Biomedical subjects

C J Lin

Publications and source records attributed to C J Lin.

At least 91 records · Page 5Linked to original sources

PubMed1997

Gait analysis of adult patients with complete congenital dislocation of the hip.

Comprehensive gait analysis is valuable in understanding the performance of patients with lower limb disorders. The gait pattern of adult patients with untreated congenital dislocation of the hip (CDH) has not yet been reported. We studied the gait pattern in nine women (mean age 31.4 years) with Crows group IV CDH. Six had unilateral and three had bilateral involvement. They were not treated during childhood and had no pain at the time of study. A control group comprised 15 normal female subjects of the same age group. Gait was studied using a motion-analysis system, force plateforms, and computer calculation during level walking. Common abnormal gait patterns seen in patients with both unilateral and bilateral CDH were slower walking velocity, which was due to a shorter stride length, less forward tilting of the pelvis, insufficient flexion, and excessive internal rotation of the hips. The patients with unilateral CDH had a shorter step length, lower pelvis, a lateral shift of the ground reaction force, decreased maximum adduction moments of the hip and knee on the diseased side, and increased maximum adduction moments of the hip and knee on the unaffected side. This asymmetry may have been due to leg length inequality. Thus, correlation of the leg length discrepancy may be important for unilateral CDH patients in improving their gait.

Adult↗

PubMed1996

Squalene inhibits sodium arsenite-induced sister chromatid exchanges and micronuclei in Chinese hamster ovary-K1 cells.

Arsenic, widely distributed throughout our environment, is a well-established human carcinogen. We report here that squalene, a natural fish oil, is a potential agent in the reduction of sodium arsenite-induced sister chromatid exchange (SCE) and micronuclei in Chinese hamster ovary (CHO-K1) cells. Squalene dose-dependently inhibited sodium arsenite-induced SCE. At the highest concentration (160 microM), squalene reduced the SCE frequency from 8.85 to 6.47 SCEs per cell which is very close to the background level (5.82 SCEs per cell). Sodium arsenite dose-dependently induces micronuclei in CHO-K1 cells, and squalene at 80 microM significantly inhibits arsenite-induced micronuclei. However, squalene did not eliminate the killing effects of arsenite on the cells and only slightly decreased intracellular accumulation of arsenic.

Animals↗

PubMed1996

Anaesthetic managements for conjoined twins with complex cardiac anomalies.

PURPOSE: To describe the perioperative assessment and anaesthetic management for surgical separation of three sets of conjoined twins with complex cardiac anomalies threatened with arterial desaturation and haemodynamic instability. CLINICAL FEATURES: Three sets of conjoined twins, one omphaloischiopagus, one omphalopagus, and one thoraco-omphalopagus, were considered for separation during the perinatal or infantile period. Preoperative functional evaluation including continuous pulse oximetry, capnography, and cardiac electrophysiological studies were considered to be as important as anatomical evaluation of the cardiac anomalies and cross-circulation by angiography in assessing the feasibility of surgical separation. Ipsilateral infusion of prostaglandin E1 and phenylephrine were applied to the cyanotic and healthy twins respectively, to restore arterial oxygenation intraoperatively and to avoid profound hypoxaemia. CONCLUSION: Surgical separation and anaesthesia should be well planned and rehearsed before clinical deterioration of the weaker twin. Aggressive pharmacological intervention and understanding of the cross-circulation pathophysiology is necessary to manage critical situations during surgical separation and in the postoperative period.

Anesthesia↗

PubMed1996

Ergonomic investigation of letter-carrier satchels: part I. Field study.

