Immunisation in a curative setting.

OBJECTIVE--To study the uptake of vaccination offered to women and children attending a curative health facility. DESIGN--Prospective survey over eight months of the uptake of vaccination offered to unimmunised women and children attending a diarrhoeal treatment centre as patients or attendants. SETTING--The International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh. SUBJECTS--An estimated 19,349 unimmunised women aged 15 to 45 and 17,372 children attending the centre for treatment or accompanying patients between 1 January and 31 August 1989. MAIN OUTCOME MEASURES--The number of women and children who were unimmunised or incompletely immunised was calculated and the percentage of this target population accepting vaccination was recorded. RESULTS--7530 (84.2%) Of 8944 eligible children and 7730 (40.4%) of 19,138 eligible women were vaccinated. Of the children, 63.8% were boys, 75.9% were aged under 1 year, and 23.0% were aged 1 to 2 years. The estimated number of missed opportunities for vaccination was 716 among the children (8.0% of the target population) and 11,408 among the women (59.6% of those eligible). CONCLUSION--It is possible to establish immunisation services at a health facility treating acutely ill patients.     

Sodium valproate inhibits the movement of secretory vesicles in rat hepatocytes.

Sodium valproate (VPA), a simple 8-carbon branched chain fatty acid, is an effective anti-epileptic drug with an occasional serious side effect of liver damage, including the accumulation of triacylglycerols within hepatocytes, and reductions in serum protein concentrations. By investigating the effects of VPA, using biliary fistula rats and isolated perfused rat livers, we have shown that secretion of triacylglycerols and rat serum albumin at the sinusoidal pole of hepatocytes, and of phospholipids, lysosomal contents, and IgA at their biliary pole, are all reduced, to somewhat different extents, by acute VPA administration. In addition, the vesicular transcytosis of exogenous protein (i.e. bovine serum albumin) from the perfusion fluid into bile is also decreased by VPA administration. To determine whether the phenomena were specific to VPA, a control series of experiments was also performed using octanoate (a straight-chain analogue of VPA). With the biliary fistula rats, octanoate did not show inhibition of secretion as compared with the saline controls; with the isolated perfused livers, however, octanoate did show such an inhibition. These phenomena suggest that VPA inhibition of secretion may be a factor in its hepatotoxicity, as the effects are apparent in both the whole animal and the isolated perfused liver, whereas octanoate is not hepatotoxic in the whole animal. Since when octanoate is administered to the isolated liver it causes an inhibition in secretion similar to that caused by VPA, it may be that the large dose of this compound reaching the liver affects a key step in liver metabolism or vesicle transport under these circumstances. Since octanoate does not normally reach the liver in such amounts, as it will normally be metabolized by other tissues, it is not hepatotoxic in the whole animal as is VPA.     

In vitro propagation ofMitragyna parvifolia Korth.

Multiple shoot formation and their elongation from excised apical vegetative shoots of a 40-year old-tree ofMitragyna parvifolia Korth. was achieved in Murashige and Skoog's medium supplemented with 4.44 M benzyl adenine. The in vitro regenerated shoots rooted when cultured on modified Murashige and Skoog's medium containing low inorganic salts and the three auxins. Regeneration by this method was suitable for mass propagation of the plant.     

Mini-exon derived RNA gene ofLeishmania donovani: structure,organization and expression

Mini-exon derived RNA is a small nuclear RNA of trypanosomatid protozoa such asLeishmania which donates its 5′-terminal 39 nucleotides to the 5’-ends of cellular messenger RNAs by trans-splicing. We have cloned a mini-exon derived RNA gene fromLeishmania donovani and studied its organization and expression. About 200 copies of the gene per haploid genome are organized as a tandem repeat on a single chromosome. The gene is transcribed as a 95-nucleotide RNA. The first 39 nucleotides of mini-exon derived RNA is also found at the 5′-terminus of a cellular mRNA (Β-tubulin), thus confirming its identity. Sequence analysis of the gene and its flanking regions showed that while classical RNA polymerase II promoter elements such as TATA and CAAT are absent from the 5′-upstream region, intragenic sequence motifs resembling RNA polymerase III promoter elements are present. The implications of this finding for mini-exon derived RNA expression are discussed.     

DNA helicase III from HeLa cells: an enzyme that acts preferentially on partially unwound DNA duplexes.

Human DNA helicase III, a novel DNA unwinding enzyme, has been purified to apparent homogeneity from nuclear extracts of HeLa cells and characterized. The activity was measured by using a strand displacement assay with a 32P labeled oligonucleotide annealed to M13 ssDNA. From 305 grams of cultured cells 0.26 mg of pure protein was isolated which was free of DNA topoisomerase, ligase, nicking and nuclease activities. The apparent molecular weight is 46 kDa on SDS polyacrylamide gel electrophoresis. The enzyme shows also DNA dependent ATPase activity and moves unidirectionally along the bound strand in 3' to 5' direction. It prefers ATP to dATP as a cofactor and requires a divalent cation (Mg2+ > Mn2+). Helicase III cannot unwind either blunt-ended duplex DNA or DNA-RNA hybrids and requires more than 84 bases of ssDNA in order to exert its unwinding activity. This enzyme is unique among human helicases as it requires a fork-like structure on the substrate for maximum activity, contrary to the previously described human DNA helicases I and IV, (Tuteja et al. Nucleic Acids Res. 18, 6785-6792, 1990; Tuteja et al. Nucleic Acids Res. 19, 3613-3618, 1991).     

