Serum Uric Acid and Serum Lipid Levels in Patients with Acute Ischemic Stroke Admitted in Mymensingh Medical College Hospital

Stroke is the second-leading cause of death and also a leading cause of combined death and disability. In Bangladesh, stroke prevalence is 11.39 per 1000 population, but highest prevalence of stroke is 14.71 per 1000 population in the Mymensingh division. Hyperuricemia has been reported as an independent risk factor for stroke in different studies and a significant association between serum uric acid and dyslipidemia has also been stated. On the contrary, some studies suggest that uric acid has a neuroprotective role. This cross-sectional study was completed in the Medicine Department of Mymensingh Medical College Hospital, Mymensingh, Bangladesh from March 2021 to January 2023. In this cross-sectional study, 352 adult acute ischemic stroke patients were included from the Medicine Department of Mymensingh Medical College Hospital. Serum uric acid and fasting serum lipid levels were measured within 48 hours of admission. The mean age ±SD of the respondents was 61.9±12.8 years. Hyperuricemia was found among 18.2% of respondents, whose mean ±SD serum uric acid was 5.7±1.9 mg/dl. Dyslipidemia was present in 88.4% of patients. The mean ±SD of the National Institutes of Health Stroke Scale (NIHSS) score was 12.0±5.9. Most of the patients (65.6%) were suffering from moderate stroke, followed by moderate to severe stroke (15.1%), severe stroke (10.8%) and minor stroke (8.5%). After multiple linear regressions, the independent variables age, gender, serum uric acid and total cholesterol were found to be significant predictors of the NIHSS score of the respondents. In conclusion, the majority of acute ischemic stroke patients have an association with dyslipidemia, but only around one-fifth of patients have hyperuricemia. There is a significant association of high serum uric acid and high serum total cholesterol with stroke severity (NIHSS score). But low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and, triglycerides have no association with stroke severity.

Feasibility of using a transmission ion chamber for QA tests of medical linear accelerators

PURPOSE

To study the feasibility of using the Integral Quality Monitoring (IQM) system for routine quality assurance (QA) of photon beams.

METHODS

The IQM system is a commercially available dose delivery verification tool, which consists of a spatially sensitive large area transmission ion chamber, mounted on the Linac collimator, and a calculation algorithm to predict the signals in response to radiation beams. By comparing the measured and predicted signals the system verifies the accuracy of beam delivery. The ion chamber unit is a battery powered system including a dual-electrometer, temperature and pressure sensors, and inclinometers. The feasibility of using the IQM system for routine QA tests was investigated by measuring constancy values of beam parameters, with specially designed tests fields, and comparing them with those determined by a conventional system.

RESULTS

The sensitivity of the beam output constancy measurements by the IQM system was found to agree with those measured by a Farmer type ion chamber placed in water phantoms to within 0.1% for typical daily output variation of ± 0.5% and ± 1%. The beam symmetry was measured with a 4 cm × 4 cm aperture at multiple off-axis distances and was found to have a highly linear relationship with those measured in a water phantom scan for intentionally introduced asymmetry between -3% and +3%. The beam flatness was measured with a two-field ratio method and was found to be linearly correlated with those measured by water phantom scan. The dosimetric equivalent of a picket fence test performed by the IQM system can serve as a constancy check of the multileaf collimator (MLC) bank positioning test.

CONCLUSIONS

The IQM system has been investigated for constancy measurements of various beam parameters for photon beams. The results suggest that the system can be used for most of the routine QA tests effectively and efficiently.

Ocular Involvement in Transfusion Dependent Thalassemia Children

Thalassemia is one of the most common haemoglobinopathies in the world. Transfusion dependent thalassemia patients need regular blood transfusion. Repeated blood transfusions lead to iron overloads which can affect various organs in the body including eyes. The present study aims to evaluate the ocular involvements in transfusion dependent thalassemia children and their relationship with duration of the disease and serum ferritin level. This cross-sectional observational study included 46 multi-transfused thalassemia children aged 3-18 years. Detailed ophthalmological examination including visual acuity, slit lamp bio microscopy, direct and indirect ophthalmoscopy was done. Statistical analysis was done using SPSS version (IBM) 23.0. Student's t-test and chi-square (χ²) test was done and p value of <0.05 was considered significant. Out of 46 thalassemia children male were 25(54.3%) and female were 21(45.7%). Mean age of the children was 8.94±5.04 years, mean duration of disease was 7.02±3.5 years and mean serum ferritin level 1543.68±914.43ng/dl. Ocular involvements were detected in 19(41.3%) children. Among them 8(17.39%) children had more than one ocular involvements. The ocular manifestations were decreased visual acuity in 17(36.95%), corneal dryness in 7(15.21%), lens opacity in 6(13.04%), optic disc atrophy in 7(15.21%), peripheral retinal pigmentation in 5(10.86%) and retinal vessels tortuosity in 3(6.52%) children. Higher serum ferritin level and increased duration of the disease were significantly (p<0.001) related with ocular involvement. Various ocular involvements were found in transfusion dependent thalassemia children. Therefore, transfusion dependent thalassemia children should be screened periodically for early detection and proper management of ocular changes.

Role of Intra-arterial Nitroglycerin (Post Procedural, Prehemostasis) to Reduce Radial Artery Occlusion after Transradial Catheterisation: A Doppler-guided Study

The study was intended to evaluate efficacy of Intra-arterial nitroglycerin through the sheath at the end of a transradial procedure to preserve the patency of the radial artery. This prospective observational study was done in the Department of Cardiology, National Institute of Cardiovascular Diseases (NICVD), Dhaka, Bangladesh from May 2017 to April 2018, by including a total 200 patients undergoing coronary procedures (CAG and / or PCI) through TRA. RAO was defined as an absence of antegrade flow or monophasic flow or invert flow on Doppler study. In this study 102 patients (Group I) received 200 mcg intra-arterial nitroglycerine, prior to trans-radial sheath removal. Another 98 patients (Group II) did not receive intra-arterial nitroglycerine prior to trans-radial sheath removal. Conventional haemostatic compression methods were applied (average 2 hours) in both groups of patients. Evaluation of radial arterial arterial blood flow by colour Doppler study was done on next day after the procedure in both groups. Results of this study in which RAO was determined by vascular doppler study showed that frequency of radial artery occlusion were 13.5% one day after transradial coronary procedures. We found the incidence was 8.8% vs. 18.4%, (p=0.04) in Group I and Group II respectively. The incidence of RAO was significantly lower in post procedural nitroglycerine group. From multivariate logistic regression analysis diabetes mellitus (p = 0.02), hemostatic compression time for more than 02 hours after sheath removal (p = <0.001) and procedure time (p = 0.02) was predictors of RAO. So, the administration of nitroglycerin at the end of a transradial catheterization reduced the incidence of RAO, as shown by 1 day after the radial procedure by doppler ultrasound.

Management of Neglected Rupture of Tendoachilles with Long Gap by Flexor Hallucis Longus Tendon Transfer

The tendo achilles is one of most important tendon in human body which often injured through direct trauma or indirect stress on a weakened tendon. Longer the duration after injury the injured parts likely to move apart, fibrosis and degeneration leading to difficulty in repair or reconstruction. Usually a phase of 4 weeks or more without specific treatment is regarded as chronic or neglected rupture. Different authors described many management protocols about the tendo achilles rupture but there is no procedure of choice for neglected rupture with long gap. Prospective case series of 21 patients of neglected tendo achilles rupture with long gap treated with flexor hallucis longus tendon (FHLT) transfer was taken for study from January 2019 to December 2020 in Mymensingh Medical College Hospital, Bangladesh. Average age of patients was 39.47 years with range 22-65 years. Fifteen (15) cases of traumatic rupture in this study with average age 32.66 years and pathologic 6 cases with average age 56.5 years were recorded. We grafted FHLT from channel by incising Henry's knot. Krackow et al.'s technique was followed for tendon mobilization and bone fixation. We made procedure simpler and cheaper; instead of using interference screw the sutured tendon pulled through the heel and anchored over rubber tube or button by Cole method. Post-operative complications were less with one patient with superficial infection which eventually recovered 3 cases of mild pain and 2 cases of numbness. Questionnaire for surgical outcome measure are satisfactory in 19 patients (90.47%). Final follow up AOFAS score at 6 month (91.61±5.41) was highly significant (p<0.001) in comparison to preoperative score (38.71±9.78). These are comparable to other study. Above mentioned scores indicate the reliability of the surgical system. But our study is a prospective case series with minimum cases. To establish the best procedure for neglected tendo achilles rupture with long gap we recommend further study with larger group and Randomized Controlled Trial (RCT) study among different procedure.

