Biomedical subjects

Min-Chi Chen

Publications and source records attributed to Min-Chi Chen.

29 records · Page 2Linked to original sources

PubMed2003

Cervical degenerative disease at flexion-extension MR imaging: prediction criteria.

PURPOSE: To determine if there are any neutral-position imaging criteria that can help predict functional cord impingement at flexion-extension cervical magnetic resonance (MR) imaging. MATERIALS AND METHODS: Sixty-two patients with cervical degenerative disease were evaluated with regard to the dynamic changes of canal stenosis at flexion-extension MR imaging. Functional cord impingement was considered if the cord was impinged or more impinged after neck flexion or extension. Selection criteria for neutral-position MR imaging, such as cervical curvature, canal space, degenerative stage, intramedullary high signal intensity on T2-weighted images, and resting instability, were evaluated for their ability to predict functional cord impingement at flexion-extension MR imaging (Fisher exact test, logistic regression analysis). RESULTS: MR images in 19 (31%) of 62 patients showed functional cord impingement at extension MR imaging compared with images in two (3%) patients at flexion MR imaging. Statistically significant differences were found for the criteria cervical degeneration stage (P <.001) and spinal canal space (P =.037) for predicting functional cord impingement at extension MR imaging. In contrast, no significant differences were found among selection criteria for flexion MR imaging. Probabilities of functional cord impingement at extension MR imaging were calculated with different combinations of degenerative stages and canal spaces. Probability could increase to 79% if the patient had both stabilization degeneration (disk protrusion or osteophytic formation with hypertrophy of the ligamentum flavum) and C7 canal space of 10 mm or less. CONCLUSION: None of the selection criteria evaluated in this study has the ability to predict functional cord impingement at flexion MR imaging; however, prediction of impingement at extension MR imaging can increase from 31% to 79% if proper criteria are selected.

Adolescent↗

PubMed2003

A pilot study on a home-based caregiver training program for improving caregiver self-efficacy and decreasing the behavioral problems of elders with dementia in Taiwan.

OBJECTIVE: To investigate the effectiveness of a home-based caregiver training program for caregivers of elders with dementia and behavioral problems. METHODS: A prospective study was conducted in the communities of Northern Taiwan. Forty-eight patients with dementia and their family caregivers were included. The experimental group (n = 24) received a two-session in-home caregiver training program, and the control group (n = 24) received only written educational materials. The Chinese version of Cohen-Mansfield Agitation Inventory (CMAI), community form, was used to measure the behavioral problems of patients with dementia. The caregiver's self-efficacy, for managing the demented person's agitation, was measured by the Agitation Management Self-efficacy Scale (AMSS). The CMAI and AMSS were administered before (baseline), three weeks (1st post-test), and three months (2nd post-test) after the two-session training program. RESULTS: Except for the physically aggressive behavior subscale, the scores of physically non-aggressive behavior, verbally aggressive and non-aggressive behavior subscales as well as the overall CMAI decreased significantly and continuously in the experimental group and differed significantly from the changed scores from those in the control group (p < 0.05). Physically aggressive behaviors showed a decreasing trend for both groups. Scores of the Agitation Management Self-Efficacy Scale and its subscales increased significantly and continuously in the experimental group in comparison to those in the control group (p < 0.05). CONCLUSIONS: This home-based caregiver training program is helpful for decreasing problematic behaviors of elder people with dementia and it improves the caregiver's self-efficacy for managing problematic behaviors.

Aged↗

PubMed2003

Comparison of tension-free vaginal taping versus modified Burch colposuspension on urethral obstruction: a randomized controlled trial.

AIMS: To determine whether the tension-free vaginal tape (TVT) procedure affects the mechanics of voiding in women with genuine stress incontinence (GSI). METHODS: Between July of 1997 and July of 1999, 116 women with GSI in the absence of pelvic prolapse underwent a randomized controlled study of TVT vs. modified Burch colposuspension. The trial was conducted by using a standardized protocol, including strict criteria for excluding preexisting bladder outlet obstruction (BOO). Urodynamic studies including free flowmetry, filling (provocative) and voiding cystometry, and 1-hour pad test were performed before and at least 1 year after the operation. The Blaivas and Groutz nomogram was used as another criteria to assess the pre- and postoperative BOO. RESULTS: Eighteen women were excluded from the study as a result of having preexisting BOO and an additional 8 were lost to follow-up. The comparison between pre- and postoperative variables for each procedure revealed that maximal flow rate of noninvasive uroflowmetry was significantly lower after operation in both groups (P = 0.009, P = 0.010, respectively). Detrusor pressure at maximal flow and urethral resistance were significantly higher and micturition volumes significantly lower after operation in the Burch group (P < 0.001, P < 0.001, P = 0.029, respectively). The difference between pre- and postoperative distribution of the obstruction nomogram of the Burch group was significantly different (P = 0.023). CONCLUSIONS: Based on strict exclusion criteria for preoperative BOO, our findings strongly suggest that with a median 22 months (range, 12 to 36 months) of follow-up, a properly performed tension-free vaginal tape procedure does not cause urethral obstruction.

