Pathology of congenital Zika syndrome in Brazil: a case series

Zika virus is an arthropod-borne virus that is a member of the family Flaviviridae transmitted mainly by mosquitoes of the genus Aedes. Although usually asymptomatic, infection can result in a mild and self-limiting illness characterised by fever, rash, arthralgia, and conjunctivitis. An increase in the number of children born with microcephaly was noted in 2015 in regions of Brazil with high transmission of Zika virus. More recently, evidence has been accumulating supporting a link between Zika virus and microcephaly. Here, we describe findings from three fatal cases and two spontaneous abortions associated with Zika virus infection.

Recombinant antigen-based immuno-slot blot method for serodiagnosis of syphilis

Three recombinant antigens of Treponema pallidum Nichols strain were fused with GST, cloned and expressed in Escherichia coli, resulting in high levels of GST-rTp47 and GST-rTp17 expression, and supplementation with arginine tRNA for the AGR codon was needed to obtain GST-rTp15 overexpression. Purified fusion protein yields were 1.9, 1.7 and 5.3 mg/l of cell culture for GST-rTp47, GST-rTp17 and GST-rTp15, respectively. The identities of the antigens obtained were confirmed by automated DNA sequencing using ABI Prism 310 and peptide mapping by Finningan LC/MS. These recombinant antigens were evaluated by immuno-slot blot techniques applied to 137 serum samples from patients with a clinical and laboratory diagnosis of syphilis (61 samples), from healthy blood donors (50 samples), individuals with sexually transmitted disease other than syphilis (3 samples), and from individuals with other spirochetal diseases such as Lyme disease (20 samples) and leptospirosis (3 samples). The assay had sensitivity of 95.1 percent (95 percent CI, 86.1 to 98.7 percent) and a specificity of 94.7 percent (95 percent CI, 87.0 to 98.7 percent); a stronger reactivity was observed with fraction rTp17. The immunoreactivity results showed that fusion recombinant antigens based-immuno-slot blot techniques are suitable for use in diagnostic assays for syphilis.

Photoisomerization of retinoic acid and its influence on regulation of human keratinocyte growth and differentiation.

Retinoic acid constantly undergoes structural inter-conversions among the geometrical isomers (all-trans-retinoic acid, 9-cis-retinoic acid, 11-cis-retinoic acid, 13-cis-retinoic acid and 9-13-di-cis-retinoic acid) by photoisomerization under natural light. Geometric isomers of retinoic acid thus formed showed different effects on human epidermal keratinocyte growth and differentiation. The ability of the isomers to inhibit the synthesis of cornified envelope (terminal event in the keratinocyte differentiation program) changed rapidly when illuminated by white fluorescent light. The 11-cis-retinoic acid had a 3-fold stronger activity to inhibit the growth of keratinocytes than the other geometric isomers. On the other hand, all-trans-retinoic acid, 9-cis-retinoic acid and 9-13-di-cis-retinoic acid exhibited a 3-fold greater ability to inhibit synthesis of involucrin, transglutaminase and the cornified envelopes. The regulation of keratin expression by the geometric isomers of retinoic acids was extremely complex. Level of keratin-1 (K1) mRNA was increased by 11-cis-retinoic acid and 13-cis-retinoic acid, but suppressed by 9,13-di-cis-retinoic acids while all-trans-retinoic acid and 9-cis-retinoic acid had no effect. Level of keratin-10 (K10) mRNA was strongly inhibited by all-trans-retinoic acid, 9-cis-retinoic acid and 11-cis-retinoic acid as compared to 13-cis-retinoic acid and 9,13-di-cis-retinoic acids. The mRNA level of keratin-14 (K14) was suppressed by all-trans-retinoic acid, 9-cis-retinoic acid and 11-cis-retinoic acid but not influenced by 13-cis-retinoic acid and 9,13-di-cis-retinoic acid. Natural light induced structural inter-conversions among the geometric isomers of retinoic acids in tissues-especially the skin, might play a crucial role in the regulation of growth and differentiation of keratinocytes.

Specific binding of Burkholderia pseudomallei cells and their cell-surface acid phosphatase to gangliotetraosylceramide (asialo GM1) and gangliotriaosylceramide (asialo GM2).

