Clinico-epidemiological Characteristics of Asymptomatic and Symptomatic COVID-19-Positive Patients in Bangladesh.

As of August 15, 2020, Bangladesh lost 3591 lives since the first Coronavirus disease 2019 (COVID-19) case announced on March 8. The objective of the study was to report the clinical manifestation of both symptomatic and asymptomatic COVID-19-positive patients. An online-based cross-sectional survey was conducted for initial recruitment of participants with subsequent telephone interview by the three trained physicians in 237 adults with confirmed COVID-19 infection in Bangladesh. The study period was 27 April to 26th May 2020. Consent was ensured before commencing the interview. Collected data were entered in a pre-designed case record form and subsequently analyzed by SPSS 20.0. The mean±SD age at presentation was 41.59±13.73 years and most of the cases were male (73.0%). A total of 90.29% of patients reside in urban areas. Among the positive cases, 13.1% (n=31) were asymptomatic. Asymptomatic cases were significantly more common in households with 2 to 4 members (p=0.008). Both symptomatic and asymptomatic patients shared similar ages of presentation (p=0.23), gender differences (p=0.30) and co-morbidities (p=0.11). Only 5.3% of patients received ICU care during their treatment. The most frequent presentation was fever (88.3%), followed by cough (69.9%), chest pain (34.5%), body ache (31.1%), and sore throat (30.1%). Thirty-nine percent (n=92) of the patients had co-morbidities, with diabetes and hypertension being the most frequently observed. There has been an upsurge in COVID-19 cases in Bangladesh. Patients were mostly middle-aged and male. Typical presentations were fever and cough. Maintenance of social distancing and increased testing are required to meet the current public health challenge.

Wound Coverage of Infected Open Fracture of Distal Third of Tibia by Distally Based Medial Hemi-Soleus Muscle Flap.

We conducted a study to evaluate the reliability of the medial hemi-soleus muscle flap for wound coverage of infected open fracture of distal third of tibia. Wound coverage of exposed lower third tibia and ankle region remains a difficult task. Muscle flaps are preferred for infected wounds especially where there are exposed bone, joint and/or tendons. Soleus muscle is a good option for local reconstruction. Soleus being the prime ankle plantar flexor and stabilizer of the ankle in ambulation cannot be sacrificed without significant morbidity. Soleus is a bipennate muscle with independent blood supply of each half. Using one half retains its important function, increases arc of rotation, and makes it easy to orientate for coverage of defect of any shape thus obviating the need for use of whole Soleus muscle flap. So, medial hemisoleus muscle flap is a superior option than the whole Soleus. This post-intervention prospective study which was descriptive in nature was conducted at department of Orthopedics, Community Based Medical College Hospital, Mymensingh, Bangladesh from January 2012 to December 2012. Ten patients with distal third tibial defects were included in the study. Data was obtained by history taking, observation, clinical examination, supported by routine laboratory and radiological investigations. Before intervention they underwent to careful vascular study of the affected limb through Doppler ultrasonography. All the patients were provided soft tissue coverage with distally based medial hemi-soleus muscle flaps with split thickness skin graft on it. All the flaps survived with primary healing of the wound. Among the participants there were 7 male and 3 female with average age 44.60 years, SD 13.73 years. Eight patients were injured by road traffic accident and 2 patients had history of alleged assault. The wound size defects in primary site ranged from 4cm to 9cm in length and 3cm to 6.5cm in breadth. All the wounds in the primary site were infected. The fractures in the primary site were open fractures involving distal third of tibia. In the secondary site the injuries were fracture upper third tibia in the other lower limb 2, fracture femur on other lower limb 1, dislocation shoulder joint on the same side upper limb 1. The follow up period ranged from 8-16 weeks (average 12 weeks). The outcome was successful. All flaps survived without complication. Hemisoleus muscle flap is a valuable local option for soft tissue coverage of distal third of leg. It does not sacrifice the whole soleus muscle. Due to its longer arc of rotation, this flap can cover the defect of different size and shape in distal third of leg.

Disease Pattern among Children attending Pediatric Outpatient Department in Community Based Medical College Hospital, Bangladesh.

Disease pattern is based on socio-demographic characteristics, comprehensive health care services, and environmental variables like water supply, basic sanitation and housing, illness behavior like quick decision to arrive at health care facility, and treatment behavior like the modality of treatment they receive. The descriptive cross-sectional study was conducted during the period of January 2014 to December 2015. The study was carried out among 310 purposively selected children attended at Pediatric Outpatient department of Community Based Medical College Hospital, Bangladesh. Data were collected by face to face interview of the parents and clinical examination and anthropometric measurement of children using case record form. Mean age of the children was 4.11 years with a SD of 4.35 years, male-female ratio was 1.25:1 with predominance 201(64.84%) of under-five children. The common diseases were 121(39.03%) with Acute Respiratory Infections (ARI), while 43(13.87%) diarrheal diseases, 25(8.06%) each with bronchial asthma and helminthiasis. Other diseases 96(30.97%) include anemia 17(5.48%), urinary tract infection 15 (4.84%), peptic ulcer disease 9(2.90%), enteric fever, oral candidiasis, apthous ulcer of mouth, scabies and vulvovaginitis. Average number of children per family was 2.2 including 251(80.97%) children having sanitary latrine in the family, 297(95.81%) with safe drinking water facilities and 270(87.10%) were fully vaccinated under EPI. More than three fourth 76(24.52%) of the children were underweight, 114(36.77%) were from poor families and 136(43.87%) lived in Kancha house. With the improvement of safe water supply and use of sanitary latrine diseases like diarrhoeal disease and helminthiasis are showing a decreasing trend.

