Sequence polymorphisms in Pvs48/45 and Pvs47 gametocyte and gamete surface proteins in Plasmodium vivax isolated in Korea

Nucleotide sequence analyses of the Pvs48/45 and Pvs47 genes were conducted in 46 malaria patients from the Republic of Korea (ROK) (n = 40) and returning travellers from India (n = 3) and Indonesia (n = 3). The domain structures, which were based on cysteine residue position and secondary protein structure, were similar between Plasmodium vivax (Pvs48/45 and Pvs47) and Plasmodium falciparum (Pfs48/45 and Pfs47). In comparison to the Sal-1 reference strain (Pvs48/45, PVX_083235 and Pvs47, PVX_083240), Korean isolates revealed seven polymorphisms (E35K, H211N, K250N, D335Y, A376T, I380T and K418R) in Pvs48/45. These isolates could be divided into five haplotypes with the two major types having frequencies of 47.5% and 20%, respectivelfy. In Pvs47, 10 polymorphisms (F22L, F24L, K27E, D31N, V230I, M233I, E240D, I262T, I273M and A373V) were found and they could be divided into four haplotypes with one major type having a frequency of 75%. The Pvs48/45 isolates from India showed a unique amino acid substitution site (K26R). Compared to the Sal-1 and ROK isolates, the Pvs47 isolates from travellers returning from India and Indonesia had amino acid substitutions (S57T and I262K). The current data may contribute to the development of the malaria transmission-blocking vaccine in future clinical trials.

Evaluation of a malaria antibody enzyme immunoassay for use in blood screening

Transfusion-transmitted malaria is rare, but it may produce severe problem in the safety of blood transfusion due to the lack of reliable procedure to evaluate donors potentially exposed to malaria. Here, we evaluated a new enzyme-linked immunosorbent assay malaria antibody test (ELISA malaria antibody test, DiaMed, Switzerland) to detect antibodies to Plasmodium vivax (the indigenous malaria) in the blood samples in the Republic of Korea (ROK). Blood samples of four groups were obtained and analyzed; 100 samples from P.vivax infected patients, 35 from recovery patients, 366 from normal healthy individuals, and 325 from domestic travelers of non-endemic areas residents to risky areas of ROK. P.vivax antibody levels by ELISA were then compared to the results from microscopic examination and polymerase chain reaction (PCR) test. As a result, the ELISA malaria antibody test had a clinical sensitivity of 53.0 percent and a clinical specificity of 94.0 percent for P.vivax. Twenty out of 325 domestic travelers (6.2 percent) were reactive and 28 cases (8.6 percent) were doubtful. Of the reactive and doubtful cases, only two were confirmed as acute malaria by both microscopy and PCR test. Thus we found that the ELISA malaria antibody test was insufficiently sensitive for blood screening of P.vivax in ROK.

Apoptotic Neuronal Death in the Mouse Brain Induced by Experimental Japanese Encephalitis Virus Infection / 대한해부학회지

Japanese encephalitis virus (JEV)may cause acute encephalitis in humans and induce severe cytopathic effects in various types of cultured cells. To investigate whether JEV infection induces apoptosis, we examined DNA fragmentation and apoptosis in the specific region of the JEV infected mouse brain by DNA oligonucleosomal laddering and in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)technique and immunohistochemical study. JEV infections in the mouse brain were detected in the telencephalon, the diencephalons, and the brain stem, but not in the cerebellum and the hippocampus. Fragmentation of cellular DNA into oligonucleosome-length ladders was only observed in tissue samples prepared from the cerebral cortex. In addition, the large number of TUNEL-positive cells was observed in the cerebral cortex. Double-labeling experiment with TUNEL staining and immunostaining for the JEV showed that TUNEL-positive neurons containing JEV immunoreactivity. These results suggest that JEV infection may evoke apoptotic neuronal death in the mouse brain, which plays an important role in the pathogenesis of Japanese encephalitis.

In vivo Study on the Japanese Encephalitis: Viral Localization and Histopathology in the Mouse Brain / 대한해부학회지

Japanese encephalitis is a potentially lethal disease of the central nervous system caused by infection with Japanese encephalitis virus (JEV). JEV is the most common cause of encephalitis over a large part of eastern Asia. To establish and characterize in vivo model to study the Japanese encephalitis, the immunohistochemical localization of JEV and the histopathological finding were investigated in the brains of young adult mice infected with JEV by intraperitoneal inoculation. JEV was localized to neurons in discrete regions of the brain. Histopathological finding showed typical pattern of acute viral encephalitis, such as inflammatory cell infiltration in brain parenchyme and perivascular cuffs of mononuclear cells. These results suggest that this in vivo system can be used to study the mechanism of virus entry into the brain, cell specific tropism, and pathophysiology in Japanese encephalitis.

