Glucose-6-phosphate dehydrogenase deficiency enhances Covid-19 infection in elderly people.

Our understanding of the mechanisms responsible for death of aged people from Covid-19 became one of the major concerns of these days. Glucose-6-phosphate dehydrogenase (G6PD) enhances the normal senescence and accelerates the precocious removal of chronologically young, yet biologically aged cells. Thus, its deficiency is associated with an increase in the cellular oxidative stress. Accumulating evidence showed that oxidative stress has a fundamental role in several age-related diseases. Nowadays, Covid-19 is considered a serious health problem worldwide. The host cellular environment is the key determinant of pathogen Infectivity. Most respiratory viral infections have a strong association with Glucose-6-phosphate dehydrogenase. Unfortunately, this enzyme deficiency markedly decreases with aging what is involved in increasing of the morbidity rate. The aim of this mini review was to shed more light on the role of G6PD deficiency in aged people infected with Covid-19 (Ref. 20). Keywords: GSPD, Covid-19, elderly people.

Mechanism of grape seeds extract protection against paracetamol renal cortical damage in male Albino rats.

OBJECTIVE: The aim of the study was to assess the possible protective role of grape seeds extract (GSE) in ameliorating the toxic effects of paracetamol overdose on the rat renal cortical tissue. BACKGROUND: Paracetamol is one of the widely used non-steroidal anti-inflammatory drugs (NSAIDs). Unfortunately, it was reported as the most common cause of toxic ingestion in the world. Grape seeds extract (GSE) is known to have a strong antioxidant and anti-inflammatory properties. METHODS: The rats were divided into 4 groups; control group, GSE group, paracetamol group and GSE with paracetamol group. Kidney specimens were processed for biochemical, histological and immunohisto-chemical studies. RESULTS: The study showed marked biological changes in the form of significant increase in serum urea and creatinine levels with significant decrease in renal superoxide dismutase with paracetamol group. Furthermore, Proximal (PCT) and distal convoluted tubules showed marked degeneration, dense nuclear staining, cytoplasmic vacuolization, and partial loss of the brush borders. Most tubules were dilated, irregular and were filled with hyaline casts. PCT and DCT showed less PAS reaction and more COX-2 and caspase expression if compared with the control and the GSE groups. Concomitant administration of grape seeds extract with paracetamol revealed a noticeable amelioration of these biochemical and histological changes. Proximal and distal convoluted tubules showed less PAS reaction and more COX2 and caspase expression if compared with the control and the GSE. Concomitant administration of GSE with paracetamol revealed a noticeable amelioration of these biochemical and histological changes. CONCLUSION: Grape seeds extract provided biochemical and histo-pathological improvement in paracetamol induced renal cortical toxicity. These findings revealed that this improvement was associated with a decrease in oxidative damage and apoptosis (Tab. 1, Fig. 7, Ref. 55).

Epizootiology of foot and mouth disease in Saudi Arabia: II. Current status on dairy farms and control measures in operation.

Specifically-designed questionnaires were distributed to the managers and/or veterinarians of all dairy farms in Saudi Arabia in order to obtain data on the occurrence of foot and mouth disease (FMD) on these farms from 1971 to 1989, as well as data on current control measures. Of 39 farms, 27 responded to the questionnaire and 15 (56%) reported FMD outbreaks. Notification and collection of samples for diagnosis were not performed consistently. Laboratory tests were undertaken at the World Reference Laboratory for Foot and Mouth Disease, Pirbright, United Kingdom. FMD virus serotypes O, A and C were isolated. Epizootiological factors contributing to the occurrence of FMD in Saudi dairy farms and recommendations for improving control of the disease are discussed in depth.

Serological survey of foot and mouth disease in Saudi Arabia.

An immunodiffusion test using foot and mouth disease (FMD) virus infection-associated (VIA) antigen was used to detect precipitating antibodies in serum samples collected from non-vaccinated indigenous ruminants raised in different regions of Saudi Arabia. Of 5,985 sheep sera, 1,371 goat sera, 1,052 cattle sera and 694 serum samples from unspecified species of ruminants, precipitating activity was detected in 1,209 (20%), 127 (9%), 172 (16%) and 38 (5%) samples, respectively. In addition, 100 sera showing precipitating activity against VIA antigen originating from 13 different regions were tested for the presence of naturally-occurring neutralising antibodies against the four serotypes of FMD virus (O, A, Asia 1, and C) currently prevalent in the region and incorporated in the vaccine being used. All sera tested gave varying titres against serotypes O, A and/or Asia 1. However, none of the sera showed neutralising activities against serotype C. The results obtained are interpreted with regard to the geographical distribution and epizootiology of FMD in Saudi Arabia.

Epizootiology of foot and mouth disease in Saudi Arabia: I. Analysis of data obtained through district field veterinarians.

