A modified nested polymerase chain reaction (PCR) method for detection of Plasmodium falciparum, P. vivax and P. malariae was combined with a simple blood collection and deoxyribonucleic acid (DNA) extraction method and evaluated in Malaysia. Finger-prick blood samples from 46 hospital patients and 120 individuals living in malaria endemic areas were spotted on filter papers and dried. The simple Chelex method was used to prepare DNA templates for the nested PCR assay. Higher malaria prevalence rates for both clinical (78.2%) and field samples (30.8%) were obtained with the nested PCR method than by microscopy (76.1% and 27.5%, respectively). Nested PCR was more sensitive than microscopy in detecting mixed P. falciparum and P. vivax infections, detected 5 more malaria samples than microscopy on the first round of microscopical examination, and detected malaria in 3 microscopically negative samples. Nested PCR failed to detect parasite DNA in 2 microscopically positive samples, an overall sensitivity of 97.4% compared to microscopy. The nested PCR method, when coupled with simple dried blood spot sampling, is a useful tool for collecting accurate malaria epidemiological data, particularly in remote regions of the world.

DNA, Protozoan↗

PubMedDate not supplied

Shear bond strengths produced by composite and compomer light cured orthodontic adhesives.

OBJECTIVES: To test the shear bond strengths obtained when orthodontic brackets were bonded ex vivo using a composite resin and a compomer orthodontic adhesive. METHODS: Specimens were tested in a special jig made to fit an Instron testing machine. After debonding, the adhesive remaining on bracket bases and enamel surfaces was mapped. RESULTS: Bond strengths ranged from 8 to 23 MPa with the composite resin producing higher strengths than the compomer for similar combinations of variables. Bond strength was increased by longer curing and a longer debond interval and was higher for brackets with mesh bases than undercut bases. More compomer remained on the enamel surface after debonding than did the composite resin. CONCLUSION: The compomer produced bond strengths within the range considered to be clinically acceptable in other studies. If it was clinically successful as an orthodontic adhesive a compomer would confer the advantage that fluoride release would help to minimize the onset of early caries around bonded brackets.

Acrylic Resins↗

PubMedDate not supplied

Knowledge of HIV transmission and risk behaviour in Kenyan health care workers.

In order to determine knowledge of HIV transmission, sexual risk behaviour and perception of risk in African health care workers, 200 employees at the Aga Khan Hospital, Nairobi, Kenya, were asked to complete an anonymous self-administered questionnaire. There was a 75% response rate. Twenty-five per cent believed that condoms were not protective against HIV transmission. Eighty-nine per cent believed oral sex to be a risk factor, as did 70% for kissing, 41% for masturbation of a partner and 43% for nursing an AIDS patient. Younger people were more likely to think condoms were ineffective (P = 0.007) and that insect bites were a significant risk factor (P = 0.004). Twenty-seven per cent had changed their sexual behaviour as a result of the AIDS epidemic, but 48% did not use condoms with non-regular partners. Four had current or previous homosexual relationships. Seventy per cent believed they were at risk of being HIV positive but only 12% had been tested. We have shown that even in the educated group, misconceptions regarding HIV transmission were high and many continue to be at risk for their sexual behaviour. In addition, in-service training regarding HIV transmission should be considered for health care workers in Africa.

Female↗

PubMedDate not supplied

Short report: differences in dihydrofolate reductase but not dihydropteroate synthase alleles in Plasmodium falciparum isolates from geographically distinct areas in Malaysia.

Dihydropteroate synthase (dhps) and dihydrofolate reductase (dhfr) alleles were typed in 67 Malaysian Plasmodium falciparum isolates. The isolates were collected from two geographically distinct locations: 51 from Sabah, Malaysian Borneo, where sulfadoxine/pyrimethamine (SDX/PYR) is used to treat uncomplicated malaria and 16 from Peninsular Malaysia where in vivo resistance to SDX/PYR has been reported. A total of seven dhps alleles were identified with no significant difference in allele frequency between the 2 populations. Two of the dhps alleles described here have not been previously reported. Four dhfr alleles were detected in 67 P. falciparum isolates. Eighty-seven percent of the isolates from the Peninsula, where clinical SDX/PYR failure has been reported, had dhfr alleles with triple point mutations while all of the isolates from Sabah had dhfr alleles with 2 or less point mutations. The difference in dhfr allele frequency between the two populations was highly significant. There was no correlation between in vitro PYR response and accumulation of dhfr point mutations.

Alleles↗