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Biomedical subjects

S Y Lin

Publications and source records attributed to S Y Lin.

At least 271 records · Page 15Linked to original sources
PubMed1990

Preliminary evaluation of the correlation between in vitro release and in vivo bioavailability of two aminophylline slow-release tablets.

An in vitro dissolution study has been carried out with a USP rotating paddle apparatus using the stepwise pH change method. The dissolution kinetics of two different matrix-type aminophylline slow-release (SR) tablets were compared. both aminophylline SR tablets show similar release rates and slow release behavior. The bioavailability of these two aminophylline SR tablets was also evaluated in eight healthy male Chinese volunteers and correlated with in vitro dissolution results by moment analysis. The preliminary results suggest that there is no evidence indicating that the two different matrix types of aminophylline SR tablets are not bioequivalent, and a good in vitro-in vivo correlation for these aminophylline SR tablets may therefore be presumed.

Aminophylline↗
PubMed1990

Assessment of combined thermoradiotherapy in recurrent of advanced carcinoma of the breast.

During 1980 to 1983, 40 patients with advanced or locally recurrent breast cancer were treated with the thermo-radiotherapy. Ten of these were primary cases and 30 recurrent. In 23 patients who had 2 to 3 lesions. Altogether there were 64 lesions treated. Combined thermo-radiotherapy was applied to the bigger lesions (42 in number) and irradiation alone to the small ones (22 in number). Average size of lesions treated with combined therapy was 38.7 cm2 and that by irradiation alone was 12.1 cm2. In 20 patients of this series previous irradiation (40-65 Gy) were given. Hyperthermia was given by using microwave 2450 MHz and 915 MHz, twice a week, 15-30 minutes following irradiation. Intratumoral temperature was maintained at 41-44 degrees C for 40 minutes. A average of 11.6 sessions of heat was given. Radiotherapy was given after conventional freactionation technic 2-2.5 Gy/day x 4-5/week to reach a total dosage of 20-80 Gy (average 47 Gy). Notwithstanding the size of tumor treated with combined therapy was 2 to 3 times larger than that treated by radiotherapy alone, the CR rate, of lesions after combined therapy was significantly better than radiation alone, 64.3% V.S. 36.4% (P less than 0.01). The authors believe that the optimal size of tumor for hyperthermia using microwave 2450 MHz or 915 MHz may be less than 5-6 in diameter.

Adult↗
PubMed1990

Evolutionary study on the Coxsackievirus A 24 variant causing acute hemorrhagic conjunctivitis by oligonucleotide mapping analysis of RNA genome.

The evolution of the variant of Coxsackievirus A 24 (CA 24 v) which causes acute hemorrhagic conjunctivitis was explored. Using 15 isolates obtained from Southeast Asia during the period 1970-1986, the genetic distance between isolates was estimated from pairwise comparison of nucleotide changes deduced from common spots on oligonucleotide maps of the isolates. From regression analysis of the genetic distance and the time of isolation of the isolates, the evolutionary rate of CA 24 v was estimated to be 3.44 x 10(-4)/nucleotide/month. The phylogenetic relationship of these isolates was explored using the neighbor-joining method and the modified unweighted pair group method using arithmetic averages (UPGMA). The phylogenetic tree constructed indicates that CA 24 v appeared from one focal place in July 1968 +/- 25 months, very close to the time of the first world epidemic of, then newly recognized, acute hemorrhagic conjunctivitis.

Asia, Southeastern↗
PubMed1990

Relationship between trunk muscle torque and bone mineral content of the lumbar spine and hip in healthy postmenopausal women.

