Redox signalling in plant-nematode interactions: Insights into molecular crosstalk and defense mechanisms

Plant-parasitic nematodes, specifically cyst nematodes (CNs) and root-knot nematodes (RKNs), pose significant threats to global agriculture, leading to substantial crop losses. Both CNs and RKNs induce permanent feeding sites in the root of their host plants, which then serve as their only source of nutrients throughout their lifecycle. Plants deploy reactive oxygen species (ROS) as a primary defense mechanism against nematode invasion. Notably, both CNs and RKNs have evolved sophisticated strategies to manipulate the host's redox environment to their advantage, with each employing distinct tactics to combat ROS. In this review, we have focused on the role of ROS and its scavenging network in interactions between host plants and CNs and RKNs. Overall, this review emphasizes the complex interplay between plant defense mechanism, redox signalling and nematode survival tactics, suggesting potential avenues for developing innovative nematode management strategies in agriculture.

Different RT-PCR Protocol used in SARS-Cov2 PCR Laboratory of Mymensingh Medical College, Bangladesh

The novel corona virus (SARS CoV-2) was first detected on Wuhan, China. After that it spread worldwide and has caused many deaths till now. This virus is also known as novel corona virus because of being newly discovered. Scientifically it is named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has positive-single stranded RNA and several proteins such as spike (S), envelope (E), membrane (M), nucleocapsid (N) and the other helper proteins. On the basis of phylogenic evidence, it is the new member of beta corona viruses and this group of viruses causes respiratory illness in human. This virus is detected in laboratory by using RT-PCR, by which different target gene such as E gene, S gene, N gene and RdRP (ORF1a-ORF1b) etc. are detected. This study was carried out at Mymensingh Medical College from April 2020 to December 2020. Around 65000 samples (nasopharyngeal swab) were tested during this period by three PCR protocols. By Sansure PCR kit N and ORF1a target genes were detected, Basphore's target genes were E and ORF and by Neoplex PCR kit N and RdRp genes were detected. Most of samples were tested by Sansure kit (62500), 2000 samples were screened by Bosphore kit and 500 samples by Neoplex. Among them, 6876(11.0%) samples were positive by Sansure, 120(6.0%) by Bosphore and 66(13.2%) by Neoplex. Among the positive samples, N gene 6188(90.0%) was mostly found by Sansure kit, whereas ORF was 120(100.0%) mostly found by Bosphore.

Root architecture plasticity in response to endoparasitic cyst nematodes is mediated by damage signaling

Plant root architecture plasticity in response to biotic stresses has not been thoroughly investigated. Infection by endoparasitic cyst nematodes induces root architectural changes that involve the formation of secondary roots at infection sites. However, the molecular mechanisms regulating secondary root formation in response to cyst nematode infection remain largely unknown. We first assessed whether secondary roots form in a nematode density-dependent manner by challenging wild-type Arabidopsis plants with increasing numbers of cyst nematodes (Heterodera schachtii). Next, using jasmonate-related reporter lines and knockout mutants, we tested whether tissue damage by nematodes triggers jasmonate-dependent secondary root formation. Finally, we verified whether damage-induced secondary root formation depends on local auxin biosynthesis at nematode infection sites. Intracellular host invasion by H. schachtii triggers a transient local increase in jasmonates, which activates the expression of ERF109 in a COI1-dependent manner. Knockout mutations in COI1 and ERF109 disrupt the nematode density-dependent increase in secondary roots observed in wild-type plants. Furthermore, ERF109 regulates secondary root formation upon H. schachtii infection via local auxin biosynthesis. Host invasion by H. schachtii triggers secondary root formation via the damage-induced jasmonate-dependent ERF109 pathway. This points at a novel mechanism underlying plant root plasticity in response to biotic stress.

Relationship between Renal Function and Bone Mineral Density in Postmenopausal Women

Renal insufficiency is a risk factor for osteoporosis and can increase risk of fracture. It may be a result of an age-related decline in renal function or chronic kidney disease. In patients with CKD, accurate diagnosis of osteoporosis or CKD-MBD is important for determining the most appropriate treatment. This was a cross sectional study was done at Institute of nuclear medicine and Allied Sciences, BSMMU, Dhaka from 1st January 2014 to 31st December 2014. Study population was total 69 postmenopausal women age over 50 years. Women with Bilateral hip replacement or bilateral hip pins or screws, metallic rods in spine, Carrying out BMD scan within the week after other radiological investigation using contrast media e.g. Barium meals or enema, IVPs were excluded from study. Clinical variables were- age (years), height (cm), weight (kg), BMI. Laboratory variables were- serum creatinine and BMD (Dexa). Estimated GFR was determined by using the serum Creatinine by MDRD formula. Renal function test and Bone mineral density (BMD) were done in all of these patients. Majority (43.4%) of the patients were in 6th decade. The mean weight was found 57.4±11.2kg. Majority 41(59.4%) patients belonged to T score at hip (-1 to -2.5) and their mean T score at hip was found (-1.1±1.1). Osteopenia and osteoporosis were found in 59.4% and 4.3% respectively according to BMD. High serum creatinine level was found in 10.1% cases. Renal function impairment was found in 79.6% of patient. Majority (50.7%) patients had mild decrease of eGFR (60-89 ml/min/1.73m²), There was Pearson's correlation (r=0.156; p=0.200) but not significant was found between age with T score at hip of the patients. Positive Pearson's correlation (r=0.112; p=0.361) was found but not significant between age and serum creatinine level. A significant negative Pearson's correlation (r= -0.274; p=0.023) was found between T score at hip and serum creatinine level of the patients. A significant negative Spearman correlation (r=-0.278; p=0.021) was found between BMD and serum creatinine of the patients. A significant positive Spearman correlation (r=0.580; p=0.001) was found between BMD and estimated GFR of the patients. This study was undertaken to evaluate the relationship between renal function and bone mineral density in postmenopausal women. Majority of the postmenopausal women were in 6th decade and most of them were overweight and obese. Renal function impairment was found in 79.6% of patient. Osteoporosis was found in 04.3% and 20.3% cases according to T score at hip and T score at lumber spine respectively. Significant negative Pearson's correlation was found between T score at hip and serum creatinine level of the patients. Significant negative Spearman correlation was found between BMD and serum creatinine of the patients. Significant positive Spearman correlation was found between BMD and estimated GFR of the patients.

Distribution and Pattern of Anti-Tubercular Drug Resistance in Patients with Pulmonary Tuberculosis in Mymensingh Region of Bangladesh

Globally, the emergence of multidrug-resistant strains of Mycobacterium tuberculosis is an increasing problem that adversely affects patient care and public health. This cross sectional descriptive study was carried out in the Department of Microbiology, Mymensingh Medical College from January 2010 to December 2010 to isolate M. tuberculosis from smear-positive sputum samples by Lowenstein-Jensen (L-J) media and investigate the drug resistance pattern. Among 101 smear-positive cases 80(79.20%) yielded growth of Mycobacteria, 5(4.95%) were contaminated and 16(15.84%) showed no growth. Among 80 isolates 76(95.0%) were M. tuberculosis and the remaining 4(5.0%) were Non-tuberculous Mycobacteria (NTM). Out of 76 M. tuberculosis 27(35.52%) were resistant to at least one drug, 4(5.26%) to Isoniazid (INH), 1(1.32%) to Rifampicin (RMP), 8(10.53%) to Streptomycin (SM) and 0(0.0%) to Ethambutol (EMB) and multi-drug resistant tuberculosis (MDR-TB) was 9(11.84%). The present study creates the impression that fairly high rate of anti-tuberculosis drug resistance among the tuberculosis cases and also high MDR-TB (Resistant to both Rifampicin and Isoniazide). The emergence of MDR-TB poses significant trouble to TB control activities throughout the world. The complexity of MDR-TB operation makes it essential to produce new skills to design, plan, application and monitor interventions for the management of MDR-TB. More surveillance and immediate remedial interventions should be performed to combat the trouble of MDR-TB to the general population.

