Achlya sp. Dermatitis in an American Alligator (Alligator mississippiensis).

Oomycetes are water moulds in the kingdom Protista and are not considered true fungi due to the structural lack of chitin and ergosterol. Many oomycetes are pathogenic, such as Pythium spp., and many fish are prone to Saprolegnia spp. infections, particularly in stressful farming situations. A juvenile American alligator (Alligator mississippiensis) was presented for necropsy examination with white, gelatinous, raised lesions over ulcerated regions of skin on the limbs and tail. The alligator came from a hatchery with age-divided enclosures, and several of the animals within the same enclosure showed similar lesions. Numerous hyphae with non-parallel walls and sparse, non-dichotomous branching were observed histologically on Gomori's methenamine silver staining within the ulcers. Although no organisms were detectable via polymerase chain reaction testing of fresh or formalin-fixed tissues, the organism was cultured and sequenced as an Achlya sp., an infrequently identified oomycete. To the author's knowledge, this is the first description of an oomycete infection within the class Reptilia.

Pathological Internet use and associated factors among university students in Hong Kong.

1. Among university entrants, the prevalence of pathological Internet use (PIU) increased more than three-fold (from 5.0 to 15.7%) after 18 months of university life. Psycho-social factors such as depression, life dissatisfaction, and use of the Internet for recreational purposes were associated with the development of PIU. 2. University health workers should be aware that PIU is associated with inferior mental well-being, increased sleeping disorders, and deterioration of family relationships. Special attention should be given to Mainland Chinese students and those with pre-existing psychological problems, as they are more prone to developing PIU. 3. Most university students with PIU were unaware of the health implications of the condition and thus not motivated to seek help. Health workers must take a pro-active approach.

Exploring predictors influencing intended and actual acceptability of the A/H1N1 pandemic vaccine: a cohort study of university students in Hong Kong.

OBJECTIVES: To investigate the factors associated with the uptake of influenza A/H1N1 vaccination by university students, and to examine the relationship between intention and actual vaccination. STUDY DESIGN: Prospective cohort study. METHODS: A baseline survey was conducted among students at the Chinese University of Hong Kong in 2009 to collect data on demographics, pandemic risk perceptions and self-reported intention to be vaccinated in the future. A follow-up survey was conducted in 2011 using an online survey platform collecting information on actual vaccine uptake behaviour, and vaccine attitudes, knowledge and perceptions. RESULTS: Self-reported intention to be vaccinated in 2009 was significantly associated with actual vaccine acceptance. Vaccine perceptions (attitudes and knowledge) were found to be a better predictor of vaccine acceptance than disease risk perceptions. Being a medical or science student and receiving health advice about vaccination from a doctor or school-endorsed advertisement were also found to be predictors of vaccine acceptance. CONCLUSIONS: University students in Hong Kong were wary of the A/H1N1 vaccination campaign, as revealed by their low uptake rate and doubts about the vaccine. Knowledge of the pandemic and vaccine was high in this population, but feelings of susceptibility were low. The results indicate a need to provide tailored messages emphasizing the importance of vaccination and the efficacy of the vaccine in the future.

Brief report: Predictors of heavy Internet use and associations with health-promoting and health risk behaviors among Hong Kong university students.

To examine the correlates of heavy Internet use and determine the associations of heavy Internet use with various health risk behaviors and health-promoting behaviors among Chinese adolescents, an anonymous, self-administered health behavior questionnaire was completed by 2427 matriculants into a Hong Kong university (mean age=18.9 y) and returned at compulsory health examination. Of students, 14.8% reported heavy Internet use (>4h/day) and such use was associated with lower likelihood of engaging in health-promoting activities such as exercising and seeking medical care. At the same time, heavy Internet use was correlated with multiple risk behaviors such as skipping meals and sleeping late as well as poorer health outcomes such as higher likelihood of being overweight or having hypersomnia. Given the double burden of poorer health outcomes and fewer health-promoting behaviors, heavy Internet users represent a particularly challenging group for adolescent health promotion.

In vitro antidiabetic activities of five medicinal herbs used in Chinese medicinal formulae.

