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Biomedical subjects

J J Hwang

Publications and source records attributed to J J Hwang.

At least 73 records · Page 4Linked to original sources
PubMed1998

HLA class II allele associations in Korean patients with pemphigus.

BACKGROUND: Studies at the population level have demonstrated associations between pemphigus (pemphigus vulgaris, PV, and pemphigus foliaceus, PF) and particular HLA haplotypes, which suggests that there may be a genetic predisposition for the disease. OBJECTIVE/METHODS: The aim of the present study was to examine the distribution/frequency pattern of HLA class II alleles (DRB1, DQA1 and DQB1) from a group of 30 Korean patients with pemphigus (15 PV and 15 PF) by PCR amplification with sequence-specific primers. RESULTS: In PV, the frequency of DRB1*01 allele was found to be significantly high (pc = 0.0014); in PF, DRB1*01, DQA1*0302 and DQB1*0603 alleles showed positive associations with statistical significances (pc = 0.0002, 0.0007 and 0.0067, respectively), when compared with those found in Korean controls. CONCLUSIONS: In this small-sample study, findings of allelic frequencies among Korean patients with pemphigus are somewhat different from those found in other populations.

Alleles↗
PubMed1998

A retrospective hospital-based study of coronary risk factors in Taiwan. Analysis of patients with established diagnoses.

In Taiwan over the past decades there has been enormous economic growth and rapid westernization of people's life style, as well as a concomitant rise in coronary heart disease (CHD) mortality and morbidity. Studying the effects of such a degree of socioeconomic development on the coronary risk factors of the Chinese population, an ethnic group long regarded as having a low incidence of CHD, may provide some insight into the etiology of coronary atherosclerosis. Coronary risk factors among 1,449 patients (759 with CHD) were retrospectively studied. Diagnosis was established by angiography or a definite history of myocardial infarction in approximately 60% of the patients, and for the remainder, at least by noninvasive testing. The frequencies of dyslipidemia and nonlipid risk factors in patients with and without CHD were determined and compared. The lipid levels of subjects with or without CHD were close to or approaching those reported from the United States. Socioeconomic development and changes in dietary patterns seem influential in this regard. Among risk factors, high-density lipoprotein cholesterol (HDL-C), smoking, diabetes mellitus, hypertension and family history in males and, in females, total cholesterol, HDL-C, diabetes mellitus and hypertension, were significantly and independently correlated with CHD. These risk factors are similar to those found in the West; however, there is an important association of serum HDL-C concentrations with CHD, irrespective of gender. This issue requires further study in Chinese populations in other Asian countries.

Adult↗
PubMed1998

Clinical characteristics and coronary risk factors of patients with low concentrations of serum low-density lipoprotein cholesterol and total cholesterol.

We investigated the clinical characteristics and coronary risk factors of Chinese patients with suspected coronary artery disease (CAD) having low serum concentrations of both low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). Of 1,450 patients with suspected CAD (age range, 30-92 years; 948 men and 502 women), 760 had established CAD. The patients were divided into three groups according to lipid profile patterns. Group 1 patients (n = 138) had low LDL-C concentrations (< 100 mg/dL) and low TC concentrations (< 160 mg/dL). They were characterized by lower triglyceride concentrations, lower frequencies of high TC/high-density lipoprotein cholesterol (HDL-C) ratios (> 5) and LDL-C/HDL-C ratios (> 5), and lower frequencies of a family history of CAD and obesity. Group 3 patients (n = 610) had LDL-C concentrations of 130 mg/dL or above and TC concentrations of 200 mg/dL or above, much higher than in group 1. The prevalence of CAD was 41.3% (57/138) in group 1. 46.7% (328/702) in group 2, and 61.5% (375/610) in group 3. Groups with higher TC and LDL-C concentrations had a higher CAD prevalence. Coronary risk factors of group 1 patients appeared to be low HDL-C concentration, high TC/HDL-C ratio, advanced age, cigarette smoking, hypertension, and diabetes mellitus. Among these risk factors, HDL-C and hypertension were independent predictors of CAD. Unlike in the other two groups, hypertension was the only independent nonlipid risk factor. We conclude that in therapy or prevention of CAD, the goals should be to reduce LDL-C concentration to below 100 mg/dL and the TC concentration to below 160 mg/dL. However, other risk factors should also be considered.

