Hydrogen sulphide alleviates cadmium stress in Trigonella foenum-graecum by modulating antioxidant enzymes and polyamine content

Cadmium (Cd) toxicity reduces growth and yield of crops grown in metal-polluted sites. Research was conducted to estimate the potential of hydrogen sulphide (H₂ S) to mitigate toxicity caused by Cd in fenugreek seedlings (Trigonella foenum-graecum L.). Different concentrations of CdCl₂ (Cd1-1 mM, Cd2-1.5 mM, Cd3-2mM) and H₂ S (HS1-100 µM, HS2-150 µM, HS3-200 µM) were assessed. Seeds of fenugreek were primed with sodium hydrosulphide (NaHS), as H₂ S donor. Seedlings growing in Cd-spiked media treated with H₂ S were harvested after 2 weeks. Cd stress affected growth of fenugreek seedlings. Cd toxicity decreased leaf relative water content (LRWC), intercellular CO₂ concentration, net photosynthesis, stomatal conductance and transpiration. However, application of H₂ S significantly improved seedling morphological attributes by increasing the activity of antioxidant enzymes, i.e. APX, CAT and SOD, in Cd-contaminated soil. H₂ S treatment also regulated phenolic and flavonoid content. H₂ S-induced biosynthesis of spermidine (Spd) and putrescine (Put) could account for the enhancement of growth and physiological performance of fenugreek seedlings under Cd stress. H₂ S treatment also reduced H₂ O₂ production (38%) and electrolyte leakage (EL, 51%) in seedlings grown in different concentrations of Cd. It is recommended to evaluate the efficacy of H₂ S in alleviating Cd toxicity in other crop plants.

Ciproxifan attenuates the memory impairment induced by lipopolysaccharide through modulation of cholinergic transmission in the mouse brain

OBJECTIVE

We investigated the protective effect of ciproxifan on lipopolysaccharide (LPS)-induced memory impairment by altering the cholinergic system in a mouse model.

MATERIALS AND METHODS

Groups of mice were given ciproxifan (1 or 3 mg/kg, p.o.) for 30 days. Neurotoxicity was induced with four doses of LPS (250 µg/kg, i.p.) from day-22 to day-25 of drug treatment in three groups. Then, mice were subjected to behavioral assessments using tests [elevated plus maze (EPM), novel object recognition (NOR), and Y-maze]. Also, brain tissues were collected for estimation of cholinergic transmission [acetylcholine (ACh) and acetylcholinesterase (AChE) levels].

RESULTS

Ciproxifan could rescue the memory impairment caused by LPS by shortening the transfer latency in the EPM test, increasing the time spent to explore a novel object and increasing the Discrimination Index in the NOR test and increasing the number of entries to the novel arm and duration of time spent in the novel arm in the Y-maze test. Ciproxifan increased the levels of ACh by decreasing AChE activity in LPS-treated mice.

CONCLUSIONS

Ciproxifan treatment can improve memory impairment in mice by increasing ACh levels and decreasing AChE levels.

Evaluation of hepatoprotective effect of Nebivolol and sodium copper Chlorophyllin on CCL4-induced hepatotoxicity in mice

OBJECTIVE

In this study, the protective effect of sodium copper chlorophyllin and nebivolol was evaluated in a mice model of CCL4 induced hepatotoxicity. Silymarin was used as a traditional hepatoprotective drug.

MATERIALS AND METHODS

Thirty (30) mice were used as they were divided into five groups: the first group was the control group which received distilled water + olive oil, the second group which received 1.5 ml/kg of CCl4 diluted in olive oil three times a week, the third group which received CCl4 + Silymarin 50 mg/kg/day, the fourth group which received CCl4 + nebivolol 4 mg/kg/day, and the fifth group which received 1.5 ml/kg of CCl4+ Cu-chlorophyllin 50 mg/kg/day. The drugs were given by intraperitoneal route for 5 weeks. The detection, quantification of CCl4 induced hepatotoxicity and possible protective effect of either silymarin, nebivolol, or sodium copper chlorophyllin were assessed using biochemical analysis of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein, lipid profile, an assay of oxidants and antioxidants, assay of interleukin 6 (IL6) and tumor necrosis factor-alpha (TNF-α), and histopathological examination.

