Effect of Hydraulic retention time on performance of anaerobic membrane bioreactor treating slaughterhouse wastewater

Slaughterhouse wastewater is a major environmental concern in many Vietnamese cities due to its high organic content and unpleasant odor. This study aimed to evaluate performance of a submerged flat sheet Anaerobic membrane bioreactor (AnMBR) system at different hydraulic retention time (HRT, 8-48 h) treating wastewater from a slaughterhouse in Hanoi City (Vietnam) at ambient temperature. The wastewater characteristics were as follows: chemical oxygen demand (COD) of 910 ± 171 mg/L; suspended solids (SS) of 273 ± 139 mg/L; and total nitrogen (T-N) of 115 ± 31 mg/L. The AnMBR system achieved high removal efficiencies for SS (99%) and COD (>90%) at an optimum HRT of 24 h. The biomethane yield reached 0.29 NL CH4/g CODinf. Importantly, the system maintained stable operation without flux decay and membrane fouling. HRT longer than 24 h could offer the better effluent quality without an increase in transmembrane pressure (TMP); however, it led to a lower methane production rate. Shorter HRT of 8-12 h caused a high TMP over -10 kPa, posing a risk for membrane fouling and biomass loss during cleaning, thus resulting in a low methane production. Our results suggest that AnMBR can be a reliable technology for wastewater treatment, reuse and energy recover from slaughterhouse wastewater in Vietnam and other similar climate countries.

Effect of carbohydrates on protein hydrolysis in anaerobic digestion

This study aimed to assess the effect of carbohydrates on protein hydrolysis and potential implications for the design of anaerobic reactors for treatment of protein-rich wastewaters. Batch experiments were carried out with dissolved starch (Sta) and gelatine (Gel) at different chemical oxygen demand (COD) ratios ranging from 0 to 5.5 under methanogenic conditions for methane production and up to 3.8 under non-methanogenic conditions for volatile fatty acids (VFA), both at 35 °C. The Sta/Gel did not have a direct effect on the gelatine hydrolysis rate constants under methanogenic (0.51 ± 0.05 L g VSS^-1 day^-1) and non-methanogenic conditions (0.48 ± 0.05 L g VSS^-1 day^-1). However, under non-methanogenic conditions, gelatine hydrolysis was inhibited by 64% when a spectrum of VFA was added at a VFA/Gel (COD) ratio of 5.9. This was not caused by the ionic strength exerted by VFA but by the VFA itself. These results imply that methanogenesis dictates the reactor design for methane production but hydrolysis does for VFA production from wastewater proteins.

Protein hydrolysis and fermentation under methanogenic and acidifying conditions

BACKGROUND

Many kinds of wastewaters contain appreciable quantities of protein. Anaerobic processes are suitable for the treatment of wastewater high in organics to achieve pollution control and recovery of energy as methane and hydrogen, or intermediates for production of biofuels and valuable biochemicals. A distinction between protein hydrolysis and amino acid fermentation, especially for dissolved proteins, is needed to target which one is truly rate-limiting and to effectively harvest bioproducts during anaerobic conversion of these wastewaters. This study explored mesophilic anaerobic hydrolysis and amino acid fermentation of gelatine, as a model for dissolved proteins, at pH 7 and at pH 5.

RESULTS

The results showed that at pH 7, protein hydrolysis (first-order rate of 0.15 h^-1) was approximately 5 times faster than acidification of the hydrolysis products (first-order rate of 0.03 h^-1), implying that not hydrolysis but acidification was the rate-limiting step in anaerobic dissolved protein degradation. This was confirmed by (temporary) accumulation of amino acids. Nineteen different amino acids were detected during the first 8 incubation hours of gelatine at neutral pH and the total chemical oxygen demand (COD) of these 19 amino acids was up to approximately 40% of the COD of the gelatine that was added. Protein hydrolysis at pH 5 was 2-25 times slower than at pH 7. Shifting the initial pH from neutral to acidic conditions (pH 5) inhibited protein degradation and changed the volatile fatty acids (VFA) product profile. Furthermore, the presence or absence of methanogenic activity did not affect the rates of protein hydrolysis and acidification.

CONCLUSIONS

The findings in this study can help to set a suitable solid retention time to accomplish anaerobic degradation of protein-rich wastewaters in continuous reactor systems. For example, if the target is harvesting VFAs, methanogens can be washed-out for a shorter retention time while amino acid fermentation, instead of hydrolysis as assumed previously, will govern the design and solutions to improve the system dealing with dissolved proteins.

Physical activity during pregnancy is associated with a lower prevalence of gestational diabetes mellitus in Vietnam

AIMS

To assess the association between physical activity (PA) during pregnancy and the prevalence of gestational diabetes mellitus (GDM) accounting for sitting time.

