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PubMed2004

Crimean-Congo hemorrhagic fever in Sistan and Baluchestan Province of Iran, a case-control study on epidemiological characteristics.

OBJECTIVES: Several cases of Crimean-Congo hemorrhagic fever (CCHF), an arboviral disease, have been reported since summer 1999 in different areas of Iran. The main objectives of this research were to determine the most important means and patterns of transmission and the epidemiologic characteristics of this disease. DESIGN: In this population-based case-control study, 24 patients from Zabol and Zahedan Districts in the Sistan and Baluchestan province, reported to the Center for Disease Control of Iran, were compared with 300 controls. The controls were sampled through the 'probability proportional to size cluster sampling' method from the general population of the same districts. The following variables were checked: age, sex, living environment (rural versus urban), education years, job, past history of tick bite, contact history with livestock, history of livestock slaughtering, presence of a designated place for animals at home, history of keeping livestock in the house. RESULTS: Variables which increased the chance of disease include: history of slaughtering (OR = 7.57, CI: 2.21-25.91), high-risk occupations (OR = 4.97, CI: 0.97-25.43), history of tick bite (OR = 105.89, CI: 9.32-1202.44), age above 40 years (OR = 7.32, CI: 1.06-50.26). CONCLUSION: The results of this study confirm that the scheme of risk factors and risk groups for Crimean-Congo hemorrhagic fever (CCHF) in Iran do not differ substantially from the other parts of the world. Even though tick bite is one of the most important risk factors for CCHF, it cannot explain all cases and there are other important risk factors such as high-risk occupations and having contact with livestock. Even taking care of livestock for a short period at home can increase the chance of contracting CCHF.

Adolescent↗
PubMed2004

Azadirachta indica leaf powder as an effective biosorbent for dyes: a case study with aqueous Congo Red solutions.

In the present work, the leaves of Azadirachta indica (locally known as the Neem tree) in the form of a powder were investigated as a biosorbent of dyes taking aqueous Congo Red solution as a model system. The sorbent was made from mature Neem leaves and was investigated in a batch reactor under variable system parameters such as concentration of the aqueous dye solution, agitation time, adsorbent amount, pH, and temperature. An amount of 0.6 g of the Neem leaf powder (NLP) per litre could remove 52.0-99.0% of the dye from an aqueous solution of concentration 2.87 x 10(-2) mmol l(-1) with the agitation time increasing from 60 to 300 min. The interactions were tested with respect to both pseudo first-order and second-order reaction kinetics; the latter was found to be more suitable. Considerable intra-particle diffusion was found to occur simultaneously. The sorption process was in conformity with Langmuir and Freundlich isotherms yielding values of the adsorption coefficients in the following ranges: Freundlich n: 0.12-0.19, Kf: 0.1039-0.2648 L g(-1); Langmuir qm: 41.24-128.26 g kg(-1), b: 443.3-1898.0 l mmol(-1), which supported favourable adsorption. The Langmuir monolayer capacity (qm) was high and the values of the coefficient b indicated the equilibrium, dye + NLP = dye...NLP being shifted overwhelmingly towards adsorption. Thermodynamically, the sorption process was exothermic with an average heat of adsorption of -12.75 kJ mol(-1). The spontaneity of the sorption process was also confirmed by the favourable values of Gibbs energy (mean values: -1.09 to -1.81 kJ mol(-1)) and entropy of adsorption (range: -18.97 to -56.32 J mol(-1)K(-1)). The results point to the effectiveness of the Neem leaf powder as a biosorbent for removing dyes like Congo Red from water.

Adsorption↗
PubMed2004

In vitro antiplasmodial activity of extracts and fractions from seven medicinal plants used in the Democratic Republic of Congo.