RESULTS

The administration of carbon tetrachloride (CCl4) produced pronounced liver impairment. It significantly increased ALT, AST, ALP, malondialdehyde, and serum nitric oxide levels compared to normal control group besides a decrease in total protein, serum catalase, tissue SOD, and GSH levels. IL-6 and TNF-α levels were significantly higher while total cholesterol was significantly lower in mice receiving CCL4 compared to the normal control group. CCL4 induced severe hyperemia and congestion inside the portal area with leukocytic infiltration, hepatic degeneration, and bridge fibrosis.

CONCLUSIONS

Co-administration of either silymarin, nebivolol, or sodium copper chlorophyllin with CCl4 was able to ameliorate up to almost contradict CCl4 induced hepatic injury through their anti-inflammatory and antioxidant activities.

Core–shell polymer nanocomposite based on free radical copolymerization of anthranilic acid and o-amino phenol in the presence of copper hexacyanoferrates nanoparticles and its adsorption properties

Core–shell polymer nanocomposite (CSNC) of copper hexacyanoferrate-copolymer of anthranilic acid with o-aminophenol (CHCF-poly(AA-co-OAP)) was synthesized and used as ion exchanger for the sorption of cesium ions from aqueous solution. The nanocomposite was prepared by implantation of CHCF nanoparticles into copolymer of poly(AA-co-OAP) during the polymerization process. The surface morphology and the porous structure were investigated through transmission electron microscope (TEM), scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET). The characterization of the prepared (CSNC) was carried out by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Thermogravimetric (TGA). Which SEM and TEM images confirmed the nano-size of the prepared CSNC. The values of adsorption capacity of CSNC towards cesium ions and the factors influence on the removal of cesium from solutions were investigated as function in pH, metal ion concentration, temperature and contact time. The results illustrated that the highest value of sorption capacity of the prepared CSNC towards Cs+ ions was 2.1 mmol g−1 at pH 11, 10 mmol L−1 Cs+ and 25 °C. Four modeling include on Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherms models were studied. According to the obtained data, Langmuir model considered the most suitable model, which suggest that the uptake of Cs+ was monolayer and homogeneous. Also, the adsorption kinetics data was fitted well to pseudo-second-order model. Thermodynamic parameters were calculated in the temperature from 25 to 60 °C and the data revealed that Cs+ sorption was endothermic, spontaneous, and more favorable at higher temperature. Up to 92% desorption of Cs+ was completed with 2 M KCl.

Influence of Cr-doping on structural, magnetic and dielectric properties of M-type hexaferrites synthesized using microwave digestion technique

M-type hexaferrite SrCrxFe12-xO19 compounds doped with Cr (x = 0, 1, 2, 3 and 4 at.%) were prepared by microwave digestion system. X-ray diffraction was used to study the structure and crystallization of the samples. The samples are found to have a hexagonal phase, SrFe12O19, as a main phase at 2θ ≈ 33.144° and 35.618° for x = 0 and 1 respectively, and 32.451° and 34.295° for x ≥ 2. The Rietveld refined parameters such as the lattice parameters (a = b, c), direct and indirect cell volume, crystallite size and microstrain were investigated. TEM and SEM results showed that the samples have hexagonal shape and grain size range from 126 nm to 379 nm. Magnetization, M, as a function of the applied magnetic field, H, was obtained from the hysteresis loop. The coercive field, H C , saturation, M s and remnant, M r , magnetization and squareness ration, M r /M s , were extracted from the hysteresis loop results. These results revealed that H C is inversely proportional with the grains size of the samples but directly proportional with Cr-doping values candidating these compounds to be used in computer hard disk memories applications. M values are inversely proportional with Cr-doping values. The variation of conductivity, σ, impedance, Z, dielectric constant, ε, dielectric loss factor, tan δ and dissipation factor as functions of both AC frequency, F(Hz) and Cr-doping, x, were investigated. The maximum value of the dissipation factor was at x = 2 which equals 8.05 × 109 m F−1 when F = 2 × 105 Hz. The impedance of the samples behaved as a capacitor reactance that makes our compounds candidate for many crucial dielectric applications.