METHODS

The study used data from a cohort study of 2030 pregnant women in Vietnam. Women were recruited from six hospitals in Ha Noi, Hai Phong, and Ho Chi Minh City. Baseline measurements including PA and GDM were taken at 24-28 weeks of gestation. PA was assessed during the past 3 months before the interview using the interviewer-administered Pregnancy Physical Activity Questionnaire. GDM was diagnosed at 24-28 weeks of gestation using the 2013 World Health Organization criteria.

RESULTS

1987 out of 2030 pregnant women were included in the final analysis, of which 432 had GDM (21.7%). Women undertaking the highest level (upper tertile) of PA during pregnancy appeared to have a lower risk of GDM [odds ratio (OR) 0.70, 95% confidence interval (CI) 0.53-0.94, P_trend 0.017] when compared to those at the lowest tertile of PA. Similarly, women with increased levels of moderate-intensive activity and household/caregiving activity during pregnancy were associated with reduced risks of GDM (OR 0.66, 95% CI 0.50-0.86, P_trend 0.002 and OR 0.72, 95% CI 0.55-0.95, P_trend 0.020, respectively). These apparent inverse associations were not attenuated by their sitting time. There were no significant associations between sitting time, light-intensity activity, vigorous-intensity activity, occupation, sports/exercise, commuting, or meeting exercise guidelines and GDM risk.

CONCLUSIONS

High levels of PA, particularly moderate-intensity and household/caregiving activities during pregnancy were associated with a lower prevalence of GDM independent of sitting time.

Evaluation of the integrated clinic model for HIV/AIDS services in Ho Chi Minh City, Viet Nam, 2013-2014

Setting: Ho Chi Minh City (HCMC), Viet Nam. Objective: To evaluate a new integrated service model for human immunodeficiency virus/acquired immune-deficiency syndrome (HIV/AIDS) care. Design: In HCMC, co-located services, including voluntary HIV counseling and testing (VCT), HIV treatment at out-patient clinics (OPC), and methadone maintenance therapy (MMT) for persons who inject drugs, have operated under different administrative structures. In the context of decreasing international financial support, integration of these services into one administrative structure with reduced staff occurred in seven districts in HCMC between October 2013 and June 2014. We used a pre-post study design to compare service-related outcomes from routinely collected data at health facilities 6 months before and 6 months after integration. Results: The proportion of HIV-infected persons linked from VCT to OPCs was unchanged or increased following integration. A higher percentage of patients eligible for antiretroviral therapy (ART) were started on ART. The proportion of ART patients lost to follow-up remained unchanged. The proportions of MMT patients who tested positive for heroin or other substances decreased or were unchanged. Conclusions: VCT, OPC and MMT service delivery quality remained the same or improved during the 6 months following the integration. Expansion of the integrated model should be considered for HIV-related services.

Enhanced biomethanation of kitchen waste by different pre-treatments

Five different pre-treatments were investigated to enhance the solubilisation and anaerobic biodegradability of kitchen waste (KW) in thermophilic batch and continuous tests. In the batch solubilisation tests, the highest and the lowest solubilisation efficiency were achieved with the thermo-acid and the pressure-depressure pre-treatments, respectively. However, in the batch biodegradability tests, the highest cumulative biogas production was obtained with the pressure-depressure method. In the continuous tests, the best performance in terms of an acceptable biogas production efficiency of 60% and stable in-reactor CODs and VFA concentrations corresponded to the pressure-depressure reactor, followed by freeze-thaw, acid, thermo-acid, thermo and control. The maximum OLR (5 g COD L(-1) d(-1)) applied in the pressure-depressure and freeze-thaw reactors almost doubled the control reactor. From the overall analysis, the freeze-thaw pre-treatment was the most profitable process with a net potential profit of around 11.5 € ton(-1) KW.

[Antiparasitic treatments in pregnant women and in children in 2003]

Like antibacterial agents, antiparasite drugs for pregnant women and children must be chosen in function of the stage of pregnancy, age of the child, and expected benefit-risk ratio. While no agent is totally safe, there are few absolute contraindications. Most zones of serious endemic parasite disease are located in developing countries where parasite, bacterial, or viral conditions combined with poor nutrition treatment make it necessary to treat disease in a complex pathogenic environment that weakens pregnant women and children with multiple parasite infections. In both temperate and tropical zones, there have been few real therapeutic advances involving release of new products on the market or development of new indications for existing products. Constant appearance and extension of hematozoa resistance to conventional and even more recent antimalarial agents have prompted research to find new active drugs and long-lasting treatment combinations. Real therapeutic breakthroughs have resulted from the need to develop safe drugs without substantial side-effects for single-dose use in control programs against endemic parasite diseases in mass populations including pregnant women and young children in tropical zones. There are several notable examples in the field of major verminous diseases. Ivermectin is a versatile drug that can be used against filariasis as well as for management of intestinal worms or ectoparasitosis in temperate and tropical countries. Praziquantel is an important advance in platyhelminthiasis, especially bilharziais. Triclabendazole, the latest addition to the benzimidazole family, has shown promise as a substitute for bithionol, that is difficult to procure and not recommended in pregnant women, for treatment distomiasis occurring in pregnant women and children. Other examples include albendazole against giardiasis, nitazoxamide against cryptosporidiosis, artemisinine against bilharziasis, and paramomycine, not recommended in pregnant women, against leishmaniasis.