Glutathione contributes to plant defence against parasitic cyst nematodes

Cyst nematodes (CNs) are an important group of root-infecting sedentary endoparasites that severely damage many crop plants worldwide. An infective CN juvenile enters the host's roots and migrates towards the vascular cylinder, where it induces the formation of syncytial feeding cells, which nourish the CN throughout its parasitic stages. Here, we examined the role of glutathione (l-γ-glutamyl-l-cysteinyl-glycine) in Arabidopsis thaliana on infection with the CN Heterodera schachtii. Arabidopsis lines with mutations pad2, cad2, or zir1 in the glutamate-cysteine ligase (GSH1) gene, which encodes the first enzyme in the glutathione biosynthetic pathway, displayed enhanced CN susceptibility, but susceptibility was reduced for rax1, another GSH1 allele. Biochemical analysis revealed differentially altered thiol levels in these mutants that was independent of nematode infection. All glutathione-deficient mutants exhibited impaired activation of defence marker genes as well as genes for biosynthesis of the antimicrobial compound camalexin early in infection. Further analysis revealed a link between glutathione-mediated plant resistance to CN infection and the production of camalexin on nematode infection. These results suggest that glutathione levels affect plant resistance to CN by fine-tuning the balance between the cellular redox environment and the production of compounds related to defence against infection.

Clinical and Haematological Findings in Dengue Fever

From 2000 onwards dengue fever has been occurring at regular intervals in Bangladesh. Ultrasonography is a useful diagnostic procedure. This study was done, keeping this background in mind. Objective of this study was to identify the role of ultrasonography as a useful tool in early diagnosis of dengue haemorrhagic fever. This was a cross-sectional descriptive type of observational study. Results of ultrasonography, haematogy an immunology were observed in 2004 and 2019 in 32 patients on each occasion. In 2004 out of 32 patients 29 had positive ultrsonographic findings supported by corresponding haematological and immunological findings. In 2019 ultrsonography was done in three out of thirty two patients, all three had had positive ultra sonographic findings which were supported by haematological and immunological findings. Dengue fever has serious complications like plasma leakage which manifest in the form of ascites, pleural effusion, thick gallbladder wall etc. If such complications can be detected at an early stage many lives can be saved.

Pre-operative Halo-Pelvic Traction for Neurofibromatosis Patients with Severe Proximal Thoracic Spinal Deformity: Indications and Early Treatment Outcome

Introduction:

To report the indications and early treatment outcomes of pre-operative halo-pelvic traction in patients with neurofibromatosis associated with severe proximal thoracic (PT) spinal deformity.

Materials and methods:

We reviewed four patients with neurofibromatosis with severe PT spinal deformity. Case 1, a 16-year-old male presented with severe PT kyphoscoliosis (scoliosis: 89°, kyphosis: 124°) and thoracic myelopathy. Case 2 was a 14-year-old, skeletally immature male who presented with a PT lordoscoliosis (scoliosis: 85°). Case 3, a 13-year-old male, presented with severe PT kyphoscoliosis (scoliosis: 100°, kyphosis: 95°). Case 4, a 35-year-old gentleman, presented with severe PT kyphoscoliosis (scoliosis: 113°, kyphosis: 103°) and thoracic myelopathy. All patients underwent pre-operative halo-pelvic traction. After a period of traction, all patients underwent posterior spinal fusion (PSF) with autologous bone grafts (local and fibula bone grafts) and recombinant human bone morphogenetic protein-2 (rhBMP-2).

Results:

Both patients with thoracic myelopathy regained near normal neurological status after halo-pelvic traction. Following traction, the scoliosis correction rate (CR) ranged from 18.0% to 38.9%, while the kyphosis CR ranged from 14.6% to 37.1%. Following PSF, the scoliosis CR ranged from 24.0% to 58.8%, while the kyphosis CR ranged from 29.1% to 47.4%. The total distraction ranged from 50-70mm. Duration of distraction ranged from 26-95 days. The most common complication encountered during halo-pelvic traction was pin-related e.g. pin tract infection, pin loosening and migration, osteomyelitis, and halo-pelvic strut breakage. No patients had cranial nerve palsies or neurological worsening.

Conclusion:

Pre-operative correction of severe PT spinal deformities could be performed safely and effectively with the halo-pelvic device prior to definitive surgery.

Plant parasitic cyst nematodes redirect host indole metabolism via NADPH oxidase-mediated ROS to promote infection

Reactive oxygen species (ROS) generated in response to infections often activate immune responses in eukaryotes including plants. In plants, ROS are primarily produced by plasma membrane-bound NADPH oxidases called respiratory burst oxidase homologue (Rboh). Surprisingly, Rbohs can also promote the infection of plants by certain pathogens, including plant parasitic cyst nematodes. The Arabidopsis genome contains 10 Rboh genes (RbohA-RbohJ). Previously, we showed that cyst nematode infection causes a localised ROS burst in roots, mediated primarily by RbohD and RbohF. We also found that plants deficient in RbohD and RbohF (rbohD/F) exhibit strongly decreased susceptibility to cyst nematodes, suggesting that Rboh-mediated ROS plays a role in promoting infection. However, little information is known of the mechanism by which Rbohs promote cyst nematode infection. Here, using detailed genetic and biochemical analyses, we identified WALLS ARE THIN1 (WAT1), an auxin transporter, as a downstream target of Rboh-mediated ROS during parasitic infections. We found that WAT1 is required to modulate the host's indole metabolism, including indole-3-acetic acid levels, in infected cells and that this reprogramming is necessary for successful establishment of the parasite. In conclusion, this work clarifies a unique mechanism that enables cyst nematodes to use the host's ROS for their own benefit.

