Endoscopic Transnasal Repair of Cerebrospinal Fluid Leakage: Experience in BSMMU

Endoscopic transnasal repair of CSF rhinorrhoea is gaining popularity around the world because of its tremendous success rate but it depends on defect site, size, technique of repair, experiences of surgeon and also patient's profile. Aim of this study was to analysis of surgical outcome of endoscopic transnasal repair of CSF rhinorrhoea. A retrospective study carried out in the department of ENT and Head neck surgery at Bangabandhu Sheikh Mujib Medical University (BSMMU) from January 2018 to December 2019. Of the total of 24 patients 16(66.0%) were female and 8(33.0%) males. The commonest site of the leak was in the cribriform plate in 18(75.3%) followed by 5(20.8%) in the fovea ethmoidalis, and 1(4.0%) in the sphenoid sinus, the overall success rate of this series with first surgical procedure was 95.83% and 100.0% with a second procedure. Meticulous pre-operative evaluation, proper identification of leakage site, choice of graft materials and surgical technique are keys to attaining excellent results.

Complete Heparin Reversal by Protamine during Off-Pump Coronary Artery Bypass Surgery (OPCAB): A Necessity or Myth?

In our country majority of the coronary artery bypass surgery (CABG) are done off-pump and was reported having excellent clinical outcome along with cost efficiency by various investigators. Heparin is commonly used as most effective anticoagulant, and protamine sulfate is now generally used to reverse the anticoagulant action of heparin. While under dosing of protamine may result in incomplete heparin reversal and prolonged anticoagulation, protamine overdosing is associated with impaired clot formation exerted by the intrinsic anti-coagulation properties of protamine itself, moreover protamine administration is associated with mild to severe cardiovascular and pulmonary complications. Apart from traditional full neutralization of heparin now-a-days, half dose protamine was also introduced showing good outcome regarding lower activated clotting time (ACT), overall, less surgical bleeding with less transfusion. This comparative study was designed to detect differences between traditional and decreased protamine dosing in Off-Pump Coronary Artery Bypass (OPCAB) surgery. Four hundred (400) patients who underwent Off-Pump Coronary Artery Bypass Surgery (OPCAB) surgery at our institution over a period of 12 months were analyzed and were divided into two groups. Group A- received 0.5mg of protamine per 100 unit of heparin; Group B-received 1.0mg of protamine per 100 unit of heparin. ACT, blood loss, hemoglobin and platelet count units of blood and blood product transfusion requirements, clinical outcome and hospital stay were assessed in each patient. This study showed that 0.5mg of protamine per 100 unit of heparin was always able to reverse the anticoagulant effect of heparin with no significant difference in hemodynamic parameters, amount of blood loss and requirements of blood transfusion in between the groups. A standard protamine dosing formula (protamine-heparin at ratio of 1:1) adequate for on-pump cardiac surgical procedures significantly overestimates protamine requirements for OPCAB. Patients treated with decreased protamine do not appear to have adverse outcomes in terms of post-operative bleeding.

A Case Report of Porphyria Cutanea Tarda with Hepatitis-C Virus Co-infection

Porphyria cutanea tarda is a rare disorder of heme metabolism due to deficiency of the enzyme uroporphyrinogen decarboxylase which is manifested as some typical dermatological features and hepatic dysfunction. The Hepatitis-C virus co-infection is common and it can be aggravated by other environmental factors. We report a case of porphyria cutanea tarda in a 37-year-old woman, who presented with recurrent skin blisters and has concomitant Hepatitis-C virus infection. She was taking oestrogen containing oral contraceptive pill for a long duration. The diagnosis of porphyria cutanea tarda was considered on the basis of clinical features and high level of urine porphyrin level. She was put on hydroxychloroquine and combination drugs for Hepatitis-C virus with significant improvement after 3 months of therapy.

Residue level and health risk assessment of organophosphorus pesticides in country bean and bitter gourd collected from Cumilla, Bangladesh

Organophosphorus pesticides are one of the most commonly used pesticide classes in agriculture in the management of insect pests due to their high efficacy. The extensive use of organophosphorus pesticides can contaminate both the atmosphere and food, which may lead to health problems. In this study, the residue level of organophosphorus pesticides, and their health risk assessment was evaluated on country bean and bitter gourd. Out of forty analysed samples of the country bean, two samples contained multiple residues, seven samples contained single residue. On the other hand, out of forty samples of bitter gourd, one sample contained multiple residues and three samples contained single residue. Among the organophosphorus pesticides, diazinon was the most frequently detected organophosphorus pesticide in country bean and bitter gourd. The highest short-term risks or acute risk (aHI) was below 1.83%, and the highest long-term risk or chronic risk (HQs) was below 10.46% for the country bean and bitter gourd, respectively. Short- and long-term risk assessment results showed that the intake risks of country bean and bitter gourd were acceptable. The health hazard results showed that country bean and bitter gourd consumption in Cumilla, Bangladesh does not pose an acute or chronic risk to human health. However, a routine monitoring system must be established to control the contamination of vegetables with pesticides.

