Primary carcinoid tumor of the larynx and review of the literature

Primary carcinoid tumor of the larynx is very rare. This is the fifth case reported in the literature and the first autopsy case of laryngeal carcinoid. The early manifestation of the present case was multiple metastasis to the skin. At autopsy there was a laryngeal tumor associated with widespread visceral and cutaneous metastases. The tumor proved to be carcinoid tumor by histological, histochemical and electron microscopic findings.     

Sensorless estimation of pressure head and flow of a continuous flow artificial heart based on input power and rotational speed

The present study has proposed a new method for estimating the pressure head (P(t)[mm Hg]) and flow (Q(t)[L/min]) of a centrifugal pump on the basis of voltage (V(t)[V]), current (I(t)[A]), and rotational speed (N(t)[k(rpm)]) of the DC motor for a pump without any additional sensors. In the proposed estimation method, two auto-regressive exogenous (ARX) models are employed. One ARX model has an output, P(t) or Q(t), and three inputs, VI(t) = V(t)I(t) and N(t) and the steady state gain (K) of the system from VI(t) to N(t). It can be assumed that K may include the information on viscosity of blood. The coefficient parameters of this ARX model are identified in an off-line fashion before implantation of the pump. After implantation, P(t) or Q(t) is estimated by the same ARX model with the already identified parameters. The other ARX model is used to identify Kon the basis of VI(t) and N(t) in an on-line fashion every time the viscosity of blood may change. In the experiment, a mock circulatory system consisting of a centrifugal pump and a reservoir with 37% glycerin or water was employed. The root mean square error between measured Q(t) and its estimate obtained from the proposed method was 1.66L/min. On the other hand, a different method based on a single ARX model with inputs of VI(t) and N(t), but without the additional input of K, yielded the corresponding estimation error of 2.22L/min. This means that the proposed method can reduce its estimation error by about 25% in comparison with a method that cannot cope with the change in blood viscosity.     

Chemoprevention of heterocyclic amine-induced mammary carcinogenesis in rats

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is one of the most prevalent carcinogenic heterocyclic amines in the environment, targeting the colon, prostate, pancreas, and mammary gland in rodents. Chemopreventive effects of synthetic and naturally occurring compounds on PhIP-induced rat mammary carcinogenesis were investigated in a series of experiments. In a PhIP feeding model, groups of 20-21 female F344 rats each, were treated with 0.02% PhIP alone or PhIP plus 0.5% 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), 1% green tea catechins, 1% alpha-tocopherol, 0.1% ellagic acid, or 1% chlorophyllin, each in the diet, or 0.1% caffeine in drinking water for 52 weeks. To assess the mechanism of HTHQ and caffeine inhibition of PhIP-induced carcinogenesis, effects of these compound on the in vitro metabolic activation of PhIP were examined in the presence of S9 mix. In the next series of experiments, the PhIP intragastric dose model was applied to allow separate investigation of the effects of chemicals during the initiation and postinitiation periods. In these experiments, female Sprague-Dawley rats were given eight intragastric doses of 100 mg/kg body weight during the first 4-8 weeks for initiation. Either during initiation or after initiation, or only after initiation, animals were treated with either corn or perilla oil at doses of 5 and 20%, conjugated fatty acid derived from safflower oil (CFA-S) or perilla oil (CFA-P) at a dose of 1%, arctiin at doses of 0.02 and 0.2% in the diet, or sodium nitrite (NaNO(2)) at a dose of 0.2% in drinking water. In the PhIP feeding model, administration of PhIP alone for 52 weeks induced adenocarcinomas in 40% of rats, but the incidence was remarkably reduced to 5% by the simultaneous treatment with 0.5% HTHQ, a strong lipophilic phenolic antioxidant, or to 10% by 0.1% caffeine. Administration of 1% chlorophyllin exerted similar, albeit weaker, effects. alpha-Tocopherol at a dose of 0.5% only reduced the multiplicity of carcinomas, and 1% green tea catechins only the mean size of mammary tumors. In a metabolic activation study of PhIP, HTHQ and caffeine clearly inhibited the formation of metabolites. In the PhIP gastric dose model, among the naturally occurring compounds examined, a plant lignan arctiin, perilla oil, which contains a large amount of n-6 alpha-linolenic acid, and CFA-S or CFA-P inhibited mammary tumor development, particularly in the postinitiation period, although a clear dose response was not observed. Treatment with 0.2% NaNO(2) in the initiation period was found to lower the volume of mammary tumors. The present results indicate that a number of compounds may be candidate chemopreventive agents against PhIP-induced mammary carcinogenesis, acting through different mechanisms and depending on the stage of carcinogenesis.     

