Biology
Permanent URI for this collection
Browse
Recent Submissions
- ItemLeishmania: Probable genetic hybrids between species in Sudanese isolates(Academic Journals, 2011-06)
- ItemLeishmania donovani: Genetic diversity of isolates from Sudan characterized by PCR-based RAPD(Elsevier, 2010-03-25)Drug unresponsiveness in patients with visceral leishmaniasis (VL) is a problem in many endemic areas. This study aimed to determine genetic diversity of Leishmania donovani isolates from a VL endemic area in Sudan as a possible explanation for drug unresponsiveness in some patients. Thirty clinically stibogluconate (SSG)-sensitive isolates were made SSG-unresponsive in vitro by gradually increasing SSG concentrations. The sensitive isolates and their SSG-unresponsive counterparts were typed using mini-circle kDNA and categorized using PCR–RAPD. All the isolates were typed as L. donovani, the resulting PCR– RAPD characterization of the SSG-sensitive isolates gave three distinct primary genotypes while, the SSG-unresponsive isolates showed only a single band. L. donovani isolates from eastern Sudan are diverse; this probably resulted from emergence of new L. donovani strains during epidemics due to the pressure of widespread use of antimonials. In this communication the possible role of isolates diversity in antimonial unresponsiveness and the in vitro changing PCR–RAPD band pattern in SSG-unresponsive strains were discussed.
- ItemA review on SARS-CoV-2: the origin, taxonomy, transmission, diagnosis, clinical manifestations, treatment and prophylaxis(GSC Biological and Pharmaceutical Sciences, 2020-06-11)Coronavirus disease 19 (COVID-19) pandemic, caused by highly contagious SARS-CoV-2 that infects the respiratory system. COVID-19 started in Wuhan, south China, in December 2019, and spread to all other parts of the world. SARS-CoV-2 has +ssRNA genome (29,844bp) enclosed in an enveloped capsule (60 to 140 nm) and showing high genome homology (96%) with coronavirus of its potential natural reservoir Horseshoe bats. Two types of SARS-CoV-2 were detected: type L (70%) and type S (30%). SARS-CoV-2 spikes have very high binding affinity with all cells expressing ACE2 receptor. Nasal swabs and bronchoalveolar lavage samples were used by reverse transcriptase rtPCR for detection of SARS-CoV-2. ELISA can detect anti-SARS-CoV-2 IgM and IgG antibodies five days post infection. COVID-19 infection is confirmed by clinical signs and symptoms and CT thoracic images. Patients typically present with fever (87.3%), cough (58.1%), dyspnea (38.3%), muscle soreness or fatigue (35.5%), chest distress (31.2%) and expectoration (29.4%). The fatality rate of the infection approaches 7%. Hundreds of lungs micro clots were reported to occur causing heart failure and death. Fatal consequences were reported in older patients and those with chronic diseases. There is no specific medicine, but supportive treatment and anticoagulants are in use. Chloroquine and azithromycin have fatal consequences in 50% of patients, while Remdesivir did not show significant clinical or antiviral effects. Plasma convalescence clear the infection within three days. There is no vaccine for SARS-CoV-2 due to its mutations. Social isolation and countries lockdown measures exert catastrophic negative impact on health and economy worldwide.