Data on the epizootiological status of foot and mouth disease (FMD) in all districts of Saudi Arabia were obtained through responses to a specifically-designed questionnaire from field veterinarians working in different Directorates of Agriculture throughout the country. Suspected clinical occurrence of the disease was reported in seventeen of the twenty-three Directorates. The animal species affected were mainly cattle (in fifteen Directorates) and sheep (in eight Directorates). The disease was suspected among goats and camels in only two Directorates. Some animal owners were unwilling to notify suspicion of the disease. Laboratory diagnosis was not performed in all cases. Vaccination using an appropriately-formulated quadrivalent vaccine incorporating FMD virus serotypes O, A, C and Asia 1 was mainly applied to dairy animals. Limited numbers of locally-bred cattle and sheep were vaccinated in eight and four Directorates, respectively. The data obtained and the recommendations of field staff for improving control of FMD at the national level in Saudi Arabia are discussed.

Preliminary seromonitoring of rinderpest among cattle raised under different husbandry systems in Saudi Arabia.

Using the competitive enzyme-linked immunosorbent assay for the seromonitoring of rinderpest in Saudi Arabia, antibodies were detected in 30% of the sera of 1,018 cattle slaughtered at Riyadh abattoir during June and July 1995. The correlation between the detection of antibodies and the origins of the slaughtered animals was analysed. All the culled dairy cows had detectable antibodies. The proportions of bulls giving serologically positive results were as follows: 57% for animals imported from rinderpest-free countries and vaccinated upon arrival in Saudi quarantine, 20% for native breeding animals and 17% for five- to ten-month-old bull calves born on commercial dairy farms and then raised on separate feedlot farms. In addition, of 105 native cattle sacrificed during the Hajj season in May 1994, 77% had antibodies against rinderpest virus. On the other hand, testing of 17 groups of dairy heifers (from 1 week to 24 months of age), born to immune dams and vaccinated against rinderpest at the ages of six and ten months, revealed the absence of detectable antibodies in the sera of some animals which were between two and ten months of age. Results are interpreted in relation to evaluation of the continuing vaccination programmes and their efficacy as an element of the national programme for the control of rinderpest.

Preliminary studies on enzootic bovine leukosis in Saudi dairy farms.

The occurrence of sporadic cases of enzootic bovine leukosis in commercial dairy farms in Saudi Arabia was recently confirmed and found to be associated with importation of breeding heifers. Immunodiffusion test was applied to screen the prevalence of infection with bovine leukemia virus among local traditional and dairy cattle. All the 102 examined local cattle were negative, while out of the 1329 tested dairy animals (originating from 23 farms), 268 (from 16 farms) showed precipitating activity. As an epizootiological model, all animals of an infected dairy farm were serologically examined. Out of the 560 originally imported cows and the 1849 animals born locally in the farm, 217 (39%) and 468 (25%) animals, respectively, were found positive. The correlation between the age of locally born animals and the occurrence of antibodies against bovine leukemia virus was discussed.

The impact of live animal importation on the epizootiology of foot-and-mouth disease in Saudi Arabia.

Saudi Arabia imports annually more than 6 millions live ruminants for slaughter. The majority of these animals are imported from countries where foot-and-mouth disease (FMD) is enzootic. Serotypes of FMD virus not incorporated in the vaccine currently used in Saudi Arabia (e.g. SAT1 and SAT2) are prevalent in some of these exporting countries, and in others, the prevalent serotypes of FMD virus are not routinely typed. The previous exposure of imported animals to field FMD virus in the countries of origin has been confirmed by the detection of precipitating antibodies against virus infection associated (VIA) antigen and neutralizing antibodies against serotypes O, A, C and/or Asia1 of FMD virus in the sera of some imported animals. However, no isolation of FMD carrier virus could be made from 209 proband samples collected from sheep and goats imported from countries where FMD is enzootic. The significance of the obtained results is discussed. Particular emphasis has been placed on the possibility of importing either carrier animals which might act as potential source of infection or subclinically infected animals which might actively excrete FMD virus. In addition recommendations are made to reduce the risks of introducing exotic FMD virus strains to the Kingdom through live animal importation.

Application of double sandwich enzyme-linked immunosorbent assay for the diagnosis of foot-and-mouth disease in Saudi Arabia.

Using foot-and-mouth disease (FMD) diagnostic reagents provided by the FMD-World Reference Laboratory, Pirbright (United Kingdom), an indirect sandwich enzyme-linked immunosorbent assay (ELISA) was applied for local diagnosis of FMD in the Kingdom of Saudi Arabia. Testing epithelial tissues and/or vesicular fluids, it was possible to carry out serotyping of FMD virus before its isolation in cell cultures. All the field samples received as well as the oesophageal pharyngeal fluids collected from apparently healthy animals were inoculated onto primary bovine kidney cell cultures and the isolated FMD viruses then serotyped by ELISA. Testing of samples received from 43 outbreaks revealed positive FMD diagnosis in 29 outbreaks (27 caused by serotype "O" and 2 caused by serotype "A" of FMD virus). In addition, ELISA serotyping of 35 carrier strains of FMD virus (isolated from 286 proband samples) revealed 28 serotype "O" and 7 serotype "A" FMD viral isolates. The results are discussed concerning the importance of applying local FMD diagnosis and the current epizootiological status of the disease in Saudi Arabia.

Serotypes of bluetongue virus present in Saudi Arabia.

