Sequence analysis of leader and trailer regions of rice yellow stunt rhabdovirus and characterization of their in vivo transcripts

The 3' leader and the 5' trailer of the rice yellow stunt rhabdovirus (RYSV) genomic RNA have been cloned and sequenced. Sequence data indicate that the RYSV leader region is composed of 203 nucleotides (nt) and the trailer region 191 nt. The terminal 9 nt of the two regions are complementary and capable of forming a putative panhandle structure common to rhabdovirus genomes. In comparison with the leader or trailer sequences of other rhabdoviruses reported so far, both the leader and trailer of RYSV are the longest and there is no obvious sequence homology between the counterparts except for a few terminal nt and the UGUU motif in the leader sequences. Polyadenylated plus-strand leader RNA has been detected in RYSV-infected rice plants by 3' RACE. This is the second example in rhabdoviruses following the report for sonchus yellow net virus (SYNV) for existence of a polyadenylated leader RNA. No polyadenylated plus-strand transcripts of the RYSV trailer have been found using the similar method.

Recombination with coat protein transgene in a complementation system based onCucumber mosaic virus (CMV)

In order to study the feasibility ofCucumber mosaic virus (CMV) as an expression vector, the full-length cDNA of RNA 3 from strain SD was cloned and the sequence around the start codon of the coat protein (CP) gene was modified to create anNsi I site for insertion of foreign genes. The CP gene was replaced by the green fluorescent protein (GFP) gene. The cDNAs of Fny RNAs 1 and 2 and the chimeric SD RNA 3 were cloned between the modified 35S promoter and terminator. Tobacco protoplasts were transfected with a mixture of the viral cDNAs containing 35S promoter and terminator as a replacement vector and expressed GFP. A complementation system was established when the replacement vector was inoculated onto the transgenic tobacco plants expressing SD-CMV CP. GFP was detected in the inoculated leaves in 5 of 18 tested plants and in the first upper systemic leaf of one of the 5 plants ten days after inoculation. However, no GFP could be detected in all the plants one month after inoculation. Recombination between the CMV vector and the CP transgene was proved by retro-transcriptional polymerase chain reaction (RT-PCR) and verified by DNA sequencing. Our results argue against the feasibility of the CMV-based replacement vector trans-complemented by the CP transgene, and at the same time, enlighten ways to improve the CMV-based expression vector and the biosafety of CMV CP-mediated virus resistant transgenic plants.

Mixed-effects statistical model for comparative LC-MS proteomics studies

Comparing a protein's concentrations across two or more treatments is the focus of many proteomics studies. A frequent source of measurements for these comparisons is a mass spectrometry (MS) analysis of a protein's peptide ions separated by liquid chromatography (LC) following its enzymatic digestion. Alas, LC-MS identification and quantification of equimolar peptides can vary significantly due to their unequal digestion, separation, and ionization. This unequal measurability of peptides, the largest source of LC-MS nuisance variation, stymies confident comparison of a protein's concentration across treatments. Our objective is to introduce a mixed-effects statistical model for comparative LC-MS proteomics studies. We describe LC-MS peptide abundance with a linear model featuring pivotal terms that account for unequal peptide LC-MS measurability. We advance fitting this model to an often incomplete LC-MS data set with REstricted Maximum Likelihood (REML) estimation, producing estimates of model goodness-of-fit, treatment effects, standard errors, confidence intervals, and protein relative concentrations. We illustrate the model with an experiment featuring a known dilution series of a filamentous ascomycete fungus Trichoderma reesei protein mixture. For 781 of the 1546 T. reesei proteins with sufficient data coverage, the fitted mixed-effects models capably described the LC-MS measurements. The LC-MS measurability terms effectively accounted for this major source of uncertainty. Ninety percent of the relative concentration estimates were within 0.5-fold of the true relative concentrations. Akin to the common ratio method, this model also produced biased estimates, albeit less biased. Bias decreased significantly, both absolutely and relative to the ratio method, as the number of observed peptides per protein increased. Mixed-effects statistical modeling offers a flexible, well-established methodology for comparative proteomics studies integrating common experimental designs with LC-MS sample processing plans. It favorably accounts for the unequal LC-MS measurability of peptides and produces informative quantitative comparisons of a protein's concentration across treatments with objective measures of uncertainties.

