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Biomedical subjects

C C Yang

Publications and source records attributed to C C Yang.

At least 55 records · Page 3Linked to original sources
PubMed2001

The correlation between alteration of p16 gene and clinical status in oral squamous cell carcinoma.

The purpose of the study was to evaluate the presence of alteration of the tumor suppressor gene p16 and to correlate these changes with the clinical status of the patients in oral squamous cell carcinoma. Forty-eight oral squamous cell carcinomas were included in the analyses. Deletion analysis was performed by the polymerase chain reaction (PCR). Mutation analysis was restricted to exon 1 and exon 2 of the p16 gene, previously shown to have a high incidence of mutations. The sequences containing exon 1 and exon 2 were amplified by PCR and screened with a single-strand conformation polymorphism (SSCP) technique. Samples showing band shifts in SSCP were sequenced by PCR direct sequencing. Western blots were used to detect the protein expression of the p16 gene, and the results were evaluated with regard to their biological relevance in correlation with clinicopathological factors. Seven (14.6%) deletions were found; 5 (10.4%) mutations were discovered and located in different codons; 26 (54%) specimens had no p16 protein expression; in 11 specimens with p16 deletion or mutation, p16 protein could not be detected. One mutation was non-sense. The p16 gene alterations showed no relationship with location and clinical stage of cancer; however, a close relationship between p16 alterations and cancer metastasis to neck lymph node was found. The alteration rate gradually elevated from well to poorly differentiated grades. We perceive two results. First, the alterations of the p16 gene are common in oral squamous cell carcinoma. Second, the alterations of the p16 gene may attribute to the metastatic behavior or histological grade of cancer cells.

Adult↗
PubMed2001

Perinephric abscesses in the neurologically impaired.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: To document the occurrence and management of large perinephric abscesses in neurologically impaired patients at high risk for this infectious complication. SETTING: US Veterans Affairs hospital. METHODS: The records, radiographs, operative findings and outcomes of all patients who presented with perinephric abscesses evident on physical exam within the last 5 years were reviewed. RESULTS: Four patients presented with large perinephric abscesses evident on physical examination. All had severe neurologic impairment with high sensory levels; three had spinal cord injuries, one had advanced multiple sclerosis. All had neurogenic bladders and recurrent urinary tract infections. The diagnosis was made through a combination of history, physical examination and computed tomography (CT) examination. All were found to have upper tract obstruction. All were managed with immediate abscess drainage and three had elective nephrectomy once the infection had resolved. No patients died of their perinephric abscess. CONCLUSIONS: These four cases illustrate that although advances in antibiotics, imaging and percutaneous management have improved the speed of diagnosis and reduced the mortality in patients with perinephric abscesses, the neurologically impaired population continues to remain at significant risk for the development and the delayed diagnosis of these morbid renal infections.

Abdominal Abscess↗
PubMed2001

Acute toxicities of betel nut: rare but probably overlooked events.

BACKGROUND: Betel nut chewing has long been a social habit in Taiwan and other Asian and tropical countries. It produces various autonomic and psychoneurologic effects including tachycardia, flushing, warmth, cholinergic activation, alertness, and euphoria. Although the oral carcinogenic effects are well known, data concerning its acute toxicity are few. To better understand the toxicity of betel nut, cases reported to the Taiwan Poison Control Center as probable or possible betel nut-related toxicity (January 1988-June 1998) were reviewed. In the 17 cases suitable for review (14 males, 3 females, age 21 to 60 years), the most common manifestations were tachycardia/palpitations (7); tachypnea/dyspnea (6); hypotension and sweating (5); vomiting, dizziness, and chest discomfort (4); abdominal colic, nausea, numbness, and coma (3); and acute myocardial infarction and related manifestations (2). The reported quantity of betel nut used was low (1 to 6 nuts), except an extract of 100 betel nuts was used in 1 case and 66 chewed in another. Most cases recovered within 24 hours after the exposure. One patient developed probable acute myocardial infarction and ventricular fibrillation and died despite repeated cardiac defibrillation. Although betel nut chewing is widespread, significant toxicity as reported to a poison center is rare. Because most betel nut-related effects are transient and mild in nature, the incidence of such events is likely to be underreported. Nevertheless, betel nut chewing can produce significant cholinergic, neurological, cardiovascular, and gastrointestinal manifestations. It is possible that it may aggravate cardiac diseases in susceptible patients but this hypothesis must be further investigated. Treatment is symptomatic. With timely support, rapid and complete recovery is anticipated but a small risk of major complications cannot yet be discounted.

Adult↗
PubMed2001

Acute ethylene chlorohydrin poisoning: experience of a poison control center.