Adult↗

PubMed2003

Favorable influence of age on tumor characteristics of sporadic colorectal adenocarcinoma: patients 30 years of age or younger may be a distinct patient group.

PURPOSE: Age is reported as a risk factor for carcinogenesis, even though age can affect cancer behavior both positively and negatively. Young patients with colorectal cancer reveal different tumor characteristics than average-age and older-age groups, although few studies report the influence of age among the entire range of patient ages. The influence of age on clinicopathologic characteristics of sporadic colorectal cancer was analyzed. Whether an age group with distinct tumor characteristics was present was determined. METHODS: A total of 5,436 patients who underwent colectomy in a single institute within a seven-year period were studied. Data on clinical and histopathologic features of colorectal cancer were collected from the cancer registry and medical records. These characteristics were analyzed according to ten-year age groups. RESULTS: Eighty-three patients (1.6 percent) were 30 years of age or younger, whereas 285 (5.5 percent) were 31 to 40 years of age. Most patients (74.6 percent) were 51 to 80 years of age. The proportion of localized tumors (Dukes A and Dukes B) significantly increased as age increased, from 31.3 percent in the 30 years or younger age group to 49 percent in the 80 years or older group (P < 0.001). The proportion of poorly differentiated tumors tended to decreased as age increased (from 16.9 percent in the 30 years or younger group to 6.2 percent in the 80 years or older group; P = 0.009). A similar trend in the proportion of mucin-producing tumors was also observed (36 percent in the younger group vs. 7.5 percent in the older group; P < 0.001). There was no significantly different distribution of tumor locations among the different age groups. CONCLUSIONS: Age appears to favorably influence the clinicopathological characteristics of sporadic colorectal cancer. As age increased, the characteristics of tumor stage at diagnosis, tumor differentiation, and mucin production improved.

Adenocarcinoma↗

PubMed2003

Risk factors for descending aortic aneurysm formation in medium-term follow-up of patients with type A aortic dissection.

BACKGROUND: After surgery to repair a type A aortic dissection, most late complications and mortality result from descending aorta-related problems. This study was performed to determine the risk factors leading to descending aortic aneurysm formation and late mortality in patients undergoing the type A aortic dissection operation. METHODS: The medical records of patients who survived the operation for type A aortic dissection between 1984 and 1998 were reviewed. There were 144 patients (95 men and 49 women), ranging in age from 24 to 78 years (mean age, 52 years). Most patients were acutely ill, 15 patients were in shock, and 54 patients had cardiac tamponade at the time of the surgical procedure. One hundred thirty-seven patients had ascending aortic replacement only, and of the other 6 patients 2 had hemiarch and 4 had total arch replacement using the elephant trunk technique. The aortic valve was replaced in 23 patients, resuspended in 100, and untouched in 21. Twenty-four risk factors were evaluated in statistical analyses for the prediction of descending aortic aneurysm formation and 3-year mortality. Risk factors were investigated using univariate and multiple logistic regression and survival analyses. RESULTS: The 3-year, 5-year, and 8-year cumulative survival rates were 96.2%, 89.1%, and 80.0%, respectively. The 3-year, 5-year, and 8-year cumulative survival rates, free from descending aortic aneurysm formation or descending aorta operation, were 74.7%, 58.6%, and 43.0%, respectively. Multivariate analysis confirmed that patent false lumen and initial descending aortic diameter were statistically significant risk factors for descending aortic aneurysm formation. CONCLUSIONS: The medium-term survival rate of patients who received operations for type A aortic dissection was satisfactory, despite the high incidence of descending aortic aneurysm formation. The intimal entry site over the aortic arch that was resected during the first operation could decrease the patency rate of a false lumen over the descending aorta. In the absence of a patent false lumen over the descending aorta, the chance of descending aortic aneurysm formation or operation is lessened, and the late survival rate is increased.

Aged↗

PubMed2003

The XRCC1 399Gln polymorphism and the frequency of p53 mutations in Taiwanese oral squamous cell carcinomas.

