Biomedical subjects

L S Lin

Publications and source records attributed to L S Lin.

At least 55 records · Page 3Linked to original sources

PubMed1995

Randomized trial of loperamide versus dose escalation of octreotide acetate for chemotherapy-induced diarrhea in bone marrow transplant and leukemia patients.

This study compares maximal daily doses of loperamide to escalating doses of continuous intravenous (CI) octreotide acetate in bone marrow transplant (BMT) and leukemia patients. Following chemotherapy, BMT and leukemia patients who developed > or = 600 ml of stool volume in a 24-hr period were randomized to receive loperamide 4 mg po q6h or octreotide 150 micrograms mixed in hyperalimentation solution or normal saline and administered CI. Patients were assessed at 48 hr intervals for decrease in stool volume from baseline. Complete response (CR) was defined as > or = 50% from baseline stool volume (BSV). Patients receiving octreotide who did not achieve a CR at 48 hr were dose escalated by doubling the dose to a maximum of 2,400 micrograms with evaluations at 48 hr intervals. Patients receiving loperamide who did not achieve a CR at 48 hr had treatment discontinued. A total of 36 patients were enrolled in the study. Of these, all were evaluable for intention to treat, and 31 were evaluable for initial response. Based on intent to treat at the initial 48 hr, patients receiving loperamide had a higher complete response rate (86% vs. 45%, P = 0.033) than did those who received octreotide. By treatment analysis (patients who actually received the drug), patients receiving loperamide had a higher complete response rate (92% vs. 56%, P = 0.0448) than did those who received octreotide at the 150 micrograms dosage level. Additional octreotide patients eventually achieved a CR at a higher dosage level (78%). Loperamide at maximal doses of 4 mg po q6h is more effective than octreotide 150 micrograms CI in treating diarrhea following chemotherapy in BMT and leukemia patients. Higher doses of octreotide may be required in a significant number of patients not responding to lower doses.

Adult↗

PubMed1995

Expression of the Epstein-Barr virus DNA polymerase in Escherichia coli for use as antigen for the diagnosis of nasopharyngeal carcinoma.

Epstein-Barr virus (EBV) encoded DNA polymerase (POL) was cloned and over-expressed in Escherichia coli. Western blot analysis confirmed the presence of antibody to this POL protein in sera from nasopharyngeal carcinoma (NPC) patients. By Western blot analysis, moderate to high concentration of IgG POL-specific antibodies were present in 43 of 48 NPC sera and only 4 of 48 healthy, seropositive controls. The POL-specific IgG antibodies appear as early as stage I of NPC, suggesting that the recombinant POL protein can be a useful diagnostic marker for early diagnosis of the disease. It was also found that human sera containing high titer of cytomegalovirus (CMV) antibodies or herpes simplex virus type 1 (HSV-1) antibodies did not cross-react with the recombinant EBV POL, despite the homology shared by DNA polymerase proteins of these viruses.

Amino Acid Sequence↗

PubMed1995

Expression of human gonadotropin-releasing hormone receptor gene in the placenta and its functional relationship to human chorionic gonadotropin secretion.

Placental GnRH is one of the potential paracrine regulators of hCG secretion from the trophoblasts during pregnancy. Maternal serum hCG levels exhibit an exponential rise during the first 6 weeks of pregnancy, peak at 9-10 weeks, decline to a nadir at 20 weeks, and remain at low levels during the rest of pregnancy. However, the placental content of GnRH does not parallel the time course of hCG secretion, and GnRH messenger ribonucleic acid (mRNA) levels in the placenta remain unchanged during pregnancy. These data do not conform with a simple paracrine mechanism of GnRH as a regulator of hCG secretion. We, therefore, examined the potential variation in GnRH receptor gene expression in the placenta, which may account for the GnRH-mediated dynamic pattern of hCG secretion during gestation. First, we established a functional relationship of GnRH and hCG secretion. Using a placental explant culture system, a dose-response effect of hCG secretion was observed in the placental explant at 9 weeks when treated with GnRH ranging from 10(-9)-10(-7) mol/L. The effect of GnRH was completely blocked by a GnRH antagonist (Nal-Glu). The relative responsiveness of hCG secretion to GnRH stimulation at 10(-7) mol/L was further evaluated in placental explants at 6, 9, and 40 weeks gestation. Whereas the 9-week placenta showed a maximal response (> 300%) relative to the 6-week placenta, there was no response in term placenta. Again, the effects of GnRH on hCG secretion were blocked by Nal-Glu, supporting a receptor-mediated event. Localization of mRNA encoding human GnRH receptor in human placenta at 6, 9, 12, 20, and 40 weeks gestation was established by in situ hybridization. The mRNA signals were present in both cytotrophoblast and syncytiotrophoblast cell layers. Signal intensities varied with gestational ages and were abundant at 6 weeks, peaked at 9 weeks, declined at 12 and 20 weeks, and were undetectable at term. The present study demonstrates, for the first time, that GnRH receptor mRNA is expressed in both cytotrophoblasts and syncytiotrophoblasts and exhibits changes paralleling the time course of hCG secretion during pregnancy. These data provide a mechanistic understanding that the paracrine/autocrine regulation of hCG secretion by placental GnRH is mediated through an increase followed by a decline in GnRH receptor gene expression from the first trimester to term placenta.