A comparison of urinary incontinence among African American, Asian, Hispanic, and white women

OBJECTIVE

This study was undertaken to compare urodynamic findings and the rate of incontinence diagnoses among various ethnic groups.

STUDY DESIGN

Data were collected for all new patients referred to the urogynecology clinic during a 10-year period. One hundred ninety-five Hispanic, 95 white, 66 Asian, and 59 African American women had urodynamic testing and were included in the study. All women had a complete history, physical examination, and multichannel urodynamic studies. Demographic data, urodynamic data, and final diagnoses differences were analyzed.

RESULTS

African American women had higher maximum urethral closure pressures than Hispanic, white, or Asian women (58 cm H2O vs 47, 47, and 48 cm H2O; P =.001, P =.005, and P =.02). African American women were less likely to be diagnosed with genuine stress incontinence than were Hispanic or white women (42% vs 67% and 59%; P <.001 and P =.046). Detrusor instability was diagnosed more often in African American women than in Hispanic, white, or Asian women (29% vs 8%, 15%, and 14%; P <.001, P =.04, and P =.04).

CONCLUSIONS

African American women with urinary incontinence have different urodynamic diagnoses than Hispanic, white, or Asian women. Hispanic, white, and Asian women have similar rates of genuine stress incontinence. Although African American women have lower rates of genuine stress incontinence than Hispanic and white women, they have higher rates of detrusor instability than all 3 groups.

The role of DNA-protein salt bridges in molecular recognition: a model study

A theoretical study is presented of the influence of salt bridges between cationic side chains and DNA phosphates on DNA conformation and flexibility. The DNA sequence studied is that of the catabolite activator protein binding oligomer from the crystallized complex. The effect of salt bridges is modeled by neutralization of net phosphate charges for the groups involved in such interactions in the crystallized complex. Energy-optimized conformations are obtained by molecular mechanics using the JUMNA program. Base sequence dependence is studied by moving the phosphate neutralization pattern along the sequence and also by point mutations. Normal mode analysis is used to evaluate DNA flexibility. The results obtained show that the free oligomer is already precurved in the direction favored by the protein, and the effect of phosphate neutralization is principally to increase this curvature. This effect is, however, strongly sequence dependent. In addition, it is shown that oligomer flexibility cannot be explained by a simple superposition of the properties of successive dinucleotide steps, strong long-range coupling effects are observed. In all the cases examined, phosphate neutralization, however, leads to a reduction in oligomer flexibility.

Sequence specificity of bacteriophage 434 repressor-operator complexation

The binding affinity of the bacteriophage 434 repressor for its DNA operator depends strongly on the nature of two central base-pairs that are not in contact with the dimeric protein. In order to investigate the origin of this sequence specificity, we carried out molecular modelling of five model operators with central TA, AT, CG, GC and IC sequences. The five oligomers were studied both before and after complexation with the N-terminal binding domain of the 434 repressor. The relative importance of nucleic acid flexibility on operator-repressor binding was studied via a low frequency normal mode analysis using an internal coordinate method that we developed recently. The results suggest a higher twisting flexibility for TA and AT central steps than for CG, GC or IC steps, but the differences appear to be too small to account for the strength of repressor binding. An energetic analysis of the model operator-repressor complexes reveals rather that the preference for A.T and T.A base-pairs is electrostatic in origin and is linked to the presence of cationic Arg43 side-chains of repressor. This conclusion is supported by comparison with an R43A mutant and correlates with the sequence dependence of the electrostatic potential in the central minor groove of the operators.

