Biomedical subjects
Publications and source records attributed to J C Hwang.
The purpose of this investigation is to identify the synthetic nonabsorbable monofilament suture that requires the lowest forces for removal of continuous dermal sutures. Immediately after wound closure, continuous dermal polypropylene sutures require the lowest suture removal forces. The ease of polypropylene suture removal from continuous dermal skin closure is related to the suture's low surface coefficient of friction.
Amounts of whole-body metallothionein (MT) in tilapia (Oreochromis mossambicus) larvae increased to a peak (1,500 ng mg(-1) protein) 1 d after hatching (H1), decreased rapidly thereafter, and was maintained at a constant level (700 ng mg(-1)) 3 d after hatching (H3). Waterborne Cd(2+) could stimulate MT expression in newly hatched (H0) larvae in dose-dependent and time-dependent patterns. H0 larvae, which were treated with 35 microg L(-1) Cd(2+) for 24 h, showed a 1.7-fold increase in the MT amount (174.0+/-64.7) and a 6. 5-fold increase in accumulated Cd(2+) but no significant change in Ca(2+) content, compared with the H0 control (MT, 102.6+/-48.1). H3 larvae with the same treatment revealed about a 10-fold increase in accumulated Cd(2+), a 10% decrease in Ca(2+) content, but no change in MT (261.2+/-120.0), compared with the H3 control (MT, 330+/-74.0). H0 larvae could synthesize more MT to bind Cd(2+) for detoxification in 35 microg L(-1) Cd(2+), a dose that would not affect normal physiology or survival of H0 larvae. On the other hand, 35 microg L(-1) Cd(2+) caused H3 larvae to experience hypocalcemia, an abnormal physiological condition, in which H3 larvae could not synthesize sufficient MT, thus causing greater than 25% mortality. These results indicate for the first time that the inducibility of MT by waterborne Cd(2+) is development dependent, being correlated with inconsistent sensitivities to Cd(2+) during larval development.
An automated hydrotherapy water treatment system was described that controls chemical pumps that maintain the pool's water pH and chlorine levels at the designated set points, regardless of the bather load. This system consists of sensing electrodes, a controller, and positive displacement pumps. Because outbreaks of waterborne infections have never been reported in facilities in which the pool water has been continuously maintained at pH 7.2 to 7.8 with a free available chlorine level of at least 1.0 ppm, we recommend that this type of water treatment system be installed in all public pools.
The Board of Health of the Commonwealth of Virginia has an outdated sanitary code for its public hydrotherapy and swimming pools. The code is restricted to pools in hotels and other lodging places. The absence of modern regulations for public hydrotherapy and swimming pools has permitted serious deficiencies in pool maintenance, which are highlighted in this report. The most notable of these deficiencies was the presence of high levels of bacterial contamination that could predispose to infect in the water of one public hot tub. The results of this study indicate that the Virginia Board of Health sanitary code for pool water must be revised immediately and should include all public hydrotherapy and swimming pools. Other states and communities may want to assess their codes for swimming pools and hydrotherapy tubs to avoid deficiencies that could be detrimental to public health.
A search in ancient Chinese medicinal literature and modern phytochemical references indicates that the therapeutic value of Leonurus artemisia (I-mu ts'ao, the Chinese motherwort) might reside in a uterotonic principle present in leaves. Leonurine (4-guanidino-n-butyl syringate) was isolated from fresh and dry leaves of Leonurus artemisia. The uterotonic effect of leonurine was demonstrated in rat uterus in vitro. Results from this study suggest that functional phytochemistry based on ethnobotanical experience could lead to development of new and effective drugs from Chinese medicine.
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OBJECTIVE: To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. MATERIALS AND METHODS: Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n = 16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. RESULTS: Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p <0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62). CONCLUSION: For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.
We report MR findings in a case of a solitary fibrous tumor involving the buccal space in a middle-aged man. On MR images, most of the mass was isointense and hyperintense to the muscle on T1- and T2-weighted images, respectively, and showed homogeneously strong enhancement on contrast-enhanced T1-weighted images. The medial peripheral portion, which was isointense on T2-weighted images and showed less enhancement on contrast-enhanced T1-weighted images, corresponded to the hypocellular and collagenous sclerotic area on pathologic correlation.
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