Modeling of thermal studies on melt quenched Ge18Bi4Se78 chalcogenide

The crystallization characteristics for Ge18Bi4Se78 glass are studied in this work by means of differential thermal analysis (DTA) under non-isothermal conditions. One stage endothermic glass transition and one exothermic crystallization are observed in the DTA curves. The results of topological constraints for Ge18Bi4Se78 glass show that the calculated value of glass transition temperature (Tg) is very close to that of the experimental results. The as-prepared, as well as the annealed samples, are examined using x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX), scan electron microscope (SEM) techniques. Avrami’s exponent (n) found to have an average value of 1.61 ± 0.2 reveals a mixture of one dimensional and surface nucleation stages of growth. Many models are used to estimate the activation energies for glass transition (Eg) and crystallization (Ec). The crystallization process was found to be described by the Sestak- Berggren SB(M, N) model.

Exogenous melatonin-mediated regulation of K+ /Na+ transport, H+ -ATPase activity and enzymatic antioxidative defence operate through endogenous hydrogen sulphide signalling in NaCl-stressed tomato seedling roots

Melatonin (Mel) and hydrogen sulphide (H₂ S) have emerged as potential regulators of plant metabolism during abiotic stress. Presence of excess NaCl in the soil is one of the main causes of reduced crop productivity worldwide. The present investigation examines the role of exogenous Mel and endogenous H₂ S in tomato seedlings grown under NaCl stress. Effect of 30 µm Mel on endogenous synthesis of H₂ S was examined in roots of NaCl-stressed (200 mm) tomato seedlings. Also, the impact of treatments on the oxidative stress markers, transport of K⁺ and Na⁺ , and activity of H⁺ -ATPase and antioxidant enzymes was assessed. Results show that NaCl-stressed seedlings supplemented with 30 µm Mel had increased levels of endogenous H₂ S through enhanced L-cysteine desulfhydrase activity. Mel in association with H₂ S overcame the deleterious effect of NaCl and induced retention of K⁺ that maintained a higher K⁺ /Na⁺ ratio. Use of plasma membrane inhibitors and an H₂ S scavenger revealed that Mel-induced regulation of K⁺ /Na⁺ homeostasis in NaCl-stressed seedling roots operates through endogenous H₂ S signalling. Synergistic effects of Mel and H₂ S also reduced the generation of ROS and oxidative destruction through the enhanced activity of antioxidant enzymes. Thus, it is suggested that the protective function of Mel against NaCl stress operates through an endogenous H₂ S-dependent pathway, wherein H⁺ -ATPase-energized secondary active transport regulates K⁺ /Na⁺ homeostasis.

[Vitamin D and urinary stone disease: the current state of problem]

Disturbances of vitamin D metabolism is one of the factors leading to the impairment of phosphate and calcium homeostasis which plays leading role in the development of urinary stone disease. Vitamin D is necessary for wide spectrum of physiologic processes and good health condition. Until now, in many guidelines on urolithiasis there is an advice to limit vitamin D intake due to concerns of an increase in the stone formation. In vivo studies have shown that 1,25()2D3 can both increase and decrease and not to influence on calcium excretion. The results of the studies assessing the relationship between vitamin D blood/plasma level and urinary stone disease are often inconsistent and even controversial. In patients with urinary stone disease the vitamin D deficiency is often found and currently there is still a lack of studies dedicated to problem of vitamin D deficiency in patients with urinary stone disease and the need for its correction.

Antibacterial activity of extracted bioactive molecules of Schinus terebinthifolius ripened fruits against some pathogenic bacteria

The aim of this work is to identify the chemical constituents and the bioactivity of essential oil (EO), acetone extract (ACE) and n-hexane extract (HexE) of S. terebinthifolius ripened fruits using GC-MS. Total phenolic content and antioxidant activity of extracts were determined using the Folin-Ciocalteu and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assays, respectively. The toxicity against the growth of Acinetobacter baumannii, Bacillus subtilis, Escherichia coli, Micrococcus flavus, Pseudomonas aeruginosa, Sarcina lutea, and Staphylococcus aureus was determined with measuring the inhibition zones (IZs) using the disc diffusion method at the concentrations from 125 to 2000 μg/mL, also, the minimum inhibitory concentrations (MICs) using 96-well micro-plates and ranged from 4 to 2000 μg/mL. The major components in EO were α-pinene (36.9%), and α-phellandrene (32.8%). The major components in ACE were oleic acid (38.7%), α-phellandrene (13.33%), and δ-cadinene (11.1%), while the major methyl esters of fatty acids detected in HexE were oleic (12.8%), and palmitic (10.9%). The EO showed good activity against the growth of Staph. aureus and P. aeruginosa with MIC values of 16 μg/mL and 32 μg/mL, the ACE showed broad activity against the studied bacterial pathogens with MIC values ranged from of 4-128 μg/mL against the studied bacterial isolates, while HexE, however, showed weak antibacterial activity. The IC₅₀ values of EO, ACE and HexE were 15.11 ± 0.99, 118.16 ± 1.7 and 324.26 ± 2.45 μg/mL, respectively, compared to IC₅₀ of Tannic acid (23.83 ± 1.9 μg/mL) and butylated hydroxytoluene (BHT, 2.9 ± 0.1 μg/mL). Data suggested that the ripened fruits of S. terebinthifolius have potent antioxidant and antibacterial activities.

