Relationship between tinnitus loudness level and internal jugular venous flow rate measured by coloured Doppler ultrasonography in patients with a high jugular bulb

The aim of this study was to investigate the relationship between tinnitus loudness level (TLL) and internal jugular venous flow rate (IJVFR) in tinnitus patients with a unilateral high jugular bulb detected by temporal bone high-resolution computed tomography (HRCT). The study group consisted of 24 adult patients (13 male, 11 female) with a unilateral high jugular bulb. One ear suffered from tinnitus with a high jugular bulb was included into the study group. The ears without tinnitus and no high jugular bulb on temporal bone HRCT comprised the control group. All patients were evaluated with a history and physical and otolaryngologic examinations, and, using a questionnaire, TLLs were detected. The patency and flow rates in the internal jugular veins were measured by right and left internal jugular venous Doppler ultrasonography. The TLLs were "very quiet" in 1 (4.1%) patient, "intermediate loud" in 17 (70.9%) patients, and "very loud" in 6 (25.0%) patients. IJVFRs were not different in the study and control groups. In the study group, IJVFRs were not correlated with age. There was no relationship among TLLs and IJVFRs, dominance, dehiscence, and bony septum thickness between the high jugular bulb and the middle ear. TLLs were not affected by IJVFRs, dominance, dehiscence, and bony septum thickness in patients with a high jugular bulb. More detailed studies should be undertaken to determine the reason for the different TLLs in patients with a high jugular bulb.     

Genetic differentiation of methicillin-resistant Staphylococcus aureus strains from Korea and Japan

In this study, we evaluated genetic differentiation between methicillin-resistant Staphylococcus aureus (MRSA) strains from Korea and Japan. Seventy-five MRSA strains, including 25 h VISA strains, were analyzed by molecular typing methods, including multilocus sequence typing (MLST), SCC mec typing, and spa typing. The most prevalent genotype of MRSA strains, in both Korea and Japan, was ST 5-MRSA-II with the DMGMK spa motif, characteristic of the New York/Japan MRSA clone. In spite of these common features in MRSA strains from Korea and Japan, we also observed some genotypic divergence in MRSA from the two countries. Several spa types might be differentiated from a prevalent prototype (TJMBMDMGMK) that is shared by the two countries, revealing a unique geographic distribution. SCC mec type II lacking pUB110, designated type IIA, was found more frequently in Korea than in Japan. The rate of gentamicin resistance was also dramatically different between the two countries: 87.2% (Korea) vs. 28.6% (Japan). These preliminary findings suggested that MRSA strains from Korea and Japan might have originated from a common ancestor, but then clearly differentiated according to locality. A further comprehensive study should be performed to document the hypotheses from this study.     

A thin carboxymethyl cellulose culture substrate for the cellulase-induced harvesting of an endothelial cell sheet

Engineered tissues constructed with two-dimensionally organized cells provide promising parts for reconstructing damaged tissues. Here we propose a new method for fabricating a 2D sheet made of an endothelial cell monolayer. First a culture substrate was prepared by treating the glass surface with an amine-terminated organosilicon derivative, followed by the covalent attachment of a thin carboxymethyl cellulose (CMC) layer. Fibronectin was immobilized onto the CMC-coated surface to promote cell adhesion. These surfaces were characterized step by step by means of contact angle measurement and X-ray photoelectron spectroscopy. Porcine aortic endothelial cells adhered to the culture substrate and consequently formed a confluent monolayer. When the substrate-cell composite was immersed in a cellulase solution, a cell sheet was spontaneously detached from the substrate due to enzymatic digestion of the CMC layer. The cell-cell connections were well preserved in the cell sheet, even after detachment from the substrate, most likely due to the fact that cellulase is harmless to mammalian cells. The cell sheet could be transferred to other culture dish with the aid of a hydrophilic membrane support, retaining the proliferation activity of the cells. The results obtained in this study demonstrate that cellulase treatment of the CMC layer is a rational and efficient method for obtaining a 2D cell sheet.     

