RNA polymerase II CTD S2P is dispensable for embryogenesis but mediates exit from developmental diapause in C. elegans.

Serine 2 phosphorylation (S2P) within the CTD of RNA polymerase II is considered a Cdk9/Cdk12-dependent mark required for 3'-end processing. However, the relevance of CTD S2P in metazoan development is unknown. We show that cdk-12 lesions or a full-length CTD S2A substitution results in an identical phenotype in Caenorhabditis elegans Embryogenesis occurs in the complete absence of S2P, but the hatched larvae arrest development, mimicking the diapause induced when hatching occurs in the absence of food. Genome-wide analyses indicate that when CTD S2P is inhibited, only a subset of growth-related genes is not properly expressed. These genes correspond to SL2 trans-spliced mRNAs located in position 2 and over within operons. We show that CDK-12 is required for maximal occupancy of cleavage stimulatory factor necessary for SL2 trans-splicing. We propose that CTD S2P functions as a gene-specific signaling mark ensuring the nutritional control of the C. elegans developmental program.

Behavior of aluminum electrodes in electrocoagulation process.

In the present work, electrocoagulation process with aluminum electrodes was investigated. Different operational conditions such as composition of Na(2)SO(4) based solutions, pH and current density were examined in a systematic manner. Their influence on (i) electrode polarization phenomena, (ii) pH evolution during electrolysis and (iii) the amount of Al released (coagulant) was investigated. For this purpose, potentiodynamic tests and electrolyses using different electrochemical cell configurations were conducted. It is mainly found that (i) a minimum Cl(-) concentration of the electrolyte of about 60ppm is required to breakdown the anodic passive film and considerably reduce the cell voltage during electrolysis; (ii) the anodic dissolution efficiency is unit; (iii) the global amount of coagulant (Al(3+)) generated has two origins: electrochemical oxidation of the anode and "chemical" attack of the cathode and (iv) electrolysis with Al electrodes acts as pH neutralization of the electrolytic medium. Taking into account advantage of the pH evolution observed during electrolysis, electrocoagulation tests were performed to treat a synthetic wastewater containing heavy metallic ions (Ni(2+), Cu(2+), Zn(2+)). Removal efficiencies over 98% were reached. Furthermore, our results displayed prominently that an increase of current density notably reduces the treatment duration without inducing a strong increase of the charge loading.

Three-dimensional computed tomographic evaluation of Le Fort III distraction osteogenesis with an external device in syndromic craniosynostosis.

There is little anteroposterior growth of the midface in patients with syndromic craniosynostosis who are followed up over time without intervention. A Le Fort III with distraction osteogenesis can be done to correct this. This is a controlled way in which to achieve appreciable stable advancement of the midface without the need for bone grafting, but the vector of the movement is not always predictable. The purpose of this study was to evaluate the 3-dimensional effect of Le Fort III distraction osteogenesis with an external frame. Ten patients (aged 7-19 years) who had the procedure were included in the study. The le Fort III procedure and the placement of the external frame were followed by an activation period and then a 3-month retention period. Computed tomographic (CT) images taken before and after operation were converted and loaded into 3-dimensional image rendering software and compared with the aid of a paired sample t test and a colour-coded qualitative analysis. Comparison of the CT data before and after distraction indicated that the amount of midface advancement was significant. Le Fort III distraction osteogenesis is an effective way to advance the midface. However, the movement during osteogenesis is not always exactly in the intended direction, and a secondary operation is often necessary. Three-dimensional evaluation over a longer period of time is necessary.

Cortisol levels in scalp hair of patients with structural heart disease.

BACKGROUND: Stress is considered a modifiable risk factor for cardiovascular disease. Scalp hair analysis is a tool to assess long-term exposure to the stress hormone cortisol. We aimed to determine the association between hair cortisol concentrations (HCC) and clinical characteristics in patients with structural heart disease. Additionally, we investigated potential predictors for longitudinal change in HCC. METHODS: The study consisted of 261 patients with structural heart disease from a randomized controlled trial of mindfulness training. One sample of scalp hair was used to determine HCC both at baseline and at 12-week follow-up. In 151 patients, HCC was available (mean age: 41.3 years, range 18-65). We investigated the association between HCC at baseline and several physiological measures (BMI, blood pressure, heart rate, respiratory rate, 6-minute walk test), as well as psychological parameters (physical and mental component summary measures (SF-36), emotional distress (HADS), and perceived stress). Additionally, we used these clinical parameters to predict HCC change over time. RESULTS: The median HCC was 22.3 pg/mg of hair (23.5 interquartile range). In multivariable linear regression analyses, an association was observed between log-transformed HCC and BMI (ß 0.171, p=0.037), respiratory rate (ß 0.194, p=0.016), and the physical summary score (ß -0.163, p=0.054). Independent predictors of log-transformed HCC change after 12 weeks were mental summary score (ß -0.200, p=0.019) and diastolic blood pressure (ß -0.171, p=0.049). CONCLUSIONS: In patients with structural heart disease a positive association exists between HCC and BMI. Mental health status may predict a change in long-term cortisol over time.

