Scrotal skin replacement for extramammary Paget's disease--a technique

We describe a new method of "silk hat skin replacement" for extramammary Paget's disease in the scrotum. This method takes only a short time, and a scrotal raphe can be reconstructed.

Intra-oral fluoride retention 3 minutes after fluoride mouthrinsing in 4- to 5-year-old children: effects of fluoride concentration and rinsing time

This study was undertaken to explore the site-specific retention rate and the possibility of shortening fluoride (F) mouthrinsing time of kindergarten children. Fluoride retention after 10-, 20- and 30-second mouthrinsing was determined in 43 kindergarten children aged 4-5 years. Tooth surfaces were sampled by a paper point method. Fluoride concentrations in the salivary film on tooth surfaces increased from primary molars to primary incisors in the maxilla and decreased from primary molars to primary incisors in the mandible. The fluoride solution reached the primary molars even after a 10-second rinse, but F concentrations were higher after 20 s than after 10 s and significantly higher after 30 s than after 10 s. No significant difference was observed between 20 and 30 s. The average total F retained in the mouth was 0.13 mg after 20 s and 0.17 mg after 30 s. It was concluded that 30-second mouthrinsing, which is used extensively in Japanese kindergartens, can be shortened to 20 s.

Saturable absorbers incorporating carbon nanotubes directly synthesized onto substrates and fibers and their application to mode-locked fiber lasers

We present novel carbon-nanotube-based saturable absorbers. Using the low-temperature alcohol catalytic chemical-vapor deposition method, high-quality single-walled carbon nanotubes (SWNTs) were directly synthesized on quartz substrates and fiber ends. We successfully applied the SWNTs to mode lock a fiber laser producing subpicosecond pulses at a 50-MHz repetition rate.

Generation of single-walled carbon nanotubes from alcohol and generation mechanism by molecular dynamics simulations

Recent advances in high-purity and high-yield catalytic chemical vapor deposition (CVD) generation of single-walled carbon nanotubes (SWNTs) from alcohol are comprehensively presented and discussed on the basis of results obtained from both experimental and numerical investigations. We have uniquely adopted alcohol as a carbon feedstock, and this has resulted in high-quality, low-temperature synthesis of SWNTs. This technique can produce SWNTs even at a very low temperature of 550 degrees C, which is about 300 degrees C lower than the conventional CVD methods in which methane or acetylene is typically used. We demonstrate the excellence of the proposed alcohol catalytic CVD method for high-yield production of SWNTs when Fe-Co on USY-zeolite powder was used as a catalyst. At optimum CVD conditions, a SWNT yield of more than 40 wt % was achieved over the weight of the catalytic powder within the reaction time of 120 min. In addition to the advantages for mass production, this method is also suitable for the direct synthesis of high-quality SWNTs on Si and quartz substrates when combined with the newly developed liquid-based "dip-coat" technique to mount catalytic metals on the surface of substrates. This method allows easy and costless loading of catalytic metals without the need for any support or underlayer materials that were usually required in previous studies for the generation of a sufficient quantity of SWNTs on an Si surface. Finally, the result of molecular dynamics simulation for the SWNT growth process is presented to obtain a fundamental insight into the initial growth mechanism on the catalytic particles.

Ectoparasites of the Pallas squirrel, Callosciurus erythraeus, introduced to Japan

The squirrel Callosciurus erythraeus (Pallas) (Rodentia: Sciuridae) was intentionally introduced to Japan in 1935 and has become established throughout much of the country. Although they live mainly in forests, Pallas squirrels come into gardens and are frequently fed by people or kept as pets, so their ectoparasites could be of potential medical as well as veterinary importance. During 2001-2003 we conducted the first ectoparasite survey of Pallas squirrels in Japan. From 105 C. erythraeus captured in Kamakura District of Kanagawa Prefecture on Honshu Island, three types of ectoparasite were found: 52 specimens of the sucking louse Neohaematopinus callosciuri Johnson (Anoplura: Haematopinidae), 26 fleas Ceratophyllus (Monopsyllus) anisus Rothschild (Siphonaptera: Ceratophyllidae) and four nymphs of the tick Haemaphysalis flava Neumann (Acari: Ixodidae) on 22, 13 and one squirrels, respectively. Evidently in Japan C. erythraeus carries relatively few ectoparasite species; this may be a contributory factor to their invasive success. Further investigations are needed to assess risks of zoonotic transmission of plague or murine typhus by C. anisus, of louse-borne typhus by N. callosciuri and of tularaemia and especially Japanese spotted fever (Rickettsia japonica) by H. flava.