DNA repair gene polymorphisms have been implicated as susceptibility factors in cancer development. It is possible that DNA repair polymorphisms may also influence the risk of gene mutation. The 399Gln polymorphism in the DNA repair gene XRCC1 has been indicated to have a contributive role in DNA adduct formation, sister chromatid exchange, and an increased risk of cancer development. Two hundred thirty-seven male oral squamous cell carcinomas (OSCCs) were included in a study to investigate the role of the XRCC1 194Trp, 280His, and 399Gln polymorphisms on p53 gene mutation. PCR-single-strand conformation polymorphism and DNA sequencing were used to analyze the conserved regions of the p53 gene (exons 5-9). The XRCC1 genotype was determined by PCR-RFLP. Nineteen (8.02%) of the 237 OSCCs had a Gln/Gln genotype. One hundred six (43.88%) of the 237 OSCCs showed p53 gene mutations at exons 5-9. The OSCC patients with a Gln/Gln genotype exhibited a significantly higher frequency of p53 mutation than those with an Arg/Gln and an Arg/Arg genotype. After adjustment for age, cigarette smoking, areca quid chewing, and alcohol drinking, the Gln/Gln genotype still showed an independent association with the frequency of p53 mutation (odd ratio, 4.50; 95% confidence interval, 1.52-13.36). The findings support the hypothesis that XRCC1 Arg399Gln amino acid change may alter the phenotype of the XRCC1 protein, resulting in a DNA repair deficiency. This study also suggests an important role for the XRCC1 399Gln polymorphism in p53 gene mutation in Taiwanese OSCCs.

Adult↗

PubMed2002

Small bowel intussusception in symptomatic pediatric patients: experiences with 19 surgically proven cases.

Nineteen cases of surgically proven symptomatic pediatric small bowel intussusceptions (SBI) were retrospectively reviewed. Clinical presentations included vomiting (89.5%), abdominal pain and/or irritable crying (89.5%), fever (52.6%), bloody stools (26.3%), palpable abdominal masses (15.8%), hematemesis (10.5%), jaundice (5.3%), and seizures (5.3%). The duration between symptom onset and hospitalization ranged between 20 and 336 hours (average 75.8 hours). Two patients with suspected appendicitis and small bowel obstruction were operated on promptly. Sonograms revealed target lesions (average diameter 2.9 cm) suggestive of intussusception in 13 out of 17 patients, with 10 lesions located in the paraumbilical or left abdominal regions. Barium enemas in 12 of these 13 patients demonstrated no colonic lesions. Diagnosis and surgery were delayed in 16 patients (average delay = 32 hours). The remaining 1 patient with positive sonographic findings underwent early surgery after computed tomographic (CT) confirmation of SBI. Surgery revealed ileoileal intussusceptions in 11 patients, jejunojejunal in 4, jejunoileal in 3, and duodenojejunal in 1. Eight patients had lead points. Bowel complications (ischemia, necrosis, or perforation) occurred in 8 patients. The duration between symptom onset and surgery in patients with bowel complications was significantly longer than for patients without complications (p = 0.0026). In conclusion, delayed diagnosis and surgical treatment in symptomatic pediatric patients with SBI were common, leading to a high rate (42%) of bowel complications. Sonographic demonstration of a 2-3 cm target lesion, especially if paraumbilical or left abdominal, is suggestive of SBI and may obviate the need for a barium enema; however, CT is helpful for confirming SBI. In symptomatic SBI, once diagnosed, early surgical referral is strongly recommended.

Adolescent↗

PubMed2002

A comparison of urethral pressure profilometry using microtip and double-lumen perfusion catheters in women with genuine stress incontinence.

OBJECTIVE: To compare urethral pressure profilometry measurements using microtip transducer and double-lumen perfusion catheters. DESIGN: Prospective study. SETTING: Tertiary referral urogynaecology unit. SAMPLE: Three hundred and ninety two non-pregnant women with various lower urinary tract symptoms. METHODS: Multichannel urodynamic investigations were performed using double-lumen perfusion catheters with external pressure transducers in 392 women. For those 301 (76.8%) diagnosed as having genuine stress incontinence, an investigation with microtip transducers followed. For data analysis, a mixed-effects model was used to evaluate changes in the urethral profilometry and an approach proposed by Bland and Altman was applied to access agreement between the two techniques. RESULTS: Of the 301 women with genuine stress incontinence, 272 were eligible for this study. In resting status, the differences between the two techniques were statistically significant (48.9cm H2O vs 73.4cm H2O, P = 0.0001) after adjusting for age. Moreover, the agreement study also confirmed that these two techniques do not agree sufficiently. CONCLUSION: Maximum urethral closure pressure obtained from the double-lumen catheter was significantly higher than that obtained from the microtip catheter. Use of the double-lumen catheter for the measurement of maximum urethral closure pressure can be considered a reliable technique since its reproducibility is as good as that of the microtip catheter. Therefore, the diagnosis of 'low pressure urethra' will be different between the two techniques.

