Cadaveric study of the nasal periosteum and implant position after augmentation rhinoplasty

Augmentation rhinoplasty is one of the most common cosmetic procedures done in Asia. A technique believed to be helpful in reducing complications is subperiosteal placement of silicone implant. A deeply placed implant should benefit from having thicker soft tissue coverage. Tough periosteal tissue is hoped to provide better implant fixation and prevent undesirable mobility. Experienced surgeons often claim that they can preserve the nasal periosteum and achieve complete implant coverage via nasal rim incision(s). However, success of implant placement and preservation of periosteal integrity after nasal augmentation has never been studied before.Nose augmentation with silicone implant was conducted in 12 fresh cadavers with the closed technique used in real practice. Open dissection of the nose was then carried out to verify implant position and the integrity of the periosteum. Factors that could affect the outcomes, including blade sizes of periosteal elevators, use of Aufricht retractor, and surgeon's experience, were analyzed.We found that all silicones could be implanted in the subperiosteal plane independent of instruments, surgeon's technique, and experience. Nonetheless, the covering nasal periosteum was always torn at its periphery and disconnected from the surrounding bone. As a result, lateral sides of the inserted silicones were not immediately covered with the periosteum.In conclusion, the surgeon's experience, the size of the periosteal elevator, and the Aufricht retractor did not affect the success of implant placement in the subperiosteal plane. Periosteal coverage was always incomplete and did not provide immediate implant fixation as previously understood.     

Effect of xylitol and fluoride on enamel erosion in vitro

This study aimed to determine the anti-erosive effects of xylitol, fluoride and a xylitol/fluoride combination used as an additive in an acidic drink or as mouthrinse after enamel was exposed to an acidic drink, in vitro. Human third molars were divided into 7 groups (A-G). Samples from groups A to D were immersed for 5 min in orange juice only (A), orange juice plus either 25% xylitol (B), F(-) 1 ppm (C) or a 25% xylitol/F(-) 1 ppm combination (D), respectively. Samples from groups E to G were immersed in orange juice for 5 min and then in either 40% xylitol (E), F(-) 227 ppm (F) or a 40% xylitol/F(-) 227 ppm combination (G), for 1 min respectively. This process was performed four times daily for 14 days. Mineral loss was determined from the lesion depth and surface hardness. Erosion depth progressively increased in all groups, except E, where erosion depth was significantly lower than group A. Surface microhardness progressively decreased in all groups, except E, where hardness was significantly higher than group A. This study demonstrated that addition of xylitol, fluoride or a xylitol/fluoride combination to an acidic drink or post-treatment with fluoride or a xylitol/fluoride combination could reduce, but not prevent, enamel erosion.     

Mucocutaneous findings in pediatric AIDS related to degree of immunosuppression

The normal value of the absolute CD4-positive T-lymphocyte count is relatively high in normal infants and declines steadily until 6 years of age, whereas the CD4 percentage of the total lymphocyte count is constant. The immunologic categories according to the 1994 revised pediatric human immunodeficiency virus (HIV) classification, based on CD4-positive percentage of the total lymphocyte count, is classified into three categories: no evidence of suppression (> or =25%), moderate suppression (15-24%), and severe suppression (1-14%). Our objective was to determine the prevalence of mucocutaneous findings in pediatric acquired immunodeficiency syndrome (AIDS) related to the degree of immunosuppression. We prospectively examined 120 children less than 13 years of age who were born to HIV-seropositive women and developed definite HIV infection. The prevalence of mucocutaneous findings in those children who had severe, moderate, and no evidence of immunosuppression were 62%, 43%, and 20%, respectively. The mucocutaneous findings in patients in the moderate and severe suppression groups were significantly more common than in patients without evidence of immunosuppression (p < 0.001). In the moderate immunosuppression group, 11% had two mucocutaneous findings while 21% in the severe immunosuppression group had two or more mucocutaneous findings. The most common mucocutaneous finding was oral candidiasis (33%), which had a mean corresponding CD4 percentage of the total lymphocyte count of 11.3%. Herpes zoster was found in 6% of the patients (mean CD4 percentage of the total lymphocyte count = 13.5%). Chronic herpes simplex virus (HSV) stomatitis was found in 3% of the patients (mean CD4 percentage of the total lymphocyte count = 3%). Mucocutaneous manifestations are common in pediatric AIDS. The majority of these findings have an infectious etiology. The prevalence increases as the CD4-positive percentage of the total lymphocyte count decreases. More than one mucocutaneous finding can be found at the same time in patients with moderate or severe immunosuppression.     

