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R Lim

Publications and source records attributed to R Lim.

At least 73 records · Page 4Linked to original sources
PubMed1994

Ciliary neurotrophic factor (CNTF) enhances the effects of nerve growth factor on PC12 cells.

The rat pheochromocytoma cell line PC12 responds readily to nerve growth factor (NGF) but poorly to ciliary neurotrophic factor (CNTF). However, in a selected line derived from PC12 that normally responded weakly to NGF, CNTF potentiated the effect of NGF with respect to inhibition of proliferation, neurite outgrowth, and choline acetyltransferase (ChAT) induction. ChAT activity was assayed enzymatically, and an increase in the mRNA of ChAT was also detected by means of reverse transcription-polymerase chain reaction (RT-PCR). The PCR product was verified by sequencing and by Southern hybridization using a specific oligonucleotide probe. The presence of CNTF receptor in PC12 cells was confirmed by RT-PCR for its mRNA. The results indicate that PC12 responds to CNTF mainly when used in combination with NGF, and suggest an interaction between the two growth factors.

Adrenal Gland Neoplasms↗
PubMed1994

Suppression of inducible painless myocardial ischemia by conventional medical therapy: effect on short-term outcome and left ventricular systolic function.

To test the hypothesis that abolition of exercise-induced painless myocardial ischemia by anti-ischemic medication improves prognosis in patients with medically treated coronary artery disease, we studied such patients with painless ischemia during exercise radionuclide ventriculography performed after temporary discontinuation of medication. The test was repeated while patients received conventional medical therapy that rendered angina no worse than New York Heart Association class I. The relative risk of adverse cardiac events was reduced by > 5-fold when painless ischemia was abolished by symptom-dictated therapy. Thus, the abolition of exercise-induced painless ischemia by conventional medical therapy carries a better short-term prognosis in medically treated coronary artery disease, suggesting that therapeutic efficacy may need to be assessed by titration against ischemia and not angina. In patients without overt cardiac events, there were no significant differences between baseline and 12-month measurements of ejection fraction at rest, peak exercise, and the change in ejection fraction from rest to exercise. Thus, in those who remain asymptomatic and event-free, painless ischemia that is easily inducible at baseline despite medication does not lead per se to deterioration of left ventricular systolic function at rest or during exercise over 12 months. Such an effect, if evident as early as at 12 months, would favor a strategy of early revascularization over medical treatment in asymptomatic patients who have inducible painless ischemia despite medication.

Adrenergic beta-Antagonists↗
PubMed1994

Exercise testing without interruption of medication for refining the selection of mildly symptomatic patients for prognostic coronary angiography.

OBJECTIVE: To examine how exercise testing on background medical treatment affects the ability of the test to predict prognostically important patterns of coronary anatomy in patients with a high clinical probability of coronary artery disease but who are well controlled on medication. DESIGN: Prospective study. SETTING: Regional cardiothoracic centre and referring district general hospital. PATIENTS: 84 patients with a history of typical angina or definite myocardial infarction and mild symptoms who had been placed on the waiting list for prognostic angiography. INTERVENTION: Maximal exercise electrocardiography and radionuclide ventriculography performed off and on medication, followed by angiography within three months. MAIN OUTCOME MEASURE: Prognostically important coronary artery disease for which early surgery might be recommended purely on prognostic grounds, irrespective of symptoms. RESULTS: Coronary artery disease was present in 71/84 (85%) patients; in 28/84 (33%) patients this was prognostically important. When the result was strongly positive, the predictive accuracy for prognostically important disease was 0.46 off and 0.62 on medication for the exercise electrocardiogram and 0.71 off and 0.82 on medication for exercise radionuclide ventriculography. The likelihood ratio was 1.00 off and 1.36 on medication for exercise electrocardiography and 2.54 off and 10.5 on medication for exercise radionuclide ventriculography. In stepwise logistic regression, the test identified as the strongest predictor of prognostically important disease was exercise radionuclide ventriculography on medication for which the improvement chi 2 was 28 (p < 0.0001). With the regression model, the probability of important disease is 92% if exercise radionuclide ventriculography on medication is at least strongly positive, compared with 16% if the result is normal or just positive. CONCLUSION: In patients likely to have coronary disease, exercise testing should be performed without interruption of medication to optimise its ability to identify those with prognostically important disease, and to help to avoid unnecessary or premature angiography in those who are well controlled on medical treatment.

Adult↗
PubMed1994

The isolation of differentially expressed genes in fibroblast growth factor stimulated BC3H1 cells by subtractive hybridization.