Risk Factors of UTI in Children with Nephrotic Syndrome

Urinary tract infection (UTI) is a common complication in nephrotic children and leads to most morbidity and mortality in developing countries like Bangladesh. This case control study was conducted in the Department of Pediatrics and Pediatric Nephrology ward of Dhaka Medical College Hospital, Dhaka from July 2016 to June 2018 to identify the risk factors of UTI in children with nephrotic syndrome. Total 90 patient of nephrotic children aged 2-12 years, who were fulfilling the inclusion and exclusion criteria were selected as Group I (case) and Group II (control) according to urine culture report. Group I was UTI positive and Group II was UTI negative. The mean age of Group I was 5.26±3.18 years and Group II was 6.03±2.85 years. There was male predominance in both groups. No significant difference has been found regarding age and sex (p>0.05). No significant difference was also observed regarding economic status and educational level of mother among both groups (p>0.05). Fever, dysuria, abdominal pain, anasarca, vomiting and pallor were found as common presentations in Group I. Children with dysuria and abdominal pain were significantly higher in Group I than Group II (p value <0.001). UTI was found more in relapsed cases than initial attack. E. coli was the most common etiologic agent (37.8%). Mean Hb (gm/dl), serum total protein, serum albumin and serum IgG level were found significantly lower and spot urine protein creatinine ratio was significantly higher in Group I, which implies that those biochemical factors were associated with development of UTI in nephrotic children. Younger age group (<6 years), Constipation and uncircumcised male were found as risk factors and has association with UTI in nephrotic children.

Clinical Outcome on Comminuted Femoral Shaft Fractures in Adults Treated by Minimally Invasive Plate Osteosynthesis (MIPO) with Locking Plate

Intramedullary nailing is a pillar in the treatment of femoral shaft fractures. But it is not possible in all cases especially in comminuted fractures. This study has been designed to explain the importance of Minimally Invasive Plate Osteosynthesis (MIPO) with the locking plate in the treatment of comminuted Femoral Shaft Fracture. Twenty (20) such patients were treated by MIPO and analysis has been done in this study to get fruitful result and to find out the effectiveness of this procedure who were admitted at Mymensingh Medical College Hospital, Mymensingh, a tertiary level hospital of Bangladesh from February 2018 to January 2019. Mean age of the patients were 49.20±14.41 years. Based on AO classification, there were 4, 8 and 8 patients belong to type A, B and C respectively. The union period for all the patients was in between 12 to 14 weeks. The mean union period was 12.90±1.997 weeks. Mean follow up period was 19.70±2.77 weeks. Mean full weight bearing period was 16.50±1.10 weeks. In Thoresen scoring system excellent result was 9(45%), good result was 10(20%) and fair result was 01(5%). Mal-alignment happened in two cases. However, delayed union and broken screws were found in two cases each of which was treated accordingly. Comminuted Femoral shaft fracture with MIPO procedure is more effective treatment than intramedullary nailing. Furthermore, mal-alignment is the basic complexity that must be taken away intraoperatively.

Core Decompression with Non Vascularized Fibular Graft as Modern Surgical Treatment of Early Hip Avascular Necrosis

Cellular death of bone due to impairment of the blood supply leading to collapse resulting in pain, and loss of joint function is known as avascular necrosis (AVN). The head of femur is the most common bone affected by avascular necrosis followed by talus and scaphoid. We evaluate the results of core decompression with non-vascularized fibular graft in avascular necrosis of femoral head. This quasi experimental study was done at Mymensingh Medical College Hospital, Dhaka Medical College Hospital and some other private hospitals of Bangladesh. The study includes patients who underwent core decompression and non-vascularized fibular grafting in avascular necrosis of femoral head from January 2017 to December 2018. In this study we evaluated total 20 patients and majority of the patients belongs to the group of 20-30 years. Out of 20 patients, 8 of them were unilaterally involved rest 12 had bilateral involvement. Out of 24 hips of bilateral involvement 4 were grade III and IV (Ficat and Arlet classification) therefore not included in the study. So, we study 28 hips only. The average success rate was 90% after core decompression and non-vascularized fibular bone grafting. Harris hip score of 60 on presentation had poorer outcome. Patients with less than 80 degrees of flexion had poorer outcome.

Study on Precipitating Factor of Chronic Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a neuro-psychiatric manifestation of chronic liver disease causing significant morbidity and mortality worldwide. Though the exact mechanism is unknown but it is well accepted that various precipitating factors are involved in hepatic encephalopathy. Aim of the study was explore the precipitating factors of chronic hepatic encephalopathy. This cross sectional descriptive study was conducted in the Department of Medicine and Department of Hepatology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh during the period from April 2016 to October 2016. One hundred patients with hepatic encephalopathy fulfilling the inclusion and exclusion criteria were enrolled. Inclusion criteria were designed for all diagnosed cases of hepatic encephalopathy associated with cirrhosis of liver aged 18 years or above irrespective of sex. Patients with acute fulminant hepatitis and non-cirrhotic hepatic encephalopathy were excluded. The result of the study was mean age of hepatic encephalopathy was 52.81±8.15 years and 94.0% patients were above 40 years. Male (66.0%) were predominant over female (34.0%). HBsAg and Anti HCV were positive in 49.0% and 11.0% patients respectively. Stage of hepatic encephalopathy was stage-I in 8.0%, stage-II in 37.0%, stage-III in 39.0% and stage-IV in 16.0% patients. Changes of biochemical parameters were low haemoglobin level (70.0%), raised total count of leukocyte (25.0%), low platelet count (68.0%), low serum albumin (98.0%) raised prothrombin time (60.0%), low serum sodium (34.0%) and low serum potassium (63.0%). The recoded precipitating factors were gastrointestinal bleeding (14.0%), constipation (37.0%), hyponatremia (34.0%), hypokalemia (28.0%) infections (20.0%), use of diruretics (8.0%), use of sedatives (4.0%) and excess intake of protein (6.0%). While precipitating factor was absent in 11.0% of cases. In conclusion there are different factors which play a key role in precipitating hepatic encephalopathy but electrolytes imbalance, constipation, infections, Upper GI bleed, diuretics are the most common precipitating factors.

Quality of Life among Patients with Bipolar Disorder

Bipolar Disorder is a major psychiatric disorder. It has a chronic course of remitting and relapsing episodes of mania and depression and tends to deteriorate mental and cognitive functions of patients. This disorder affects deeply the function and feelings of subjects and impacts negatively on quality of life. We found out the quality of life in patients with Bipolar Disorder with that of general population and order of impairment among domain of physical health, psychological health, social relationship and environment domain. This was a descriptive, cross-sectional, comparative and analytical study. The study was conducted in the department of Psychiatry, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2015 to October 2016. Eighty (80) patients with Bipolar Disorder who fulfilled inclusion criteria were selected as sample from department of psychiatry in BSMMU and National Institute of Mental Health, Dhaka. Clinical diagnosis of patients was done by consultant psychiatrist with Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I CV). Then Bengali version of WHO Quality of Life Scale brief version (WHOQOL BREF 1998) was applied to evaluate quality of life in different domains including physical health, psychological health, social relationship and environment domain. Semi structural questionnaire were used for collecting sociodemographic information. In this process of study age and sex matched 80 healthy controls from hospital staff and patient's attendants without physical or psychiatric illness were recruited for comparison. Data were analyzed by Statistical Package for Social Science Version 16. The study revealed that mean score of overall quality of life of patients were 3.11 and healthy controls were 3.95, mean score of overall health of patients were 2.94 and healthy control were 3.88, mean score of physical health domain of patients were 3.14 and healthy control were 4.00, mean score of psychological domain of patients were 3.01 and healthy control were 3.87, mean score of social relationship domain of patients were 2.31 and healthy control were 3.72, mean score of environment domain of patients were 2.73 and healthy control were 3.35. Among patients quality of life showed impaired in low socio-economic condition. Result of this study may help to encourage further research.