Evaluation of outcome of surgical excision of the nidus of osteoid osteoma of long bone.

Osteoid osteoma is a benign bone tumour usually found in the lower extremities of children and young adults. This tiny bone tumour causes pain out of all proportion to its size and hinders the daily activities. This Quasi-experimental study conducted in the department of Orthopaedic surgery of BSMMU from January 2008 to December 2009. Twenty one patients were included in the study where purposive sampling technique was used on the basis of inclusion and exclusion criteria and all the ethical conditions were fulfilled. Diagnosis was almost obtained by taking history, clinical examination, and relevant investigations. Clinical variables were age, sex, site, pain, swelling, deformity and outcome variables were painless active life, removal of swelling, prevention of deformity, rate of recurrence. After localization of the tumour with the help of C arm, the nidus was excised in a small block of bone. The outcome is categorized by consensus, as clinically successful, only if the patient was free of pain and was taking no medication. The treatment was considered to have failed if a subsequent procedure had been performed to remove tumour. Among 21 cases, 14(66.7%) were male and 7(33.7%) were female. Maximum number of patients 15(71.4%) was between 10 years to 20 years. Most of the patients (76.2%) affected by osteoid osteoma were young students and most of the patients (95.2%) experienced moderate aching pain, usually aggravating at night which was typically relieved by aspirin or other NSAIDs (71.4%). Lower limbs (76.2%) particularly femur and tibia were commonly affected. Out of 21 patients, 19(90.5%) patients have got immediate pain relief or required no medication. In only 2 patients (9.5%), subsequent procedure has been performed to relief pain. So, successful outcome (in 19 out of 21) was significantly (p<0.001) higher in comparison to failed. Surgical excision of the nidus is a simple and easy procedure and does not require extensive resection of bone. If localization is done properly success rate is high and patients can return to normal daily activities.

Development of a groEL gene-based species-specific multiplex polymerase chain reaction assay for simultaneous detection of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus.

AIMS: To develop an effective multiplex polymerase chain reaction (PCR) for the simultaneous detection of three important Vibrio species, Vibrio cholerae (Vc), V. parahaemolyticus (Vp) and V. vulnificus (Vv) using the groEL gene, a potential phylogenetic marker. METHODS AND RESULTS: Three species-specific primer sets were designed to target Vc, Vp and Vv. A total of 131 Vibrio and non-Vibrio strains were used to determine the specificity and sensitivity of primers. The primers produced specific PCR fragments from all target species strains and did not cross-react with other Vibrio and non-Vibrio species. This PCR method showed good efficiency in detecting coexisting target species in the same sample with a detection limit of 100 pg of Vc, Vp and Vv from mixed purified DNA. Detection of three target species was also possible from artificially inoculated shellfish, flounder and sea water. CONCLUSIONS: The groEL gene is a potential marker for accurate simultaneous detection of Vc, Vp and Vv and could be used to detect these species in environmental and clinical samples. SIGNIFICANCE AND IMPACT OF THE STUDY: This newly developed multiplex PCR is a useful and cost-effective method that is applicable in a disease-outbreak prediction system and may provide an effective tool for both the epidemiologist and ecologist.

Application of groEL gene for the species-specific detection of Vibrio parahaemolyticus by PCR.

AIMS: Vibrio parahaemolyticus is a significant cause of human gastrointestinal disorders and is transmitted through ingestion of raw or undercooked contaminated seafood. We used the groEL gene for the species-specific detection of V. parahaemolyticus from artificially inoculated shellfish, fish and seawater. METHODS AND RESULTS: The nucleotide sequences of 24 Vibrio and seven non-Vibrio spp. were compared, and less conserved regions were selected for the designing of primer sets. To detect V. parahaemolyticus specifically, PCR conditions were standardized and tested to evaluate the specificity of primers. A 510-bp band was appeared only from V. parahaemolyticus by PCR. Notably, the detection was shown to be functional at high annealing temperature above 68°C. The groEL primers detected 100 pg and 1 ng of DNA purified from V. parahaemolyticus culture and artificially infected oyster tissue, respectively. CONCLUSIONS: The groEL gene is a potential marker for the species-specific detection of V. parahaemolyticus and could be used to detect this bacterium in contaminated food by PCR. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR using primers designed from groEL gene provide an efficient method for the accurate identification of V. parahaemolyticus from contaminated samples.

Evaluation of surgical management of primary spinal tumours.

