Biomedical subjects
Publications and source records attributed to M J Yang.
Reversible Chinese words are words which can be read either from left to right or vice versa. The reversibility of reversible two-character Chinese words for 101 women and 73 men, native speakers of Chinese, was estimated.
BACKGROUND: There are few reports on maternal cerebral circulation during pregnancy. Using the hypothesis that cerebral blood flow resistance decreases progressively with advancing gestational age (GA) as a consequence of estrogenic effects on the vascular system during pregnancy, we calculated the pulsatility index (PI) and the mean velocity (MV) of the maternal right internal carotid artery (ICA) in order to build fitted reference centiles. METHODS: A total of 315 pregnant women with a single fetus were studied at 20-42 weeks' gestation. The patients had uncomplicated singleton pregnancies and were without any known fetal or maternal risk factors. Duplex color ultrasound with a pulsed Doppler scanner (7.5 MHz) was used to determine the PI and MV of the maternal ICA. RESULTS: Among the 315 healthy pregnant women, the PI of maternal ICA decreased progressively with advancing GA, PI50th = Exp (0.3124-0.0084 x GA), (p = 0.0003), during the second half of pregnancy. The predicted 50th percentile PI values of the ICA decreased from 1.117 (5th% = 0.755, 95th% = 1.654) at 24 weeks' gestation to 0.917 (5th% = 0.659, 95th% = 1.448) at 40 weeks' gestation. The MV of the maternal ICA also decreased progressively with advancing GA, MV50th = Exp (3.855-0.0093 x GA), (p = 0.0005), during the second half of pregnancy. The predicted 50th percentile MV values in the ICA decreased from 37.811 cm/sec (5th% = 24.177 cm/sec, 95th% = 59.138 cm/sec) at 24 weeks' gestation to 32.591 cm/sec (5th% = 20.818 cm/sec, 95th% = 51.021 cm/sec) at 40 weeks' gestation. CONCLUSIONS: Both the PI and MV of the maternal ICA decreased with GA during the second half of normal pregnancy as a result of intracerebral vessel dilatation.
PURPOSE: The intracolonic bypass tube has been used both experimentally and clinically to protect the anastomotic site. A newly designed intracolonic bypass, the Valtrac-secured intracolonic bypass, which consisted of a biofragmentable anastomosis ring (BAR) and was connected with a soft, thin vinyl tube, was used in the colon approximately 5 to 10 cm proximal to the anastomotic site. The distal end of the vinyl tube is passed through the colonic anastomosis to the anus to bypass the fecal stream. METHODS: Eighteen piglets were divided into three groups of six each. Group A piglets underwent colon resection and rough anastomosis with large gaps between sutures, followed by Valtrac-secured intracolonic bypass. Group B piglets underwent the same procedures, but a colonic outlet obstruction also was done with pursestring sutures tied over the anus. Group C piglets underwent colon resection and rough anastomosis, but no intracolonic bypass tube was inserted (as in the control group). RESULTS: All Group A and Group B piglets survived. Passage of the BARs occurred approximately two weeks later. As the barium enema passed through the bypass tube, it showed a patent BAR-secured tube and intact anastomosis with no leakage. In Group C, anastomotic leakage occurred in four of six piglets, three of which died. Barium enema showed leakage at the anastomotic site. CONCLUSIONS: In the animal model we used, our new intracolonic bypass device proved to be a simple, safe, reliable means of protecting the anastomotic site and, thereby, eliminated the need for a diverting colostomy. Still we need further steps to test its potential in clinical use.