Adult↗
PubMed1997

Insulin activates Ras in the PC12 cell line.

To address whether Ras can be activated by insulin in the PC12 cell line, proteins interacting with insulin receptor and IRS-1 molecules and their tyrosine phosphorylation were analyzed by immunoblotting following immunoprecipitation with antibodies. Tyrosine phosphorylation of the insulin receptor and IRS-1 was increased by insulin. Grb2 and Ras-GAP appeared in the immunoprecipitates by anti-insulin receptor and anti-IRS-1 from insulin-treated cells. In addition, PI 3-kinase was activated by insulin treatment in this cell line and Grb2, Ras-GAP, and MAP kinase were coprecipitated with Ras from both insulin-treated and NGF-treated cells. Analysis of MAP kinases from insulin-treated cells revealed that insulin, like NGF, increased tyrosine phosphorylation. However, activation of the MAP kinase by NGF lasted longer than activation by insulin. These results indicate that Ras can be activated by insulin in the PC12 cell line and that Ras activation is neither an accurate nor a plausible method of discriminating signals between proliferation and differentiation.

Animals↗
PubMed1997

Attenuation of cardiovascular reactions of vocalized and non-vocalized defence areas of periaqueductal grey following lesions in dorsomedial or ventrolateral medulla of cats.

In the pretentorial periaqueductal grey (PAG), the region producing pressor responses, vocalization and other somatic and visceral signs (VPR) of the defence reaction and another region producing pressor responses (PR) were localized by electrical stimulation in adult cats, anesthetized with intraperitoneal chloralose (40 mg/kg) and urethane (400 mg/kg). The pressor responses included increases of systemic arterial pressure (SAP) and heart rate, increases of blood flow in the common carotid and femoral arteries and a decrease of blood flow in the superior mesenteric artery. The VPR was found in a relatively restricted region of the dorsolateral PAG, while PR was found scattered within the dorsal and ventral portions of the lateral PAG. The increase of SAP and the changes of blood flow in the sampled arteries were slightly greater during VPR than PR stimulation. Mild vocalization with a slight increase of SAP but marked increases of carotid and femoral blood flow (vasodilation) could be induced by microinjection of N-methyl D-aspartate (0.2 M, 200 nl) into the VPR and the blood flow increase, particularly that of the femoral artery, was greatly attenuated by atropine (1 mg/kg, i.v.). In order to ascertain the contribution of the medullary pressor areas to the VPR- and PR-induced responses, extensive lesions were made in the dorsomedial (DM) or vetrolateral medulla (VLM) by microinjections of kainic acid (KA, 0.024 M) in 27 of the 42 cats. The resting SAP and blood flow of the three arteries were reduced by lesioning of the VLM more than that of the DM. Responses of SAP and blood flow from activation of the PR and VPR, particularly the latter, were affected more after DM compared to VLM lesioning. These data suggest that, while the pretentorial PAG constitutes the 'defence area,' vocalization is confined exclusively to its dorsolateral region and that both the VLM and DM contribute to the cardiovascular components of defence reactions. The DM appears to have a greater contribution compared to the VLM.

Animals↗
PubMed1997

Comparison of cytokeratin fragment 19 (CYFRA 21-1), tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA) as tumour markers in bronchogenic carcinoma.

