Machining accuracy of CAD/CAM ceramic crowns fabricated with repeated machining using the same diamond bur

The purpose of this study was to investigate the effect of repeated machining up to 51 times using the same diamond bur on machining accuracy of inner and outer surfaces of CAD/CAM (computer-aided designing and computer-aided manufacturing) machined ceramic crowns. The surface topography of machined crowns was examined using photographs. It was found that machining accuracy was not affected by the number of machining times. In all measuring points, the inner surface was machined to a dimension larger than the die model (i.e., increased gap), whereas the outer surface was machined to a dimension smaller than the crown model (i.e., smaller crown). Photo observation showed that cervical contour was machined in a clear, rounded form from 1st to 11th crowns.     

Characterization of novel staphylococcal enterotoxin-like toxin type P

We investigated the biological properties of a novel staphylococcal enterotoxin (SE)-like toxin type P (SElP). SElP induced a substantial proliferative response and the production of cytokines interleukin-2, gamma interferon, tumor necrosis factor alpha, and interleukin-4 from human T cells when administered at a concentration of 0.4 pM (0.01 ng/ml) or more. The expression of major histocompatibility complex class II molecules on accessory cells was required for T-cell stimulation by SElP. SElP selectively stimulated a vast number of human T cells bearing receptors Vbeta 5.1, 6, 8, 16, 18, and 21.3. These results indicated that SElP acts as a superantigen. SElP proved to be emetic in the house musk shrew emetic assay, although at a relatively high dose (50 to 150 mug/animal). A quantitative assay of SElP production with 30 Staphylococcus aureus strains harboring selp showed that 60% of these strains produced significant amounts of SElP in vitro. All 10 strains carrying seb and selp produced SEB but not SElP, suggesting the inactivation of the selp locus in S. aureus strains with a particular se gene constitution.     

Augmentation of Helicobacter pylori urease activity by its specific IgG antibody: implications for bacterial colonization enhancement

Gastric colonization of Helicobacter pylori (H. pylori) occurs in a very early age via infected mothers having H. pylori-specific IgG antibodies that would be transplacentally transferred to infants. In addition, H. pylori urease-specific IgG was associated with chronic gastric atrophy and post-immunization gastritis is usually correlated with a strong local IgG response. These findings indicate that H. pylori-specific IgG antibodies, in particular its urease-specific IgG, may induce unfavorable influence on host resistance against H. pylori. Here, we show that we have found a unique H. pylori urease-specific IgG monoclonal antibody (MAb), termed S3, recognizing the conformational structure of the small subunit Ure-A, which enhanced the urease enzymatic activity. Such enhancement of the H. pylori urease activity induced by 1 microg of S3 was almost completely cancelled by simultaneously added the same amount of L2 MAb, which has a strong and specific inhibitory activity against H. pylori urease and recognizes a liner epitope of 8-mer peptide (F8: SIKEDVQF) within its large subunit Ure-B (Infect. Immun. 69: 6597, 2001). Intravenous pre-administration of purified S3 into BALB/c mice showed significant augmentation for gastric colonization with the susceptible strain Sydney Strain-1 (SS-1). To our knowledge, this is the first demonstration that a H. pylori urease-specific IgG MAb induced an augmentation of their gastric colonization in vivo.     

Clinical results in severe carpal tunnel syndrome and motor nerve conduction studies

The purposes of this study were to assess the value of motor nerve conduction studies as a prognostic indicator for severe carpal tunnel syndrome (CTS) and to investigate residual nerve disorder after surgery. Fifty hands in 46 patients with severe CTS were followed for at least 6 months after surgery for open carpal tunnel release. Compound muscle action potential (CMAP) from the abductor pollicis brevis (APB) muscle and the second lumbrical (SL) muscle were recorded before and after surgery, and distal latency (DL) and amplitude were analyzed. APB-CMAP was not recordable in 43 hands while SL-CMAP was recordable in all 50 hands before surgery. Results were excellent in 28 hands, good in 16 hands, fair in 6 hands, with no poor results after surgery. The ratio of excellent result was 65% in patients in whom DL of preoperative SL-CMAP was less than 10ms, and 20% in patients whose DL was 10ms or more. Delayed DL was seen in postoperative APB-CMAP and SL-CMAP, especially in the patients with good or fair results. We consider that SL-CMAP was valuable as a prognostic indicator for severe CTS, and if DL was 10ms or more, myelinization of fibers would not be sufficient after surgery.     