Chorionic Gonadotropin↗

PubMed1994

Continued survival of older hemodialysis patients: investigation of psychosocial predictors.

This study investigated whether social and/or psychologic factors help to predict older dialysis patients' continued survival. A stratified (by race and sex) random sample of patients aged 60+ years was selected from the ESRD Network census of all patients in that age category residing in a single southeastern state (Georgia) and receiving chronic dialysis as of November 1987; personal interviews with patients were completed in 1988. This analysis includes 287 patients (mean age, 69 years) receiving outpatient hemodialysis for whom primary cause of renal failure and functional status data were complete. Patient tracking and vital statistics data determined that 49% of the sample survived as of October 31, 1990. Study variables included demographic, dialysis, health status, social situation, and psychologic outlook variables reported at the patients' 1988 interviews. Log rank tests showed univariate associations between patients' continued survival and race/gender, recovery time following dialysis treatments, cardiovascular co-morbidity, exercise activity score, freedom from health limitation of daily activity, functional status, leisure activity score, self-rated health status, overall life satisfaction, depression, and public religiosity. The Cox proportional hazards model was fit to the data, with continued survival from the time of the 1988 interview as the dependent variable. There was a significantly increased mortality risk for white men relative to the other race/gender groups and for patients reporting severely impaired functional status at the 1988 interview. With functional status in the model, no other social or psychologic variables were significant predictors of mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Comparable safety of blood collection in "high-risk" autologous donors versus non-high-risk autologous and directed donors in a hospital setting.

The safety of autologous blood donation by "high-risk" patients (those with some preexisting medical conditions) has been questioned. The authors reviewed 1393 consecutive blood donation records (207 high-risk autologous [HRA], 665 non-high-risk autologous [NHRA], and 521 directed donors [DD]) to determine the safety and outcome of blood donation by HRA patients as compared with other donors at their center. The HRA group included patients with a history of significant coronary artery on cerebral vascular disease, recent seizures, cardiac arrhythmia, chronic heart failure, valvular or congenital heart disease, symptomatic dyspnea, insulin-dependent diabetes and/or current therapy with two or more antihypertensive medications. Those designated NHRA were all other autologous donors; DD met all criteria for homologous donation. Donor characteristics including predonation hematocrit, pre- and postdonation mean arterial pressure and heart rates were similar in all groups. Eight HRA donors (3.9%) had reactions, compared with 21 NHRA (3.2%) and 23 DD (4.4%), a difference that was without statistical significance. The reaction rate in all autologous donors (HRA and NHRA) was 3.4%. No differences in symptoms reported, hemodynamics or reaction severity were observed among the three groups (P > .05). A multiple logistic regression was performed within and among the groups with the risk factor categories listed above and medication classes including beta blockers, cardiac glycosides, calcium-channel blockers, antihypertensive agents, nitrates, and antiarrhythmic agents (chi 2 = 14.9; P = .0006). Only first-time donation (P = .0001) and cardiac glycoside usage (P = .04) were positively associated with an untoward reaction. The authors conclude that donation by HRA donors is at least as safe as that by donors who meet homologous donation criteria in their population and setting.

Adult↗

PubMed1994

[Moyamoya disease in Taiwan].

From January 1978 to December 1993, 73 patients with moyamoya disease were collected from seven neurological centers in Taiwan. The annual incidence of this disease in Taiwan is 0.024 per 100,000 population. There were 33 males and 40 females. The ages ranged from 2 to 62 years with a peak incidence in the 31 to 40 year age group (18 cases). Cerebral infarction occurred in 16 out of 19 juvenile patients (84.2%); by contrast, only 19 out of 54 adult patients (35.2%) presented with infarction. Hemorrhagic strokes were more frequent in adult patients. Computed tomographic scans following stroke showed cerebral infarction in 35 cases, ventricular hemorrhage in 21 cases, intracerebral hemorrhage in 11 cases and pure subarachnoidal hemorrhage in 6 cases. The most frequent initial symptom was motor disturbance (58.9%), followed by headaches (49.3%), and impaired consciousness (34.2%). Compared with reports from Japan, this survey showed a lower incidence of moyamoya disease in Taiwan.

