Individuals with a Rh-positive but not Rh-negative blood group are more vulnerable to SARS-CoV-2 infection: demographics and trend study on COVID-19 cases in Sudan.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In Sudan, several haematological studies were conducted to study the ABO blood group distribution among the population, in which the O blood group was dominant followed by the A blood group. However, there is no systematic study into any correlation between COVID-19 and the population's blood group types, therefore we have intended to study the possible effect of blood group on the acquisition of SARS-CoV-2 infection. A questionnaire-based case-control study was carried out on 557 individuals with COVID-19 in Sudan; factors such as age, blood group, previous malaria infection, history of ailments such as diabetes, hypertension and symptoms suffered were also considered and analysed. More women were infected than men, and individuals between 25 and 35 years were the most affected age group. O Rhesus-positive (O+) blood group was the least affected by the disease while A Rhesus-positive (A+) individuals were the most vulnerable. Fatigue, fever and loss of smell were the major symptoms among the patients, but 13% of SARS-COV-2-positive individuals remained asymptomatic. As the Sudan population is largely constituted of O Rhesus-positive inhabitants (approximately 50%) these results might explain the relatively lower COVID-19 incidence in the country.

Antibacterial activity of silver nanoparticles against field and reference strains of Mycobacterium tuberculosis, Mycobacterium bovis and multiple-drug-resistant tuberculosis strains.

Tuberculosis (TB) is an endemic disease in animals and humans in Egypt. This study aims to investigate the antimycobacterial activity of silver nanoparticles(AgNPs) by determining the minimal inhibitory concentration (MIC) of AgNPs, using the microplate Alamar blue assay. The AgNPs were chemically synthesised and their form and size were characterised by ultraviolet-visible absorption spectrophotometry, transmission electron microscopy and X-ray diffraction.The reference strains of Mycobacterium bovis and Mycobacterium tuberculosisH37Rv, and one multiple-drug-resistant (MDR) strain of M. tuberculosis were tested, as well as clinical isolates of M. bovis and M. tuberculosis. The AgNPs were tetrahydral with a few spherical particles and an average particle size of 50 nm. The mycobacterial strains were varied with MICs of AgNPs. Both reference strains of M. tuberculosis and M. bovis, in addition to the MDR strain of M. tuberculosis, were successfully inhibited by AgNPs at MICs of 1 ?g/ml, 4 ?g/ml and 16 ?g/ml, respectively, whereas clinical isolates of M. bovis and M. tuberculosis were inhibited at MIC values of 4-32 ?g/ml and 1-16 ?g/ml, respectively. The AgNPs showed an in vitro chemotherapeutic effect against Mycobacterium spp.Thus, they can be used to treat TB not only in humans but also in animals, and maybe useful in TB prevention and control strategies worldwide.

En Egypte, la tuberculose est une maladie endémique chez l'homme comme chez l'animal. Les auteurs présentent les résultats d'une étude conduite pour mesurer l'activité antibactérienne des nanoparticules d'argent (NPAg) en déterminant les valeurs de concentration minimale inhibitrice (CMI) des NPAg au moyen du test au bleu Alamar sur microplaques. Les NPAg ont été synthétisées par une méthode chimique et leur forme et taille ont été caractérisées par spectrophotométrie d'absorption dans l'ultra-violet, microscopie électronique à transmission et diffraction des rayons X. L'étude a cible les souches de référence de Mycobacterium bovis et de Mycobacterium tuberculosis H37Rv, ainsi qu'une souche multirésistante de M. tuberculosis et des isolats cliniques de M. bovis et M. tuberculosis. Les NPAg étaient à structure tétraédrique avec quelques particules sphériques ; la taille moyenne des particules etait de 50 nm.La CMI des NPAg variait en fonction des souches. L'inhibition des deux souches de reference de M. tuberculosis et M. bovis et de la souche multirésistante de M. tuberculosis était obtenue avec des CMI de NPAg de 1 ?g/ml, 4 ?g/ml et16 ?g/ml, respectivement, tandis que les isolats cliniques de M. bovis et de M. tuberculosis étaient inhibés en présence de NPAg à des CMI comprises entre 4 et 32 ?g/ml et 1­16 ?g/ml, respectivement. L'efficacité chimiothérapeutique des NPAg contre Mycobacterium spp. a été démontrée in vitro. Ces nanoparticules peuvent donc servir à traiter la tuberculose non seulement chez l'homme mais également chez les animaux et contribuer ainsi aux stratégies de prévention et de lutte contre la tuberculose dans le monde.