Evaluation of the Genplex SNP typing system and a 49plex forensic marker panel

Using a 52 SNP marker set previously developed for forensic analysis, a novel 49plex assay has been developed based on the Genplex typing system, a modification of SNPlex chemistry (both Applied Biosystems) using oligo-ligation of pre-amplified DNA and dye-labeled, mobility modified detection probes. This gives highly predictable electrophoretic mobility of the allelic products generated from the assay to allow detection with standard capillary electrophoresis analyzers. The loci chosen comprise the 48 most informative autosomal SNPs from the SNPforID core discrimination set supplemented with the amelogenin gender marker. These SNPs are evenly distributed across all 22 autosomes, exhibit balanced polymorphisms in three major population groups and have been previously shown to be effective markers for forensic analysis. We tested the accuracy and reproducibility of the Genplex system in three SNPforID laboratories, each using a different Applied Biosystems Genetic Analyzer. Genotyping concordance was measured using replicates of 44 standardized DNA controls and by comparing genotypes for the same samples generated by the TaqMan, SNaPshot and Sequenom iPLEX SNP typing systems. The degree of informativeness of the 48 SNPs for forensic analysis was measured using previously estimated allele frequencies to derive the cumulative match probability and in paternity analysis using 24 trios previously typed with 18 STRs together with three CEPH families with extensive sibships typed with the 15 STRs in the Identifiler kit.

In vitrocytotoxicity activity on several cancer cell lines of acridone alkaloids andN-phenylethyl-benzamide derivatives fromSwinglea glutinosa(Bl.) Merr

The methanol extract from the stems and fruits of Swinglea glutinosa (Rutaceae) afforded 11 known acridone alkaloids and three N-phenylethyl-benzamide derivatives, glycocitrine-IV, 1,3,5-trihydroxy-4-methoxy-10-methyl-2,8-bis(3-methylbut-2-enyl)acridin-9(10H)-one, 1,3,5- trihydroxy-2,8-bis(3-methylbut-2-enyl)-10-methyl-9-acridone, citbrasine, citrusinine-II, citrusinine-I, 5-dihydroxyacronycine, pyranofoline, 3,4-dihydro-3,5,8-trihydroxy-6-methoxy-2,2,7-trimethyl-2H-pyrano[2,3-a]acridin-12(7H)-one, 2,3-dihydro-4,9-dihydroxy-2-(2-hydroxy-propan-2-yl)-11-methoxy-10-methylfuro[3,2-b]acridin-5(10H)-one, bis-5-hydroxyacronycine, N-(2-{4-[(3,7-dimethylocta-2,6-dien-1-yl)oxy]phenyl}ethyl)benzamide, N-(2-{4-[(3,7-dimethyl-4-acethyl-octa-2,6-dien-1-yl)oxy]phenyl}ethyl)benzamide, and severine acetate. All compounds isolated were examined for their activity against three cancer cell lines: human lung carcinoma (COR-L23), human breast adenocarcinoma (MCF7), human melanoma (C32), and normal human fetal lung cell line, MRC-5. The acridones tested exhibited weak cytotoxicity but the amides showed moderate nonselective cytotoxic activity.

Detection of R. felis and R. typhi in fleas using monoclonal antibodies

Rickettsia typhi and R. felis are flea-transmitted human pathogenic rickettsial species. To investigate the distributional dynamics of these rickettsiae we designed a micro-immunofluorescence assay (MIF) using species-specific monoclonal antibodies (MAbs) applied to flea cryosections. Our assay was performed in less than 3 h and its applicability was demonstrated by the detection of R. typhi in 50 artificially infected human body lice but in none of 50 uninfected lice. With MIF, we identified 31 positive among 32 fleas proven with PCR to be naturally infected with R. felis; and 7 positive among 32 fleas proven with PCR to be naturally infected with R. typhi. No cross-detection was observed with both MAbs. Fresh R. felis-infected fleas were significantly more MIF-positive than long conserved R. typhi-infected fleas (31/32 vs. 7/32, P < 0.01). This discrepancy may be linked to degradation of antigens by long-term freezing. For R. typhi-infected fleas, our assay was significantly more efficient when applied to fleas in early stages of infection (less than 15 days) by comparison with fleas frozen more than 20 days after infection (7/15 vs. 0/17, P = 0.01). This difference may be related to an antigenic modification caused by selection pressure in the vector and host process. The sensitivity of the described method did not exceed 47% (7/15) for R. typhi but, in contrast, was 97% for R. felis. Thus, our method appears to be useful for surveillance in R. felis infections, but requires further studies for the detection of R. typhi.