Familial-associated mutations differentially disrupt the solubility, localization, binding and ubiquitination properties of parkin

Mutations in parkin are largely associated with autosomal recessive juvenile parkinsonism. The underlying mechanism of pathogenesis in parkin-associated Parkinson's disease (PD) is thought to be due to the loss of parkin's E3 ubiquitin ligase activity. A subset of missense and nonsense point mutations in parkin that span the entire gene and represent the numerous inheritance patterns that are associated with parkin-linked PD were investigated for their E3 ligase activity, localization and their ability to bind, ubiquitinate and effect the degradation of two substrates, synphilin-1 and aminoacyl-tRNA synthetase complex cofactor, p38. Parkin mutants vary in their intracellular localization, binding to substrates and enzymatic activity, yet they are ultimately deficient in their ability to degrade substrate. These results suggest that not all parkin mutations result in loss of parkin's E3 ligase activity, but they all appear to manifest as loss-of-function mutants due to defects in solubility, aggregation, enzymatic activity or targeting proteins to the proteasome for degradation.     

Substance initiation sequences among Taiwanese adolescents using methamphetamine

The aim of this study was to examine substance initiation sequences in Taiwanese adolescent methamphetamine (MAMP) users. Three hundred adolescent MAMP users were questioned about their use of cigarettes, alcohol, areca quid, benzodiazepine, glue, marijuana, MAMP and heroin. The sequences of substance use before MAMP use were determined in every subject according to their age at substance initiation. The sequences of substance initiation were compared between genders and between early-onset and late-onset MAMP users. The results revealed that the adolescents had used cigarettes, alcohol and areca quid before MAMP, and very few (4%) adolescents had started using MAMP before using other substances. Female MAMP users were more likely to use MAMP as their first substance and were less likely to use areca quid than males. Male early-onset MAMP users were more likely to drink alcohol and chew areca quid before MAMP use than were late-onset users. This study found that the sequences of substance initiation were different between genders and between the early-onset and late-onset MAMP users. There are several findings that are different from those in Western studies on the sequence of substance initiation in the adolescent population.     

Fanconi-Bickel syndrome in three Turkish patients with different homozygous mutations

Three Turkish patients with Fanconi-Bickel syndrome are presented. Prominent clinical findings of patients included hepatomegaly, growth retardation, hypoglycemia, characteristic tubular nephropathy, and rickets. Each patient had a different homozygous mutation of glucose transporter 2 (GLUT2) gene.     

Inflammatory bowel disease-like colitis in a young Turkish child with glycogen storage disease type 1b and elevated platelet count

Inflammatory bowel disease (IBD)-like colitis is a known entity in glycogen storage disease (GSD) type 1b patients. The mean age of the reported cases with IBD-like colitis was 12 +/- 5 years, and all had absolute neutrophil count (ANC) less than 1,000 cells/microl. We report a three-year-old girl with GSD type 1b that was dignosed by mutation analysis. The patient was hospitalized with fever, diarrhea, and perioral and anal ulcers. Colonoscopy was performed and IBD-like colitis was diagnosed. The patient had elevated platelet count beyond the age of three months, but IBD-like colitis was diagnosed at three years of age. An elevated platelet count may be a warning sign for the IBD-like colitis in young patients with GSD type 1b.     

Pax3 mRNA is decreased in the hearts of rats with experimental diaphragmatic hernia

Rats with nitrofen-induced congenital diaphragmatic hernia (CDH) have heart hypoplasia and cardiovascular malformations. The mechanism of action of nitrofen involves changes in neural crest signaling. Pax3 function is required for cardiac neural crest cells to complete their migration to the developing heart. The aim of this study was to examine whether Pax3 expression is changed at two gestational endpoints in rat embryos or fetuses exposed to nitrofen. On day E9.5 of gestation, pregnant rats received either 100 mg of nitrofen (n=10) or vehicle alone (control, n=10). The fetuses were recovered on E15 or E21. Their hearts were dissected out and weighed. Pax3 mRNA expression was determined by real-time polymerase chain reaction. We used two-tailed Students t-tests to compare groups, with a threshold of significance of p<0.05. Compared with controls, nitrofen-exposed fetuses had heart hypoplasia in terms of heart/body weight ratio (0.62±0.10% vs. 0.77±0.17%, p<0.05). Pax3 mRNA expression in the heart was significantly decreased on E15 in nitrofen-treated embryos (32.94±17.11 U vs. 55.09±11.56 U, p<0.05), and it was still decreased, although not significantly, in the hearts of nitrofen-exposed fetuses recovered on E21 (15.67±5.56 U vs. 20.51±5.92 U, not significant). In conclusion, Pax3 is underexpressed in the hearts of nitrofen-exposed embryonal rats before the end of gestation. The mechanism of action of Pax3 should be further investigated because it could be one of the targets for future prenatal transplacental intervention.Paper presented at the XVIIth International Symposium of Pediatric Surgical Research, Liverpool, United Kingdom, 1–2 October, 2004.