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Biomedical subjects

S C Huang

Publications and source records attributed to S C Huang.

At least 127 records · Page 7Linked to original sources
PubMed1998

Abnormal urodynamic findings after radical hysterectomy or pelvic irradiation for cervical cancer.

OBJECTIVE: To assess urodynamic study results in patients with cervical cancer who had received radical hysterectomy or pelvic irradiation or radical hysterectomy with pelvic irradiation. METHODS: Forty-two patients with stage IB cervical cancer after radical hysterectomy (group A), 11 patients at stage IB or IIA after pelvic irradiation (group B), 15 patients at stage IB or IIA after both radical hysterectomy and pelvic irradiation (group C) and 17 patients at stage IB before treatment (group D) as control were recruited for urodynamic examination. The evaluations for each case included a 20-min pad test, uroflowmetry, both filling and voiding cystometry, and stress urethral pressure profile. ANOVA method with Bonferroni test and Pearson chi2-test were utilized for statistical analysis. RESULTS: The mean ages in sequential groups A, B, C and D were 52.9 +/- 10.2, 62.5 +/- 13.5, 49.8 +/- 11.7 and 49.4 +/- 12.5 years (P = 0.02), respectively. The occurring frequency of either detrusor instability or low bladder compliance was 57%, 45%, 80% and 24%, respectively. Each group revealed decreased bladder capacity as 268.4 +/- 102.8, 164.1 +/- 62.9, 233.5 +/- 73.9 and 293.0 +/- 47.2 ml (P < 0.0001). However, the frequency of abdominal strain voiding was 100% in groups A, B and C as compared to 0% in group D (P < 0.01), and the frequency of abnormal residual urine (> 50 ml) was 41%, 27%, 40% and 24%. Although each case showed a poor pressure transmission ratio (< 100%), the frequency of positive pad test in each group was 81%, 46%, 100% and 18% (P < 0.001). The functional urethral length decreased in each group and was 2.6 +/- 0.8, 2.3 +/- 0.8, 2.5 +/- 0.8 and 2.9 +/- 0.6 cm, but there were no significant differences in maximal urethral pressure or urethral closure pressure among the four groups. CONCLUSIONS: Our data show that abnormal urodynamic findings pre-exist in patients with cervical cancer before treatment especially in bladder storing function, and that these findings may worsen, or that new abnormal findings may happen after radical hysterectomy or pelvic irradiation, or both.

Combined Modality Therapy↗
PubMed1998

VH usage and somatic hypermutation in peripheral blood B cells of patients with rheumatoid arthritis (RA).

The human antibody repertoire has been demonstrated to have a marked V-gene-dependent bias that is conserved between individuals. In RA patients, certain heavy chain V genes (VH) have been found to be preferentially used for encoding autoantibodies. To determine if such preferential use of VH genes in autoantibodies is associated with a general distortion of the V gene repertoire in RA patients, the VH composition of peripheral blood B cells was analysed among four RA patients and four age- and sex-matched healthy controls. Usage of individual VH genes (eight VH3 and three VH4 genes tested by hybridization with a set of gene-specific oligonucleotide probes) was highly biased among RA patients, but no evidence of a distortion in the bias was observed compared with healthy controls. However, the occurrence of somatic mutations in these VH genes (estimated by differential hybridization with motif-specific oligonucleotide probes targeted to CDR and FR of the tested genes, and by DNA sequence analysis) was strikingly different between patients and healthy subjects. The number of VH3 rearrangements that had accumulated somatic mutations and the number of mutations per rearrangement were significantly elevated in three of the four RA patients. A slight but not significant elevation in mutations among rearranged VH4 genes was also observed in these patients. These data suggest that although usage of individual VH genes among peripheral blood B cells is not affected by the disease, the autoimmune process may involve a significant fraction of the B cell compartment.

Antibodies↗
PubMed1998

Preliminary on-road measurement of the effect of oxygenated fuel on CO emissions near Las Vegas, Nevada.

A preliminary measurement of an oxygenated fuel effect for in-use vehicles travelling at freeway speed was conducted near Las Vegas, NV, in January 1991 and May 1992. The experimental design was based on two principal factors: (1) the large volume of traffic that visits Las Vegas from Southern California on three-day holiday weekends and (2) the fact that, at the time of the study, the Las Vegas area used oxygenated fuels in the winter and Southern California did not. Measurements were conducted at carefully selected sites 20 km southwest of Las Vegas near Sloan, NV, and were accomplished with the Fuel Efficiency Automoblie Test (FEAT) remote sensor developed at the University of Denver. The January 1991 measurements were made during the Las Vegas oxyfuel season, while the May 1992 control measurements were made outside the oxyfuel season. Over 24,500 individual CO concentrations were measured; registration data from over 5,500 of these vehicles were obtained from the license plate numbers. After corrections for differences in velocity and mean age, the Las Vegas outbound (oxyfuel) CO emissions on Monday morning of the January holiday weekend showed a difference of -18% +/- 11% compared to the inbound (non-oxyfuel) CO emissions on Friday evening preceding the holiday weekend.