Hepatotoxic effect of (+)usnic acid from Usnea siamensis Wainio in rats, isolated rat hepatocytes and isolated rat liver mitochondria

Hepatotoxic effect of (+)usnic acid, the active constituent of Usnea siamensis Wainio was studied in rats, isolated rat hepatocytes and isolated rat liver mitochondria. In rats, after treatment with high dose of (+)usnic acid (200 mg/kg per day, i.p.) for 5 days, there was no significant change in serum transaminase activity (serum AST, ALT) while the electron micrographs showed apparent morphological damage of mitochondria and endoplasmic reticulum. (+)Usnic acid at high dose (1 mM) as well as carbon tetrachloride (CCl₄, the reference hepatotoxin) induced loss of cell membrane integrity in isolated rat hepatocytes by increasing the release of cellular transaminases (AST, ALT). Increase in lipid peroxidation, decrease in glutathione (GSH) content and increase in aniline hydroxylase activity (CYP 2E1) were also found. Combination of (+)usnic acid and CCl₄ showed the additive results. (+)Usnic acid (0.15–6 μM) possessed uncoupling activity in isolated rat liver mitochondria. It stimulated respiration by mitochondria respiring with glutamate plus malate or succinate as substrates and activated ATPase activity. Increasing concentration of (+)usnic acid (>6 μM) exhibited loss of respiratory control and ATP synthesis. In conclusion, hepatotoxic effect of high dose (+)usnic acid may involve its reactive metabolite(s), causing loss of integrity of membrane like structures, resulting in destruction of mitochondrial respiration and oxidative phosphorylation.     

Efficacy of pulsed dyed laser (585 nm) in the treatment of molluscum contagiosum subtype 1

Molluscum contagiosum is a common cutaneous disease that may be difficult to treat when there are multiple lesions; especially in children. This study was conducted to determine the efficacy of pulsed dye laser (585 nm) in the treatment of molluscum contagiosum in 20 children. In the treated group, 70.5% of lesions healed after the first treatment; the remaining 10.6% after the second treatment (2 weeks later). The overall cure rate was significantly different from the control group (p< 0.01). The therapy was also well tolerated. Only mild transient hypopigmentation and erythema were observed. None encountered infectious events. In conclusion, pulsed dye laser is a good alternative treatment for molluscum contagiosum due to high efficacy and mild transient side effects.     

Heterozygous nonsense mutation SATB2 associated with cleft palate, osteoporosis, and cognitive defects

Studies of human chromosomal aberrations and knockout (KO) mice have suggested SATB2 as a candidate gene for a human malformation syndrome of craniofacial patterning and brain development. Of 59 unrelated patients with craniofacial dysmorphism, with or without mental retardation, one 36-year-old man had a nonsynonymous mutation in SATB2. The affected individual exhibited craniofacial dysmorphisms including cleft palate, generalized osteoporosis, profound mental retardation, epilepsy and a jovial personality. He carries a de novo germline nonsense mutation (c.715C>T, p.R239X) in the exon 6 of SATB2. Expression studies showed that the mutant RNA was stable, expected to produce a truncated protein predicted to retain its dimerization domain and exert a dominant negative effect. This new syndrome is the first determined to result from mutation of a gene within the family that encodes nuclear matrix-attachment region (MAR) proteins.     

Revision of the Thai Red Cross intradermal rabies post-exposure regimen by eliminating the 90-day booster injection

The Thai Red Cross intradermal post-exposure rabies prophylaxis regimen (TRC-ID) is being used in Thailand, the Philippines, Sri Lanka and is making inroads in India. It consists of two injections of 0.1 mL of any World Health Organization recommended tissue culture rabies vaccine intradermally at two sites on days 0, 3, 7, followed by one injection on days 28 and 90. Two decades of experience had shown that approximately 11% of 187,000 possibly rabies exposed subjects who received the TRC-ID schedule, did not return for the 90-day booster. No rabies deaths had, however, been reported from this group. This stimulated two studies to determine whether the 90-day booster can be abolished. They demonstrated that, if the single 28-day 0.1 mL injection is increased to two at two sites, a comparable antibody response can be achieved and the 90-day booster can be omitted. The tissue culture rabies vaccine used in the preliminary study was purified chick embryo vaccine (PCEC Chiron) and for this study it was chromatography purified Vero cell vaccine (CPRV, Aventis-Pasteur). CPRV had been previously shown to be as immunogenic and effective as purified Vero cell rabies vaccine (PVRV).     

Malassezia furfur in infantile seborrheic dermatitis

Our objective was to study both incidence and various strains of Malassezia in infantile seborrheic dermatitis (ISD). Sixty infants between 2 weeks and 2 years old with clinical diagnosis of ISD at the Department of Pediatrics, King Chulalongkorn Memorial Hospital from May 2002 to April 2003 were recruited. Malassezia spp. were isolated from cultured skin samples of the patients, genomic DNA was extracted and the ITS1 rDNA region was amplified. The PCR product was examined by agarose gel electrophoresis and DNA sequences were determined. The ITS1 sequences were also subjected to phylogenetic analysis and species identification. ISD is most commonly found in infants below the age of 2 months (64%), followed by those between 2 and 4 months (28%) old. Cultures yielded yeast-like colonies in 15 specimens. PCR yielded 200-bp products (Candida) in 3 patients and 300-bp products (Malassezia furfur) in 12 patients (18%). Sugar fermentation using API 20C aux performed on the three 200-bp PCR products yielded Candida species. M. furfur was the only Malassezia recovered from skin scrapings of children with ISD.