Variation of antigenicity and serological reaction to Pneumocystis carinii in Korea

The present study observed the variation of antigenicity of Pneumocystis carinii and serum IgG antibody reaction to the antigens from different localities in Korea. Antigens of rat P. carinii and sera of inhabitants were collected at Chunchon. Chungju, Kwangju, and Seoul during 1995-1996. Enzyme-linked Immunosorbent Assay and immunoblot were used for immune reaction. Absorbance of 1,294 human sera ranged between 0.01 and 0.93. Sera from Chunchon showed higher absorbances than those from other areas. Immunoblotting revealed IgG antibody reactions to 116, 100, and 45-55 kDa antigenic bands of rat P. carinii, but the frequencies of positive reaction to individual bands were variable by localities. Total 62.6% of the sera showed the reaction to 116 kDa band while 37.7% reacted to 100 kDa band and 32.0% to 45-55 kDa bands. For the reaction to 116 kDa, the reaction rate was 60.0% to 82.6% by localities. It is found that the reaction rates of the human sera to rat P. carinii antigen are variable according to the localities. Also, the high molecular antigen of 116 kDa of rat P. carinii is the most frequent antigenic band reacting to human sera.

Infection status of dragonflies with Plagiorchis muris metacercariae in Korea

Plagiorchis muris has been found in both house and field rats as well as in humans. The infection status of the second intermediate hosts of P. muris is prerequisite in understanding their biological features in an ecosystem. Six species of dragonflies were caught in a wide range of areas in Korea; and they were Sympetrum darwinianum, S. eroticum, S. pedomontanum, S. infuscatum, Pantala flavoscens, Calopteryx atrata, and Orthetrum albistylum speciosum. The occurrence of P. muris metacercariae in dragonflies was nationwide with various infection rates. The metacercarial burden of P. muris in the surveyed areas was the highest in S. eroticum followed by S. darwinianum, S. pedomontanum, and C. atrata. The highest infection rate by P. muris metacercariae was found in S. darwinianum followed by S. eroticum. The metacercarial burden was particularly heavy in the dragonflies found in Hamyang-gun and Kosong-gun, Kyongsangnam-do. It is, therefore, likely that dragonflies play a significant role as the second intermediate host in the life cycle of P. muris in Korea.

Hybrid estimation of navigation parameters from aerial image sequence

This work presents a hybrid method for navigation parameter estimation using sequential aerial images, where navigation parameters represent the position and velocity information of an aircraft for autonomous navigation. The proposed hybrid system is composed of two parts: relative position estimation and absolute position estimation. Computer simulation with two different sets of real aerial image sequences shows the effectiveness of the proposed hybrid parameter estimation algorithm.

Karyotype analysis of Neodiplostomum seoulense

A karyotype analysis of the chromosome of Neodiplostomum seoulense, one of causative agents of human intestinal trematodiasis, was done from the gonad tissue by the squashing method. The chromosome number was n = 10 and 2n = 20. Chromosome length was 1.30-4.0 microns. Chromosome pairs in the complement consisted of two pairs of metacentric, five pairs of submetacentrics/subtelocentric and three pairs of telocentric chromosomes. These data were comparable with those of other intestinal trematodes.

Characterization of staphylococcal bovine mastitis isolates using the polymerase chain reaction

A polymerase chain reaction (PCR) assay was adapted to detect toxin genes of staphylococcal isolates from cases of bovine mastitis. Samples were obtained from three geographical areas: Korea and Idaho and Washington in the northwest United States. Samples from Korea and Washington were randomly chosen. Idaho samples were from a prospective study of mastitis etiology. Forty-one milk samples from 25 commercial farms in south-central Idaho were collected from cows with symptoms of mastitis. Although Staphylococcus aureus constituted 37.5% of mastitis isolates, these isolates lacked genes for staphylococcal enterotoxins (SEs), toxic shock syndrome toxin, and exfoliative toxins. In contrast, 4 of 13 isolates from Washington and 6 of 20 isolates from South Korea expressed SEs. These results suggest that PCR may be an effective means of screening bovine isolates for toxins. They also emphasize the potential for significant geographic differences in mastitis etiology.

Fractal coding of video sequence using circular prediction mapping and noncontractive interframe mapping

We propose a novel algorithm for fractal video sequence coding, based on the circular prediction mapping and the noncontractive interframe mapping. The proposed algorithm can effectively exploit the temporal correlation in real image sequences, since each range block is approximated by the domain block in the adjacent frame, which is of the same size as the range block. The computer simulation results demonstrate that the proposed algorithm provides very promising performance at low bit rate, ranging from 40-250 kbyte/s.

