Basic Fuchsin Dye as the First Fluorophore for Optical Sensing of Morpholine in Fruits Crust and Urine Samples.

In this work, basic fuchsin (BF) dyestuff was presented as the first optical sensor used for the spectrofluorimetric assessment of morpholine (MOR) where BF exhibits morpholine-sensing behavior. The developed fluorimetric avenue is sensitive, facile, selective, and validated for assaying the sensitizing influence of MOR on the BF fluorescence in an aprotic dioxane solvent. Parameters like solvents, BF concentration, order, and time of addition that influence the fluorescence intensity of the probing system were addressed. Optimizing the analytical methodology revealed a linear fluorescence sensitization within the addition of MOR in the two concentration ranges of 5 × 10-9 to 1.0 × 10-7 mol L-1 and 2.0 × 10-7 to 3 × 10-6 mol L-1. The limit of detection (LOD) and limit of quantification (LOQ) were estimated to be 2.0 × 10-9 mol L-1 (0.17 ng mL-1) and 6.66 × 10-9 mol L-1 (0.567 ng mL-1), respectively. High levels of accuracy and precision are achieved when assaying spiked MOR either in pure solutions or samples of fruit peel extract and human urine. Moreover, the green character and practicality/applicability of the method were evaluated by AGREE and BAGI metric tools. These merit outcomes provide insights into the development of fluorescent sensors for MOR detection using fluorescent dyes and meet the Food and Drug Administration's requirements for morpholine detection in real-life applications.

Development and validation of a French questionnaire that assesses knowledge, attitude, and practices toward Marburg diseases in sub-Saharan African countries.

OBJECTIVES: Marburg virus, previously referred to as Marburg hemorrhagic fever, is a highly severe and frequently fatal illness that affects humans. This study aimed to develop and validate a French questionnaire to assess knowledge, attitude, and practice toward Marburg virus disease (FKAP-MVD). STUDY DESIGN: An anonymous online survey was used, which was distributed through various platforms and emails. Data were collected from Burkina Faso, Guinea, the Democratic Republic of Congo, and Senegal. METHODS: To conduct the study, an anonymous online survey was used, which was distributed through various platforms such as Facebook, Twitter, WhatsApp, and emails. The survey was uploaded onto a Google form to facilitate data collection. Data were collected from Burkina Faso, Guinea, the Democratic Republic of Congo, and Senegal. RESULTS: Of the total sample of 510 participants, 60.0% were male, their mean age was 28.41 ± 6.32 years, 38.0% were married, 86.6% resided in urban areas and 64.1% had a university education. The questionnaire had good internal consistency; Cronbach's alpha was 0.87. The correlation between knowledge and attitude was 0.002, the correlation between knowledge and practice was 0.204, and the correlation between practice and attitude was relatively weak and negative at -0.060. This indicates the divergent validity of the questionnaire. The KMO value of 0.91 indicates a high level of adequacy, suggesting that the data are suitable for factor analysis. The Bartlett test of Sphericity yielded an approximate χ2 value of 4016.890 with 300 degrees of freedom and a P-value of 0.0001. The confirmatory factor analysis revealed 25 questions in three domains. The normed chi-square value is 1.224. The goodness of Fit Index (GFI) is 0.902, the Comparative Fit Index (CFI) is 0.982, the Root Mean Square Error of Approximation (RMSEA) is 0.033, and the Root Mean Square Residual (RMR) is 0.062. These values indicate a good fit of the model to the data. CONCLUSIONS: In general, the developed questionnaire has significant potential to inform public health initiatives and interventions related to MVD.

Effect of seasonal variation on lymphoid tissues of the lizards, Mabuya quinquetaeniata Licht. and Uromastyx aegyptia Forsk.

