Biomedical subjects

J J Han

Publications and source records attributed to J J Han.

At least 19 recordsLinked to original sources

PubMed1997

Abnormal morphological patterns of the left ventricular myocardium in the critical stenosis of the aortic valve and the intact ventricular septum.

The evaluation of prognostic factors in infants with critical stenosis of the aortic valve and intact ventricular septum is often misleading due to a complex interaction among lesions in the mitral and aortic valves, and the left ventricular myocardium. The clinical parameters on the left ventricular function, such as ejection fraction and left ventricular end-diastolic volume, are of particular interest as their effects on survival are very controversial. We performed a clinicopathologic analysis of two autopsied cases of this disease. Besides the morphological hallmarks of the aortic and mitral valves, these two cases showed two extreme types of pathology in the left ventricular myocardium, which might have significant impacts on the clinical evaluation of the left ventricular function. Case 1 showed endocardial fibroelastosis associated with abnormal intertrabecular spaces (so-called spongy myocardium), obscuring accurate estimation of the left ventricular end-diastolic volume. Case 2 showed ischemic necrosis of the apical part of the left ventricular myocardium. This infarct was associated with acute and chronic subendocardial ischemia and mild endocardial fibroelastosis. Aggravation of the left ventricular failure could be caused by the recent ischemic insult. The evaluation of the left ventricular function, therefore, should include the evaluation of the morphologic status of the myocardium as regards to whether there is ischemia, endocardial fibroelastosis or hypertrophied trabeculae in addition to stenotic lesions in the aortic and mitral valves.

Aortic Valve Stenosis↗

PubMed1996

Circulating antigens in schistosomiasis: detection of 31/32-kDa proteins in sera from patients infected with Schistosoma japonicum, S. mansoni, S. haematobium, or S. intercalatum.

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to detect 31/32-kDa schistosome proteins as circulating antigens in sera from schistosomiasis patients. A monoclonal antibody was used as a capture antibody and rabbit antiserum raised against purified 31/32-kDa proteins was the detecting antibody. Positive results were obtained with patients infected with Schistosoma japonicum (88%; n = 69), S. mansoni (80%; n = 56), S. haematobium (100%; n = 40), or S. intercalatum (94%; n = 65). Sera from uninfected Chinese and African individuals and from Chinese patients with trichinosis, cysticercosis, or paragonimiasis did not react in the assay. This ELISA appears to be valuable in diagnosing infections by all major human schistosome species.

Adolescent↗

PubMed1996

Left subclavian artery bypass graft in complicated arterial switch operation.

We report the successful use of left subclavian artery bypass graft in a newborn infant with complete transposition of the great arteries accompanied by an unusual coronary artery pattern, in whom left coronary artery insufficiency developed after the arterial switch operation. This procedure has shown good clinical results, with interesting follow-up angiographic findings 8 months after the operation.

Coronary Angiography↗

PubMed1996

Evaluation of a monoclonal antibody-based sandwich-ELISA for detection of circulating Schistosoma japonicum antigen (Sj31/32) in an endemic area of China.

A sandwich-ELISA specific for 31/32 kDa schistosome proteins was used to trace infections in a Chinese population living in a low endemicity area for schistosomiasis japonica. The study population included 304 persons for whom records were available from 1992 onwards. In 1994, 2 individuals were positive in the miracidial hatching assay performed with 30 g of stools. The ELISA gave positive results for 8 individuals, including these 2 with active infections. Of the remaining 6 ELISA-positive, 5 had excreted eggs and received praziquantel in 1993 and may have harboured residual worms in 1994. It is concluded that this ELISA is able, in a low prevalence situation, to identify the few infected individuals.

Adolescent↗

PubMed1994

Isolated left main coronary ostial stenosis: intraoperative transesophageal echocardiography during surgical angioplasty.