The in vitro antiplasmodial activity of seven EtOH extracts and twenty fractions from the partition of the initial ethanolic extracts from seven African medicinal plants used in the Democratic Republic of Congo (DR Congo) for the treatment of malaria was evaluated. The most active EtOH extracts (IC50 < 3 microg/ml) were those from Cassia occidentalis leaves, Euphorbia hirta whole plant, Garcinia kola stem bark and Phyllanthus niruri whole plant. Their respective petroleum ether soluble fractions also exhibited an antiplasmodial activity with IC50 < 3 microg/ml. EtOH extracts from Vernonia amygdalina leaves (5 < IC50 < 10 microg/ml), Tetracera poggei leaves (10 < IC50 < 50 microg/ml) and Morinda morindoides leaves (50 < IC50 < 100 microg/ml) were less active, but their petroleum ether fractions exhibited a pronounced antiplasmodial activity (IC50 < 3 microg/ml). The same observation could also be made for the petroleum ether fraction from Cassia occidentalis, Euphorbia hirta, Garcinia kola and Phyllanthus niruri. Isoamyl alcohol fractions from Euphorbia hirta, Phyllanthus niruri and Vernonia amygdalina showed IC50) values less than 3 microg/ml, and from Cassia occidentalis, Garcinia kola, Morinda morindoides and Tetracera poggei between 10 and 50 microg/ml. The observed antiplasmodial activity may be related to the presence of terpenes, steroids, coumarins, flavonoids, phenolic acids, lignans, xanthones and anthraquinones.

Animals↗
PubMed2006

Removal of congo red using activated carbon and its regeneration.

Activated carbon is used for the removal of colored toxic congo red dye. The effects of different operating conditions like, initial dye concentration, contact time, pH and temperature are studied for adsorption of congo red by a known amount of activated carbon (1.0g/L) under stirred batch condition. The zero point of charge of the activated carbon is found about 6.6. About 90% dye is removed for initial concentration of 50 and 100mg/L, it is about 80% at pH 7.0. Maximum adsorption (about 100%) of dye is observed at pH 2.0 for the concentration range studied here. Freundlich isotherm is found to fit the equilibrium data more adequately. Pseudo second order kinetic model explain successfully the kinetic data. The surfactant enhanced carbon regeneration (SECR) technique using both cationic and anionic surfactants is adopted for the regeneration of spent carbon by desorbing the dye. A kinetic model for dye desorption from the commercial activated carbon (CAC) is also proposed. Anionic surfactants show better performance than the cationic ones. Efficiency of dye desorption using surfactants is also compared with the desorption using pH change.

Adsorption↗
PubMed2004

The basic reproductive number of Ebola and the effects of public health measures: the cases of Congo and Uganda.

Despite improved control measures, Ebola remains a serious public health risk in African regions where recurrent outbreaks have been observed since the initial epidemic in 1976. Using epidemic modeling and data from two well-documented Ebola outbreaks (Congo 1995 and Uganda 2000), we estimate the number of secondary cases generated by an index case in the absence of control interventions R0. Our estimate of R0 is 1.83 (SD 0.06) for Congo (1995) and 1.34 (SD 0.03) for Uganda (2000). We model the course of the outbreaks via an SEIR (susceptible-exposed-infectious-removed) epidemic model that includes a smooth transition in the transmission rate after control interventions are put in place. We perform an uncertainty analysis of the basic reproductive number R0 to quantify its sensitivity to other disease-related parameters. We also analyse the sensitivity of the final epidemic size to the time interventions begin and provide a distribution for the final epidemic size. The control measures implemented during these two outbreaks (including education and contact tracing followed by quarantine) reduce the final epidemic size by a factor of 2 relative the final size with a 2-week delay in their implementation.

Congo↗
PubMed2005

Novel one-step real-time RT-PCR assay for rapid and specific diagnosis of Crimean-Congo hemorrhagic fever encountered in the Balkans.

Early and accurate diagnosis of Crimean-Congo hemorrhagic fever (CCHF) is essential for the treatment and outcome of the disease and prevention of its further transmission. Molecular-based diagnostic assays now serve as the front-line tool in the diagnosis of CCHF. However, the development of real-time RT-PCR assay for the detection of Crimean-Congo hemorrhagic fever virus (CCHFV) has been hampered by a virus strain variation. The development of a one-step real-time RT-PCR assay for the detection of CCHFV is described herein. The technique is based on the fluorescence resonance energy transfer probe technology employing the endonuclease activity of Taq polymerase enzyme. The assay was designed to detect specifically the strains from a phylogenetic cluster of CCHFV which encompasses the known CCHFV strains circulating in the Balkan region. The detection system was tested using CCHFV strain Kosovo Hoti, clinical serum samples and ticks. The real-time assay described is rapid, specific and sensitive. Since the Balkan peninsula is also an endemic region for hemorrhagic fever with renal syndrome (HFRS), this method is suggested as convenient for early differential diagnosis of suspected viral hemorrhagic fever patients.

Animals↗
PubMed2006

HIV-1 subtypes and recombinants in the Republic of Congo.