The thymus in the lizards Mabuya quinquetaeniata and Uromastyx aegyptia is highly involuted in winter but exhibits in the other seasons a rich lymphoepithelial organization. The splenic white pulp is severely depleted in winter but is extensively developed in spring, summer and autumn. In these seasons, the splenic lymphoid tissue of Mabuya occurs in a continuous phase throughout the organ obscuring the red pulp, whereas in Uromastyx the white pulp remains localized as periarteriolar aggregates and the red pulp is always clearly delineated. In both lizard species, gut-associated lymphoid tissue is well represented, especially in the large intestines and in Mabuya it is almost similar in different seasons. In Uromastyx, in winter, lymphoid nodules are only found in the caecum and the colon, but during warm seasons, inumerable nodules are distributed throughout the gut. The findings are important for a clearer understanding of immunologic competence in reptiles.

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. IV. Preliminary observations on the mechanism of naturally acquired resistance.

Suppression of egg production is the main parasitological manifestation of naturally acquired resistance to Schistosoma bovis in Sudanese cattle. In preliminary investigations on the mechanisms involved, 700-4,000 "suppressed" adult worms were surgically transplanted from six "resistant" donor cattle with very low fecal egg counts (0-8 eggs/g, epg) into six normal recipients. After transplantation, large numbers of eggs were excreted in the feces of the recipient cattle, beginning at between 5 and 16 days after operation, and reaching counts of 55-405 epg at between 6 and 20 days post transplantation. In the cattle with the highest egg counts, egg counts soon fell sharply from peak levels, whereas in cattle with lower peak counts, more steady counts were maintained. All the recipients were perfused at days 46-56, when between 0.1% and 78.5% of the transplanted worms were recovered. In the second experiment, 1,000-ml quantities of pooled sera from "resistant" donors were injected intraperitoneally into each of four normal recipient calves, while another four were injected with pooled sera from uninfected cattle. All the calves were challenged percutaneously the next day with 7,500 cercariae each, and the course of infection was followed by parasitological and clinical measurements until perfusion 18 weeks later. The results showed that the "immune" sera had a negligible effect on the numbers of worms which developed, and had no significant effect on the fecal egg counts or clinical parameters studied. There was, however, some evidence from the tissue egg counts of a reduction in the fecundity of the worms in calves injected with "immune" sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. I. Epizootiological observations on Schistosoma bovis in the White Nile Province.

A 2-year epizootiological study was carried out on Schistosoma bovis in cattle in an enzootic area of the Sudan. The prevalence of infection, as judged by the Pitchford fecal egg counting technique, was very high, approaching 90% in 1.5-year-old animals. There was, however, a lower prevalence in older cattle, and this trend was also seen with the fecal egg counts. This suggests that the cattle gradually acquire resistance to reinfection, particularly since there seems to be little age-related variation in the amount of water contact. Monthly incidence rates, estimated from fecal examinations of initially uninfected "tracer" calves showed a marked seasonal pattern, being much higher in the hot summer months, and snail infection rates showed a similar seasonal pattern. In addition, both the monthly incidence measurements and the snail infection rates showed that transmission was much heavier in 1976 than in 1977. Epizootics such as those recorded previously in this area presumably arise from exceptionally intense transmission years.

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. II. Experimental demonstration of naturally acquired resistance to Schistosoma bovis.

Epizootiological observations on Schistosoma bovis in cattle at Kosti, Sudan, showed a significant fall in age-specific prevalence and intensity with age, based on fecal egg count. To test the possibility that this is due to acquired resistance, Kosti cattle and a control group of cattle of similiar breed and age from a nonenzootic area were experimentally challenged with 70,000 S. bovis cercariae. Clinical observations showed very clearly that the Kosti cattle were able to withstand almost completely the effects of the challenge, whereas the controls developed lethal infections. Resistance was further demonstrated by clear differences between the two groups in terms of their body weights, hematological measurements, histopathological and pathophysiological responses, and worm and egg counts. The data suggested that the main basis of the resistance was a suppression of egg production by the worms from the challenge, rather than absolute prevention of their maturation. There was also evidence of a suppression of the fecundity of worms in the naturally infected Kosti cattle.

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. III. Field testing of an irradiated Schistosoma bovis vaccine.