Short- and long-term action of multiple doses of ivermectin on loiasis microfilaremia

One hundred nine Gabonese patients infected with Loa loa microfilariae were treated with ivermectin (200 microg/kg of body weight) at the Parasitology, Mycology and Tropical Medicine Department (Faculte de Medecine et des Sciences de la Sante, Libreville, Gabon). Each was given one dose per month for six consecutive months. The peripheral blood microfilaria (mf) count before and after each dose showed an average decrease in the microfilaremia of 87.3% (short-term-single dose). An annual single-dose mass treatment with 200 microg/kg of ivermectin was sufficient to control the parasite in populations with low (< 400/ml) L. loa mf counts. One month after the sixth dose (short-term-multiple doses), the average microfilaremia rate had decreased by 99.2% compared with the initial infection (35 patients). Samples were taken from 28 patients one month after the first dose and one month after the sixth dose. The average mf count decreased by 96.4% after the first dose and by 99.6% after the sixth dose (average residual mf counts = 13.7 and 1.5 mf/ml, respectively). The mf count after the sixth dose was only 11.2% of the count after the first dose. The low mf count persisted for more than six months after the sixth treatment (long-term-multiple doses). Thus, mass treatment with multiple doses is more appropriate for areas where the blood mf count is very high. These results show that the number of the annual treatments used in mass chemotherapy with ivermectin can be adapted to each population to provide efficient protection.

Light microscopic changes in Plasmodium falciparum from Gabonese children treated with artemether

The changes in Plasmodium falciparum in four Gabonese children suffering from severe malaria and treated with pure artemether were observed in thin blood smears fixed and stained with Giemsa and examined by light microscopy. Peripheral blood samples were taken every 8 hr up to 72 hr from three children and every 3 hr up to 9 hr from the other child. The morphologic changes involved all development stages (trophozoites, schizonts, and gametocytes); they were first seen 3 hr after the start of treatment and all parasites were abnormal after 24 hr. After two days of treatment, all infected erythrocytes disappeared except for a few with necrotic trophozoites. The morphologic changes were similar to the ultrastructural changes previously described in vivo and in vitro in experimental models. They confirm the rapid effect of artemisinin derivatives on parasite clearance and clinical recovery, particularly in cases of cerebral malaria.

[Aspects of malaria in the hospitalized child in Gabon]

To gain insight into the impact of malaria on children in terms of frequency and severity, a study was carried out in a department of the Owendo Children's Hospital in Libreville, Gabon, a fully endemic area. Diagnosis of Plasmodium falciparum malaria was confirmed by blood smears in 295 of the 1592 children admitted in 1992, i.e. 18.5% of admissions. Malaria was therefore the primary cause of hospitalization. Of 122 deaths observed during the study period 9 were due to malaria-associated complications for an overall mortality rate of 7.4% and malaria-related mortality rate of 3.1%. These rates are low in comparison with those reported by other departments in Central Africa. Convulsions were observed in 30.5% of children in the department and malaria was the underlying cause of convulsions in 62.9% of these cases. Severe anemia (< 5 g/dl) was noted in 23.7% of children overall and was associated with malaria in 54.7%. Severe malaria as defined by the criteria of the World Health Organization was observed in 33.2% of children. These findings illustrate the extent of the impact of endemic malaria on children in Gabon and emphasize the need to promote malaria control programs and improve treatment.

Reduced Loa loa microfilaria count ten to twelve months after a single dose of ivermectin

The action of a single dose of ivermectin (200 micrograms/kg) on 71 Gabonese patients with Loa loa microfilariae in the peripheral blood, and living in areas highly endemic for loiasis, has been evaluated. Ten to 12 months after treatment, 43 patients (63%) had no circulating microfilaria and the geometric mean peripheral blood microfilaria count had decreased by 88.6% (P < 0.02). Thus, a single annual dose of ivermectin can markedly reduce loiasis transmission.

[Cryopreservation of isolates of Toxoplasma gondii in cell culture]

For a better preservation and identification of Toxoplasma gondii isolates, we propose a new method of freezing of toxoplasma growth in THP-1 cell culture. A cystogenic strain isolated from foetal blood has been grown in these cells and frozen in liquid nitrogen. After thawing, toxoplasma recover the same growth rate and morphology in vitro and the same capacity to form brain cysts into mice compared to the initial strains. The freezing of the cell suspension provides a simple and appropriate method for preservation of Toxoplasma gondii within "bank" isolates.

[Chromoblastomycosis in Gabon. Study of 64 cases]

During the last 25 years, 64 cases of chromoblastomycosis were diagnosed in Gabon. They came from the entire territory, where living in rural zones men as well as women were affected. The evolution of the disease has lasted for more than 10 years for the majority of the cases. The preferential location is the lower limb for 78.5% of the patients, with a double localization for one case and an exceptional malignant transformation for another case. Two clinical aspects emerged, despite an apparent polymorphism: extensive patches and warty nodules, spread apart from or adjacent to the others. The histological images were classical and the fumagoid cells, sometimes budding and filamentous, were easily detected during examination of the squama and scabs. Fonsecaea pedrosoï was the only identified species. The 5-fluorocytosine treatment constantly led to an improvement of the lesions. The major problem for these destitute patients is economic, concerning the cost of the therapy.