BACKGROUND: Ethylene chlorohydrin (CAS 107-07-3), a chemical once used in hastening grape vine sprouting in Taiwan, has caused severe toxicity upon acute exposure. Although such use of ethylene chlorohydrin is now prohibited in Taiwan, poisoning still occurs following its illegal use. Since data concerning human ethylene chlorohydrin poisoning remain rare, we report our experience in treating acute ethylene chlorohydrin-poisoned patients. METHODS: A retrospective analysis was conducted to evaluate patients with ethylene chlorohydrin poisoning reported to Taiwan Poison Control Center during 1985-1998. RESULTS: Seventeen patients with ethylene chlorohydrin poisoning were identified. There were 11 male and 6 female patients, ranging in age from 2 to 70 years (median 53 years). The intent of exposure was suicide in 5, accident in 9, and occupational exposure in 3 patients. Oral ingestion was the most common route of exposure (14 patients). Seven out of the 17 patients died within 24 hours due to metabolic acidosis and respiratory failure. Ethanol therapy, used in 2 patients, had no apparent benefit. Moderate or mild poisoning was characterized by gastrointestinal effects only and an uneventful recovery. CONCLUSIONS: Ethylene chlorohydrin can result in severe metabolic acidosis, respiratory failure, coma, and death after acute exposure.

Accidents↗
PubMed2001

Anti-HBc IgG subclasses in different populations by comparing a variety of ELISA plates.

The number of IgG subclasses for hepatitis B virus (HBV) core antigen (anti-HBc), demonstrated for HBV-infected individuals, was measured by enzyme-linked immunosorbent assay (ELISA). Four commercially available hepatitis B core antigen (HBcAg) plates and one prepared plate were tested for ELISA sensitivity by the detection of 14 serum samples drawn from HBV chronic carriers, cured patients, vaccinees, and non-infected individuals. Differences in optical density (OD) values were obtained by comparing data gathered from the five plate types, suggesting that different plates may have different binding capabilities for each anti-HBc IgG subclass and, thus, contribute to the different ELISA sensitivities. Of these plates, the GB plate showed the most obvious absorbance changes for anti-HBc subclasses in different populations. These data also indicated different patterns for IgG-specific subclasses for various populations. For HBsAg+ carriers, the OD for IgG1 was greater than for IgG3. By contrast, the OD for IgG3 was higher than that for IgG1 in those subjects who were negative for HBsAg.

Adult↗
PubMed2001

Abdominal wall abscess secondary to spilled gallstones: late complication of laparoscopic cholecystectomy and preventive measures.

Spilled gallstones left in the abdominal cavity or trapped at trocar sites may cause considerable morbidity. We saw a patient with an abdominal wall abscess 2 years after laparoscopic cholecystectomy secondary to spilled stones. After we reviewed the operative procedure in addition to the accumulated experience in laparoscopic surgery, we believe that retrieval of specimens and their contents is of paramount importance, especially when the gallbladder is infected, contains several stones, or may harbor malignancy. Therefore, we made use of a simple surgical glove with a long pursestring suture surrounding the opening to collect the specimen. This method proved to be simple and quite convenient, with the needed materials readily available. It can collect the spilled stones within the abdominal cavity as well as the gallbladder and can transport these stones out of the abdominal cavity with ease and safety. It also protects the specimen in contact with the wound and cuts short the operating time. The technique and advantages are described.

Abdominal Abscess↗
PubMed2001

The role of a beta-bulge in the folding of the beta-hairpin structure in ubiquitin.

It is known that the peptide corresponding to the N-terminal beta-hairpin of ubiquitin, U(1-17), can populate the monomeric beta-hairpin conformation in aqueous solution. In this study, we show that the Gly-10 that forms the bulge of the beta-turn in this hairpin is very important to the stability of the hairpin. The deletion of this residue to desG10(1-16) unfolds the structure of the peptide in water. Even under denaturing conditions, this bulge appears to be important in maintaining the residual structure of ubiquitin, which involves tertiary interactions within the sequence 1 to 34 in the denatured state. We surmise that this residual structure functions as one of the nucleation centers in the folding process and is important in stabilizing the transition state. In accordance with this idea, deleting Gly-10 slows down the refolding and unfolding rate by about one half.

Amino Acid Substitution↗
PubMed2001

Evidence for alterations in circulating low-molecular-weight antioxidants and increased lipid peroxidation in smokers on hemodialysis.