En Egipto, la tuberculosis es una enfermedad endemica que afecta a personas y animales. Los autores describen un estudio encaminado a analizar la actividad antimicobacteriana de las nanoparticulas de plata, determinando para ello la concentracion inhibitoria minima de nanoparticulas mediante el ensayo de microtitulacion en placa con azul Alamar. Tras sintetizar quimicamente las nanoparticulas de plata y caracterizar su forma y tamano por espectrometria de absorcion ultravioleta-visible, microscopia electronica de transmision y difraccion de rayos X, se sometieron a prueba las cepas de referencia de Mycobacterium bovis y Mycobacterium tuberculosis H37Rv, asi como una cepa multirresistente de M. tuberculosis y muestras de M. bovis y M. tuberculosis aisladas a partir de casos clinicos. Salvo unas pocas de forma esferica, las nanoparticulas de plataeran tetraedricas. Su tamano era en promedio de 50 nm. Tras someter las cepas de micobacterias a distintas concentraciones de nanoparticulas, se observo que estas inhibian el crecimiento de las cepas de referencia de M. tuberculosis y M. bovis y de la cepa multirresistente de M. tuberculosis a concentraciones minimas de 1 ?g/ml, 4 ?g/ml y 16 ?g/ml, respectivamente, mientras que las muestras clinicas de M. bovis y M. tuberculosis quedaban inhibidas por la presencia de nanoparticulas a valores de concentracion minima de 4­32 ?g/ml y 1­16 ?g/ml, respectivamente. Tambien se observo que, in vitro, las nanoparticulas de plata mostraban actividad farmacologica contra Mycobacterium spp. De ahi se sigue que pueden ser empleadas para tratar la tuberculosis no solo en personas, sino tambien en animales, y que pueden resultar utiles en todo el mundo para las estrategias de prevencion y control de la tuberculosis.

Mu opioid receptor antagonism in the nucleus accumbens shell blocks consumption of a preferred sucrose solution in an anticipatory contrast paradigm.

Binge eating, a central feature of multiple eating disorders, is characterized by excessive consumption occurring during discrete, often brief, intervals. Highly palatable foods play an important role in these binge episodes - foods chosen during bingeing are typically higher in fat or sugar than those normally consumed. Multiple lines of evidence suggest a central role for signaling by endogenous opioids in promoting palatability-driven eating. This role extends to binge-like feeding studied in animal models, which is reduced by administration of opioid antagonists. However, the neural circuits and specific opioid receptors mediating these effects are not fully understood. In the present experiments, we tested the hypothesis that endogenous opioid signaling in the nucleus accumbens promotes consumption in a model of binge eating. We used an anticipatory contrast paradigm in which separate groups of rats were presented sequentially with 4% sucrose and then either 20% or 0% sucrose solutions. In rats presented with 4% and then 20% sucrose, daily training in this paradigm produced robust intake of 20% sucrose, preceded by learned hypophagia during access to 4% sucrose. We tested the effects of site-specific infusions of naltrexone (a nonspecific opioid receptor antagonist: 0, 1, 10, and 50µg/side in the nucleus accumbens core and shell), naltrindole (a delta opioid receptor antagonist: 0, 0.5, 5, and 10µg/side in the nucleus accumbens shell) and beta-funaltrexamine (a mu opioid receptor antagonist: 0 and 2.5µg/side in the nucleus accumbens shell) on consumption in this contrast paradigm. Our results show that signaling through the mu opioid receptor in the nucleus accumbens shell is dynamically modulated during formation of learned food preferences, and promotes binge-like consumption of palatable foods based on these learned preferences.

Convergent, not serial, striatal and pallidal circuits regulate opioid-induced food intake.