HU-GFP and DAPI co-localize on the Escherichia coli nucleoid.

The heterodimeric HU protein, one of the most abundant DNA binding proteins, plays a pleiotropic role in bacteria. Among others, HU was shown to contribute to the maintenance of DNA superhelical density in Escherichia coli. By its properties HU shares some traits with histones and HMG proteins. More recently, its specific binding to DNA recombination and repair intermediates suggests that HU should be considered as a DNA damage sensor. For all these reasons, it will be of interest to follow the localization of HU within the living bacterial cells. To this end, we constructed HU-GFP fusion proteins and compared by microscopy the GFP green fluorescence with images of the nucleoid after DAPI staining. We show that DAPI and HU-GFP colocalize on the E. coli nucleoid. HU, therefore, can be considered as a natural tracer of DNA in the living bacterial cell.

Overproduction and improved strategies to purify the threenative forms of nuclease-free HU protein.

The heterodimeric HU protein was isolated from Escherichia coli as one of the most abundant DNA binding proteins associated with the bacterial nucleoid. HUalphabeta is composed of two very homologous subunits, but HU can also be present in E. coli under its two homodimeric forms, HUalpha(2) and HUbeta(2). This protein is conserved either in its heterodimeric form or in one of its homodimeric forms in all bacteria, in plant chloroplasts and in some viruses. HU can participate, like the histones, in the maintenance of DNA supercoiling and in DNA condensation. This protein which does not recognize any specific sequence on double-stranded DNA, has been shown to bind specifically to cruciform DNA as does the eukaryotic HMG1 protein and to a series of structures which are found as intermediates of DNA repair, e.g., nick, gap, 3'overhang, etc. The strong binding of HU to these diverse DNA structures could explain, in part at least, its pleiotropic role in the bacterial cell. To understand all the facets of its interactions with nucleic acids, it was necessary to develop a procedure which allowed the purification of the three forms of HU under their native form and without the nuclease activity strongly associated with the protein. We describe here such a procedure as well as demonstrating that the three histidine-tagged HUs we have produced, have conserved the binding characteristics of native HUs. Interestingly, by two complementation tests, we show that the histidine-tagged HUs are fully active in vivo.

Difluoromethylornithine, an effective new treatment of Gambian trypanosomiasis. Results in five patients.

Recent studies have shown DL-alpha-difluoromethylornithine (eflornithine), an inhibitor of polyamine biosynthesis, to be curative in various Trypanosoma species infections of laboratory animals. Five patients are described with Gambian trypanosomiasis treated in Belgium with difluoromethylornithine, using various intravenous and oral dosage schedules. Three patients had late-stage and two had early-stage disease. Difluoromethylornithine treatment was associated with clearing of parasites from blood within one to four days, a trend towards normalization of all altered biologic values associated with the disease, and marked amelioration of clinical symptoms. Side effects of difluoromethylornithine, including loose stools in three patients and both anemia, and a decrease in auditory acuity in one patient, were mild, transient, and never required interruption of drug treatment. The presence of difluoromethylornithine in cerebrospinal fluid, determined in three patients, demonstrated that difluoromethylornithine penetrates into the central nervous system. In three patients, follow-up of at least 24 months after treatment demonstrated a continued healthy state without evidence of relapse. These promising, albeit preliminary, results of difluoromethylornithine therapy, even in patients with central nervous system involvement, indicate that extended clinical trials are warranted to determine the optimal dosage regimen in patients with early- and late-stage disease.

Simultaneous use of Plasmodium falciparum crude antigen and red blood cell control antigen in the enzyme-linked immunosorbent assay for malaria.