Childhood Adversities as Risk Factors and Persistence of Suicidal Behavior: A Descriptive Cross-Sectional Study

Suicide is one of the important cause of death worldwide. The precise effect of childhood adversities as risk factors for the onset and persistence of suicidal behaviour are not well understood. A descriptive cross sectional study was carried out in the department of Psychiatry, Cumilla Medical College, Cumilla, Bangladesh. All cases were selected from patients attending at Cumilla Medical College hospital and Private Hospitals in Cumilla City from April 2017 to September 2018. We found out the association between childhood adversities and suicidal behaviour over the life course and delineated the types of suicidal behavior. Total 120 cases were included in the study. Respondents provided socio-demographic and diagnostic information, childhood adversities as well as an account of suicide-related thoughts and behaviours. A participation rate was 77.5% female. Of 120 suicidal behavior participants physical abuse was 2.5%, sexual abuse was 16.67%, parental death was 5%, parental divorce was 2.5%, other parental loss was 4.17%, family violence was 5%, physical illness was 1.67%, financial adversity was 3.33% and composite adversity was 59.16%. Among childhood adversities participants suicidal ideation was 70%, suicidal plans was 15.83%, suicidal attempts was 45%, ideators only proceeded to plans was 22.5%, ideation to attempt was 63.33%, planned attempts was 10.83% and impulsive attempts was 52.5%. Among suicidal behavior participant's psychiatric disorders were 65%. Where neurotic disorders were 17%, psychotic disorders were 13%, personality disorders were 44% and others disorder was 26%. Most of the suicidal behavior patients were female 77.5% and age group of 18-24 years. Childhood sexual abuse emerged as a particularly robust risk factor for suicide attempts in younger participants. Childhood physical and sexual abuse emerged as risk factors for the emergence and persistence of suicidal behaviour, especially in adolescence. Two or more childhood adversities were associated with a three fold higher risk of lifetime suicide attempts. Childhood adversities are main risk factors for the onset and persistence of suicidal behaviour. The risks being are the greatest in childhood, adolescence and early adult. A longitudinal follow-up study is required to give a more reliable in Bangladesh.

Methylene-linked bis-phenylbenzimidazoles - a new scaffold to target telomeric DNA/RNA hybrid duplex

We report a series of novel methylene-linked bis-phenylbenzimidazoles intercalators that stabilize telomeric DNA/RNA hybrid (tDRH) structures by up to 7.2 °C at a 1 μM ligand concentration while having negligible affinity for DNA/DNA duplexes, although with a low affinity for quadruplex DNA. We have used molecular modelling studies to rationalize this selectivity, concluding that the methylene spacer between the terminal benzimidazole and phenylene moieties plays a key role in facilitating the bis-intercalating process. This scaffold may be used to develop chemical tools or new therapeutics to selectively target the telomeric DNA/RNA duplex without affecting normal genomic DNA.

Risk Factors and Immediate Outcome of Very Low Birth Weight Babies (Appropriate For Gestational Age) In Newly Established SCANU, Mymensingh Medical College Hospital

Low birth weight (LBW) is the most important preventable cause in the neonatal period leading to very high neonatal mortality and morbidity in developing countries like Bangladesh. A cross sectional study was conducted in the neonatology ward, Mymensingh Medical College Hospital, Mymensingh from July 2014 to December 2014 to identify the risk factors and immediate hospital outcome of Very Low Birth Weight (VLBW) Appropriate for Gestational Age (AGA) babies in context of present neonatal hospital care standard. Total 100 preterm very low birth weight babies were enrolled and selected by weight, intra uterine growth chart and new ballad score. There is slight preponderance of male babies (64%) over female babies (36%). The overall survival and mortality rate was 50% and 50% respectively in the present study. Mortality is highest (76.47%) in babies whose gestational age 28 weeks and the mortality rate gradually decrease as gestational age increases. Correlation co-efficient (r) between gestational age and number of died is -0.85. It indicates highly opposite relation between the variables, p value (<0.069) which is strong opposite relation. Mortality is highest (66.66%) in babies whose birth weight below1100gm, in comparison to those whose birth weight above 1100gm and correlation co-efficient (CC) r = -0.433 (p<0.466) which is not significant. That means not only birth weight but also other factors are responsible for mortality of very low birth weight baby. Neonatal mortality bears inverse relationship with birth weight and gestational age. This emphasized the need for large scale study which will provide the guideline for appropriate measures to be taken to combat the situation.

Abstract 2914: Biphenylene and bipyridine connected benzofuran compounds as novel regulators of kRAS transcription

Pancreatic cancer is the fourth most deadly cancer with 5 year survival rate of ∼6%. One of the major attributes of pancreatic cancer is kRAS mutations. kRAS is a proto-oncogene with intrinsic GTPase activity, and is responsible for cell proliferation, division, and apoptosis. kRAS mutations are observed in &gt;95% of pancreatic adenocarcinoma and in 30% all human tumors. When mutated it leads to continuous activity and uncontrolled proliferation which results in increased tumorigenicity and poor prognosis. Downregulating kRAS expression has shown to halt proliferation and leads to cellular death in pancreatic cancer models, but to date no small molecule capable of such transcriptional silencing has been described. A novel series of molecules with either biphenylene or bipyridine spacer connecting the terminal benzofuran ring was synthesized using solution phase chemistry. Tertiary amine side chains were incorporated to the C2-position of the benzofuran ring to improve the DNA binding affinity of these compounds. The synthesized compounds were purified using a “catch and release” method employing the sulfonic acid based resins. The eleven novel compounds were screened in parallel for their ability to stabilize G-quadruplex structures in the kRAS promoter, and to downregulate kRAS promoter activity. Two of the compounds increased the thermal profile of non-canonical DNA formations in the promoter region by &gt;5 °C; however, on the whole these compounds did not seem to function as G-quadruplex-stabilizing agents. Eight compounds significantly decreased luciferase expression under the explicit control of the kRAS promoter by up to 75%, by compound BF 4.3, through an as-yet unknown mechanism of action. The compound series was examined for the inhibition of cellular viability in two mutant kRAS pancreatic cancer cell lines - Panc-1 and MIA PaCa-2; in both cell lines the compounds containing the bipyridine spacer had greater cytotoxic effects with IC50's of ∼30 μM, consistently. qPCR is being used to confirm the decrease in promoter activity in native cellular conditions. These agents are intriguing in both their novel scaffold and their unexpected activity decreasing kRAS expression in a mechanism unrelated to higher order DNA structures. Ultimately, down regulation of kRAS transcription will provide a novel therapeutic approach for pancreatic cancer and improve the prognosis of this highly lethal disease.

Citation Format: Harshul Batra, Mohammad K. Islam, David E. Thurston, Khondaker M. Rahman, Tracy A. Brooks. Biphenylene and bipyridine connected benzofuran compounds as novel regulators of kRAS transcription. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2914.

Effects of the main extraction parameters on chemical and microbial characteristics of compost tea

The rising popularity of compost tea as fertilizer or foliar spray against pathogens has encouraged many researchers to evaluate its performance without standardizing its quality, so obtaining inconsistent and controversial results. The fertilizing and pesticide-like effects of compost tea are due to its chemical and microbiological properties. Therefore, this study aimed to identify the best combination of the compost tea extraction parameters for exalting both chemical and microbiological features. A factorial design was adopted to evaluate the effects of compost/water ratio, extraction time, storage duration and storage temperature in different combination on physical, chemical and microbiological characteristics of compost tea, and the results were elaborated through different statistical analyses. Compost tea nutrients and microorganisms were influenced by compost/water ratio and extraction time. In addition, the storage duration affected the microbial populations, whereas the storage temperature influenced only the fungal population of compost tea. Results suggested that the best combination of the studied parameters was: 1:2.5 compost/water ratio, 2days of extraction time and the compost tea should be utilized immediately after the extraction, since the storage reduced the microbial populations.