Previous work has shown that cattle can acquire a strong resistance to Schistosoma bovis infection following repeated natural exposure. Partial resistance to a laboratory challenge with S. bovis has also been demonstrated in calves after immunization with an irradiated schistosomular or cercarial vaccine. The aim of the present study was to see whether this type of vaccine could protect calves under the very different conditions of natural exposure to S. bovis in the field. Thirty 6- to 9-month-old calves were each immunized with 10,000 irradiated S. bovis schistosomula by intramuscular injection and 8 weeks later were released into an enzootic area along with 30 unvaccinated animals. The calves were followed up for 10 months, during which period protection was evidenced by a lower mortality rate, a slower rate of acquisition of infection, and lower fecal egg counts in the vaccinated calves. Necropsy of the survivors showed 60--70% reductions in worm and tissue egg counts of the vaccinated calves as compared to those not vaccinated.

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. V. The effect of praziquantel therapy on naturally acquired resistance to Schistosoma bovis.

Studies in the White Nile area of the Sudan have shown that Zebu cattle acquire a high degree of resistance to Schistosoma bovis as a result of repeated natural exposures without, however, being able to eliminate their populations of adult schistosomes, although these do show greatly suppressed fecundity. To test whether these adult worms are necessary for the maintenance of resistance we cured six "naturally resistant" cattle (TC group) with a double treatment of 25 mg/kg praziquantel and compared their response to a 70,000 cercariae challenge with groups of "naturally resistant" but untreated cattle (UC group) and with previously unexposed, challenged cattle (CC group). Challenge was carried out 7 weeks after the second dose of praziquantel. The results confirmed that untreated cattle are "naturally resistant" and also showed that resistance was not abrogated by cure of the naturally-acquired infections. Thus, fecal egg counts after challenge reached mean maxima of 2,432 eggs per gram (epg) in the CC, but only 5 epg and 28 epg in the TC and UC groups, respectively. Similarly, mean worm counts were 85% and 69% lower in the TC and UC groups, respectively, and mean tissue egg densities were reduced by 72-99%, and 56-80%. Histopathologically, the TC and UC groups were also far less affected than the CC. Effective praziquantel treatment does therefore not destroy naturally acquired resistance to S. bovis, and may benefit infected livestock even in the absence of transmission control. The situation in human schistosomiasis is less clear, but there are several epidemiological and experimental indications of a similar conclusion for S. mansoni.

Observations on cattle schistosomiasis in the Sudan, a study in comparative medicine. VI. Demonstration of resistance to Schistosoma bovis challenge after a single exposure to normal cercariae or to transplanted adult worms.

Calves were immunized with Schistosoma bovis by a single experimental exposure to 10,000 normal cercariae. Some of these calves were perfused 14 weeks later, and a part of their worm loads was surgically transplanted into groups of normal recipient calves: "WPR" group calves received 500 pairs of worms; "MR" group calves received between 650 and 1,000 male worms alone. All three groups were subsequently challenged 10 weeks after surgery with 20,000 cercariae, as were a previously unexposed group of controls ("CC"). Mean post-challenge fecal egg counts in the animals immunized with cercariae ("PC" group) rose to a maximum of only 60 eggs per gram (e.p.g.), compared to 376 e.p.g. in the CC, and maximum fecal egg counts in the WPR and MR groups were also somewhat lower than in the CC, at 152 and 250 e.p.g., respectively. In spite of the much lower fecal egg counts in the PC than in the CC group, calculated adult "challenge" worm recoveries were only reduced by 11%, but PC group tissue egg densities derived from the challenge were 78-100% lower than in the CC. The WPR and MR groups had 43% and 37%, respectively, fewer worms than the CC, and mean tissue egg densities were lower by 39-63% and 63-76%, respectively, though in most cases there were no statistically significant differences from the CC.(ABSTRACT TRUNCATED AT 250 WORDS)

The pathogenesis of experimental Haemonchus longistipes infection in camels.