BACKGROUND/AIM: Cardiovascular disease is the major cause of mortality in dialysis patients, accounting for about 40% of deaths in most large registries. Oxidative stress has been strongly implicated in the pathogenesis of these events. As end-stage renal disease is a state of elevated free radical activity, the aim of the present study was to investigate the negative impact of smoking in 57 male hemodialysis patients. METHODS: The patients, who were 20-85 years of age (mean age 51.0 +/- 14 years), had been on hemodialysis for at least 6 months before participating in this study. Fasting blood sampling for serum lipid, albumin, urate and lipophilic antioxidants such as tocopherols, carotenes, ascorbate and lipid peroxides was performed. RESULTS: The plasma malondialdehyde (MDA) concentration was significantly higher in hemodialysis patients who smoked compared to hemodialysis patients who were nonsmokers (1.92 +/- 0.52 vs. 1.59 +/- 0.42 nmol/ml, p = 0.006). No association was found between levels of MDA in smokers and parameters such as body mass index, serum cholesterol, serum triglycerides and smoking index. There were no significant differences in the plasma levels of uric acid, alpha-tocopherol, gamma-tocopherol, delta-tocopherol, alpha-carotene, beta-carotene and retinol between the two groups. A significantly lower level of plasma ascorbate was observed in hemodialysis patients who smoked compared to the nonsmoking hemodialysis patients or healthy controls (4.59 +/- 4.0 vs. 9.57 +/- 4.0 and 10.16 +/- 4.6 microg/ml, p < 0.05). Moreover, in smokers, the plasma levels of ascorbate were negatively correlated with the levels of plasma MDA (r = -0.43, p < 0.001) of each patient. Partial correlation analysis of the plasma levels of the measured antioxidants and the smoking index revealed a negative correlation between the plasma levels of lipid-normalized lycopene and the smoking index (r = -0.53, p < 0.05). CONCLUSION: Our data suggest that cigarette smoking further increases plasma-circulating products of lipid peroxidation, which are already increased in nonsmoking hemodialysis patients as compared to matched healthy controls. The lower plasma levels of ascorbate in hemodialysis patients who smoke suggest that these patients may be more susceptible to oxidative tissue damage caused by smoking.

Adult↗
PubMed2001

Tracheal length of infants under three months old.

The measurement of tracheal length in infants is difficult to perform in vivo. In adults, tracheal length may be consistent with age, but in infants, tracheal length may vary much more with age and other factors. This study used video rigid ventilation bronchoscopy to evaluate the length of the airway, concentrating on the population younger than 3 months old. There were 34 infants in this study: 14 boys and 20 girls. The mean length from the superior border of the vocal fold to the carina was 5.04 cm, and the mean tracheal length (from the ridge of the first tracheal ring to the carina) was 4.12 cm. There was no significant difference between boys and girls in the length from the vocal fold to the carina or in the tracheal length. The length from the vocal fold to the carina is best correlated to body weight, followed by body height and age.

Anthropometry↗
PubMed2001

Physiologic studies of male sexual dysfunction in multiple sclerosis.

OBJECTIVE: We conducted this investigation to better define the neural disruptions that result in sexual dysfunction in men with multiple sclerosis (MS), using genital electrodiagnostic testing and nocturnal penile tumescence and rigidity monitoring. METHODS: Thirteen men with MS and sexual dysfunction were recruited for the study. Twelve healthy, sexually potent men were enrolled as controls. All underwent pudendal somatosensory evoked potential (SEP) testing using standard methods, and a new modification to isolate the right and left dorsal nerves of the penis. RigiScan testing was performed on the MS subjects to assess nocturnal erectile function. RESULTS: Unilateral and bilateral DNP SEPs were able to be performed on the control subjects. In all but one MS subjects, DNP SEP abnormalities were found. Three men had normal latency bilateral DNP SEP latencies, but on unilateral DNP testing, abnormalities were identified. Seven men, including those with abnormal or absent SEP latencies, had normal nocturnal erectile activity. There was no correlation between overall functional status, presence of abnormal or absent SEP, and quality of nocturnal erectile activity. CONCLUSIONS: Genital SEP abnormalties are common in men with MS and sexual dysfunction. Unilateral DNP SEP testing was more sensitive in identifying abnormalities than the standard method of pudendal SEP testing. One of the causes of sexual dysfunction in men with MS may be due to genital somatosensory pathway disruption, with sparing of the efferent tracts in some men.

Adult↗
PubMed2001

Bethlem myopathy in a Taiwanese family.