Outcome of Management of Liver Abscess by Surgical Approach in a Tertiary Care Hospital

Liver abscess is a serious, life threatening condition. A recent development in the management of liver abscesses, facilitated by advances in diagnostic and interventional radiology, has decreased mortality rates. The purpose of this study is to search for the clinical presentations and surgical outcomes of liver abscess in our country. The markers of the outcome are mortality, duration of hospital stay and complications such as wound infection, residual disease following surgery, biliary leakage, intra abdominal abscess formation. This observational cross sectional study was conducted in Mymensingh Medical College & Hospital (MMCH), Bangladesh for 12 months from 1st January 2017 to 31st December 2017. Total 25 patients presenting with the features of liver abscess were included in this study by convenient and purposive sampling according to the inclusion and exclusion criteria. Surgical principles of liver abscess management were applied and outcomes were observed. The patients were diagnosed on the basis of clinical feature, findings of abdominal ultrasound and occasionally by doing CT scan. Most of the patients (28%) were in the age group of 51-60 years. Regarding sex distribution majority of the patients (64%) was male. Most of patients presented with fever (92%), anorexia and vomiting (32%), upper abdominal pain (84%). Hepatomegaly and reactive pleural effusion are the important findings present in 9(36%) and 8(32%) patients respectively. Size of the liver abscess was more than 5cm in 72% patients. Among the patients right lobe was predominantly involved. It was found during laparotomy that 4 patients (16%) had spontaneous rupture of abscess into peritoneal cavity. One (4%) patient developed biliary leakage after surgical drainage. No intra abdominal abscess or residual diseases was observed after surgery. Among the patients 24% developed wound infection. The overall mortality rate was 12%. The median length of hospital stay was 8 days (range: 1-15 days). Outcome of surgical drainage of liver abscess in tertiary care hospital of our country shows satisfactory result. So, patients with large multiple liver abscess, septic shock, failures of percutaneous drainage should be treated by early open surgical intervention.

Outcome of Closed Reduction and Internal Fixation by Titanium Elastic Nailing for Fracture Shaft of Femur in Children

Femoral fractures are frequent in the pediatric population. Treatment options are based on the patient's age, fracture pattern, type of trauma and associated soft tissue injury. The traditional treatment method for pediatric femoral shaft fracture has been traction and spica casting. The immediate spica cast is safe and effective for children up to 6 years of age with isolated femoral fracture and acceptable reduction. Patients between 6 and 10 years of age can also be treated with spica casting with or without traction. This prospective study was done in the department of Orthopaedics, Mymensingh Medical College Hospital, Mymensingh, Bangladesh form from July 2015 to June 2019 to evaluate the outcome of closed reduction and internal fixation by titanium elastic nailing for fracture shaft of femur. Twenty patients, all presenting with fresh diaphyseal fractures of femur, treated with closed reduction and internal fixation by titanium elastic nailing. These patients were prospectively evaluated over a period of at least 18 months. Fractures were classified according to Association of Orthopaedics (AO) classification of shaft of femur fractures. According to AO classification, all were A1, A2, A3 fractures. Average age of the patients was 11±2.7 years; range was 6 to 16 years. There were 15 males and 5 females. Out of 20 cases treated with this method, stable fixation and union was achieved in all of them. Radiological union was achieved at an average of 10±2.3 weeks (8-15 weeks). The results were excellent in twelve patients (60%), successful in five (25%) and poor in three patients (15%) as per the scoring criteria for TEN. The effective treatment of diaphyseal fractures of the femur is intramedullary fixation by titanium elastic nailing in patients of the 6-16 years age group.

Anterior Cruciate Ligament Reconstruction using Bone Patellar Tendon Bone Autograft in ACL Deficient Knee

More than 120,000 anterior cruciate ligament (ACL) injuries occur every year in the United States, mostly during the high school and college years. The incidence of these injuries is slowly increasing, especially in females. This is likely caused by their increasing participation in high school and other organized sports. In addition, several studies have shown that female athletes are at an increased risk of ACL injury in sex comparable sports. The goal of this study was to evaluate the functional outcome of Arthroscopic anterior cruciate ligament reconstruction using Bone-Patellar tendon- Bone autograft. 25 patients with chronic ACL deficient knee presenting to Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh from January 2018 to December 2019 were included in the study. The patients with severe osteoarthritis (OA) knee, local active infection and systemic disease, intraarticular fracture of knee that might influence the study results were excluded from the study. Bone patellar tendon bone graft was harvested from ipsilateral knee. The patient was followed till 6 months with specified program of rehabilitation. Results were evaluated by an independent examiner using radiography, subjective and objective evaluation. Assessment using Lysholm's score was 50 (42-63) preoperatively and 90.8 (63-97) at the latest follow up (p<0.005). No patient complained of instability at latest follow up. The quadriceps muscle showed atrophy at final follow-up. Five Patients complained of anterior knee pain. We found no graft displacement on follow up radiographs. Osteo-integration occurred in all cases. ACLR with a BPTB graft can stabilize the knee without loss of motion by closely mimicking the native ACL without any hazards and additional complications. It is useful in high demand patients and cost effective option with high patient satisfaction rate for reconstruction of ACL.