A field study was conducted to compare four satchels designed for the purposes of manually carrying and delivering mail. The satchels differed primarily in the presence/absence of a waist belt, the number and design of the shoulder strap(s) and the number of pouches. The evaluation consisted of questionnaires and interviews of slightly more than 300 letter carriers employed by the United States Postal Service. The questionnaires focused on 10 main areas of interest; ease of adjustability and handling, comfort, suitability and durability of materials, anthropometric applications, impact on other activities, ease of motion in retrieving mail, ease of motion in carrying the satchel, versatility of use in diverse climates, protection of mail from damage due to rain and snow, and defense against dog attacks. The primary conclusion was that the satchel with two shoulder straps and two pouches, which results in more symmetric loading than the other satchels, is the most desirable of the satchels tested. However, there are problems with the satchel that need to be addressed, such as concerns about the use of the satchel for defense from dog attacks.

Journal Article↗

PubMed1996

Ergonomic investigation of letter-carrier satchels: part II. Biomechanical laboratory study.

A biomechanical investigation of four satchels designed for the purposes of manually carrying and delivering mail was conducted. Twenty United States Postal Service carriers participated in the study. The satchels differed primarily in the presence/absence of a waist belt, the number and design of the shoulder straps, and the number of pouches. The biomechanical analyses were comprised of postural (shoulder and hip) deviation measurements, estimated compressive forces at the L5/S1 joint, soft tissue pressure on the shoulder, spinal torsion during mail retrieval, force distribution between the feet, and an anthropometric evaluation. The results indicated that a satchel with two shoulder straps and two pouches was more desirable than the single-pouch satchels from a biomechanics standpoint.

Journal Article↗

PubMed1996

Smoking, health knowledge, and anti-smoking campaigns: an empirical study in Taiwan.

This paper uses a measure of health knowledge of smoking hazards to investigate the determinants of health knowledge and its effect on smoking behavior. In our analysis, two equations are estimated: smoking participation and health knowledge. The simultaneity problem in estimating smoking behavior and health knowledge is also considered. Overall, the estimated results suggest that anti-smoking campaigns have a significantly positive effect on the public's health knowledge, and this health knowledge in turn, has a significantly negative effect on smoking participation. The health knowledge elasticities of smoking participation are -0.48 and -0.56 for all adults and adult males, respectively.

Adult↗

PubMed1996

Improvement of arterial oxygenation by selective infusion of prostaglandin E1 to ventilated lung during one-lung ventilation.

BACKGROUND: One-lung anesthesia provides a better surgical field for thoracic procedures but also impairs the arterial oxygenation and venous admixture. During one-lung ventilation, pulmonary vasoconstriction is assumed to be present within both ventilated and collapsed lungs. We propose that arterial oxygenation could be optimized by offsetting the vasoconstriction within the microcirculation of ventilated lung. METHOD: In an anesthetized dog model, incremental doses of prostaglandin E1 (PGE1) were selectively infused into the main trunk of the pulmonary artery of the ventilated lung after one-lung ventilation for 60 min (PGE1 group, n = 9). Arterial oxygenation and calculated venous admixture (Qs/Qt) was also assessed in a time-course control group (Control group, n = 5). During two-lung ventilation (FIO2: 0.66), arterial PO2 and venous admixture was 44.2 +/- 3.5 kPa and 10.7 +/- 2.3%, respectively. One-lung ventilation (FIO2: 0.66) with left lung collapsed reduced arterial PO2 to 11.6 +/- 1.7 kPa and increased venous admixture to 40.7 +/- 5.8% (P<0.001). Venous O2 tension also decreased from 6.3 +/- 0.7 kPa to 5.0 +/- 0.6 kPa with a slight increase in mean pulmonary artery pressure and pulmonary vascular resistance (P<0.05). RESULTS: During selective infusion of PGE1 at a dose of 0.04 to 0.2 mu g kg-1 min-1, there was a dose-dependent improvement in arterial PO2 with a parallel reduction of venous admixture during one-lung ventilation. Arterial PO2 increased to a maximum of 23.0 +/- 4.3 kPa, and the venous admixture decreased significantly to a minimum of 27.4 +/- 4.2% by PGE1 at a dose of 0.04-0.4 mu g kg-1 min-1 (P<0.01). PGE1 resulted in a small increase in cardiac output and decreases of pulmonary pressure and pulmonary vascular resistance at a relatively high dose of 0.4 mu g kg-1 min-1 during selective infusion (P<0.05). CONCLUSIONS: These results suggest that a selective pulmonary artery infusion of PGE1 to the ventilated lung within the dose range of 0.04-0.4 mu g kg-1 min-1 is practical and effective to improve arterial oxygenation and reduce venous admixture during one-lung ventilation.

