Table of Content

31 August 1990, Volume 8 Issue 3

Previous Issue    Next Issue

DETECTION OF CIRCULATING ANTIGEN IN SCHISTOSOMIASIS BY DOT-ELISA WITH MONOCLONAL ANTIBODY

1990, 8(3):  161-164. 

Asbtract ( )   PDF (309KB) ( )  

Related Articles | Metrics

Circulaing antigen in sera from acute, chronic and late stages of schistosomiasis patients was detected by direct dot-ELISA with monoclonal antibody 3D8A against schisto-some gut-associated cathodic antigen linked with peroxidase, the positive rates being 90.6 %, 83.2% and 30.7%, respectively. No positive reactions were found with sera from patients of clonorchiasis, malaria and non-parasitic diseases. The positive rate and the circulating antigen level in EPG100 group of patients were found to be higher than those in EPG 100 group. Circulating antigen became negative one year after praziquantel treatment in 84.0% of patients who showed negative fecal examination, while the other patients remained positive with decreasing tilers. The results indicated that the circulating antigen in sera from schistosomiasis patients of various stages can be detected by dot-ELISA with monoclonal antibody 3D8A against circulating schistosome gut-associated cathodic antigen. The authors concluded that the circulating antigen level was correlated with the intensity of infection and the efficacy of treatment.

CONSTRUCTION OF A GENOMIC DNA LIBRARY OF TOXOPLASMA GONDII (ZS2 STRAIN), SCREENING OF SPECIFIC CLONE AND DNA DIAGNOSIS OF TOXOPLASMOSIS

1990, 8(3):  165-169. 

Asbtract ( )   PDF (1990KB) ( )  

Related Articles | Metrics

We have constracted a genomic DNA library of Toxoplasma gondii (ZS2 strain) and screened out a specific DNA sequence for T. gondii. The restriction map of the cloned DNA fragment (1.1kb) was analysed. The Southern and dot-blot analyses showed that the 32P-labeled cloned DNA fragment hybridized to the parasite DNA, DNAs from peripheral white blood cells and thymus of baby pigs artificially infected with T. gondii and DNAs of T. gondii- positive anencephalus and hydrocephalus, but did not hybridize to DNAs from controls, i. e., normal human and baby pig peripheral white blood cells, spleen of normal mouse, Plasmodium falciparum, Pneumocystis carinii and pBR322. As few as 100 T. gondii parasites or 500pg purified DNA from T. gondii can be detected by dot blot hybridization. This established DNA probe method was specific and sensitive and has been successfully used in detecting various cases infected with T. gondii.

EFFECT OF PRAZIQUANTEL TREATMENT ON THE LEVELS OF CIRCULATING SJ70 ANTIGEN IN MURINE SCHISTOSOMIASIS JAPONICA

1990, 8(3):  170-173. 

Asbtract ( )   PDF (316KB) ( )  

Related Articles | Metrics

A circulating schistosome 70kDa antigen (SJ 70) has been detected in sera of mice infected with Schistosoma japonteum. using a double antibody sandwich enzyme-linked immunoabsorbent assay (ELISA). SJ 70 antigen was first detected in the sera of S. ja-poreicum-infected mice at the 4th week after infection and increased rapidly, reaching their peak by the 7th week after infection, and remaining relatively unchanged for additional 9 weeks. In contrast, in mice infected with S. japonicum for 7 weeks and then treated with praziquantel (100mg/kg body weight) there was a significant decrease in serum antigen levels within two weeks after treatment. An almost complete disappearance of the antigen from the sera occurred by the 5th week after treatment.The results indicated that the detection of SJ 70 antigen might be used as early diagnosis of schistosoniasis and evaluation of drug efficacy

RESTRICTION FRAGMENT LENGTH DIFFERENCES (FFLDs) OF GENOMIC DNA FROM DIFFERENT GEOGRAPHICALSTRAINS OF ANOPHELES SINENSIS AND ANOPHELES ANTHROPOPHAGUS

1990, 8(3):  174-176. 