An enzyme-linked immunosorbent assay for malaria, based upon duplicate testing of serum samples on both a crude Plasmodium falciparum antigen and a red blood cell control antigen, is evaluated. Results were analyzed using the Student's t-test for identification of positive serum samples (t greater than or equal to 2.92, P less than or equal to 0.05) and for calculation of the mean difference in absorbance values (delta ABS) obtained between the P. falciparum wells and the control wells. Cross-evaluation with the IFA test for P. falciparum antibodies gave 89.6% concording positive or negative results. Among discrepant sera 8.35% were ELISA+/IFA- and 2.05% ELISA-/IFA+. In addition, delta ABS values in ELISA were highly correlated to titers obtained in immunofluorescence (r = 0.80, P less than 0.001). The results confirm the high degree of species-specificity of the ELISA using P. falciparum crude antigen. The necessity of the simultaneous use of red blood cell control antigen with a crude plasmodial antigen is demonstrated by comparing the presented results with those obtained on the P. falciparum antigen only.

Detection of antibodies to Plasmodium vivax by indirect immunofluorescence: influence of the geographic origin of antigens and serum samples.

The results of a double-blind serological study of 15 sera sampled in a residual focus of vivax malaria transmission in Algeria, and of 7 sera from patients with slide-proven P. vivax infections acquired in India, are analyzed. The reactivity of each of these serum samples was tested by indirect immunofluorescence using 6 different batches of antigen, including 3 batches of P. vivax antigen prepared with isolates from Zaire (Africa), India and the Solomon Islands, respectively. The geometric mean of reciprocal titers (GMRT) calculated on the 7 sera from proven vivax infections fell from 289.8 using the homologous antigen from the same geographic origin (India) to 48.7 using a homologous (vivax) antigen originating from a different continent (Africa). Among the 15 samples from Algeria, the percentage of seropositives decreased from 100% using the homologous P. vivax antigen originating from the same continent (Africa) to 53.3% using a homologous antigen from India. Two aspects are included in the discussion: in seroepidemiological studies, sensitivity could be improved by the use of a homologous antigen from the same geographic origin; in detection of clinical cases of malaria and species identification based on serology, our results stress the need for caution in interpreting serological titers and for taking into account the geographic origin of the isolates used as antigen.

Renal disease in chronic experimental Trypanosoma gambiense infections.

Two recently isolated stocks of Trypanosoma brucei gambiense of human origin gave rise to a moderate to severe proliferative or membranoproliferative glomerulonephritis in 40 or 44 NMRI and C57BL/6J mice infected for 7-22 weeks. Extensive granular deposits of C3, IgG1 and IgG3 were found in the mesangium, together with smaller quantities of IgG2a, IgG2b, and IgM. No trypanosomal antigen could be detected in the deposits though specific anti-trypanosoma antibodies were found in kidney eluates. By electron microscopy, a conspicuous proliferation of mesangial and endothelial cells was observed and electron-dense deposits were seen in a mesangial and subepithelial localization. With one of these trypanosome stocks, four of seven Wistar rats infected for 9-15 weeks developed morphologically similar glomerular lesions. Four other trypanosome stocks did not evoke renal alterations in 17 other rats infected for 13-56 weeks. Experimental infection in mice or rats appears to be a suitable model for the study of renal disease in chronic African sleeping sickness.

Drug used in the treatment of sleeping sickness (human African trypanosomiasis: HAT).

From the first decade of this century arsenicals have been the most universal and most effective drugs for all cases of sleeping sickness. Melarsoprol, introduced in the 1940s, remains the most universal of these compounds. However, resistance of trypanosomes and toxicity that may be fatal for the patient are two major shortcomings. Pentamidine, suramin and Berenil((R)) are active only in the first stage of the disease, when the parasites are confined to blood and lymph. Nifurtimox taken orally for 1 to 2 months and alpha-difluoro-methylornithine (alpha-DFMO) with an administration scheme spread over 5 weeks including 14 days of intravenous injections. provide interesting alternatives for all cases, since they reach the central nervous system. However, DFMO is known to be less active against. T. rhodesiense. Imidazoles, new arsenical derivatives and antimitotics have been successfully tested in experimental models. Combinations of drugs with additive or pontentiating effects mainly based on inhibition of decarboxylase enzymes or exposure to axidative stress appear promising.

Double-blind study to assess the efficacy of chlorproguanil given alone or in combination with chloroquine for malaria chemoprophylaxis in an area with Plasmodium falciparum resistance to chloroquine, pyrimethamine and cycloguanil.

