Prooxidant effects of high dose ascorbic acid administration on biochemical, haematological and histological changes in Cavia porcellus (Guinea pigs): a Guinea pig experimental model.

Introduction: Ascorbic acid (AA) is a water-soluble vitamin that is well known for its antioxidant and immune-boosting properties. Owing to the wide-range application of AA in the treatment of numerous ailments and its sweet taste, it is usually abused i.e. overused. However, the effect of the abuse has rarely received attention. Therefore, this study was designed to assess the effect of oral administration of high-dose ascorbic acid on biochemical and haematological parameters as well as the effects on the kidney, liver and lungs. Methods: adult guinea pigs were divided into four (4) groups where group 1 served as the untreated control group and groups 2-4 were dosed with 29 mg, 662 mg and 1258 mg of ascorbic acid per day, respectively for 28 days. Results: the result revealed that administration of high dose ascorbic acid significantly (P<0.05) increased serum creatinine from 50.0 ± 7.09 (NC) to AA29- 73.8 ± 4.5, AA-662-89.7 ± 3.3 and AA1258- 79.9 ± 5.7mmol/L and urea levels in the treatment group AA-1258 -18.3 ± 0.5 µmol/L compared to the normal group (NC-2.15 ± 0.6 µmol/L). Disturbance in electrolyte balance was observed with a significant (P<0.05) increase in Na+ from NC- 131.3 ± 3.5 mmol/L to 135.7 ± 3.6 mmol/L in the AA-1258 treatment group, Cl- ( NC- 67.1 ± 1.6 mmol/L increased to AA29- 92.1 ± 0.83, AA662- 95.3 ± 1.3 and AA-1258- 95.6 ± 0.4 mmol/L), and Ca2+ (NC- 2.66 ± 0.03 to AA1258- 3.36 ± 0.03 mmol/L) and a significant (P<0.05) decrease in serum K+ in the AA29-5.0 ± 0.2, AA662-5.2 ± 0.3 and AA1258-5.6 ± 0.3 mmol/L treatment groups compared to the normal group 6.6 ± 0.3 mmol/L. There was also a significant (P<0.05) increase in the differential blood count in the animals with a significant (P<0.05) increase in red blood count ( NC-5.11 ± 0.13 ×106/µL to AA1258- 5.75 ± 0.11×106/µL ), haematocrit count (NC 39.90 ± 0.52% to AA-29-42.08 ± 0.24 and AA1258-46.13 ± 0.86%), white blood count (NC 10.15 ± 1.01 ×103/µL to AA1258- 15.18 ± 1.65×103/µL ), total lymphocytes (NC 3.5 ± 0.51×103/µL to AA29-5.28 ±0.43×103/µL), monocytes (NC 0.45 ± 0.07×103/µL to AA1258 0.80 ± 0.07×103/µL), eosinophils (NC 0.23 ± 0.03×103/µL to AA12580.40 ± 0.03×103/µL), basophils (NC0.68 ± 0.10×103/µL to AA12581.20 ± 0.10×103/µL) and neutrophil count (NC 4.73 ± 0.68×103/µL to AA1258 8.36 ± 0.71×103/µL). The histopathological indices indicate cellular necrosis in the AA662 and AA1258 treatment groups of the kidney and liver respectively compared to the normal control which has normal cells. Conclusion: high dose of ascorbic acid can therefore be suggested to cause damage to the cells by causing cellular necrosis as observed in the histopathology results and has effect on the blood cells as observed in the increase compared to the normal control, and the consequences are possibly triggered through inflammatory responses.

COVID-19 Vaccine Acceptance and Hesitancy in Health Care Workers in Somalia: Findings from a Fragile Country with No Previous Experience of Mass Adult Immunization.