Fructus Corni, Fructus Schisandrae Chinensis, Poria, Rhizoma Alismatis and Rhizoma Dioscoreae are commonly used in traditional Chinese medicine for diabetes treatment. They are also the component herbs of an antidiabetic foot ulcer formula with demonstrated clinical efficacy. Although some of these herbal extracts were previously shown to possess in vivo antidiabetic effects (i.e. lowering blood glucose levels), the underlying mechanisms remain elusive. The objective of this study is to investigate the possible antidiabetic mechanisms of these individual herbs, using a systematic study platform which includes four in vitro tissue models: glucose absorption into intestinal brush border membrane vesicles (BBMV), gluconeogenesis by rat hepatoma cell line H4IIE, glucose uptake by human skin fibroblasts cell line Hs68 and mouse adipocytes 3T3-L1. All tested herbs showed significant in vitro antidiabetic effects in at least two models. Fructus Schisandrae Chinensis, Poria, Rhizoma Alismatis and Rhizoma Dioscoreae showed significant inhibitory effects in the BBMV glucose uptake assay. All tested herbs showed significant stimulatory effects to the glucose uptake of Hs68 and 3T3-L1 cells, except Poria and Rhizoma Dioscoreae which were not effective to Hs68 and 3T3-L1 respectively. However, none of the tested herbs inhibited hepatic gluconeogenesis. In conclusion, the five herbs exhibited distinct antidiabetic mechanisms in vitro and hence our investigations provided scientific evidence to support the traditional usage of these herbs for diabetic treatment in medicinal formulae.

An in vivo investigation on the wound-healing effect of two medicinal herbs using an animal model with foot ulcer.

BACKGROUND/AIM: Over 190 million people in the world suffer from diabetes mellitus. Diabetics are 25 times more likely to have a leg amputated because of unhealing foot ulcers. Herbal medicine has been used in China to salvage the ulcerated limb. With the aim to study the efficacy of two commonly used herbs for ulcer healing, namely Radix Astragali and Radix Rehmanniae, a good animal model needs to be developed for a proper in vivo investigation. METHODS: Firstly, a diabetic animal model was established by streptozotocin injection. Then standard wounds were created on the feet of the diabetic rats. Digital photographs were taken and analyzed by a novel image analysis software. RESULTS: The average ulcer area in the Radix Rehmanniae treatment group was 11.45 mm2, which was significantly smaller than the 15.12 mm2 in the water treatment group (p = 0.04). Radix Astragali, on the other hand, was found to have no significant effect on ulcer shrinkage. CONCLUSION: Further investigation is needed for the identification of the active principles of Radix Rehmanniae.

Ly49 C/I-dependent NKT cell-derived IL-10 is required for corneal graft survival and peripheral tolerance.

Similar to their activity on NK cells, Ly49 molecules play a pivotal role in influencing how NKT cells respond. It is known that Ly49 C/I is an inhibitory receptor capable of down-modulating proliferation, IFN-gamma response, and cytotoxic activity in cells that express it. In a model of peripheral tolerance induced via the eye, we observed that Ly49 C/I-positive, invariant NKT cells were required. To test if the NK inhibitory receptor functionally contributed to tolerance development, we used blocking antibody, in vivo and in vitro, to interfere with the development of antigen-specific suppression. A result of blocking ligation of Ly49 C/I inhibitory receptor prevented NKT cell production of IL-10 and the subsequent development of tolerance. Ly49 C/I-blocking antibodies also prevented corneal graft survival, a phenomenon dependent on eye-induced tolerance. Furthermore, in the presence of TCR stimulation, cross-linking of Ly49 C/I on CD4(+) NKT cells stimulated an increase in IL-10 mRNA and a decrease in IFN-gamma. The concept of Ly49 inhibitory receptors regulating immune reactivity to self by regulating immune activity of individual cells is thus expanded to include a role for the inhibitory receptors in the more global process of peripheral tolerance to foreign antigens.

Pharmacological investigations of the anti-diabetic effect of Cortex Moutan and its active component paeonol.

Cortex Moutan (CM, root bark of Paeonia suffruticosa Andr.) is one of the common herbs found in anti-diabetic traditional Chinese medicine formulae. To study the potential anti-diabetic mechanisms of CM, four in vitro models (intestinal brush border membrane vesicles (BBMV), rat hepatoma cell line H4IIE, human skin fibroblasts cell line Hs68 and mouse adipocytes 3T3-L1) were used. CM showed significant in vitro anti-diabetic effects by inhibiting glucose uptake of BBMV and enhancing glucose uptake into Hs68 and 3T3-L1 cells. Using bioassay-guided fractionation, paeonol was confirmed to be one of the active constituents for inhibiting BBMV glucose uptake. With neonatal-streptozotocin diabetic rats, paeonol (200 and 400mg/kgbody wt.) was found to improve oral glucose tolerance in vivo. To the best of our knowledge, this is the first report on the anti-diabetic effect of paeonol.