The purpose of the study was to determine the relationship between trunk muscle strength and bone mineral density (BMD). Fifty-six postmenopausal women, aged 38 to 73 years, were examined. The BMD of lumbar vertebrae L2-4, the femoral neck, the Ward's triangle, and the greater trochanter was measured with dual-photon absorptiometry. Isometric and isokinetic torque and work measurements obtained on a trunk testing unit were used to assess trunk flexor and extensor strength. Correlation analysis demonstrated a statistically significant relationship between most trunk torque and work measurements and BMD. The trunk extensors generally provided higher correlations with BMD than did the trunk flexors, and the isokinetic extension torque values demonstrated higher correlations than the isometric extension values in every case. Linear backward-regression models, based on the subjects' weight and trunk flexor and extensor torque and work measurements, demonstrated multiple-correlation coefficients of .67, .58, .43, and .65 in predicting the BMD of the L2-4 region, femoral neck, Ward's triangle, and greater trochanter region, respectively. Estrogen therapy status did not affect the linear regression models. These data suggest a positive relationship in postmenopausal women between flexor and extensor torque values and BMD at the lower lumbar spine and proximal femur.

Adult↗
PubMed1990

Adjunctive surgery after chemotherapy for nonseminomatous germ cell tumors: recommendations for patient selection.

One hundred eighty-five patients who underwent surgery within 6 months of completing chemotherapy were identified from 360 patients with nonseminomatous germ cell tumors (NSGCT) treated with Memorial Hospital front-line cisplatin- or carboplatin-based combination chemotherapy protocols between 1979 and 1988. Clinical, pathologic, and radiologic features were correlated with the pathologic findings at surgery. The size of a residual retroperitoneal mass, the degree of shrinkage that occurred with chemotherapy, and the presence of teratomatous elements in pretreatment pathology specimens were each correlated with the pathologic findings of retroperitoneal resections after chemotherapy. Multivariable logistic regression analysis of those undergoing retroperitoneal resections identified the size and shrinkage of the residual mass and the prechemotherapy lactate dehydrogenase (LDH) and alphafetoprotein (AFP) levels as the best predictors of finding only necrotic debris. No factors could be found, however, that could selectively exclude patients who had residual viable malignancy or teratoma in the retroperitoneum. Of 39 patients with residual retroperitoneal masses measuring less than or equal to 1.5 cm in maximal diameter, three had residual malignancy and five had teratoma resected. No factors were identified for residual lung or mediastinal masses that could be used to select a group of patients who could safely avoid surgery. If serum markers have normalized after chemotherapy for NSGCT, resection of all residual abnormalities on imaging studies of the retroperitoneum, lungs, and mediastinum is recommended. In addition, retroperitoneal lymph node dissection (RPLND) is recommended for all patients with initial bulky metastases (greater than or equal to 3 cm in diameter) in the retroperitoneum, irrespective of the findings of postchemotherapy computed tomography (CT).

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Trimetrexate in prostatic cancer: preliminary observations on the use of prostate-specific antigen and acid phosphatase as a marker in measurable hormone-refractory disease.

Thirty-one patients with bidimensionally measurable hormone-refractory prostatic cancer received trimetrexate (TMTX). Serial values of prostate-specific antigen (PSA) and acid phosphatase (SAP) were correlated with response. Five patients (17%; 95% confidence interval, 3% to 30%) achieved a partial remission for a median of 3 months (range, 3 to 7.5 months). Marker levels showed large variations with no discernible patterns. Serial PSA and SAP in 19 patients with abnormal baseline values showed a correlation with measurable disease response in only 68% (13 of 19) and 47% (nine of 19) of patients, respectively. Values were then smoothed using an exploratory data analysis technique of running medians and averages. Trends in marker changes were much more apparent. Several "decision rules" were evaluated for use of markers as indices of disease progression. A 50% increase from the patient's minimum value in either PSA or SAP on two successive determinations correlated with progression in 90% of cases in this trial. TMTX has modest activity in prostatic cancer, and further trials are not warranted. Biochemical markers do not uniformly reflect disease activity in hormone-refractory disease, and changes in biochemical markers must be interpreted cautiously when used as the sole end point to assess efficacy in clinical trials.

Acid Phosphatase↗
PubMed1990

[Influence of plasma alpha-human atrial natriuretic polypeptide on natriuretic and diuretic effects in patients with nephrotic syndrome].