A fractal vector quantizer for image coding

We investigate the relation between VQ (vector quantization) and fractal image coding techniques, and propose a novel algorithm for still image coding, based on fractal vector quantization (FVQ). In FVQ, the source image is approximated coarsely by fixed basis blocks, and the codebook is self-trained from the coarsely approximated image, rather than from an outside training set or the source image itself. Therefore, FVQ is capable of eliminating the redundancy in the codebook without any side information, in addition to exploiting the self-similarity in real images effectively. The computer simulation results demonstrate that the proposed algorithm provides better peak signal-to-noise ratio (PSNR) performance than most other fractal-based coders.

Genetic comparison between Spirometra erinacei and S. mansonoides using PCR-RFLP analysis

The only observed morphological difference between Spirometra erinacei and S. mansonoides is the uterine shape of the mature proglottid. Two species of worms are thought to be evolutionarily closely related. Biomolecular comparison of the two worms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was conducted to observe the genetic distance. The 28s rDNA, mitochondrial cytochrome c oxidase subunit I (mCOI), and ribosomal internal transcribed spacer 1 (ITS1) fragments were obtained from the worms by PCR. The PCR products were cleaved by 5 four-base pair restriction enzyme combinations (Msp I, Hae III, Alu I, Cfo I, Rsa I), electrophoresed and analyzed with PAUP 3.1.1. The fragment patterns of 28S rDNA and ITS1 demonstrated that two worms were in identical systematic tree with bootstrap number 94 and 100, respectively. As for mCOI, bootstrap number was 74 in a different tree. Above results are indicative of recent common ancestry between S. erinacei and S. mansonoides.

Localization of worm antigen in Neodiplostomum seoulense by immuno-electronmicroscopy

The localization of worm antigen of Neodiplostomum seoulense was examined by immuno-electronmicroscopic observation. Not only the immunized serum of mice with crude worm extract of N. seoulense but also serum of infected mouse were reacted to the worm section. Using immunized serum as primary antibody, the gold particles were deposited on the rough endoplasmic reticulum of the cell of tribocytic organ, spermatozoa in the seminal vesicle, microvilli of the caecum and vitelline follicle. Using infected serum, gold particles were deposited only on the vitelline follicle prominently. This finding suggested that the tribocytic organ, seminal vesicle, caeca and vitelline follicles may play a role of antigen to immunized serum with crude worm extract of N. seoulense, whereas the vitelline follicle, to the infected serum.

Molecular typing and epidemiological survey of prevalence of Clostridium perfringens types by multiplex PCR

Clostridium perfringens has been classified into five toxigenic types (A through E) on the basis of its capability to produce major lethal toxins (alpha, beta, epsilon, and iota toxins). Seroneutralization with mice or guinea pigs has been used to type each toxin, but this conventional method has some disadvantages. Therefore, we used a molecular biological technique to type the bacterium in the present study. A multiplex PCR was developed for this purpose. This method has several advantages in comparison with seroneutralization with mice or guinea pigs. By this method, we also investigated the most prevalent type(s) of the organism in Korean calves, piglets, and chickens showing clinical symptoms such as diarrhea, enterotoxemia, and necrotic enteritis. Only type A was isolated from calves and chickens, while type C (2 of 14 isolates), in addition to type A, was isolated from piglets. These results suggested that seroneutralization could be replaced by our new method and that type A of C. perfringens is the most prevalent type in livestock in Korea.

On testing trained vector quantizer codebooks

This paper discusses a criterion for testing a vector quantizer (VQ) codebook that is obtained by "training". When a VQ codebook is designed by a clustering algorithm using a training set, "time-average" distortion, which is called the training-set-distortion (TSD), is usually calculated in each iteration of the algorithm, since the input probability function is unknown in general and cumbersome to deal with. The algorithm stops when the TSD ceases to significantly decrease. In order to test the resultant codebook, validating-set-distortion (VSD) is calculated on a separate validating set (VS). Codebooks that yield small difference between the TSD and the VSD are regarded as good ones. However, the difference VSD-TSD is not necessarily a desirable criterion for testing a trained codebook unless certain conditions are satisfied. A condition that is previously assumed to be important is that the VS has to be quite large to well approximate the source distribution. This condition implies greater computational burden of testing a codebook. In this paper, we first discuss the condition under which the difference VSD-TSD is a meaningful codebook testing criterion. Then, convergence properties of the VSD, a time-average quantity, are investigated. Finally we show that for large codebooks, a VS size as small as the size of the codebook is sufficient to evaluate the VSD. This paper consequently presents a simple method to test trained codebooks for VQ's. Experimental results on synthetic data and real images supporting the analysis are also provided and discussed.