We have developed a subtractive hybridization procedure based on the hybridization of a single-stranded phagemid cDNA library (target) to biotinylated RNA (driver). We have applied this method to fibroblast growth factor (FGF) induced-uninduced mouse brain tumor-derived muscle-like cell. BC3Hl cDNA libraries. After hybridization to a C(o)t value of 1000, cDNAs common to the target and driver populations were subtracted up to 231-fold, whereas several highly induced genes were enriched from 2-15-fold. Interestingly, moderately induced genes (e.g., the 12-fold-induced nur/77 gene) were subtracted even at a low C(o)t value of 50. Therefore, at every C(o)t tested, subtractive hybridization tended to equalize the uninduced and moderately induced common sequences within target populations regardless of the abundance of the gene species. These observations suggest that subtractive hybridization should only be used for identifying target genes that are either uniquely expressed or highly induced.

Animals↗
PubMed1994

Balinese birth.

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Female↗
PubMed1993

Long-term effect of inducible silent ischaemia on left ventricular systolic function.

Silent myocardial ischaemia is readily detected by exercise radionuclide ventriculography in patients with coronary artery disease. In those who remain asymptomatic and event-free, it is not known whether silent ischaemia which is inducible despite anti-ischaemic medication exerts an insidious detrimental effect on left ventricular function. To study this, 34 medically treated patients (mean age 57; 26 men) underwent prospective measurement of left ventricular ejection fraction (LVEF) during rest and exercise radionuclide ventriculography without interruption of anti-ischaemic medication at baseline and 12 months later. There was no significant mean (standard deviation, 95% confidence interval) deterioration from baseline to 12 months in LVEF at rest (50% v 49%, SD 5; 95% CI = -3 to +1), peak exercise (44% v 45%, SD 8; 95% CI = -1 to +4) and the change in LVEF from rest to exercise (-6% v -4%, SD 7; 95% CI = -1 to +5). Thus, in coronary artery disease patients who remain asymptomatic and event-free on medical therapy, silent myocardial ischaemia which is readily inducible at baseline despite medication does not lead per se to deterioration of left ventricular systolic function at rest or exercise over 12 months.

Adult↗
PubMed1993

Serum cholesterol concentration before and after streptokinase in acute myocardial infarction.

OBJECTIVE: To determine if serum cholesterol concentration should be measured before or after streptokinase therapy within the first 24 h of myocardial infarction. DESIGN: Prospective study of patients receiving streptokinase therapy for acute myocardial infarction (AMI). SETTING: Coronary care unit of a district general hospital. SUBJECTS: Thirty-one patients (26 men aged 38-74 years, mean 60 years) admitted with a definite diagnosis of myocardial infarction. INTERVENTION: Streptokinase therapy given intravenously at a mean of 5 h (range 1.5-15 h) after the onset of chest pain. MAIN OUTCOME MEASURES: Serum cholesterol concentration just prior to, and 11.5 h (range 4-20.5 h) after streptokinase administration. RESULTS: There was a significant mean fall of 0.4 mmol l-1 (P = 0.002, 95% CI = 0.2-0.6) in serum cholesterol concentration from a pre-streptokinase concentration of 7.0 (range 5.3-9.9) to a post-streptokinase concentration of 6.6 (range 4.9-9.9). In the patients who showed a fall in cholesterol concentration, the magnitude of fall correlated with the baseline cholesterol concentration (r = 0.66, P < 0.01) but not with peak cardiac enzyme activities (r = 0.05, P > 0.2 for aspartate aminotransferase; r = 0.10, P > 0.2 for lactate dehydrogenase), time from onset of chest pain to post-streptokinase measurement (r = 0.27, P > 0.2) or time from streptokinase administration to post-streptokinase measurement (r = 0.01, P > 0.2). CONCLUSION: Serum cholesterol concentration may be underestimated when measured after streptokinase therapy, particularly when the true basal value is high. Further management of this risk factor may be based more accurately on its measurement before than after streptokinase therapy within the first 24 h of AMI.

Adult↗
PubMed1993

Expression of glia maturation factor beta mRNA and protein in rat organs and cells.