Spinal tumours, which are 5-10% of skeletal tumours, cause considerable morbidity and present challenging situations in their management. Surgery is often used in the treatment of spinal tumours. Now a day only few specialized spinal care centers have developed in Bangladesh. The prospective study regarding surgical management of primary spinal tumour might be beneficial for proper planning and patient management. All patients who underwent surgical resection of a primary tumor of the spine between July 2006 and May 2008, at the Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Patients were uniformly staged before surgery and baseline demographic and surgical variables were recorded, as well as an evaluation of general health related quality of life were done. Thirty-two patients (16 males and 16 females) were eligible for the study. Average age was 43.25 (range 15 to 85). There were 8(25%) vertebral body and pedicle tumors and 3(9.37%) extradural, 16(50%) intradural-extramedullary and 05(15.67%) intradural intramedullary. Only 5(15.63%) developed complication. In this series out of 32 patients, 15(46.88%) achieved excellent result and 10(31.25%) got good result and 5(15.5%) achieved fair and remaining 2(6.25%) patients achieved poor results after the management. Complete neurological involvement of patient did not show complete recovery. In addition to surgery, radiotherapy and chemotherapy are needed to sterilize the tumour bed. Early detection and surgery of primary spinal tumour give satisfactory results and patient can return to their normal life.

Crystallographic studies on damaged DNAs IV. N( 4)-methoxycytosine shows a second face for Watson-Crick base-pairing, leading to purine transition mutagenesis.

To investigate the mutation mechanism of purine transitions in DNA damaged with methoxyamine, a DNA dodecamer with the sequence d(CGCAAATTmo(4)CGCG), where mo(4)C is 2'-deoxy-N(4)-methoxycytidine, has been synthesized and the crystal structure determined by X-ray analysis. The duplex structure is similar to that of the original undamaged B-form dodecamer, indicating that the methoxylation does not affect the overall DNA conformation. Electron density maps clearly show that the two mo(4)C residues form Watson-Crick-type base pairs with the adenine residues of the opposite strand and that the methoxy groups of mo(4)C adopt the anti conformation to N(3) around the C(4)-N(4) bond. For the pair formation through hydrogen bonds the mo(4)C residues are in the imino tautomeric state. Together with previous work, the present work establishes that the methoxylated cytosine residue can present two alternate faces for Watson-Crick base-pairing, thanks to the amino<-->imino tautomerism allowed by methoxylation. Based on this property, two gene transition routes are proposed.

Synthesis of bisbicyclo[1.1.1]pentyldiazene. The smallest bridgehead diazene.

Bisbicyclo[1.1.1]pentyldiazene, the smallest bicyclic azo compound, has been synthesized from the precursor [1.1.1]propellane via synthesis of N,N'-bis(bicyclo[1.1.1]pentyl)sulfamide and azoxybicyclo[1.1.1]pentane. The UV absorption of this diazene at 382 nm indicates that the compound is the trans isomer. Conversion to the cis isomer by irradiation was not possible because of attainment of a photostationary state. However, on the basis of the photochemical studies, the absorption of the cis-[1.1.1] isomer is estimated to be 384 nm.

Crystallographic studies on damaged DNAs: III. N(4)-methoxycytosine can form both Watson-Crick type and wobbled base pairs in a B-form duplex.

To investigate the mutation mechanism of purine transition in DNA damaged with methoxyamine, a DNA dodecamer with the sequence d(CGCGAATTmo(4)CGCG), where mo(4)C is 2'-deoxy-N(4)-methoxycytidine, has been synthesized and its crystal structure determined. Two dodecamers form a B-form duplex. Electron density maps clearly show that one of the two mo(4)C residues forms a pair with a guanine residue of the opposite strand, the geometry being the canonical Watson-Crick type, and that the other mo(4)C residue forms a wobble pair with the opposite guanine residue. These two pairings are ascribed to the tautomerization of the methoxylated cytosine moieties between the amino and imino forms.

X-ray analyses of two DNA dodecamers containing N4-methoxy-cytosine paired with adenine or guanine.

To investigate mismatch of base-pairings in relation to mutagenesis by oxyamines, crystal structures of two DNA dodecamers with the sequence d(CGCZAA TTmo4CGCG) (Z = A or G), containing N4-methoxy-cytosine (mo4C), have been determined by X-ray analysis. These dodecamers essentially form right-handed B-form duplexes, respectively. In the dodecamer with Z = A, the two mo4C residues are adapted in imino form with the anti methoxyl group to form pairs with A on the opposite strand in a manner of Watson-Crick fashion. While in the dodecamer with Z = G, one mo4C in amino form with the anti methoxyl group forms a normal Watson-Crick pair with G, but the other one in imino form with syn methoxyl conformation wobbles with G. Based on these results, possible mutation mechanism has been proposed.

X-ray analysis of a DNA dodecamer containing 2'-deoxy-N4-methoxycytidine.

The crystal structure of DNA dodecamer with the sequence of d(CGCAAATTXGCG), where X is 2'-deoxy-N4-methoxycytidine, has been determined by X-ray analysis. The dodecamers form a double helix with B-form conformation. The electron density indicates that the two modified cytosine bases respectively make a pair with the adenine bases on the opposite strand in a manner of Watson-Crick geometry and that the methoxy groups are in anti conformation to the N3 atom.