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Biomedical subjects

S C Lim

Publications and source records attributed to S C Lim.

At least 55 records · Page 3Linked to original sources
PubMed1998

The interactive effect of Ras, HER2, P53 and Bcl-2 expression in predicting the survival of non-small cell lung cancer patients.

In patients with non-small cell lung cancer (NSCLC), tumor expression of P21-Ras, HER2, P53, and Bcl-2 has been reported as independent predictors of prognosis. However, the prognostic information carried by these proteins has usually been determined separately, and their potential interaction has not been taken into account. We conducted immunostaining for P21-Ras, HER2, P53 and Bcl-2 on 238 cases of NSCLC in a Korean population with 203 squamous cell carcinomas, and 35 adenocarcinomas. P21-Ras, HER2, P53 or Bcl-2 was expressed at high levels in 54.6, 42.0, 18.1 and 71.8% of the NSCLC studied, respectively. A total of 59 tumors (24.8%) expressed only one protein, while 70 (29.4%) expressed two, 59 (24.8) expressed three, and 17 tumors (7.1%) expressed all four proteins. Univariate analysis testing the association of marker expression with survival found Bcl-2 expression to be significantly associated with a poor prognosis, as well as the co-expression of Bcl-2 + HER2, Bcl-2 + HER2 + P53, and Bcl-2 + HER2 + P53 + P21-ras with an increasing hazard ratio. By multivariate analysis controlling for age, tumor stage and tumor type, only the combination of Bcl-2 + HER2 expression was an independent marker of poor prognosis (hazard ratio = 1.91, P = 0.003). Thus, a prospective analysis of the co-expression of Bcl-2 + HER2 in NSCLC patients may identify patients with a poor prognosis who may benefit from more aggressive therapy.

Adenocarcinoma↗
PubMed1998

Giant hidradenocarcinoma: a report of malignant transformation from nodular hidradenoma.

A giant hidradenocarcinoma presented by a 75-year-old female is reported. The patient had a malignant transformation within a nodular hidradenoma involving the right postauricular area, which was treated by mass removal and a right radical neck dissection with a free-flap covering. Malignant hidradenocarcinoma is the least common adnexal tumor of uncertain origin. They are usually malignant from their inception, but some develop from a benign counterpart. To the authors' knowledge, only three cases have been reported previously. Two histologically distinct components were seen in this tumor: (i) typical nodular hidradenoma, which constituted a small part of the tumor; and (ii) carcinoma with areas of transition. The secretory cells of hidradenocarcinoma showed decapitation secretion on light and electron microscopic observations, which is evidence of apocrine differentiation. Histologically, this case was concluded as a hidradenocarcinoma arising from a long-standing nodular hidradenoma. A literature review is presented and the histological, immunohistochemical and ultrastructural features are described.

Adenoma, Sweat Gland↗
PubMed1998

A case of small cell carcinoma arising in a mature cystic teratoma of the ovary.

Malignant transformation of ovarian mature cystic teratomas is reported to occur in about 1% of cases. The most common malignant evolution is that of squamous cell carcinoma and one of the least common is that of small cell carcinoma. We report a case of distant metastasis from a small cell carcinoma arising in a mature cystic teratoma. A 28-year-old nulliparous female presented with signs of supraclavicular lymph node metastasis. This is the first known case report of lymph node metastasis as an initial sign of cancer developing in a pre-existing mature cystic teratoma. Histologically, the tumor cells had microscopic features similar to those of pulmonary small cell carcinoma. This report gives a literature review, and the histological, immunohistochemical, flow cytometric and ultrastructural features are described.

Adult↗
PubMed1998

Malignant mixed Müllerian tumor (homologous type) of the adnexa with neuroendocrine differentiation: a case report.

Malignant mixed müllerian tumors (MMMT) are unusual neoplasms occurring mostly in the uterus. In the ovary, they are very rare and represent fewer than 1% of all ovarian malignancies; in the salpinx, they are even rarer than those of the ovary. We report a carcinosarcoma of the left adnexa having features of neuroendocrine differentiation in a 69-year-old female. The tumor contained both adenocarcinoma and squamous cell carcinoma having dear cell change admixed with an undifferentiated malignant mesenchymal component. The sarcoma components consisted of spindle cells, small-round cells and bizarre giant cells mimicking rhabdomyoblast. Almost all of the carcinomatous glandular components and some foci of the squamous cell and undifferentiated carcinomatous components were focal positive for S-100 protein, chromogranin, neuron specific enolase, synaptophysin and Leu-7. Electron microscopy revealed membrane-bound neurosecretory granules in the cytoplasm of some glandular epithelial cells. Histologically, the tumor involved the left adnexa, abdominal peritoneum, surface of the bladder dome, omentum and left external iliac lymph node (stage IIIc).