To elevate the diagnostic value of the serum cytokeratin 19 fragment (CYFRA 21-1) and compare it with carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) in bronchogenic carcinoma, the sera of 161 patients (58 with benign pulmonary disease and 103 with bronchogenic carcinoma) was investigated using immunoradiometric assay. Sensitivities for CYFRA 21-1, CEA and TPA (using 3.5 ng ml-1, 5.0 ng ml-1, 110 U l-1, respectively, cut-off values corresponding to a 95% specificity for benign pulmonary disease) in bronchogenic carcinoma were 64, 47 and 61%, respectively. Positive CYFRA 21-1 levels were identified in 75% of patients with squamous cell carcinoma (n = 36), in 67% with adenocarcinoma (n = 45), in 17% with large cell carcinoma (n = 6), and in 50% with small cell lung cancer (SCLC) (n = 16). However, CYFRA 21-1 levels were not significantly different between squamous cell carcinoma and the other histological types. The sensitivity of the combined measurement of CYFRA 21-1 with any other tumour marker was significantly higher than that of CYFRA 21-1 measurement alone. Elevated CYFRA 21-1 levels were observed in 44% of Stages I and II (n = 18) and 72% of Stage III and IV (n = 69) patients with non-small cell lung cancer (P < 0.05). A significant inter-marker correlation was observed between CYFRA 21-1 and TPA (n = 103, r = 0.448, P < 0.0001). Twenty-one patients were monitored by CYFRA 21-1, and significantly different changes in progressive patients (P = 0.0058) and regressive patients (P = 0.016) were obtained. These results indicate that CYFRA 21-1 may be not only a sensitive tumour marker in the diagnosis of bronchogenic carcinoma, but also a useful marker for the monitoring of bronchogenic carcinoma.

Adenocarcinoma↗
PubMed1997

A conditional self-inactivating retrovirus vector that uses a tetracycline-responsive expression system.

We developed a novel conditional self-inactivating (C-SIN) vector, TL-SN, by replacement of the enhancer-promoter of the 3' long terminal repeat of Moloney murine leukemia virus with a synthetic tetracycline operator-cytomegalovirus promoter (tetP) from the tetracycline-responsive expression system (TRES). The other component of the TRES, a chimeric transactivator (tTA), was stably incorporated into PA317 amphotropic packaging cells, thus generating the packaging cell line PA317-tTA. C-SIN amphotropic G418-resistant virus particles were generated with a titer of 2 x 10(5) CFU/ml within 2 days of transinfection of PA317-tTA cells with TL-SN ecotropic virus particles. This titer was approximately 2 log units higher than that obtained by transinfection of parental PA317 cells and was due to the high level of viral transcripts originating from the tetP promoter at the 5' end of the transduced vector in the presence of tTA. Our C-SIN vector has the potential for use in human gene therapy since it incorporates the advantages of previous SIN vectors in having weak tetP promoter activity (in the absence of tTA in target cells) while at the same time achieving high viral titers with PA317-tTA packaging cells.

3T3 Cells↗
PubMed1997

Life-threatening scrub typhus with meningoencephalitis and acute respiratory distress syndrome.

A 21-year-old man presented with fever, rash, seizure, stiff neck and rapidly progressive bilateral pulmonary infiltrates. Cerebrospinal fluid (CSF) study revealed pleocytosis with predominant polymorphonuclear cells, and hypo-glycorrhachia. Status epilepticus occurred, followed by acute respiratory distress syndrome with respiratory failure. Blood and CSF cultures for bacteria were negative, but an indirect immunofluorescence assay revealed a fourfold rise in antibody to Rickettsia tsutsugamushi in paired serum and a 1:2560 (+) IgM antibody titer. Severe scrub typhus with meningoencephalitis and extensive pneumonitis was diagnosed. The patient survived after intravenous minocycline therapy and intensive care, including aggressive seizure control, supportive mechanical ventilation and avoidance of fluid overloading. He had a nearly complete recovery. Practicing physicians in Taiwan should be aware of this reportable disease and its potentially serious complications if not promptly diagnosed and treated.

Adult↗
PubMed1997

Penetration of the interatrial septum: a rare complication of percutaneous transluminal mitral commissurotomy.