Alprostadil↗

PubMed1996

Intestinal absorption studies on peptide mimetic alpha-methyldopa prodrugs.

Two dipeptide mimetic prodrugs, 1 and 2, and two tripeptide mimetic prodrugs, 3 and 4, of L-alpha-methyldopa were evaluated for intestinal absorption by in-situ single pass rat jejunal perfusion studies and by in-vitro uptake experiments in brush-border membrane vesicles (BBMVs) prepared from rat intestine. In the perfusion studies, compound 1 demonstrated a 3.5-fold increase in permeability (Pm* = 2.27) as compared with that of alpha-methyldopa (Pm* = 0.65), indicating that this prodrug was better absorbed in the intestine than its parent drug. Other prodrugs showed no significant improvement in intestinal permeability. The results correlated with the results of BBMV uptake studies. In the presence of an inward proton gradient, compound 1 showed Michaelis-Menton saturable kinetics of BBMV uptake with a low value of K(m) (0.06 +/- 0.13 mM) and a high value of Vmax/K(m)(36.38 nmol (mg protein)-1/30s mM-1) at a low concentration range and a linear uptake at high concentrations with Kd = 0.14 +/- 0.02 mM. Compounds 2 and 3 were mainly taken up in BBMVs via passive diffusion. Compound 4 was taken up in BBMVs basically via the carrier-mediated transport system, while the rate of uptake was much lower than that of compound 1. The uptake of compounds 1 and 4 was significantly inhibited by dipeptides L-Gly-L-Pro and L-Gly-L-Phe, and cephradine, a beta-lactam known to be transported via the dipeptide carrier system, indicating that both compounds were taken up in BBMVs via the H(+)-coupled dipeptide-mediated transport system. In contrast to the complicated uptake profile of alpha-methyldopa, the higher rate of BBMV uptake with less variation demonstrated on compound 1 suggested that the attached nonessential amino acid moiety, D-phenylglycine, is a feasible delivery tool in carrying the parent drug through the intestine.

Animals↗

PubMed1996

A fuzzy adaptive learning control network with on-line structure and parameter learning.

This paper addresses a general connectionist model, called Fuzzy Adaptive Learning Control Network (FALCON), for the realization of a fuzzy logic control system. An on-line supervised structure/parameter learning algorithm is proposed for constructing the FALCON dynamically. It combines the backpropagation learning scheme for parameter learning and the fuzzy ART algorithm for structure learning. The supervised learning algorithm has some important features. First of all, it partitions the input state space and output control space using irregular fuzzy hyperboxes according to the distribution of training data. In many existing fuzzy or neural fuzzy control systems, the input and output spaces are always partitioned into "grids". As the number of input/output variables increase, the number of partitioned grids will grow combinatorially. To avoid the problem of combinatorial growing of partitioned grids in some complex systems, the proposed learning algorithm partitions the input/output spaces in a flexible way based on the distribution of training data. Second, the proposed learning algorithm can create and train the FALCON in a highly autonomous way. In its initial form, there is no membership function, fuzzy partition, and fuzzy logic rule. They are created and begin to grow as the first training pattern arrives. The users thus need not give it any a priori knowledge or even any initial information on these. In some real-time applications, exact training data may be expensive or even impossible to obtain. To solve this problem, a Reinforcement Fuzzy Adaptive Learning Control Network (RFALCON) is further proposed. The proposed RFALCON is constructed by integrating two FALCONs, one FALCON as a critic network, and the other as an action network. By combining temporal difference techniques, stochastic exploration, and a proposed on-line supervised structure/parameter learning algorithm, a reinforcement structure/parameter learning algorithm is proposed, which can construct a RFALCON dynamically through a reward/penalty signal. The ball and beam balancing system is presented to illustrate the performance and applicability of the proposed models and learning algorithms.