[Application of immunochromatographic test for diagnosis and surveillance of bancroftian filariasis]

AIM

To evaluate the usefulness of immunochromatographic test (ICT) for rapid diagnosis and surveillance of Wuchereria bancrofti infection.

METHODS

The monoclonal antibody based-ICT assay was used to detect filarial antigens in the sera from bancroftian filariasis patients.

RESULTS

111 out of 116 bancroftian microfilaria cases showed positive ICT reaction, giving a positive rate of 95.7%. Serum samples from 12 malayian microfilaremia cases, 33 ascariasis cases, 20 schistosomiasis japonica cases and 6 trichinellosis cases were all found negative in ICT, demonstrating a specificity of 100%. In 73 chronic filariasis cases with elephantiasis, hydrocoele, and chyluria cases, 18 showed ICT positive, among whom 16 revealed microfilaremia, suggesting that the ICT positive cases were with active infections. Of the 30 microfilaremia cases before single dose ivermectin treatment, 29 were ICT positive (96.7%). A negative conversion of microfilaremia was observed in all cases 8-14 days post-treatment. Upon following up to 6 and 12 months, microfilaremia reappeared in 5 and 7 cases, respectively. 5 out of 13 ICT positive cases were found microfilaremic at 6 month post-treatment, while among the rest of 8, 5 were found microfilaremic at 12 month post-treatment. Parallel use of ICT with routine blood film examination in Houda village, Zhecheng County, Henan Province for a post-control surveillance survey in 132 local individuals revealed 9 microfilaremia cases were also ICT positive. Of the 123 persons with negative blood examination, only 1 was ICT positive.

CONCLUSION

ICT is a rapid and simple method with high sensitivity and specificity, and might be used for the diagnosis, efficacy evaluation as well as a tool for post-control surveillance of bancroftian filarasis.

[Discovery of natural variant strain of HIV1 in env gene C2-V3 encoded PND of membrane protein]

OBJECTIVE

To sequence and analyze the env gene C2-V3 region of proviral genome from a HIV1 isolate(WWBH7) which was obtained from Huadong Area in China.

METHODS

The env gene C2-V3 DNA fragment was amplified by nested-primer PCR with genome DNA of eripheral blood mononuclear cells from a confirmed HIV1 infected individual as a template. The amplified DNA fragment was inserted into pGEM-T vector. The recombinant plasmid was confirmed by restriction enzyme analysis. The inserted DNA fragment was sequenced by ABI737 autosequencer and analyzed by PROSIS software.

RESULTS

The HIV1 strain was the derivatives of HIV1 B subtype. But there was mutation of 192 bp fragment repeated insertion at env C2-V3 region of the HIV1 strain compared with standard HIV1 B subtype such as SF2 strain. The mutation brought about a double V3 region in gene encoded PND (principal neutralizing domains). The DNA sequence was registered in GenBank (AF220245).

CONCLUSIONS

This was a natural mutated variant strain of HIV1 whose genome showed a 192 bp repeated insertion at C2-V3 region of env gene encoded PND of membrane protein.