Study on Effect of Conjugated Equine Estrogen and Progestogen on Serum Lipid Profiles and Bone Mineral Density in Postmenopausal Women / 대한산부인과학회잡지

Hormone replacement therapy combined with progestogens induces changes in effect of estrogen on serum lipid levels and it has been known that the changes depend on a type and dosage of progestogen. It is also known that progestational agent induces positive ch-ange in bone mineral density. To study the effects of progestogen on lipoprotein and bone metabolism, we administ- ered conjugated equine estrogen 0.625 mg alone to 50 postmenopausal women, in combinat- ion with medroxy- progesterone acetate 5 mg to 40 postmenopausal women. The data demonstrated a beneficial effect in lipoprotein profiles in both groups. Total cholesterol in two groups decreased from the baseline values, LDL-cholesterol decreased significantly by 4.8 % in group I and 16.2 % in group II(p < 0.05), HDL-cholesterol increa- sed significantly by 11.3 % in group I and 14.7 % in group II(p < 0.05), triglyceride incre- ased slightly in both groups. Bone mineral density of femur was maintained and BMD of vertebrae increased by 1.1 % in group I and 2.0 % in group II, but it is not statistically significant. The differences of changes between two groups were not statistically significa- nt. Our results suggest that medroxyprogesterone acetate have no adverse effect on HDL -cholesterol and have no additive effect on bone mineral density in hormone replacement therapy.

Analysis of the Three Dimensional Structure of Envelope Protein of the Japnes Encephalitis virus Isolated in Korea

Three dimensional structures of envelope protein from Korean isolates and Nakayama-NIH strain of Japanese encephalitis virus (JEV) were deduced by a computer program (HyperChem 4.0 Chemplus 1.0) based on the data of the three dimentional structure of Tick-borne encephalitis virus. In the three dimensional structure of envelope protein, neutralizing epitope and T-helper cell recognition site of C-terminal region of Korean isolates were structually similar to those of Nakayama-NIH but the N-terminal region was not. Korean JE isolates were compared with Nakayama-NIH strain by using cross-neutralization antibody test. Neutralizing activities of Korean isolates derived from guinea pigs were higher than those of Nakayama-NIH strain against Korean isolates, although the polyclonal antibody titers of Nakayama-NIH showed 1:160 to 1:640 against Korean isolates. According to the results from three dimentional structures and cross-neutralization analyses, the antigenic difference between Korean JE isolates and Nakayama-NIH strain may be dependent on structural difference of envelope protein.

Immunohistochemical Study on nm23 Protein Expression in Carcinoma of the Uterine Cervix / 대한산부인과학회잡지

The nm23 gene was originally identified by differential screening of a cDNA library with RNA from low and high metastatic clones of a murine melanoma cell line. And the nm23 gene has been represented as a metastasis suppressor gene. The product of nm23 gene is known to be identical to nucleoside diphosphate(NDP) kinase. The lack of expression of nm23 protein has been correlated with a poorer prognosis in some human tumors, among which are breast carcinoma, malignant melanoma, gastric carcinoma and hepatcelluar cacin-oma. However, in several types of malignant tumors such as colon carcinoma, neuroblastoma and pancreatic carcinoma, unexpected overexpression of nm23 protein was found as compared with normal tissues. Also in a few studies with cervical carcinoma, the expression of nm23 protein was found to be increased as compared with normal cervical tissue recently. Therefore, in this study, we analyzed the expression of nm23-H1 protein by immunohistochemistry method in a series of 40 cervical carcinomas, to determine whether the alterations in the expression of nm23-H1 protein occured in cervical carcinoma as compared with cervical intraepithelial neoplasia(CIN) and normal cervices, and also analyzed the possible association between nm23 protein expression and prognostic parameters of cervical carcinoma at Ewha Womans University Mokdong Hospital from September 1993 to March 1997. The results obtained were as follows; 1. The mean ages of normal control patients, CIN and cervical carcinomas were 42.9 (+/-5.1) years, 39.5(+/-7.7) years, and 49.3(+/-11.7) years respectively. All cases of cervical carcinoma were squamous cell carcinomas. And the number of each stages Ia, Ib, IIa, IIb, III and IV were 13 cases, 8 cases, 6 cases, 9 cases, 2 cases, and 2 cases respectively. 2. In cervical carcinoma, nm23-H1 protein expression was significantly increased as compared with CIN and normal cervical tissue(t=5.017>1.96). 3. In cervical carcinoma, the nm23-H1 protein expression was more increased in higher stages(p=0.021). But it had no significant correlations with primary tumor size, lymphovascular space invasion, parametrial invasion or lymph node metastasis. Our results on nm23-H1 protein expression in cervical carcinoma suggest that cervical carcinoma seems to belong to the group of tumors, like colon carcinoma and neuroblastoma, pancreatic carcinoma in which nm23-H1 overexpression is associated with a more malignant phenotype. In this study, nm23-H1 protein was more expressed in higher clinical stages of cervical carcinoma. Therefore the expression of nm23-H1 protein probably may have a prognostic significance in cervical carcinoma. But a further prospective study on a larger population is needed to establish the role of nm23 gene in this kind of tumor.