Algorithms↗

PubMed1996

Two-stage cementless revision THR after infection. 5 recurrences in 40 cases followed 2.5-7 years.

We revised 40 infected hip prostheses in 40 patients as a two-stage procedure, including intravenous and oral antibiotics, gentamicin beads, and delayed cementless implantation of porous-coated THR. The duration of antibiotic treatment was 8 weeks. The interval from resection to reimplantation was, on average, 48 (8-108) weeks. 39 patients were followed, on average, 4 (2.5-7) years. 5 patients had a recurrent infection. In patients who did not have a recurrent infection, the Harris hip score exceeded 80 in 32 patients. Radiographically, femoral component migration of 2-6 mm was noted in 3 cases. The recurrent infection rate, and the functional and radiographic results are comparable with those obtained using a two-stage procedure with antibiotic cement.

Adult↗

PubMed1996

Non-O1 Vibrio cholerae bacteremia in patients with cirrhosis: 5-yr experience from a single medical center.

OBJECTIVES: To assess the clinical features and susceptibility of cirrhotic patients to non-O1 Vibrio cholerae bacteremia and to provide our therapeutic experiences in this rare and high lethal infection. METHODS: Twenty-eight blood culture isolates of non-O1 V. cholerae were identified by our clinical microbiology laboratory between July 1989 and June 1994. Patients with underlying cirrhosis and the aforementioned bacteremia were retrospectively reviewed. RESULTS: Twenty-one cirrhotic patients (16 male, five female; mean age, 50.9 yr; range 28-67 yr) were identified and classified as Child B (6 cases) and Child C (15 cases). Bacteremic episodes occurred most often from March to September. Seafood ingestion (seven cases) and seawater exposure (two cases) were risk factors, but nosocomial infections were also noted in six cases. Presenting symptoms and signs included ascites (95.2%), fever (81%), abdominal pain (52.4%), diarrhea (33.3%), and cellulitis with bullae formation (19%). Concurrent spontaneous bacterial peritonitis was determined in 10 cases, seven with positive ascites cultures. Antibiotic therapy (either cephalothin with gentamicin or ceftriaxone alone) cured most of the bacteremic episodes. The overall case-fatality rate was 23.8%, but 75% of the deaths were observed in patients with skin manifestation. CONCLUSIONS: Patients with decompensated cirrhosis are susceptible to non-O1 V. cholerae bacteremia and should not ingest raw seafood or expose skin wounds to salt water. A high index of suspicion and early administration of antibiotics may lower the mortality rate.

Adult↗

PubMed1996

Cementless reimplantation of hydroxyapatite-coated total hips after periprosthetic infections.

From February 1991 to July 1993, 26 hydroxyapatite (HA) coated total hips were implanted in 26 patients with infected hip prostheses. Seven were done as one-stage exchange arthroplasties and the other 19 were delayed reimplantations. Successful reimplantation was defined as a functioning hip without recurrence of infection at least 2 years after reimplantation. During a follow-up period of 25 to 54 months, 24 of the reimplantations were successful. Our success rate using the HA-coated prosthesis is similar to previous reports that used antibiotic impregnated bone cement. The HA method avoids the complications encountered with bone cement.

Adult↗

PubMed1996

Ventricular contractile interaction following coronary ligation in dogs.