Influence of an anti-diabetic foot ulcer formula and its component herbs on tissue and systemic glucose homeostasis.

Complications of diabetes impose major public health burdens worldwide. The positive effect of a Radix Astragali-based herbal preparation on healing diabetic foot ulcers in patients has been reported. Formula 1 is also referred as the 'Herbal drink to strengthen muscle and control swelling'. This formula contains six Chinese medical herbs, including Radix Astragali, Radix Rehmanniae, Rhizoma Smilacis Chinensis, Rhizoma Atractylodis Macrocephalae, Radix Polygoni Multiflori Preparata, and Radix Stephania Tetrandrae. Three of these herbs (Radix Astragali, Radix Rehmanniae, Rhizoma Atractylodis Macrocephalae) are commonly used in different anti-diabetic formulae of Chinese medicine. The objective of the current study is to use an interdisciplinary approach to test the hypothesis that Formula 1 and its components influence tissue and systemic glucose homeostasis. In vitro and in vivo models have been established including: (1) glucose absorption into intestinal brush border membrane vesicles (BBMV); (2) gluconeogenesis by H4IIE hepatoma cells; (3) glucose uptake by 3T3-L1 adipocytes and Hs68 skin fibroblasts; (4) normalization of glycaemic control in a diabetic rat model. The results of in vitro studies indicated that all herbal extracts can modify cellular glucose homeostasis. Since Formula 1 and Rhizoma Smilacis Chinensis extracts demonstrated potent effects on modifying glucose homeostasis in multiple tissues in vitro, they were further studied for their anti-diabetic activities in vivo using a streptozotocin (STZ)-induced diabetic rat model. The results showed that Formula 1 and Rhizoma Smilacis Chinensis extracts did not significantly improve oral glucose tolerance or basal glycaemia in diabetic rats. In conclusion, the anti-diabetic foot ulcer Formula 1 contains ingredients active in modifying tissue glucose homeostasis in vitro but these biological activities could not be associated with improved glycaemic control of diabetes in vivo.

Intracellular T lymphocyte cytokine profiles in the aqueous humour of patients with uveitis and correlation with clinical phenotype.

This study aimed to investigate whether T cells in aqueous humour are different in different types of uveitis and correlate with clinical phenotype. Patients with clinically different types of uveitis, but all displaying active anterior uveitis, were phenotyped and samples of aqueous humour (AH) and peripheral blood (PB) collected. Cells from AH and PB were separated by centrifugation and by density gradient centrifugation (to obtain mononuclear cells PBMC), respectively. Cells were activated with PMA and ionomycin in the presence of Brefeldin A, stained for surface markers and intracellular cytokines, and analysed by flow cytometry. The cytokine profile was correlated with the clinical phenotype. Increased percentages of interleukin (IL)-10+-, but not interferon (IFN)-gamma+ T lymphocytes were found in AH compared with PB in patients with acute anterior uveitis (AAU), FHC or chronic panuveitis (PU). There was a trend towards elevated levels of IL-10+ T cells in AH from patients with FHC compared with AH from acute uveitis and panuveitis patients. Increased levels of IL-10+ T cells in AH compared with PB were also found in samples from patients with isolated uveitis, but not those with associated systemic disease. Levels of cytokine-positive T cells were not associated with the use of topical steroids or to the severity of the anterior uveitis. While type I cytokine-producing T lymphocytes are present in AH during AU, the presence of increased proportions of IL-10+ T lymphocytes in AH from patients with uveitis may be indicative of an anti-inflammatory mechanism that may influence the type and course of ocular inflammation in these patients.

Development and evaluation of a new composite Laserskin graft.