The pathogenesis and clinical signs of Haemonchus longistipes infection were studied in four experimentally infected camels two of which were adults and the other two were young. In the former animals, an acute infection developed, characterized by mucoid diarrhoea, anorexia, anaemia, loss of body weight, oedema of the lower parts of the limbs, general malaise and death at 8-10 weeks post-infection. In the two younger camels, a less dramatic disease was encountered with less severe symptoms and no oedema, but also terminating fatally at 19-20 weeks post-infection. Parasitological, haematological and biochemical parameters were determined during the course of the infection and were mostly comparable with those usually encountered in haemonchosis of other animals.

Prevalence of toxoplasmosis in Saudi Arabian camels (Camelus dromedarius).

Serum samples from 227 Saudi Arabian camels were examined for Toxoplasma gondii antibodies by the indirect haemagglutination test, using a microtitre technique. Agglutinations (greater than 2+) occurring at 1:64 dilution were considered positive. A total of 36 (16%) camels were serologically positive for toxoplasmosis, giving titres ranging between 1:64 and 1:8192. The prevalence was much higher in female compared to male camels and in adults compared to young individuals.

The pathology of nasopharyngeal myiasis in Saudi Arabian camels (Camelus dromedarius).

Thirty-two out of thirty-five camels examined at Jeddah and Riyadh slaughter houses were infected with the camel nasal bot Cephalopina titillator. The larvae occurred mainly in the nasopharynx and, occasionally, degenerated larvae were found embedded between the turbinated bones. In the pharynx, the pathological changes included the formation of lymphoid nodules, with central abscesses, at the sites of larval attachment, and a combination of inflammatory, degenerative and reparative processes in other parts of the pharyngeal wall. The nasal cavity was congested and filled with mucus in which some larvae were entangled.

The prevalence and pathogenesis of naturally-occurring Haemonchus longistipes infection in Sudanese camels.

Camel haemonchosis is prevalent in the Sudan, especially during the rainy season, with a decrease in prevalence in the dry season possibly due to delayed maturation of the worms. The naturally occurring disease in Sudanese camels is characterized by emaciation, anaemia, oedema of the lower parts of the limbs, eosinophilia, hypoproteinaemia, hypoalbuminaemia, hyperglobulinaemia and eosinophilia, as well as elevated blood urea concentrations.

The pathogenesis of experimental Haemonchus longistipes infection in goats.

Goats are highly susceptible to Haemonchus longistipes and could therefore serve as an inexpensive model to study camel haemonchosis. The course of the disease in goats is similar to that in camels and to H. contortus infection in sheep and goats. Unlike the age-dependency of camel haemonchosis, however, the severity of H. longistipes infection in goats is dose-dependent and varies from mild to hyperacute.

The pathogenesis of experimental Schistosoma bovis infections in Sudanese sheep and goats.

The pathogenic effects of experimental Schistosoma bovis infection in Sudanese sheep and goats were investigated by a variety of clinical, parasitological, physiological and histopathological techniques; uninfected animals of each species were used as controls. Infected animals of both species lost or failed to gain weight and developed a haemorrhagic diarrhoea, inappetence, marked anaemia, hypoalbuminaemia, hyperglobulinaemia, hyperproteinaemia and eosinophilia. These changes first became noticeable around the time of onset of oviposition and their severity was generally related to faecal egg counts. Red cell breakdown and albumin catabolism were much higher in infected than in control animals of the same species, and it was concluded that these changes were due to haemorrhage resulting from the extrusion of large numbers of eggs through the intestinal mucosa. Although all the animals were infected with the same number of cercariae, both the number of worms reaching maturity and the tissue egg counts tended to be higher in sheep than in goats. On the other hand, goats had significantly higher faecal egg counts than sheep and it is suggested that this was the reason for the generally more severe disease in the former species.

Erythrokinetics and albumin metabolism in primary experimental Schistosoma bovis infections in Zebu calves.