Molecular characterization of aflatoxigenic and non-aflatoxigenic Aspergillus flavus isolates collected from corn grains

Twelve species from six fungal genera were found to be associated with corn (Zea mays L.) grain samples collected from three main regions of Saudi Arabia. The average frequencies of the most common genera were Aspergillus (11.4%), Fusarium (9.5%), Penicillium (5.1%), and Alternaria (5.8%). Fifteen isolates of Aspergillus flavus were screened by HPLC for their ability to produce aflatoxins (AF). The percentage of aflatoxigenic A. flavus isolates was 53%. Eight isolates produced AF, at concentrations ranging 0.7-2.9 ppb. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) molecular markers were used to genetically characterize isolates of A. flavus and to discriminate between the aflatoxigenic and non-aflatoxigenic isolates. RAPD and ISSR analysis revealed a high level of genetic diversity in the A. flavus population, which was useful for genetic characterization. The clustering in the RAPD and ISSR dendrograms obtained was unrelated to geographic origin. The RAPD and ISSR markers could not discriminate between aflatoxigenic and non-aflatoxigenic isolates, but the ISSR primers were somewhat better.

Problems in assessing rationality of drug utilization in less developed countries

Less developed countries are facing various difficulties in assessing rationality of drug utilization. The problems are essentially related to four major areas; (a) Policies, administration and management, (b) Practice and services, (c) Education and training, (d) Monitoring and research. Drug policies have often failed to recognise the importance of identifying the levels of rationality of the various components of drug utilization. Consequently, neither the need nor the mechanisms to assess rationality were considered. Drug utilization data and records have been poorly developed and maintained, e.g. mal-managed, inaccurate, and without continuity with regard to collection, monitoring and evaluation. Provision and supply of drugs were handled by an unnecessary multiplicity of departments and state offices, none of which keeping complete records and/or information in relation to needs of drugs nor other health care requirements. Deficiencies and shortcomings associated with medical/pharmaceutical practice, services, education and training have as well contributed significantly to the failure of the less developed countries to assess and promote rationality of drug utilization.

Distribution of radium in oil and gas industry wastes from Malaysia

Radium concentrations in 470 samples of the various types of waste from oil and gas industries were analysed using gamma spectrometers. The results showed that the radium concentration varied within a wide range. The highest mean 226Ra and 228Ra concentrations of 114,300 and 130,120 Bq/kg, respectively, were measured in scales. Overall, 75% of the waste, mostly sludge and extraction residue lies within the normal range of radium concentration in soils of Malaysia. However, some platform sludge can have radium concentration up to 560 Bq/kg.

Rapid and simple chromatographic method for the determination of diazepam and its major metabolites in human plasma and urine

A simple, rapid, sensitive and selective HPLC method has been developed for the analysis of diazepam (DZP) and its major metabolites, N-desmethyldiazepam (DMDZP), temazepam (TZP) and oxazepam (OZP), in plasma and urine, using clonazepam (CZP) as the internal standard and chloroform as the extracting solvent, with a 10 ng/ml limit of quantitation for the four assayed drugs, and an average (+/-S.D.) recovery of 87.7+/-6.46%, 92.9+/-5.31%, 91.4+/-4.01% and 91.7+/-2.68% for DZP, DMDZP, TZP and OZP, respectively (from plasma), and 89.6+/-2.26%, 90+/-4.24%, 87.45+/-0.64% and 94.50+/-0.71% for DZP, DMDZP, TZP and OZP, respectively (from urine). The method has also proved to be selective and reproducible.

