Objective To examine the distribution of Malassezia species in follicular contents and perifollicular superficial skin in patients with Malassezia folliculitis and search for its causative agent. Methods A total of 120 patients with Malassezia folliculitis were investigated. Follicular lesions at three different anatomic sites were selected in each patient. Perifolliclar superficial skin specimens were taken by sterile adhesive tape, and the follicular contents of the same follicle were taken by sterile haemostatic forceps. The above specimens were cultured respectively on media containing rapeseed oil. The isolated colonies were identified by their physiological and morphological characteristics. Results Out of 319 isolates obtained from the perifollicular superficial skin, 247 isolates (77.43%) were identified as M. sympodialis, 40 isolates (12.54%) as M. furfur, 27 isolates(8.46%) as M. globosa and 5 isolates(1.57%) as M. obtusa. Out of 314 isolates obtained from follicular contents, 252 isdates(80.25%) were identified as M. globosa, 57 isolates(18.15%) as M. sympodialis, 4 isolates(1.27%) as M. furfur, and 1 isolate(0.32%) as M. obtusa. There was statistical difference in species distribution between the follicular contents and the perifolliclar superficial skin (P

Recently, plasma sterilization has attracted increasing attention in dental community for the atmospheric pressure non-equilibrium plasma jet (APNPs), which is driven by a kilohertz pulsed DC power, may be applied to the dental and oral diseases. However, it is still in doubt whether APNPs can effectively kill pathogenic bacteria in the oral cavity and produce no harmful effects on normal oral tissues, especially on normal mucosa. The aim of this study was to evaluate the bacterial-killing effect of APNPs in the biofilms containing a single breed of bacteria (Porphyromonas gingivalis, P.g.), and the pathological changes of the oral mucosa after treatment by APNPs. P.g. was incubated to form the biofilms in vitro, and the samples were divided into three groups randomly: group A (blank control); group B in which the biofilms were treated by APNPs (the setting of the equipment: 10 kHz, 1600 ns and 8 kV); group C in which the biofilms were exposed only to a gas jet without ignition of the plasma. Each group had three samples and each sample was processed for up to 5 min. The biofilms were then fluorescently stained, observed and photographed under a laser scanning confocal microscope. In the animal experiment, six male Japanese white rabbits were divided into two groups randomly (n=3 in each group) in terms of the different post-treatment time (1-day group and 5-day group). The buccal mucosa of the left side and the mucosa of the ventral surface of the tongue were treated by APNPs for 10 min in the same way as the bacterial biofilm experiment in each rabbit, and the corresponding mucosa of the other sides served as normal control. The clinical manifestations of the oral mucosa were observed and recorded every day. The rabbits were sacrificed one or five day(s) after APNPs treatment. The oral mucosa were harvested and prepared to haematoxylin and eosin-stained sections. Clinical observation and histopathological scores were used to assess mucosal changes. The results showed the obvious P.g. biofilms were formed at 10 days, and most of the bacteria in groups A and C were alive under a laser scanning confocal microscope, but the bacteria in the group B were almost all dead. In animal experiment, no ulcers, anabrosis and oral mucositis were found in both the 1-day and 5-day groups. The average mucous membrane irritation index was -0.83 and -0.67 in the 1-day and 5-day groups, respectively, suggesting that no intense mucosal membrane irritation responses occurred. It was concluded that APNPs could effectively kill P.g. in the biofilms and did not cause any pathological changes in the normal mucosa, suggesting that the plasma jet (APNPs) may be applied to oral diseases as a novel sterilization device in the future.

In order to find the linear region of adjustment process about human body balance under the passive movement, and provide the basis for the unified evaluation criteria of passive balance test, an equipment was built with pulsed excitation source and wave detector of gravity's center. The pulsed excitation source was a multi-dimensional motion platform with high accuracy. The wave detector was a force platform. Human body and force platform were treated as a whole object, and the dynamic model of the object was built using the method of system identification. The balance ability was evaluated by setting time. In the pulse excitement range from 2mm to 20 mm with 2mm increments, balance ability of 5 students was evaluated and analyzed respectively. Results showed that response curve of human balance regulation was a typical second order linear system characteristic, and in a large enough linear region, the evaluating result had good consistency.
Algorithms ; Equipment Design ; Female ; Humans ; Linear Models ; Male ; Movement ; Postural Balance ; physiology ; Young Adult

Recently,plasma sterilization has attracted increasing attention in dental community for the atmospheric pressure non-equilibrium plasma jet (APNPs),which is driven by a kilohertz pulsed DC power,may be applied to the dental and oral diseases.However,it is still in doubt whether APNPs can effectively kill pathogenic bacteria in the oral cavity and produce no harmful effects on normal oral tissues,especially on normal mucosa.The aim of this study was to evaluate the bacterial-killing effect of APNPs in the biofilms containing a single breed of bacteria (Porphyromonas gingivalis,Pg.),and the pathological changes of the oral mucosa after treatment by APNPs.Pg.was incubated to form the biofilms in vitro,and the samples were divided into three groups randomly:group A (blank control);group B in which the biofilms were treated by APNPs (the setting of the equipment:10 kHz,1600 ns and 8 kV); group C in which the biofilms were exposed only to a gas jet without ignition of the plasma.Each group had three samples and each sample was processed for up to 5 min.The biofilms were then fluorescently stained,observed and photographed under a laser scanning confocal microscope.In the animal experiment,six male Japanese white rabbits were divided into two groups randomly (n=3 in each group) in terms of the different post-treatment time (1-day group and 5-day group).The buccal mucosa of the left side and the mucosa of the ventral surface of the tongue were treated by APNPs for 10 min in the same way as the bacterial biofilm experiment in each rabbit,and the corresponding mucosa of the other sides served as normal control.The clinical manifestations of the oral mucosa were observed and recorded every day.The rabbits were sacrificed one or five day(s) after APNPs treatment.The oral mucosa were harvested and prepared to haematoxylin and eosin-stained sections.Clinical observation and histopathological scores were used to assess mucosal changes.The results showed the obvious P.g.biofilms were formed at 10 days,and most of the bacteria in groups A and C were alive under a laser scanning confocal microscope,but the bacteria in the group B were almost all dead.In animal experiment,no ulcers,anabrosis and oral mucositis were found in both the 1-day and 5-day groups.The average mucous membrane irritation index was -0.83 and -0.67 in the 1-day and 5-day groups,respectively,suggesting that no intense mucosal membrane irritation responses occurred.It was concluded that APNPs could effectively kill P.g.in the biofilms and did not cause any pathological changes in the normal mucosa,suggesting that the plasma jet (APNPs) may be applied to oral diseases as a novel sterilization device in the future.