Coverage of COVID-19 vaccines in Somalia remains low, including among health workers. This study aimed to identify factors associated with COVID-19 vaccine hesitancy among health workers. In this cross-sectional, questionnaire-based study, 1476 health workers in government and private health facilities in Somalia's federal member states were interviewed face-to-face about their perceptions of and attitudes toward COVID-19 vaccines. Both vaccinated and unvaccinated health workers were included. Factors associated with vaccine hesitancy were evaluated in a multivariable logistic regression analysis. Participants were evenly distributed by sex, and their mean age was 34 (standard deviation 11.8) years. The overall prevalence of vaccine hesitancy was 38.2%. Of the 564 unvaccinated participants, 39.0% remained hesitant. The factors associated with vaccine hesitancy were: being a primary health care worker (adjusted odds ratio (aOR) = 2.37, 95% confidence interval (CI): 1.15-4.90) or a nurse (aOR = 2.12, 95% CI: 1.05-4.25); having a master's degree (aOR = 5.32, 95% CI: 1.28-22.23); living in Hirshabelle State (aOR = 3.23, 95% CI: 1.68-6.20); not having had COVID-19 (aOR = 1.96, 95% CI: 1.15-3.32); and having received no training on COVID-19 (aOR = 1.54, 95% CI: 1.02-2.32). Despite the availability of COVID-19 vaccines in Somalia, a large proportion of unvaccinated health workers remain hesitant about being vaccinated, potentially influencing the public's willingness to take the vaccine. This study provides vital information to inform future vaccination strategies to achieve optimal coverage.

Mortality in COVID-19 patients after proximal femur fracture surgery: a systematic review and meta-analysis.

BACKGROUND: COVID-19 infection first emerged in December 2019 in China and has since rapidly spread to become a worldwide pandemic. Orthopaedic surgery suffered a significant decline in the volume of surgical cases, while the orthopaedic trauma services maintained or increased the activity. Emergency operations for proximal femur fractures (PFF) in the elderly population assumed levels comparable to before the pandemic, with the 1-year mortality rate ranging from 14% to 36%. AIMS: To determine whether patients with PFF affected by COVID-19 have a higher risk of postoperative mortality through a systematic review and meta-analysis. METHODS: PubMed, Web of Science, Scopus and BMC were searched from January 2020 to January 2021 to identify original studies reporting the mortality in COVID-19 patients after PFF surgery. Study and participants' characteristics, mortality rate and odds ratio (OR) were extracted. Risk of bias assessment was carried, and visual inspection of the funnel plot was used to assess publication bias. A random-effects model for meta-analysis was adopted. RESULTS: Among 656 articles that came from the search query and hand-search, 10 articles were eligible after applying inclusion and exclusion criteria. Overall, the sum of the study participants was 1882, with 351 COVID-19 positive patients (18.7%) and a total number of 117 deaths, with an overall mortality rate of 33.3%. The mortality rate of COVID-19 positive patients varied from 14.8% to 60% and was higher than of those without COVID-19, with OR ranging from 2.424 to 72.00. The inverse variance method showed an OR = 3.652. All studies showed a statistically significant p-value. CONCLUSIONS: The postoperative mortality in hip fracture patients with concomitant COVID-19 was 3.65 times higher than the mortality in non-COVID patients. The currently available literature demonstrates that COVID-19 infection represents a substantial risk factor for postoperative mortality in the already susceptible hip fracture population.

Drought, desertification and poverty: A geospatial analysis of snakebite envenoming in the Caatinga biome of Brazil.

Epidemiological data on snakebite in the Brazilian state of Ceará are scarce, as the only report on this subject was last published in 1997. However, according to the Brazilian system of recording disease incidents (Sistema de Informação de Agravos de Notificação [SINAN]), more than 13,000 snakebites have been registered since 2001 in the state of Ceará, making this disease an important public health issue. In the present study, we evaluate the influence of environmental changes, including drought and desertification, on the risk of snakebite envenoming in the Brazilian northeastern state of Ceará. We compare public data on snakebites from Brazilian Epidemiological Surveillance System (DATASUS), rainfall records, advanced desertification maps, pastures and socioeconomic information of the 184 municipals in Ceará between 2001 and 2017. During the period of investigation, 8,945 snakebites were recorded, the majority (93.8%) of which involved venomous snakes. Almost half of the municipals (48%) had 100 incidences or more per 100,000 inhabitants. Data collected also highlight month-to-month occurrences of snakebites, with trends to rise shortly after the onset of precipitation, peaking in July and then trending downward as rainfall decreases, reaching the lowest level in December. We deduce an inverse relationship between Human Development Index (HDI) and snakebites per area. Spearman correlation and principal component analysis support the hypothesis that water scarcity and desertification are linked to increased risk of snakebite envenoming. Our study indicates that besides poverty, dry and desertified areas represent risk factors associated with increased incidence of snakebite envenoming in the state of Ceará.

RNAi-mediated resistance to whitefly (Bemisia tabaci) in genetically engineered lettuce (Lactuca sativa).