Mu opioid receptor (MOR) signaling in the nucleus accumbens (NAcc) elicits marked increases in the consumption of palatable tastants. However, the mechanism and circuitry underlying this effect are not fully understood. Multiple downstream target regions have been implicated in mediating this effect but the role of the ventral pallidum (VP), a primary target of NAcc efferents, has not been well defined. To probe the mechanisms underlying increased consumption, we identified behavioral changes in rats' licking patterns following NAcc MOR stimulation. Because the temporal structure of licking reflects the physiological substrates modulating consumption, these measures provide a useful tool in dissecting the cause of increased consumption following NAcc MOR stimulation. Next, we used a combination of pharmacological inactivation and lesions to define the role of the VP in hyperphagia following infusion of the MOR-specific agonist [D-Ala2, N-MePhe4, Gly-ol]-enkephalin (DAMGO) into the NAcc. In agreement with previous studies, results from lick microstructure analysis suggest that NAcc MOR stimulation augments intake through a palatability-driven mechanism. Our results also demonstrate an important role for the VP in normal feeding behavior: pharmacological inactivation of the VP suppresses baseline and NAcc DAMGO-induced consumption. However, this interaction does not occur through a serial circuit requiring direct projections from the NAcc to the VP. Rather, our results indicate that NAcc and VP circuits converge on a common downstream target that regulates food intake.

Nucleus accumbens opioid signaling conditions short-term flavor preferences.

Opioid signaling in the nucleus accumbens (NAcc) strongly modulates flavor-based food choice. To further investigate the role of opioid signaling in taste reward, we used a sensory specific satiety (SSS) paradigm to devalue specific flavors of nutritionally identical food pellets in rats. In the NAcc, infusion of a mu opioid (MOP) receptor selective agonist selectively increased consumption of a pre-fed flavor, thus reversing the SSS effect. Conversely, blockade of endogenous opioid signaling with the opioid antagonist naltrexone selectively decreased consumption of a recently consumed flavor, potentiating the SSS effect. No enhancement of consumption was observed if a delay of 3 h was imposed following the intra-NAcc MOP agonist indicating that there were no long-term changes in flavor preference. If a delay was introduced between the initial flavor exposure and the intra-NAcc MOP agonist infusion, pellet consumption was increased non-selectively (irrespective of flavor) suggesting that close temporal contiguity between flavor experience and NAcc opioid action is critical for the opioid effect on flavor preference. In contrast to opioid effects, inactivating NAcc neurons by local microinjection of muscimol (a GABAA agonist) increased consumption of both the pre-fed and non-pre-fed flavors equally. These results demonstrate that opioids released in the NAcc during consumption of palatable foods produce a selective and transient increase in preference for a recently sampled flavor.

Nucleus accumbens dopamine release is necessary and sufficient to promote the behavioral response to reward-predictive cues.

The nucleus accumbens is part of the neural circuit that controls reward-seeking in response to reward-predictive cues. Dopamine release in the accumbens is essential for the normal functioning of this circuit. Previous studies have shown that injection of dopamine receptor antagonists into the accumbens severely impairs an animal's ability to perform operant behaviors specified by predictive cues. Furthermore, excitations and inhibitions of accumbens neurons evoked by such cues are abolished by inactivation of the ventral tegmental area, the major dopaminergic input to the accumbens. These results indicate that dopamine is necessary to elicit neural activity in the accumbens that drives the behavioral response to cues. Here we show that accumbens dopamine release is causal to the rats' reward-seeking behavioral response by demonstrating that dopamine in this structure is both necessary and sufficient to promote the appropriate behavioral response to reward-predictive cues.

Urethral calculi: presentation and management.

OBJECTIVE: To determine the occurrence, symptoms, treatment and outcome in patients with urethral stones. PATIENTS AND METHODS: Fifty-one consecutive patients with urethral calculi were assessed prospectively; all were male and one was an infant. RESULTS: Acute retention of urine occurred in 78% of patients, urethral anatomical pathology in 6% and posterior urethral calculi in 88%. The urethral stones, solitary in each patient, consisted of calcium oxalate in 86%, struvite in 6%, mixed stones in 4%, calcium phosphate in 2% and uric acid in 2%. A methodical approach to therapy was used which aimed to clearly define the circumstances in which a given procedure was used, and the resulting success rate. CONCLUSION: The common belief that most urethral calculi in patients in developing countries originate from the bladder does not seem to be generally applicable. Urethral anatomical pathology does not seem to be a necessary condition for most of these calculi.