[Digestive cryptosporidiosis in young children in an urban area in Gabon]

A 27 month epidemiological survey of cryptosporidiosis in stools was conducted in 288 Gabonese children aged between 0 and 2 years (mean 10.2 months). By at least one of two staining techniques, acid-fast and direct immunofluorescence, the rate of infection was determined to be 24%. The rate was 28% in cases of acute diarrhea, in striking contrast with the low prevalence of 14.8% in uninjured gastroenteritus subjects (p < 0.05). The notion of asymptomatic carriers was clearly demonstrated. The maximum of 34.4% was observed for infants aged between 6 and 12 months (p < 0.02). In cases of malnutrition, this rate increased to 31.8%, whereas it was 16.8% in eutrophic children (p < 0.01). For the rainy and dry seasons, it was 31.7% and 19.4%, respectively (p < 0.02). Water is emerging as an important vehicle for the transmission and spread of Cryptosporidium sp. in tropical areas.

[Lipid profile during specific malaria therapy in Gabonese children]

We report specific dyslipidemia in Gabonese children aged 18 months to 4 years old treated with Halfan for malaria. This is observed in addition to the hypoglycemia typically associated with malaria. C-HDL (high density lipoprotein) fell on day 0 (D0), then increased during the treatment. Triglycerides (TG), total cholesterol (TC) and non-esterified fatty acids (NEFA) rose on D0. CT continued to rise evenly throughout the treatment, whereas TG declined. The differences with respect to normal values are significantly different as assessed by the Student test. We report metabolic variation and tolerance to Halfan.

[Treatment of Plasmodium falciparum malaria attacks in children with artemether in Gabon]

The efficacy and tolerance of artemether administered intramuscularly twice daily (1.6 or 3.2 mg/kg/day) were evaluated in 47 children (mean age 2.4 years old) suffering from mild (n = 28) or severe (n = 19) attacks of Plasmodium falciparum malaria. Tolerance was also investigated in 5 additional children for whom the efficacy could not be assessed, because the parasitaemia was too low on inclusion. Antipyretics were systematically administered and therefore efficacy of the treatment was scored according to the decrease in the density of the parasite and the remission of severe symptoms in those patients with severe attacks. Parasites were eliminated in all patients in a mean of 47.7 +/- 9.8 hours. The time to eradication was not significantly affected by the dose, prior administration of an anti-malarial agents to treat the attack or the severity of the attack. There were two cases of clinical and parasitological regression, on days 14 and 21. There were no deaths. The neurological symptoms of severity resolved in 48 hours in most cases. Local and systemic tolerance was excellent.

Evaluation of Onchocerca volvulus-specific IgG4 subclass serology as an index of onchocerciasis transmission potential of three Gabonese villages

The major objective of this study was to evaluate the usefulness of IgG4 ELISA and Western blot analysis, using a crude extract of Onchocerca volvulus adult worms as antigens, for diagnosing onchocerciasis in a Gabonese paediatric population with mixed filarial infections. The subjects had loaisis, streptocercosis or mansonellosis in addition to onchocerciasis. Control sera from loaisis or mansonellosis subjects residing outside the endemic zone were used to provide the cut-off point for positive results. The IgG4 ELISA had a specificity of 96% but a lower sensitivity of 78.7%. It detected 25 onchocerciasis cases out of 65 individuals who were negative on parasitological examination. Furthermore, the ELISA provided a more accurate picture of onchocerciasis transmission in a village with very low skin microfilarial load. A 27.5-kD antigen was identified on Western blots as a marker of onchocerciasis. The paediatric population provided a reliable window for assessing the parasitologic and serologic parameters in the three villages with disparate levels of onchocerciasis transmission.

White piedra and Trichosporon species in equatorial Africa. III. Identification of Trichosporon species by slide agglutination test

Fifty-two Trichosporon strains isolated from Gabonese female patients 15-60 years, were studied. The identity of these strains was established by two different methods: the method proposed by Guého et al. (1992), based on mycological criteria, and a slide agglutination method performed with monospecific antisera prepared in our laboratory. The final results show a perfect correlation between the two methods, which allowed us to identify 25 strains of T. mucoides, 21 strains of T. inkin and seven strains of T. asahii. The results of the agglutination tests performed with 24-h-old subcultures grown on Sabouraud glucose agar are available in less than 15 mins. In the light of these results, it appears that this method, which is rapid and easy to perform and reproduce, may readily be used in hospital laboratories. In addition, this method allowed us to verify the presence of antigens common to the genera Cryptococcus and Trichosporon, which were easily shown by the use of crude sera. The fact that the anti-Trichosporon monospecific sera lose their capacity to agglutinate Cryptococcus neoformans proves their high specificity.