Adolescent↗

PubMed1994

Analysis of variations in mortality rates with small numbers.

OBJECTIVE: We present a Monte Carlo technique to evaluate if observed mortality rates differ from model-predicted rates for situations when the number of deaths is small. DATA SOURCES: We used Medicare hospital claims and model-predicted mortality rates from the Health Care Financing Administration (HCFA) for the 169 acute care hospitals in Georgia. The HCFA data provided model-predicted mortality rates at 30 days postadmission for 17 conditions and procedures of interest. The model-predicted rates calculated by HCFA were adjusted for patient factors, including demographic characteristics, principal diagnosis, and comorbidities. STUDY DESIGN: We test the hypothesis that model-predicted 30-day mortality rates at the 169 hospitals differ significantly from the observed 30-day mortality rates. Our approach uses a test statistic that resembles a chi-square statistic, and Monte Carlo simulations to estimate the distribution of the test statistic under the null hypothesis of no differences between the observed and predicted rates. We illustrate the method using two conceptually similar simulation models. We use results of the simulations to estimate p-values and compare these results with p-values associated with the nominal chi-square distribution. DATA EXTRACTION METHODS: We extracted 30-day observed and predicted mortality rates for Medicare beneficiaries for federal fiscal year 1990 for 17 conditions and procedures of interest. PRINCIPAL FINDINGS: If the number of deaths in some hospitals is small, p-values calculated using the nominal chi-square distribution can be misleading, thus supporting the usefulness of our simulation method. CONCLUSIONS: The Monte Carlo simulation is an appropriate approach to the analysis of hospital mortality or small area analysis for situations in which the number of deaths is small.

Analysis of Variance↗

PubMed1994

Subarachnoid glioependymal cyst: a case report.

A case of subarachnoid glioependymal cyst in a newborn baby is reported. An intracranial cystic lesion was found at 32 weeks of gestation by ultrasonography. The infant was born with an enlarged head and impaired auditory evoked potential (AEP). Computed tomography and magnetic resonance imaging revealed a large homogeneous cystic lesion over the left cerebral convexity with displacement of the left hemisphere to the right. Craniotomy was performed, with removal of the cystic wall and insertion of a cystoperitoneal shunt. Postoperatively, improvement was noted on clinical examination and ultrasonography. Previously, only one such case, treated perinatally, has been reported.

Arachnoid Cysts↗

PubMed1993

Antagonistic effects of lesions of paramedian reticular nucleus on amphetamine-induced locomotion and striatal dopamine release in rats.

Systemic administration of amphetamine (1.25 mg/kg) produced increases of locomotion (including horizontal motion, vertical motion, and total distance travelled), elevations of turnings (including both clockwise and anticlockwise) and inhibition of postural freezing in freely moving rats. All the afore-mentioned activity measures induced by amphetamine were suppressed following electrolytic lesions of the paramedian reticular nucleus (PRN) in rat medulla. In addition, the spontaneous level of either the locomotor activity, the direction of turnings, or the postural freezing were slightly but significantly affected by the PRN lesions. In vivo voltammetric data revealed that amphetamine administration greatly enhanced the striatal dopamine release. Furthermore, the enhanced dopamine release in corpus striatum produced by amphetamine were greatly attenuated by PRN lesions. The results indicate that there exists a PRN-striatal dopamine link in rat brain which mediates the amphetamine-induced increases of locomotion and turnings, as well as decreases of postural freezing.

Amphetamines↗

PubMed1993

[Intracranial arteriovenous malformations in Taiwan].

This paper analyzes the available literature on intracranial arteriovenous malformations (AVM) in Taiwan. The incidence and symptoms of the disease are studied with a view to assisting practitioners in its recognition. The incidence of intracranial AVM in patients who have suffered hemorrhagic stroke in Taiwan is 2.5% to 4.8%, with the male to female ratio being 1.5:1. The peak age at which bleeding from intracranial AVM occurred ranged from 10 to 40 years; bleeding showed no seasonal variation. Sudden headaches, vomiting, and disturbance of consciousness were the commonest presenting symptoms of AVM, similar to the rupture of intracranial aneurysms. However, the possibility of focal neurological deficit among patients with intracranial AVM was higher than in patients with intracranial aneurysms. Risk factors, such as hypertension, diabetes mellitus, heart disease, smoking and alcohol intake showed no close relationship to bleeding in intracranial AVM. Pregnancy is not a risk factor in female patients with intracranial AVM with no history of hemorrhage. Small intracranial AVM are more likely to bleed. Since 1961 the majority of Taiwan's intracranial AVM patients have been treated surgically, while before that date general medicine was the treatment of choice. In recent years, several developments such as operation microscope, microsurgical instruments and microsurgical techniques have enhanced the efficacy of surgical intervention in the treatment of AVM. When the mortality and morbidity rates resulting from the two forms of treatment are compared, surgical treatment shows a better prognosis for the treatment of intracranial AVM.