Factors Affecting Morbidity and Mortality after ERCP for Obstructive Jaundice

Endoscopic Retrograde Cholangio Pancreaticography (ERCP) is an invasive procedure which can be used for therapeutic purpose. But it has versatile complications. It depends upon patient factors and gastroenterologist's expertise. This study was done to determine factors affecting morbidity and mortality after ERCP for obstructive jaundice. The prospective observational study was conducted among 30 patients with obstructive jaundice in the department of Gastroenterology and Surgery of Combined Military Hospital (CMH), Dhaka during the period of July 2016 to December 2016. After obtaining a detailed history, general physical and systemic examinations were done for all enrolled patients and they were subjected to do relevant investigations. The data were collected by the active participation of the patient and patient was interviewed by the preformed case record form. ERCPs were carried out in a standard fashion by using a side viewing duodenoscope. Every variable like number of pancreatic duct cannulation, sphincterotomy, whether pre-cut or wire guided cannulation, number of failed removal of CBD stone and incomplete drainage was recorded by a trained assistant. The data analysis of 30 patients yielded that mean age of patient was 43.8 years. Most of the patients (50.0%) were in 41-60 years of age group. Among the respondents, 90.0% were male and 10.0% were female. The most common indication of ERCP was sphincterotomy with stone extraction (66.7%). About one tenth of study patients, 3(10.0%) developed post ERCP complications. The most common post ERCP complications were intra-procedural bleeding (66.7%) followed by pancreatitis (33.3%). Both of the complications were in mild form. In multivariate analysis it was found that history of acute pancreatitis, suspected SOD, needle knife and supra-papillary fistulotomy had more risks. Three (10.0%) patients developed complications, among which 66.7% had intra-procedural bleeding and 33.3% had pancreatitis. Middle aged person, male gender, precut sphincterotomy and history of acute pancreatitis are the commonest significant post ERCP morbidity and mortality predictors.

Depression among Medical Students of Bangladesh

Now a days depression is one of the leading cause of disabilities all over the world. Depression leads to a wide range of disorders and affects people of all communities. Medical students pass through a relatively high level of stress. Several studies revealed that anxiety and depression is significantly prevalent among medical students and often it persists even when they become physicians. The study was designed with an aim to estimate the prevalence of depression among the medical students of Bangladesh. The cross sectional descriptive type of observational study was conducted among randomly selected 399 Bangladeshi students of third year MBBS from six (6) randomly selected public medical colleges of Bangladesh from February 2017 to July 2017. Data were collected by a semi-structured self-administered questionnaire containing Beck's Depression Inventory. Data were entered and analyzed by SPSS version 20.0. Among 399 medical students, 45.6% were male and 54.4% were female. Regarding presence of depression among the medical students, 35.8% students had normal score. More than one fourth of the students (25.1%) had mild mood disturbance. Borderline clinical depression was found in 15.5% and moderate depression was found in 18.0% of the students. Severe depression was found in 5.3% students and one (0.3%) student was suffering from extreme depression. Overall 39.1% students were suffering from different levels of depression. Depression was prevalent more in female students (45.6%) than male students (31.3%). Suicidal tendency was present in 18.8% students. Among them 14.3% had thoughts of killing themselves but they would not carry them out; 3% would like to kill themselves and 1.5% would kill themselves if they had the chance. Suicidal tendency was also a bit higher in female students (19.3%) than male students (18.1%). A significant number (39.1%) of medical students of Bangladesh are suffering from depression and many of them (18.8%) have suicidal tendency which demands immediate attention of the authority. The findings of the study warrant a need for psychiatric counseling and support services for vulnerable students.

The anatomical locations of postoperative pain and their recovery trajectories following Posterior Spinal Fusion (PSF) surgery in Adolescent Idiopathic Scoliosis (AIS) patients

INTRODUCTION

This study looked into the different anatomical locations of pain and their trajectories within the first two weeks after Posterior Spinal Fusion (PSF) surgery for Adolescent Idiopathic Scoliosis (AIS).

METHODS

We prospectively recruited patients with Adolescent Idiopathic Scoliosis (AIS) scheduled for PSF surgery. The anatomical locations of pain were divided into four: (1) surgical wound pain; (2) shoulder pain; (3) neck pain; and (4) low back pain. The anatomical locations of pain were charted using the visual analogue pain score at intervals of 12, 24, 36, 48 hours; and from day-3 to -14. Patient-controlled analgesia (morphine), use of celecoxib capsules, acetaminophen tablets and oxycodone hydrochloride capsule consumption were recorded.

RESULTS

A total of 40 patients were recruited. Patients complained of surgical wound pain score of 6.2±2.1 after surgery. This subsequently reduced to 4.2±2.0 by day-4, and to 2.4±1.3 by day-7. Shoulder pain scores of symptomatic patients peaked to 4.2±2.7 at 24 hours and 36 hours which then reduced to 1.8±1.1 by day-8. Neck pain scores of symptomatic patients reduced from 4.2±1.9 at 12 hours to 1.8±1.1 by day-4. Low back pain scores of symptomatic patients reduced from 5.3±2.3 at 12 hours to 1.8±1.1 by day- 12.

CONCLUSIONS

Despite the presence of different anatomical locations of pain after surgery, surgical wound was the most significant pain and other anatomical locations of pain were generally mild. Surgical wound pain reduced to a tolerable level by day-4 when patients can then be comfortably discharged. This finding provides useful information for clinicians, patients and their caregivers.

Risk Factors for Hypertension in Young Adults of Bangladesh

Hypertension is a major public health challenge to population in socio-economic and epidemiological transition. It is a risk factor for cardiovascular mortality which accounts for 20-50 per cent of all deaths. Hypertension has been recognized among young adults more frequently in recent years. Data regarding hypertension in Bangladesh is often insufficient. The purpose of the study was to find out the risk factors of hypertension in young adults of Bangladesh. The study was conducted among 322 purposively selected young adults aged 20 to 49 years attending in the outpatient department of one public and five private hospitals of Mymensingh and Dhaka division of Bangladesh during the period of January 2018 to December 2018. More than half (54.4%) of the patients were at or below the age of 40 years. Mean age of the patients was 38.7±7.8 years and 58.7% were male. Maximum patients (87.6%) were married and with variable educational and occupational status. More than three fourth of the patients (76.7%) were from urban area whereas 14.3% from rural and 9.0% were from sub-urban area. Family history of hypertension was positive in 86.6% of patients. Blood pressure was categorized according to JNC 7. About half (49.4%) of the patients were stage I hypertensive; 22.4% were stage II hypertensive and 28.3% were pre-hypertensive. The major risk factor was tobacco smoking (46.0%), obesity (29.2%), dyslipidaemia (25.2%), high salt intake 21.8% and use of chewable tobacco (13.7%). Serum creatinine was found raised in 11.5%, cardiomegaly in 2.2% and concentric left ventricular hypertrophy in 18.6% of patients. In 38.5% patients hypertension was complicated affecting heart (27.0%) and kidney (11.5%). Common comorbidities were ischaemic heart diseases (20.5%) and diabetes mellitus (13.4%). Tobacco use, obesity, dyslipidaemia and high salt intake are the major modifiable risk factors found in hypertensive young adults. In addition to medication these factors should be addressed for prevention and effective control of hypertension.

Single-cell damage elicits regional, nematode-restricting ethylene responses in roots

Plants are exposed to cellular damage by mechanical stresses, herbivore feeding, or invading microbes. Primary wound responses are communicated to neighboring and distal tissues by mobile signals. In leaves, crushing of large cell populations activates a long-distance signal, causing jasmonate production in distal organs. This is mediated by a cation channel-mediated depolarization wave and is associated with cytosolic Ca²⁺ transient currents. Here, we report that much more restricted, single-cell wounding in roots by laser ablation elicits non-systemic, regional surface potential changes, calcium waves, and reactive oxygen species (ROS) production. Surprisingly, laser ablation does not induce a robust jasmonate response, but regionally activates ethylene production and ethylene-response markers. This ethylene activation depends on calcium channel activities distinct from those in leaves, as well as a specific set of NADPH oxidases. Intriguingly, nematode attack elicits very similar responses, including membrane depolarization and regional upregulation of ethylene markers. Moreover, ethylene signaling antagonizes nematode feeding, delaying initial syncytial-phase establishment. Regional signals caused by single-cell wounding thus appear to constitute a relevant root immune response against small invaders.