Potential hazard due to induced radioactivity secondary to radiotherapy: the report of task group 136 of the American Association of Physicists in Medicine

External-beam radiation therapy mostly uses high-energy photons (x-rays) produced by medical accelerators, but many facilities now use proton beams, and a few use fast-neutron beams. High-energy photons offer several advantages over lower-energy photons in terms of better dose distributions for deep-seated tumors, lower skin dose, less sensitivity to tissue heterogeneities, etc. However, for beams operating at or above 10 MV, some of the materials in the accelerator room and the radiotherapy patient become radioactive due primarily to photonuclear reactions and neutron capture, exposing therapy staff and patients to unwanted radiation dose. Some recent advances in radiotherapy technology require treatments using a higher number of monitor units and monitor-unit rates for the same delivered dose, and compared to the conventional treatment techniques and fractionation schemes, the activation dose to personnel can be substantially higher. Radiotherapy treatments with proton and neutron beams all result in activated materials in the treatment room. In this report, the authors review critically the published literature on radiation exposures from induced radioactivity in radiotherapy. They conclude that the additional exposure to the patient due to induced radioactivity is negligible compared to the overall radiation exposure as a part of the treatment. The additional exposure to the staff due to induced activity from photon beams is small at an estimated level of about 1 to 2 mSv y. This is well below the allowed occupational exposure limits. Therefore, the potential hazard to staff from induced radioactivity in the use of high-energy x-rays is considered to be low, and no specific actions are considered necessary or mandatory. However, in the spirit of the "As Low as Reasonably Achievable (ALARA)" program, some reasonable steps are recommended that can be taken to reduce this small exposure to an even lower level. The dose reduction strategies suggested should be followed only if these actions are considered reasonable and practical in the individual clinics. Therapists working with proton beam and neutron beam units handle treatment devices that do become radioactive, and they should wear extremity monitors and make handling apertures and boluses their last task upon entering the room following treatment. Personnel doses from neutron-beam units can approach regulatory limits depending on the number of patients and beams, and strategies to reduce doses should be followed.

A stochastic model for tumor geometry evolution during radiation therapy in cervical cancer

PURPOSE

To develop mathematical models to predict the evolution of tumor geometry in cervical cancer undergoing radiation therapy.

METHODS

The authors develop two mathematical models to estimate tumor geometry change: a Markov model and an isomorphic shrinkage model. The Markov model describes tumor evolution by investigating the change in state (either tumor or nontumor) of voxels on the tumor surface. It assumes that the evolution follows a Markov process. Transition probabilities are obtained using maximum likelihood estimation and depend on the states of neighboring voxels. The isomorphic shrinkage model describes tumor shrinkage or growth in terms of layers of voxels on the tumor surface, instead of modeling individual voxels. The two proposed models were applied to data from 29 cervical cancer patients treated at Princess Margaret Cancer Centre and then compared to a constant volume approach. Model performance was measured using sensitivity and specificity.

RESULTS

The Markov model outperformed both the isomorphic shrinkage and constant volume models in terms of the trade-off between sensitivity (target coverage) and specificity (normal tissue sparing). Generally, the Markov model achieved a few percentage points in improvement in either sensitivity or specificity compared to the other models. The isomorphic shrinkage model was comparable to the Markov approach under certain parameter settings. Convex tumor shapes were easier to predict.

CONCLUSIONS

By modeling tumor geometry change at the voxel level using a probabilistic model, improvements in target coverage and normal tissue sparing are possible. Our Markov model is flexible and has tunable parameters to adjust model performance to meet a range of criteria. Such a model may support the development of an adaptive paradigm for radiation therapy of cervical cancer.

A method for online verification of adapted fields using an independent dose monitor

PURPOSE

Clinical implementation of online adaptive radiotherapy requires generation of modified fields and a method of dosimetric verification in a short time. We present a method of treatment field modification to account for patient setup error, and an online method of verification using an independent monitoring system.

METHODS

The fields are modified by translating each multileaf collimator (MLC) defined aperture in the direction of the patient setup error, and magnifying to account for distance variation to the marked isocentre. A modified version of a previously reported online beam monitoring system, the integral quality monitoring (IQM) system, was investigated for validation of adapted fields. The system consists of a large area ion-chamber with a spatial gradient in electrode separation to provide a spatially sensitive signal for each beam segment, mounted below the MLC, and a calculation algorithm to predict the signal. IMRT plans of ten prostate patients have been modified in response to six randomly chosen setup errors in three orthogonal directions.

RESULTS

A total of approximately 49 beams for the modified fields were verified by the IQM system, of which 97% of measured IQM signal agree with the predicted value to within 2%.

CONCLUSIONS

The modified IQM system was found to be suitable for online verification of adapted treatment fields.

Outcome of single-stage transanal endorectal pull through for short segment Hirschsprung's disease in neonates and infants

Hirschsprung's disease (HD) is developmental disorder of the enteric nervous system. Diagnosis can be confirmed by rectal biopsy. The surgical management of HD includes so many procedures. The purpose of this study was to evaluate the out come of single-stage transanal endorectal pull-through operation for short segment HD in neonates and infants. This prospective study was carried out in the Department of Pediatric Surgery, Dhaka Shishu (Children) Hospital, Dhaka, Bangladesh during the period from January 2004 to December 2009. The study included neonates & infants (age 1 day to 1 year) of both sex, who were clinically suspected and biopsy proven HD with barium enema suggesting rectosigmoid HD. We excluded patients with short segment HD who had associated anomalies, and with hugely dilated proximal colon, operated cases with less than 6 months' follow up. During study period, single-stage transanal endorectal pull through (TEP) operation done in 68 neonates and infants patients (8 excluded) of short segment HD. The mean operative time, postoperative hospital stay, followed up time were 120 minutes, 7.94 days and 12 months respectively. Transeverse colostomy was needed in 4 patients because of anastomotic leakage and they were complicated with anastomotic stenosis, however managed by progressive dilatation. Overall parents' satisfaction was achieved. Single-stage primary transnanl endorectal pull-through for short segment HD is feasible in neonates and infants. It preserves all the advantages of minimally invasive surgery. TEP is a better option in terms of comfort, operative success, postoperative morbidity, cosmetic appearance and parents' satisfaction.

Abstract B204: Targeting key DNA/RNA heteroduplex of telomerase by small-molecule ligands

Small molecules can be designed to target the DNA/RNA hybrid (DRH) duplex that forms during the catalytic cycle of telomerase. Formation of this unique heteroduplex, which is typically between 4-11 base pairs long, is a key step in the mechanism of telomerase extension. Small molecules that bind to this duplex may inhibit telomerase by either stabilizing the structure thereby preventing strand dissociation (a key step in the catalytic cycle of telomerase), or by sufficiently distorting the substrate duplex causing misalignment of key catalytic groups. As telomerase is frequently over-expressed in cancer cells, the DRH duplex is a good therapeutic target. Thus we initiated a screening programme initially based on the National Cancer Institute (NCI) compound libraries which provide a high degree of structural diversity. Three novel scaffolds were identified in a Fluorescent Resonance Energy Transfer (FRET) based assay that showed at least a 5°C selective stabilization of the DNA/RNA hybrid duplex at 5μM ligand concentration. Medicinal chemistry modifications were then employed on these scaffolds to generate focused libraries of analogues with drug like properties. In total, 30 molecules were synthesized based on the identified scaffolds and subsequently screened against seven different DNA sequences including telomeric and promoter G-quadruplexes, and DRH sequences. A number of compounds showed selective DNA/RNA hybrid stabilization potential without significant affinity for G-quadruplex or duplex DNA sequences. These ligands provided hybrid DNA/RNA stabilization in the range of 5.2-9.5°C at 1μM ligand concentration. A second generation molecules where amides have been replaced by secondary amines are currently being synthesized to obtain SAR. Selected analogues from both compounds set are currently being evaluated in a variety of biological assays to confirm selective telomerase inhibition, and in cell based experiments to assess their potential as antitumour agents.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B204.

Citation Format: Mohammad K. Islam, David E. Thurston, Khondaker M. Rahman. Targeting key DNA/RNA heteroduplex of telomerase by small-molecule ligands. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B204.