A sensitive and rapid method for the determination of protein by the resonance Rayleigh light-scattering technique with Pyrogallol Red

The resonance Rayleigh light-scattering (RRLS) technique was used to develop a simple, sensitive and selective method for the determination of proteins. The method is based on the interaction between proteins and Pyrogallol Red (PR) in the pH range 3.6-4.2, which causes a substantial enhancement of the resonance scattering signal of PR in the wavelength range 300-450 nm with the maximum scattering peak located at 347 nm. With this method, 0.25-13 microg ml(-1) of bovine serum albumin (BSA), 0.25-10 microg ml(-1) of human serum albumin (HSA) and 0.25-13 microg ml(-1) of human immunoglobulin G (IgG) can be determined, and the detection limits, calculated as three times the standard deviation of nine blank measurements, for BSA, HAS and IgG were 51, 48 and 57 microg l(-1), respectively. Moreover, the method shows almost no protein-to-protein variability and is free from interference from many amino acids and metal ions. The method, with high sensitivity, selectivity and reproducibility, was satisfactorily applied to the determination of the total protein in human serum and saliva samples. Mechanism studies indicated that PR can bind to BSA depending mainly on electrostatic forces, and this interaction can encourage the J-aggregation of PR, which results in enhanced Rayleigh light-scattering in the PR-protein system.

Effects of DL111-IT or combined with RU486 on uterine polyamines biosynthesis in rats during early gestation

DL111-IT, a non-hormonal contragestional agent, revealed synergistic effects in combination with mifepristone (RU486) in some species. The present study was undertaken to clarify the role of DL111-IT when used alone or plus RU486 on uterine polyamines biosynthesis, histologic alteration of decidual cells, and antifertility activity in rats. The levels of polyamines in pregnant rat uterus were determined by formed benzoyl chloride derivatives of polyamines for RP-HPLC. The results showed that all the treated groups including DL111-IT 2.8 mg. kg(-1). d(-1), RU486 3.0 mg. kg(-1). d(-1), and DL111-IT 0.56 mg. kg(-1). d(-1) plus RU486 0.6 mg. kg(-1). d(-1) caused 100% early pregnancy arrest. Uterine putrescine, spermidine, and spermine levels in comparison with vehicle control were declined significantly from d7 of gestation (1 day after treatment) to d9 or d14 (3 days or 8 days after treatment) by Duncan's multiple range test, and accompanied by histologic alterations, edema, degeneration and dissolution of decidual cells with nuclei indefinite in appearance on d8 of gestation (2 days after treatment). The combined administration at lower doses caused the most injury. The data verified that the decrease in uterine polyamine levels and subsequent decidual cells injuries were the critical role of early pregnancy arrest induced by DL111-IT or RU486. The two compounds used in combination with lower dosages revealed greatly synergistic effects.

Cohort cancer incidence among pulp and paper mill workers in British Columbia

OBJECTIVES

A study was conducted to investigate cancer risks in a cohort of pulp and paper workers.

METHODS

All male workers with > or =1 years of employment in 14 pulp and paper mills in 1950-1992 were studied. Standardized incidence ratios (SIR) were used to compare the cancer incidence of the cohort with that of the Canadian male population. Record linkage with the National Cancer Registry was performed using the generalized iterative record linkage method.

RESULTS

Altogether 1756 cancer cases were observed in the entire cohort. For > or =15 years of work, the entire cohort had significantly increased SIR values for pleural and prostate cancer and skin melanoma; there was also a significantly increased risk for skin melanoma among workers in the kraft process only, rectal cancer among workers in the sulfite process only, and stomach and prostate cancer and all leukemias combined among workers in both the kraft and sulfite processes. A separate analysis comparing workers in pulping and papermaking with those in the pulping process only did not reveal any difference in cancer risk and hence did not modify the results. The SIR values for skin melanoma were not significantly increased in a comparison using the British Columbia male population. Nine of 10 pleural cancers were mesotheliomas, which likely reflect past asbestos exposure.

CONCLUSIONS

The results suggest that long-term work in the pulp and paper industry is associated with excess risks of prostate and stomach cancers and all leukemias for work in both kraft and sulfite processes and of rectal cancer for work in the sulfite process only.