RNA interference (RNAi)-based transgenic technologies have evolved as potent biochemical tools for silencing specific genes of plant pathogens and pests. The approach has been demonstrated to be useful in silencing genes in insect species. Here, we report on the successful construction of RNAi-based plasmid containing an interfering cassette designed to generate dsRNAs that target a novel v-ATPase transcript in whitefly (Bemisia tabaci), an important agricultural pest in tropical and sub-tropical regions. The presence of the transgene was confirmed in T0 and T1 generations of transgenic lettuce lines, segregating in a Mendelian fashion. Seven lines were infested with whiteflies and monitored over a period of 32 days. Analysis of mortality showed that within five days of feeding, insects on transgenic plants showed a mortality rate of 83.8-98.1%. In addition, a reduced number of eggs (95 fold less) was observed in flies feeding on transgenic lettuce plants than insects on control lines. Quantitative reverse transcription PCR showed decreased expression level of endogenous v-ATPase gene in whiteflies feeding on transgenic plants. This technology is a foundation for the production of whitefly-resistant commercial crops, improving agricultural sustainability and food security, reducing the use of more environmentally aggressive methods of pest control.

Sex-differences in the prevalence of Helicobacter pylori infection in pediatric and adult populations: Systematic review and meta-analysis of 244 studies.

BACKGROUND: The main outcome of Helicobacter pylori infection, i.e. gastric cancer, is more frequent in men, but there is no comprehensive synthesis of the evidence on a potential role of sex in the acquisition and/or persistence of infection. AIMS: To quantify the association between sex and H. pylori infection in pediatric and adult populations, through systematic review and meta-analysis. METHODS: PubMed® was searched, from inception to September 2015, to identify population-based studies reporting the prevalence and/or incidence of H. pylori infection in both sexes. Odds ratios (OR) or data to compute them were extracted; adjusted estimates were preferred, whenever available. The DerSimonian and Laird method was used to compute summary estimates and respective 95% confidence intervals (95%CI), separately for children and adults. RESULTS: Among a total of 244 studies, mostly cross-sectional, male sex was associated with a greater prevalence of H. pylori infection, both in children (102 studies, OR=1.06, 95%CI: 1.01, 1.12, I2=43.7%) and adults (169 studies, OR=1.12, 95%CI: 1.09, 1.15, I2=68.5%). An underrepresentation of studies showing a negative association between male sex and infection was observed (Egger's test: p=0.006). CONCLUSIONS: Although further research is needed to understand the mechanisms by which sex may influence the acquisition and/or persistence of infection, our results support a small contribution of sex differences in the prevalence of infection to the male predominance of H. pylori-related outcomes, including gastric cancer.

Synthesis, Characterization and Antibacterial Studies of N-(Benzothiazol-2-yl)-4-chlorobenzenesulphonamide and Its Neodymium(III) and Thallium(III) Complexes.

N-(Benzothiazol-2-yl)-4-chlorobenzenesulphonamide (NBTCS) was synthesized by condensation reaction of 4-chlorobenzenesulphonyl chloride and 2-aminobenzothiazole in acetone under reflux. Neodymium(III) and thallium(III) complexes of the ligand were also synthesized. Both ligand and metal complexes were characterized using UV-Vis, IR, ¹H- and 13C-NMR spectroscopies, elemental analysis and molar conductance measurement. IR studies revealed that the ligand is tridentate and coordinates to the metal ions through nitrogen and oxygen atoms of the sulphonamide group and nitrogen atom attached to benzothiazole ring. The neodymium(III) complex displays a coordination number of eight while thallium(III) complex displays a coordination number of six. The ligand and its complexes were screened in vitro for their antibacterial activities against Escherichia coli strains (E. coli 6 and E. coli 13), Proteus species, Staphylococcus aureus and Pseudomonas aeruginosa using the agar well diffusion technique. The synthesized compounds were found to be more active against the microorganisms screened relative to ciprofloxacin, gentamicin and co-trimoxazole.

BIOASSAY-GUIDED FRACTIONATION AND ANTIHYPERTENSIVE PROPERTIES OF FRACTIONS AND CRUDE EXTRACTS OF PERISTROPHE BICALYCULATA (RETZ) NEES.