Role of nectin in organization of tight junctions in epithelial cells

BACKGROUND: In polarized epithelial cells, cell-cell adhesion forms specialized membrane structures comprised of claudin-based tight junctions (TJs) and of E-cadherin-based adherens junctions (AJs). These structures are aligned from the apical to the basal side of the lateral membrane, but the mechanism of this organization remains unknown. Nectin is a Ca2+ independent immunoglobulin-like cell-cell adhesion molecule which localizes at AJs. Nectin is associated with E-cadherin through their respective cytoplasmic tail-binding proteins, afadin and catenins, and involved in the formation of AJs in cooperation with E-cadherin. We show here that nectin is also involved in the formation of TJs. RESULTS: During the formation of the junctional complex consisting of AJs and TJs in Madin-Darby canine kidney (MDCK) cells, claudin and occludin accumulated at the apical sites of the nectin-based cell-cell adhesion sites. This accumulation of claudin and occludin was inhibited by inhibitors acting on the trans interaction of nectin. The barrier function of TJs was also impaired by the nectin inhibitors. It has been shown that a phorbol ester promotes the formation of a TJ-like structure in an E-cadherin-independent manner. This phorbol ester-induced formation of the TJ-like structure was also inhibited by the nectin inhibitors. CONCLUSIONS: These results suggest a role of the nectin-afadin system in the organization of TJs as well as AJs in epithelial cells.     

Cdc42 and Rac small G proteins activated by trans-interactions of nectins are involved in activation of c-Jun N-terminal kinase,but not in association of nectins and cadherin to form adherens junctions,in fibroblasts

BACKGROUND: Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules which associate with cadherins to form adherens junctions (AJs) in epithelial cells and fibroblasts. Nectin-1 and -3 are members of the nectin family which most strongly trans-interact, causing cell-cell adhesion. The trans-interaction between nectin-1 and -3 induces the activation of both Cdc42 and Rac small G proteins in epithelial cells. We studied the roles of Cdc42 and Rac activated in this way in L fibroblasts stably expressing both nectin-1 and E-cadherin (nectin-1-EL cells). RESULTS: The trans-interaction between nectin-1 and -3 induced the activation of Cdc42 and Rac in nectin-1-EL cells. Cdc42, and presumably Rac, activated in this way, induced the activation of c-Jun N-terminal kinase (JNK), but not p38 mitogen-activated protein (MAP) kinase or extracellular signal-regulated kinase (ERK). Cdc42 or Rac was not essential for the association of nectin-1 and E-cadherin to form AJs. Reorganization of the actin cytoskeleton was not required for the association of nectin-1 and E-cadherin. CONCLUSION: These results indicate that Cdc42 and Rac activated by the trans-interaction of nectins selectively induce the activation of JNK, but are not essential for the association of nectins and cadherin to form AJs in fibroblasts.     

Survey of atopic dermatitis and skin barrier functions in Japanese and Chinese school students]

BACKGROUND: The comparative studies of the prevalence of atopic dermatitis and skin barrier functions in Japanese and Chinese were performed. METHODS: Clinical investigations were performed in 68 elementary school students in Lhasa, Tibet Autonomous Region and 67 students in Yixing, Jiangsu Province in China, and 99 students in Nishinomiya, Hyogo in Japan. Transepidermal water loss (TEWL) and capacitance were measured. Questionary survey about bathing frequency was also performed for students in Lhasa, Yixing and Osaka. RESULT: The prevalence rate of atopic dermatitis was 0% in Lhasa, 2.63% in Yixing, 4.26% in Nishinomiya. TEWL of students in Nishinomiya was higher than that in Yixing and Lhasa. Capacitance of students in Lhasa was lower than that in Nishinomiya and Yixing. The frequency of taking a bath in Lhasa was about 2.2 times per month and fewer than that in Nishinomiya and Yixing. CONCLUSION: There was tendency that the prevalence of atopic dermatitis increased according to increase of TEWL. It was thought that more investigations are necessary whether the development of habitat and environment influence the prevalence of atopic dermatitis and skin barrier function.     