Asbtract ( )   PDF (686KB) ( )  

Related Articles | Metrics

Total DNA was extracted from three geographical strains of Anopheles sinensis and two geographical strains of Anopheles anthropophagus and digested respectively with three restriction endonucleases (Bgl Ⅱ, Hae Ⅲ and Pst Ⅰ). The restriction fragment length differences (RFLDs) of repetitive DNA detected after agarose gel electrophoretic separation and ethidium bromide staining were compared among the above-mentioned geographical strains of both An. sinensis and An. anthropohagus. The results indicated that the band patterns are species- specific and strain- specific, their main bands being similar while their minor bands being distinctly different. Pst Ⅰ digestion produced unique fragments for three geographipal strains of An. sinensis while Bgl Ⅱ digestion produced unique fragments for two geographical strains of An. anthropophagus. In view of the variation in repetitive DNA of different geographical strains of both An. sinensis and An. anthropophagus presented, the RFLDs could be used as a means to distinguish various closely related geographical strains of anopheline mosquitoes.

DETECTION OF CIRCULATING ANTIGEN AND/OR ANTIGEN-ANTIBODY COMPLEX BY USING McAb AGAINST SURFACE MEMBRANE ANTIGEN OF ADULT SCHISTOSOMA JAPONICUM

1990, 8(3):  177-180. 

Asbtract ( )   PDF (313KB) ( )  

Related Articles | Metrics

In the present paper, the results of detecting circulating antigen and/or antigen-anti-body complexes by McAb against surface membrane antigen of adult Schistosama japo-nicum were reported. The McAb, coded as 8SE4, was prepared by fusion of SP2/0 myeloma cslls with spleen cells of the BALB/c mice immunized with the saline extract of adult S, japonicum. The 8SE4- directed antigen was proved to be located on the surface of the adult worm. After being purified by a DE52 column, 8SE4 was labelled with HRP and the conjugate (HRP-8SE4) was used in the test. For testing, the serum sample was first incubated with HRP-8SE4, then PEG (mw. 6 000) was added to precipitate the antigen-antibody complex. Upon centrifugation, OPD was added to the precipitate. Results were read by ELISA reader at 492nm. The OD value was found to be proportional to the amount of circulating antigen and/or antigen-antibody complexes. Results from 5 heavily infected (1 500-2 000 cercariae) rabbits showed that the OD values were raised signifi-cantly at the 6th week post infection, being 1.9-4.5 times higher than those before ins faction. The OD values of the 5 rabbits each lightly injected with 10-500 cercariae were also markedly raised 6 weeks post infection and reached the peak at the 8th week, then maintained in high levels until 11th week post infection. The worm burden of the 5 lightly infected rabbits were 4-326. No obvious correlations between OD values and worm loads were observed. The results suggested the existence of surface membrane-related an-ligen and/or antigen-antibody complexes in the circulation of infected rabbits.

FREE AMINO ACID COMPONENTS OF CYSTIC FLUID OF CYSTICERCUS CELLVLOSAE

1990, 8(3):  181-184. 

Asbtract ( )   PDF (309KB) ( )  

Related Articles | Metrics

The free amino acids in the cystic fluid of Cysticercus cellulosae were determined quantitatively by using automatic amino acid analyzer. The cystic fluids of both subcutaneous-muscular Cysticercus cellulosae from 1.4 pigs and cerebral Cysticercus cellulosae from 10 pigs were detected. Among the 18 amino acids detected, alanine was found to be the predominant amino acid in both of the cystic fluids. The quantities of glycine and proline were higher than other amino acids in subcutaneous-muscular Cysticercus cellulosae, while threonine was higher than the rest in the cerebral Cysticercus cellulosae. A comparison was made between the quantities of amino acids in the fluids of both subcutaneous-muscular and cerebral Cysticercus cellulosae of 7 pigs by the T-test method. The results showed that the quantities of 12 out of 15 amino acids were significantly different, with particular reference to threonine, alanine, serine, and valine, suggesting that the difference in the metabolism of amino acids in Cysticercus may be related to the parasite's location in their respective hosts.

