Hypoxia promotes the formation of Cryptococcus neoformans biofilms / 医学研究生学报

Objective There is a lack of information on the effect of hypoxia on the virulence of Cryptococcus neoformans . This study was to construct a Cryptococcus neoformans bilfilm model in vitro and observe the influence of hypoxia on the biofilm forma-tion. Methods We constructed a Cryptococcus neoformans biofilm model in vitro in 24-well and 96-well microculture plates using DMEM culture medium at the oxygen concentrations of 21%( normoxia ) and 1% ( hypoxia ) .We collected the Cryptococcus neofor-mans biofilms at 2, 4, 8, 12, 24, 48, and 72 hours after culturing and observed their thickness , structure, and growth activity in the two different oxygen conditions by light microscopy , confocal laser scanning microscopy , and MTT assay . Results The Cryptococcus neoformans biofilm model was successfully constructed in the conditions of both hypoxia and normoxia .The processes of biofilm forma-tion in the two conditions were similar , involving adhesion , aggregation , micro-colony formation , and biofilm maturation , with the ulti-mate biofilm thickness of about 16 μm.The cell density and growth activity of the biofilms increased with the extension of incubation time, gradually stabilized with their maturity , and both were relatively higher at 1%than at 21%oxygen concentration . Conclusion The abilities of Cryptococcus neoformans biofilm formation vary with different oxygen concentrations , and hypoxia can promote the for-mation of Cryptococcus neoformans biofilms .

Multiple Segmental Eccrine Spiradenoma with a Zosteriform Pattern: A Case Report and Literature Review

Eccrine spiradenoma usually occurs as solitary tender nodules. However, it rarely occurs as multifocal localized tumors or has zosteriform distribution. We report the case of a 32-year-old woman with a 20-year history of itchy lesions on the left side of the back and forearm with a zosteriform distribution. Before disease onset, almost no patients have inducing factors, but our patient received an injection beforehand; however, whether this was coincidental or causative remains unknown. The lesions became very itchy after perspiration or eating spicy food, which has never been reported. A literature search revealed 22 cases of multiple segmental eccrine spiradenoma; we summarized the clinical characteristic in order to aid diagnosis and treatment selection.

Clinical analysis on chronically recurrent and generalized superficial mycosis caused by trichophyton rubrum / 医学研究生学报

Objective There have been a few reports on chronically recurrent and generalized superficial mycosis caused by trichophyton rubrum.This article was to investigate the cause, diagnosis and therapy of the mycosis. Methods 5 patients with chron-ically recurrent and generalized superficial mycosis caused by trichophyton rubrum were collected from June 2012 to June 2014 in our hospital.Bacterioscopic examination and cultivation were made on skin lesions of the patients.A typical patient who had 7-year course of desease with toenails seriously infected and widespread skin eruption was selected for histopathology examination on skin lesions, mi-crobiology and molecular biology study on 4 bacterial strains isolated from skin lesions in different parts, and in vitro chemosensitivity assay for drug selection.PCR (rDNA ITS sequence analysis) was performed for diagnosis and early treatment. Results Microscopic examintion on skin lesions demonstrated numerous septate, branched hyphae.Cultivation and molecular biology study identified tricho-phyton rubrum.The strain was identified as trichophyton rubrum by ITS sequence analysis and the isolated strains from different lesions were the same fungal species.Histopathology examination revealed slight hyperplasia of squamous epithelium , epidermal hyperkeratini-zation and the upper dermis presented a sparse perivascular lymphocytic infiltrate.The PAS-stain confirmed the presence of few hyphae in the horny layer.The pathogen of this case was trichophyton rubrum. A combination therapy with systemic itraconazole and topically applied terbinafine hydrochloride cream was successful.A follow-up examina-tion one year later showed no recurrence of symptoms. Conclusion The isolation and identification of pathogen is the key to the diagnosis of chronically recurrent and generalized superficial mycosis, with ad-ditional attention to all or none toenail infection.The therapy should not focus simply on the tinea corporis, while comprehensive treatment combined with chemosensitivity assay is preferred.

Membrane potential properties in the smooth muscle cells of middle cerebral artery in stroke-prone spontaneously hypertensive rats / 中国组织工程研究

BACKGROUND: The small change of the membrane potential (Em) of vascular smooth muscle cells (VSMC) could result in significant alteration in tension, and the membrane depolarization was closely associated with the development of hypertension.OBJECTIVE: To study the resting Em of VSMC from the middle cerebral artery (MCA) of stroke-prone spontaneously hypertensive rats (SHRSP) and the reactivity of Em to KCl and norepinephrine (NE).DESIGN: An animal experiment of comparative analysis.SETTING: Institute of Materia Medica, Shandong Academy of Medical Sciences.MATERIALS: Eighteen male SHRSP and 26 male Wistar rats were used.METHODS: ① Rats in both groups were anesthetized with intraperitoneal injection of ethyl carbamate (1 g/kg), the brains were removed quickly, and the Em of VSMC was recorded by intracellular microelectrodes. ② The effects of different concentrations of KC1 (10, 20, 50 mmol/L) and NE (10-7,10-6, 10-5 mol/L) on the Em of VSMC were observed.MAIN OUTCOME MEASURES: ① Em of VSMC in both groups; ②Effects of different concentrations of KC1 and NE on the Em of VSMC.RESULTS: ① The Em was obviously lower in SHRSP than in the Wistar rats [(-48.2±3.1), (-64.4±4.3) mV]. ② Both KC1 (10, 20, 50 mmol/L)and NE (10-7, 10-6, 10-5 mol/L) could cause the depolarization of Em of MCA in a concentration-dependent manner. The reactivity to MCA of SHRSP was obviously increased as compared with the Wistar rats.CONCLUSION: The resting Em of VSMC from the MCA of SHRSP was lower, and the reactivity of VSMC to KCl and NE was significantly stronger than that of Wistar rats.