Human intestinal parasites in Subsaharan Africa. I. Eastern Boè and Canhabaque Island (Guinea-Bissau)

A coprological survey was carried out in 1982-1983 in East Boè and in Canhabaque Island, (Bijagòs Islands), where 289 and 288 specimens of stools, respectively, have been collected. The samples were taken from apparently healthy subjects, of both sexes and of different age groups. The tests were made according to the modified Ritchie technique. The following results were obtained: A) East Boè: 1) Protozoa: E. coli 68.9%, E. nana 24.6%, G. intestinalis 8.7%, I. buetschlii 5.9%, E. histolytica 1.7%, E. hartmanni 0.7%, T. intestinalis 0.7%. b) Helminths: Ancylostomatidae 69.2%, T. trichiura 38.4%, S. stercoralis 6.2%, Taenia sp. 1.7%, H. nana 0.7%, S. haematobium 0.7%, S. mansoni 0.7%, S. fuelleborni 0.7%. B) Canhabaque: a) Protozoa: E. coli 85.1%, I. buetschlii 14.9%, E. nana 12.5%, G. intestinalis 8.3%, C. mesnili 7.3%, E. hartmanni 1.4%, E. histolytica 1.0%, T. intestinalis 0.4%. b) Helminths: Ancylostomatidae 87.9%, T. trichiura 9.4%, S. stercoralis 7.9%, S. fuelleborni 2.8%, Trichostrongylus sp. 1.4%, A. lumbricoides 0.7%, H. nana 0.4%. Eggs of Capillaria sp. probably pseudoparasites, were found in 8.7% of samples. The high prevalence of Ancylostomatidae infections appears to be related to the heavy fecal pollution all over the examined territory. The utilization of antihelminthic drug of popular medicine, which has a specific action on A. lumbricoides, could explain the lack and the low prevalence, respectively, of A. lumbricoides infections in both examined areas. In the past, other authors emphasized the low prevalence of this parasite for other Guinea Bissau regions which have a different geomorfological constitution. The cases of S. fuelleborni and H. nana are the first reported for Guinea Bissau.     

An adenovirus mRNA which encodes a 14,700-Mr protein that maps to the last open reading frame of region E3 is expressed during infection.

The E3 regions of adenovirus types 2 and 5, respectively, are known to synthesize proteins of 19,000 Mr (19K) and 11.6K, but information regarding the identity and characterization of other potential E3 proteins encoded by the six remaining open reading frames (ORFs) is lacking. In this study, we show that the last ORF of region E3, which encodes a 14.7K protein, is expressed in adenovirus-infected cells. This information was largely derived from analysis of an E3 deletion mutant (H2dl801) in which an extensive deletion (1,939 base pairs) was found to eliminate all ORFs except for two proteins of 12.5K and 14.7K. The 14.7K protein was translated from RNA isolated from H2dl801-infected cells that had been hybridization selected to E3 DNA; hybridization-selected RNA from wild-type adenovirus type 5-infected cells translated both the 19K and the 14.7K proteins. Moreover, an antiserum directed against a bacterial 14.7K fusion protein (A. E. Tollefson and W. S. M. Wold, J. Virol. 62:33-39, 1988) immunoprecipitated the 14.7K translation product synthesized by wild-type and mutant H2dl801 adenovirus mRNAs.     

Characterization of the biosynthesis in vivo of α-aminoadipyl-cysteinyl-valine inPenicillium chrysogenum

Summary The parameters affecting the formation in vivo of -aminoadipyl-cysteinyl-valine (ACV), an intermediate in penicillin biosynthesis, have been established in low- and high-penicillin producing strains ofPenicillium chrysogenum. ACV was found both in cell extracts and in the culture broth filtrates. (¹⁴C)valine, -(¹⁴C)aminoadipic acid and (¹⁴C)cysteine were efficiently incorporated into ACV. Formation of ACV was stimulated by phenylacetic acid when added during the growth of the culture. ACV biosynthesis was enhanced when protein synthesis was blocked with cycloheximide or anisomicin. The ACV-synthesising activity of the culture increased between 24 and 48 h of the culture preceeding penicillin biosynthesis, and remained constant thereafter. A decay of ACV-forming activity was observed when de novo protein synthesis was inhibited with cycloheximide. The apparent half-life of the ACV-synthesising enzyme system was 2.5 h.     