OBJECTIVE: The nomogram of blood velocity flow resistance of the spiral arteries was built at 13-25 gestational weeks. Thereafter, by using the nomogram we tried to assess the results of the color Doppler examination of the uteroplacental circulation at the second trimester to predict pregnancy-induced hypertension (PIH) and small-for-gestational-age (SGA). METHODS: Two groups of patients were studied. Group 1, for the establishment of the nomogram, included 175 uncomplicated pregnancies with gestational ages ranging from 13-25 weeks. The Doppler flow waveforms of the spiral arteries were measured once for each pregnancy in the studies. Group 2 consisted of 305 singletons selected consecutively for prospective study to confirm the occurrence of PIH or SGA. They were scanned twice for the measurements of the spiral artery waveforms at 13-19 and 20-25 weeks, respectively to test which gestational weeks interval in the nomogram is most sensitive in predicting PIH and SGA. RESULTS: The 5th, 50th and 95th percentiles of the pulsatility index (PI) values of the nomogram at the second trimester were used as the cut-off points to predict pregnancies complicated with SGA or PIH at delivery. Using the receiver operator curve, the 50th percentiles of the PI values of the nomograms were chosen as predictives for the development of PIH and SGA. At 13-19 gestational weeks, the specificities in predicting PIH and SGA were 50.71% and 49.82%, respectively, and the sensitivities were 52.00% and 50.00%, respectively. The calculated Cohen's Kappa statistics were 0.008 and 0.001, respectively in predicting PIH and SGA. At 20-25 gestational weeks, the specificities in predicting PIH and SGA were 49.64% and 49.46%, respectively, and the sensitivities were 56.00% and 57.14%, respectively. The calculated Cohen's Kappa statistics were 0.017 and 0.022, respectively in predicting PIH and SGA. CONCLUSION: The measurements of uteroplacental blood flow velocity waveforms at the second trimester are not sensitive enough to be an early screening tool for PIH and SGA in the low risk, non-selected pregnancy population. The fact suggests that in most gravidas complicated with PIH and SGA, the physiological process of trophoblastic invasion in the spiral artery was not prevented before the 25th gestational week.
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The mechanism of mirror writing was investigated using legal Chinese characters and illegal pseudocharacters. It was found from the results of right-handers in experiment 1 that the performance of normal writing and mirror writing for legal characters was better than that of normal writing and mirror writing for pseudocharacters. A reasonable explanation for this character-superiority effect is that normal engrams and mirror engrams exist only for legal characters but not for pseudocharacters. Further analysis revealed that the character-superiority effect took place in normal writing only when the right hand was used and the same effect was observed in mirror writing only when the left hand was used. It seemed that the normal engrams used in normal writing were stored in the left hemisphere while the mirror engrams used in mirror writing were stored in the right hemisphere. The results in experiment 2 from the left-handers showed the similar pattern as that of the right-handers. The mirror-engram hypothesis seems to be the best mechanism to account for the performance difference of right hand and left hand in mirror writing.
We investigated the effect of three different recumbent positions on autonomic nervous activity in late pregnancy. Thirty pregnant and 24 nonpregnant aged-matched women were studied, and measures of heart rate variability in both time and frequency domains were compared using supine, right and left lateral decubitus positions. In the nonpregnant women, the normalised high-frequency power was greatest in the right lateral decubitus position. In the pregnant women, the normalised high-frequency power was lowest and the low/high-frequency power ratio was greatest in the supine position. Both the percentage decrease of normalised high-frequency power and the percentage increase of low/high-frequency power ratio in the supine and right lateral positions were greater than those in the left lateral position. For women in late pregnancy, the left lateral decubitus position may be beneficial because cardiac vagal activity is least suppressed and cardiac sympathetic activity is least enhanced. Aortocaval compression might be the mechanism underlying the change in cardiac autonomic nervous activity when supine and right lateral decubitus positions are assumed in late pregnancy.
BACKGROUND: Acetaminophen poisoning is a major cause of hospital admission and has been extensively reviewed. Its occurrence in pregnant women has been reported seldom, and the prognosis has been good except for one case, in which the fetus died. We report on a case of acetaminophen poisoning that resulted in the death of both the mother and the infant. CASE: A 38-year-old woman whose pregnancy was at 31 weeks' gestational age was evaluated for treatment of an acetaminophen overdose. She was admitted more than 26 hours after taking 35 g of acetaminophen. An emergency cesarean section was performed one hour after admission because of acute fetal distress. A grossly normal, 1,620-g, female infant was delivered and had Apgar scores at 1, 5 and 10 minutes of 0, 0 and 1, respectively, despite the initiation of resuscitation immediately following delivery. Acidosis was noted in the mother during the operation; it was followed by acute hepatorenal failure 16 hours after admission. That resulted in the mother's death 40 hours after admission. The infant also died 34 hours after delivery. CONCLUSION: Delays in administering the antidote treatment, N-acetylcysteine, after acetaminophen intoxication significantly increase the risk of mortality in both the mother and infant. The development of acidosis carries a poor prognosis in such patients and may necessitate liver transplantation to save the life of the mother.