The role of growth hormone in adaptation to massive small intestinal resection in rats

The residual small bowel undergoes profound adaptive alterations after surgical resection. GH is considered to have a role in regulation of these adaptive changes, but its precise role is unknown. We investigated the role of GH by studying the response to intestinal resection in rats with isolated GH deficiency. Spontaneous dwarf rats, a strain of rats with congenital isolated GH deficiency, underwent 60% resection of the small intestine and parameters of the response of the intestinal remnant were compared with age-matched GH-deficient rats undergoing transection, GH-normal rats undergoing 60% resection, and nonmanipulated GH-normal rats. Deficiency of GH did not inhibit hyperplasia of the mucosal mass of the intestinal remnant, indicating that GH is not required for regulation of this aspect of the adaptive response. However, GH deficiency resulted in lack of accumulation of mucosal protein, including lack of accumulation of digestive hydrolases. In addition, GH deficiency resulted in alterations in processing of digestive hydrolases of the distal intestine, indicating that GH may have region-specific effects on small intestinal function. We conclude that GH is required for the normal expression of specific components of the adaptive response to massive small intestinal resection, but not for all aspects. The aspects that require GH appear to involve protein synthesis and processing.

Thyroid hormone and the d-type cyclins interact in regulating enterocyte gene transcription

Thyroid hormone (T3) is an important regulator of gut mucosal development and differentiation, inducing intestinal alkaline phosphatase (IAP) and repressing lactase gene transcription. In contrast, cyclin D1 (CD1) appears to be a growth promoter in the gut, functioning to maintain the undifferentiated state. The present studies were designed to examine the effects of CD1 on T3 action within intestinal epithelia. Caco-2 cells were maintained in hypothyroid medium and transiently transfected with either rat lactase (3.0 kb) or human IAP (2.4 kb) luciferase (Luc) reporter plasmids. Cotransfections were carried out using two T3 receptor (TR) isoforms, TR"-1 and TR$-1, as well as plasmids expressing CD1, CD3, CA, or CB1. Cells were then treated +/- 10 nmol/L T3 for 24 hours and luciferase activity was determined. With T3 treatment, IAP-Luc activity was induced (TR"-1 = eightfold, TR$-1 = ninefold), but these effects were dramatically inhibited (> 50%) by CD1 and CD3. In contrast, CA and CB1 did not alter T3-mediated IAP gene activation. The ability of CD1 and CD3 to inhibit T3 action was also tested in the context of the lactase gene, which is negatively regulated by T3. As expected, lactase reporter gene activity was repressed by T3 treatment in the case of both receptor isoforms, TR"-1 = 30% and TR$-1 = 40%. In contrast to its effects on the IAP gene, CD1 did not inhibit T3-mediated changes in lactase reporter gene activity. The D-type cyclins (CD1 and CD3), but not CA or CB1, specifically inhibit T3-mediated activation of the IAP gene. In contrast, the D-type cyclins do not inhibit T3-mediated repression of the lactase gene. These studies have identified a novel molecular interaction that exists between the pathways of growth and differentiation within intestinal epithelia.

GATA family transcription factors activate lactase gene promoter in intestinal Caco-2 cells

The GATA family of transcription factors regulate tissue-specific patterns of gene expression during development. We have characterized the interaction between GATA proteins and the lactase gene promoter. Nuclear protein bound to the lactase gene GATA region cis element (-97 to -73) was analyzed by electrophoretic mobility shift assays (EMSA) and supershift assays with GATA antibodies. Lactase promoter activities were assayed in Caco-2 cells transfected with wild-type and mutated luciferase promoter-reporter constructs and GATA-4/5/6 expression constructs. EMSA with the GATA region probe yields a specific DNA-protein complex that requires the GATA factor binding site WGATAR. The complex is recognized by GATA-4- and GATA-6-specific antibodies. GATA-4/5/6 expression constructs are able to activate transcription driven by the wild-type promoter, but not by a promoter in which the GATA binding site is mutated, in Caco-2 and nonintestinal QT6 cells. GATA factor binding to the lactase cis element correlates with functional promoter activation. We conclude that each of the GATA family zinc finger proteins expressed in the intestine, GATA-4, -5, and -6, can interact with the lactase promoter GATA element and can function to activate the promoter in Caco-2 cells.