Effect of Khat chewing on the bioavailability of ampicillin and amoxycillin

The study examined the effect of Khat chewing on ampicillin and amoxycillin bioavailability following the administration of a 500 mg single dose of each antibiotic at different times relative to Khat chewing. Using a urinary excretion method the bioavailabilities of ampicillin and amoxycillin were determined in eight healthy adult male Yemeni volunteers. The extent and rate of ampicillin bioavailability were reduced significantly by Khat chewing except when administered 2 h after the Khat chewing session. However, the bioavailability of amoxycillin was only significantly reduced when the antibiotic was taken midway through the Khat chewing session. It was concluded that the two antibiotics, particularly ampicillin, should be taken 2 h after Khat chewing.

A prospective, randomized controlled trial of inpatient versus outpatient continence programs in the treatment of urinary incontinence in the female

Seventy-four patients presenting with a mixed pattern of urinary symptoms were randomly allocated to undergo either inpatient or outpatient continence programs as initial treatment, without prior urodynamic investigation. Both programs consisted of physiotherapy, bladder retraining, fluid normalization, dietary advice and general support and advice. Nine out of 39 in the outpatient group and 8 out of the 35 of the inpatient group failed to complete the study. There was a significant decrease in frequency, nocturia, number of incontinent episodes and visual analog scores for both groups. In addition the outpatients had a significant reduction in loss on pad testing, and a significantly greater improvement in their visual analog score. In each group 63% were cured or improved to the extent that they did not require further treatment. Staff costs per outpatient were half those for an inpatient. We conclude that outpatient conservative treatment as detailed above is a successful first-line treatment of urinary incontinence in women. It is as successful and possibly better than inpatient treatment, and is significantly cheaper.

Significant reduction in chloroquine bioavailability following coadministration with the Sudanese beverages Aradaib, Karkadi and Lemon

Chloroquine bioavailability in healthy males was examined following oral coadministration of 600 mg with three common Sudanese beverages, Aradaib (Tamarindus indica), Karkadi (Hibiscus sabdarifa) and Lemon (Citrus limetta) and drinking water. The tablets and beverages were taken on an empty stomach after an overnight fast. The plasma chloroquine concentrations were measured by HPLC. The extent and rate of chloroquine bioavailability were described by the area under the plasma concentrations versus time curve (AUC), the peak plasma concentration (Cmax) and with the time to reach Cmax (Tmax), respectively. The mean (+/- S.E.) AUC values after administration with water (control) and Aradaib, Karkadi and Lemon, respectively, were 7.52 +/- 0.87, 2.60 +/- 0.24, 2.16 +/- 0.30 and 2.41 +/- 0.29 mg.h/L. The corresponding mean Cmax values were 553 +/- 17.8, 184 +/- 21.3, 148 +/- 14.1 and 210 +/- 17.4 mg/L and the corresponding Tmax values were 3.0 +/- 1.0, 3.2 +/- 1.2, 2.6 +/- 0.8 and 2.5 +/- 1.0 h. The results indicate a statistically significant reduction in the AUC and Cmax of chloroquine as a result of a coadministration with each of the three beverages. A parallel reduction in the drugs antimalarial efficacy might be expected.

A strategy for promoting improved pharmaceutical use: the International Network for Rational Use of Drugs

Over the last decade, pharmaceutical selection, procurement, distribution, and financing have improved as a result of essential drugs programs. However, despite improved availability, pharmaceuticals are frequently used irrationally. The International Network for the Rational Use of Drugs (INRUD) has been established to help address this problem. The Network joins core groups of researchers from four African and three Asian countries with support groups in Boston, Sweden, WHO, and Australia. The activities of the Network are supported by multilateral, bilateral, foundation donors and by Management Sciences for Health. INRUD functions as a participatory organization in which members are involved in decision-making. The primary objective of the Network is to identify through a coordinated set of country-based research projects a set of effective interventions to recommend as policy options for the promotion of rational drug use. In developing these research projects, INRUD stresses the importance of a multi-disciplinary perspective for adequately understanding the reasons underlying inappropriate use of drugs. To better enable country groups to utilize strong research methodologies and to blend the strengths of multiple disciplines effectively, a major activity of the Network thus far has been the building of local research capacity.