Growth performance of local and genetically improved chicken of Bangladesh

The experiment was conducted to compare the growth performance among four genotypes of indigenous chicken namely Non-descriptive Native (ND), genetically Improved Native (IN), Hilly (HC) and Naked Neck (NN) of Bangladesh under free-range rearing system.  A total of 288 day old chicks (DOC) from four genotypes were divided into four treatments having eight replications of each for a period of 12 weeks under free-range system with supplementation of commercial broiler diet. During first 4 weeks, all chicks were kept together, whereas chicks of ND was brooded in the same room but separated by a partition. At 5 weeks of age chicks were randomly distributed to the selected farmers. Growth parameters were recorded to determine the comparative growth performance among four genotypes of chicken. The highest body weight (1110.76 g/bird) was achieved by HC, followed by IN (900.63 g/bird) and NN (831.13 g/bird) at 12 weeks of age. The lowest body weight (734.13 g/bird) however was found in ND chicken. During the growing period under free range rearing (5-12 weeks), HC group consumed the highest amount of feed (2697.02 g/bird) with an average FCR of 3.06 while the lowest feed consumption (2666.13 g/bird) with the highest FCR of 4.90 was observed in ND. IN consumed (2674.63 g/bird) feed with an average FCR of 3.92 and BLRI improved NN consumed (2668.13 g/bird) feed with an average FCR of 4.19. Live weight gains in all the four genotypes of indigenous chicken were changed almost in a similar pattern. Significant differences were observed in live weight, dressing percentage, breast meat, drumstick, thigh meat among the four genotypes of chicken. The HC was superior to other genotypes of indigenous chicken including ND in terms of growth performance, meat yield characteristics and net returns. Bang. J. Anim. Sci. 2018. 47 (2):76-84

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.

Role of Liver Biopsy in the Diagnosis of Neonatal Cholestasis due to Biliary Atresia

Biliary atresia is the commonest cause of cholestatic jaundice. Early diagnosis & surgical correction helps long time survival & prevent development of cirrhosis. This study was conducted to find out the role of liver biopsy in the diagnosis of biliary atresia having positive hepatobiliary scintigraphy as there is chance of false positivity. This cross sectional study was carried out in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh at Paediatric Gastroenterology & Nutrition Department from January 2014 to June 2015. All admitted patients with the diagnosis of neonatal cholestasis were evaluated clinically and by scintigraphy for biliary atresia. Having positive hepatobiliary scintigraphy but highly suggestive of biliary atresia were enrolled for this study. A total of 108 cases were initially selected. Among them 33 patients showed no excretion of tracer during hepatobiliary scintigraphy. Liver biopsy was done in these 33 cases. All cases (100%) had history of passage of pale or acholic stool. Fractionated serum bilirubin of >2mg/dl was found all of the cases. Histological scoring system reveals typical features of biliary atresia in 27(81.8%). Two had no conclusive histology of biliary atresia, four had features of neonatal hepatitis (12.1%). In this study, percutaneous liver biopsy with histological analysis by scoring system was found useful for the correct diagnosis of biliary atresia.

Genome-wide association study uncovers a novel QTL allele of AtS40-3 that affects the sex ratio of cyst nematodes in Arabidopsis

Plant-parasitic cyst nematodes are obligate sedentary parasites that infect the roots of a broad range of host plants. Cyst nematodes are sexually dimorphic, but differentiation into male or female is strongly influenced by interactions with the host environment. Female populations typically predominate under favorable conditions, whereas male populations predominate under adverse conditions. Here, we performed a genome-wide association study (GWAS) in an Arabidopsis diversity panel to identify host loci underlying variation in susceptibility to cyst nematode infection. Three different susceptibility parameters were examined, with the aim of providing insights into the infection process, the number of females and males present in the infected plant, and the female-to-male sex ratio. GWAS results suggested that variation in sex ratio is associated with a novel quantitative trait locus allele on chromosome 4. Subsequent candidate genes and functional analyses revealed that a senescence-associated transcription factor, AtS40-3, and PPR may act in combination to influence nematode sex ratio. A detailed molecular characterization revealed that variation in nematode sex ratio was due to the disturbed common promoter of AtS40-3 and PPR genes. Additionally, single nucleotide polymorphisms in the coding sequence of AtS40-3 might contribute to the natural variation in nematode sex ratio.

A prospective international observational prevalence study on prone positioning of ARDS patients: the APRONET (ARDS Prone Position Network) study

INTRODUCTION

While prone positioning (PP) has been shown to improve patient survival in moderate to severe acute respiratory distress syndrome (ARDS) patients, the rate of application of PP in clinical practice still appears low.

AIM

This study aimed to determine the prevalence of use of PP in ARDS patients (primary endpoint), the physiological effects of PP, and the reasons for not using it (secondary endpoints).

METHODS

The APRONET study was a prospective international 1-day prevalence study performed four times in April, July, and October 2016 and January 2017. On each study day, investigators in each ICU had to screen every patient. For patients with ARDS, use of PP, gas exchange, ventilator settings and plateau pressure (Pplat) were recorded before and at the end of the PP session. Complications of PP and reasons for not using PP were also documented. Values are presented as median (1st-3rd quartiles).

RESULTS

Over the study period, 6723 patients were screened in 141 ICUs from 20 countries (77% of the ICUs were European), of whom 735 had ARDS and were analyzed. Overall 101 ARDS patients had at least one session of PP (13.7%), with no differences among the 4 study days. The rate of PP use was 5.9% (11/187), 10.3% (41/399) and 32.9% (49/149) in mild, moderate and severe ARDS, respectively (P = 0.0001). The duration of the first PP session was 18 (16-23) hours. Measured with the patient in the supine position before and at the end of the first PP session, PaO₂/F_IO₂ increased from 101 (76-136) to 171 (118-220) mmHg (P = 0.0001) driving pressure decreased from 14 [11-17] to 13 [10-16] cmH₂O (P = 0.001), and Pplat decreased from 26 [23-29] to 25 [23-28] cmH₂O (P = 0.04). The most prevalent reason for not using PP (64.3%) was that hypoxemia was not considered sufficiently severe. Complications were reported in 12 patients (11.9%) in whom PP was used (pressure sores in five, hypoxemia in two, endotracheal tube-related in two ocular in two, and a transient increase in intracranial pressure in one).

CONCLUSIONS

In conclusion, this prospective international prevalence study found that PP was used in 32.9% of patients with severe ARDS, and was associated with low complication rates, significant increase in oxygenation and a significant decrease in driving pressure.