Air Pollutants↗
PubMed1998

Arsenite inhibits mitotic division and perturbs spindle dynamics in HeLa S3 cells.

Arsenical compounds, known to be human carcinogens, were shown to disturb cell cycle progression and induce cytogenetic alterations in a variety of cell systems. We report here that a 24 h treatment of arsenite induced mitotic accumulation in human cell lines. HeLa S3 and KB cells were most susceptible: 35% of the total cell population was arrested at the mitotic stage after treatment with 5 microM sodium arsenite in HeLa S3 cells and after 10 microM in KB cells. Under a microscope, we observed abnormal mitotic figures in arsenite-arrested mitotic cells, including deranged chromosome congression, elongated polar distance of mitotic spindle, and enhanced microtubule immunofluorescence. The spindle microtubules of arsenite-arrested mitotic cells were more resistant to nocodazole-induced dissolution than those of control mitotic cells. According to turbidity assay, arsenite at concentrations below 100 microM significantly enhanced polymerization of tubulins. Since spindle dynamics play a crucial role in mitotic progression, our results suggest that arsenite-induced mitotic arrest may be due to arsenite's effects on attenuation of spindle dynamics.

Animals↗
PubMed1998

Effects of large neutral amino acid concentrations on 6-[F-18]Fluoro-L-DOPA kinetics.

6-[F-18]Fluoro-L-3,4-dihydroxyphenylalanine (FDOPA) has been used to measure the central dopaminergic function in many species, including humans and monkeys. For transport across the blood brain barrier (BBB), FDOPA competes with plasma large neutral amino acids (LNAA). In this article we evaluate the effects of normal physiological LNAA concentration variation on BBB transport (K1) and the FDOPA uptake measurement, Ki. We also investigate a method for reducing the dependency of FDOPA quantitation on LNAA. Adult vervet monkeys (Cercopithecus aethiops sabaeus, n = 19) were fasted overnight before FDOPA positron emission tomography scans. Blood samples were drawn for LNAA determination, metabolite analysis, and compartmental modeling. The estimated K1 and Ki were both negatively correlated with LNAA concentrations (r2 = 0.51 and 0.62, respectively). Using an adjustment to K1 and Ki based on these correlations, the LNAA dependency was reduced (SD of the data for K1 was reduced by 33%, for Ki by 40%). Experiments with amino acid loading on an additional six animals indicate that BBB transport can be described using Michaelis-Menten kinetics. Results show a clear dependence of FDOPA uptake on plasma LNAA concentrations, which can be removed to increase the precision of FDOPA quantitation.

Amino Acids↗
PubMed1998

Noninvasive quantification of the cerebral metabolic rate for glucose using positron emission tomography, 18F-fluoro-2-deoxyglucose, the Patlak method, and an image-derived input function.

The authors developed and tested a method for the noninvasive quantification of the cerebral metabolic rate for glucose (CMRglc) using positron emission tomography (PET), 18F-fluoro-2-deoxyglucose, the Patlak method, and an image-derived input function. Dynamic PET data acquired 12 to 48 seconds after rapid tracer injection were summed to identify carotid artery regions of interest (ROIs). The input function then was generated from the carotid artery ROIs. To correct spillover, the early summed image was superimposed over the last PET frame, a tissue ROI was drawn around the carotid arteries, and a tissue time activity curve (TAC) was generated. Three venous samples were drawn from the tracer injection site at a later time and used for the spillover and partial volume correction by non-negative least squares method. Twenty-six patient data sets were studied. It was found that the image-derived input function was comparable in shape and magnitude to the one obtained by arterial blood sampling. Moreover, no significant difference was found between CMRglc estimated by the Patlak method using either the arterial blood sampling data or the image-derived input function.

Brain↗
PubMed1998

Distribution volume of radiolabeled large neutral amino acids in brain tissue.