Interatrial septal dissection and penetration into the aorta by a balloon catheter occurred in a 38-year-old man with mitral stenosis as a complication of percutaneous transluminal mitral commissurotomy during trans-septal puncture. It was speculated that the thickened septum was partially punctured into the potential space between the septa primum and secundum. Then, the balloon catheter went through the interatrial septum dissection into the aortic root. Emergency surgery was performed with the catheter left in situ. The surgical findings confirmed the speculated mechanism of this rare complication. In order to avoid this complication, the location of the tip of the Brockenbrough catheter after transeptal puncture must be confirmed. Checking the left atrial pressure tracing, arterial oxygenation and contrast injection are all important and indispensable procedures.

Adult↗
PubMed1997

The incidence of post dural puncture headache in Taiwanese patients undergoing cesarean section.

BACKGROUND: In Taiwan, there was only a retrospective study about the post-dural puncture headache (PDPH) resulting from spinal anesthesia for cesarean section (C/S), but it did not mention the relationship between the incidence of PDPH and the number of dural punctures, as well as between the gauge of spinal needle. Therefore, we designed a prospective study to investigate if the spinal needles for smaller gauges could decrease the incidence of PDPH in anesthesia for C/S. METHODS: From Jan. 1990 to June 1991 we prospectively observed 2,385 consecutive cases of spinal anesthesia for various types of surgical procedures, of which 584 were C/S. The spinal needles used were of gauges 24, 25 and 26. In practice, needles of these gauges were randomly applied. The PDPH was observed until its disappearance, and nonexistence of PDPH was also followed for at least one week. All of the data were analyzed using the Fisher exact test. RESULTS: The overall incidence of PDPH was 1.18%. The incidence of PDPH in C/S females was 3.08%, which was significantly higher than that in non-obstetric females (0.37%). Although the incidence in all females (1.31%) was significantly higher than that in males (0.71%), the incidence in non-obstetric females (0.37%) did not differ significantly compared with males. The incidence of PDPH relevant to the gauges of spinal needle used was not statistically different in C/S females. CONCLUSIONS: It appears that the incidence of PDPH does not differ between Taiwanese and Westerners. Pregnancy may be the key factor contributing to higher incidence of PDPH. The 26-gauge spinal needle may lower the incidence of PDPH to a greatest extent in C/S patients, although in comparison with 24- and 25-gauge needles the difference is not statistically significant.

Adolescent↗
PubMed1997

Post dural puncture headache in cesarean section: comparison of 25-gauge Whitacre with 25- and 26-gauge Quincke needles.

BACKGROUND: Our previous study showed that there were no significant differences in the incidence of post dural puncture headache (PDPH) relevant to the use of 24 to 26-gauge Quincke spinal needles in obstetric patients. Again, we were eager to know if the pencil-point spinal needle (Whitacre) would be able to decrease the incidence of PDPH compared to Quincke spinal needle. METHODS: We prospectively observed 94 spinal anesthesias for cesarean section performed during the period from May 1993 to July 1995. The 25-gauge Whitacre needles were used. In practice the insertion of needle was made through median line approach and the puncture was considered eligible only in one attempt. The PDPH was observed until its disappearance, and one without PDPH had also been observed for at least one week for likelihood of delayed occurrence. The data were compared with those of our previous study regarding the use of 25- and 26-gauge Quincke needles in obstetric patients. All of the data were analyzed using the Fisher exact test. RESULTS: The incidence of PDPH was 1.06%. In comparison there was no significant difference from that of 25- and 26-gauge Quincke needles (3.65% and 2.06%, respective). Only one case suffered from PDPH in the Whitacre group. It was mild and relieved with bed rest and hydration. CONCLUSIONS: Although the difference was not statistically significant, the 25-gauge Whitacre spinal needle caused a lower incidence and less severity of PDPH than the 25- and 26-gauge Quincke needles did.

Adult↗
PubMed1997

Heparin-binding epidermal growth factor-like growth factor and transforming growth factor-alpha in human non-small cell lung cancers.