STUDIES ON CHROMOSOMES OF PERIODIC BRUGIA MALAYI

1990, 8(3):  185-186. 

Asbtract ( )   PDF (1091KB) ( )  

Related Articles | Metrics

A study was carried out on the chromosomes of periodic Brugia walayi usirg air drying preparations of testis, ovary and uterus. The results showed that the oogonial metaphase consisted of 4 pairs of small-sized autosomes and one pair of large-sized rex-chromosomes, that the spermatogonial metaphase consisted of 4 peirs of small-sized autcmes and one large-sized and one medium-sized sex-chromosome, the oocytes at diakinesis had 5 bivalents, the secondary spermatocytes 5 wnivalents and the fertilized eggs 10 chromosomes. The above-mentioned findings revealed that the chromosome number was 2n=10 and that the sex-determining mechanism was of the XY-XX type in this type of B. malayi.

TENTATIVE STUDY OF GEOGRAPHICAL EPIDEMIOLOGY OF SCHISTOSOMIASIS JAPONICA IN YUNNAN PROVINCE

1990, 8(3):  187-190. 

Asbtract ( )   PDF (290KB) ( )  

Related Articles | Metrics

Schistosomiasis prevails in 17 counties and cities in Yunnan Province.Approximately, a population of 301 511 were affected and the snail-ridden area amounted to 219 000 000m2 in the past years. These endemic areas were not evenly distributed, but rather scattered.The endemic foci were vertically distributed at an altitude of 1 350-2 450 metres above sea level. Human cases were found mostly in areas with an elevation of ≥1 800 metres, and became progressively fewer with the ascent. However, in areas with an-elevation of ≤1800 metres, the infection rate in the inhabitants decreased with the descent.In areas with an average temperature of 11.8-19.5℃ and the annual rainfall up to 574-970mm, transmission of the Schistosomiasis was always present, suggesting an annual mean temperature around 15.7℃ and rainfall 800-900mm were favourable factors for Schistosomiasis transmission.The cultivated areas with paddy soils were most suitable for the breeding of Oncome-lania snails, where Schistosomiasis was severely prevalent. Only a few Oncomelania snails and patients were observed in areas covered with red loam. No patient or snail was found in areas with brown loam or mountain meadow soil.

ON THE TRANSMISSION ROLE OF RESIDUAL MICROFILAREMIA CASES IN THE AREA WITH FILARIASIS VIRTUALLY ERADICATED

1990, 8(3):  191-194. 

Asbtract ( )   PDF (299KB) ( )  

Related Articles | Metrics

The transmission role of the residual microfilaremia cases was studied in Pingle Village, Liangqing Township, Yongning County where bancroftian filariasis had been virtually eradicated during 1984-1988. The results indicated that after the microfilarial rate of the human population met the criterion of elimination of f ilariasis, namely below 1% of the total population in all the administrative villages, and the average density of microfilana being around 5 per 60μl peripheral blood, subsequent control measures might be no Ion- ger instituted while the microfilaria rate and its density could continue to decline. Some residual microfilaremiae cases having higher microfilarial density turned negative gradually, so did the natural infection rate of Culex quinquefasciatus with filaria larvae and its density year by year. No filaria larvae were found in vector mosquitoes in 1987-1988. The authors deemed that the filariasis transmission in this area has been interrupted.

QUANTITATIVE STUDY ON INFESTATION AND DISTRIBUTION OF HUMAN DEMODEX ON THE FACE

1990, 8(3):  195-198. 

