Ecological surveys of the Cryptococcus species complex in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Despite recent reports on the molecular epidemiology of cryptococcal infections in China, clinical isolates have been mostly reported from human immunodeficiency virus (HIV)-negative patients, and environmental isolates from China have rarely been included. The aim of this study was to investigate the ecological profile of Cryptococcus (C.) neoformans and C. gattii in China.</p><p><b>METHODS</b>A survey was performed in 10 cities from 20°N (North latitude) to 50°N and in a Eucalyptus (E.) camaldulensis forestry farm at the Guixi forestry center, China.</p><p><b>RESULTS</b>Six hundred and twenty samples of pigeon droppings from 10 cities and 819 E. camaldulensis tree samples were collected and inoculated on caffeic acid cornmeal agar (CACA). The brown-colored colonies were recultured to observe their morphology, growth on canavanine-glycine-bromothymol-blue (CGB) medium, phenol oxidase and urease activities, serotype and mating type. There were obvious differences in the positive sample rates of C. neoformans in pigeon droppings collected from the different cities, ranging from 50% in the cities located at latitudes from 30°N - 40°N, 29% at 20°N - 30°N and 13% at 40°N - 50°N.</p><p><b>CONCLUSIONS</b>There were no differences in positive bevy rates (approximately 80%) among the three grouped cities. Mycological tests of 101 isolates purified from pigeon droppings revealed that they were C. neoformans var. grubii. We also observed variable capsular size around the C. neoformans cells in colonies with variable melanin production and the bio-adhesion of the natural C. neoformans cells with other microorganisms. One urease-negative C. neoformans isolate was isolated from pigeon droppings in Jinan city. No C. gattii was isolated in this study.</p>

Effect of phospholipomannan of Candida albicans on the production of interleukin 6 and interleukin 8 in monocytes / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate whether Candida albicans-native phospholipomannan (PLM) induce an inflammation response through Toll-like receptor(TLRé2 in human acute monocytic leukemia cell line (THP-1) cells.</p><p><b>METHODS</b>Human THP-1 monocytes were challenged with PLM in vitro. The mRNA expressions of TLR2, TLR4, proinflammatory cytokine [interleukin(IL)-6], and chemokine (IL-8) were assayed by real time reverse transcription polymerase chain reaction. The secretions of IL-6 and IL-8 were measured by enzyme-linked immunosorbent assay. The expression of TLR2 was analyzed with Western blot.</p><p><b>RESULTS</b>PLM increased the mRNA expressions and secretions of proinflammatory cytokines (IL-6) and chemokines (IL-8) in THP-1 cells (all P=0.0000). PLM up-regulated the mRNA and protein levels of TLR2 (P=0.0000), whereas the mRNA level of TLR4 was not altered. PLM hydrolyzed with β-D-mannoside manno hydrolase failed to induce gene and protein expressions of TLR2, IL-6, and IL-8. Anti-TLRS-neutralizing antibody blocked the PLM-induced secretions of IL-6 and IL-8 in THP-1 cells (P = 0.0003, P = 0.0010).</p><p><b>CONCLUSION</b>Canidada albicans-native PLM may contribute to the inflammatory responses during Candida infection in a TLR2-dependent manner.</p>

Insoluble beta-glucan from the cell wall of Candida albicans induces immune responses of human THP-1 monocytes through Dectin-1 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>beta-glucan is the major structure component of Candida albicans (C. albicans) cell wall. It has been demonstrated that Dectin-1 as the principal C-type lectin pattern-recognition receptor (PRR) can recognize fungal beta-glucan and induce immune responses. In this study, we sought to clarify whether insoluble beta-glucan from the cell wall of C. albicans (CaIG) could induce immune responses in human THP-1 monocytes (a human acute monocytic leukemia cell line) and to determine the underlying mechanisms.</p><p><b>METHODS</b>Human THP-1 monocytes were challenged with CaIG in vitro. The mRNA expression of Dectin-1, Toll-like receptors (TLR2), proinflammatory cytokine (TNF-alpha) and chemokine (IL-8) was assayed by real-time reverse transcription polymerase chain reaction (RT-PCR). The secretion of TNF-a and IL-8 were measured by enzyme-linked immunosorbent assay (ELISA). H(2)O(2) release was determined by microplate fluorescent assay. Western blotting was used to analyze IkappaB-a phosphorylation and degradation.</p><p><b>RESULTS</b>Exposure of THP-1 monocytes to CaIG led to increased gene expression and secretion of TNF-alpha and IL-8. CaIG induced H(2)O(2) release in a time-dependent manner. CaIG hydrolyzed with zymolyase failed to induce gene expression and secretion of TNF-alpha, IL-8 and H(2)O(2) release. CaIG up-regulated the mRNA of Dectin-1, whereas the mRNA level of TLR2 was not altered. THP-1 monocytes challenged with CaIG resulted in the activation of NF-kappaB in a time-dependent manner. Dectin-1 inhibitor laminarin blocked the CaIG-induced production of TNF-alpha and H(2)O(2) in THP-1 monocytes, but no such effect was observed in pretreatment with anti-TLR2 neutralizing antibody and the LPS inhibitor (polymyxin B).</p><p><b>CONCLUSION</b>CaIG may play a role in activation of immune responses in human THP-1 cells through Dectin-1, not TLR2.</p>

Establishing an experimental guinea pig model of dermatophytosis Using Trichophyton rubrum / 中国医学科学院学报