Rat glia maturation factor beta (GMF-beta) cDNA was obtained by reverse transcription of rat brain mRNA followed by polymerase chain reaction amplification, using primers from the human sequence. The deduced amino acid sequence of rat GMF-beta differed from the human counterpart in only three places: His27 in place of Asn, Val51 in place of Ile, and Leu93 in place of Val. The high degree of evolutionary conservation suggests that GMF-beta plays an essential role in animal cell physiology. The expression of GMF-beta mRNA in the rat was studied by the northern blot technique, using a rat cRNA probe corresponding to the entire coding region. GMF-beta mRNA was predominantly expressed in the brain and spinal cord, although trace levels were found in other organs, including testis and ovary. In the brain GMF-beta mRNA was detectable at as early as embryonic day 10, and persisted through as late as postnatal month 14, with minor variations in between. On the other hand, GMF-beta protein exhibited more obvious developmental changes, with its level increasing slowly prenatally and plateauing at 1 week after birth. GMF-beta mRNA and protein were also observed in several cultured cells. Some cells of neural origin contained higher levels of GMF-beta protein compared with cells derived from other sources. Through demonstration of mRNA and confirmation by immunoblotting, we conclude that GMF-beta is synthesized by rat organs and that GMF-beta is predominantly a brain protein.

Amino Acid Sequence↗
PubMed1993

Novel approach to the interpretation of long-term "deterioration" in ejection fraction in individual patients with coronary artery disease.

OBJECTIVE: The long-term predictability of left ventricular ejection fraction (LVEF) measurements was evaluated with particular emphasis on the assessment of deterioration in individual patients whose coronary artery disease was initially treated medically. DESIGN: Prospective pilot study. SETTING: Regional cardiac centre. PATIENTS: 60 minimally symptomatic patients with coronary artery disease who, after arteriography, were initially treated medically. INTERVENTION: Measurement of LVEF by first pass exercise radionuclide ventriculography at baseline and six months later without interruption of usual anti-ischaemic medication. Baseline and six-month studies were analysed independently of each other. MAIN OUTCOME MEASURE: Based on 51 patients who remained event free, 95% prediction intervals were derived for prognostic LVEF indices to suggest the minimum change from baseline that might be considered clinically important in the individual patient, alerting clinicians to the need for closer review. RESULTS: At six-month ventriculography, 22 patients showed apparent deterioration in exercise LVEF or the change in LVEF with exercise (delta LVEF). Only two patients had six-month values below the lower limit of 95% prediction intervals, compared with 15 when 95% group confidence intervals (z = 3.33, p < 0.001) were used. When delta LVEF = 0 at baseline, the lower limit of 95% prediction intervals allowed for an exercise induced fall at six months of < or = 13%. For a baseline exercise LVEF of 50% (just normal), the lower limit of 95% prediction intervals was 38%--that is, the exercise LVEF could be measured as low as 38% > or = six months later without necessarily indicating or missing true deterioration. CONCLUSION: In the follow up of minimally symptomatic patients with coronary artery disease, serial long-term changes, in particular "deterioration," in prognostic LVEF indices may be interpreted more meaningfully with reference to 95% prediction intervals.

Adult↗
PubMed1993

A window to Bali.

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Cesarean Section↗
PubMed1992

Polyclonal antibody localizes glia maturation factor beta-like immunoreactivity in neurons and glia.

A rabbit polyclonal antibody (91-01) was raised against recombinant human glia maturation factor beta (r-hGMF-beta). The antibody did not cross-react with a number of other growth factors on ELISA test. When compared with the monoclonal antibody G2-09 previously obtained, 91-01 immunoblotted the same protein band in rat brain extract. However, unlike G2-09 which immunostained only astrocytes and Bergmann glia, 91-01 stained neurons as well. Many but not all neurons in the central and peripheral nervous system were positive for GMF-beta. The larger cell population stained by the polyclonal antibody was most likely due to its increased sensitivity, although other explanations are possible. The presence of GMF-beta-like immunoreactivity in both neurons and glia raises the possibility of a wider range of cell-cell interaction than was previously considered.

Animals↗
PubMed1992

Effect on prognosis of abolition of exercise-induced painless myocardial ischemia by medical therapy.