In this study the efficacy of chlorproguanil (20 mg base weekly) was compared in schoolchildren with that of chloroquine (200 mg base weekly) and that of both drugs combined (20 mg base + 200 mg base weekly). The double blind trial was performed in the rice field area of the Ruzizi valley in Burundi, where Plasmodium falciparum is widely resistant to chloroquine, and where pyrimethamine resistance with cycloguanil cross-resistance had been demonstrated. After 17 weeks, when the trial was ended, 60% breakthroughs had been observed among the children taking chloroquine, 72% among those under chlorproguanil and 61% among those under chlorproguanil and chloroquine. In children weighing between 15 and 24 kg, the failure rate was significantly higher in those treated with chlorproguanil than in the group treated with chloroquine. No difference in efficacy was observed in children weighing 25 to 39 kg. There was no significant increase of efficacy when chlorproguanil was given in association with chloroquine. The mean titre of fluorescent antibodies was the same in each treated group on week 5 and week 15. The comparison of these data with the infection rates in non-protected children suggests that malaria could not be prevented with any of the drug regimens utilized in the study.

Demographic findings relevant for health care planning and evaluation collected through a malaria control project in the Kivu Mountains, Zaire.

Population studies were conducted in the margin of a community based malaria control programme in the Katana Health zone, in the Eastern part of Zaire. The reported findings are based on prospective registration of vital events from March 1986 through February 1987. At mid term 28.083 people were covered. The age and sex structure of the population was typical for tropical Africa, apart from an excess of males to females after the age of 64. The mean age at marriage was 21.2 years for women and 25.6 years for men. 89% of women did not complete a single year of formal education. The crude fertility rate was 250/1000 and total fertility 8.3 children. The infant mortality rate and the child mortality quotients attained 130/1000 and 183/1000 respectively. The crude death rate was 23 per 1000 and the natural population growth rate 31/1000. Due to a net out-migration of 28/1000 the zone's population remained, however, virtually stable. The latter observation questions the purported role of demographic pressure as a key determinant of the region's slow socio-economic development. The other findings provide valuable baseline and background information for planning and evaluating health-related activities.

PIP: High population growth rates have been considered a major problem in the Kivu region of Zaire and a key issue for the future development of the rural areas situated near Kivu lake. Overpopulation and the resulting land shortage were held responsible for the disastrous nutritional situation and the population explosion was said to limit the impact of health care activities. A paucity of recent demographic data for the region, however, has made it difficult to assess whether these claims are valid. The authors report findings from population studies conducted in the margin of a community-based malaria control program in the Katana Health zone in the eastern part of Zaire. Findings are based upon the prospective registration of vital events from March 1986 through February 1987. 5497 households were counted and 28,083 people were covered at midterm. 19.9% of the population was younger than 5 years old, 47.3% under age 15, and 3.7% above age 64. Women aged 15-49 comprised 21.5% of the total population. The mean age at marriage was 21.2 years for women and 25.6 for men, with more than 40% of the elder men having more than one wife. 89% of the women had not completed one year of formal education. The crude fertility rate was 250% with total fertility at 8.3 children per woman. The rate of infant mortality was 130%, the child mortality quotient was 183%, the crude death rate was 23 per 1000, and the rate of natural population growth was 31%. The net out-migration rate of 28% toward less populated rural or urban areas, however, kept the zone's population size almost stable. Increasing demographic pressure can therefore probably not be held responsible for the region's economic stagnation. Dependence upon customary authorities, the land tenure system, and the quasi-feudal organization of agricultural production and crop commercialization seem to offer more plausible explanations.

Quantitative determination of hydrogen in solids by gas chromatography.

Processes such as electroplating or acid cleaning are notorious causes of post-processing failure through hydrogen embrittlement. So, the determination of amounts of hydrogen in metals is of great importance. An analysis method for investigation of H content in solids has been established based on hot extraction and gas chromatography system. Hot extraction in inert gas enables complete and/or partial removal of the hydrogen from the samples. A gas chromatography system is used to determine quantitatively the amount of thermally desorbed hydrogen. An investigation of the baking operating conditions is made of the hydrogen desorption rate of zinc-plated steel parts. Then, an analysis of the polarisation conditions upon chromium electroplating is given.

Screening of Rwandese medicinal plants for anti-trichomonas activity.