To document the actual genetic diversity of HIV-1 strains in the Republic of Congo, 114 HIV-1 positives persons were sampled in 2003 and 2004 after their informed consent. They were attending the teaching hospital, the reference health center in Makelekele, Brazzaville and the regional hospital centers in Pointe-Noire, Gamboma and Ouesso. A total of 104 samples were genetically characterized by direct sequencing of the p24 gag region and 80 were also subtyped in the V3-V5 env region. The genetic subtype distribution of the Congolese strains showed the predominance of subtype A (36.5% and 32.5% in gag and env, respectively) and G (30.8% and 21.25%), whereas subtype D strains represented 12.5% and 15%. Subtypes C, F, H, J, K and the CRFs-01, -02, -05 -06, and also the recently characterized CRF18 were seen at lower rates. Finally, 4.8% (gag) and 6.25% (env) of the strains could not be classified. Moreover, a high intra-subtype diversity was observed in our study. Among 70 strains which have been characterized in the two genomic regions, 14 (20%) appeared to be unique recombinants. These data show a high genetic variability in the Republic of Congo, where all the subtypes have been documented together with certain subsubtypes and several CRFs.

Congo↗
PubMed1987

Can the use of an endoscopic Congo red test decrease the incidence of incomplete proximal gastric vagotomy?

The endoscopic Congo red test allows accurate and rapid evaluation of the completeness of vagotomy and may result in a lower incidence of postoperative incomplete vagotomy. This report describes 44 patients tested during proximal gastric vagotomy. Evidence of incomplete vagotomy was found in over 95% at the conclusion of the conventional operation. Importantly, the test was a guide to further operative maneuvers which abolished the evidence of incomplete vagotomy upon subsequent testing. The endoscopic Congo red test satisfies the requirements for an ideal test for complete vagotomy: it is easily performed, does not require special equipment, and can be repeated several times if necessary to verify that desired effects have been achieved. The wider use of this test, therefore, appears justified.

Congo Red↗
PubMed1998

Chrysamine-G, a lipophilic analogue of Congo red, inhibits A beta-induced toxicity in PC12 cells.

Increasing evidence suggests that deposition of amyloid-beta (A beta) peptide leads to neurodegeneration in Alzheimer's disease. Congo red, a histologic dye that binds to amyloid has previously been shown to diminish the toxic effects of A beta in cell culture. Since Congo red is too highly charged to enter the brain in significant quantities, a lipophilic derivative, Chrysamine-G, was tested for the ability to attenuate A beta[25-35]-induced toxicity in PC12 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Chrysamine-G showed a concentration-dependent inhibition of A beta[25-35]-induced toxicity. This protective effect became significant at 0.2 microM, a concentration very close to the Ki for Chrysamine-G binding to synthetic A beta (0.37 microM). A decarboxy derivative of Chrysamine-G, which does not bind to A beta, also did not protect against A beta-induced toxicity. The protective effects of Chrysamine-G may relate to its ability to bind directly to A beta and may involve other post-binding effects as well.

Alzheimer Disease↗
PubMed2006

Mortality in the Democratic Republic of Congo: a nationwide survey.

BACKGROUND: Commencing in 1998, the war in the Democratic Republic of Congo has been a humanitarian disaster, but has drawn little response from the international community. To document rates and trends in mortality and provide recommendations for political and humanitarian interventions, we did a nationwide mortality survey during April-July, 2004. METHODS: We used a stratified three-stage, household-based cluster sampling technique. Of 511 health zones, 49 were excluded because of insecurity, and four were purposely selected to allow historical comparisons. From the remainder, probability of selection was proportional to population size. Geographical distribution and size of cluster determined how households were selected: systematic random or classic proximity sampling. Heads of households were asked about all deaths of household members during January, 2003, to April, 2004. FINDINGS: 19,500 households were visited. The national crude mortality rate of 2.1 deaths per 1000 per month (95% CI 1.6-2.6) was 40% higher than the sub-Saharan regional level (1.5), corresponding to 600,000 more deaths than would be expected during the recall period and 38,000 excess deaths per month. Total death toll from the conflict (1998-2004) was estimated to be 3.9 million. Mortality rate was higher in unstable eastern provinces, showing the effect of insecurity. Most deaths were from easily preventable and treatable illnesses rather than violence. Regression analysis suggested that if the effects of violence were removed, all-cause mortality could fall to almost normal rates. INTERPRETATION: The conflict in the Democratic Republic of Congo remains the world's deadliest humanitarian crisis. To save lives, improvements in security and increased humanitarian assistance are urgently needed.