Adnexa Uteri↗
PubMed1998

A case report of a patient with bronchial carcinoid tumour and late presentation of Cushing's syndrome.

Bronchial carcinoid tumour with ectopic adrenocorticotrophin (ACTH) production is an uncommon cause of Cushing's syndrome. In most instances, the patient presents with clinical hyperglucocorticolism and a search for its underlying pathology leads to the discovery of an inconspicuous bronchial carcinoid tumour, if at all. Often the tumour is not immediately detectable. We report a patient who presented in the reverse order--she initially had a large asymptomatic bronchial carcinoid tumour that subsequently manifested as clinical Cushing's syndrome after remaining quiescent for four years.

Adrenocorticotropic Hormone↗
PubMed1997

Tissue response to titanium plates: a transmitted electron microscopic study.

PURPOSE: This study investigated the tissue response associated with titanium plates. MATERIALS AND METHODS: Titanium miniplates were used to stabilize fractured bones and a bone graft in 14 patients. At the time of plate removal, the osteosynthesis sites were carefully examined macroscopically. After the removal of the plates, biopsies of the 14 soft tissues and two bony sites surrounding the plates were performed for light microscopic and transmitted electron microscopic examination. RESULTS: Macroscopically, visible pigmentation was found in the soft tissue in 14% of the patients, but none in the bone. With light microscopy, pigmentation was found in the soft tissue of 10 of 14 sites and in one of two bony sites. Transmitted electron microscopy showed suspected titanium particles in the connective tissue of all specimens. The small particles were located between the collagen fibers. In some specimens, small particles were noted within the fibroblasts and macrophages. There were degenerative changes around the minute particles in the bone matrix. CONCLUSION: Local macroscopic or microscopic tissue destruction was observed in hard and soft tissue near the titanium miniplates. If the plates remain for a long time, there is a possibility that they may cause further tissue damage. These findings suggest that the titanium miniplates should be removed routinely after bone healing.

Adolescent↗
PubMed1997

Combining ADA, protein and IFN-gamma best allows discrimination between tuberculous and malignant pleural effusion.

BACKGROUND: The purpose of this study is to assess the usefulness of various enzymes, cytokines and biochemical studies of pleural fluid for the differential diagnosis of tuberculosis from malignant pleural effusions, and to clarify the role of combining diagnostic tests. METHODS: The study group included 39 cases with tuberculous effusions and 31 cases with malignant effusions, whose diagnoses were confirmed by pleural biopsy, cytology or microbiological methods. We compared pleural fluid levels of ADA, TNF-alpha, IFN-gamma, IL-2, IL-6, IL-8, pH, protein, glucose, cholesterol, triglyceride, amylase and lactic dehydrogenase between tuberculous and malignant effusions. Using stepwise logistic regression analysis, we evaluated the benefit of combining various parameters. Receiver operating characteristic(ROC) curves of ADA, cytokines and equations generated from regression analyses were plotted and compared with the area under curve(AUC). Cut-off values showing the best diagnostic accuracy were selected and compared. RESULTS: Compared to malignant effusion, tuberculous effusion showed significantly higher levels of ADA, IFN-gamma, TNF-alpha and IL-2. There was a good correlation between IFN-gamma and TNF-alpha. By stepwise logistic regression analysis, IFN-gamma, protein and ADA were independent variables predicting tuberculous from malignant effusions. The diagnostic accuracy and AUC of regression equation was greater than any other single parameters. CONCLUSION: For the differential diagnosis of tuberculosis and malignant pleural effusions, combining ADA, protein and IFN-gamma best allows discrimination.

Adenosine Deaminase↗
PubMed1997

Thyroid stimulating hormone receptor antibody levels in Singaporean patients with autoimmune thyroid disease.

Stimulating thyrotrophin receptor antibodies (TRAbs) have been identified as the antibodies responsible for the pathogenesis of Graves' disease (GD) while blocking TRAbs have been implicated as the cause of hypothyroidism in some patients with chronic lymphocytic thyroiditis (CLT). TRAb positivity in patients with other thyroid disorders such as silent thyroiditis, toxic multinodular goitre and subacute thyroiditis has been reported but the role of TRAb in these disorders is unclear. A study was carried out to determine the prevalence of TRAb positivity in Singaporean patients with a spectrum of thyroid diseases. TRAb levels were measured in 181 patients with GD, 54 patients with CLT (37 goitrous and 17 agoitrous), 16 patients with thyroid nodules, 11 patients with subacute thyroiditis, 1 patient with hyperthyroidism due to a human chorionic gonadotrophin (HCG)-secreting tumour, 2 patients with thyroid stimulating hormone-secreting tumours and 2 patients with amiodarone-induced dysthyroidism. Using a cut-off of 10.0 U/L, TRAb levels were found to be positive in 79.0% of GD patients, 9.2% of CLT patients (euthyroid and hypothyroid) and no patients with other thyroid disorders. TRAb was a more sensitive marker of GD than anti-thyroglobulin antibodies (53.2%) but not anti-microsomal (78.3%) antibodies. TRAb levels > 10.0 U/L appear to be highly specific for autoimmune thyroid disease.