Physicians' knowledge, attitude and practice towards erectile dysfunction in Saudi Arabia.

We aimed to test the knowledge, attitude and practice (KAP) of physicians towards erectile dysfunction in the Eastern province of Saudi Arabia. At a scientific meeting about erectile dysfunction, 159 physicians from both government and private sectors answered a 34-item questionnaire in private. The mean total KAP score for the group was below the expected standard of 60%. Male physicians scored significantly higher than females. Urologists scored the highest, followed by andrologists. Surprisingly, physicians with higher qualifications scored lower than those with intermediate qualifications and even less than general practitioners. Those who had practised for > or = 10 years scored better than those with < 10 years practice. The role of cardiologists in the diagnosis and management of erectile dysfunction is discussed.

Physicians' knowledge, attitude and practice towards erectile dysfunction in Saudi Arabia

We aimed to test the knowledge, attitude and practice [KAP] of physicians towards erectile dysfunction in the Eastern province of Saudi Arabia. At a scientific meeting about erectile dysfunction, 159 physicians from both government and private sectors answered a 34-item questionnaire in private. The mean total KAP score for the group was below the expected st and ard of 60%. Male physicians scored significantly higher than females. Urologists scored the highest, followed by and rologists. Surprisingly, physicians with higher qualifications scored lower than those with intermediate qualifications and even less than general practitioners. Those who had practised for >/= 10 years scored better than those with < 10 years practice. The role of cardiologists in the diagnosis and management of erectile dysfunction is discussed

A model cochlear partition involving longitudinal elasticity.

This paper addresses the issue of longitudinal stiffness within the cochlea. A one-dimensional model of the cochlear partition is presented in which the resonant sections are coupled by longitudinal elastic elements. These elements functionally represent the aggregate mechanical effect of the connective tissue that spans the length of the organ of Corti. With the plate-like morphology of the cochlear partition in mind, the contribution of longitudinal elasticity to partition dynamics is appreciable, though weak and nonlinear. If the elasticity is considered Hookian then the nonlinearity takes a cubic form. Numerical solutions are presented that demonstrate the compressive nature of the partial differential nonlinear equations and their ability to produce realistic cubic distortion product otoacoustic emissions. Within the framework of this model, some speculations can be made regarding the dynamical function of the phalangeal processes, the sharpness of active cochlear mechanics, and the propogation of pathology along the partition.

Anterior hypospadias. Is repair necessary with urination in a sitting or squatting position?

OBJECTIVE: To determine the chronic complication rate of anterior hypospadias repair and to explore whether the practice of placing the neomeatus at the tip of the penis should be applicable to all cases in our community where urination is in a sitting/squatting position. METHODS: Over a 10-year period commencing 1st September 1987, 312 patients had hypospadias repair of whom 72% had anterior hypospadias. The meatus was advanced to the tip of the penis in all repairs. The location of the meatus was also determined in 281 non-complaining men with a straight penis and normal sexual and reproductive functions. Following prior information that anterior hypospadias was not associated with sexual and reproductive dysfunction, 51 patients were given a choice between repair or no repair. RESULTS: Urethrocutaneous fistula occurred in 5% of patients, urethral stricture in 3% and meatal retraction in 3%, with 92% of patients having no complications. Forty six percent of non-complaining men had the meatus in locations other than the tip of the penis. Of 51 patients with the benefit of informed consent, 73% opted for no repair. CONCLUSION: Our results of anterior hypospadias repair compare favourably with those of other centers. Placement of the meatus at the tip of the penis for anterior hypospadias should not be applicable to all patients in this community where urination is in a sitting/squatting position. Before such repairs, an informed consent is warranted by making the patients and their parents aware of the non-association of sexual and reproductive disorders with these anomalies.