Asbtract ( )   PDF (1269KB) ( )  

Related Articles | Metrics

We have tried to use 1.2cm × 5cm (6cm2) adhesive cellophane tape technique for quantitative detection of Demodex. 618 mites were detected on the 24 tapes applied on various parts of the face of a healthy individual.In an investigation of 8 person-times, the numbers of mites found on various parts of the face were in the following order: upper-cheek(233), mid-cheek(153), lower-cheek (114), chin(78), forehead(59.5), nose(55), infraorbital(54.5), paraoral(49.5), nasal groove(45), mites found on other parts being negligible.Demodex brevis were found scattering singly on the tapes, while D. follicutorum were found 1-6 in number in one or several follicles. All of them were in the follicle opening, indicating that transmission was readily affected through direct or indirect contacts.The results also showed that when a large number of mites were sticked off, the intensity of infestation was decreased.

SUCCESSFUL AXEINIC CULTIVATION OF A LOCAL HUMAN STRAIN OF GIARDIA LAMBLIA IN SUCKLING GERBIL

1990, 8(3):  199-202. 

Asbtract ( )   PDF (308KB) ( )  

Related Articles | Metrics

G. lambtia cysts isolated from the fresh feces of a Gtardia-infected boy in Beijing rural area were inoculated into suckling gerbils (Meriones unguiculatus). Trophozoites of G. lamblia obtained from the intestines of infected gerbils were cultivated in modified TYI-S-33 medium enriched with dehydrated bovine bile. The parasites grew luxuriantly and formed an intensive monolayer on the surface of the culture tube on day 14 after initial cultivation. The culture has been maintained for more than 12 months and more than 120 subcultures have been made. The growth curve of the organism showed that the peak growth of the trophozoites was attained at the 120th hour after seeding The generation time was 15±2.0 hours. Periodic examinations of Giardia cultures for bacteria contamination, with Petri dishes of blood agar and beef broth, proved negative. After being cryopreserved in liquid nitrogen for 1 week or longer, the average viable rate of the organism was 65.7% and the resuscitated parasites grew luxuriantly in subcultures.

STUDIES ON THE EFFICACY OF FIVE REPELLENTS AGAINST PHLEBOTOMUS ALEXANDRI

1990, 8(3):  203-206. 

Asbtract ( )   PDF (292KB) ( )  

Related Articles | Metrics

The efficacy of five repellents were tested against Phlebotomus alexandri both in the laboratory and in the field in Meiyaogou, Turfan City, Xinjiang Uygur Autonomous Region during 1986-1987. A total of 3 301 female Ph. alexandri were used in the laboratory and 306 man-times of volunteers were tested in the field. At a dose of 0.25 μl/cm2, the protective durations of mosquito repellent perfume (MRP), N, N-diethyl-m-taluamide (DETA), mosquito repellent liquid (MRL), dimethyl phthalate (DMP) and di-butyl phthalate (DBP) were 7.50h, 5.00h, 3.75h, 1.25h and 1.00h, respectively. At a dose of 0.75mg/cm2, the protective durations of the essential balms of DETA.DMP and DBP were 5.50h, 3.50h and 3.00h, respectively. The repelling effect on volunteers in the field was the same as that tested in the laboratory. The relative efficacy of the five repellents was in the order of MRPDETAMRLDMPDBP.The above-mentioned repellents may be of practical use for individual protection against kala-azar transmission in the field.

DOT-ELISA IN THE DIAGNOSIS OF NEUROCYSTICERCOSIS

1990, 8(3):  207-209. 

Asbtract ( )   PDF (210KB) ( )  

Related Articles | Metrics

The doteRzyme-linked immunosorbent assa was used to detect Cysticercus cellulosae antibodies in sera of patients with neurocysticercosis. Among 108 confirmed cases of neurocysticercosis 81.6-96.1% showed positive reactions. Two out of 54 normal control sera reacted at a serum dilution of 1:20, but none at a 1:40 (range 40-640). No cross reactions were observed with sera from cases of paragonimiasis and clonorchiasis, but it did occur to some extent with sera from cases of echinococcosis and cerebrovascular diseases. The results indicated that the dot-ELISA was sensitive, specific and economic for the diagnosis of neurocysticercosis.