OBJECTIVE: We hypothesized that transesophageal echocardiography could be used to image the repair of a left ostium or main coronary artery following surgical angioplasty. METHODS AND RESULTS: Six patients, all women, were found to have isolated left main coronary ostial stenosis. We performed preoperative transesophageal echocardiography (TEE) in three and intraoperative TEE in four of six patients. Their mean age was 48 years. They presented with severe angina (Class III or IV) with a short duration (6.8 +/- 7.8 months). They had a low incidence of risk factors while histopathologic examinations showed typical atherosclerosis in all four patients. Preoperative two-dimensional echocardiography demonstrated left main coronary ostial stenosis in three patients. We clearly observed the patency of the pericardial or saphenous venous patch with basal short-axis scan on two-dimensional and color Doppler echocardiography in all four patients after weaning them from cardiopulmonary bypass and finished operation without complications. CONCLUSIONS: Our study shows that TEE can be used to image the repair of a left ostium or main coronary artery following surgical angioplasty and provide the surgeon with the required information about the adequacy of the repair.

Coronary Disease↗

PubMed1994

Release of endothelin in relation to tumor necrosis factor-alpha in porcine Pseudomonas aeruginosa-induced septic shock.

Septic shock is characterized by surges of tumor necrosis factor-alpha (TNF-alpha) along with myocardial dysfunction and systemic hypotension. TNF-alpha promotes the release of immunoreactive endothelin (ET). Because TNF-alpha is elevated in septic shock, we hypothesized that elevated levels of endothelin can contribute to cardiac dysfunction and hypotension. We infused live Pseudomonas aeruginosa into anesthetized, hemodynamically monitored young swine and measured ET and TNF-alpha. Septic swine developed systemic arterial hypotension and had significantly elevated TNF-alpha (4.15 +/- .41 U/ml at 1 h versus .40 +/- .13 U/ml at time zero) compared to control animals. ET levels were significantly elevated at 4 h (52.38 +/- 12.88 pg/ml vs. 10.45 +/- 1.82 pg/ml at time zero) and correlated negatively with the decline in cardiac output. We then passively immunized swine using anti TNF-alpha prior to the induction of sepsis to examine if TNF played a central role in the release ET. The anti TNF-alpha effectively removed circulating TNF-alpha bioactivity in septic animals. Anti-TNF-alpha-treated animals did not develop significant systemic arterial hypotension and had significant attenuation in endothelin (19.01 +/- 4.18 pg/ml at 4 h compared to 52.38 +/- 12.88 pg/ml in septic animals at 4 h) which correlated with preservation of cardiac output. TNF-alpha may cause cardiac dysfunction in sepsis syndrome through increased release of ET.

Animals↗

PubMed1994

Nationwide survey of human parasite in China.

A nationwide survey of human parasites in China was conducted during 1988-1992, with a coverage of 30 provinces/autonomous regions/municipalities (P/A/M). A total of 2,848 pilot sites in 726 counties were selected by random sampling, and 1,477,742 individuals residing on were surveyed by fecal examination. The status of paragonimiasis, hydatid diseases, cysticercosis and trichinellosis were summarized through data review. The overall infection rate of intestinal parasites was 62.6% whereas at provincial level, the highest infection rate (94.7%) was recovered in Hainan, and the lowest (17.5%) in Heilong-jiang. A high proportion (43.3%) of polyparasitism among the infected population (882,080) was revealed. Altogether 56 species of parasites comprising protozoa (19), trematode (16), cestodes (8), nematodes (12) and thorny-headed worm (1) were discovered. During the survey a new species and several new records were documented. The number of the population infected with common intestinal parasites was estimated. The diversities of parasite distribution were noted in different nationalities as well as in varied occupations.

Adolescent↗

PubMed1994

Detection of Schistosoma japonicum antigen (Sj31/32) in sera of Chinese patients using a sandwich ELISA based on monoclonal antibody.