Unusual high presentation of torsion of testicular appendages.

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Effect of ambrein on smooth muscle responses to various agonists.

The pharmacological effects of ambrein (isolated from ambergris) on the contractile responses induced by some agonists in smooth muscle preparations were investigated. Ambrein in the concentration range of 10, 50 and 250 microg/ml decreased the spontaneous contraction of the isolated rabbit jejunum, rat uterus and guinea-pig vas deferens. Ambrein-induced antagonism to acetylcholine (Ach) in the guinea-pig ileum was abolished when the concentration of calcium chloride in the Tyrode's solution was increased to 5 mM/l. Furthermore, ambrein did not antagonise nicotine-induced contractions in the isolated rabbit jejunum or serotonin-induced contractions in the isolated guinea-pig ileum and vas deferens or the rat uterus. However, ambrein in the concentration range of 10, 50 and 250 microg/ml antagonised prostaglandins (PGs) E2, D2, F2alpha, and oxytocin-induced contractions in the rat uterus in vitro. Ambrein also antagonised (+/-) noradrenaline and (-) adrenaline-induced contractions in the isolated guinea-pig vas deferens. It is concluded that ambrein-induced non-selective dose-dependent antagonism to the effects of some agonists (Ach, adrenaline, noradrenaline, PGs and oxytocin) in some smooth muscles may be due to the ability of this compound to interfere with the mobilisation of extracellular Ca2+ required for muscular contractions induced by these agonists.

Hypoglycemic effect and protein nutritive quality of soy and methionine-supplemented whole durum pasta products.

New low cost, high-protein and high-fiber pasta products processed from whole durum meal (WD) solely, WD supplemented with 7% or 12% defatted soy flour (SF), or 12% SF plus 0.3% methionine were evaluated in comparison with the regular pasta made of pure durum semolina (DS). Their protein nutritive quality was biologically evaluated by rat growth studies using diets containing 9% protein, through the parameters: food efficiency ratio (FER), protein efficiency ratio (PER), net protein utilization (NPU), digestibility coefficient (DC) and biological value (BV). The original products were administered to diabetic hypercholesterolemic albino rats, (injected with alloxane) to study their effects on the levels of blood glucose and plasma lipid fractions. The results indicate that diets based on pasta made of WD supplemented with SE or SF plus methionine had superior protein quality and succeeded in supporting normal growth of rats in contrast to the diets based on pasta made of unsupplemented WD or DS. These assays demonstrated that the values of FER, PER, NPU and BV of WD-pasta increased with increasing SF supplementation. However, high-fiber pasta made of unrefined WD solely or with SF had lower DC values compared to that of the regular DS-pasta. DC values decreased as the added SF increased. Adding methionine evidently affected FER, PER, BV and NPU values. Administration of high-protein and high-fiber pasta samples made of WD solely, supplemented with SF or SF plus methionine significantly reduced the elevated blood glucose as well as plasma cholesterol and plasma lipid fractions in hypercholesterolemic diabetic rats. Overall, considering nutritional evaluation, protein cost as well as hypoglycemic and hypocholesterolemic effects the pasta composed of 12% SF-WD and supplemented with 0.3% methionine represented the best high-fiber; high-protein and high-quality product.

Protection by epicoprostanol against hyperglycemia and insulitis in normal and diabetic rats.

Epicoprostanol (3-alpha-hydroxy-5 beta-cholestanol) has been studied for its effects on blood glucose and plasma insulin levels in rodents. Epicoprostanol significantly induced hypoglycemia and increased insulin levels in rat blood plasma by 88% and 66% compared to that of control after 2 h and 4 h of acute treatment at 100 mg/kg dose. It also highly significantly lowered blood glucose levels in a dose dependent manner at 50, 100 and 200 mg/kg doses when administered to alloxan-rendered moderately diabetic rats after 120 and 240 min of treatment. Similarly, epicoprostanol, with the same dosage regimen, caused hypoglycemia in streptozotocin-induced severe diabetic rats, to a similar extent at the same time-points. However, the lowest dose (10 mg/kg) failed to produce a striking effect in either of the diabetic groups. In normoglycemic rats, plasma insulin levels were affected significantly after a single dose (100 mg/kg) of epicoprostanol. In contrast, diabetic animals suffering from insulitis showed a significant decline in hyperglycemia, strongly suggesting an insulin-like action of epicoprostanol. It seems likely that epicoprostanol acts through a mechanism other than hyperinsulinemia.