Variations in the cerebellum to plasma ratio at late times in 6-[18F]fluoro-L-DOPA studies are shown to be consistent with competitive binding of large neutral amino acids for a common transporter in the blood-brain barrier and the stability of brain tissue large neutral amino acid level in the presence of plasma level changes. The distribution volume of an inert large neutral amino acid can be estimated from plasma and tissue large neutral amino acid levels and apparent half-saturation concentrations (Km) of the transporter in the blood-brain barrier. Stability of brain large neutral amino acid levels is supported by literature findings and can be explained by high saturation of the large neutral amino acid transporter at physiologic conditions.

Amino Acids↗
PubMed1998

Generalized linear least squares method for fast generation of myocardial blood flow parametric images with N-13 ammonia PET.

In this paper, we developed and tested strategies for estimating myocardial blood flow (MBF) and generating MBF parametric images using positron emission tomography (PET), N-13 ammonia, and the generalized linear least square (GLLS) method. GLLS was generalized to the general linear compartment model, modified for the correction of spillover, validated using simulated N-13 ammonia data, and examined using PET data from several patient studies. In comparison to the standard model-fitting procedure, the GLLS method provided similar accuracy and superior computational speed.

Aged↗
PubMed1998

Characteristics and outcome of delirium in psychiatric inpatients.

Delirium, a transient organic psychiatric syndrome, is a common psychiatric diagnosis. It is associated with increased rates of morbidity and mortality in medical-surgical inpatients. There have been few reports describing the risk factors and prevalence of delirium among psychiatric inpatients. The purpose of the present study was to investigate the rate of delirium, the reasons for admission, the clinical features, the etiologies and the mortality during a 2 year follow-up in psychiatric inpatients admitted to a general hospital during a 3 year period. The results show that the rate of incidence of delirium in psychiatric and geriatric (age > or = 65 years) inpatients was 1.4 and 9.6% respectively. The most common cause of delirium was adverse effects of medication. The inpatient mortality (5.9%) was lower compared with reported mortality rates in medical-surgical inpatients. However, there was a high mortality rate during the 2 year follow-up period (39.4%), especially in older patients. The high mortality during follow-up stressed the importance of after-discharge care in these patients.

Adult↗
PubMed1998

Intrascleral dissemination of infectious scleritis following pterygium excision.

AIMS: To assess the clinical pictures, possible pathogenesis, management, and therapy of patients with infectious scleritis associated with multifocal scleral abscesses following pterygium excision. METHODS: The records of patients with infectious scleritis after pterygium excision who developed multifocal scleral abscesses presenting from 1988 to the end of 1995 were reviewed. Early culture of abscesses was performed, and topical, systemic antimicrobials, or both were given to all patients. Fourteen eyes were operated on in addition to antimicrobial treatment. RESULTS: The initial culture reports of scleral ulcers identified Pseudomonas species in 12 of these 18 patients, Aspergillus in one, Mycobacterium fortuitum in one, and mixed organisms in four. Subsequent abscess cultures were taken from 15 of the infected eyes, and revealed the same organism as the initial culture in 12. Associated complications included four serous retinal detachments, three choroidal detachments, two double detachments, five complicated cataracts, and four recurrences of the initial infection. Four eyes required eventual enucleation and 11 eyes regained useful vision. CONCLUSIONS: With subsequent abscess cultures proving to be the same organism as found in the initial ulcer, the abscess formation appears to represent intrascleral dissemination. Early diagnosis and appropriate, prolonged topical plus systemic antimicrobial treatment are essential to halt the progression of such severe infections.

Abscess↗
PubMed1998

Premenstrual asthma: report of a case with hormonal studies.

We report a 39-year-old female non-smoker who has history of asthma since the age of 29 and history of allergic rhinitis at age 13. No symptomatic characteristics of premenstrual tension were reported. Forced expiratory peak flow rate (PEFR) readings showed striking falls 24 hours before menses, with the peak flows dropping from a baseline of 350 L/min to 200 L/min. The patient received 10 mg prednisolone daily which was increased to 40 mg prednisolone in the menstrual week in an attempt to maintain a normal peak flow. Daily peak flow readings and every other day hormonal studies of progesterone and estrogen both demonstrated a positive correlation between the serum progesterone and the peak flow readings. The addition of intramuscular progesterone (75 mg daily) to the bronchodilators eliminated the premenstrual dips in peak flow, and daily doses of prednisolone were reduced to 5-10 mg. We suggest that a rapid fall in serum progesterone may play an important role in the pathogenesis of premenstrual asthma.

Adult↗
PubMed1998

Simultaneous measurement of myocardial oxygen consumption and blood flow using [1-carbon-11]acetate.