<p><b>OBJECTIVE</b>To construct an animal model infected by Trichophyton rubrum.</p><p><b>METHODS</b>Three different strains of Trichophyton rubrum were separated from clinical specimen for the infection of guinea pigs. Corticosteroids were given before and after the construction of animal model to facilitate the infection. Direct microscopy, culture, and histopathologic methods were adopted to verify the construction.</p><p><b>RESULTS</b>Ten days after the inoculation of Trichophyton rubrum, with the intervention of corticosteroid, the guinea pigs were examined. Prominent scales and inflammation could be seen on the inoculation site of the Trichophyton rubrum infected guinea pig. Scales and hairs of Trichophyton rubrum infected guinea pig dealt with 10% potassium hydroxide, hypha out of the hair and microconidia or hypha in the hair shaft could be seen. Seven days after the inoculation of scales and hair on SDA plate, cultures of Trichophyton rubrum showed that the colonial morphology were identical to the original dermatophytes. PAS staining of infected guinea pig skin tissue showed that hypha and microconidia could be seen in the infundibula and hair root.</p><p><b>CONCLUSION</b>With the intervention of corticosteroid, a stable guinea pig model infected by Trichophyton rubrum were successfully constructed.</p>

Genotype comparisons of strains of Candida albicans from patients with cutaneous candidiasis and vaginal candidiasis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>It is uncertain whether genotypes of Candida albicans (C. albicans) are associated with colonizing body locations or variant conditions of infection. The aim of this study was to investigate whether there are significant associations between strain genotypes and body sites of infection and to determine the potential pathogenesis of cutaneous candidiasis at multiple locations.</p><p><b>METHODS</b>A total of 151 strains of C. albicans were isolated from 74 infant patients with cutaneous candidiasis and 61 female patients with vaginal candidiasis. Patients were grouped according to the body sites and underlying conditions of infection. Genotypes were identified by polymerase chain reaction (PCR) of the 25S rDNA and PCR-restriction fragment length polymorphism (RFLP) of ALT repeats digested with EcoRI and Clal.</p><p><b>RESULTS</b>Ten genotypes were detected. There were significant differences in genotype frequencies between the two groups. However, we found no clear association between genotypes and the sites of cutaneous infection or the underlying conditions of vaginal candidiasis (VVC). In addition, strains of C. albicans from multiple cutaneous locations of the same patient had identical genotypes.</p><p><b>CONCLUSIONS</b>Populations of C. albicans from patients with cutaneous and vaginal candidiasis were genetically different. However, the lack of genetic difference between strains from different body sites with cutaneous infections or from different underlying conditions for VVC suggests no evidence of genotype selection for different skin surfaces or patients with different underlying conditions for VVC.</p>

Effects of Malassezia isolates on cytokines production associated with melanogenesis by keratinocytes / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the co-culture of keratinocytes with Malassezia isolates which cause the pityriasis versicolor with different color and to analyze the changes of cytokines associated with melanogenesis.</p><p><b>METHODS</b>The effects of Malassezia species with different proportions on the growth rate of keratinocytes was assessed with 5 g/L methyl thiazolyl tetrazolium (MTT). Co-culture of keratinocytes and Malassezia species were performed with isolates from hyer- and hypo-pigmentation areas of pityriasis versicolor. The supernatants were collected at different time points, and the changes of basic fibroblast growth factor (b-FGF), endothelin-1 (ET-1), nerve growth factor-beta (NGF-beta), interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), stem cell factor (SCF) were recorded. Three control groups were established accordingly.</p><p><b>RESULTS</b>When the ratio between keratinocytes and Malassezia species was lower than 1: 10, the growth rate of keratinocytes was not affected by Malassezia (P > 0.05). When the ratio was increased above 1:20, the growth rate of keratinocytes was significantly inhibited by Malassezia (P < 0.01). The secretions of IL-1alpha, IL-6, TNF-alpha, and ET-1 was significantly increased after the co-culture of keratinocytes and Malassezia (P < 0.01), while those of b-FGF, NGF-beta, and SCF had no significant changes (P > 0.05). Compared with the isolates from the hypo-pigmentation area, ET-1 induced by isolate from hyperpigmentation area significantly increased (P < 0.01).</p><p><b>CONCLUSION</b>When Malassezia isolates are co-cultured with keratinocytes, the secretions of cytokines associated with melanogenesis may differ from each other. ET-1 may play certain role in the hyper-pigmentation of pityriasis versicolor.</p>

Effect of Metformin Therapy on Obese Nondiabetic Children with Hyperinsulinemia / 实用儿科临床杂志

Objective To explore the efficacy and safety of metformin therapy on obese nondiabetic children with hyperinsulinemia.Methods Twenty-two obese nondiabetic children with hyperinsulinemia were divided into two groups:control group(dietary counseling and exercise) and treatment group(dietary counseling and exercise combined with metformin).The changes of body mass index(BMI),fasting glucose(FPG),fasting insulin(FINS),insulin resistance(HOMA-IR),2 h PG,2 h INS,total cholesterol(TC) and triglyceride(TG),before and after treatment were determined,and the findings were compared and analyzed.Results After treatment,there were significant differences in BMI,TC,FINS,HOMA-IR levels(P0.05),except the BMI(P

COMPARISON OF GUIZOTIA ABYSSINICA SEED AGAR WITH CAFFEIC ACID CORNMEAL AGAR TO SELECTIVELY ISOLATE CRYPTOCOCCUS NEOFORMANS / 微生物学通报

The two verities of Crgptococcus neoforinans were first observed as well growing with brown color changes on Guizotia abyssinica seed agar(GASA)and caffeic acid commeal agar(CACA.Then,C.neoformans var.neoformans was found in 18/26 pigeon droppings by both two media.C.neoformans var.gattii was not isolated by the two media in 76 Eucalyptus camaldulensis samples.However,an,overgrowth of filamentous fungus was more frequently seen on GASA.Our results suggest that CACA be capable of selevtively isolating C.neoformans with the advantages of less interference fron the overgrowth of filamentous fungi.