Hepatobiliary cystadenoma with mesenchymal stroma in a patient with chronic hepatitis C

Hepatobiliary cystadenoma was suggested to be uncommon and it is often difficult to make a differential diagnosis. We report a case of a 65-year-old woman who presented with changes in the structure of a cyst that had been observed for the previous 10 years. Diagnostic imaging revealed a 7-cm-diameter cystic lesion with internal septations and papillary projections in her liver. All laboratory test results were normal; however, cystic fluid carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 were raised, at 160 ng/ml andover 200,000 U/ml, respectively. Owing to changes in the structure of the cyst and the difficulty of differential diagnosis from cystadenocarcinoma, a complete surgical excision was performed. The histological findings indicated that the tumor consisted of a multilocular cyst lined by glandular cells (with cuboidal or tall columnar cystoplasm), which were immunohistochemically positive for cytokeratin, CEA, epithelial membrane antigen, and CA 19-9. The underlying stroma was composed of proliferating primitive spindle cells which were immunoreactive for vimentin, alpha-smooth muscle actin, muscle-specific actin, and desmin, and resembled ovarian stroma. From these findings, this tumor was diagnosed as hepatobiliary cystadenoma with mesenchymal stroma. Even though the tumor was previously diagnosed as a simple liver cyst, it was necessary to pay special attention to the changes in the structure of the cyst, using ultra sonography and/or computed tomography, bearing in mind hepatobiliary cystadenoma with mesenchymal stroma. The malignant potential of this tumor is stressed, and complete surgical resection is the recommended therapy.

Brain-derived neurotrophic factor modulates glucagon secretion from pancreatic alpha cells: its contribution to glucose metabolism

AIM

Brain-derived neurotrophic factor (BDNF) reduces plasma glucose levels in obese db/db diabetic mice and is speculated to produce its effects via the hypothalamus, the regulatory centre of satiety and the autonomic nervous system. The potential effect of BDNF directly on peripheral endocrine organs, however, remains to be clarified. Here we report the effects of BDNF on hormonal secretion from pancreatic islets of Langerhans using their isolated culture.

METHODS AND RESULTS

In an immunohistochemical study, mouse pancreatic alpha cells were stained specifically with the anti-TrkB (a specific receptor for BDNF) antibody. After 7 days culture of isolated islets of the normal mouse pancreas, 10 ng/ml BDNF decreased the secretion of glucagon per 6 h significantly less than that of the control (p = 0.016). In contrast, there were no significant changes in insulin secretion or glucagon and insulin contents in the islets cultured under the same conditions. In vivo administration of BDNF (10 mg/kg/day) to normal mice for 7 days significantly decreased their food consumption (p < 0.05). The fasting plasma glucose levels were decreased on day 7 compared with day 1 more significantly in BDNF-treated mice (p = 0.043) than in pair-fed control mice (p = 0.14). In newborn BDNF-knockout mice, fasting plasma glucose levels increased in the order of homozygote, heterozygote and wild type (p = 0.033). No apparent immunohistochemical abnormality was observed for pancreatic glucagon in the BDNF-knockout mice.

CONCLUSION

These data suggest that BDNF affects glucose metabolism not only with its anorectic effect but also with modulated glucagon secretion from pancreatic alpha cells.

Increase in serum 7S domain of type IV collagen and N-terminal propeptide of type III procollagen levels with normal serum transaminase levels after long-term oral administration of Tegaful-Uracil

To evaluate whether oral administration of Tegaful-Uracil (UFT(R)), a biochemical modulator of 5-fluorouracil that contains tegafur and uracil, can induce hepatic fibrosis, serum 7S domain of type IV collagen and N-terminal propeptide of type III procollagen levels were measured in 63 UFT(R)-treated, 38 tegafur-treated and 40 untreated patients. Serum transaminase and bilirubin levels were normal in almost all patients. Serum levels of 7S collagen and type III propeptide increased in 25 and 17% of the UFT(R)-treated patients, respectively, although a majority of tegafur-treated and untreated patients showed no increase in these markers. The patients with the elevated levels demonstrated mild or moderate hepatic fibrosis without necroinflammation in the liver. Both serum levels decreased markedly after the discontinuation of UFT(R). These findings suggest that long-term oral administration of UFT(R) can induce hepatic fibrosis without the elevation of serum transaminase levels and necroinflammation in the liver, and serum 7S collagen and type III procollagen are of diagnostic value for UFT(R)-induced hepatotoxicity.