Adolescent↗

PubMed1993

Neurobehavioral manifestations following closed head injury.

This study was designed to examine neurobehavioral sequelae following closed head injuries. It adapted the Neurobehavioral Rating Scale (NRS) which was designed by Harvey S. Levin in 1987. The scale has been proven to be valid and reliable in previous Western studies and was translated by the authors into Mandarin with the consent of its designer. A total of 335 cases of closed head injury in eight major hospitals in Taipei were studied. The main findings obtained from this preliminary study were: 1) the correlation coefficients between raters ranged from 0.749 to 0.956, manifesting satisfactory reliability; 2) seven factors were obtained through factorial analysis of NRS, explaining 65.5% of the variance; and 3) significant differences in neurobehavioral change were found in patients with various degrees of severity and various types of head injuries. The results demonstrate that NRS is applicable to Chinese patients. Possible modification as well as elaboration of this scale is suggested.

Analysis of Variance↗

PubMed1992

Micromonospora RNA polymerase activity changes during stationary phase.

RNA polymerase was isolated from Micromonospora echinospora and from Streptomyces lividans. In vitro transcription of a DNA fragment containing multiple tandem promoters from Micromonospora followed the pattern of expression observed previously for in vivo studies. RNA polymerase was prepared from cultures of Micromonospora that were harvested during the growing phase and during the stationary phase. Promoters that were utilized in Micromonospora only during the stationary phase were utilized in vitro only when RNA polymerase was purified from a stationary-phase culture, and not when RNA polymerase was purified from growing cells.

DNA-Directed RNA Polymerases↗

PubMed1992

Mutations in the P1 promoter region of Micromonospora echinospora.

We demonstrated previously that the promoters P1a, P1b, and P1c are very closely spaced and are coordinately turned on during stationary phase in Micromonospora echinospora. To determine the nucleotides important for promoter recognition, we characterized mutations that were defective in transcription from the P1b start site, using Streptomyces lividans as the host. Two mutations upstream of the start site resulted in a drastic loss of promoter activity, while two mutations downstream of the start site resulted in a moderate loss of activity. These mutations suggest an unexpected relationship between promoters P1b and P1c. Three of the mutations that caused diminished transcription from promoter P1b simultaneously resulted in an increase in transcription from the P1c promoter initiation site located 15 bp downstream. Despite the proximity and the coordinate regulation of promoters P1b and P1c, they are in competition as transcriptional start sites.

Base Sequence↗

PubMed1992

[Epidemiologic study of head injuries in Taipei City, Taiwan].

This study was designed to examine the descriptive epidemiology of head injuries in an urban population in the Taiwan area, Taipei City, during the period from July 1, 1987 to June 30, 1988. Clinical records reviewed included emergency room (ER) charts, inpatient charts of 19 major hospitals, death registration forms and medical examiners' reports in this city. A formulated definition was used to identify patients with head injuries. A total of 4,692 cases were collected, which included 4,319 hospital inpatients and 373 non-hospital deaths. The average incidence rate for head injury was 180/100,000 per year, 246/100,000 for males and 111/100,000 for females. The highest incidence rate was observed in the elderly group followed by the age group of 20-29 years. Sixty eight percent of the head injuries were caused by traffic accidents, 59.7 percent of which were involved in motorcycle rides. This rate was higher than those in any western reports. Among the 10-39 age group, the head injuries caused by traffic accidents were mainly due to motorcycle accidents. However, most of the children and the elderly who were injured were either pedestrians or bicycle riders. The average mortality rate was 23/100,000 per year, 34/100,000 for males and 12/100,000 for females. Initially the Glasgow Coma Scale was used in assessing the severity of head injuries. Seventy-two percent of the cases were considered mild, and 28 percent moderate to severe in degree, including 609 deaths.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Differential scanning calorimetry of plant cell walls.

