnormal masses in the vicinity of small colloid depositions were observed. Ultrastructurally, those abnormal masses were degenerating elastic fibres in which “electron-dense layers” of normal elastic fibre increased in amount, although their electron density diminished. Electron-light layers were gradually diminished in quantity. Degenerated elastic fibres finally became granulo-fibrillar and were indistinguishable from colloid. Many fibrils which closely resembled 10 nm tubular microfibrils of normal elastic fibre were observed in the granulo-fibrillar substance. Since one stage of the degeneration of elastic fibre which eventually leads to the formation of colloid milium was very similar to that of actinic elastosis, a direct role of sunlight in the formation of colloid milium is suggested.

Notes: During starvation, counterregulatory responses to loss of food (i.e. responses that lead to an increase in appetite) occur in the central nervous system (CNS). This study was designed to examine whether middle-aged rats show greater or smaller behavioural, peripheral and central hormonal responses during starvation compared to young rats. In experiment 1, refeeding following 4 days of starvation was measured in both middle-aged (72-week-old) and young (9-week-old) rats. The level of refeeding was similar to each prestarved level until 3 days after the end of starvation in both groups. From the 4th day, the level of refeeding in young rats increased and reached beyond the prestarved level, whereas refeeding in middle-aged rats remained similar to the prestarved level. Thus, overall refeeding throughout 7 days was greater in young rats than in middle-aged rats. In experiment 2, middle-aged and young rats were starved for 4 days and were killed in the morning. Middle-aged rats showed a smaller plasma corticosterone response than that of young rats. The magnitude of decreases in plasma glucose, insulin and leptin was similar in both groups. In the arcuate nucleus, the starvation-induced increase in neuropeptide Y (NPY) mRNA and the decrease in proopiomelanocortin (POMC) mRNA were smaller in middle-aged rats than in young rats. In contrast, the starvation-induced decrease in corticotrophin-releasing hormone (CRH) mRNA in the hypothalamic paraventricular nucleus was greater in middle-aged rats than young rats. The magnitude of decrease in type-2 CRH receptor mRNA in the ventromedial hypothalamus was similar in both groups. The results indicate that (a) ageing impaired refeeding response (b), middle-aged rats showed the same directional neuropeptide mRNA responses as seen in young rats during starvation and (c) the magnitude of these counterregulatory responses in the CNS in middle-aged versus young rats was not uniform, but rather was site-specific or neuropeptide-specific. This study suggests the importance of NPY and POMC responsiveness in the arcuate nucleus in the age-related differences resulting from starvation-induced refeeding.

Notes: Although the SAA1 and SAA2 protein isoforms (A-SAA) of the serum amyloid A (SAA) family of acute phase reactants have been found in a number of extrahepatic tissues; the site of synthesis of extrahepatic SAA remains to be clarified. To investigate site(s) of synthesis of the SAA protein localized to atherosclerotic plaque, expression of the SAA1 and SAA2 genes by cultured human aortic smooth muscle cells (HASMC) was investigated. A-SAA protein isoforms were detectable by immunoblot analysis in the culture medium of HASMC. Both A-SAA and C-SAA (SAA4) mRNA isoforms were constitutively expressed by HASMC, but not, however, by the human umbilical vein endothelial cells. Expression of A-SAA mRNA by HASMC was upregulated by corticoid hormones including dexamethasone (Dex), corticosterone, hydrocortisone, and aldosterone, but not by the cytokines interleukin (IL)-1, IL-6, and tumour necrosis factor (TNF)-α alone. Dex stimulation of A-SAA mRNA was time and dose dependent from 6 to 48 h. The threshold concentration for upregulation of A-SAA mRNA in HASMC by Dex was between 0.1 and 1 nm. IL-1, known to upregulate extrahepatic A-SAA gene expression in other cell systems only slightly, if at all, upregulated Dex-induced A-SAA expression by HASMC. Thus, it is possible that some of the A-SAA protein in the vascular wall (atherosclerotic plaques) can originate from smooth muscle cells. In consideration of recent reports that A-SAA modulates the inflammatory process and lipid synthesis, A-SAA can potentially serve as a physiological regulator of smooth muscle cell homeostasis within that, in a disease state, participates in the formation of atherosclerotic plaques.