Impact of salt-induced toxicity on growth and yield-potential of local wheat cultivars: oxidative stress and ion toxicity are among the major determinants of salt-tolerant capacity

High salinity is a major constraint for wheat productivity in many countries, including Bangladesh. Here, we examined the effects of salt-induced toxicity on growth and production of 10 local wheat cultivars by analyzing physiological, biochemical and agronomical responses to identify the salt-tolerant attributes among the contrasting genotypes. Results of cluster analyses based on salt tolerance indices of plant growth-related and yield-contributing parameters, ionic balance (Na⁺, K⁺ and Na⁺/K⁺ ratio), and stress indicators (SPAD values and proline) revealed Gourab and Shatabdi as salt-sensitive, BARI Gom 27 and 28 as salt-tolerant and the other six examined varieties as moderately salt-tolerant cultivars. Hierarchical clustering and principle component analyses also demonstrated BARI Gom 27 and 28 as the highest salt-tolerant cultivars, especially in terms of Na⁺/K⁺ ratio and proline level. Additionally, lower accumulations of hydrogen peroxide and malondialdehyde, and higher activities of antioxidant enzymes catalase, peroxidase and ascorbate peroxidase in the salt-tolerant BARI Gom 28 than in the salt-sensitive Gourab indicated reduced oxidative damage in BARI Gom 28 relative to that in Gourab. Collectively, our findings suggest that the optimum growth and yield of salt-tolerant cultivars are associated with decreased Na⁺/K⁺ ratio, increased proline level and reduced oxidative stress. Furthermore, BARI Gom 27 and 28 could be suggested as suitable cultivars for cultivation in salt-affected areas, and the contrasting salt-responsive genotypes can be used as valuable genetic resources in breeding and dissection of molecular mechanisms underlying wheat adaptation to high salinity.

Antifilarial activity of caffeic acid phenethyl ester on Brugia pahangi in vitro and in vivo

Lymphatic filariasis (LF) is a vector borne disease caused by parasitic worms such as Wuchereria bancrofti, Brugia malayi and B. timori, which are transmitted by mosquitoes. Current therapeutics to treat LF are mainly microfilarcidal, and lack activity against adult worms. This set back, poses a challenge for the control and elimination of filariasis. Thus, in this study the activities of caffeic acid phenethyl ester (CAPE) against the filarial worm B. pahangi and its bacterial endosymbiont, Wolbachia were evaluated. Different concentrations (2, 5, 10, 15, 20 μg/ml) of CAPE were used to assess its effects on motility, viability and microfilarial (mf) production of B. pahangi in vitro. Anti-Wolbachial activity of CAPE was measured in worms by quantification of Wolbachial wsp gene copy number using real-time polymerase chain reaction. Our findings show that CAPE was found to significantly reduce adult worm motility, viability, and mf release both in vitro and in vivo. 20 μg/ml of CAPE halts the release of mf in vitro by day 6 of post treatment. Also, the number of adult worms recovered in vivo were reduced significantly during and after treatment with 50 mg/kg of CAPE relative to control drugs, diethylcarbamazine and doxycycline. Real time PCR based on the Wolbachia ftsZ gene revealed a significant reduction in Wolbachia copy number upon treatment. Anti-Wolbachia and antifilarial properties of CAPE require further investigation as an alternative strategy to treat LF.

Oral ketamine induced pathological changes of the urinary tract in a rat model

INTRODUCTION

In recent years, prolonged ketamine abuse has been reported to cause urinary tract damage. However, there is little information on the pathological effects of ketamine from oral administration. We aimed to study the effects of oral ketamine on the urinary tract and the reversibility of these changes after cessation of ketamine intake.

METHODS

Rats were fed with illicit (a concoction of street ketamine) ketamine in doses of 100 (N=12), or 300 mg/kg (N=12) for four weeks. Half of the rats were sacrificed after the 4-week feeding for necropsy. The remaining rats were taken off ketamine for 8 weeks to allow for any potential recovery of pathological changes before being sacrificed for necropsy. Histopathological examination was performed on the kidney and urinary bladder.

RESULTS

Submucosal bladder inflammation was seen in 67% of the rats fed with 300 mg/kg illicit ketamine. No bladder inflammation was observed in the control and 100 mg/kg illicit ketamine groups. Renal changes, such as interstitial nephritis and papillary necrosis, were observed in rats given illicit ketamine. After ketamine cessation, no inflammation was observed in the bladder of all rats. However, renal inflammation remained in 60% of the rats given illicit ketamine. No dose-effect relationship was established between oral ketamine and changes in the kidneys.

CONCLUSION

Oral ketamine caused pathological changes in the urinary tract, similar to that described in exposure to parenteral ketamine. The changes in the urinary bladder were reversible after short-term exposure.

Circulating NK cells and their subsets in Behçet's disease

Behçet's disease (BD) is an autoinflammatory, chronic relapsing/remitting disease of unknown aetiology with both innate and acquired immune cells implicated in disease pathogenesis. Peripheral blood natural killer (NK) cells and their CD56^Dim /CD56^Bright subsets were surface phenotyped using CD27 and CD16 surface markers in 60 BD patients compared to 60 healthy controls (HCs). Functional potential was assessed by production of interferon (IFN)-γ, granzyme B, perforin and the expression of degranulation marker CD107a. The effects of disease activity (BD^Active versus BD^Quiet ) and BD medication on NK cells were also investigated. Peripheral blood NK cells (P < 0·0001) and their constituent CD56^Dim (P < 0·0001) and CD56^Bright (P = 0·0015) subsets were depleted significantly in BD patients compared to HCs, and especially in those with active disease (BD^Active ) (P < 0·0001). BD patients taking azathioprine also had significantly depleted NK cells compared to HCs (P < 0·0001). A stepwise multivariate linear regression model confirmed BD activity and azathioprine therapy as significant independent predictor variables of peripheral blood NK percentage (P < 0·001). In general, CD56^Dim cells produced more perforin (P < 0·0001) and granzyme B (P < 0·01) expressed higher CD16 levels (P < 0·0001) compared to CD56^Bright cells, confirming their increased cytotoxic potential with overall higher NK cell CD107a expression in BD compared to HCs (P < 0·01). Interestingly, IFN-γ production and CD27 expression were not significantly different between CD56^Dim /CD56^Bright subsets. In conclusion, both BD activity and azathioprine therapy have significant independent depletive effects on the peripheral blood NK cell compartment.

Antifilarial and Antibiotic Activities of Methanolic Extracts of Melaleuca cajuputi Flowers

We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis.

Late lead Perforation Following Permanent Pace Maker Implantation--A Case report

Ventricular lead perforation is an infrequent but it's a critical complication of pacemaker implantation. Perforation was usually associated with the use of small-caliber active fixation leads, and can occur beyond the first few days (sub acute) or even more than a month after implantation (late). We report the case of right ventricular perforation by a ventricular fixation lead in 61 years old man detected more than two months after implantation. Radiology and echocardiography can confirm the perforation by revealing progression of the lead beyond the cardiac silhouette or indirectly visualizing the presence of pericardial effusion. However, its pathophysiology and optimal management are currently unclear.