Post kala-azar dermal leishmaniasis in the Sudan: clinical features, pathology and treatment

The clinical features, pathology, immune responses, diagnosis and treatment of post kala-azar dermal leishmaniasis (PKDL) in the Sudan are described and discussed. The disease is characterized by maculopapular or nodular lesions on the face, limbs or trunk. Lesions appear during or within months after the treatment of visceral leishmaniasis, but in 2 of 19 patients there was no previous history of kala-azar. PKDL may be confused with leprosy both clinically and pathologically. Similarities and differences between the 2 diseases are discussed. Unlike visceral leishmaniasis, the peripheral lymphoid cells of patients with PKDL respond to Leishmania antigen and some are leishmanin positive. The response to intravenous sodium stibogluconate (20 mg/kg for 30 d) was reasonably good but some patients required repeated or more prolonged treatment. Ketoconazole in a dose of 10 mg/kg daily for 4 weeks had no effect on PKDL.

Characterization of a gelatinase from human rheumatoid synovial fluid cells

A metalloproteinase with a specificity for gelatin was isolated from serum-free medium of cultures of rheumatoid synovial fluid. The enzyme showed all the properties of a leukocyte gelatinase. In addition to gelatin this proteinase cleaved the synthetic substrate dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg (Dnp-peptide) rapidly, while casein was a much poorer substrate. This proteinase showed no enzymatic activity against collagen type I, was secreted in a latent form and could be activated by trypsin or organomercurial compounds, such as mersalylic acid or 4-aminophenyl-mercury acetate. The latent enzyme had an apparent molecular mass of 130,000-150,000 estimated by gel filtration or 97,000 by electrophoresis on polyacrylamide gel containing sodium dodecyl sulphate. When analysed by immunoblotting the enzyme was recognized by antibodies raised against human polymorphonuclear leukocyte gelatinase. Although we found synovial fibroblasts to be largely present in the cell cultures we could not detect any fibroblast gelatinase activity.

Pharmacokinetics of praziquantel in healthy volunteers and patients with schistosomiasis

The pharmacokinetics of a novel praziquantel preparation (Distocide) were investigated in Sudanese patients with hepatosplenic schistosomiasis and in healthy volunteers, and compared with those of Biltricide. The results of the first study indicated greater (P less than 0.05) plasma concentrations of Biltricide at 1.5, 2, 3 and 5 h after administration than with Distocide; plasma elimination half-lives (t 1/2) were not significantly different. In patients with hepatosplenic schistosomiasis, higher plasma levels of Distocide were noted (P less than 0.05 at 8 h) compared to healthy controls; however, due to wide inter-individual variations, there were no significant differences in maximum plasma concentration, time to maximum plasma concentration, area under the plasma concentration curve (AUC), volume of distribution, or clearance; t 1/2 was greater (P less than 0.05) in patients (11.9 +/- 5.4 h) than controls (2.3 +/- 0.4 h). In the presence of food, higher plasma concentrations of Distocide occurred compared to the fasting state; AUCs were greater (P less than 0.01) in both food groups, although the values of t 1/2 were shorter. The lower plasma levels and longer duration of action of Distocide may be advantageous in reducing side effects and prolonging exposure of the schistosomes to the drug.

Efficacy of a new Hoffmann-La Roche compound (Ro 15-5458) against Schistosoma mansoni (Gezira strain, Sudan) in vervet monkeys (Cercopithecus aethiops)

Some compounds of the class 9-acridanone-hydrazones have recently been developed by Hoffmann-La Roche (Basel-Switzerland) and were shown to have antischistosomal effects. One of these compounds (RO 15-5458/000) was administered at two dose levels (25 mg and 15 mg/kg body-weight) to S. mansoni (Gezira strain-Sudan) infected vervet monkeys. The faecal egg-output was terminated, worm-burden killed and tissue egg-counts were greatly reduced as compared with the untreated control monkey. Severe necrotic changes were seen around dead worms in sections from treated animals' livers. The efficacy of this compound as an antischistosomal is encouraging and deserves further studying.

The effect of foster feeding and bottle feeding expressed breast-milk on the susceptibility of guinea-pig infants to influenza virus

Infant guinea-pigs born to mothers immunized against influenza virus by infection during pregnancy were reared from birth by non-immune foster mothers. As a control for the effects of fostering, a similar group were fostered to immune mothers. Fostering, regardless of the immune state of the foster-mother, increased the susceptibility of the infant to upper respiratory tract infection. Increased susceptibility was associated with ablation of the infants IgM and IgA antibody responses and reduced secretion of transplacentally acquired IgG antibody in nasal secretions. In the reciprocal experiment, infants of non-immune mothers fostered to immune mothers cleared virus more rapidly than their peers who were fed by their own mothers. This protective effect was associated with an enhanced nasal IgM and IgA antibody response. Infants of immune mothers separated from their mothers at birth and hand-reared on a cow's-milk-based formula feed suffered an increased susceptibility to the virus similar to that seen in fostered infants. Addition of a pool of expressed milk from a group of immune mothers, including their own, to the feed of hand-reared infants did not reduce their susceptibility. However, a further group of infants fed a non-cellular whey fraction of the same milk pool secreted significantly lower titres of virus. This increased protection was associated with elevated levels of IgG antibody secretion into nasal washes early in infection.