Increased GH responsiveness to dopamine receptor stimulation in alcohol addicts during the late withdrawal syndrome

In humans the release of growth hormone (GH) elicited by dopamine (DA) and DA agonists may represent a reliable model to assess change in sensitivity of DA receptors. We now report that in chronic alcoholics, 4–7 days after the suspension of alcohol consumption, the increase of GH response to DA infusion was higher than that seen in non alcoholic volunteers. The specificity of this GH response to DA administration was demonstrated by the use of domperidone, a novel peripheral antagonist of DA receptors. These results suggest the development of hyper-responsiveness of DA receptors involved in the control of GH secretion in chronic alcoholics during the later phases of the “withdrawal syndrome”.     

Secondary structure features of ribosomal RNA species within intact ribosomal subunits and efficiency of RNA-protein interactions in thermoacidophilic (Caldariella acidophila,Bacillus acidocaldarius) and mesophilic (Escherichia coli) bacteria

Ribosomal subunits of Caldariella acidophila (max.growth temp., 90°C) have been compared to subunits of Bacillus acidocaldarius (max. growth temp., 70°C) and Escherichia coli (max. growth temp., 47°C) with respect to (a) bihelical content of rRNA; (b) G·C content of bihelical domains and (c) tightness of rRNA-protein interactions. The principal results are as follows. 1. Subunits of C. acidophila ribosomes (T_m = 90–93°C) exhibit considerable thermal tolerance over their B. acidocaldarius (T_m = 77°C) and E. coli counterparts (T_m = 72°C). 2. Based on the ‘melting’ hyperchromicities of the intact ribosomal subunits a 51–55% fraction of the nucleotides appears to participate in hydrogen-bonded base pairing regardless of ribosome source, whereas a larger fraction, 67–70%, appears to be involved in hydrogen bonding in the naked rRNA species. 3. The G·C content of bihelical domains of both free and ribosome-bound rRNA increases with increasing thermophily; based on hyperchromicity dispersion spectra of intact subunits and free rRNA, the bihelical parts of C. acidophila rRNA are estimated to contain 63–64% G·C, compared to 58.5% G·C for B. acidocaldarius and 55% G·C for E. coli. 4. The increment in ribosome T_m values with increasing thermophily is greater than the increase in T_m for the free rRNA, indicating that within ribosomes bihelical domains of the thermophile rRNA species are stabilized more efficiently than their mesophile counterparts by proteins or/ and other component(s). 5. The efficiency of the rRNA-protein interactions in the mesophile and thermophile ribosomes has been probed by comparing the releases, with LiCl-urea, of the rRNA species from the corresponding ribosomal subunits stuck to a Celite column through their protein moiety; it has been established that the release of C. acidophila rRNA from the Celite-bound ribosomes occurs at salt-urea concentrations about 4-fold higher than those required to release rRNA from Celite-bound E. coli ribosomes. 6. Compared to E. coli, the C. acidophila 50 and 30 S ribosomal subunits are considerably less susceptible to treatment designed to promote ribosome unfolding through depletion of magnesium ions.     

Thaimycins,new anthelmintic and antiprotozoal antibiotics produced by Streptomyces michiganensis var. amylolyticus var. nova

Summary A new microorganism, isolated in our laboratories and identified as Streptomyces michiganensis var. amylolyticus var. nova is described.Thaimycins can be obtained by submerged fermentation of this microorganism on a suitable culture medium.Three new related compounds, thaimycins A, B and C have been obtained and characterized by their physical and chemical properties.Data on the antiprotozoal and anthelmintic activities in vitro as well as in vivo are reported.