The physiological mechanism regulating secretion of alpha-human atrial natriuretic polypeptide (alpha hANP) was studied by measuring plasma alpha hANP (P alpha hANP) with radioimmunoassay during water immersion (WI). Twelve healthy volunteers and sixteen patients with nephrotic syndrome were immersed in water for 4 hours. During WI, alpha hANP level and urinary cGMP excretion (UcGV) increased significantly both in volunteers and patients, the urinary volume (UV) and urinary Na excretion (UNaV) also increased significantly. The mean peak values of alpha hANP and UcGV in volunteers were significantly lower than those in the patients, whereas the mean values of UV and UNaV in the former were significantly higher than those in the latter. The increase in alpha hANP level in volunteers correlated positively with the increase of UNaV, UV and UcGV during WI. The close correlations between the increased alpha hANP level and the increased UNaV, UV and UcGV was shown in the patients. These results suggest that alpha hANP is released into the circulation by acute central hypervolemia and plays a physiologically important role in maintaining water and electrolytes homeostasis in normal subjects and that the increased alpha hANP level in nephrotic syndrome makes compensatory regulation in water and electrolytes disorders.

Adolescent↗
PubMed1990

Role of endothelin in the pathogenesis of hypertension in spontaneously hypertensive and 2 kidneys 1 clip rats.

The plasma endothelin (ET) level in spontaneously hypertensive rats (SHR) and 2K1C hypertension animal models and its vasoconstrictive effect on renal and tail arteries were studied. The results demonstrated that there was no difference in plasma ET level between the hypertensive groups SHR, 2K1C, normotensive control groups Wistar Kyot (WKY) and Sprague Dawley (SD), while the vasoconstrictive effect of ET in SHR was more dominant than in WKY. The EC50 of the renal and tail arteries in SHR (0.8912 +/- 0.1662 x 10(-8) M, 0.6103 +/- 0.0878 x 10(-8) M) was apparently lower than that in WKY (1.77 +/- 0.2991 x 10(-8) M, 1.2267 +/- 0.2502 x 10(-8) M, P less than 0.05), but no difference was found in 2K1C and SD rats. The four groups of animals exhibited no difference of such effects as response to norepine-phrine (NA). The findings suggested that the increased arteriole sensitivity to ET be an important factor in the pathogenesis of hypertension in SHR.

Animals↗
PubMed1990

Effect of obstructive jaundice on renal Na-K ATPase activity and ATP contents, their response to E. coli or endotoxin and effect of 1-6 fructose diphosphate.

A two-week bile duct ligation (BDL) in Sprague-Dawley (SD) rats raised the serum billirubin level and decreased the mean arterial blood pressure and renal cortical ATP contents compared with those in sham-operated (SO) rats (3.6 +/- 1.15 mg% vs 0.54 +/- 0.36, P less than 0.001; 69 +/- 24 mmHg vs 86 +/- 21, P less than 0.05; 3.72 +/- 0.86 x 10(-10) mol/mg tissue vs 7.27 +/- 0.18, P less than 0.05). No difference could be found in the medullary ATP contents (8.42 +/- 2.20 vs 8.70 +/- 2.80, P = NS). In SO rats, injection of endotoxin (0.7 mg/kg BW) and E. coli (3.1 x 10(5) bacteria/100 g BW) reduced cortical ATP content to 1.86 +/- 0.97 and 1.30 +/- 0.47 (P less than 0.001), and medullar ATP to 1.33 +/- 0.31 and 2.12 +/- 0.46 (P less than 0.001) respectively. In BDL rats, the same treatment led to further decrease in cortical ATP to 1.25 +/- 0.40 and 0.62 +/- 0.20, medullary ATP to 0.97 +/- 0.41 and 1.64 +/- 0.83 (P less than 0.001). Basal Na-K ATPase activity in BDL is the same compared with that in SO both in the cortex (2.85 +/- 2.2 mumol/mgpr/h vs 2.19 +/- 0.75; P = NS) and medulla (2.79 +/- 1.83 vs 3.05 +/- 1.38; P = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1990

Intrauterine neuromuscular blockade in fetus.