Methemoglobinemia induced by automobile exhaust fumes

Although methemoglobinemia is an uncommon disorder, it should always be considered in the differential diagnosis of cyanosis. Major causes of acquired methemoglobinemia are nitrates, aniline, and analgesics, though rare cases have been reported to have been caused by automobile exhaust fumes. A 24-year-old man had inhaled a large amount of automobile exhaust fumes, intending to commit suicide. He had become unconscious, with dilated pupils and symptoms of cyanosis. Arterial hemoglobin oxygen saturation (Sp_O2) was 86%, with a methemoglobin level of 44.3% and a carboxyhemoglobin level of 0%, while electrolytes, blood urea nitrogen, creatine, and glucose measurement results were normal. He was treated with methylene blue 250 mg (approximately 4 mg/kg) through a nasogastric tube. Four hours after the treatment, because the methemoglobin level was slightly above normal (2.2%), we added 180 mg of methylene blue. The results of final arterial blood gas analysis were a methemoglobin level of 0.4% and a carboxyhemoglobin level of 0.8%. He recovered uneventfully and returned home by himself the next day. To summarize, we successfully treated, with methylene blue given through a nasogastric tube, a young man who had developed severe methemoglobinemia from inhaling automobile exhaust fumes.     

Relationship between lifestyle scores and salivary stress markers cortisol and chromogranin A

The authors evaluated individuals' lifestyles and investigated the relationship between lifestyle scores and the incidence of salivary stress markers cortisol and chromogranin A (CgA). Saliva samples from 173 healthy male workers were tested by enzyme-linked immunosorbent assay for salivary cortisol and CgA levels. Questionnaires concerning lifestyle were administered: respondents aged 20-39 years who had good scores for comprehensive lifestyle showed significantly lower levels of cortisol than did respondents with moderate or poor comprehensive lifestyle scores. Respondents aged 40-59 who scored better for general lifestyle than they did during the previous year showed significantly lower levels of CgA than did respondents reporting no improvement. These findings suggest that levels of salivary cortisol may be affected by current circumstances and that levels of CgA may be affected by changes in comprehensive lifestyle.     

A case of accelerated acute rejection in kidney transplantation rescued by plasma exchange

A 30-year-old female received living donor kidney transplantation from her mother. The surgical procedure was uneventfully performed and urine output was observed a few minutes after reperfusion. However, 24 hours after the surgery, the urine volume rapidly decreased with worsened renal blood flow as determined by Doppler ultrasonography, diagnosed as accelerated acute rejection (AAR). Plasma exchange (PE) combined with therapies including administration of steroids and OKT3 dramatically improved the renal status, resulting in maintenance of good renal function (serum Cr; 1.5 mg/dl) even after 18 months PE was considered as a powerful tool for AAR, and the literature was reviewed.     

Ionic strength influences hemolytic action of dibucaine hydrochloride

BACKGROUND: Little is known about effect of ionic strength on local anesthetic toxicity. Using human erythrocytes, hemolytic action of dibucaine in solutions of various ionic strength was investigated. METHODS: The critical micellar concentration (CMC) of dibucaine and the dibucaine level that causes destruction of half of the red blood cells in vitro (EC50 value) were determined in solutions of various ionic strength. RESULTS: The mean CMC values of the dibucaine solutions adjusted to ionic strength 0.15, 0.30, 0.45 and 0.90 with NaCl, were 35.3, 22.6, 15.9 and 9.6 mM, respectively. The mean EC50 values of these solutions measured at 5 sec were 22.5, 16.0, 12.6 and 8.2 mM, respectively, and those at 30 min were 4.9, 4.5, 4.5 and 2.6 mM, respectively. There was a significant correlation between mean CMC values and mean EC50 values at 5 sec but not at 30 min in the solution of the same ionic strength. CONCLUSIONS: These findings indicated that the mechanism of dibucaine-induced hemolysis within a few seconds is through membrane lysis, whereas dibucaine-induced hemolysis at 30 min is caused by another mechanism. Because each mechanism is enhanced by high ionic strength, dibucaine dissolved in salt solution should not be administered intrathecally.