A series of 30 medicinal plants used in Rwandese traditional medicine has been screened for anti-trichomonas activity against the protozoan Trichomonas vaginalis. Seventeen plants showed anti-trichomonas activity.

The role of the host during the development of Plasmodium berghei hepatic schizonts.

Immature exoerythrocytic stages of Plasmodium berghei are immunogenic and produce antigens with protective capacities. Immunization experiments show a strong dependency of the responses on the host species and strain. To study this dependency a potential natural host of Plasmodium berghei, Thamnomys gazellae, was introduced, a species which is very susceptible for infection. Young liver stages were produced in different hosts after inoculation with irradiated sporozoites or after treatment with difluoromethylornithine.

[Seroepidemiology of malaria in a residual focus in Algeria: Khemis El Kechua district]. / Séroépidémiologie du paludisme au niveau d'un foyer résiduel en Algérie: commune de Khemis El Kechna.

The residual focus of Khemis el Kechna represented in 1981 nearly the totality of the autochtonous cases detected in Algeria that year (51 cases/53 cases). Control measures were applied during 3 successive years, the number of cases dropped from 51 in 1981 to 18 in 1982 and to 0 in 1983. In order to confirm the interruption of malaria transmission a sero-epidemiological study was carried out in 1984. The analysis of serological results by age, time and place of residence led to the conclusion that malaria transmission no longer occurs. A comparison of the serological results obtained by two blood sampling techniques (serum/dried blood on filter paper) confirmed the reliability of the results when eluted dried blood is used. A statistically significant difference was observed between the proportions of positives sera according to the antigen species used (P. falciparum culture strain or P. vivax obtained from patient originating from India.

[Study of general mortality and of mortality related to malaria in the mountains of Kivu, Zaire]. / Etude de la mortalité globale et de la mortalité liée au paludisme dans le Kivu montagneux, Zaïre.

A longitudinal study in the "health region" of Katana (Kivu, Zaïre) has permitted to determine age and disease specific mortality rates. The infant mortality rate is 172 per 1000/year, the child mortality rate 45 p.1000/year and the crude rate 24 p.1000/year. Two thirds of this mortality are related to infectious and parasitic diseases: measles, diarrhoea, respiratory diseases and malaria. In the mountainous Katana region (4500 feet), malaria is responsible for 12%, of the decrease and the specific mortality rates are 3 p.1000/year in the general population and 18 and 6 p.1000/year in, respectively, the 0 to 11 month and 1 to 4 year age groups. We discuss the potential of PHC to improve, in the framework of an integrated development approach, this unfavorable health situation.

Rodent malaria parasites: molecular karyotypes characterize species, subspecies and lines.

The molecular karyotypes of the African murine malaria parasites P. berghei (3 strains, 2 lines) P. yoeli (2 strains) P. chabaudi (3 strains, 1 line) and P. vinckei (4 strains) have been studied using orthogonal field alternation gel electrophoresis (OFAGE). The genome of each species was resolved into 9 to 11 distinct chromosomal DNA banas molecules of varying intensities which seem to represent 14 chromosomes ranging in size from 600 kb to 3500 kb. The position of certain chromosomes allowed the identification of a unique karyotype for each of the strains and lines under study. P. yoelii appears by criteria of chromosome size, chromosome numbers and localisation of DNA probes to differ considerably from the other three rodent malaria species. The chromosomal location of 5 DNA probes allowed the identification of corresponding chromosomes in rodent malaria parasites and the differentiation between species and strains. Assignment of the "PMMSA" gene of P. c. chabaudi IP-PC 1 enables the distinction of the four rodent malaria species. The molecular karyotype combined to chromosomal assignment of DNA probes provides a useful tool for a more precise characterization by a genetic definition of malaria parasites.

[Changes in plasma lipid levels as a function of Plasmodium falciparum infection in São Tomé]. / Variations dans les taux de lipides plasmatiques en fonction de l'infection à Plasmodium falciparum à São Tomé.

Changes in lipid plasma levels during malaria attacks have been proposed for use in diagnosis or to assess the severity of the disease. In order to analyse the plasma levels of cholesterol, triglycerides, HDL-C et LDL-C, we compared, in an endemic area (São Tomé island), two groups of patients children infected with Plasmodium falciparum (simple malaria attack and cerebral malaria) with a control group of asymptomatic children. No correlation between lipid plasma levels and disease severity was found. Correlations between lipids and parasitemia or anemia were analysed. The mechanism of plasma lipid changes during attack are discussed.