BACKGROUND: Blood flow resistance of the subplacental spiral arteries in second-trimester pregnancies has not been previously reported. A reference range of blood flow resistance of the subplacental spiral arteries at 13-25 gestational weeks was designed in the hope the reference data could provide a basis for Doppler studies of pathologic disorders in second-trimester pregnancies. METHODS: A cross-sectional study was performed in 175 uncomplicated pregnancies at 13-25 gestational weeks. Doppler flow examinations of the subplacental spiral arteries were done. RESULTS: In the 175 normal pregnancies, both the predicted systolic/diastolic ratios(S/ D) (Y = 1.96258-0.02061x gestational age (GA), adjusted R2 = 0.03773, p = 0.003) and resistance indices (RI) (Y = 0.52131-0.00871 x GA, adjusted R2 = 0.03797, p = 0.003) of the subplacental spiral arteries decreased progressively with advancing gestational age. The predicted S/D value of the subplacental spiral artery decreased from 1.695 at the 13th week's gestation (5th% = 1.221, 95th% = 2.169) to 1.468 at the 24th week's gestation (5th% = 1.057, 95th% = 1.878). The predicted RI value of the subplacental spiral artery also decreased from 0.408 at the 13th week's gestation (5th% = 0.193, 95th% = 0.623) to 0.312 at the 24th week's gestation (5th% = 0.148, 95th% = 0.477). CONCLUSIONS: Normal blood flow resistance of the subplacental spiral arteries at 13-25 gestational weeks decreases progressively with advancing gestational age. The fact suggests that trophoblastic invasion of the spiral arteries occurred continuously throughout normal second-trimester pregnancies.
OBJECT: The aim of this study is to explore the influence of work experience on workers' psychological function. Specifically, the researchers will examine the effect of job demand, decision latitude, job strain, and social support at worksite on the mental health status of male heavy manufacturing workers. METHOD: By purposive sampling, from October 1994 to March 1995, the present investigators implemented a self-administered questionnaire survey on the workers in southern Taiwan. The Karasek job strain model and its measure were embedded in the questionnaire to evaluate workers' perceptions of their job conditions. In addition, Chinese Health Questionnaire (CHQ) was utilized to evaluate the workers' status of mental health. RESULT: Totally, 1,117 workers were selected for this survey. An unviriate analysis showed the younger the workers, the lower their monthly income, and the newer their employment, were more likely to be classified as high risk in mental health status. The workers with more decision latitude and higher social support would be better in mental health status. In addition, it also showed that workers under high job strain were more likely to be in poor mental health status. Result from multivariate logistic regression showed those who served longer, had more decision automony, and had higher social support, were less likely to be in poor mental health status. Instead, those who sustained high job strain were more likely to be in poor mental health status. DISCUSSION: The implication from those findings for the implementation of health promotion program. would be raised, and the limitation of this inference would also be discussed.
The purpose of this study was to explore how individuals' drinking behavior was associated with their jobs in terms of the amount consumed and its consequences. The researchers attempted to analyze the characteristics of job and workplace from structural, psychological, and cultural perspectives. The structural dimension referred to years serving in a company, years serving in a department, work position, work characteristics, and shift. The psychological dimension was addressed on perceived stress and work hazards. The cultural dimension of one's job consisted of formal and informal norms regarding one's drinking within the workplace. The result showed the occurrence of drinking-related problems was significantly associated with workplace subculture among the non-aboriginal Chinese males. However, none of the three perspectives as job characteristics was significantly associated with drinking amount. The findings imply that the workplace subculture plays a determinant role in affecting individual's drinking behavior, moreover, it could result in one's problem drinking.
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The aim of this survey study was to explore the influence of work on individual's drinking behavior. From October 1994 to March 1995, the present researchers implemented a self-administered questionnaire survey on workers in the manufacturing sector in Metropolitan Kaohsiung area, southern Taiwan. Of the 1,117 subjects selected, 668 (61.8%) stated that they had had one or more drinks during the preceding month. The average daily consumption of alcohol was 0.2 +/- 0.9 drinks (with a range of 0 to 12 drinks and a median of 0.02 drinks). In addition, 188 (28.8%) of the subjects reported having experienced drinking-related problems during the preceding month, and 35 respondents (5.2%) gave escape from job stress as the reason for their drinking in the preceding month. The result of multivariate analyses showed that workers who reported less autonomy in their job were more likely to experience drinking-related problems (odds ratio [OR] = 1.3) and to drinking for psychological relief (OR = 1.2); that workers who reported more demanding job conditions were more likely to drink for escape (OR = 2.5) but had lower levels of drinking (t = -2.5, p = 0.01); and that workers who reported high levels of job strain were more likely to experience drinking-related problems and to drink for relief but had lower levels of drinking. The details and implications of this result will be discussed.