Antenatal intrauterine fetal therapy has now become the target of numerous invasive diagnostic and therapeutic maneuvers. Fetal motion during intrauterine fetal therapy not only makes these procedures technically more difficult but also increases the likelihood of trauma to the umbilical vessels and the fetus. Combination of high doses of sedatives, tranquilizers, and narcotics rarely results in adequate suppression of fetal movement. Such medication puts the mother at risk of respiratory depression, regurgitation and aspiration. The use of pancuronium or atracurium to temporarily arrest fetal movement in ten fetus is reported. After an initial ultrasound assessment of fetal lie, placental location, and umbilical cord insertion site, the fetal weight was calculated by the ultrasound parameters of biparietal diameter and abdominal circumference. Under ultrasound guidance, we injected pancuronium 0.15 mg/kg or atracurium 1.0 mg/kg using a 23-gauge spinal needle into the fetal gluteal muscle. Short-term paralysis of the fetus was induced in all cases. Fetal movement stopped by sonographic observation within 5.8 +/- 2.3 min in the pancuronium group and 4.7 +/- 1.8 min in the atracurium group. Fetal movements returned both to maternal sensation or ultrasonic observation by 92 +/- 23 min in the first group and 36 +/- 11 min in the second group. No adverse effect of the relaxant has been observed in any of the mothers. There was no evidence of local soft tissue, nerve or muscle damage at the site of injection on initial examination of the neonates after delivery. The use of neuromuscular relaxant in fetus was a safe and useful method.

Atracurium↗
PubMed1990

Correction osteotomy of flexion deformity of cervical spine in ankylosing spondylitis--a case report.

It is well known that severe flexion deformities of the spine may occur in patients suffering from ankylosing spondylitis. The prevention of these deformities by early recognition of the disease process should be the main aim of the medical profession in handling patients with specific spinal involvements. Yet, we still see all too often patients with advanced kyphotic deformities of the trunk who are very grossly disabled and thus present a major problem to definitive surgical correction of their deformities. Correction of rigid kyphosis by establishing a compensatory lordosis can be carried out in the lumbar or cervical area. Surgical intervention in the cervical region enables the chin to be lifted off the sternum, but great care has to be taken of the relatively bulky spinal cord, which practically fills the spinal canal. Excessive correction runs the risks of fatally damaging the nerves and vertebral vessels. Therefore, most centers perform correction osteotomies of the cervical spine progressively, with day-by-day adjustment of the external fixators. We present a case of cervical osteotomy in which, under local anesthesia and with the aid of S.S.E.P., cervical kyphosis was corrected by a one-stage procedure. The results and difficulties are described here-in.

Adult↗
PubMed1990

Suppression of hemodynamic change before extubation--lidocaine through modified endotracheal tube.

Twenty females, aged 31 to 49 years, scheduled for abdominal total hysterectomy were randomly divided into two groups in this study. An epidural catheter was placed at T11-12 before general anesthesia. All patients receive the combination of epidural anesthesia and general anesthesia for the operation and relief of pain postoperatively. The modified endotracheal tube we used is shown in Fig. 1. For patients in group I (Lidocaine group), 2 mL 4% lidocaine solution was injected through the catheter to desensitize the tracheal mucosa around the cuff after the surgeon had removed the uterus. In group II (Control group), no special management was made. All patients were not extubated until they were considered to be awake. Systolic blood pressure at three and one minute before extubation and pulse rate recorded at one minute before extubation showed in patients of group I were statistically smoother than those recorded in group II (p less than 0.01). All patients had gag reflex just after awake extubation.

Adult↗
PubMed1990

[Infusion speed as a factor to influence the analgesic level of spinal anesthesia--hypobaric solution of tetracaine].

In spinal anesthesia, as known, the injection speed of local anesthetic drug is a factor which influences the analgesic level. For study it, automatic infusion apparatus was available to control as 5 kinds of infusion speed (0.02-0.51 mL/s), and 78 patients were divided into 6 groups. The results of the painless level was discussed by T-test and distribution analysis (F-test). The mean of painless level in each group was found to be no significant difference as discussed by T-test. But the largest distribution was found in the group of 0.04 mL/s, and high analgesic level as rise up to T6 was occasionally found in groups of 0.04 mL/s & 0.02 mL/s. It means, the infusion speed is not an important factor, but extremely slow infusion is more dangerous than high speed infusion, which will take a risk of high level spinal anesthesia.