Red cell kinetics and albumin metabolism were studied in calves infected with either 100 or 200 Schistosoma bovis cercariae per kg body weight, by the use of 59Fe-labelled transferrin, 51Cr-labelled erythrocytes and 125I-labelled albumin; a third group of worm-free animals acted as controls. The anaemia which developed in the infected calves was shown to be due basically to an accelerated rate of red cell loss from the circulation, and became evident around the seventh week of infection, increased in severity during the following two months, and subsequently subsided. In view of its close similarity to the pattern of faecal egg excretion, it was concluded that haemorrhage into the intestine caused by the exit of eggs was the principal aetiological factor: haemolysis was excluded by the absence of both splenomegaly and hyperferraemia . Erythropoiesis was also accelerated in infected animals, but could not keep pace with the rate of red cell breakdown to which the animals were concurrently subjected. Haemodilution was involved, but not to a significant extent. The hypoalbuminaemia associated with infection was caused by an increased rate of albumin catabolism, and a plasma volume expansion, and was accompanied by marked depletion of all albumin pools, but particularly the extravascular pool. The pattern of albumin catabolism closely followed that of red cell loss, suggesting that passage of plasma as whole blood into the intestine was the basic cause of hypoalbuminaemia. Red cell losses and albumin hypercatabolism were more severe in the more heavily infected group, and although both subsided as egg counts fell, they remained evident even 1 year after infection. This may partly explain the failure of infected animals to regain the weight lost during earlier stages of disease.

Age specific prevalence and intensity of Schistosoma bovis infection in Sudanese Desert sheep in the White Nile Province.

A survey of ovine schistosomiasis was carried out in a Schistosoma bovis enzootic area in the central Sudan. Three hundred Desert sheep, representing different age groups, were screened for infection, using Pitchford's faecal egg counting technique. No infection was detected in animals under one year old, but from the age of 18 months onward, the prevalence increased progressively from around 20 per cent to 60 per cent in six-year-old sheep, and this was accompanied by an increase in infection intensity, as determined by faecal egg counts. These findings, which suggest that these sheep did not develop an effective resistance to schistosomiasis, contrasted with those previously recorded in cattle from the same locality, studied in the same year.

Effects of praziquantel and metrifonate on Schistosoma bovis infections in Sudanese cattle.

Twelve nine-month-old zebu calves were each experimentally infected with 10,000 Schistosoma bovis cercariae. Four were treated orally with 20 mg/kg praziquantel at weeks 9 and 14 after infection, and four were treated orally three times with metrifonate at week 11 (25 mg/kg) and again at week 14 (50 mg/kg). Praziquantel proved to be highly effective, reducing faecal egg counts near to zero; the mean live worm count in the treated calves at week 16 was only 32, compared to 2850 in the untreated group, a reduction of 98.9 per cent. In contrast, metrifonate treatment caused only a very short-lived, partial reduction in faecal egg counts, and no reduction in live worm counts.

Schistosoma bovis in calves: the development and clinical pathology of primary infections.

The clinico-pathological effects of Schistosoma bovis were monitored in zebu calves for a year after exposure to 100 or 200 cercariae/kg body weight and were related to the number and reproductive activities of the parasites present. The disease was characterised by diarrhoea, weight loss or poor weight gain, anaemia, serum protein changes and eosinophilia. These changes were broadly related to the level of infection and were most prominent during the two months following patency when faecal egg counts were highest. Subsequently, the condition of most animals improved. This was associated with a marked reduction in faecal egg excretion which in turn was related to worm deaths, reduced worm fecundity and egg retention in the tissues.

Coagulation profile and platelet parameters of the Arabian sand gazelle (Gazella subgutturosa marica): comparison with humans and camels.

During March 2009, we evaluated the hemostatic profile and platelet indices of 18 Arabian sand gazelles (Gazella subgutturosa marica) and compared the results with those from humans and camels (Camelus dromedarius). Gazelles and camels had shorter activated partial thromboplastin times, lower proconvertin and higher antihemophilic factor coagulation activity, and plasma fibrinogen levels than humans. Prothrombin time was longer in sand gazelles and shorter in camels than it was in humans. Plasma thromboplastin component, Stuart factor, and plasma thromboplastin antecedent were similar in gazelles, humans, and camels, whereas the platelet count of the sand gazelle was significantly higher than it was for camels and humans.