BACKGROUND: Ventricular interdependence has already been reported. Diastolic ventricular interaction is well studied, but information is rare regarding systolic ventricular interaction and has shown only that maximal acceleration is a sensitive indicator of left ventricular performance. Hence, this study was conducted. METHODS: Eighteen mongrel dogs were anesthetized and two Millar catheters were advanced from the femoral artery and vein to the left ventricle and pulmonary artery for measurement of pressure, flow and velocity in each. Before and after ligation of the left anterior descending or right coronary artery, both ventricles, dP/dt max, maximum acceleration (MA), time to maximal acceleration (TTMA) were measured simultaneously and the percentage of area change and ventricular wall motion were recorded by two-dimensional echocardiography. RESULTS: The percentage of fraction area change decreased significantly when associated with decrease in dP/dt, maximal acceleration and TTMA in both ventricles. The parameters of contractility dP/dt and MA were marked and occurred earlier, after ischemia. In the litigation of LAD, infarct area involved the anteroseptal and apical region and both ventricular dysfunctions were noted. In the litigation of RCA when the interventricular septum motion was preserved, the RV hemodynamic had significant changes including dP/dt and MA, but there was insignificant change in LV. CONCLUSIONS: Ventricular interaction is less important than the direct effects of coronary occlusion on the myocardium, and the interventricular septum plays a relatively important part in ventricular interaction.

Animals↗

PubMed1996

[Endoscopic diagnosis and clinical experience of colonic tuberculosis].

From February 1979 to May 1994, 18 cases of colonic tuberculosis were detected by colonscopy at Chang Gung Momorial Hospital, Linkou Medical Center. There were 10 males and 8 females, with mean age of 43.6. In ten, the diagnosis was confirmed histologically or bacteriologically in colonic biopsy material and post-operated lymph nodes. The remaining 8 patients was suspected on colonoscopy, and had good response to antituberculous therapy. The major symptoms were abdominal pain (83%), diarrhea (67%), and body weight loss (61%). Average duration from symptoms to diagnosis was 4.1 months. Chest X-ray revealed active pulmonary tuberculosis in 14 of 18 patients (78%), 4 of 14 patients were military type. The colonic tuberculosis involved in ileocecal area in 6, ileocecum and contiguous colonic regions in 7, segmental colonic involvement in 4, and pancolitis in 1 patient. Multiple ulceration and ulcerohypertrophic lesions were the major colonoscopic findings. Typical caseating granuloma were found in 5 cases (36%) from colonoscopic biopsy, the other 5 from surgical resected specimens. Antituberculous therapy produced remarkable symptomatic improvement in all patients except 2 cases complicated with intestinal obstruction necessitating laparotomy. Colonoscopy with biopsy is a useful diagnostic tool in early diagnosis and avoiding unnecessary laparotomy in colonic tuberculosis.

Adolescent↗

PubMed1996

Prophylaxis against acid aspiration in regional anesthesia for elective cesarean section: a comparison between oral single-dose ranitidine, famotidine and omeprazole assessed with fiberoptic gastric aspiration.

BACKGROUND: Acid aspiration syndrome is still an important cause which contributes to maternal mortality in obstetric anesthesia. In this study, we compared famotidine, ranitidine, omeprazole with placebo for prophylaxis against aspiration pneumonitis in elective Cesarean section under regional anesthesia. METHODS: One hundred and sixty patients undergoing elective Cesarean section under spinal anesthesia were allocated randomly into four groups: Group P (n = 40) received placebo only; Group F (n = 40) received famotidine 40 mg Group R (n = 40) received ranitidine 300 mg; and Group O (n = 40) received omeprazole 40 mg. All drugs were given orally at least three hours before the patients entering the operating room. Gastric content was directly aspirated and measured respectively with a flexible fiberoscope under visualization and by a pH meter after delivery. RESULTS: Although these three drugs (F, R, and O) were all effective in controlling the secretion of gastric acid, from gastric analysis it was demonstrated that famotidine and ranitidine could be more defective to neutralize acidity than omeprazole (p < 0.05). Percentages of patients with pH < or = 2.5 in Groups P, F, R, and O were respectively 88%, 10%, 8%, and 21%, showing that the innate pH of gastric juice was far lower than expected. Patients receiving omeprazole in single oral dose regimen retained a greater gastric volume (> or = 0.4 ml/kg) than those who received famotidine or ranitidine (p < 0.005). From the criteria defining the patients "at risk" (pH < or = 2.5 and gastric volume > or = 0.4 ml/kg), it is speculated that all these three regimens could potentially reduce the incidence of patients with calculated risk. CONCLUSIONS: Our data demonstrated that parturients under regional anesthesia were at a higher risk of aspiration pneumonitis than generally thought. Single dose of ranitidine or famotidine administered orally three hours before surgery provided a more effective means to control and neutralize gastric secretion than omeprazole in parturients.