STUDIES ON DYNAMICS OF ANTIBODIES IN SERA FROM RABBITS IMMUNIZED WITH HOMOLOGOUS AND HETEROLOGOUS ADULT FILARIAL ANTIGENS

1990, 8(3):  210-213. 

Asbtract ( )   PDF (290KB) ( )  

Related Articles | Metrics

The indirect immunoflouresent antibody test (IFAT) and immunoenzymatic staining technique (IEST) with frozen sections of Brugia malayi and Setaria cervi adult worms as antigens were used to detect IgG levels in rabbits immunized with three different filarial antigens. The results showed the dynamics of the specific IgG antibody in the course of immunization. The peaks (GMRT 76.11-861.08) of feG levels in immunized rabbits appeared at the 4th week after primary immunization, which returned to (4.00-32.0 up to the 8th week after paimary immunization and rose to(20.11-181.02)at the 1st week after second immunization. It is suggested that IF AT and IEST, especially the latter, can be applied for serodiagnosis of filarial infection and both antigens are considered to be of similar diagnostic effect.

INTESTINAL MYIASIS IN MACAO

1990, 8(3):  214-216. 

Asbtract ( )   PDF (416KB) ( )  

Related Articles | Metrics

Six cases of intestinal myiasis were diagnosed in Macao from January 1987 to August 1989, during a survey of intestinal parasites in inhabitants and on stool routine examination in hospitalized patients. The species of flies identified were Stomoxys calcitrans in 4 cases and Megaselia (Megalesia) insulana in 2 cases, M. insulana being a new record in mainland of China.During the survey of intestinal parasites 1889 human fecal samples were collected from Chinese inhabitants. 45 samples were collected on September 2 and 15 samples on September 11, 1987 in an aged home. Among them 4 samples were found to have some moving larvae, which were later identified morphologically as S. calcitrans. All these four cases were old ladies living in the aged home and they complained of mild diarrhea and abdominal pain.The fifth case was a patient with dermatosis, who had an eosinophhil count of 18%. On stool examination, eggs of Clonorchis sinensis and larvae of flies were found. These larvae were cultured in food stuff containing wheat bran (100g), milk powder (18g) and water (200ml) at 30℃. Within a week these larvae became pupa from which hatched adult flies identified as M. insulana which were known to be distributed in the Philippines and Hawaii but not found in the mainland of China before. 3 months later the stool from the patient was re-examihed, about 200 larvae were counted in 5 ml of feces, the fly species being he same.The sixth patient was a pediatric case, again in his stool sample larvae of flies were found which were identified as M. insulana after culture.M. insulana is distributed in the Philippines, Hawaii, etc. Since a great amount of fruits was constantly imported from the Philippines and Hawaii, it remains to be confirmed whether M. insulana is imported into Macao through fruits.

CLINICAL MANIFESTATION AND TREATMENT OF PULMONARY ACARIASIS

1990, 8(3):  217-219. 

Asbtract ( )   PDF (234KB) ( )  

Related Articles | Metrics

A survey on pulmonary acariasis was carried out in the grain store and in the Chinese medicinal herb plant. Of 363 persons examined, 92(25.3%) were mites-positive in their sputum. 65 of them had symptoms and signs attributed to pulmonary acariasis, the incidence being 17.9%. The main clinical manifestations were productive cough, hemoptysis, chest pain, dyspnea asthma and marked eosinophilia. Roentgenogram of these cases revealed widening hilum shadow, increased and disordered lung markings, multiple cloudy shadow and nodular opacities ranging from 1-5mm in diameter scattered throughout the lower field of lungs.All the patients were treated with three courses of metronidazole. In each course a daily dose of 0.6g (0.2g tid) or 0.8g (0.4g bid) was given orally for seven days with an interval of 7-10 days between two courses. After three courses, the clinical manifestations and radiographic findings were much improved in most cases, eosinophilia, dropped to normal limit, mites disappeared from sputum in 94.4% of patients. All these showed that metronidazole is rather effective in treating pulmonary acariasis;