During exercise radionuclide ventriculography, many patients with coronary artery disease exhibit painless myocardial ischemia defined as an abnormal left ventricular ejection fraction response without accompanying angina. To see if complete suppression of such exercise-induced painless ischemia by anti-ischemic medication implies a better prognosis in medically treated coronary artery disease, 34 patients underwent repeat testing at 4 weeks receiving regular conventional therapy that rendered angina no worse than class I. With such therapy, painless ischemia was abolished in 12 patients (group I) and persisted in 22 (65%, group II). Both groups were similar in age, number of diseased vessels, proportion with previous myocardial infarction, exercise ejection fraction, and degree of exercise-induced painless ischemia at baseline. At 9 months, adverse events had occurred in 11 patients (2 patients with myocardial infarction, 4 with unstable angina, 2 with angioplasty and 3 with bypass surgery). Only 1 of 12 patients (8%) in group I had experienced events compared with 10 of 22 (45%) in group II (chi-square, 5.4; p less than 0.025; 95% confidence interval, 12 to 61%). Thus, the relative risk of adverse events in patients whose painless ischemia was abolished was only 18% of that in patients in whom it was persistent. These results suggest that (1) the abolition of exercise-induced painless ischemia by conventional symptom-dictated medical therapy confers a better short-term prognosis in medically treated coronary artery disease, and (2) therapeutic efficacy may need to be assessed by titration against ischemia and not against angina.

Adult↗
PubMed1992

High-risk coronary angioplasty with elective intra-aortic balloon pump support.

Percutaneous transluminal coronary angioplasty was attempted with elective percutaneous intra-aortic balloon pump support in 21 patients (mean age 60 years, range 40-82; 18 males) with unstable angina (n = 2), multivessel coronary disease requiring multivessel angioplasty (n = 2), severe left ventricular dysfunction (ejection fraction 10-30%; n = 16) or ventricular fibrillation at diagnostic angiography (n = 1). Fourteen patients had 3-vessel disease (1 with vein grafts also diseased), 6 had 2-vessel disease and 1 had isolated left anterior descending disease. Twenty-five procedures were performed (one in 18 patients, two in 2 patients and three in one patient) on 42 lesions in 34 vessels/grafts. There was no angioplasty-related death. Successful dilatation was achieved in 38/42 lesions (90%) in 21/25 procedures (84%) without major complication. Three procedures were complicated: one by major coronary dissection without sequelae, one by haemodynamic deterioration due to distal occlusion and one by an unstable residual stenosis in the attempted vessel necessitating urgent bypass surgery. The only complication related to the intra-aortic balloon pump was local haematoma in 2 patients. In conclusion, elective intra-aortic balloon pump support may be safely used to stabilise high-risk patients undergoing coronary angioplasty, leading to a satisfactory primary success rate.

Adult↗
PubMed1992

Benign mesodermal tumors producing nasal deformity.

Tumors of neurogenic (ectodermal) origin are well-described causes of nasal deformity. We present a patient with a benign mesodermal tumor (unclassified spindle cell) producing nasal deformity. A retrospective review of the two senior authors' records provided an additional three patients with nonvascular benign mesodermal nasal masses (fibroma and leiomyoma). Benign mesodermal masses can occur in the midline of the nose and need to be differentiated from dermoids and gliomas. Misdiagnosis is the rule. Excisional biopsy is required for definitive diagnosis. In addition, excisional biopsy is curative and can help to minimize the subsequent nasal deformity if performed early in the disease process. Immunohistochemical and electron microscopy may be required for comprehensive diagnosis and treatment.

Adult↗
PubMed1992

Interaction of acidic fibroblast growth factor and transforming growth factor-beta in normal and transformed glia in vitro.

The mitogenic and morphological effects of acidic fibroblast growth factor (aFGF) and transforming growth factor-beta (TGF-beta) were assessed on cultured fetal rat astrocytes and C6 rat glioma cells in the presence and absence of serum. Astrocytes incubated with aFGF exhibited an increase in mitotic activity and characteristic morphological changes involving extensive process formation and rounding of cell bodies. Astrocytes incubated with TGF-beta underwent a slight decrease in mitotic activity and remained morphologically unchanged. Cells exposed to a combination of aFGF and TGF-beta demonstrated an attenuation of both the mitogenic and morphological changes observed in the presence of aFGF alone. The C6 glioma cells cultured in the presence of aFGF underwent a characteristic morphological change from a rounded piling cell mass to a more spindle-shaped bipolar cell layer, accompanied by an increase in mitotic activity. In contrast to the astrocyte cultures, increased growth and similar morphological effects were produced by TGF-beta. The combination of aFGF and TGF-beta did not result in attenuation of the mitogenic and morphological changes (as seen in astrocytic cells). These results suggest that, in normal fetal rat astrocytes, TGF-beta is capable of attenuating the mitogenic and morphological changes induced by aFGF in vitro. In the transformed C6 glioma cell line, aFGF and TGF-beta elicit similar mitogenic and morphological changes, without evidence of an antagonistic interaction as seen in normal astrocytes.

Animals↗