Biomarkers↗
PubMed1997

Aldosterone to renin ratios in the evaluation of primary aldosteronism.

Primary aldosteronism, though an uncommon cause of hypertension, causes significant morbidity, making it important to diagnose and treat this condition. Its evaluation requires complex and time consuming investigative procedures in order to confirm the diagnosis and to differentiate between the subtypes of aldosterone producing adenoma and idiopathic hyperaldosteronism. Often, the values of renin and aldosterone are equivocal, and the diagnosis of primary aldosteronism is in doubt. In this study, we examine the use of aldosterone to renin ratios in confirming the diagnosis of primary aldosteronism when the usual criteria of suppressed renin and elevated aldosterone are not met. We have found that an aldosterone to renin ratio of 50 has a 100% specificity and 92% sensitivity for detecting primary aldosteronism. Also, an aldosterone to renin ratio of > 2000 is suggestive of an aldosterone producing adenoma.

Adrenocortical Adenoma↗
PubMed1996

A comparison of serum CYFRA 21-1 and SCC Ag in the diagnosis of squamous cell lung carcinoma.

To evaluate the usefulness of CYFRA 21-1 and SCC Ag in the diagnosis of squamous cell carcinoma (SQC) of the lung, we tested sera from 124 patients with lung cancers (squamous cell ca 72, adenoca 22, large cell ca 4, small cell ca 18 and undetermined 8) and 78 patients with inflammatory lung diseases (bronchitis 24, bronchiectasis 29, tuberculosis 19 and others 6) using immunoradiometric assay kit for cytokeratin fragment 19 (CYFRA 21-1) and radioimmunoassay kit for SCC Ag. The serum CYFRA 21-1 and SCC Ag were significantly higher in lung cancer patients compared with control subjects. However, the significant difference was restricted only to SQC. In patients with SQC, CYFRA 21-1 and SCC Ag showed significantly higher levels according to the advanced anatomic stages (stage I-IIIa vs. stage IIIb, IV, p < 0.05). There was a good correlation between CYFRA 21-1 and SCC Ag (r = 0.41, p < 0.001). Receiver operating characteristic (ROC) curves were generated from results of both tumor markers and areas under the curves (AUC) were calculated. AUC of CYFRA 21-1 (0.93) were significantly larger than that of SCC Ag (0.77) for the diagnosis of SQC (p < 0.05). Therefore, we conclude that CYFRA 21-1 is superior to SCC Ag in the diagnosis of squamous cell carcinoma of the lung.

Aged↗
PubMed1996

Acute lung injury after phosgene inhalation.

Phosgene (COCl2) is a colorless oxidant gas which is heavier than air and the lethal exposure dose (LC50) in humans is 500 ppm/min. This gas was originally manufactured as an agent for chemical warfare during World War I and there had been a great deal of studies on phosgene poisoning during the early years of industrial use. It is still widely used in the synthesis of chemicals and plastics. In the modern era, however, phosgene poisoning is relatively uncommon except in accidental exposures. In Korea, there has been no report about lung injury from phosgene inhalation. We present a clinical experience with six patients accidentally exposed to phosgene.

Accidents, Occupational↗
PubMed1996

Patient outcome and intensive care resource allocation using APACHE II.

A prospective study of seventy consecutive admissions to the Medical Intensive Care Unit (MICU) of a local hospital over a five-month period was conducted with the aim of developing objective criteria for critical care resource allocation. Patients gaining admission were subjected to APACHE II scoring and their progress followed till they recovered from their illness or perished. The mean APACHE II score of patients who recovered from their illness or perished were 12.96 and 28.52 respectively (p < 0.001). 91.5% of all patients who recovered had an APACHE II score of below 21 whereas 82.6% of those who died had an APACHE II score of more than 23. Males generally had poorer outcome than females [47% mortality vs 8% (p < 0.001)] although their mean ages were comparable [47.6 years vs 46.6 years respectively (p = 0.85)]. The mean APACHE II scores of male and female patients were significantly different [male = 20.6 vs female = 13.6 (p < 0.005)] and this partly accounted for the poorer outcome of males. The APACHE II score has considerable predictive value on the final outcome of patients admitted to the MICU. When ICU beds are short, the allocation of such beds may be made with consideration of the APACHE II Score which identifies the patient who is most likely to benefit from ICU care.