Compliance with diphtheria,tetanus, and pertussis immunisation in Bangladesh: factors identifying high risk groups.

OBJECTIVE--To evaluate factors associated with non-compliance with having second vaccination against diphtheria, tetanus, and pertussis in a treatment centre in Dhaka to determine which children were most at risk of not completing immunisation. DESIGN--Cohort study of infants given first dose of the vaccine and followed up six weeks later to ascertain compliance with having second dose. Factors associated with non-compliance were evaluated. SETTING--Dhaka treatment centre of the International Centre for Diarrhoeal Disease Research, Bangladesh. SUBJECTS--136 unimmunised children aged 6 weeks to 23 months who lived within reach of the treatment centre. At time of the six week follow up 16 of the children could not be traced and seven had died. INTERVENTIONS--All children received their first dose of the vaccine. In each case health education workers had informed the mother about the value of immunisation, and she was given clear instructions to bring the child back after four weeks for the second dose. MAIN OUTCOME MEASURE--Rate of non-compliance with advice to return child for second vaccination. RESULTS--46 of 113 children (41%) received the second dose of the vaccine. Factors most closely associated with mothers'' failure to comply with the second dose were lack of education and low income. Children whose mothers knew most about immunisation at first interview were more likely to have their second dose. CONCLUSIONS--Preventive health care services such as immunisation are appropriately offered in treatment centres, but compliance among children varies with socioeconomic status and mother''s education. Further research should be aimed at ways to make health education more effective among uneducated parents.     

Molecular evolution of the seed storage proteins of barley, rye and wheat

The major storage proteins (prolamins) of barley, rye and wheat are characterized by the presence of two or more unrelated structural domains, one of which contains repeated sequences. Because of this repetitive structure and their restricted distribution (only in grasses), it has been suggested that the prolamins are of recent origin. Contrary to this hypothesis, we show that parts of the non-repetitive domain of one group of prolamins are homologous with sequences present in a large group of seed proteins from monocotyledonous and dicotyledonous plants; including Bowman-Birk protease inhibitors, cereal inhibitors of alpha-amylase and trypsin, and 2 S globulin storage proteins of castor bean and oil seed rape. This implies an ancient origin for these non-repetitive domains. The origins of the repetitive domains are not known but may lie within the grasses.     

Breeding of Barbus bynni (Pisces,Cyprinidae) in Jebel Aulia Reservoir,Sudan

Barbus bynni begins to mature at Age IV. Ripening of gonads of mature fish starts in May when water temperature approaches the annual maximum. However, the spawning season coincides with the onset of the flood season in July. These facts, as well as the cyclic growth of the gonads, show that B. bynni spawns once a year. Fecundity varies with size of fish and gonads. However, this levels off in the middle size group. At this age the fecundity was estimated to be 1 424 693 eggs.     

Food and feeding habits of Labeo niloticus (Pisces,Cyprinidae) in Jebel Aulia Reservoir,Sudan

Basic knowledge on the feeding ecology of one of the common and commercially important fish species in Jebel Aulia Reservoir is provided.The structure of the feeding apparatus indicates that Labeo niloticus is a bottom feeder, depending on soft and decayed vegetation, organic debris and whatever small organisms found within. However, juveniles and fry are prone to explore all layers and depths of the river selectively for plankton. There is little evidence of seasonal selection of food. Changes in diet quality are governed by the availability of type of food. Variability of feeding activity is connected with climate and breeding season.     

Ecological relationships between Vibrio cholerae and planktonic crustacean copepods.

Strains of Vibrio cholerae, both O1 and non-O1 serovars, were found to attach to the surfaces of live copepods maintained in natural water samples collected from the Chesapeake Bay and Bangladesh environs. The specificity of attachment of V. cholerae to live copepods was confirmed by scanning electron microscopy, which revealed that the oral region and egg sac were the most heavily colonized areas of the copepods. In addition, survival of V. cholerae in water was extended in the presence of live copepods. Attachment of viable V. cholerae cells to copepods killed by exposure to -60 degrees C was not observed. Furthermore, survival of V. cholerae was not as long in the presence of dead copepods as in the live copepod system. A strain of Vibrio parahaemolyticus was also seen to attach to copepod surfaces without effect on survival of the organism in water. The attachment of vibrios to copepods was concluded to be significant since strains of other bacteria, including Pseudomonas sp. and Escherichia coli, did not adhere to live or dead copepods. Attachment of V. cholerae to live copepods is suggested to be an important factor of the ecology of this species in the aquatic environment, as well as in the epidemiology of cholera, for which V. cholerae serovar O1 is the causative agent.