High-sensitivity differential scanning calorimetry has been used to study the phase transition of cell wall preparations of the elongating and mature regions of soybean hypocotyls and of celery epidermis and collenchyma strands. A step-like transition believed to be glass transition was observed in walls isolated from the elongating region of soybean hypocotyls at 52.9 degrees C. Addition of 1 mM CaCl2 to the cell wall preparation increased the transition temperature to 60.8 degrees C and greatly reduced the transition magnitude. In walls from the mature region, the transition was small and occurred at a higher temperature (60.1 degrees C). Addition of calcium to the mature region cell wall had little effect on the transition. Based on the known interactions between calcium and pectin, we propose that calcium affects the glass transition by binding to the polygalacturonate backbone of wall pectin, resulting in a more rigid wall with a smaller transition at a higher temperature. The mature region either has more calcium in the wall or has more methyl-esterified pectin, making it less responsive to added calcium.

Journal Article↗

PubMed1991

Expression of Ascorbic Acid Oxidase in Zucchini Squash (Cucurbita pepo L.).

The expression of ascorbic acid oxidase was studied in zucchini squash (Cucurbita pepo L.), one of the most abundant natural sources of the enzyme. In the developing fruit, specific activity of ascorbic acid oxidase was highest between 4 and 6 days after anthesis. Protein and mRNA levels followed the same trend as enzyme activity. Highest growth rate of the fruit occurred before 6 days after anthesis. Within a given fruit, ascorbic acid oxidase activity and mRNA level were highest in the epidermis, and lowest in the central placental region. In leaf tissue, ascorbic acid oxidase activity was higher in young leaves, and very low in old leaves. Within a given leaf, enzyme activity was highest in the fast-growing region (approximately the lower third of the blade), and lowest in the slow-growing region (near leaf apex). High expression of ascorbic acid oxidase at a stage when rapid growth is occurring (in both fruits and leaves), and localization of the enzyme in the fruit epidermis, where cells are under greatest tension during rapid growth in girth, suggest that ascorbic acid oxidase might be involved in reorganization of the cell wall to allow for expansion. Based on the known chemistry of dehydroascorbic acid, the end product of the ascorbic acid oxidase-catalyzed reaction, we have proposed several hypotheses to explain how dehydroascorbic acid might cause cell wall "loosening."

Journal Article↗

PubMed1991

[Trauma score and injury severity score in evaluation of the trauma patients: a preliminary report of 1000 cases].

It is important to evaluate trauma patients with a properly graded severity system in the emergency management of these patients. In this study the Trauma and the Injury Severity Scores based on the evaluation of trauma patients at the emergency services of Mackay Memorial Hospital and Taipei Medical College Hospital, and the mortality rate of these patients is analyzed. There was not a single mortality in patients with a Trauma Score of 15 or 16 and no survival in the patients with Trauma Scores under 11. Eighty-three of 1000 patients (8.3%) had a Trauma Score under 16, and hospitalization was necessary for most of them. All the 22 fatal cases had an Injury Severity Score greater than 24. The mortality rate was 70.6% for the patients with an Injury Severity Score greater than 30. This was the first trial in Taiwan to evaluate patients with the Trauma Score in the hope of aiding medical and paramedical staffs in the selection hospitals to which to transfer patients. All patients having a Trauma Score under 14 should be transferred to well-equipped trauma centers and those with a better score to other hospitals. The Injury Severity Score is nowadays used widely in the world to evaluate the severity and to predict the outcome of the patients. By comparing and utilizing these two grading systems, a more accurate evaluation of the trauma patients can be expected.

Emergency Medical Services↗

PubMed1990

The human lung fibroblast cell line, MRC-5, produces multiple factors involved with megakaryocytopoiesis.

The human lung fibroblast cell line MRC-5 constitutively produces a megakaryocyte potentiator activity, identified in murine bone marrow liquid culture assays for acetylcholinesterase and megakaryocyte colony assays in the presence of low concentrations of IL-3. The production levels of this activity were increased after stimulation with the phorbol ester analog, mezerein, and the calcium ionophore, A23187. Complete purification of a protein having this activity from conditioned media of induced MRC-5 cells was achieved using gel filtration and ion exchange chromatography. The first 14 residues of the purified protein identified by amino-terminal sequencing were identical to the first 14 residues of IL-6. Recombinant human IL-6 was tested and found to promote megakaryocyte growth. IL-1 beta, another component detected in MRC-5 conditioned media, was unable to promote megakaryocyte colony formation but did reduce the concentration of IL-6 necessary to support megakaryocyte colony formation. Immunoprecipitation using rabbit antiserum prepared against IL-6 removed the megakaryocyte growth activity found in MRC-5 conditioned media. Thus, connective tissue cells such as fibroblasts in the bone marrow may co-stimulate thrombocytopoiesis via IL-6 and, possibly, via IL-1 production.

Acetylcholinesterase↗