Administration, Oral↗

PubMed1995

Stereospecific blocking effects of naloxone against hemodynamic compromise and ventricular dysfunction due to myocardial ischemia and reperfusion.

Endogenous opioid peptides subserve regulatory roles in cardiovascular function and are released upon myocardial ischemia contributing to the development of ischemic arrhythmias and cardiogenic shock, which are reversed by the opioid antagonist naloxone. Since the hallmark of myocardial infarction is the impairment of hemodynamics and ventricular function, we evaluated further if blockade of opioids reverses the ischemia induced hemodynamic compromise, and if the effects are mediated by opioid receptors. Thirty-two mongrel dogs were anesthetized and artificially ventilated. Median thoracotomy was performed, the heart exposed, and the left anterior descending coronary artery isolated for subsequent occlusion and reperfusion. All cardiac parameters were recorded on an Electronics for Medicine recorder through the intracardiac catheters advanced from femoral vessels. Results indicate that naloxone significantly reversed the ischemic and reperfusion induced reduction in aortic, left ventricular and pulmonary arterial pressures, and left ventricular dp/dt. The inactive (+) stereoisomer of naloxone was without effect. These data demonstrate that opioids may have a role in the pathophysiology of myocardial infarction, mediated by opioid receptors, and provide new insight and strategies for the understanding and treatment of ischemic heart disease.

Animals↗

PubMed1995

Prenatal detection of limb defects after chorionic villus sampling.

Prenatal sonographic diagnoses of two cases of severe limb defects after first-trimester chorionic villus sampling (CVS) are presented. Pathological examination after elective termination correlated well with the prenatal sonographic findings. Although the relationship between CVS and limb defects remains controversial, careful ultrasound examination for possible limb defects in cases receiving CVS is recommended.

Adult↗

PubMed1995

Differential cytotoxicity of cadmium to rat embryonic fibroblasts and human skin fibroblasts.

In order to identify why cadmium is differentially toxic to humans and rats, we compared cadmium-induced cytotoxic responses in rat embryonic fibroblasts (REF) and human skin fibroblasts (HFW). According to the values of the lethal concentration 50% for cadmium, REF were about 13-fold more sensitive than HFW to cadmium acetate (1.5 vs 25 microM). Furthermore, progression of S phase cells was more severely delayed by cadmium in REF than in HFW. At doses that killed 90% of REF or HFW (5 or 50 microM, respectively), 50% of DNA synthesis was inhibited in REF, whereas DNA synthesis was not apparently inhibited in HFW. The differential sensitivity to cadmium could not be simply due to different basal levels of metallothionein, since the cellular metallothionein content in HFW was only 1.6 times that in REF, and metallothionein was apparently induced by cadmium in both cells with similar synthesis rates. Furthermore, elevation of cellular metallothionein levels by zinc sulfate pretreatment decreased cadmium toxicity in both cell types, but did not alter their relative sensitivity to cadmium. The differential sensitivity was also not due to differences in cadmium accumulation, since HFW accumulated more cadmium than REF after a 24-hr exposure to 1 or 5 microM cadmium acetate. Although most of the cadmium remained in the cytoplasm, the nuclei of REF contained 12-fold more cadmium than nuclei of HFW (1.31 vs 0.11 micrograms Cd/mg nuclear protein). Therefore, our results indicate that a high level of cadmium accumulation in nuclei of REF may be responsible for cell killing through breakdown of nuclear functions.

Animals↗