A sandwich-ELISA was developed using IgG from rabbits infected with Schistosoma japonicum as capture antibody and a monoclonal antibody as detecting reagent for circulating Sj 31/32 in patient sera. The assay detected circulating antigen in 36 of 53 sera from Chinese schistosomiasis japonica patients, but not in sera from healthy persons or patients with paragonimiasis, trichinosis or cysticercosis. This is the first demonstration that Sj 31/32 proteins may be used for circulating antigen-based serodiagnosis of schistosomiasis.

Animals↗

PubMed1993

Isolated left main coronary ostial stenosis in Oriental people: operative, histopathologic and clinical findings in six patients.

OBJECTIVES: This study was performed to determine whether there are differences in the operative, histopathologic, angiographic and clinical findings of isolated ostial stenosis between Oriental and western patients. BACKGROUND: Angiographic, clinical and histologic findings in isolated ostial stenosis have been reported in western but not in Oriental patients. METHODS: Six patients, all women (0.88% of a total of 684 patients who underwent coronary angiography between March 1989 and July 1991), were found to have isolated left main coronary ostial stenosis. We performed surgical ostial angioplasty with the autologous pericardial or saphenous venous patch and biopsy at the aortic arteriotomy site in four of the six patients. RESULTS: All six patients presented with severe angina (angina class III or IV) of short duration (mean +/- SD 6.2 +/- 6.2 months) and had a very low incidence of risk factors, although histopathologic examination showed typical atherosclerosis in four of the six patients. They were young to middle-aged women (mean 45 +/- 3 years) except for Patient 6 (62 years). Exercise duration was short and ST segment depression, accompanied by typical angina, was observed in many leads in the warm-up period or stage I. Despite the crucial location of the lesion, most patients had well preserved left ventricular function and normal wall motion. There was no angiographically definable collateral circulation from either ipsilateral or contralateral vessels except for grade I collateral circulation in Patient 5. Operative findings demonstrated mostly yellow atheroma in the aortic wall and left coronary ostium. Coronary angiography showed only ostial stenosis of the left coronary artery in all six patients, but operative findings documented atheromatous change in the left main coronary artery in two of the six. CONCLUSIONS: The clinical, angiographic, histopathologic and operative findings of Oriental patients were similar to those reported in western patients, but the incidence of isolated left main coronary ostial stenosis was higher in the Oriental group. Angiographically definable isolated coronary ostial stenosis may often not be true isolated ostial stenosis.

Cardiac Catheterization↗

PubMed1993

Immunization of pigs against infection with Schistosoma japonicum using ultraviolet-attenuated cercariae.

Since pigs are important in the zoonotic transmission of schistosomiasis japonica in China, a veterinary vaccine might contribute to the control of the disease in humans. Pigs were immunized with three doses each of 10,000 cercariae of Schistosoma japonicum attenuated with ultraviolet light (400 microWatt.min/cm2). The experiment was performed with portable irradiation equipment in a rural area of the Hubei Province (P.R. China). A challenge infection of 1,000 untreated cercariae was given 2.5 or 6 months after the last immunization, and age-matched naive pigs were challenged as a control. Immunized pigs developed about 90% resistance against the challenge. The liver egg load of these animals was reduced by over 90%. Less than 0.01% of the immunizing cercariae developed to adult parasites and the vaccination had no apparent adverse influence on the pigs' health.

Animals↗

PubMed1990

Schistosoma japonicum: an ultraviolet-attenuated cercarial vaccine applicable in the field for water buffaloes.

Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The irradiation was performed with cheap, simple, and portable equipment in a rural area of Hubei Province (People's Republic of China). A challenge infection of 1000 untreated cercariae was given to six vaccinated and six naive control buffaloes, while two vaccinated animals were not challenged. The experiment was terminated 6 weeks after the challenge. Control animals had lost body weight and harbored a mean of 110 worms and 37 eggs per gram of liver. The vaccinated animals gained weight after the challenge and developed 89% resistance to infection with S. japonicum. Since schistosomiasis japonica is nowadays transmitted in China predominantly by domestic livestock, a uv-attenuated cercarial vaccine for bovines may contribute to the control of this disease.

Animals↗

PubMed1988