We report three cases of Bethlem myopathy from three consecutive generations of a Taiwanese family, including one woman aged 70, one man aged 40, and a boy aged 8. The clinical features of the patients included autosomal dominant inheritance, childhood or adolescent onset, mainly proximal and extensor involvement, early diffuse joint contractures, and absence of cardiac involvement. These features fulfilled the diagnostic criteria for Bethlem myopathy. Though the clinical course of the disease was once thought to be benign, our female patient became wheelchair-bound at the age of 53. This suggests that the disease process in Bethlem myopathy is slow but ongoing.

Adult↗
PubMed2001

In vitro cellular response of retinoic acid treated human oral cancer cell lines.

BACKGROUND: The purpose of this study is to identify the cellular response ofretinoic acid-treated human oral cancer cell lines. METHODS: Seven human oral cancer cell lines KB, SCC4, SCC9, SCC15, SCC25, OEC-M1, OC1 and OC2 were used for cell culture experiments. Direct cell number counting method was utilized to evaluate cellular response of these human oral cancer cells at the presence or absence of all-trans RA at 1 mM. RESULTS: Through 7-day observation, the cell population of SCC9, SCC15 and SCC25 of RA-treated groups decreased when compared with the non RA-treated groups. These three cell lines were further verified using [3H] thymidine incorporation DNA synthesis assay. KB, SCC4, OC1, OC2 and OEC-M1 cell lines did not show growth inhibition at the presence of RA at 1 mM. CONCLUSIONS: The molecular event of how SCC9, SCC15 and SCC25 are inhibited by RA and how KB, OC1, OC2 and OECM1 are resistant to RA can be further explored on the basis of this study.

Carcinoma, Squamous Cell↗
PubMed2001

Pancytopenia, hyperglycemia, shock, coma, rhabdomyolysis, and pancreatitis associated with acetaminophen poisoning.

It is well recognized that acetaminophen overdose can cause severe hepatic injury. However, extra-hepatic manifestations may also develop following inappropriate use or ingestion of large amounts of acetaminophen. We present a 44-y-o female who manifested coma, metabolic acidosis, shock, hypothermia, hyperglycemia, rhabdomyolysis, hepatotoxicity, and renal insufficiency after suicidal ingestion of an unknown amount of acetaminophen. Although her consciousness and hemodynamic status gradually improved after treatment with N-acetylcysteine and other supportive measures, she was found to have pancytopenia, pancreatitis and hepatorenal failure during the hospitalization and eventually died 18 d post-admission. Review of relevant literature reports and the clinical findings in our patient suggests that direct toxic effects mediated by acetaminophen or its metabolites were most likely responsible for most of the observed clinical features.

Acetaminophen↗
PubMed2001

Arthroscopic evaluation and treatment of scaphoid nonunion.

Scaphoid fractures are one of the most common carpal fractures and heal without complication in a majority of cases. Nonunion of the scaphoid, unfortunately, can occur secondarily to several reasons; namely, delay in treatment, delay in diagnosis, the intra-articular nature of the fracture, the precarious vascular supply of the scaphoid, and significant biomechanical stresses across the fractured scaphoid.

Adult↗
PubMed2001

Ellagic [correction of ellagica] acid inhibits arylamine N-acetyltransferase activity and DNA adduct formation in human bladder tumor cell lines (T24 and TSGH 8301).

The fact that vitamin C (ascorbic acid) exhibits a protective effect in certain types of cancer is well documented. Our previous studies demonstrated that human bladder tumor cell line (T24) has N-acetyltransferase (NAT) activity in cytosols and intact cells. The present studies examined the inhibition of arylamine NAT activity and carcinogen (2-aminofluorene)-DNA adduct formation by ellagic acid (EA) in human bladder tumor cell lines (T24 and TSGH 8301). Two assay systems were performed, one with cellular cytosols (9,000 g supernatant), the other with intact bladder tumor cell suspensions. NAT activity and 2-aminofluorene-DNA adduct formation in T24 and TSGH 8301 cells was inhibited by EA in a dose-dependent manner in both systems, i.e.. the greater the concentration of EA in the reaction the greater the inhibition of NAT activity (dose- and time-course dependent effects). The data also indicated that EA decreased the apparent Km and Vmax of NAT enzymes from T24 and TSGH 8301 cells in cytosols. NAT activity and 2-aminofluorene-DNA adducts in T24 is higher than in TSGH 8301. This report is the first to demonstrate that EA affects human bladder tumor cell NAT activity.

2-Acetylaminofluorene↗
PubMed2001

Bladder management in women with neurologic disabilities.

Women with neurologic disabilities can experience an array of bladder disorders. There are many aspects of lower urinary tract management that are specific to women. Treatments should be based on urodynamic findings, and individualized for each woman's physical and cognitive abilities.

Behavioral Medicine↗