The skin of the amphibious fishes, Periophthalmus cantonensis and Boleophthalmus pectinirostris, was investigated by transmission electron microscopy (TEM). In both species the epidermis consists of superficial nonvacuolated epithelial cells, swollen epithelial cells with membrane limited cytoplasmic vacuoles, and basal epithelial cells in a single layer. Unicellular mucous glands, but no chloride cells are found in the epidermis of B. pectinirostris; in contrast there are chloride cells and no unicellular mucous cells in P. cantonensis. Intraepidermal blood vessels are a notable feature in the epidermis of P. cantonensis. Capillaries are distributed near the epidermal surface, offering an air-blood barrier of sufficient thinness (2-4 μm) for cutaneous respiration. The large blood vessels (arterioles and venules) are seen in the middle stratum of the epidermis and seem to be able to regulate blood flow in the skin. In B. pectinirostris, the dermal capillaries lie immediately below the superficial epithelial cells at the apex of a dermal bulge where the air-blood barrier is almost as thin as that of P. cantonensis despite locally different histology. In the spacious dermal bulges, the dermal tissue such as blood vessels, pigment cells, fibroblasts, and collagen fibers are scattered. Melanophores and two other types of chromatophores occur in the part adjacent to the blood vessel wall. The organization of the epidermis and blood vessels of the skin is discussed with regard to terrestrial life in these amphibious fishes. © 1992 Wiley-Liss, Inc.

ABSTRACT:Trans-3-hydroxycotinine is a major metabolite of nicotine in humans and is mainly excreted as O-glucuronide in smoker's urine. Incubation of human liver microsomes with UDP-glucuronic acid produces not only trans-3-hydroxycotinine O-glucuronide but also N-glucuronide. The formation of N-glucuronide exceeds the formation of O-glucuronide in most human liver microsomes, although N-glucuronide has never been detected in human urine. Trans-3-hydroxycotinine N-glucuronidation in human liver microsomes was significantly correlated with nicotine and cotinine Nglucuronidations, which are catalyzed mainly by UDP-glucuronosyltransferase (UGT)1A4 and was inhibited by imipramine and nicotine, which are substrates of UGT1A4. Recombinant UGT1A4 exhibited substantial trans-3-hydroxycotinine N-glucuronosyltransferase activity. These results suggest that trans-3-hydroxycotinine N-glucuronidation in human liver microsomes would be mainly catalyzed by UGT1A4. In the present study, trans-3-hy- Trans-3Ј-hydroxycotinine O-glucuronide is a major metabolite of nicotine in smoker's urine. Nicotine is metabolized to cotinine by CYP2A6 (Nakajima et al., 1996a), and cotinine is further metabolized to trans-3Ј-hydroxycotinine by CYP2A6 (Nakajima et al., 1996b). Glucuronide conjugates of nicotine, cotinine, and trans-3Ј-hydroxycotinine account for more than 40% of the nicotine dose (Byrd et al., 1992;Benowitz et al., 1994;Yamanaka et al., 2004). Nicotine and cotinine are metabolized to N-glucuronide (3-13 and 8 -20% nicotine dose, respectively), whereas trans-3Ј-hydroxycotinine is metabolized to O-glucuronide (8 -13% nicotine dose) in vivo. As far as we know, there is no information about the pharmacological activity of glucuronides of nicotine and its metabolites. However, it is emphasized that a first step of nicotine metabolism to cotinine extinguishes the pharmacological activity of nicotine. In general, glucuronidation is known as a detoxification pathway, since it enhances the elimination of compounds from the body. The theory would be true in glucuronidation of nicotine and its metabolites. Thus, glucuronidation is an important pathway of nicotine metabolism in humans. In our previous study, we clarified that nicotine and cotinine N-glucuronidation are catalyzed mainly by UGT1A4 (Nakajima et al., 2002b), a finding that was subsequently supported by Kuehl and Murphy (2003a). Recently, Kuehl and Murphy (2003b) detected N-linked glucuronide of trans-3Ј-hydroxycotinine by incubation with human liver microsomes. Nevertheless, the metabolite has never been detected in smoker's urine (Byrd et al., 1994). Since the trans-3Ј-hydroxycotinine N-glucuThis study was supported by an SRF grant for Biomedical Research in Japan and by Philip Morris Incorporated.Article, publication date, and citation information can be found at

Aim:While it has been reported that the prevalence of mental illness is higher in homeless people than in the national population, few studies have investigated the prevalence of intellectual and developmental disability among the homeless. In this study, we conducted a survey to comprehensively assess these mental problems among homeless people in Nagoya, Japan. Methods:The subjects were 18 homeless men. Mental illness was diagnosed with semi-structured interviews conducted by psychiatrists. We used the Wechsler Adult Intelligence Scale III to diagnose intellectual disability. Discrepancies between Wechsler Adult Intelligence Scale III subtest scores were used as criteria for developmental disability.Results: Eleven of the 18 participants were diagnosed with mental illness: six with mood disorder, two with psychotic disorder, and six with alcohol problems. The mean IQ of all subjects was 83.4 ± 27.4. The 95% confidence interval (CI) was 96.2-69.1. Seven participants were found to have intellectual disability. Three men showed discrepancies of more than 10 between subtest scores, and all of them were diagnosed with a mental illness. We divided the participants into four groups: those with mental illness only; those with intellectual disability only; those with both problems; and those without diagnosis. The men with intellectual disability only were significantly younger and had been homeless since a younger age than the other groups. Participants diagnosed with a mental illness had been homeless for longer than those without mental health problems. Conclusion:Although the sample size was limited, this study revealed the high prevalence of mental illness and intellectual disability, 61% (95%CI, 35-83%) and 39% (95%CI, 17-64%), respectively, in homeless people in Nagoya, Japan.

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