Temporal analysis of dissolution by-products and genotoxic potential of spherical zinc-silicate bioglass: "imageable beads" for transarterial embolization

Embolization of vascular tumors is an important tool in minimally invasive surgical intervention. Radiopaque, non-degradable, and non-deformable spherical zinc-silicate glass particles were produced in a range of 45-500 μm. Three size ranges (45-150, 150-300, and 300-500 μm) were used in the current study. The glass microspheres were eluted in polar (saline solution) and non-polar (dimethyl sulfoxide) medium, and ion release profiles were recorded using inductively coupled plasma atomic emission spectroscopy. Approximately 80% of Gaussian distribution was achieved by simple sieving. The ions released from the microspheres were dependent upon surface area to volume ratio as well as the nature of elution media. Greater ions were released from smaller particles (45-150 μm) having largest surface area in polar medium. For the genotoxicity bacterial mutation Ames assay, the concentrations of all the ions were well below their therapeutic concentration reported in the literature. No mutagenic effect was observed in the bacterial mutation Ames test. Hence, it can be concluded that the glass microspheres produced herein are non-mutagenic further supporting the materials potential as a suitable embolic agent.

Efficacy of Low Dose Low Molecular Weight Heparin in the Treatment of Cutaneous Lichen Planus

Introduction: Lichen planus is a common pruritic, inflammatory disease of the skin, mucous membranes, nail and hair follicles. Low dose low molecular weight heparin is administered in the treatment of cutaneous lichen planus. Objective: The objective is to evaluate the efficacy of low dose low molecular weight heparin in the treatment of cutaneous lichen planus. Materials and Methods: An interventional study was carried out in the department of Dermatology and Venereology, Combined Military Hospital (CMH), Dhaka. Total thirty seven patients of cutaneous lichen planus were selected by purposive type non-probability sampling technique. Data were collected by face to face interview and clinical examination. Results: It was observed that before treatment, the score of cutaneous lichen planus lesion was 6.83 ± 1.30 and after treatment was 3.83 ± 1.18 and ‘t’ test was found statistically significant (P<0.05). Improvement was shown in 26 (70.27%) cases. Out of these, response was good in 23 (88.46%), fair in 2 (7.69%) and poor in 1 (3.85%) cases. Conclusion: The study revealed that low dose low molecular weight heparin has remarkable efficacy profile as treatment option for cutaneous lichen planus. DOI: http://dx.doi.org/10.3329/jafmc.v9i1.18717 Journal of Armed Forces Medical College Bangladesh Vol.9(1) 2013: 2-7

Parasitic worms stimulate host NADPH oxidases to produce reactive oxygen species that limit plant cell death and promote infection

Plants and animals produce reactive oxygen species (ROS) in response to infection. In plants, ROS not only activate defense responses and promote cell death to limit the spread of pathogens but also restrict the amount of cell death in response to pathogen recognition. Plants also use hormones, such as salicylic acid, to mediate immune responses to infection. However, there are long-lasting biotrophic plant-pathogen interactions, such as the interaction between parasitic nematodes and plant roots during which defense responses are suppressed and root cells are reorganized to specific nurse cell systems. In plants, ROS are primarily generated by plasma membrane-localized NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidases, and loss of NADPH oxidase activity compromises immune responses and cell death. We found that infection of Arabidopsis thaliana by the parasitic nematode Heterodera schachtii activated the NADPH oxidases RbohD and RbohF to produce ROS, which was necessary to restrict infected plant cell death and promote nurse cell formation. RbohD- and RbohF-deficient plants exhibited larger regions of cell death in response to nematode infection, and nurse cell formation was greatly reduced. Genetic disruption of SID2, which is required for salicylic acid accumulation and immune activation in nematode-infected plants, led to the increased size of nematodes in RbohD- and RbohF-deficient plants, but did not decrease plant cell death. Thus, by stimulating NADPH oxidase-generated ROS, parasitic nematodes fine-tune the pattern of plant cell death during the destructive root invasion and may antagonize salicylic acid-induced defense responses during biotrophic life stages.

Cytocompatibility assessment of chemical surface treatments for phosphate glass to improve adhesion between glass and polyester

Fully resorbable phosphate glass fiber reinforced polymer composites have shown real potential for replacing some of the existing metallic bone fracture fixation devices. However, some of these composites have not provided suitable mechanical strength profiles over the required healing period for bone. Typically, it has been seen that these composites can lose up to 50% or more of their strength within the first week of degradation. Functionalizing the glass surface to promote polymer adhesion or to introduce hydrophobicity at the glass surface could potentially introduce control over the mechanical properties of the composite and their retention. In this study eight chemical agents namely, Glycerol 2-phosphate disodium salt; 3-phosphonopropionic acid; 3-aminopropyltriethoxy silane; etidronic acid; hexamethylene diisocyanate; sorbitol/sodium ended PLA oligomers and amino phosphonic acid, were selected to functionalise the bulk phosphate glass surface. Selected chemical agents had one functional group (-OH or O C N) to react with the glass and another functionality (either -OH, NH2, or Na) to react with the polymer matrix and/or produce hydrophobicity at the fiber surface. Bulk phosphate glass surface-treated with the above agents were assessed for the cytotoxicity of degradation products cell-material interaction in short- and long-term direct cytocompatibility studies. Results obtained from these cytocompatibility studies (using human osteosarcoma (MG63) and primary human osteoblast cell lines) revealed no cytotoxicity from the degradation products and a response comparable to controls in terms of cell functions (attachment, viability, metabolic activity, proliferation, and differentiation) and morphology.

Material characterisation and cytocompatibility assessment of quinternary phosphate glasses

Six phosphate glass formulations (in the system P(2)O(5)-CaO-MgO-Na(2)O-Fe(2)O(3)) were produced with fixed magnesium and calcium content at 24 and 16 mol%, respectively. P(2)O(5) and Fe(2)O(3) were varied between 40-50 and 0-4 mol% respectively, with the balance being Na(2)O. EDX analyses confirmed the final composition of the glasses investigated to within a 1-2 % error margin. Thermal analyses showed a linear increase in T(g) with increasing Fe(2)O(3) and P(2)O(5) contents, with Fe(2)O(3) showing a greater effect than P(2)O(5). This was proposed to be due to the formation of Fe-O-P bonds and an increase in the cross-link density of the glass network enhancing the durability of the glass. The glasses that were investigated revealed a decrease in degradation rate with increasing Fe(2)O(3) and P(2)O(5) contents and again the effect of Fe(2)O(3) was greater. All the above characteristics correlated well with structural changes measured by IR and XPS analyses. Cytocompatibility studies showed good cellular (MG63) response to the glasses up to 168 h in terms of cell viability, proliferation and differentiation. Statistical analysis revealed that all the formulations with the exception of P50Fe4 gave a comparable response to the control (TCP), which suggested that after a threshold level of glass durability is achieved the degradation rate has no or minimal effect on biocompatibility. However, it was seen that the glass chemistry can also affect cellular response, since increasing the P(2)O(5) content promoted phenotypic expression that was not related to degradation rate but to the degradation products. This was supported using an elution assay.