Notes: In our previous study, apparent reduction of glucocorticoid receptor (GR) mRNA was seen in the hippocampus and the hypothalamic paraventricular nucleus (PVN) during repeated immobilization (IMO) stress, but not following starvation. Our laboratory has also shown that the sp1 activates, whereas tumour suppressor p53 represses the promoter activity of GR gene. In an attempt to reveal the possibility that transcription factors such as sp1 and/or p53 are involved in the regulation of GR mRNA expression in the hippocampus and in the PVN in vivo, we examined the expression of GR mRNA, p53 mRNA, and sp1 mRNA in the hippocampus and in the PVN during repeated IMO and following starvation. In addition, the expression of these mRNAs was examined in the anterior pituitary, another GR-rich area. GR mRNA in all subfields of the hippocampus was robustly decreased, while GR mRNA in the anterior pituitary was increased, 24 h following 4 × IMO (2 h daily, for 4 consecutive days) and immediately after 5 × IMO. GR mRNA in the PVN was significantly decreased immediately after 5 × IMO, but not at 24 h after 4 × IMO. Conversely, p53 mRNA in the PVN and hippocampus was increased, whereas p53 mRNA in the anterior pituitary was decreased, 24 h following 4 × IMO and immediately after 5 × IMO. Sp1 mRNA was unchanged in all areas examined following repeated IMO. Following 4 days of starvation, neither GR mRNA, p53 mRNA nor sp1 mRNA showed any changes in the PVN and the hippocampus, except there was a minor decrease in GR mRNA in CA1-2. In the anterior pituitary, 4 days of starvation induced a minor, but significant increase in GR mRNA, whereas it decreased p53 mRNA. Overall, regression analyses revealed a negative correlation between GR mRNA levels and p53 mRNA levels in CA1-2 and dentate gyrus of the hippocampus and in the anterior pituitary. GR mRNA in the PVN also showed a tendency towards the negative correlation with p53 mRNA levels. The results raise the possibility that p53 negatively regulates GR mRNA expression in the PVN, the hippocampus and the anterior pituitary during repeated immobilization stress.

Notes: Regulation of acute-phase serum amyloid A (A-SAA) synthesis by proinflammatory cytokines and steroid hormones in human aortic smooth muscle cells (HASMCs) is distinct from that in HepG2 cells. To study the cis- and trans-activating promoter element involved in the SAA1 gene expression by HASMCs and HepG2 cells, we constructed plasmid vectors for luciferase reporter gene assay with varying lengths of SAA1 upstream regulatory region (up to 1431 bp), and examined their response to proinflammatory cytokines and/or steroid hormones. The corresponding vectors with the SAA4 upstream regulatory region served as controls. The presence of proposed transcriptional regulatory factors binding to these regions was confirmed immunohistochemically.The sequences of 1478 and 1836 bp of the SAA1 and SAA4 5′-flanking regions were determined, respectively. SAA1 promoter transcription in cultured HASMCs was upregulated not by proinflammatory cytokines, but rather by glucocorticoids. This differed from HepG2 cells, in which SAA1 promoter transcription was upregulated synergistically by proinflammatory cytokines and glucocorticoids. The promoter activity of a series of truncated SAA1 promoter constructs measured using the reporter gene assay showed that the 5′-region from −252 to −175, containing a consensus site for CCAAT/enhancer binding proteins α,β (C/EBPα,β), was essential for SAA1 induction in HASMCs. In HepG2 cells, the 5′-region from −119 to −79, containing a nuclear factor kappa-B (NFκB) consensus sequence, was essential for the induction. The functional significance of the C/EBP site as indicated by the immunohistochemical result was that in HASMCs anti-C/EBPβ reactivity was shifted from the cytoplasm to the nuclei.We have, therefore, demonstrated that the region containing the C/EBPα,β consensus binding site between the bases −252 and −175 is important for the glucocorticoid-induced SAA1 gene expression in HASMCs but not in HepG2 cells.