UNLABELLED: [1-Carbon-11]acetate has been used as a tracer for oxidative metabolism with PET. The aim of this study was to validate, in humans, a previously proposed two-compartment model for [1-11C]acetate for the noninvasive measurement of myocardial oxygen consumption (MVO2) and myocardial blood flow (MBF) with PET. METHODS: Twelve healthy volunteers were studied with [13N]ammonia, [1-11C]acetate and PET. Myocardial oxygen consumption was invasively determined by the Fick method from arterial and coronary sinus O2 concentrations and from MBF obtained by [13N]ammonia PET. RESULTS: Directly measured MVO2 ranged from 5.2 to 11.1 ml/100g/min, and MBF ranged from 0.48 to 0.88 ml/g/min. Oxidative flux through the tricarboxylic acid cycle, reflected by the rate constant k2, which correlated linearly with measured MVO2 [k2 = 0.0071 + 0.0074(MVO2); r = 0.74, s.e.e. = 0.015]. With this correlation, MVO2 could be estimated from the model-derived k2 value by MVO2 = 135(k2) - 0.96. The slope of this relationship was close to that previously obtained in rats and implies that the tricarboxylic acid cycle intermediate metabolite pool sizes are comparable. The net extraction (K1) of [1-11C]acetate, measured by PET, from blood into myocardium correlated closely with MBF by K1 = 0.15 + 0.73(MBF) (r = 0.93, s.e.e. = 0.033) and, thus, provided noninvasively obtainable measures of blood flow. CONCLUSION: The proposed compartment model for [1-11C]acetate fits the measured kinetics well and, with proper calibration, allows estimation of absolute MVO2 rather than only an index of oxidative metabolism. Furthermore, [1-11C]acetate-derived estimates of MBF are feasible.

Acetic Acid↗
PubMed1998

Nonspinal tuberculous osteomyelitis in children.

Tuberculous osteomyelitis is uncommon in children but its incidence seems to have increased in our hospital recently. From April 1984 to December 1994, we treated 12 children with this problem. Three cases were diagnosed in the first 7 years and nine cases in the latter 4 years. Primary spinal lesion was excluded. There were seven boys and five girls, with an average age of 2.4 years (range 1-4.5). Anatomic sites of involvement were distal femur in three patients, proximal tibia in three, foot in three, proximal femur in one, proximal humerus in one, proximal radius in one, distal radius in one, and rib in one. Except for one case of hip lesion, the most common symptom was localized swelling. Delay in diagnosis was 6.6 months on average. The diagnosis was confirmed bacteriologically or histologically in all patients after surgical debridement and curettage. Anti-tuberculosis (TB) drugs were administered for 6 months postoperatively. All patients were followed-up for an average of 3.8 years (range 2-8) with satisfactory healing of their tuberculous lesions. Two cases were complicated with physeal bar formation. One patient had residual flexion contracture of the knee. Although the mortality from TB has decreased in Taiwan, the frequently reported late cases of TB deserve attention. Physicians should be aware that TB remains an important cause of bone lesions. These lesions can be healed by combined therapy with surgical debridement and anti-TB medication for 6 months.

Age of Onset↗
PubMed1998

Clubfoot deformity in congenital constriction band syndrome: manifestations and treatment.

Clubfoot deformity associated with congenital constriction band syndrome (CCBS) has different characteristics than classic idiopathic clubfoot, and is more difficult to treat. We describe the manifestations, treatment, and outcomes of nine patients treated for 11 CCBS-associated clubfoot deformities between 1980 and 1993. All but one of these children had an abnormal gestational or neonatal history. From an assessment of the correctability of the deformity and the associated secondary changes, the clubfoot severities were all classified as grade B (intermediate). The constriction bands in eight clubfeet were classified as type 0 (5 feet), II (2), or III (1), according to the location and depth of the band. Band types in three feet were unclassified because the band release was performed at other hospitals. We released the bands before correcting the clubfeet in the two patients with type II bands. The five patients with type 0 bands received casting first but with poor response. All clubfeet were corrected surgically; the procedures were posteromedial release in 10 feet, split tibialis anterior tendon transfer in five, and lengthening of the Achilles tendon in three. At an average follow-up of 3.8 years, seven of the 11 clubfeet were classified as having good results and four as fair. Among the six clubfeet with constriction bands on the ipsilateral leg, five were classified as having good results and one as fair. Two of the five clubfeet without constriction bands on the ipsilateral leg had good results and three had fair results. The presence of a band did not influence the final outcome of the clubfoot deformity (p > 0.05). In the five patients with forefoot varus deformity due to peroneal weakness, tibialis anterior tendon transfer successfully corrected the deformity. All the clubfeet treated in this series were plantigrade after treatment and had satisfactory results.