Adult↗
PubMed1990

Epidural anesthesia for spine surgery.

Over the last 2 years, the authors have had experience with epidural anesthesia for a variety of spine operations in 20 patients. It is proved to be safe, reliable, and effective. Perioperative complications were minimal and could be easily treated. No patient had a new neurologic deficit as a result of the epidural technique. Thus, epidural anesthesia should not be excluded from the anesthesiologist's consideration simply because of the presence of spine disease or neurologic deficit.

Adult↗
PubMed1990

Effect of beta-cyclodextrin on the in vitro permeation rate and in vivo rectal absorption of acetaminophen hydrogel preparations.

The amounts of beta-cyclodextrin and hydroxyl propyl methyl cellulose (HPMC) affecting the in vitro permeation rate of acetaminophen containing in both aqueous solutions and HPMC hydrogel preparations through the dialyzer tubing and isolated rat rectum were investigated. The partition coefficient of acetaminophen with or without beta-cyclodextrin in water/n-octanol system was also studied. In vivo absorption experiments of these test formulations were carried out by rectal administration in rats. The results indicate that the concentrations of beta-cyclodextrin and HPMC used decreased the amount permeated of acetaminophen from both test formulations. The more the amount of beta-cyclodextrin or HPMC the slower the permeation rate of acetaminophen. The permeation rate of acetaminophen through the dialyzer tubing was higher than that of acetaminophen through the isolated rat rectum. The result also shows beta-cyclodextrin and HPMC markedly reduced the in vivo bioavailability of acetaminophen from both test formulations. The lower partition coefficient and the higher hydrophilic properties of beta-cyclodextrin inclusion complex, and the higher viscosity of HPMC hydrogel matrix might be responsible for decreasing the in vitro permeation rate and depression of in vivo rectal absorption of acetaminophen. The in vitro permeation data was well correlated with in vivo absorption results, suggesting that the in vitro permeation study regardless of the dialyzer tubing method or the isolated rat rectum method might be used to estimate the in vivo rectal absorption of acetaminophen.

Acetaminophen↗
PubMed1990

Comparison of lower concentrations of lidocaine to suppress bucking before extubation during recovery of general anesthesia.

Thirty females, aged 25-50 years old, scheduled for abdominal total hysterectomy were randomly divided to two groups. For patients in group I, 2 mL 1% lidocaine solution was injected through the catheter on the tube to desensitize the trachea while surgeon started to close the peritoneum. In group II, 2 mL 2% lidocaine was used. The peak cuff pressures generated in the awakening group I patients were 49.0 +/- 2.5 cmH2 O (mean +/- SD) which shows greater than that in group II (27.9 +/- 7.2 cmH2 O), p less than 0.01. Bucking before awakening was also evaluated clinically. One hundred % (15/15) in group I patients bucked compared with 13.3% (2/15) in group II patients (p less than 0.01). Gag reflex was preserved in all patients and none suffered from aspiration postoperatively. Intratracheal administration of two mL 2% lidocaine through the catheter of modified endotracheal tube showed significant effect for suppressing bucking during recovery of general anesthesia.

Adult↗
PubMed1990

Is it necessary to rotate the epidural needle to obtain successful sacral segment block?

The effect of rotating the level of touhy needle to obtain successful sacral blockade was controversial. During the rotation, dural puncture was reported by some studies. In our study, we divided forty patients into two groups randomly. They all belonged to ASA I-II, receiving epidural needle insertion at L 2-3 epidural space, before epidural catheter was inserted. Total of 10 mL of 2% xylocaine was injected into the epidural space. In group A, the level of Touhy needle was pointed upward, that is, parallel to the ligament flavum. In group B, the level was pointed caudally. We determined the cutaneous extension of loss of cold sensation by using a swab of cotton wool soaked with alcohol 15 min and 25 min after the test injection. Our result showed no different in loss of cold sensation in sacral area between these two groups. So we concluded that there is no need to rotate the epidural needle for sacral blockade.

Adult↗