Cause of Death↗
PubMed1987

Congo red-negative amyloidosis-like glomerulopathy: report of a case.

An elderly patient who had nephrotic syndrome for many years was found to have mesangial expansion and thickening of the glomerular capillary basement membranes (GBMs) on light microscopy. Electron microscopy (EM) showed tubular structures measuring 24 to 27 nm in the mesangium and the subepithelial areas. Congo red staining for amyloid was negative. This case represents another instance of congo red-negative amyloidosis-like glomerulopathy.

Aged↗
PubMed1992

A study of phenotypic variation of Staphylococcus epidermidis using Congo red agar.

This study examines a series of phenotypic variants of Staphylococcus epidermidis that were generated from a pair of parent variants, isolated from valvular tissue of a patient with prosthetic valve endocarditis. The variants were initially classified by examining their colonial morphology on Congo red agar. In addition to differences in Congo red binding and colonial morphology, they differed in the expression of several surface components and enzymes. Despite these phenotypic differences, all variants had the same restriction endonuclease profile of plasmid DNA. Examination of a collection of clinical isolates demonstrated that phenotypic variation is a common property of S. epidermidis. The ability to express different combinations of surface components and enzymes could contribute to the virulence of S. epidermidis strains by enabling these organisms to colonize a range of diverse environments.

Agar↗
PubMed1998

Oligomerization of endogenous and synthetic amyloid beta-protein at nanomolar levels in cell culture and stabilization of monomer by Congo red.

Amyloid beta-proteins (A beta) are proteolytic fragments of the beta-amyloid precursor protein (beta APP) that are secreted by mammalian cells throughout life but also accumulate progressively as insoluble cerebral aggregates in Alzheimer's disease (AD). Because mounting evidence indicates that A beta aggregation and deposition are early, critical features of AD leading to neurotoxicity, many studies of A beta aggregation have been conducted using synthetic peptides under generally nonphysiological conditions and concentrations. We recently described the oligomerization of A beta peptides secreted by beta APP-expressing cells at low nanomolar (20-30 ng/mL) levels into sodium dodecyl sulfate- (SDS-) stable oligomers of 6-16 kDa. Here, we extensively characterize this in vitro system and show that the amyloid binding dye, Congo red, acts to markedly decrease oligomer/monomer ratios by stabilizing the 4 kDa A beta monomers (ID50 approximately equal to 3.4 microM). Addition of radioiodinated synthetic A beta 1-40 to the cultures or to their conditioned media at physiological concentrations (0.25-2.5 nM) reveals that it undergoes progressive aggregation into SDS-stable oligomers of 6-25 kDa during brief (approximately 4 h) incubation at 37 degrees C, and this is inhibitable by Congo red. The level of A beta oligomers can be quantitated in the Chinese hamster ovary (CHO) conditioned medium by size-exclusion chromatography as well as by SDS-polyacrylamide gel electrophoresis (PAGE), and comparison of these two methods suggests that aggregation of A beta into higher molecular weight polymers that are not detectable by SDS-PAGE occurs in the cultures. We conclude that both endogenous and synthetic A beta can assemble into stable oligomers at physiological concentrations in cell culture, providing a manipulable system for studying the mechanism of early A beta aggregation and identifying inhibitors thereof under biologically relevant conditions.

Amyloid beta-Peptides↗
PubMed1998

Congo red inhibits proteoglycan and serum amyloid P binding to amyloid beta fibrils.

Various data suggest that Alzheimer's disease results from the accumulation of amyloid beta (A beta) peptide fibrils and the consequent formation of senile plaques in the cognitive regions of the brain. One approach to lowering senile plaque burden in Alzheimer's disease brain is to identify compounds that will increase the degradation of existing amyloid fibrils. Previous studies have shown that proteoglycans and serum amyloid P (SAP), molecules that localize to senile plaques, bind to A beta fibrils and protect the amyloid peptide from proteolytic breakdown. Therefore, molecules that prevent the binding of SAP and/or proteoglycans to fibrillar A beta might increase plaque degradation and prove useful in the treatment of Alzheimer's disease. The nature of SAP and proteoglycan binding to A beta is defined further in the present study. SAP binds to both fibrillar and nonfibrillar forms of A beta. However, only the former is rendered resistant to proteolysis after SAP association. It is interesting that both SAP and proteoglycan binding to A beta fibrils can be inhibited by glycosaminoglycans and Congo red. Unexpectedly, Congo red protects fibrillar A beta from breakdown, suggesting that this compound and other structurally related molecules are unlikely to be suitable for use in the treatment of Alzheimer's disease.