Adult↗

PubMed2002

Dopamine transporter concentration is reduced in asymptomatic Machado-Joseph disease gene carriers.

UNLABELLED: Dopamine transporter (DAT) binding is decreased in Machado-Joseph disease (MJD) patients. To further investigate the DAT activity in asymptomatic MJD (aMJD) gene carriers, we performed this prospective study using (99m)Tc-TRODAT-1 ([(99m)Tc][2[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]-methyl](2-mercaptoethyl)amino]ethyl]amino]ethane-thiolato(3-)-N2,N2',S2,S2]oxo-[1R-(exo-exo)])) brain SPECT on 5 aMJD gene carriers, 10 age-matched MJD patients, and 10 age-matched healthy control subjects. METHODS: Brain SPECT images were acquired 4 h after intravenous injection of 925 MBq (25 mCi) (99m)Tc-T RODAT-1, which is known to bind specifically to the DAT on the nigrostriatal terminals. By fusing these SPECT images with a striatal atlas, obtained from MRI, binding of this tracer in the entire striatum was measured and the uptake values in bilateral striatal areas were compared between these 3 groups. RESULTS: The uptake values of the aMJD gene carriers (P < 0.001) and MJD patients (P < 0.001) displayed a significant reduction compared with those of the control subjects. The reduction was more severe in the MJD patient group (P < 0.05). Bilateral putamen-to-caudate ratios were significantly lower in the aMJD gene carrier and MJD patient groups (P < 0.001). The dopamine neuronal activity, as represented by the tracer binding, was more prominently affected in the putamen in these patients and gene carriers. CONCLUSION: (99m)Tc-TRODAT-1 brain SPECT is capable of detecting early alteration of dopamine neurons in the striatal region. Significantly, the results suggest that this impairment of presynaptic dopamine function actually occurs at an early stage, which was previously unrecognized in these aMJD gene carriers.

Adult↗

PubMed2002

Telomerase expression in benign and malignant skin neoplasms: comparison of three major subunits.

Telomerase is a specialized ribonucleoprotein polymerase that plays an important role in maintaining cellular immortality. The multifactorial activation of telomerase, a critical step in human carcinogenesis, is not fully understood. Many studies have shown increased telomerase activity in various skin cancers. To study the regulation of telomerase in cutaneous malignancy, we used the reverse transcription polymerase chain reaction (RT-PCR) with specific primers to analyze the mRNA expression of three major telomerase subunits: human telomerase RNA (hTR), telomerase-associated protein (TP1) and human telomerase reverse transcriptase (hTERT). Clinical skin specimens were taken from 62 Taiwanese patients with a variety of skin diseases, including five from normal skin, 27 from benign tumors, 17 from malignant tumors, six from premalignant tumors, and seven from inflammatory skin diseases. TP1 was detected in 61 of 62 specimens (98.4%) and hTR was found in 58 specimens (93.6%). hTERT was more often found in specimens from malignant and premalignant tumors (73.9%, 17/23) compared to those from benign tumors (7.4%, 2/27; p < 0.0001). None of the normal skin specimens showed hTERT expression. These results indicate that expression of hTERT, but not TP1 and hTR, is highly associated with cutaneous malignancy.

Adolescent↗

PubMedDate not supplied

Sudden cardiac arrest during computed tomography examination: clinical findings and "dense abdominal veins" on computed tomography.

We report imaging findings in five patients who had sudden cardiac arrest during contrast-enhanced computed tomography (CT). We observed strikingly dense abdominal veins, variable degrees of arterial enhancement, and poor abdominal visceral enhancement. Comparison with a control group of 30 patients revealed a statistically significant increase in mean enhancement of the abdominal veins (including the inferior vena cava, bilateral renal veins, and major tributaries of the hepatic vein) (Kruskal-Wallis test, P< 0.05). These patients lacked any clear cause of cardiac arrest, and the arrest may have been related to an adverse reaction to contrast medium. Despite resuscitation, two patients died and three convalesced. In summary, sudden cardiac arrest is characterized by "dense abdominal veins" on CT in the absence of the cardiac pump function. This effect was presumably the result of forced reflux and stagnation of contrast medium in the abdominal veins without any dilution with the circulating blood, leading to a markedly dense appearance of these venous structures.

Abdomen↗