Evaluation of PCR with culture for the diagnosis of pulmonary tuberculosis

Tuberculosis (TB) is a major public health problem in most developing countries. The present study was carried out among 100 clinically suspected pulmonary TB patients. One hundred sputum specimens were collected one from each of the suspects attending DOT'S corner of Mymensingh Medical College Hospital, Mymensingh, Bangladesh. The aim of the study was to evaluate the sensitivity and specificity of a polymerase chain reaction (PCR) based method detecting IS6110 sequence present in all Mycobacterium tuberculosis strains using sputum samples in comparison to culture on Lowenstein-Jensen mediums. The PCR was done using primers mtb1 & mtb2 which commonly target an insertion sequence of the organism (IS6110). Out of 100 samples, 18 (18%) showed PCR positive, whereas culture in Lowenstein-Jensen media were positive in 19(19%). In PCR 1 was false negative but none was false positive. In present study, sensitivity and specificity of PCR found 94.74% and 100% respectively. Analyzing the findings of the present study, it can be concluded that the PCR technique is a rapid and alternative method of culture on Lowenstein-Jensen medium for the diagnosis of pulmonary tuberculosis. In the present study, only presence or absence of M. tuberculosis was determined.

Serum hyaluronic acid as a predictor of fibrosis in chronic hepatitis B and C virus infection

Chronic hepatitis B and C virus infection can lead to cirrhosis and hepatocellular carcinoma. Several studies investigated the diagnostic and prognostic value of some biochemical markers to detect the hepatic fibrosis and found a correlation between serum markers and hepatic fibrosis. Among them serum hyaluronic acid (HA) has been identified as a potential marker of fibrosis or cirrhosis in different studies. A prospective study in 60 subjects was conducted to evaluate the association between serum HA and hepatic fibrosis. Thirty consecutive patients with chronic HBV or HCV infection undergoing liver biopsy were studied. Sera were obtained for HA using enzyme linked protein binding assay. Patients with hepatic fibrosis had higher serum HA concentration compared with healthy subjects (236.65 ± 227.07 vs. 23.32 ± 14.22 respectively, p<0.001). Correlation was found between high serum HA concentration and increasing degree of hepatic fibrosis (R-0.322 and p<0.041). This study had shown a good correlation between serum HA and different stages of hepatic fibrosis. So serum HA may be used as a useful marker of hepatic fibrosis.

Detection of biofilm formation among the isolates of staphylococcus epidermidis by modified microtiter- plate test

The present study was done to detect biofilm formation among the strains of Staphylococcus epidermidis isolated from different clinical specimens and healthy controls in the department of Microbiology, Mymensingh Medical College between July 2007 to June 2008. A total of 62 Staphylococcus epidermidis isolates were identified by standard microbiological technique. Among them 32 S. epidermidis were isolated from cases and 30 were from healthy controls. Antimicrobial susceptibility of the isolates was carried out by disk diffusion method as per recommendation of Clinical and Laboratory Standard Institute 2007. Biofilm production was detected by Modified microtiter-plate test. Out of 32 clinical isolates of S. epidermidis, 13 strains found to produce biofilm. On the other hand out of 30 S. epidermidis from healthy controls, only 5 strains produced biofilm. So detection rate of biofilm production of S. epidermidis by Modified microtiter plate test in clinical isolates was significantly higher than that of control group.

Prevalence and antimicrobial resistance of methicillin resistant Staphylococcus epidermidis isolated at Mymensingh Medical College Hospital

The study was done to determine the drug resistance pattern of Methicillin resistant Staphylococcus epidermidis (MRSE) isolated from different clinical specimens at Mymensingh Medical College Hospital, Mymensingh during the period from July 2007 to June 2008. A total of 32 Staphylococcus epidermidis were isolated from 200 different clinical specimens by standard microbiological techniques. Antimicrobial susceptibility of all the isolates was carried out by disk diffusion method as per recommendation of Clinical and Laboratory Standard Institute 2007. Out of 32 Staphylococcus epidermidis 18(56.25%) were detected as Methicillin resistant Staphylococcus epidermidis (MRSE) by disk diffusion method. In this study, Methicillin resistant Staphylococcus epidermidis showed multidrug resistance. Resistant to penicillin, amoxycillin, oxacillin and cloxacillin was 100% followed by gentamycin (56%), erythromycin (50%), doxycycline (44%), cephradine (44%), ciprofloxacin (39%), fucidic acid (33%), cefuroxime (33%) and ceftriaxone (28%). All isolates of MRSE were susceptible to rifampicin and vancomycin.

Hepatitis B immunization of healthy elderly adults: relationship between naïve CD4+ T cells and primary immune response and evaluation of GM-CSF as an adjuvant

The efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF) to enhance the primary immune response to hepatitis B vaccine was studied in healthy elderly with young volunteers included as controls in this double-blind, placebo-controlled trial of GM-CSF as an immune adjuvant. Naïve T-helper cells (CD4+CD45RA+) were determined at baseline. Forty-five healthy elderly (average age, 74 years) and 37 healthy young controls (average age, 28 years) were randomized. Hepatitis B vaccine was administered at 0, 1, and 6 months. GM-CSF as a single injection of either 80 microg or 250 microg with the first and second doses of hepatitis B vaccine. In this trial GM-CSF did not enhance antibody responses. However, the antibody responses were dramatically different between these two groups: 35/35 young developed a protective titer versus 19/45 elderly (P < 0.0001). In addition, the mean logarithm of anti-hepatitis B antibody level in the 35 young who completed the study was 3.17 (log mIU/ml) but only 2.21 in the 19 elderly responders (P < 0.0001). Naïve T-helper cells differed significantly between the two groups: the mean percentage of CD4+CD45RA+ T cells was 47.9% versus 35.0% (P < 0.0001) in the young and elderly volunteers respectively. Naïve T cells also differed significantly between elderly who did or did not respond to HBV (39.9% vs. 31.7%, P = 0.039). Using linear regression, age, and percent naive, CD4 T cells were determined to significantly influence the anti-hepatitis B antibody response, but sex and dose of GM-CSF did not. For a two-parameter model: logarithm of antibody titer = (-0.038 x age in years) + (0.031 x % naïve CD4T cells) + 2.68; adjusted r2 = 0.605 and P < 0.0001. However, age had a larger effect than naive CD4 T cells, i.e., in comparing young and elderly groups the log antibody titer decreased by 1.73 due to the increase in age but only 0.40 due to the decrease in naive CD4 T cells. Thus, there was a large effect of age that could not be explained by the quantitative change in the naïve T-helper cells.

Effects of interleukin-15 on in vitro human T cell proliferation and activation

Interleukin-15 (IL-15) has been reported to have many activities on T cell populations, including a potential role in improving antigen-specific proliferation in HIV-1 disease. We tested this response in healthy adults by studying the response of T cell populations after stimulation with medium, tetanus, cytomegalovirus (CMV) antigens in cultures from 21 volunteers. IL-15 caused a dose-dependent increase in medium and antigen-induced proliferation. The expansion was due to CD8>natural killer (NK)>CD4 lymphocytes and memory > naive cells. The IL-15-stimulated CD8 cells had increased levels of the activation markers CD69 and DR. The published CMV-induced expression of CD57 on CD8+ cells was increased in CMV seronegative and seropositive subjects by IL-15. IL-15 appears to be a stimulator of T cell populations in healthy adults and may be useful in settings to enhance nonspecific NK activity or antigen-specific CD8 activity.