The susceptibility of breast-fed and cow's milk formula-fed infant guinea pigs to upper respiratory tract infection with influenza virus

Breast-fed infant guinea pigs from immune mothers were partially protected against infection with influenza virus when compared to those from nonimmune mothers. Virus titres in nasal washes at 24 h post-infection were reduced and virus clearance from the upper respiratory tract accelerated. When infants of immune mothers were deprived of colostrum and hand-reared on a formula-feed their ability to reduce virus yields at 24 h post-infection was lost. Infants partially breast-fed and partially formula-fed gave total virus yields similar to their fully breast-fed peers. Infants of immune mothers possessed high titres of serum IgG antibody to the virus prior to infection. Post-infection, IgG antibodies appeared on the mucosal surface of breast-fed seropositive infants earlier than for seronegative infants of nonimmune mothers but IgM and IgA responses of seropositive infants were less vigorous than those of seronegative infants. There was little evidence that antibody present in a mother's milk was transmitted to the nasal mucosa of her offspring. Fully and partly formula-fed seropositive infants showed enhanced transudation of serum IgG antibody on to the mucosal surface and this effect was most marked in the partly formula-fed group which showed greater protection. In both formula-fed groups serum and nasal IgM and IgA responses were completely suppressed.

Propranolol disposition in patients with hepatosplenic schistosomiasis

Eight Sudanese patients with hepatosplenic schistosomiasis and seven Sudanese controls were administered a single oral dose of long acting (LA), propranolol 160 mg; blood propranolol levels were measured at regular intervals for 12 h using g.l.c. In patients with hepatosplenic schistosomiasis, propranolol blood concentrations were greater (P less than 0.05) at all time intervals, Cmax 63.5 (29-143) ng ml-1 (median and range) than controls Cmax 23 (12-37) ng ml-1. Median AUC0-12 was also greater (P less than 0.05) (533 and 218 ng ml-1 h respectively), tmax were not significantly different. In patients and controls prior to treatment, standing heart rate (77.5 (60-110), 72 (68-74) beats min-1) systolic (120 (105-150), 110 (100-120) mm Hg) and diastolic blood pressure (75 (60-90), 70 (60-80) mm Hg) were not significantly different. However following propranolol administration a reduction (P less than 0.05) occurred in both systolic (median 20 mm Hg) and diastolic (median 12.5 mm Hg) blood pressure in the patients compared with controls. Heart rate was reduced by a median of 10 beats min-1 in both groups. These observations indicate that propranolol bioavailability in patients with hepatosplenic schistosomiasis is increased possibly due to reduced presystemic extraction.

Metronidazole metabolism following oral benzoylmetronidazole suspension in children with giardiasis

A suspension of benzoylmetronidazole (6.4% w/v) was given orally at a dose of 15-25 ml, equivalent to 0.6-1 g metronidazole, once a day for three days to 11 children with giardiasis. Blood samples were collected after the first and third doses for analysis of plasma metronidazole and its main oxidative metabolite by high performance liquid chromatography. Peak metronidazole concentrations were 22.60 +/- 8.52 mg/l (mean +/- S.D.) after the first dose, and 30.22 +/- 10.06 mg/l after the third dose, occurring at 3.6 +/- 1.4 and 4.4 +/- 2.9 hours post-dose, respectively. Peak concentrations of the metabolite were 4.26 +/- 1.94 mg/l after the first dose and 7.96 +/- 3.63 mg/l after the third dose, occurring 7.2 +/- 1.6 and 9.1 +/- 3.3 h post-dose, respectively. Calculation of plasma metronidazole half-life and clearance values was not possible. This study shows that oral administration of metronidazole as its benzoyl ester slows the rate of metronidazole absorption, followed by sustained plasma concentrations and a prolonged elimination phase. Giardiasis does not appear to prevent metronidazole absorption. Concurrent giardiasis is unlikely to influence metronidazole therapy for systemic anaerobic infections.