Surgical outcome of laparoscopic and open surgery of pediatric inguinal hernia

Inguinal hernia repair is one of the most frequently performed surgical procedures in infants and young children. This prospective comparative study was conducted with initial experience in the department of pediatric surgery, Dhaka Shishu (children) hospital during the period of July 2007 to August 2008. We enrolled 62 children undergoing surgery for inguinal hernia, of which 30 underwent laparoscopic procedure (bilateral in 21, unilateral 9) and 32 open procedures (bilateral in 5, unilateral in 27). Mean±SD patient age was 5.92±2.11 months in laparoscopic group and 6.63±2.64 months in open group (p=0.264), 3 months to 5 years in both groups. Patients were studied under variables of operative time, duration of postoperative hospital stay & post operative complications. During laparoscopy a contralateral patent processus vaginalis of ≥2cm was noted and repaired peroperatively in 18 out of 27 children (66%), who were initially diagnosed as unilateral hernia. For unilateral repair mean±SD operative time was significantly longer in Group A (62.63±52.75) minutes compares to the Group B (29.37±9.40), p<0.001. On the contrary, for bilateral repair Mean±SD operative time was comparable between the two groups (64.65±49.70) minutes for laparoscopy & (35.65±11.53 minutes) for open herniotomy & P=0.01, that was not remarkably significant. The mean±SD post operative length of hospital stay (in hours) 36.00±32.7 hours in Group A compared to 29.97±11.82 hours in Group B which was not statically significant (p=0.342). The mean±SD follow up was 24.5±10.5 months in laparoscopic group (Group A) & 22.5±10.5 months in open group (Group B), p=0.251. Regarding post operative complication, in this study, contra lateral metachronous inguinal hernia (CMIH) manifested in none of the patient out of 27 (total unilateral repaired number) patients in laparoscopic group but contrary to this in open group 2 patients out of 27 had developed CMIH & p value was <0.05, which is statistically significant. There were 2 cases of scrotal hydrocele out of 30, observed in Group A whereas 1 case out of 32 in Group B, p=0.49, which was statistically insignificant. The scrotal hydrocele was lasted only for 2 days & resolved spontaneously. About recurrence after operation, our study noted that, 1 case (3.3%) out of 30 in laparoscopic group and 2 cases (6%) out of 32 in open surgery group had developed recurrent inguinal hernia in about one year follow up where p value was 0.459, & it was statistically insignificant. In this study, none of the patient had developed post operative testicular atrophy (due to any vas or vascular injury) or testicular ascend. So, overall this study result implies that, Laparoscopic herniotomy might be a safe and effective option as open herniotomy for the treatment of inguinal hernia in children but which one would be superior or best option it requires a large series of randomized trial.

A CROSS SECTIONAL STUDY ON FASCIOLA GIGANTICA AND GIGANTOCOTYLE EXPLANATUM BURDENS IN NATURALLY INFECTED BUFFALOES IN BANGLADESH

A cross sectional study on Fasciola gigantica and Gigantocotyle explanatum burdens in buffaloes in relation to their age, sex and health condition was carried out in the Laboratory of Parasitology, Bangladesh Agricultural University, Mymensingh, Bangladesh during the period from June to November 1997. A total of 460 faecal samples were examined to determine the egg per gram of faeces (epg) of F. gigantica. Higher epg was counted in female buffaloes (159.67 ± 6.80) than in males (153.24 ± 8.29). The epg counts were also found significantly (p < 0.01) higher in poor conditioned buffaloes (164.41 ± 6.67) than in buffaloes with normal health (128.57 ± 7.08). In relation to age, the young adult buffaloes were found to bear more parasitic burdens. The highest mean epg was recorded in the buffaloes of 2-3 years old (184.21 ± 19.14), followed by 3-5 years old (169.23 ± 30.77). The older buffaloes had relatively lower parasitic burden and the lowest mean epg was recorded in the growing buffaloes of up to 1 year old (125 ± 25.0). Examination of 106 livers from slaughtered buffaloes, revealed that the load of Fasciola gigantica and Gigantocotyle explanatum in the livers ranged from 13-424 (69.20 ± 6.46) and 41-427 (161.45 ± 10.79) respectively. In males the burden of F. gigantica (13-210) was lower than that of the females (15-424). The mean number of F. gigantica in the buffaloes of 5- 10 years old (100 ± 15.32) was significantly higher (p < 0.01) than those of the buffaloes of above 10 years old (52.92 ± 4.29). In case of single infection with F. gigantica, the mean number of parasites per liver was significantly (p < 0.05) higher (88.70 ± 11.48) than that of mixed infection cases (49.74 ± 4.20). Significantly (p < 0.01) higher number of G. explanatum was recovered from the buffaloes of 5-10 years old (207.53 ± 26.72) than from the buffaloes of above 10 years old (141.58 ± 9.23) and from single infected cases than from buffaloes with mixed infection. There were almost no differences in the number of both flukes in relation to sex of buffaloes. The length and breadth of immature and mature parasites were 5-15 min x 2-3 min and 16-72 mm x 4-14 mm respectively. No significant variation was found in the average size of F. gigantica in relation to the age and sex of buffaloes. But in case of single infection, the body size of mature F. gigantica (38.63 mm ± 0.38 mm x 9.96 mm ± 0.12 mm) was significantly (p < 0.05) higher than that of the mixed infection (33.68 mm ± 0.52 mm x 8.76 mm ± 0.07 mm) cases. This study fairly suggests that the young adult buffaloes harbour more F. gigantica parasites than their younger and older counterparts. The concomitant infection of buffaloes with F. gigantica and G. explanatum may hamper the parasites each other in establishing their infection and attaining growth in some way as measured by their burdens and morphological dimensions.

Laparoscopic versus open pyloromyotomy for infantile hypertropic pyloric stenosis: an early experience

This prospective comparative study was conducted with an initial experience in the Department of Pediatric Surgery, Dhaka Shishu (Children) Hospital during the period of December 2007 to January 2009, with the infants of 2-12 weeks age, diagnosed as Hypertrophic pyloric stenosis. Patients selection was done by simple random technique by means of lottery. For open pyloromyotomy conventional method & for laparoscopic pyloromyotomy three trocher techniques was applied. In this study, among 60 cases with infantile hypertrophic pyloric stenosis, 30 cases were finally selected for analysis irrespectively both in laparoscopic (Group A) & in open pyloromyotomy (Group B) group. Patients were studied under variables of operative time, required time of full feeds after operation, post operative hospital stay & both per and post operative complications. Regarding operative time, in Group A, mean±SD operating time (in minutes) was 61.59±51.73 whereas in Group B it was 28.33±8.40 & P value was 0.001. The result was statistically significant. The mean±SD time (in hours) of full feeds (ad libitum) was 35.00±31.70 hours in Group A compared to 28.95±10.99 hours in Group B and P value was found 0.342ns which was not statistically significant. On study of total length (in days) of post operative hospital stay, mean±SD was 3.09±2.25 & 2.58±1.15days in laparoscopic group & open pyloromyotomy group respectively. The p value was 0.355ns, which was statistically insignificant. Again, on study of complications, per operatively 6(19.5%) patients had developed haemorrage, 1(3.33%) had mucosal perforation & 4(13.36%) had developed duodenal serosal injury in laparoscopic group whereas only 1(3.33%) patient in open pyloromyotomy group had nothing else except simple hemorrhage. The p value (0.051ns) was also statistically insignificant. In regard to post operative complications, 2(6.6%) patients had developed wound hematoma, 2(6.6%) had wound infection, 1(3.33 %) had developed wound dehiscence and incisional hernia respectively in Group A. But in group B there was no subject with any complication. This result was also statistically insignificant. So, the overall study results denote that, laparoscopic pyloromyotomy would not be considered as a superior procedure or as safe as that of traditional open pyloromyotomy for the beginners.