Granulocyte macrophage colony-stimulating factor as an adjuvant for hepatitis B vaccination of healthy adults

Granulocyte macrophage colony-stimulating factor (GM-CSF) has shown promise as an adjuvant to improve the kinetics and magnitude of the immune response after vaccination. It was hypothesized that GM-CSF given intramuscularly (IM) with hepatitis B vaccine would result in increased seroconversion rates and antibody titers. In total, 108 healthy volunteers (18-45 years old) received recombinant hepatitis B vaccine IM at 0, 1, and 6 months and were randomized to receive either concurrent GM-CSF (80 or 250 microgram) or placebo IM with the first two vaccinations. The percentages of subjects achieving a protective level of antibody at day 56 were 58.3%, 58.8%, and 58.3% in the placebo and 80- and 250-microgram GM-CSF arms, respectively. The geometric mean titers of antibody measured on days 28, 56, and 189 were not statistically different between arms. GM-CSF given immediately before recombinant hepatitis B vaccination was safe and well tolerated but did not appear to provide significant adjuvant activity at this dose.

Primary isolate neutralization by HIV type 1-infected patient sera in the era of highly active antiretroviral therapy

Sera from highly selected HIV-1-positive patients are known to have the ability to neutralize a diverse array of primary isolates of HIV-1. The human osteosarcoma cell line that expresses CD4 and chemokine receptors (GHOST cells) was adapted to study HIV-1 neutralization in 37 HIV-1-infected individuals who were selected because of slow disease progression or nonprogression. Many of these individuals were receiving combination drug therapy. Molecularly cloned HIV-1 JR-FL and NL4-3 viruses were used as prototypes to define assay conditions. Sera were then tested at a 1:40 dilution against six additional primary isolates, three of which utilized CCR5 and three of which used both CCR5 and CXCR4. The assay was highly reproducible and independent of viral input titer, with a readout at 48 hr equivalent to that at later time points. As previously reported, neutralization sensitivity was entirely independent of coreceptor usage. Only a few sera from slow progressors were able to neutralize a broad array of primary isolates at a 1:40 dilution, and the best clinical predictor of broadly neutralizing antibody for primary isolates was the present use of antiretroviral agents. In further studies it was found that purified antibody accounted for the majority of the measured neutralization. However, experiments with exogenous addition of antiviral agents showed that the use of nucleosides also greatly contributed to the measured neutralization in some patients. Measurement of neutralization of HIV-1 primary isolates by sera from patients receiving antiretroviral therapy must be carried out with some caution.

Development of a fluorescent light technique for evaluating microdamage in bone subjected to fatigue loading

A new method using fluorescent light microscopy has been developed to visualize and evaluate bone microdamage. We report the findings of two different experiments with a common aim of comparing the fluorescent light technique to the brightfield method for quantifying microdamage in bone. In Experiment 1, 36 canine femurs were tested in four-point cyclic bending until they had lost between 5 and 43% of their stiffness. The loaded portion of the bone was stained en bloc with basic fuchsin for the presence of damage. Standard point counting techniques were used to calculate fractional damaged area (Dm.Ar = Cr.Ar/B.Ar, mm2/mm2) under brightfield and fluorescent microscopy. In Experiment 2, bone microdamage adjacent to endosseous implants, subjected to fatigue loading (150,000 cycles, 2 Hz and 37 degrees C) ex vivo was examined. The bone around the implant was either allowed to heal (adapted specimen) for 12 weeks after placement in dog mid-femoral diaphyses prior to testing or was loaded immediately to simulate non-healed bone surrounding endosseous implants (non-adapted). Crack numerical density (Cr.Dn = Cr.N/B.Ar, #/mm2), crack surface density (Cr.S.Dn = Tt.Cr.Le/B.Ar, mm/mm2) and fractional damaged area were calculated separately by both techniques in the adapted and non-adapted specimens. In both Experiments 1 and 2, significantly more microdamage was detected by the fluorescent technique than by the brightfield method. Also, there was a trend towards higher intraobserver repeatability when using the fluorescent method. These results suggest that the brightfield technique underestimates microdamage accumulation and that the fluorescent technique better represents the actual amounts of microdamage present. The results demonstrate that the fluorescent method provides an accurate and precise approach for bone microdamage evaluation, and that it improves the prediction of stiffness loss from damage accumulation.

Application of artificial neural network for micro-crack and damage evaluation of bone

This paper presents the reasoning and adaptive learning method of artificial neural network (ANN) for micro-crack assessment and damage accumulation due to stiffness loss of dog bone. The importance of using the alternative approach of ANN is that it avoids the complexity of modeling problems, overrides the consideration of simplified assumptions and can be developed directly from experimental data using adaptive learning mechanisms. The proposed artificial neural network model provides a relationship between microdamage accumulation, stiffness loss and number of fatigue cycles (Nf) to failure from an experimental study where stiffness loss and crack area (Cr.Ar., mm2/mm2) are evaluated. This preliminary study using ANN for microdamage evaluation shows that ANN accurately predicts the amount of damage accumulation from stiffness loss.

Does microdamage accumulation affect the mechanical properties of bone?

It has never been demonstrated that microcrack accumulation in bone leads to impaired mechanical properties. We hypothesized that microdamage accumulation is positively and linearly correlated with a reduction in bone's elastic modulus. We also tested the hypothesis that damage accumulates more rapidly in tensile cortices, but crack growth is greater in compressive cortices. Canine femurs (n = 26) were tested in four-point cyclic bending under load control until they had lost between 5 and 43% of their stiffness. Ten femurs were used as nonloaded controls. The loaded portion of the bone was stained en bloc with basic fuchsin to detect the presence of microdamage. The number of stained microcracks, their lengths and the area of damaged bone were measured under the microscope. Crack numerical density, surface density, mean crack length, and the percentage of damaged area were calculated. Significant microdamage accumulation was not detected until the bone had lost 15% of its elastic modulus. The relationship between crack density and stiffness loss was approximately quadratic, but the relationship between damaged area and stiffness loss was linear. There were significantly more microcracks in tensile cortices, but on average cracks were significantly longer in compressive cortices. We conclude that microcrack accumulation impairs the mechanical properties of bone by reducing its elastic modulus. We also conclude that damage accumulates more rapidly in tensile cortices, but crack growth is greater in compressive cortices.

Renal Transplantation in the Gulf Co-operation Council Countries

The Gulf Co-operation Council (GCC) which has six member-countries was established in 1981 to promote mutual co-operation on various aspects including health care. Efforts are ongoing to have active co-ordination among the member-countries in the field of organ transplantation. Islamic scholars in these countries have approved organ donation from living related and cadaveric donors after obtaining consent from the families concerned. This has paved the way for the implementation of successful renal transplantation programs in many of the GCC countries. The results of the operations performed locally in these countries are encouraging and similar. However, the demand for organs is still high and only 30% of the need is being met at present. Commercial organ donation is strictly prohibited in all these countries. In Saudi Arabia, the Saudi Center for Organ Transplantation (SCOT), erstwhile National Kidney Foundation, was established in 1985. The main objective was to coordinate organ transplantation program in the Kingdom and in the last ten years, the center has gathered remarkable experience in this field. Other GCC countries need to establish cadaveric renal transplantation programs in their countries on similar lines as SCOT.