BACKGROUND: Tremendous effort has been made to improve the graft take rate of cultured epidermal autograph. The purpose of this study is to develop and evaluate a new composite Laserskin graft (CLSG) as a human skin substitute for wound resurfacing. METHODS: The seeding efficacy of cultured keratinocytes on plain Laserskin was compared with the 3T3 cell-seeded Laserskin and allogenic fibroblast-populated Laserskin. Three different types of CLSG, 2 cm in diameter each, were prepared and tested in rats. Type A CLSG consisted of proliferative allogenic rat fibroblasts on both sides of the Laserskin with autologous keratinocytes also on the upper side. Fibroblasts and keratinocytes were seeded only on the upper side of the Laserskin in type B CLSG. Keratinocytes alone were seeded on plain Laserskin in type C CLSG. Type B CLSG consisting of autologous keratinocytes and autologous dermal fibroblasts was tested on five selected wounds (5x5 cm each) of a patient with full-thickness burn. In another burn patient, type B CLSG consisting of autologous keratinocytes and allogenic dermal fibroblasts was grafted onto three wounds (5x5 cm each). RESULTS: The seeding efficacy of human keratinocytes on plain Laserskin increased from 75% to 95% when proliferative allogenic fibroblasts were grown as a feeder layer on the Laserskin. The seeding efficacy of rat keratinocytes increased from 36% to 88% in the presence of a proliferative allogenic fibroblast feeder layer, whereas human/rat keratinocytes had respective seeding efficacy of 98%/91% on Laserskin preseeded with mitomycin C-treated 3T3 cells. Skin biopsies of grafted type A CLSG on day 14 after grafting showed complete epithelialization without severe inflammation in 16 of 20 (80%) grafted surgical wounds in rats. There were eight (40%) and seven (35%) "takes" of the CLSG in types B and C, respectively. The infection rate in type B CLSG was two (10%). There was one (5%) infection in types A and C. The respective take rates on the two patients grafted with type B CLSG were 60% and 100%. CONCLUSION: The animal experiment and the preliminary clinical data showed that the CSLGs consisting of autologous keratinocytes and of autologous/allogenic fibroblasts are good human skin substitutes in terms of durability, biocompatibility, high seeding efficacy for keratinocytes, high graft take rate, and low infection rate.

The efficacy of collagen dermis membrane and fibrin on cultured epidermal graft using an athymic mouse model.

A human skin substitute consisting of human cultured keratinocytes, collagen dermis, and fibrin was evaluated in athymic mice. Eighty athymic mice were divided randomly into four groups. A 1.5x1.5-cm full-thickness wound defect was created on the back of each athymic mouse under anesthesia. These wounds were covered by sheets of cultured epidermal graft (group A), cultured epidermal graft with collagen dermis and fibrin (group B), cultured epidermal graft with collagen dermis (group C), or cultured epidermal graft with fibrin (group D). The grafts were secured and kept moist by specially designed saline gauze chambers. The take rates of the cultured graft with more than 50% of the wound covered were 65%, 15%, 50%, and 45% respectively. Group B had a significantly lower graft take rate, however the difference was not significant among groups A, C, and D. Light microscopy of biopsies of the grafted sites at 12 days showed complete epithelialization. The incidence of discharge from wound beds in groups A, B, C, and D was 0%, 15%, 15%, and 10% respectively. The results suggest that cultured cells are best grafted directly onto the wound bed or in combination with either a thin layer of collagen or fibrin but not both because the collagen dermal membrane and the fibrin together may impose too great a diffusion barrier for the cultured cell graft to become vascularized.

Trinucleotide CGG repeat in the FMR1 gene in Chinese mentally retarded patients.

The fragile X syndrome of mental retardation is related to the number of trinucleotide CGG repeats at the 5'-untranslated region of the FMR1 gene located on the X-chromosome. We have studied X-chromosomes from 649 unaffected Chinese subjects and 324 patients with mild mental retardation. All study subjects were unrelated. The CGG repeat number was analysed by electrophoresis of a polymerase chain reaction followed by gel transfer and hybridisation with a 32P-labeled (CCG)5 probe. The DNA samples having detectable CGG expansion were further analysed by Southern blot analysis with probe StB12.3 after restriction digestion by EcoR I and Eag I. For the unaffected Chinese subjects, a different distribution pattern of CGG allele size from Caucasians was observed. It was a bimodal pattern and the CGG repeat number ranged from 19 to 54. The most common CGG repeat allele was 29 compared with 30 in Caucasians. The second mode appeared at 36 repeats. There was mild statistical difference in the repeat patterns between the mentally retarded patients and unaffected subjects, although the essential features were similar. Among the mentally retarded patients, one male had an unmethylated full mutation and one female had a full mutation. The fragile X prevalence was 0.6%, which is lower than two previous studies in Chinese mentally retarded patients utilising cytogenetic analysis. Our results indicate that a large-scale screening program would be worthwhile to determine the prevalence of the fragile X syndrome in the Chinese population.