Specific binding between bacterial cells and host tissue is an early step of the pathogenesis of infection. Burkholderia pseudomallei cells, the causative micro-organisms of melioidosis, were demonstrated to bind specifically to tissue glycolipids (asialo GM1 and asialo GM2) by solid phase binding assay on thin layer chromatograms. The detection limit was around 400 pmol of the glycolipids. Acid phosphatase purified from the culture filtrate of B. pseudomallei was tested for such binding properties, and the same results were obtained. According to our previous studies, the enzyme is a glycoprotein located on the cell surface, and hydrolysed tyrosine phosphate most actively among the substrates so far tested. The mode of binding between the enzyme and the glycolipids was analyzed by comparison of binding levels among three samples different in protein content, sugar content and specific phosphatase activities per protein and sugar residue. The results suggested the possibility of a receptor-ligand relationship between the bacterial enzyme and the host-cell glycolipids (asialo GM).

Evaluation of shading of fish farming ponds as a larval control measure against Anopheles sundaicus Rodenwaldt (Diptera:Culicidae).

Larval density of Anopheles sundaicus in shaded and unshaded fish farming ponds was monitored at a coastal village in North Sumatra, Indonesia. The average density in the experimentally shaded ponds with Nipa leaves was reduced to < 1/10. Disappearance of algae and decline of water temperature also were observed, but the salinity did not change. The larval density was lower in ponds with Tilapia sp than without fish, but that in ponds with Ophiocephalus sp was not significantly lower. Dominant insects collected by dipping were Agrionidae and Libellulidae (Odonata), Corixidae, Notonectidae and Nepidae (Hemiptera), and Dytiscidae (Coleoptera). Density of nymphs of both Odonata and Notonectidae was higher in unshaded ponds. Taking into account longevity of the materials, and easiness in construction and applicability, shading by Nipa leaves was an easy and effective larval control measure against A. sundaicus in non-operating small fish farming ponds if leaves were renewed once in every two months.

Gametocytocidal effect of primaquine in a chemotherapeutic malaria control trial in North Sumatra, Indonesia.

The effect of primaquine as a gametocytocidal drug was investigated in 218 P. falciparum (Pf) malaria cases detected during passive case detection (PCD) from August to December 1985 in two coastal villages of North Sumatra, where chloroquine-resistant and Fansidar-sensitive Pf was prevalent. Sulfonamide + pyrimethamine (SP) in combination with primaquine (Pr) was administered in Kuala Tanjung village and SP alone in Nana Siam village. Parasitologically confirmed Pf cases were followed up to observe the fluctuation of gametocytemia after the treatment. In 87 cases treated with SP alone, no significant change was observed in gametocyte positivity rate (GPR) and density on day 2 and day 7. In 131 cases treated with SP and Pr, no significant change was found on day 2 but significant reduction was observed in GPR and density on day 7. The gametocyte positive cases on day 7 were followed up weekly until gametocytes disappeared. SP alone did not reduce GPR from day 0 to week 2, then afterward GPR began to decline but was still 11.5% at week 5. On the other hand, SP with Pr reduced GPR from 77% on day 0 to 30% on day 7, after which GPR declined further to 7% at week 3. Reduction of parasite rate was observed in Kuala Tanjung after the PCD activities, reflecting a reduction in Pf prevalence rate from 18.6% in August 1985 to 2.9% in January 1986. These data indicate that a single dose of Pr 45 mg with SP was partially effective in reducing gametocytes and reducing malaria prevalence rate when administered through PCD activities.

Studies on Malayan filariasis in Bengkulu (Sumatera), Indonesia with special reference to vector confirmation.

In an endemic focus of Brugia malayi in Bengkulu, Indonesia the microfilariae rate was 25%. The microfilariae showed nocturnal periodicity. Domestic cats in the same area were found to harbour B. pahangi, with a microfilariae rate of 23%. In the study area, the most prevalent man-biting Mansonia mosquitoes were Mn.bonneae (41%), followed by Mn.annulata (27%), Mn.uniformis (25%) and Mn.dives (7%). More Mansonia mosquitoes were collected outdoors than indoors between 1800-2200 hours. Natural infections with infective larvae of Brugia spp. were found in Mn.bonneae, Mn.dives, Mn.uniformis, Mn.annulata, and An.nigerrimus. Experimental infection studies revealed that Mn.annulata, Mn.bonneae, Mn.uniformis, An.nigerrimus and An.peditaeniatus permit the development of infective larvae. Under experimental condition, the vectorial competence is high in Mn.bonneae, intermediate in Mn.uniformis and low in An.hyrcanus group. It is concluded that the principal vectors of periodic B.malayi in the study area in Bengkulu are four Mansonia species (Mn.annulata, Mn.bonneae, Mn.uniformis and Mn.dives), and that the potential vectors include two Anopheles species (An.nigerrimus and An.peditaeniatus). This is the first record of Mn.bonneae being a vector of periodic B.malayi in Indonesia.