Amniotic Band Syndrome↗
PubMed1998

Treatment of developmental dysplasia of the hip after failed open reduction.

It is difficult to obtain a good result by secondary open reduction if a primary open reduction for developmental dysplasia of the hip (DDH) fails. Complications such as avascular necrosis of the femoral head and subluxation of the hip are common. In this study, we retrospectively reviewed the causes of failure of primary open reduction and the final clinical and radiographic outcomes of 32 patients (34 hips) with DDH who underwent repeat open reduction and other procedures from January 1982 to December 1995. The ages of the patients at the time of the secondary operation ranged from 1.5 to 16.5 years (mean, 5.9 yr). The interval from the primary open reduction to the secondary procedure ranged from 3 days to 10 years (mean, 8.9 mo). In most cases (30 hips), the position of the redislocated femoral head was Tönnis grade 3 or 4. Avascular necrosis of the femoral head was evident in about half of the hips before the secondary open reduction. The most common cause of failure of the primary operation was a tight inferior capsule and transverse acetabular ligament, which blocked complete reduction. At a mean follow-up period of 42 months (range, 24-147 mo) after the secondary operation, the radiographic classification was Severin class 1 or 2 in 15 of the 34 hips, and Severin class 3 or worse in the remaining 19 hips. Clinically, according to the modified McKay criteria, 18 of the 32 patients (18 hips) had excellent or good results, and three patients (four hips) had poor results. In conclusion, the main cause of failure of the primary open reduction of DDH was technical error. We believe that detailed preoperative evaluation is critical for the success of primary open reduction of DDH.

Adolescent↗
PubMed1998

Pregnancy associated with gastric carcinoma.

Gastric cancer during pregnancy is very rare. We present the case of a 32-year-old woman, gravida 1 para 0, who suffered from advanced gastric cancer during pregnancy. Although the clinical symptoms of the tumor were evident early in the third trimester, the tumor was not diagnosed until 7 days postpartum, when it was too far advanced for curative resection. Only palliative procedures were carried out. The woman died of the cancer less than 3 months postpartum. Early diagnosis of this disease entity is often difficult and a poor prognosis invariably ensures, unless obstetricians maintain a high level of awareness. In pregnant patients with eccentric symptoms of the gastrointestinal tract that persist beyond the second trimester, further endoscopic evaluation should be considered. Occult blood in stool concomitant with elevated serum carcinoembryonic antigen concentration should be considered as an important indicator for thorough endoscopic investigation.

Adult↗
PubMed1997

Cut-off point of the Scoliometer in school scoliosis screening.

STUDY DESIGN: A large-scale study on school screening for scoliosis was conducted to assess the referral rate, prevalence rate, and positive predictive value using different angles of trunk rotation as criteria for referral. OBJECTIVE: To determine an ideal angle of trunk rotation cut-off point to be used for referral in school screening for scoliosis. SUMMARY OF BACKGROUND DATA: When using the Scoliometer (Orthopedic Systems, Inc., Hayward, CA) in school scoliosis screening, 5 degrees and 7 degrees angles of trunk rotation have been recommended as criteria for referral. Low positive predictive values and over-referral at these levels have been reported. METHODS: The Adams forward bend test and Scoliometer measurement were combined for school scoliosis screening in 33,596 girls from the fifth, sixth and seventh grades. Nurses were the primary screeners. Girls with trunk rotation angles of 5 degrees or more were referred for radiography. RESULTS: The referral rate was 5.2%. By selecting 6 degrees, 7 degrees, 8 degrees, 9 degrees or 10 degrees angles of trunk rotation as criteria for referral, the referral rate became 2.4%, 1.4%, 0.7%, 0.5%, or 0.3%, respectively. The prevalence rate for scoliosis equal to or larger than 10 degrees, 20 degrees, 30 degrees, or 40 degrees of the Cobb angle was 1.47%, 0.21%, 0.04% and 0.02%, respectively, by using a 5 degrees angle of trunk rotation as the criterion for radiography. The positive predictive value was 28.3% for scoliosis of 10 degrees or more, 4% for scoliosis of 20 degrees or more, 0.8% for scoliosis of 30 degrees or more, and 0.4% for scoliosis of 40 degrees or more with a 5 degrees angle of trunk rotation as the criterion for referral. By selecting angles of trunk rotation larger than 5 degrees as criteria for referral for radiography, the positive predictive value increased, but positive cases with larger Cobb angles also decreased markedly. CONCLUSION: The optimal cut-off point for referral when using the Scoliometer in school screening of scoliosis is still difficult to determine.

Adolescent↗