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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.

Notes: Several monoclonal antibodies (MAB) have been produced using an eccrine carcinoma cell line as an immunogen. One such MAB, SKH1, reacted with both the secretory portion and coiled duct of the eccrine and with the secretory portion of apocrine gland. SKH1, however, did not react with myoepithelial cells, intradermal ducts of both types of sweat gland, or with other components of normal axillary skin including the epidermis and follicular apparatus. The reaction was strongest if the specimen was fixed with 80% methanol, and moderate on non-fixed or acid-alcohol-fixed specimens. Only weak reaction was obtained on cold acetone-fixed specimens, and reaction was negative with formalin-fixed, paraffin-embedded tissues. SKH1 reacted positively with the cytoskeleton of the eccrine carcinoma cell line, Colo-16 and MCF-7. Applied to pathological skin specimens, SKH1 reacted with the tumor cells of clear cell hidradenoma, syringocystadenoma papilliferum, and extramammary Paget's disease. SKH1 also reacted with the tumor cells of meta-static adenocarcinomas arising from lung, breast and ovary. SKH1 did not react with the majority of tumor cells of eccrine poroma, but reacted with single–layered cells lining narrow ductal lumina. SKH1 did not react with epithelial cells lining cystic or ductal lumina of syringoma, but reacted moderately with the amorphous keratin–like substance filling the lumina. Immunoblot analysis revealed that SKH1 recognizes a 40 Kd sweat gland-associated antigen, and can be an aid to identifying tumors arising from sweat gland structures.

Notes: A 51-year-old imunosuppressed man presented with ulcerations of the abdominal wall. Biopsy of the ulcer margin was necessary for the diagnosis of cutaneous cryptococcosis. Since a variety of opportunistic organisms can present with non-specific cutaneous lesions, these infections must be ruled out by tissue diagnosis of all immunosuppressed patients. A review of 22 additional cases is included together with electron microscopic findings.

Notes: A hair matrix tumor showing an unusual tumor cell arrangement was found at the base of a solitary trichoepithelioma. Coexisting with solid epithelial islands and immature hair follicle-like structures, areas of alternating epithelial cords and hand-like stroma resembling the Verocay bodies of neurilemmoma or “ripplemarks” on waves were found. In other areas myxomatous degeneration of the stroma changed the rippling into a cribriform pattern. In some parts of the tumor there was a dense melanin pigment associated with MEL5 stained melanocytes. S-100 and GDI (OKT6) antigen stains demonstrated Langerhans cells scattered in the parenchyma and less frequently in the stroma. The majority of tumor cells were considered immature pilar cortical cells because of the following: 1. HKN-6 was strongly positive; 2. a large number of melanocytes were associated with tumor cells in some foci; 3. ultrastructurally immature tumor cells, which had electron-dense tonofilaments and many desmosomes, were transformed without production of trichohyalin granules into semikeratinized cells which showed nuclear degeneration and loss of electron density in tonofilaments. This tumor, however, has not attained the degree of differentiation observed in trichoblastoma (1) another example of an immature cortical cell tumor. Squamous eddy-like or horn pearl-like foci of incomplete keratinization and large keratin-filled cysts were also present within the immature parenchyma, indicating that some immature cells were differentiating toward non-cortical cells, as found in the outer sheath. We would like to designate this tumor “rippled pattern trichomatricoma”, a new entity.

Notes: Specimens from a patient with epidermolysis bullosa contained many elastic globes in the dermis. Ultrastructurally they were composed of (i) medium electron-dense amorphous substances, (ii) electron-dense round structures, and (iii) fine filaments. These various elements were seldom organized into typical normal elastic fiber and, therefore, it was difficult ultrastructurally to recognize them as such or components thereof. Immunohistochemically, elastic globes were strongly reactive with NKH-1, which stains elastic microfibrils, and antibody to serum amyloid P component (anti-SAP), which binds to elastic fiber micro-fibrils. However, elastic globes were negative with EKH-4 which recognizes 50 kd keratin of amyloid keratin and cytoid bodies. These findings suggested that elastic globes have a close immunologic profile to elastic fiber microfibrils, but not that of epidermal or epithelial keratin.