Amyloid beta-Peptides↗
PubMed2001

Phenotype evaluation of Bordetella bronchiseptica cultures by urease activity and Congo red affinity.

AIMS: The present study shows that Congo red binding and urease activity assays are useful for selection of virulent (Bvg+) Bordetella bronchiseptica cultures. METHODS AND RESULTS: Congo red binding and urease activity of Bvg+ B. bronchiseptica cultures in different liquid media were compared with the expression of virulence markers such as filamentous haemagglutinin and some outer membrane proteins (OMP). The correlation with the reference virulence markers allowed the establishment of cut-off values for the proposed markers to assure the virulent phenotype (> or = 26 nmol ml-1 of CR and < or = 2.6 U). Using both assays, modulated cultures with avirulent phenotype (Stainer-Scholte broth, with MgSO4 20 mmol l-1 and brain heart infusion broth) and semi-modulated cultures with intermediate phenotypes (tryptose phosphate broth and 83% Stainer-Scholte with MgSO4 5 mmol l-1 cultures) could be distinguished. CONCLUSION: CR binding assay and urease activity are specific and sensitive enough to detect intermediate phenotypes that could only be detected by subtle changes in OMP profiles. SIGNIFICANCE AND IMPACT OF THE STUDY: The production of effective veterinary vaccines is hampered by reversible B. bronchiseptica antigenic modulation. The proposed assays are technically suitable for selection of virulent cultures to optimize vaccine production.

Bacterial Outer Membrane Proteins↗
PubMedDate not supplied

[Presence in People's Republic of Congo of Sergentomyia decipiens, Sergentomyia dissimillima, Sergentomyia tauffliebi, Sergentomyia wansoni and Sergentomyia squamipleuris (author's transl)].

The authors indicate the presence in People's Republic of Congo of the five following sandflies: Sergentomyia decipiens Theodor, 1931; Sergentomyia dissimillima Abonnenc, 1972; Sergentomyia tauffliebi Abonnenc and Cornet, 1971; Sergentomyia wansoni Parrot, 1938 and Sergentomyia squamipleuris Newstead, 1912. They give the check-list of sandflies of Congo on the 31st may 1976 and a map of their geographical distribution.

Animals↗
PubMed1983

Diagnosis of minute cancers by the endoscopic Congo red--methylene blue test.

The clinicopathological features of minute cancers of the stomach were investigated, and the accuracy of diagnosis of minute cancers by routine endoscopic examinations and by the endoscopic Congo red - methylene blue test were compared. From 1959 to 1979, 56 minute cancer were found in 54 patients. Minute cancers are defined as those of less than 5 mm in the longest diameter. None involved the muscularis propria, but when minute cancers, especially the depressed type, were more than 4 mm in diameter, cancer cells were frequently found to invade the submucosa. Therefore, minute cancers must be diagnosed as early as possible. A correct diagnosis of minute cancers was made in only 25.0% of the cases by routine endoscopic examinations. But with the Congo red--methylene blue test the diagnostic rate was raised significantly to 75.0%. In this test, tumors are seen as areas in which the dyes become bleached to white, in sharp contrast to the unaffected mucosa. This test is more accurate than other methods for diagnosis of minute cancers, because the target area can be biopsied with greater accuracy.

Adenocarcinoma↗
PubMed1970

Congo red dichroism with dispersed amyloid fibrils, an extrinsic cotton effect.

The spectral absorption, optical rotatory dispresion, and circular dichroism associated with interaction of Congo red dye with partly purified suspensions of amyloid fibril fragments were examined. A set of phenomena consistent with a Cotton effect was found. A nearly identical set of phenomena was obtained with poly-L-lysine in its alpha-helical form. The dichroism seen when Congo red binds to amyloid substance in tissue sections can also be interpreted as a Cotton effect. This suggests that some special conformation, presumably in protein, is present in a major constituent of amyloid. This conformation is not present in gamma globulin, Bence-Jones protein, albumin, fibrinogen, or other proteins tested so far. These and other optical properties of amyloid substance can be used to compare amyloid deposits in different human cases and in different species. Extension of the use of polarization microscopy with other dyes that bind to other substances in tissue sections should permit more exquisite probing of the conformation of important macromolecules in situ in cells and tissues than has hitherto been possible.

Amyloid↗