Identification of occupational cancer risks in British Columbia. A population-based case-control study of 995 incident breast cancer cases by menopausal status, controlling for confounding factors

Lifetime occupational histories as well as information on known and suspected breast cancer risk factors were collected by means of a self-administered questionnaire from 1018 women with incident breast cancer ascertained from the British Columbia Cancer Registry, and from 1020 population controls. A matched case-control study design was used. Conditional logistic regression for matched sets data and the likelihood ratio were used in a two-step procedure and were performed separately for pre-menopausal women, post-menopausal women, and for all cases combined. Excess risk was noted for several white-collar occupations. Significantly increased risk was observed: (1) among pre-menopausal women: in electronic data-processing operators; barbers and hairdressers; in sales and material processing occupations; and in the food, clothing, chemical and transportation industries; (2) among post-menopausal women: in schoolteaching; in medicine, health, and nursing occupations; in laundry and dry-cleaning occupations; and in the aircraft and automotive, including gasoline service station, industries. Several significant associations were also seen in the combined group of pre- and post-menopausal women, particularly in crop farmers and in the fruit and vegetable, publishing and printing, and motor vehicle repair industries. The results of this study suggest excess breast cancer risk in a number of occupations and industries, notably those that entail exposure to solvents and pesticides.

The homeodomain protein Cdx2 regulates lactase gene promoter activity during enterocyte differentiation

BACKGROUND & AIMS

Lactase is the intestinal disaccharidase responsible for digestion of lactose, the predominant carbohydrate in milk. Transcription of the lactase gene is activated during enterocyte differentiation. We have characterized the interaction between the lactase promoter and Cdx2, a homeodomain protein involved in regulating intestinal development and differentiation.

METHODS

Nuclear protein bound to the lactase gene cis element, CE-LPH1, was analyzed by electrophoretic mobility shift assays and supershifts with Cdx2 antibody. Lactase promoter activities were assayed in cells transfected with luciferase reporter constructs and a Cdx2 expression construct.

RESULTS

Electrophoretic mobility shift assay with CE-LPH1 yields a specific DNA/protein complex that requires the caudal-related protein binding site, TTTAC. The complex is recognized by Cdx2 antibody and is more abundant in differentiated enterocytes. A Cdx2 expression construct is able to activate transcription driven by the wild-type, but not a mutated, promoter and results in increased endogenous lactase messenger RNA.

CONCLUSIONS

The homeodomain protein Cdx2 interacts with the lactase promoter and is capable of activating transcription of the endogenous gene. In contrast to a previous report, Cdx2 interaction with the lactase promoter correlates with enterocyte differentiation. These conclusions are consistent with the role of Cdx2 in regulating intestinal cell differentiation.

Accuracy of surgeon-performed gallbladder ultrasound

BACKGROUND

Symptomatic cholelithiasis is among the most common of general surgery referrals. With an appropriate clinical presentation, definitive diagnosis requires documentation of gallstones by ultrasonography (US). The authors evaluated the accuracy of surgeon-performed US for identifying gallstones in patients with a nonacute indication for study.

METHODS

Patients referred for symptomatic cholelithiasis and who provided informed consent received an US examination by one or more of the surgical investigators. Surgeon-performed US findings were correlated with radiologist US findings and pathologic diagnoses.

RESULTS

Seventy-seven patients received a total of 128 examinations by the investigators. Surgeon-performed US examination agreed with the radiologist US findings for 112 of 122 studies (92%) with a sensitivity of 100% and a specificity of 95%. Surgeon-performed US findings correlated with the pathologic diagnoses for 83 of 86 studies (97%).

CONCLUSIONS

Surgeons can perform gallbladder US in the nonacute setting with a high degree of accuracy.

[Epidemiological survey on orchard pollinosis]

OBJECTIVE

To investigate the prevalence of Orchard Pollinosis in China.

METHOD

From 1995 to 1998, an epidemiological survey on orchard pollinosis was carried on among 1,660 primary and middle school students and 2,167 university students, including questionnaire investigation, nasal inspection and scratch test. From April to June of 1998, a clinical investigation of orchard pollinosis was adopted among 30 patients of allergic rhinitis including scratch test and nasal mucosa test.

RESULT

1. The total positive rate of orchard pollen scratch test was 6.7%, and the prevalence of orchard pollinosis was 0.37%. 2. 5 cases (16.7%) were hypersensitive to orchard pollen clinically in allergen test.