Modifying effects of 1'-acetoxychavicol acetate (ACA) and the novel synthetic retinoids Re-80, Am-580 and Am-55P in a two-stage carcinogenesis model in female rats

Effects of dietary administration of 1'-acetoxychavicol acetate (ACA) and the novel synthetic retinoids 4-[1-hydroxy-3-oxo-3-(5,6,7,8-tetrahydro-3-hydroxy-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl]benzoic acid (Re-80); 4-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carboxamido]benzoic acid (Am-580); and 6-[(3,5-di-tert-butylphenyl) carbamoyl]nicotinic acid (Am-55P) were examined using a two-stage rat carcinogenesis model. A total of 190 female SD rats was treated sequentially with 1,2-dimethylhydrazine (DMH, s.c.); 7,12-dimethylbenz(a)anthracene (DMBA, i.g.); and 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN, in the drinking water) during the first three weeks (DDD-initiation), and an additional 60 rats received the vehicle alone (non-initiation). One week after the completion of the initiation period, they were divided into nine groups and administrated Re-80 (at dose levels of 1.0 or 0.4 ppm), Am-580 (20 or 4 ppm), Am-55P (20 ppm), ACA (100 ppm), all-trans-retinoic acid (10 or 2 ppm) or no supplement in the diet for 33 weeks, until survivors were euthanatized at week 37 weeks. After DDD-initiation, all-trans-retinoic acid at the high dose delayed the development of mammary tumors. The multiplicity of colon tumors in the group fed Am-55P and the incidences of nephroblastomas with ACA or Am-580 were decreased as compared with the control values, but the other chemicals had no modifying effects on tumor development in any organs. Thus, among ACA and the novel synthetic retinoids tested, only Am-55P showed a weak inhibitory effect on a neoplasm of general interest under the present experimental conditions.     

HTL V-I from Iranian Mashhadi Jews in Israel is phylogenetically related to that of Japan,India, and South America rather than to that of Africa and Melanesia

A new endemic focus of human T-lymphotropic virus type I (HTL V-I) was recently reported among Mashhadi Jews, a group of immigrants from northeastern Iran to Israel. We extracted DNAs from fresh peripheral blood mononuclear cells (PBMCs) and/or gargle mouthwash from 10 HTL V-I carriers, who consisted of members of one family, and HTL V-I-associated myelopathy (HAM) and adult T-cell leukemia (ATL) patients. Long terminal repeat (LTR) regions of proviral DNAs were sequenced and analyzed phylogenetically. In a phylogenetic tree, all the Mashhadi HTL V-I isolates belonged to subtype A, one of the three subtypes of the cosmopolitan type of HTL V-I, and made a tight cluster distinct from the other isolates of subtype A from Japan, India, the Caribbean Basin, and South America. Although a few nucleotide substitutions were observed among the clones sequenced, no characteristic sequence variation was found in different disease manifestations, even in one family or different sources of DNA preparation.     

Difference in antibody reactivity between complement fixation and immune adherence hemagglutination tests with virus antigens.

Complement-fixing (CF) immunoglobulin M antibody to infantile gastroenteritis virus (a rotavirus) did not show the reactivity of immune adherence hemagglutination (IAHA). Early immunoglobulin G CF antibody produced both in patients and in guinea pigs experimentally infected with Japanese encephalitis virus (a flavivirus) had weak reactivity in IAHA test. However, late antibody showed higher titers by IAHA than by CF. These results suggested that early antibodies with lower affinity are inefficient in the IAHA reaction. The implications of this study are: (i) a low ratio of IAHA/CF antibody titers in a serum suggests a recent rotavirus infection; (ii) the IAHA reaction is more type specific than the CF reaction for identifying the serotype of antigenically cross-reacting viruses with hyperimmune sera.