Non-Hodgkin's lymphoma is a pathological lead point causing large gut (colo-colic varity) intussusception

Intussusception secondary to Primary Non-Hodgkin lymphoma presenting colo-colic variety is a very rare clinical entity and sometimes causing diagnostic dilemma due to non-specific, varied & wide spectrum presentation. In this study, a 9 years female child presented with recurrent, intermittent, colicky abdominal pain with occasional bilious vomiting, along with a left illiac fossa swelling & occasional per rectal bleeding and constipation for 3 months was clinically diagnosed as a case of recurrent obstructing intussusception. At laparotomy, a colo-colic intussusception with prolapsed intussusception was marked & finally on histopathology, she was diagnosed as a case of colo-colic variety of intussusception due to primary Non-Hodgkin lymphoma- a pathological lead point in mid transverse colon. After uneventful recovery of post operative period she was treated with combination chemotherapy accordingly & follow up was given up to 5 years. She had been found alright without any recurrence or organ involvement. The study focused on the avoidance of unusual delay in diagnosis as well as in proper management of rare variants of intussusception.

Applying usability heuristics to radiotherapy systems

BACKGROUND AND PURPOSE

Heuristic evaluations have been used to evaluate safety of medical devices by identifying and assessing usability issues. Since radiotherapy treatment delivery systems often consist of multiple complex user-interfaces, a heuristic evaluation was conducted to assess the potential safety issues of such a system.

MATERIAL AND METHODS

A heuristic evaluation was conducted to evaluate the treatment delivery system at Princess Margaret Hospital (Toronto, Canada). Two independent evaluators identified usability issues with the user-interfaces and rated the severity of each issue.

RESULTS

The evaluators identified 75 usability issues in total. Eighteen of them were rated as high severity, indicating the potential to have a major impact on patient safety. A majority of issues were found on the record and verify system, and many were associated with the patient setup process. While the hospital has processes in place to ensure patient safety, recommendations were developed to further mitigate the risks of potential consequences.

CONCLUSIONS

Heuristic evaluation is an efficient and inexpensive method that can be successfully applied to radiotherapy delivery systems to identify usability issues and improve patient safety. Although this study was conducted only at one site, the findings may have broad implications for the design of these systems.

Ultrasonographic evaluation of contralateral exploration of patent processus vaginalis in unilateral inguinal hernia

To see accuracy of ultrasound scan to detect patent processus vaginalis in padiatric patient. We investigated the presence of contralateral patent processus vaginalis (CPPV) by Ultrasound scan (US) in children with clinically diagnosed unilateral inguinal hernia. Thirty patents (17 boys and 13 Girls) with unilateral inguinal hernia underwent US examination using a 7.5 MHZ transducer. If a CPPV was visible as a hydrocele (inflow of peritoneal fluid) in to a processus vaginalis on straining, then US scanning was performed while the patient was at rest and while inducing straining by standing, coughing and or crying. A groin with hydrocele in the inguinal canal on straining was diagnosed as a CPPV and was explored bilaterally through surgery. The US findings were compared with surgical results. In 30 patients, 12 cases were diagnosed by US as patients with a CPPV, these patients underwent bilateral surgery. Eleven of 12 Cases were confirmed surgically as CPPV. From the findings of the present study it could be concluded that a PPV could be correctly detected by US in pediatric patients with the accuracy of 91.67%. US is a non invasive and accurate method for evaluating the presence of a PPV. Preoperative diagnosis of CPPV is important to remove the need for a second operation with patients presenting with unilateral inguinal hernia.

The use of human factors methods to identify and mitigate safety issues in radiation therapy

BACKGROUND AND PURPOSE

New radiation therapy technologies can enhance the quality of treatment and reduce error. However, the treatment process has become more complex, and radiation dose is not always delivered as intended. Using human factors methods, a radiotherapy treatment delivery process was evaluated, and a redesign was undertaken to determine the effect on system safety.

MATERIAL AND METHODS

An ethnographic field study and workflow analysis was conducted to identify human factors issues of the treatment delivery process. To address specific issues, components of the user interface were redesigned through a user-centered approach. Sixteen radiation therapy students were then used to experimentally evaluate the redesigned system through a usability test to determine the effectiveness in mitigating use errors.

RESULTS

According to findings from the usability test, the redesigned system successfully reduced the error rates of two common errors (p<.04 and p<.01). It also improved the mean task completion time by 5.5% (p<.02) and achieved a higher level of user satisfaction.

CONCLUSIONS

These findings demonstrated the importance and benefits of applying human factors methods in the design of radiation therapy systems. Many other opportunities still exist to improve patient safety in this area using human factors methods.

Small field electron beam dosimetry using MOSFET detector

The dosimetry of very small electron fields can be challenging due to relative shifts in percent depth‐dose curves, including the location of dmax, and lack of lateral electronic equilibrium in an ion chamber when placed in the beam. Conventionally a small parallel plate chamber or film is utilized to perform small field electron beam dosimetry. Since modern radiotherapy departments are becoming filmless in favor of electronic imaging, an alternate and readily available clinical dosimeter needs to be explored. We have studied the performance of MOSFET as a relative dosimeter in small field electron beams. The reproducibility, linearity and sensitivity of a high‐sensitivity microMOSFET were investigated for clinical electron beams. In addition, the percent depth doses, output factors and profiles have been measured in a water tank with MOSFET and compared with those measured by an ion chamber for a range of field sizes from 1 cm diameter to 10 cm× 10 cm for 6, 12, 16 and 20 MeV beams. Similar comparative measurements were also performed with MOSFET and films in solid water phantom. The MOSFET sensitivity was found to be practically constant over the range of field sizes investigated. The dose response was found to be linear and reproducible (within ±1% for 100 cGy). An excellent agreement was observed among the central axis depth dose curves measured using MOSFET, film and ion chamber. The output factors measured with MOSFET for small fields agreed to within 3% with those measured by film dosimetry. Overall results indicate that MOSFET can be utilized to perform dosimetry for small field electron beam.

PACS number: 87.55.Qr

Comparison of post operative morbidity between laparoscopic and open appendectomy in children

This prospective comparative study was conducted in the department of Pediatric Surgery, Dhaka Shishu (children) Hospital during the period of June 2007 to September 2008 with the children of <12 years, diagnosed as acute Appendicitis. Patient selection was done by simple random technique by means of lottery. For open Appendectomy (OA) conventional method & for Laparoscopic Appendectomy (LA) 3 trocher technique was applied. Data was analyzed with the help of SPSS version 10. In this study 60 cases with acute Appendicitis including both gender were studied by two groups, group-A include 30 cases for laparoscopic and group-B include 30 cases for open appendectomy. Postoperative pain was assessed in both groups by using FLACC scale and compared at 1st 6-hours, 24 hours, 72 hours, 96 hours & at day 7. At 1st 6-hours, most of the children 24(80%) of group A had moderate pain whereas 17(56.7%) children of group B had severe pain (p<0.001). At 24 hours most of the patient 17(56.7%) of group A had mild pain compared to 27 (90%) patients of group B had moderate pain (p<0.0001). At 48 hours in group A most of the children 23(76.7%) had mild pain compared to moderate pain in 18(60%) children of group B (p<0.0001). Subsequently at 72 hours and at 96 hours most of the patients of LA group were free of pain compared to OA group. At final follow-up on day 7, 29(96.7%) children of group A had no pain compared to 26(86.7%) of group B. Regarding analgesics requirement both qualitative & quantitative requirements of analgesics were less in LA group than OA group. About post operative wound infection in group A only 1(3.3%) case had developed post operative wound infection whereas in group B 7(23.3 %) cases had. The mean (+/-SD) of post operative length of hospital stay was 52.00+/-11.62 (range 48-96) hours for group A and 76.00+/-12.74 (range 48-96) hours for group B children (p<0.001). Laparoscopic Appendectomy is more effective, preferable & superior procedure than that of open Appendectomy to reduce the post operative morbidity in children undergone appendectomy for acute appendicitis.