APACHE↗
PubMed1996

Abnormal thyroid and adrenocortical function test results in intensive care patients.

A prospective, cohort study of 75 consecutive patients requiring management in the medical intensive care unit (MICU) of the Singapore General Hospital was carried out over a five-month period to determine thyroid and adrenocortical profiles and evaluate their use in predicting patient outcome. Up to 88% of patients had at least one abnormal thyroid function and 77% had abnormal adrenocortical function test results. There were significantly lower triiodothyronine, thyroxine and free thyroxine, but not thyrotropin levels, and higher cortisol levels in non-survivors compared to survivors (all P < 0.01). Of the endocrine parameters, triiodothyronine and cortisol concentrations were independent predictors of outcome. The overall predictive accuracy of combining these two variables on admission into the MICU was 74%. The APACHE II (acute physiology and chronic health evaluation II) score alone predicted outcome with 71% accuracy, and in combination with triiodothyronine and cortisol levels improved accuracy to 84%. The use of dopamine alone predicted outcome with 74% accuracy, and in combination with triiodothyronine and cortisol levels, improved accuracy to 84%. Measurements of total triiodothyronine and cortisol concentrations on admission to the MICU, and consideration of the use of dopamine improve on the APACHE II score in outcome prediction.

APACHE↗
PubMed1995

Cholinergic regulation of amylase gene expression in the rat parotid gland. Inhibition by two distinct post-transcriptional mechanisms.

Stimulation of the beta-adrenergic or cholinergic muscarinic receptors are the principal mechanisms by which parotid salivary secretion is regulated in vivo. In this study we have examined the effects of cholinergic stimulation on amylase gene expression in dispersed rat parotid cells. [3H]Leucine incorporation into amylase and total protein was inhibited by carbamylcholine. Within 5 min of its addition, 10 microM carbamylcholine induced a 50-60% reduction in the rate of amylase synthesis which was sustained for more than 2 h. Blockade of the muscarinic receptor with atropine 8 min after addition of 10 microM carbamylcholine reversed the carbamylcholine-induced inhibition of amylase synthesis. When cells were exposed to carbamylcholine for 2 h before addition of atropine, there was only a slight reversal of inhibition. Carbamylcholine had no significant effect on the rate of total RNA synthesis but caused a progressive loss of amylase mRNA. After 2 h, amylase mRNA in cells treated with 10 microM carbamylcholine was 46% of control levels. Actinomycin D (5 micrograms/ml) lowered amylase mRNA by 8%; cycloheximide and phorbol 12-myristate 13-acetate had no effect. Isoprenaline (isoproterenol; at a concentration of 10 microM), which is an inducer of amylase gene transcription, elevated the amylase mRNA content by 30% after 2h. The calcium ionophore A23187 mimicked the effect of carbamylcholine by inhibiting [3H]leucine incorporation into amylase and lowering amylase mRNA content. The results suggest that acute stimulation of the muscarinic cholinergic receptor inhibits amylase biosynthesis in parotid cells not only by rapid attenuation of translation but also by causing a gradual loss of amylase mRNA, apparently by a Ca(2+)-dependent destabilization of the mRNA.

Amylases↗
PubMed1994

Long-term effects of pentobarbital anesthesia on the atrial natriuretic peptide system in rats.

A long-term effect of pentobarbital treatment on the storage and release of atrial natriuretic peptide (ANP) was investigated in rats. The experimental group was treated with pentobarbital (50 mg/kg, ip), and the control group was injected with the vehicle only. They were used one week after the treatment. Male and female rats were used separately to see if there exists a sex difference in the response to pentobarbital. In male rats, the plasma ANP measured in a conscious state was significantly higher in the experimental group than in the control. The ANP content as well as the number of specific granules in the atrial tissue was significantly lower in the experimental group. In response to extracellular volume expansion (VE), amounting up to 5% of the body weight over 30 min, while the plasma ANP increased in the control, it did not significantly change in the experimental group. Urinary responses to the exogenous infusion of ANP did not differ in magnitude between the two groups. In female rats, neither the plasma level nor the atrial content of ANP (or the atrial granularity) was different between the experimental and control groups. Nor did the increase of plasma ANP in response to VE differ in magnitude between the two groups in female rats. These results indicate that pentobarbital may have a long-term effect on the storage and release of ANP.

Analysis of Variance↗