Transforming growth factor-alpha (TGF-alpha), a member of the epidermal growth factor (EGF) family that binds to the EGF receptor (EGFR), is thought to function in an autocrine manner in non-small cell lung cancers (NSCLC). Heparin-binding EGF-like growth factor (HB-EGF), a novel member of the EGF family, also binds to EGFR. To compare the expression of HB-EGF, TGF-alpha and EGFR genes in NSCLC and normal lung tissue, we measured the levels of messenger RNA (mRNA) for these genes in human NSCLC and normal lung tissues by Northern hybridization, reverse transcription-polymerase chain reaction (RT-PCR), and in situ hybridization. A total of eight specimens (paired tumor tissue and normal lung tissue) were harvested from four patients who underwent resection of primary resectable NSCLC. HB-EGF was not expressed in either tumor tissue or normal lung tissue, while EGFR and TGF-alpha were expressed in all samples. TGF-alpha was overexpressed in all tumor tissue samples by several hundred-fold, while the expression of EGFR was not significantly different in tumor tissue and normal lung tissue. There was no correlation between the expression of TGF-alpha and EGFR. In situ hybridization showed that TGF-alpha mRNA was localized mainly in the cancer cells of tumor tissues and in the macrophages of alveoli in normal lung tissue. Our results showed that HB-EGF plays no role in the growth of NSCLC, and that there was no significant overexpression of EGFR in tumor tissue. TGF-alpha may play a major role in the growth of NSCLC. This supports a new direction in rational NSCLC treatment.

Carcinoma, Non-Small-Cell Lung↗
PubMed1996

Importance of left atrial appendage function as a risk factor for systemic thromboembolism in patients with rheumatic mitral valve disease.

One hundred fifty-six patients with rheumatic mitral valve disease were studied with transesophageal echocardiography to assess the influence of left atrial (LA) appendage size and contractile function on the occurrence of systemic embolism. LA appendage function, represented by peak emptying velocity, was found to be a better indicator than LA spontaneous echo contrast as a risk factor for systemic thromboembolism.

Adult↗
PubMed1996

A novel family of developmentally regulated mammalian transcription factors containing the TEA/ATTS DNA binding domain.

We describe the molecular cloning of two novel human and murine transcription factors containing the TEA/ATTS DNA binding domain and related to transcriptional enhancer factor-1 (TEF-1). These factors bind to the consensus TEA/ATTS cognate binding site exemplified by the GT-IIC and Sph enhansons of the SV40 enhancer but differ in their ability to bind cooperatively to tandemly repeated sites. The human TEFs are differentially expressed in cultured cell lines and the mouse (m)TEFs are differentially expressed in embryonic and extra-embryonic tissues in early post-implantation embryos. Strikingly, at later stages of embryogenesis, mTEF-3 is specifically expressed in skeletal muscle precursors, whereas mTEF-1 is expressed not only in developing skeletal muscle but also in the myocardium. Together with previous data, these results point to important, partially redundant, roles for these TEF proteins in myogenesis and cardiogenesis. In addition, mTEF-1 is strongly coexpressed with mTEF-4 in mitotic neuroblasts, while accentuated mTEF-4 expression is also observed in the gut and the nephrogenic region of the kidney. These observations suggest additional roles for the TEF proteins in central nervous system development and organogenesis.

Amino Acid Sequence↗
PubMed1996

Low-serum, high-density lipoprotein cholesterol concentration is an important coronary risk factor in Chinese patients with low serum levels of total cholesterol and triglyceride.

The significance of low-serum high-density lipoprotein concentrations (<35 mg/dl) with respect to coronary atherogenesis in Chinese patients with low levels of total serum cholesterol (<200 mg/dl) and triglycerides (<250 mg/dl) was assessed. Persons with such a lipid profile pattern were still at high risk, and high-density lipoprotein. like smoking, appeared to be the most predictive independent coronary risk factor.

Adult↗