Assessment and management of radiotherapy beam intersections with the treatment couch

The impact of the treatment couch on a radiotherapy plan is rarely fully assessed during the treatment planning process. Incorporating a couch model into the treatment planning system (TPS) enables the planner to avoid or dosimetrically evaluate beam-couch intersections. In this work, we demonstrate how existing TPS tools can be used to establish this capability and assess the accuracy and effectiveness of the system through dose measurements and planning studies. Such capabilities may be particularly relevant for the planning of arc therapies.Treatment couch top models were introduced into a TPS by fusing their CT image sets with the patient CT dataset. Regions of interest characterizing couch elements were then imported and assigned appropriate densities in the TPS. Measurements in phantom agreed with TPS calculations to within 2% dose and 1 degrees gantry rotation. To clinically validate the model, a retrospective study was performed on patient plans that posed difficulties in beam-couch intersection during setup. Beam-couch intersection caused up to a 3% reduction in PTV coverage, defined by the 95% of the prescribed dose, and up to a 1% reduction in mean CTV coverage. Dose compensation strategies for IMRT treatments with beams passing through couch elements were investigated using a four-field IMRT plan with three beams passing through couch elements. In this study, ignoring couch effects resulted in point dose reductions of 8 +/- 3%.A methodology for incorporating detailed couch characteristics into a TPS has been established and explored. The method can be used to predict beam-couch intersections during planning, potentially eliminating the need for pretreatment appointments. Alternatively, if a beam-couch intersection problem arises, the impact of the couch can be assessed on a case-by-case basis and a clinical decision made based on full dosimetric information.

Molecular characterization of a blood-induced serine carboxypeptidase from the ixodid tick Haemaphysalis longicornis

Ticks feed exclusively on blood to obtain their nutrients, but the gene products that mediate digestion processes in ticks remain unknown. We report the molecular characterization and possible function of a serine carboxypeptidase (HlSCP1) identified in the midgut of the hard tick Haemaphysalis longicornis. HlSCP1 consists of 473 amino acids with a peptidase S10 family domain and shows structural similarity with serine carboxypeptidases reported from other arthropods, yeasts, plants and mammals. Endogenous HlSCP1 is strongly expressed in the midgut and is supposed to localize at lysosomal vacuoles and on the surface of epithelial cells. Endogenous HlSCP1, identified as a 53 kDa protein with pI value of 7.5, was detected in the membrane/organelle fraction isolated from the midgut, and its expression was upregulated during the course of blood-feeding. Enzymatic functional assays revealed that a recombinant HlSCP1 (rHlSCP1) expressed in yeast efficiently hydrolyzed the synthetic substrates specific for cathepsin A and thiol protease over a broad range of pH and temperature values. Furthermore, rHlSCP1 was shown to cleave hemoglobin, a major component of the blood-meal. Our results suggest that HlSCP1 may play a vital role in the digestion of the host's blood-meal.

Reduction of vanadium(V) to vanadium(IV) by NADPH, and vanadium(IV) to vanadium(III) by cysteine methyl ester in the presence of biologically relevant ligands

To better understand the mechanism of vanadium reduction in ascidians, we examined the reduction of vanadium(V) to vanadium(IV) by NADPH and the reduction of vanadium(IV) to vanadium(III) by L-cysteine methyl ester (CysME). UV-vis and electron paramagnetic resonance spectroscopic studies indicated that in the presence of several biologically relevant ligands vanadium(V) and vanadium(IV) were reduced by NADPH and CysME, respectively. Specifically, NADPH directly reduced vanadium(V) to vanadium(IV) with the assistance of ligands that have a formation constant with vanadium(IV) of greater than 7. Also, glycylhistidine and glycylaspartic acid were found to assist the reduction of vanadium(IV) to vanadium(III) by CysME.

Urogenital anomalies associated with anorectal malformations in children

The urogenital tract is the most severe and common site of associated defects in anorectal malformations (ARM). Urogenital anomalies and their complications significantly increase the morbidity in these children after the ARM is corrected. The purpose of this study was to estimate the incidence of different types of urogenital anomalies with various types of anorectal malformations and to discuss the possible management and outcome. A retrospective study of patients with ARM and associated urogenital abnormalities admitted in the department of paediatric surgery of Sylhet MAG Osmani Medical College Hospital between 1998 and 2002 was undertaken. A total of 155 patients with Anorectal malformations were admitted of which 47 (30.32%) patients had associated anomalies involving other systems. Urogenital abnormalities were found in 25 (16.13%) patients. Patients of Anorectal malformations with urogenital abnormalities require careful assessment and well-timed intervention to minimize the morbidity.

Fluoride exposure inhibits protein expression and enzyme activity in the lung-stage larvae ofAscaris suum

Sodium fluoride (NaF) is an anion that has been previously shown to block the moulting process ofAscaris suumlarvae. This study describes moulting and development-specific protein expression profiles ofA. suumlung-stage L3 (AsLL3) following NaF exposure. AsLL3s cultured in the presence or absence of NaF were prepared for protein analysis using two-dimensional (2D) electrophoresis. NaF exposure inhibited at least 22 proteins in AsLL3 compared with moulted larvae (i.e. AsLL4). A further comparison of AsLL4 with those of pre-cultured AsLL3 and NaF-exposed AsLL3 revealed 8 stage-specifically and 4 over-expressed proteins. Immunoblot analysis revealed an inhibition by NaF of 19 immunoreactive proteins. Enzyme assay and immunochemical data showed an inhibition of the moulting-specific inorganic pyrophosphatase activity by 41% and a decreased expression in NaF-treated larvae, indicating its significance in the moulting process. A protein spot associated with NaF inhibition was isolated and identified by peptide mass spectrometry and bioinformatics approaches to be a member of 3–hydroxyacyl–CoA dehydrogenase/short-chain dehydrogenase enzyme families. These results have implications for the identification of proteins specific to the moulting process as potential chemotherapeutic targets.

Patient dose from kilovoltage cone beam computed tomography imaging in radiation therapy

Kilovoltage cone-beam computerized tomography (kV-CBCT) systems integrated into the gantry of linear accelerators can be used to acquire high-resolution volumetric images of the patient in the treatment position. Using on-line software and hardware, patient position can be determined accurately with a high degree of precision and, subsequently, set-up parameters can be adjusted to deliver the intended treatment. While the patient dose due to a single volumetric imaging acquisition is small compared to the therapy dose, repeated and daily image guidance procedures can lead to substantial dose to normal tissue. The dosimetric properties of a clinical CBCT system have been studied on an Elekta linear accelerator (Synergy RP, XVI system) and additional measurements performed on a laboratory system with identical geometry. Dose measurements were performed with an ion chamber and MOSFET detectors at the center, periphery, and surface of 30 and 16-cm-diam cylindrical shaped water phantoms, as a function of x-ray energy and longitudinal field-of-view (FOV) settings of 5,10,15, and 26 cm. The measurements were performed for full 360 degrees CBCT acquisition as well as for half-rotation scans for 120 kVp beams using the 30-cm-diam phantom. The dose at the center and surface of the body phantom were determined to be 1.6 and 2.3 cGy for a typical imaging protocol, using full rotation scan, with a technique setting of 120 kVp and 660 mAs. The results of our measurements have been presented in terms of a dose conversion factor fCBCT, expressed in cGy/R. These factors depend on beam quality and phantom size as well as on scan geometry and can be utilized to estimate dose for any arbitrary mAs setting and reference exposure rate of the x-ray tube at standard distance. The results demonstrate the opportunity to manipulate the scanning parameters to reduce the dose to the patient by employing lower energy (kVp) beams, smaller FOV, or by using half-rotation scan.

Molecular cloning and partial characterization of a nematode-specific 24 kDa protein fromAscaris suum

The cloning and molecular characterization of a cDNA encodingAscaris suum24 kDa antigen (As24) are described. The cDNA sequence consists of 853 bp with an open reading frame coding for a protein of 147 amino acids with an inferred signal peptide of 19 amino acids. The predicted molecular mass and pI were 16 kDa and 8·35 respectively. The endogenous protein in adultA. suumwas 24 kDa with the expected pI. A search of the public databases revealed over 50% homology with proteins from filarial parasites but not to other known proteins, suggesting that As24 is a nematode-specific protein. Immunohistochemical studies using polyclonal antibodies raised againstEscherichia coli-expressed recombinant As24 demonstrated that the endogenous As24 proteins were intensely localized in unembryonated eggs within the uterus, uterine and gut epithelium, muscle tissues and in the hypodermis of an adult femaleA. suum. Endogenous As24 was expressed throughoutA. suumdevelopment and was detected in the excretory/secretory products by immunoblot analysis. Importantly, a homologous protein(s) was detected inAscarisfrom human andToxocara canisfrom dog, suggesting that As24 is a nematode-specific protein.