Iron lactate induction of pancreatic and endometrial proliferative lesions and a lack of increased tumors in a 104-week carcinogenicity study in F344 rats

Iron lactate has been used as a food additive for iron supplementation. The present study was conducted to determine whether it might have carcinogenic potential. A total of 150 male and 150 female Fischer 344 rats were divided into three groups and fed basal diet containing 0, 1 or 2% of iron lactate for 104 weeks. No iron lactate-induced tumors were observed in any groups, although the incidences of pancreatic acinar cell and endometrial gland hyperplasias were increased in males and females, respectively, in the 2% group. Thus our in vivo animal data indicate that iron lactate lacks carcinogenicity in male and female F344 rats. However, estrogenic effects might be concluded based on the data for endometrial lesions. In a second experiment, an estrogen responsive rat pituitary tumor cell line, MtT/Se, and a human breast cancer cell line, MCF-7, were therefore employed to examine the estrogenic potential of iron lactate with regard to receptor binding affinity and ERE-reporter gene activation. Results in both cases were negative. Further investigations are needed to elucidate the mechanisms of induction of pancreatic and endometrial proliferative lesions by iron lactate.

Effects of sumatriptan on cerebral blood flow under normo- and hypercapnia in rats

To investigate further the pharmacological mechanism of an anti-migraine drug, sumatriptan, a 5-HT1B/1D receptor agonist, we studied its effect on the cerebral circulation in seven anaesthetized rats, particularly during hypercapnia. After injection of 0.6 or 6.0 microg/kg sumatriptan succinate, no significant change in cerebral blood flow (CBF) was observed either in the striatum or in the parietal cortex. The increase in CBF both in the parietal cortex and the striatum during 5% CO2 inhalation was significantly less when sumatriptan succinate 6.0 microg/kg was injected. Sumatriptan appeared to have a vasoconstrictor effect on the relaxed vessels by CO2 inhalation. This mechanism might be attributable to vasoconstriction through activation of 5-HT1B receptors located in the vascular smooth muscle rather than 5-HT1B receptors in the vascular adventitia.

Hyperendothelinemia and ICG clearance in alcoholic and nonalcoholic cirrhosis

Plasma endothelin (ET) levels are generally increased in cirrhosis patients in line with the severity of disease; however, the pathophysiological significance remains to be clarified. We evaluated the plasma ET levels in 49 patients with alcoholic cirrhosis and in 53 patients with nonalcoholic cirrhosis of the same disease severity. The plasma ET level was significantly elevated in alcoholic patients (P < 0.0001) and slightly so in nonalcoholic patients (P < 0.01); the difference was significant between the groups (P < 0.0001). The plasma ET level was positively correlated with the Child-Pugh score (P < 0.0001) and negatively correlated with prothrombin index (P < 0.001) and indocyanine green (ICG) clearance (P < 0.0001). The plasma ET level decreased 32% in alcoholic patients after abstinence (P < 0.001), but remained correlated with ICG clearance (P < 0.001) and the Child-Pugh score (P < 0.01), but not with prothrombin index. Regression analysis revealed that the plasma ET level was correlated with estimated hepatic blood flow and alcohol abuse. These findings suggest that hyperendothelinemia in cirrhosis patients is related to alcohol abuse and disease severity, especially to impaired hepatic hemodynamics.

A comparison of serum leptin concentrations in obese and normal weight Japanese women with regular menstrual cycle

Leptin is a protein that is synthesized and secreted from adipose tissue. We examined the changes in serum leptin level during the menstrual cycle in 5 normal and 5 obese Japanese women, and compared the data with those of serum estradiol (E2) and progesterone (P4) concentrations. Serum leptin levels were highly correlated with body mass index (BMI) and percent body fat, being higher in the obese group than in the normal group. In the obese group, serum leptin level increased in the luteal phase in parallel with the rise in the serum E2 level. In the normal group, however, there was no significant change in serum level during the menstrual cycle. These results suggested that the serum leptin levels were influenced by the phase of menstrual cycle, probably through the action of E2, in different ways for obese and non-obese women.

[Discovery of the adult Schistosoma japonicum, a causative agent of Schistosomiasis in the Katayama area of Hiroshima Prefecture]

People in the Katayama area of Hiroshima Prefecture had been afraid of a curious disease for a long time. The causative agent for the disease had not been identified through the beginning of the 20th century when it turned out that a human parasitic trematode, Schistosoma japonicum, had been afflicting the inhabitants, causing this disease. This was made clear mainly by two medical doctors, Akira Fujinami and Ryuzo Yoshida, much before 1909. The memoir on the disease described by a herb doctor, Yoshinao Fujii (1847), was made known by A. Fujinami to medical scientists in 1909.