Low sensitivity of polymerase chain reaction for diagnosis of tuberculous meningitis in southeastern Brazil

Two polymerase chain reaction (PCR) protocols showed low sensitivity (36% and 53% for TB AMPLICOR and MPB64 nested PCR, respectively), when compared with classic microbiological methods (73% and 54% for Ziehl-Neelsen staining and culture, respectively), in the diagnosis of tuberculous meningitis in 91 patients in southeastern Brazil. Only three PCR-positive, microbiologically negative patients were found. Analysis of sequential cerebrospinal fluid samples by nested PCR detected Mycobacterium tuberculosis DNA up to 29 days after the introduction of antituberculosis chemotherapy.

Exames coproparasitológicos realizados em 191 crianças de creches e em 434 alunos da primeira à quarta série das áreas urbana e rural da rede municipal de Rolândia, PR, evidenciaram enteroparasitas em prevalência de 15,2% nas creches e de 52,5% entre os escolares. Fatores de risco são discutidos.

Sequence diversity of serine repeat antigen gene exon II of Plasmodium falciparum in worldwide collected wild isolates.

Field isolates of Plasmodium falciparum collected from endemic areas of Southeast Asia, Solomon Islands, tropical African countries and Brazil were analyzed for the genetic diversity of the exon II of serine repeat antigen gene (SERA) by sequencing of genomic DNA. Of sixty-nine isolates, as compared to the reported FCR3, K1 and Honduras-1 types of exon II sequences, 5, 9 and 20 new allelic forms were found in 23 isolates of the FCR3 type, 36 of the K1 type and 10 of the Honduras-1 type. A group of novel non-synonymous substitutions, 4 new insertions and 3 new deletions of octamer units were found in the octamer repeat region (OR) of the exon II, and most of them clustered within a 40-residues domain. An octamer "SNPVSSEP" revealed in the OR was confirmed as a new repeat unit. Based on the sequences of the serine repeat region (SR) of the exon II, the allelic forms of the Honduras-1 type were conjectured to be the recombinant forms between the K1 type and FCR3 type. The allelic forms of K1 type with less or more repeat serine residues in the serine stretch of the SR than the reported 21 serine residues had most of the variations in the OR. Moreover, a biased geographical distribution of allelic forms was observed. Isolates from African and Southeast Asian countries accounted for most of the new allelic forms (29/33). All of the three types were detected in Southeast Asia but none of the FCR3 type in Africa. One of two groups of FCR3 new allelic forms was found solely in Brazil while another was mainly in Solomon Islands.

The seroprevalence of hepatitis B and C in an Amerindian population in the southwestern Brazilian Amazon

A soroprevalência de hepatite B e C foi investigada na comunidade indígena Karitiana (n = 119), que habita o Estado de Rondônia, Amazônia Ocidental Brasileira. A prevalência de anticorpos anti-HBs e anti-HBc foi respectivamenre de 16,1 por cento e 35,3 por cento, sendo detectado HBsAg em somente quatro (3,4 por cento) indivíduos. Anticorpos anti-HCV foram encontrados em dois (1,7 por cento), indivíduos. Os dados estratificados por idade sugerem que tanto as vias de transmissäo vertical como horizontal (esta entre adultos) säo importantes nesta comunidade

Effect of dietary iron on the course of Plasmodium berghei malaria in young rats

Clinical and experimental evidence suggests that iron-deficient hosts are less susceptible to severe malaria and that iron supplementation aggravates infection. In the present study, 60 weanling Wistar rats were fed standard diets with different iron concentrations: 21 mg/kg (group 1), 45 mg/kg (group 2) and 113 mg/kg (group 3). Ferrous sulfate (FeSO4 x 7H2O) was added to the normal-iron and iron-supplemented diets (groups 2 and 3, respectively). Data are reported as mean +/- SEM. After 16 days of regimen, eight rats from each group were killed to measure serum iron concentration (SI) and transferrin saturation capacity (TSC). At this moment, rats from group 1 were underweight and their dietary intake was significantly lower than that of animals from the other groups. Severe iron deficiency (SI = 49.2 +/- 4.5 micrograms/100 ml and TSC = 8.3 +/- 0.7 per cent ) was observed in rats from group 1, while the animals from the other groups were iron-sufficient (group 2: SI = 186.5 +/- 28.5 micrograms/100 ml and TSC = 27.3 +/- 3.4 per cent ; group 3: SI = 137.3 +/- 18.2 micrograms/100 ml and TSC = 21.3 +/- 2.3 per cent ). Nine animals from each group were then infected with the malaria parasite Plasmodium berghei, whereas three animals from each group were used as noninfected controls. Parasitemias ( per cent of infected red blood cells) peaked 7 days post-infection in animals from groups 2 and 3 (mean values of 2.4 per cent and 1.7 per cent , respectively), but in animals from group 1 parasitemias increased until the 9th day post-infection (mean at peak, 2.3 per cent ) and parasite clearance was significantly slower than in the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple reflectance microphotometer for dot immunobinding assay (dot-ELISA) quantification

The use of a simple reflectance microphotometer adapted to quantify enzymatic dot immunobinding assays is described. The instrument is versatile and precise by clinical laboratory standards (i.e., 1.1%coeficient of variation for ten consecutive readings of a grey cardboard). The instrument provide a low-cost alternative to commercially available equipment for quantitation of dot-ELISA assays