Hypertension is an important public health issue in both developed and developing countries due to its high incidence and morbidity. This has motivated researchers especially in developing countries to search for strategies for the treatment using different plant parts. The use of the aqueous decoction of the leaves of Peristiophe bicalyculata in the treatment of hypertension has been documented. This study was designed to carry out a bioassay-guided isolation of the antihypertensive components of the leaves of Peristrophe bicalyculata in L-NAME hypertensive rats, determine the angiotensin-converting enzyme inhibitory activity of the extracts and fractions obtained and identify the constituent(s) present. From our results, L-NAME hypertensive rats given the cold water extract had significantly (p < 0.05) lower mean arterial blood pressure (MABP) with longer duration of action than other extracts. Also, the angiotensin-converting enzyme inhibitory activity of the cold water extract was significantly (p < 0.05) higher than that of other extracts. From the GC-MS analysis of the most effective fraction (fraction 4), P,P,P-triphenyl-imino(triphenyl)phosphorane and andrographolide 2(3H)-furanone were identified among others. The present work demonstrates the hypotensive effect of the cold water extract of Peiistiophe bicalyculata on L-NAME hypertensive rats, which further justifies the folkloric application of extracts of the plant in the management as well as treatment of hypertension.

RNAi-mediated resistance to viruses in genetically engineered plants.

RNA interference (RNAi) has emerged as a leading technology in designing genetically modified crops engineered to resist viral infection. The last decades have seen the development of a large number of crops whose inherent posttranscriptional gene silencing mechanism has been exploited to target essential viral genes through the production of dsRNA that triggers an endogenous RNA-induced silencing complex (RISC), leading to gene silencing in susceptible viruses conferring them with resistance even before the onset of infection. Selection and breeding events have allowed for establishing this highly important agronomic trait in diverse crops. With improved techniques and the availability of new data on genetic diversity among several viruses, significant progress is being made in engineering plants using RNAi with the release of a number of commercially available crops. Biosafety concerns with respect to consumption of RNAi crops, while relevant, have been addressed, given the fact that experimental evidence using miRNAs associated with the crops shows that they do not pose any health risk to humans and animals.

Anti-trypanosomal effect of Peristrophe bicalyculata extract on Trypanosoma brucei brucei-infected rats.

OBJECTIVE: To investigate the in vitro and in vivo effect of whole plant extracts of Peristrophe bicalyculata on Trypanosoma brucei brucei-infected rats. METHODS: THE EXPERIMENT WAS DIVIDED INTO TWO PHASES: In the first phase, the anti-trypanosomal activity of the hot water, cold water, methanol and butanol extracts of the whole plant were determined by incubating with Trypanosoma brucei brucei. The cold water extract was partially-purified and the anti-trypanosomal activity of the fractions determined. In the second phase, Trypanosoma brucei brucei-infected rats were treated with fraction 2c for nine days. Packed cell volume (PCV), high density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol (TC), triacylglycerol (TAG), aspartate aminotransferase, alanine aminotransferases (ALT), alkaline phosphatase (ALP), total and direct bilirubin levels were determined at the end of the experiment. RESULTS: Cold water extract immobilized 90% of the parasites after 60 min of incubation, and fraction 2c completely immobilized the parasites after 35 min. It significantly increased PCV in Trypanosoma brucei brucei-infected rats. Decreased TC, TAG, HDL and LDL levels of infected rats increased significantly when rats were treated with the fraction, while elevated levels of total bilirubin and ALT also decreased. The difference in urea, direct bilirubin and ALP was not significant when infected rats were compared to rats in other groups. CONCLUSIONS: The ability of the plant to ameliorate the infection-induced biochemical changes calls for detailed investigation of the potentials of the plant for antitrypanosomiasis drug delivery.

Genetic engineering in Cowpea (Vigna unguiculata): history, status and prospects.

In the last three decades, a number of attempts have been made to develop reproducible protocols for generating transgenic cowpea that permit the expression of genes of agronomic importance. Pioneer works focused on the development of such systems vis-à-vis an in vitro culture system that would guarantee de novo regeneration of transgenic cowpea arising from cells amenable to one form of gene delivery system or another, but any such system has eluded researchers over the years. Despite this apparent failure, significant progress has been made in generating transgenic cowpea, bringing researchers much nearer to their goal than thirty years ago. Now, various researchers have successfully established transgenic procedures for cowpea with evidence of inherent transgenes of interest, effected by progenies in a Mendelian fashion. New opportunities have thus emerged to optimize existing protocols and devise new strategies to ensure the development of transgenic cowpea with desirable agronomic traits. This review chronicles the important milestones in the last thirty years that have marked the evolution of genetic engineering of cowpea. It also highlights the progress made and describes new strategies that have arisen, culminating in the current status of transgenic technologies for cowpea.