Combined cis-platinum and alpha interferon therapy of advanced hepatocellular carcinoma

To evaluate the clinical efficacy of alpha-interferon(IFN-alpha) plus cis-platinum in hepatocellular carcinoma(HCC). 56 inoperable patients with HCC were divided into IFN-alpha plus cis-platinum treated group (n = 30) and no antitumor therapy group (n = 26). The survival of IFN-alpha plus cis-platinum treated patients was significantly better than that of patients who received no antitumor therapy (p = 0.001). Median survival time was 33 weeks and 14.0 weeks, respectively. The cumulative estimated survival rates of our IFN-alpha plus cis-platinum treated group (93.5% at 3mo, 75.0% at 6mo) were for longer than that of the no antitumor therapy group (84.6% at 3mo, 57.7% at 6mo). Objective tumor regression, greater than 50% was observed in 13.3% (4 of 30) of patients receiving IFN-alpha plus cis-platinum. By the univariate analysis, the absence of portal vein thrombus (p < 0.05), alkaline phosphatase lesser than 280 U/L (p = 0.001), total bilirubin less than 2.0 mg% (p < 0.05), serum triglyceride less than 155 mg/dl (p < 0.05) were shown to be the factors most significantly favoring a better survival. By the multivariate analysis, using Cox proportional hazards model, IFN-alpha plus cis-platinum treated group (p = 0.0001), alkaline phosphatase less than 280 mg/dl (p = 0.005), the absence of portal vein thrombus (p = 0.020) were independent favorable prognostic factors. We conclude that IFN-alpha plus cis-platinum is useful in patients with inoperable HCC and the above favorable prognostic factors may also be useful in the design and analysis of future clinical trials of systemic chemotherapy for HCC.

IgA response in mice infected with Neodiplostomum seoulensis

To observe the production of IgA in Balb/c mice with neodiplostomiasis, 20 mice were infected with each 200 metacercariae of Neodiplostomum seoulenis. Sera and the duodenums were obtained 3, 7, 14, 28 days post-infection (PI) from five mice each group. Neodiplostomum specific IgA in serum by the enzyme-linked immunosorbent assay increased from 7 days PI and persisted till 28 days PI. Immunohistochemistry for IgA was done with sections of the duodenum. The IgA-positive reaction was generally seen in the lamina propria and submucosa. Some of epithelial cells were positive at 7 and 14 days PI. The present finding showed that Neodiplostomun specific IgA antibody increased in serum and that there was local reaction of IgA in the mucosa and submucosa of the duodenum but not directly related with worm expulsion.

Intestinal trematode infections in the villagers in Koje-myon, Kochang-gun, Kyongsangnam-do, Korea

An epidemiological study for the intestinal trematode infection of the villagers was done in Koje-myon, Kochang-gun, Kyongsangnam-do, Korea in March, 1994. Of 116 stool specimens examined, total helminthic ova positive cases were 13 (11.2%) and cumulative ova positive cases 21 (18.1%): Echinostoma hortense 11 cases (9.5%), Metagonimus sp. 6 cases (5.2%), and Clonorchis sinensis 4 cases (3.4%). After the treatment and purgation, variable numbers of E. hortense, 6 to 227 per person, were collected from 7 echinostome egg positive cases, together with M. takahashii in 6 cases. Three adult flukes of E. cinetorchis were collected from one person and one Stellantchasmus falcatus was recovered from another case. This mountainous village was proved to be one of the endemic foci of echinostomiasis in Korea.

A follow-up examination of intestinal parasitic infections of the Army soldiers in Whachon-gun, Korea

A follow-up stool examination was done to know the status of intestinal parasitic infections in Army soldiers who were stationing in Whachon-gun, Kangwon-do, Korea in 1993. Of 233 examined soldiers, Infections with Clonorchis sinensis (0.4%), Metagonimus spp. (0.9%), Echinostoma hortense (0.4%), Neodiplostomum seoulensis (0.4) and Giardia lamblia (3/233) were found. E. hortense and N. seoulensis infections were each 75th, and 27th cases in Korea. Regular control program of intestinal parasitic infections might be able to contribute to diminish the prevalence rate in young Army soldiers in Korea.