The widespread occurrence of infection with bluetongue virus (BTV) in Saudi Arabia has been demonstrated by immunodiffusion testing. Subsequently, 31 sheep sera and 1 goat serum with clear precipitating activity were examined by neutralization test using the 22 reference serotypes of BTV. Only 12 sheep sera neutralized 1 or more of BTV serotypes: 6 (1 serum), 14 (2 sera), 17 (4 sera), 19 (1 serum) and 20 (11 sera). The goat serum neutralized only serotype 19 of BTV. On the other hand, 19 sheep sera failed to neutralize any known BTV serotype. The significance of these serological findings was discussed and planning for further studies to isolate local BTV strains from sentinel flocks of lambs and calves was proposed.

Antigenic types of bluetongue virus prevalent in Egypt.

In an attempt to identify the antigenic types of bluetongue (BT) virus prevalent in Egypt 31 selected sheep sera from different parts of Egypt which had been screened by gel precipitation tests were examined by a plaque reduction test using 16 types of BT virus. Dilutions 1:5 of those screened sera reduced more than 50% of plaques of at least 1 of 16 types of BT virus. Two sera completely inhibited plaque formation with type 4 virus, 1 with type 13, another serum with type 15 and 2 other ser with type 16 virus. The significance of the above serological findings is discussed.

Serological evidence of the occurrence of bluetongue in Iraq.

Precipitating antibodies against bluetongue were detected in sheep and goat serum samples collected from animals slaughtered in Baghdad abattoir. Out of 294 sheep serum samples and 110 goat serum samples examined, 28 and 18 samples respectively showed precipitating activity. In addition, examination of sheep serum samples collected from localities where clinical cases similar to bluetongue were previously reported revealed the presence of bluetongue precipitating antibodies in 101 sera out of 198 samples examined. This is the first report confirming the occurrence of bluetongue in Iraq.

Studies on the methods of preparation of rinderpest hyperimmune sera in rabbits.

The procedures for the preparation of the rinderpest hyperimmune sera in rabbits were studied by comparing the sera from rabbits immunised by three different schedules of inoculations. The best sera for use in immunodiffusion tests were obtained from rabbits inoculated first with rinderpest hyperimmune serum and lapinised virus, and then with lapinised virus mixed with oil adjuvant twice at weekly intervals. Those rabbits which received additional one or two intravenous inoculations with lapinised virus yielded satisfactory sera for use in the diagnosis of rinderpest by immunodiffusion technique.

Molecular analysis of foot-and-mouth disease type O viruses isolated in Saudi Arabia between 1983 and 1995.

Partial nucleotide sequence of the capsid polypeptide coding gene 1D (VP1) was determined for 68 serotype O foot-and-mouth disease viruses isolated between 1983 and 1995 from outbreaks occurring in Saudi Arabia. The sequences were compared with previously published sequences: 14 viruses of Middle Eastern origin (isolated between 1987 and 1991); and with four vaccine virus strain sequences, three originating from the Middle East (O1/Turkey/Manisa/69, O1/Sharquia/Egypt/72 and O1/Israel/2/85) and one from Europe (O1/BFS 1860/UK/67). The virus isolates from Saudi Arabia and the Middle East vaccine virus strains formed a related genetic group distinct from the European O1 virus. Within this large group 12 distinct genetic sublineages were observed.

Analysis of mixed foot-and-mouth disease virus infections in Saudi Arabia: prolonged circulation of an exotic serotype.

Plaque purification of foot-and-mouth disease (FMD) type O viruses isolated from cattle in Saudi Arabia showed the presence of mixed serotype infections. Sixteen out of 31 samples collected between 1985 and 1991 also contained Asia 1 virus, a serotype which had previously only been isolated from a single outbreak in that country in 1980. Nucleotide sequences of the Asia 1 component of all these samples revealed little variation and showed that they were closely related to both a Russian lapinized vaccine virus strain (Asia 1/Tadzhikistan/64), and to a field isolate from Turkey (Asia 1/TUR/15/73). Although mixed FMD infections have been observed previously this is a first report of a serotype, considered to be exotic to a country, co-existing undetected for an extended period of time.

Experimental treatment of Brucella melitensis infection in sheep with oxytetracycline alone or combined with streptomycin.

The efficacy of oxytetracycline (OTC) alone or combined with streptomycin in the treatment of 118 Najdi ewes believed to have been naturally infected with Brucella melitensis, was evaluated by culture of selected tissues and organs at slaughter. Groups of sheep were given 250, 500 or 1,000 mg of OTC intraperitoneally (i/p) daily for six weeks and in the respective groups at necropsy 52, 69 and 100% of sheep were found to be Brucella-free. Treatment with 250 mg OTC (daily for six weeks i/p) combined with 1,000 mg streptomycin (daily for three weeks intramuscularly) increased the percentage of Brucella-free sheep to 82%. When a group of sheep were each inoculated i/p with 1,000 mg of long-acting OTC every three days over a period of six weeks, 75% of them were Brucella-free at necropsy. B. melitensis was isolated from all (24) non-treated (control) sheep. The results showed that long-term treatment with a high dose of OTC alone had succeeded in eliminating B. melitensis from a group of 16 naturally infected sheep.