White piedra and Trichosporon species in equatorial Africa. I. History and clinical aspects: an analysis of 449 superficial inguinal specimens

White piedra is a hair infection characterized by nodules composed of fungal elements which envelop the hair shaft. Classically, this infection was considered to be produced by an asexual yeast-like fungus, Trichosporon beigelii. At present, in accordance with studies carried out previously, this species is subdivided into six newly defined distinct species (T. asahii, T. ovoides, T. inkin, T. mucoides, T. asteroides and T. cutaneum), all belonging to the class Basidiomycetes. Although widespread, white piedra has not previously been described in tropical regions of Africa. The present study, carried out in Libreville (Gabon), an equatorial region of Africa, shows that the incidence of this infection is quite high (18% of 449 inguinal specimens) in the female population aged 15-60 years, with a predominance in young patients (15-44 years). The relationship between the clinical manifestations and the specific hair lesions is also detailed. Three species belonging to the genus Trichosporon were identified: T. mucoides, T. asahii and T. inkin.

White piedra and Trichosporon species in equatorial Africa. II. Clinical and mycological associations: an analysis of 449 superficial inguinal specimens

Eighty-one of 449 Gabonese female patients examined were found to be positive for genitopubic white piedra. The association with trichobacteriosis is frequent (53 cases), and mostly seen with inguinal intertrigo. Fifty-two strains belonging to the genus Trichosporon were isolated from genital hairs as well as from inguinal intertrigo lesions. These strains were identified in accordance with previously defined morphological and biochemical criteria. Three species were recognized: T. mucoides (25 strains), T. inkin (20 strains) and T. asahii (seven strains). Their macroscopic and microscopic morphological properties, as well as their ability to reduce tetrazolium, were determined. In addition, the study of the clinical and pathogenic associations in which each of these strains was involved revealed some of their particular properties.

[Evaluation of 3 tests applied in the immunological diagnosis of hepatic amebiasis in Gabon]

The diagnosis of hepatic amoebiasis is not always easy. In case of suspicion of hepatic amoebiasis in an endemic area, the patient is immediately treated with a 5-nitroimidazole. Immunological diagnosis is indispensable. After a comparative study of BLA, IHA and IFA reactions, the BLA test has shown to be well adapted to the context of a country with insufficient sanitary infrastructure. The BLA test is easily performed and enables rapid detection of antibodies. The result obtained in about 5 minutes allows to adjust the therapeutic conduct.

Elevated antifilarial IgG4 antibody levels in microfilaremic and microfilaridermic Gabonese adults and children

Immunologic analyses of sera from 47 selected individuals living in a mixed filariasis transmission zone in Gabon were carried out. Onchocerca volvulus, Loa loa, Mansonella streptocerca, and M. perstans are transmitted in this region. Based on parasitologic findings and age, the 47 individuals were stratified into four groups: microfilaria negative (Mf-) children (3-15 years old), Mf- adults (> 15 years old), microfilaria positive (Mf+) children and Mf+ adults. For descriptive purposes, the term microfilaria positive refers to individuals with skin and blood microfilariae. Antifilarial antibody titers were determined using an enzyme-linked immunosorbent assay with Dipetalonema viteae antigens. In general, children had higher titers of IgG antibodies than adults. For the IgG1, IgG2, and IgG3 subclass responses, both age and microfilarial status appeared to be important variables since Mf- children consistently had the highest titers whereas Mf- adults had the lowest titers. For the IgG4 antifilarial response, only the microfilarial status was an important variable. All Mf+ individuals had significantly higher levels of IgG4 antibody than Mf- individuals. Pooled sera of Mf- and Mf+ individuals reacted with similar O. volvulus antigens on Western blots. Control sera of individuals who did not reside in the study area, but who had single infections with L. loa or M. perstans, did not react with any O. volvulus antigens.

[Bilharziasis caused by Schistosoma intercalatum, a recent and forgotten form of schistosomiasis]

Schistosoma intercalatum schistosomiasis is confined to the western regions of equatorial Africa. It is often asymptomatic but it produces microscopic lesions in the intestine (mainly the rectum), the liver and the genital organs of both men and women, the latter lesions being more insidious and insufficiently explored. Its treatment, like that of other schistosomiases, consists of one course of praziquantel. Naturally, S. intercalatum may be hybridized with S. haematobium in Gabon and Cameroun which are the two countries where the two parasites coexist.

[Seroepidemiological study of toxoplasmosis in Libreville, Gabon]

A sero-epidemiological survey of toxoplasmosis has been carried out in 1178 subjects residing in urban and suburban areas of Libreville, Gabon. Two techniques were used: Pastorex toxo of the Institut Pasteur and ISAGA of bioMérieux. The acquisition of antibodies occurs at an early age, from the age of six months on. After the age of 15 years, the age of procreation, the prevalence is 68%. Between the ages of 15 and 19 years, 19% have IgM. The risk for toxoplasmosis acquired during pregnancy is not to be neglected. It decreases between the ages of 20 and 30 years. The most probable source of contamination is the reservoir from the soil. No difference between the sexes was observed.