CONCLUSION

Orchard pollinosis is one kind of important pollinosis and should be paid high attention to.

[Evaluation of DNA recombinant chitinase fusion protein antigens in serological diagnosis for filariasis]

OBJECTIVE

To evaluate DNA-recombinant chitinase fusion protein antigen in serodiagnosis for Bancroft's filariasis in jirds rats with microfilaremia and normal jirds rats with ELISA, and its prospect in the market to be spread.

METHODS

Oligonucleotide was synthesized with filaria monoclonal antibody (Mf(1))-recognized microfilaria chitinase fusion protein and basic primer recognized by original clonal nucleosides, and amplified with polymerase chain reaction (PCR). PCR products were expressed in Pmal-c vector and purified by affinity chromatography. Experimental animals were inoculated with chitinase fusion protein antigen and infected with larval stage filaria Brugia malayi, respectively. Functional protein molecule of chitinase antigen was analyzed with SDS-PAGE and western blot. Serum level of specific antibody to chitinase antigen was determined by ELISA, and compared with that to microfilaria xt antigen (Mf-xt).

RESULTS

Specific function protein molecule of the above-mentioned chitinase antigen has been identified as 69,000. Serum antibody against chitinase antigen was 100% positive for jirds and patients with microfilaremia, but, that against Mf-xt only 80% positive. Serum antibody against chitinase antigen was negative for all normal jirds and normal persons, but that against Mf-xt had 5% false positive in normal serum. For those with microfilaremia from non-filariasis-prevalent areas, false sero-positivity was 5% and 20% with chitinase antigen and Mf-xt, respectively.

CONCLUSION

ELISA with DNA recombinant fusion protein antigen is a sensitive and specific method in serological diagnosis and surveillance for filariasis, with simple, easy and convenient manipulation. It can be used in field serologic surveillance and diagnosis for filariasis during the late phase in control of filariasis and can be spread in good prospects.

[The study of carbonaceous adsorbent for solid-phase microextraction and the comparison with commercial device]

The parameters governing solid-phase microextraction have been investigated, and the development of carbonaceous adsorbent for SPME is presented because it is durable and inexpensive. The time profile curves were determined for several organic pesticides having a wide range of water solubilities and the effect of salt was also investigated. The method of SPME-GC-ECD to analyse trace level of the organic pesticide in water is established by the determination of optimum parameters. The comparison with commercial SPME device shows that the carbonaceous adsorbent having been treated with physical or chemical method for SPME can get lower limits of detection than polyacrylate and polydimethylsiloxane, although there are still some work to be done to improve its precision. The results shows that this new SPME device has great application potential.

Supercritical fluid CO2 extraction of colchicine from colchicine Autumnele liliaceae

Colchicine was successfully extracted from the corms of colchicine autumnele Liliaceae using supercritical fluid (SF) CO2. The pressure range used in the experiments was 20-40 MPa and the temperature was 40 degrees C. Being its high molecular polar, colchicine or other alkaloids are not easy to be extracted by SF CO2. In order to increase the mass transfer from the sample matrix to SF, different presoakers (such as methanol, ethanol, acetone etc.) were employed. Among the selected pre-soakers, best results were obtained with ethanol both in the aspects of yield and selectivity. At 35 MPa, 40 degrees C and with ethanol as pre-soaker, the yield was 1.8 mg/g, and the colchicine could be almost completely extracted from the sample matrix. The average concentration increased from 0.18% in natural sample to 6.92% in extract with SFE processing only once under the given conditions. The comparison of liquid ethanol extraction (LEE) and SFE showed that SFE is greatly superior to LEE in colchicine separation with SFE not only higher yield and selectivity but also a quick, safe and non-toxic method were obtained in colchicine extraction.

Identification of occupational cancer risks in British Columbia. Part II: A population-based case-control study of 1516 Prostatic cancer cases

We have, as part of a program aimed at detecting occupational risk factors in British Columbia, collected lifetime occupational histories from 15,643 incident cancer cases, of whom 1519 had a diagnosis of prostate cancer. Occupational risks for this cancer site are examined using this large data set, and the results are presented in this report.