PURPOSE: The biofragmentable anastomotic ring remains difficult to use for low rectal anastomosis. The authors report their experience of clinical application of the biofragmentable ring in low anterior resection with a newly designed instrument. METHODS: In this series, 31 patients underwent sphincter-preserving low anterior resections for rectal tumors from May 1993 to November 1994. With the assistance of a self-developed anastomotic instrument (biofragmentable anastomotic ring gun), biofragmentable ring anastomoses were performed following low anterior resection. RESULTS: There was no operative mortality. One patient had clinical evidence of anastomotic leakage. In postoperative follow-up, there was no anastomotic stenosis or incontinence. CONCLUSION: Therefore, we believe biofragmentable ring rectal anastomosis is a safe and reliable alternative to other anastomotic methods in rectal surgery.
BACKGROUND: Non-small cell lung cancer (NSCLC) has a relatively low response rate to systemic chemotherapy. Recently, several investigations have shown that interferon may augment the cytotoxic effect of chemotherapeutic agents and may improve the result of chemotherapy in treating cancers. METHODS: An open-label noncomparative phase II study investigated the efficacy and safety of combined chemoimmunotherapy for NSCLC using IFN-alpha, given by intramuscular injection with 9 million units thrice a week for a maximum of 26 weeks, and cisplatin by intravenous infusion, 100 mg/m2, every 4 weeks for a maximum of 6 cycles. Ten patients, with histology-confirmed NSCLC at stage IV of their diseases were enrolled. They included 5 men and 5 women, with an average age of 53.7 year. Five of them had adenocarcinoma; the other five had squamous cell carcinoma. RESULTS: Five patients, including two patients with squamous cell carcinoma and three with adenocarcinoma, obtained a partial response (response rate 50%). The time needed to achieve a sustained response ranged from 5 to 13 weeks with a median of 8 weeks. The response duration ranged from 14 to 37 weeks with a median of 20 weeks. The overall survival time for the ten patients ranged from 2 to 20 months with a median of 8 months. All 10 patients needed dose modifications of IFN-alpha and/or cisplatin because of myelosuppression and/or impaired renal function. Other frequently encountered side effects included gastrointestinal disturbances and a flu-like syndrome, but these were well tolerated. CONCLUSIONS: These preliminary results indicate that chemoimmunotherapy with IFN-alpha and cisplatin can be an effective alternative therapy for patients with advanced NSCLC, but there are significant side effects.
PURPOSE: The biofragmentable anastomotic ring (BAR) is now accepted as an alternative anastomotic method to handsewn and stapled anastomosis in colonic surgery. However, for a short rectal stump in a narrow pelvis, it is rather difficult to use the BAR in a low anterior resection. METHOD: To overcome the difficulty, we designed and used a BAR-adapter to facilitate biofragmentable ring anastomosis following low anterior resection in eight patients with rectal cancers. RESULTS: There was no case in our series having received conversion to other methods. There was no significant complication associated with this technique. CONCLUSION: With the BAR-adapter, the applicability of the BAR can be greatly expanded in colorectal anastomosis following low anterior resection.
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A rapid, simple, and nonradioactive method for diagnosing point mutations of c-K-ras oncogenes in gastroenterologic cancers is described. This method involved the selective amplification of DNA fragments from cancer tissues of surgical specimens with specific oligonucleotide primers, followed by digestion with restriction enzymes that recognized artificially created or naturally occurring restriction sites. To detect codon 12 mutations, an artificial Msp I site was created by introducing a single nucleotide mismatch into the 5' mutagenesis primer. Using a similar approach, an Hae III site was created to detect codon 13 mutations. Bal I and MBo II sites were used to detect codon 61 mutations. A total of 61 gastroenterologic cancer cases were studied. Of 35 cases of colorectal cancer, 7 showed mutations: 6 at codon 12 and 1 at codon 13. In 1 of 2 cases of cholangiocellular carcinoma, point mutation at codon 12 was found. One case of duodenal cancer showed point mutation at codon 12. No mutations were found in the cases of hepatocellular carcinoma (4), gastric cancer (12), esophageal cancer (3), or pancreatic cancer (2).