Successful treatment of acute fascioliasis with bithionol

Fascioliasis is the parasitic infestation of the liver and biliary tract related to Fasciola hepatica. Bithionol is proposed as the treatment of choice for human fascioliasis without major side effects. However, the efficacy of bithionol has been evaluated in chronic but not in acute fascioliasis. In this study we report on the success of treatment with bithionol in 10 patients with fascioliasis, 8 having acute fascioliasis. The criteria for the diagnosis of fascioliasis were hypereosinophilia, positive immunoelectrophoresis and indirect hemagglutination. Bithionol was given orally to hospitalized patients at the daily dose of 25 mg/kg body wt for 10 days. Three patients with acute fascioliasis received a second course of bithionol 2 or 3 mo after the first because of the recurrence of diarrhea and fatigue in one patient and persistent hypereosinophilia in two patients. All patients were cured. The follow-up period after the first course of treatment was between 16 and 47 mo. No major side effects were observed. We conclude that bithionol is the drug of choice for both acute and chronic fascioliasis. Moreover, its oral administration may allow treatment of fascioliasis in outpatients who do not have serious symptoms.

[Anti-nuclear factor and anti-toxoplasma antibodies detected using the Toxo-M Abbott kit]

The antibody capture IgM Toxo Abbott is a specific method. But serum specimens had false positive results. These serum specimens have been studied. There was no Forssman antibodies, no rheumatoid factors. The IgM level was normal but for some of them there were antinuclear antibodies and natural agglutinins. To interfare the assay, the antinuclear antibodies have to be IgM.

Alzheimer's disease as a capillary dementia

In addition to the well known structural stigmata which accompany the senile dementia of Alzheimer, attention is called to the presence of a group of robust changes which affect the fine vessels (capillaries, capillary arterioles and capillary venules), particularly of the cerebral cortex. These alterations include irregular pouches and excrescences on the vessels (a "lumpy-bumby" appearance), general thickening of the basement membrane, loss of the fine perivascular neuronal plexus which seems to invest each vessel, no matter how small, and the appearance of pits or lacunae in the vessel walls of about one half of the Alzheimer patients studied. None of these changes have been seen in a group of approximately age-matched, non-demented controls. Much of this perivascular neural plexus originates within a few specific subcortical fields, especially the locus ceruleus and the nucleus basalis of Meynert and basal forebrain area. These also happen to be included among those brain areas which experience the most marked neuronal atrophy or loss in Alzheimer's disease. Since there is some evidence suggesting that surgically induced vascular denervation in myocardium produces dramatic changes in vascular wall structure we wonder whether neuronal pathology developing initially in these subcortical areas may not play a significant role in the development of the characteristic neuropathology in Alzheimer's disease. These speculations emphasize the possible importance of a failing blood brain barrier in the development of the disease.

[Treatment of bilharziasis due to Schistosoma mekongi with praziquantel]

After a review of the mechanisms of anti-schistosomal activity of praziquantel and the treatment of Schistosoma mekongi with this drug, the authors report two cases of Schistosoma mekongi treated with praziquantel with failure. Rectal mucosa biopsies are performed and eggs are present. Light microscopic, electron microscopic and on ultra-thin sections examination of these samples don't reveal morphological alterations of Schistosoma mekongi eggs after treatment.

[Schistosoma mekongi bilharziasis along the Mekong River and its affluents, the Mun and Tonle Sap Rivers. General review]

First cases of Schistosomiasis in the South East Asian were described 30 years ago but the existence of a particular species in this area: Schistosoma mekongi has been discussed for a long time. During the last few years, emigration of Laotian and Cambodian people allowed a better knowledge of this affection. Through recent literature the authors make a restatement of the epidemiology, biology and treatment of this disease.

[A new molecule in antiparasitic therapy: alpha-difluoromethylornithine]

Alpha-difluoromethylornithine (DFMO) is a specific irreversible inhibitor of ornithine-decarboxylase (ODC), key enzyme in the biosynthesis of polyamines, physiological compounds involved in cell multiplication. Pharmacokinetic studies of the drug revealed good oral absorption, low metabolisation and mainly urinary excretion. Short half-life (3 hrs to 3 hrs 30) implicates daily repeated administrations. DFMO is well tolerated, side effects being reversible on discontinuing drug therapy. They chiefly include diarrheas, hematological perturbations (thrombocytopenia) and hear losses (high dosages). Experimental studies show best results on trypanosomes: curative action in mice infected with Trypanosoma brucei brucei. DFMO is effective too against infection with sporozoïtes of Plasmodium berghei. Early clinical observations in African patients with Trypanosoma brucei gambiense sleeping sickness show favorable results: efficacy in both stages of the disease, without significant toxicity. Further trials are required to define optimal therapeutic applications. By the way, DFMO already seems to be a promising alternative to conventional therapy of African trypanosomiasis, expecting other indications in the field of antiparasitic chemotherapy.