Characterization of the protective response against a homologous challenge infection with Strongyloides venezuelensis in rats

The protective response in rats against a homologous challenge infection with Strongyloides venezuelensis was characterized. In an initial infection with 1000 filariform larvae and migrating larvae (L(3)) of S. venezuelensis, the population of L(3) in the lungs on day 3 postinfection (PI), and that of adult worms in the small intestine on day 7 PI, were 180.8+/-14.5 and 336.8+/-70.7, respectively. The latter were gradually expelled towards day 42 PI. After the initial infection, the rats developed strong immunity against a homologous challenge infection as manifested by a marked reduction in worm populations, stunted body length and width, damage to reproductive organs, impaired egg production and rapid expulsion of the worms by day 14 after challenge. Expulsion of the worms was preceded by a significantly elevated (P<0.05) peripheral blood eosinophil (PBE) count, both in the initial (200.0+/-26.5 x 10(3)ml) and the challenge infection (400.9+/-165.4 x 10(3)ml). These findings suggest that rats acquire strong homologous immunity following initial exposure to S. venezuelensis. It is suggested that PBEs are involved in worm expulsion. A major target of these effector mechanisms is the reproductive system of S. venezuelensis.

Formal and informal care for people with dementia: factors associated with service receipt

Details of service receipt by 132 people diagnosed with dementia and their carers were collected in South London (boroughs of Lewisham, Camberwell, Southwark and Croydon), a geographical area served by several health and social care providers. The data collected included the Caregiver Activity Survey, which details the informal care given. This paper reports the formal and informal services received by the people with dementia at entry to the study. The amount of time spent on specific caring tasks by all informal carers of people with dementia averaged seven hours per week, but was significantly higher for co-resident carers, even when controlling for the level of dependency of the person cared-for. The odds ratios of receipt of formal services are given, according to where people were living: in the community or residential care, with co-resident carers or alone.

Dose to radiation therapists from activation at high-energy accelerators used for conventional and intensity-modulated radiation therapy

The increased beam-on times which characterize intensity-modulated radiation therapy (IMRT) could lead to an increase in the dose received by radiation therapists due to induced activity. To examine this, gamma ray spectrometry was used to identify the major isotopes responsible for activation at a representative location in the treatment room of an 18 MV accelerator (Varian Clinac 21EX). These were found to be 28Al, 56Mn, and 24Na. The decay of the dose rate measured at this location following irradiation was analyzed in terms of the known half-lives to yield saturation dose rates of 9.6, 12.4, and 6.2 microSv/h, respectively. A formalism was developed to estimate activation dose (microSv/week) due to successive patient irradiation cycles, characterized by the number of 18 MV fractions per week, F, the number of MU per fraction, M, the in-room time between fractions, td (min), and the treatment delivery time t'r (min). The results are represented by the sum of two formulas, one for the dose from 28Al 1.8 x 10(-3) F M (1-e(-03t'(r))/t'r and one for the dose from the other isotopes approximately 1.1 x 10(-6) F(1.7) Mt(d). For conventional therapy doses are about 60 microSv/week for an 18 MV workload of 60,000 MU/week. Irradiation for QA purposes can significantly increase the dose. For IMRT as currently practiced, lengthy treatment delivery times limit the number of fractions that can be delivered per week and hence limit the dose to values similar to those in conventional therapy. However for an IMRT regime designed to maximize patient throughput, doses up to 330 microSv/week could be expected. To reduce dose it is recommended that IMRT treatments should be delivered at energies lower than 18 MV, that in multienergy IMRT, high-energy treatments should be scheduled in the latter part of the day, and that equipment manufacturers should strive to minimize activation in the design of high-energy accelerators.

Congenital Penile Urethrocutaneous Fistula

Congenital Penile Urethrocutaneous Fistula (CPUF) is an extremely rare anomaly. Commonly congenital urethrocutaneous fistulae are associated with anorectal anomalies and urethral duplication. The posterior urethra is the part, which is mostly affected. To the best of our knowledge, only 11 such cases have been reported so far in the English literature. A case of CPUF with a short review of literature.

A simplified shielding approach for limiting fetal dose during radiation therapy of pregnant patients

PURPOSE

To investigate the effectiveness of a simple and practical shielding device to reduce fetal dose for a patient undergoing radiation therapy of nasopharyngeal carcinoma.

METHODS AND MATERIALS

Using 5-cm-thick lead bricks and a heavy-duty steel cart, a 50 x 50-cm portable shield was designed and fabricated to reduce fetal dose due to collimator scatter and head leakage radiation. With the gantry at 90 degrees /270 degrees the shield can be easily positioned between the machine head and the fetus to reduce peripheral dose. Dose measurements for 6-MV X-rays and 9-MeV electrons have been made, utilizing a Rando phantom, to quantify the effect of the shield.

RESULTS

Measurements show that the peripheral dose to the fetus can be reduced by 60% when the simple shielding device is used.

Examination of gastrointestinal helminth in livestock grazing in grassland of Bangladesh

To determine association of grassland with parasitic diseases of livestock in Bangladesh, the 'Tracer' animals (two cow calves and two goats) were released for a month in a grassland used for communal grazing of livestock near school premise in Kanthal, Trishal, Mymensingh, Bangladesh. After slaughtering of the tracer animals, their gastrointestinal tract examination revealed six species of nematode and one cestode. The nematode species were Haemonchus contortus, Trichostrongylus axei, Mecistocirrus digitatus, Oesophagostomum spp., Trichuris spp. and Bunostomum sp. The cestode was one of the genus Moniezia. With this preliminary study, grasslands are thought to be one of the main sources of gastrointestinal parasitic diseases of livestock in Bangladesh.

Partial cross-resistance between Strongyloides venezuelensis and Nippostrongylus brasiliensis in rats

Rats were immunized through an initial infection with 1,000 filariform larvae (L3) of Nippostrongylus brasiliensis and after complete expulsion of worms they were challenged with 1,000 L3 of Strongyloides venezuelensis to investigate whether cross-resistance developed against a heterologous parasite. Nippostrongylus brasiliensis-immunized rats developed a partial cross-resistance against S. venezuelensis migrating larvae (MSL3) in the lungs and adult worms in the small intestine. The population of MSL3 in the lungs were significantly lower (P < 0.05) in immunized rats (22.0 +/- 7.4) compared with controls (105.0 +/- 27.6). The populations of adult worms, egg output and fecundity were initially decreased but from day 14 post-challenge they did not show any significant difference between immunized and control rats. However, the length of worm in immunized rat was revealed as retardation. Peripheral blood eosinophilia was significantly decreased (P < 0.05) on day 7 post-challenge and then gradually increased, which peaked on day 42 post-challenge when most of the worms were expelled. These results suggest that peripheral blood eosinophilia is strongly involved in the worm establishment and expulsion mechanisms.

The potential for social mobilisation in Bangladesh: the organisation and functioning of two health insurance schemes

Health insurance schemes are usually assessed according to technical indicators. This approach, however, neglects the dynamic perspective of insurance schemes as an element of people's mobilisation for participation in organising and managing health care delivery and financing. The first part of this paper describes the technical performance and the level of community involvement in management of the two largest health insurance schemes in Bangladesh, both in the rural areas and in the non-government sector. Part two discusses these achievements in light of the schemes' potential role as a mechanism for people's management of health care. A review of documents and key-informant interviews were conducted. Key findings include that (1) subscribers currently are not actively participating in scheme management. However, existing family groups, involved in credit programmes may serve as entry-points for interaction. This is sustained by the 'natural link' between health insurance as a means of spreading the risks of treatment costs and credit programmes as a means of decreasing the relative impact of illness on household income. (2) The schemes' role could be further enhanced, by improving their technical performance and applying health care systems elements with the input of all partners involved. These issues are avoidance of service duplication with other providers; better protection of the poorer households; inclusion of hospital care in the coverage package; simplification of scheme administration by introduction of episode-based co-payments instead of the current itemised ones and concentrating the schemes at the level of community-based services, which may be self-financed and also self-managed by the community, given available sensitisation, training and interaction. A shift to episode-based co-payments would also introduce solidarity among patients and among individuals at higher risk, such as pregnant women and under-fives. Finally, action-research is needed to document the process of increased community involvement.