Effect of (-)-cathinone, a psychoactive alkaloid from khat (Catha edulis Forsk.) and caffeine on sexual behaviour in rats.

The effect of (-)-cathinone, caffeine and their combinations was studied on the sexual behaviour of male rats. Male sexual activities were assessed by recording the erectile responses (grooming of genitalis, yawning/stretching and homosexual mounting), in the absence of females. The copulatory behaviour was observed by caging males with receptive females brought into oestrus with s.c. injection of oestradiol benzoate and progesterone. The copulatory pattern of male rats (mounting, intromissions, ejaculations and refractory period) was recorded. The oral treatment of cathinone (5 mg kg-1 day-1), caffeine (50 mg kg-1 day-1) and their combinations for 15 days increased arousal (motivation) in male rats as evidenced by increased mounting performance and anogenital investigatory behaviour. However, erectile and ejaculatory responses, measured in the present study, showed no stimulant effect. It is conceivable from the present results that cathinone, the psychostimulant constituent of khat modified masculine pattern behaviour and caffeine also changed the effect of cathinone when administered concomitantly. However, our data provide no evidence that cathinone could be considered as an aphrodisiac.

A study of ambrein treatment for the evaluation of change in plasma biochemical parameters in rats.

Biochemical effects of acute and subacute treatments with ambrein were investigated in rats by measuring the total proteins, cholesterol, triglycerides, GOT, GPT and alkaline phosphatase in the blood plasma. Also, determinations of prothrombin time (PT), partial thrombin time (PTT), thrombin time (TT) and fibrinogen level were performed. Furthermore, changes in plasma electrolyte concentration were studied. Ambrein administered i.p. did not cause any toxic symptoms in the liver as revealed by the histology of the liver tissue both in acute and subacute treatments. Ambrein itself did not significantly affect the plasma protein, cholesterol, GOT and GPT profiles, but lowered alkaline phosphatase at high doses (50 and 250 mg/kg) after subacute treatment. Thus far, no specific pattern of action of ambrein in electrolyte control has been found. However, it increased PT, PTT and TT and decreased fibrinogen levels in both the acute and subacute studies, pointing towards its potential as an anticoagulant and antifibrinogenic agent.

Effect of ambrein, a major constituent of ambergris, on masculine sexual behavior in rats.

The effect of ambrein, a major constituent of ambergris, was studied on the sexual behavior of male rats. The rats were administered ambrein in doses of 100 and 300 mg/kg body weight. Male sexual activities were assessed by recording the erectile responses (penile erection) and homosexual mountings in the absence of female. The copulatory studies were carried out by caging males with receptive females brought into estrus with subcutaneous injections of estradiol benzoate and progesterone. The copulatory pattern of treated male rats (mountings, intromissions, ejaculations and refractory period), the pendiculations (yawns/stretches) and orientation activities towards females, the environment and themselves, were recorded. Ambrein produced recurrent episodes of penile erection, a dose-dependent, vigorous and repetitive increase in intromissions and an increased anogenital investigatory behavior, identifying the drug used in the present study as a sexual stimulant. It is conceivable from the present results that the ambrein-modified masculine sexual behavior in male rats supports the folk use of this drug as an aphrodisiac.

Laboratory induced resistance to praziquantel in experimental schistosomiasis.

To study the effect of praziquantel (PZQ) on successive generations of S. mansoni worms, infected mice were treated 6 weeks after infection with different doses of PZQ (300, 500 mg/kg.), the schistosome strain was originally obtained from an infected Egyptian patient. The eggs subsequently produced by worms that had survived the PZQ treatment were used to infect snails and mice of the following generations. The results were expressed as average number of worms and cure rates in comparison with control groups. It was found that the use of PZQ., especially in low subcurative dose may lead to the development of resistance to therapeutic dose of the drug in following generations.