[Serological study of toxoplasmosis and echinococcosis in cattle breeders and abattoir personnel in Benin]

In Benin, a serological study of toxoplasmosis and hydatid disease has been effected among bovine stock-breeders and the staff of the slaughter-houses in comparison with a sample of blood donors. Our results reveal the highest rate of toxoplasmosis infection (87%) among the staff of the slaughter-houses, whereas the bovine stock-breeders are the most exposed population to hydatid disease with a 9% prevalence. There is no mention of similar works in Benin in medical literature.

Denervation microangiopathy in senile dementia, Alzheimer type

Structural analysis of the capillary plexus in the brains of 5 patients with clinical and neuropathological diagnosis of Senile Dementia, Alzheimer Type, revealed a group of striking physical alterations compared with tissue specimens from 5 age-matched controls. Capillary walls were thickened with irregular lumpy, nodulated contours which appeared due, in part, to infiltration of the vascular wall with rounded cell-like bodies. In some cases, these resembled the perikarya of pericytes or monocytes, or their protoplasmic extensions, which were often filled with lipids. In each case, there was no trace of the perivascular neural plexus which regularly invests the microvasculature of the brain parenchyma. The loss of this neural plexus, believed to originate largely from locus ceruleus and the basal forebrain, may be related to the changes in capillary wall structure, and these, in turn, may lead to profound alterations in blood-brain barrier function. We suggest that this subcortically induced denervation microangiopathy may serve as a pathogenic factor in the development of SDAT.

[Irregular anti-P1 allo-antibodies and sinensis clonorchiasis]

A parasitological and immuno-hematological study was undertaken simultaneously in fifty South-East asian refugees at the time of their arrival in France. --in this series the frequency of individuals having a P2 erythrocyte phenotype is 80%. --54 % of these immigrants were found to be carriers of Clonorchis sinensis, a parasite rarely found in Europe. --in 40,7 % of these subjects infested by Clonorchis sinensis, the following properties were disclosed concerning the P1 allo-antibody: slow-P1 red cell agglutination at 22 degrees C, no hemolysis of P1 red cells in vitro, IgM antibody, in weak titers. The immuno-hematological study of the immuno-serums with respect to distomian antigens coupled with adsorption-elution using P1+++ red cells shows a close immunological relationship between the antibody of parasite origin and the anti-P1 allo-antibody.

[Experimental Schistosoma mansoni parasitosis in golden hamsters. Effects on the intensity of parasitism, and on the rate of antibodies' circulation, after administration of estrogen, testosterone, or progesterone (author's transl)]

A reduction in the intensity of parasitism under the effect of an implantation of 20 mg of estradiol is observed again but such result is also obtained with testostérone administered in the same way and at the same dose. On the other hand, no significant variation in the number of parasites was observed in animals having received an implantation of 20 mg of progesterone. However, serological examinations showed that the animals treated with one of these hormones all have a specific antibody level higher than the untreated control group. Finally, it is impossible to establish a relationship between level of serum antibodies and the number of parasites.

[About eosinophilic infiltration in cellular tissue (author's transl)]

With this paper, we want to settle the part of eosinophilia in the definition of diseases as entities. Consequently, we emphasize the contribution of eosinophils in the histological diagnosis. Eosinophilic infiltration is the main marker of several lesions. We review successively some of these entities. They belong to tumoral or inflammatory (without or with vasculitis) pathology. The function of eosinophils must improve our knowledge about the significance of all these lesions (parasitic infestation, hypersensitivity...). These physiopathological mechanisms must be helpful to draw some new borders between these different entities.

[A parasitologic survey conducted in Touraine (France) in a group of South East Asia refugees (author's transl)]

Forty refugees (23 from 5 lao families and 17 from 3 cambodian families) previously and routinely treated against intestinal parasites, underwent stools and serum controls: 77 p. 100 had still intestinal parasites but 61 p. 100 had a normal blood cells count without hypereosinophilia. The parasites so detected were: Clonorchis sinensis, Heterophyes heterophyes, Trichuris trichiura, Necator americanus, Strongyloides stercoralis, Giardia intestinals and Entamoeba coli.

[Transfusional malaria. Another case (author's transl)]

Transfusional malaria is an unusual disease. Any fever, happening immediately after blood transfusions must evoke this diagnosis, confirmed by parasites detection in the blood. The treatment is rapidly efficacious. The prophylaxis is at the present time insufficient and would require fluorescent antibody test generalization.