Intestinal parasite infections in the inhabitants along the Hantan River, Chorwon-gun

The prevalence of intestinal parasite infections in inhabitants at the reaches of the Hantan River, Chorwon-gun, Korea, was observed from August 12 to September 14, 1993. Of 465 people observed by cellophane thick smear and formalin-ether concentration method, 2 Ascaris lumbricoides (unfertilized), 1 Trichuris trichiura, 39 Clonorchis sinensis and 16 Metagonimus egg positive cases were found. After treatment, the Metagonimus egg positive cases passed out flukes of Metagonimus Miyata type. Of 68 fish caught in the Hantan River, 14 (20.6%) were infected with metacercariae of Metagonimus, while no metacercaria of C. sinensis was found. At this area, soil-transmitted nematodes are very low, but clonorchiasis and metagonimiasis are prevalent by modernate endemicity.

Effect of adenine arabinoside and alpha-interferon in patients with HBeAg-positive chronic active hepatitis

To evaluate and compare the therapeutic efficacy of adenine arabinoside (Ara-A) and alpha-interferon (alpha-INF), 40 patients with biopsy proven chronic active hepatitis B were chosen at random to receive Ara-A (15 mg/Kg, iv, for 10 day) or alpha-INF (3 million unit, sc, every other day for 12 wks) and followed up to 12 months after completion of the therapy. All patients were HBeAg positive. The clinical effects of Ara-A and alpha-INF on seroconversion of HBeAg positive. The clinical effects of Ara-A AND alpha-INF on seroconversion of HBeAg and the levels of serum aminotransferase (ALT) were closely matched and compared with those of the untreated control group (20 cases). Eighteen out of 20 patients received Ara-A, 19 patients received alpha-INF, and 19 out of 20 control cases were evaluated at 12 months after completion of treatment. Seroconversion of HBeAg in the alpha-INF treated group (19 cases) was observed in seven cases (36.8%), showing a higher seroconversion rate as compared to Ara-A-treated (2/18 cases, 11.1%) and to the control patients (1/19 cases, 5.3%). There were no effects of Ara-A on serum ALT levels in the treated patients compared with the untreated control patients. However there was a remarkable drop in serum ALT levels in the INF-treated patients (p less than 0.005, ALT levels at 12 months after treatment; 87.4 +/- 98.8 IU/L) compared to the pretreatment levels (256.7 +/- 175.8 IU/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Arterialization of the liver. II. Systemic pressure gradients in rats following variously sized arteriovenous fistulae

Four groups (I, II, III, and IV) of six Wistar rats each were studied to elucidate the blood pressure changes following creation of arteriovenous fistulae (AVF) of diameters 1, 2, and 3 mm (groups II, III, and IV, respectively). Group I comprised normal rats with no AVF. Blood pressures were recorded in the carotid and femoral arteries, the femoral and portal veins, the right atrium, and the inferior vena cava (IVC) at renal vein (RV) and common iliac vein (CIV) levels. We found that AVF size did not disturb baseline carotid arterial or portal venous pressures (P greater than 0.01), but the femoral arterial pressures fell increasingly (P less than 0.01). On the other hand, right atrial pressure and that of IVC at RV and CIV levels rose substantially with increasing diameters of AVF (P less than 0.01). It was concluded that an AVF of 1 mm diameter least upset the normal blood pressures in the vessels examined.

Keratinocyte damage produced by 12-O-tetradecanoylphorbol-13-acetate in rodent epidermis

Cell damage produced by 12-O-tetradecanoylphorbol-13-acetate (TPA) was evaluated in keratinocyte suspensions obtained from TPA treated mouse epidermis using a dye-exclusion technique, and in tissue sections studied by light microscopy and quantitative enzyme histochemistry. TPA induced a maximum of approximately 25% of trypan blue stained basal keratinocytes using topical doses of 2, 20 and 200 micrograms. With the first two doses this effect was detectable at 12-24 h and disappeared 48-96 h after TPA treatment, whereas with 200 micrograms TPA the cell damage persisted for a longer time. Oxidative enzyme changes were moderate, and no changes in acid phosphatase levels could be detected. The facts that no signs of cell necrosis could be seen in tissue sections from epidermis treated with 2 and 20 micrograms TPA; that only a moderate change in oxidative enzyme pattern, without statistically significant variations in succinic dehydrogenase and cytochrome oxidase, could be detected, and that no shift of the damaged basal keratinocytes into the suprabasal compartment was evident, are indicative of moderate, probably sublethal damage induced by TPA. Although eventually committed to terminal differentiation, the epidermal cells do not show the cytologic and metabolic features of lethally damaged cells, suggesting that the membrane damage detected by the dye exclusion technique may be sublethal. Thus, it is possible that TPA can induce a reactive or regenerative type of epidermal hyperplasia without the prerequisite of extensive keratinocyte necrosis.