Efficacy of Intra-peritoneal Tramadol Instillation for Postoperative Pain Management after Laparoscopic Cholecystectomy

Gall stone disease is one of the most common conditions encountered in general surgical practices in adult population. The gold standard treatment for symptomatic gall stone disease is laparoscopic cholecystectomy. It results in less post-operative pain as compared to open cholecystectomy but post-operative pain may be mild, moderate or even severe in some patients. This Randomized control trail was conducted to In-patient department of Surgery, Mymensingh Medical College & Hospital (MMCH), Mymensingh, Bangladesh from April 2018 to September 2018. It was undertaken to evaluate the analgesic effect of intra-peritoneal tramadol instillation in patients undergoing laparoscopic cholecystectomy. Total 70 patients with symptomatic gallstone disease undergoing laparoscopic cholecystectomy were randomized equally in two groups. Then patients were selected in according to the inclusion and exclusion criteria. In first group (Group A), patients were received intra-peritoneal tramadol 100mg (diluted in 20.0ml distilled water). Sprayed 10.0ml diluted tramadol into the sub diaphragmatic area, 5.0ml into the area of gall bladder bed and 5.0ml into the space between the liver and kidney under direct vision just before removal of trocars. In second group (Group B) the conventional operative procedure was followed. Postoperatively, patient was extubated and shifted to recovery room. Data recorded and analyzed, such as post-operative pain score at 1, 4, 8, and 24 hour; cumulative 1, 8 and 24 hour analgesic consumption. In addition that postoperative hospital period monitoring of heart rate, blood pressure, respiratory rate, temperature at 0, 4, 8, 24 hours was also analyzed. Intensity of pain was assessed by Visual Analogue Scale (VAS) scoring system. Patients showed a VAS ≥3 or patients who requested for analgesia was administrated a supplemental dose of analgesic. In the present study the mean pain scores in Group A were found to be low at1hourpost-operative was 0.60±0.56 and there was a gradual increase in score in respect of time interval with peak of 2.07±0.91 at 24 hours. Whereas, in Group B the mean pain scores immediate post-operative period were at its peak was, 2.50±0.82 which decreased to 1.30±0.84 at 1 hour and further there was rise at 4 hours (2.10±0.71) and 24 hours (2.33±0.0.71). But at any point of time the mean VAS remained significantly low (p<0.050) in patients with Group A compared to Group B except at 1st 24 hours (p=0.210). Intra-peritoneal instillation of tramadol for postoperative pain control in laparoscopic cholecystectomy has beneficial effect in terms of postoperative pain relief following laparoscopic cholecystectomy.

Isolation of pathogenic microorganisms and determination of their antibiotic resistance patterns collected from different bakery products of Dhaka city

Bakery products play an important part in the diet of daily life and provide vital nutrients to human. But pathogenic microorganisms may get entry to bakery items through improper handling and storage which may lead some disease to consumers. For this reason, the objective of this study was to detect pathogenic bacteria in different bakery products collected from different places of Dhaka city. In this study, commonly consumed bakery items such as sweets, biscuit, cake and bread samples were collected from different locations for the detection of pathogenic microorganism. Here, all the samples were found to be contaminated huge microbial count up to 106 CFU/g. Klebsiella spp. and Pseudomonas spp. were most predominate among all. On the other hand, Escherichia coli was totally absent in all the samples. This result indicated that bakery products prepared under unhygienic environments and which may serve as a reservoir of various pathogenic bacteria and most of them were showed resistance against common antibiotics. To ensure the health safety of consumer’s government should take necessary actions to educated food handlers.

Knowledge and Practice of Hepatitis B among Biological and Biomedical Sciences Students in a Public University of Bangladesh

A large numbers of biological and biomedical sciences students intricate themselves in health care professions, which makes them vulnerable to occupational exposure of Hepatitis B. This study aimed to determine the level of knowledge and practice of hepatitis B among biological and biomedical sciences students in a public university of Bangladesh. A cross-sectional study was conducted in Noakhali Science and Technology University (NSTU), Noakhali, Bangladesh from March 2017 to July 2017. Data was collected from students through purposive sampling technique using self-administered structured questionnaire and analyzed by using IBM SPSS 23.0. Out of the 303 participants, 213(70.3%) were within adequate knowledge range and 30(9.9%) of the students were in good practice range. Only 71(23.14%) of the students were fully vaccinated against Hepatitis B. Knowledge level of Participant's were significantly associated with their age and father's education. The practice level was significantly associated with age and all educational variables. Moreover, significant positive but weak linear correlations between knowledge and practice score were identified. The study indicates adequate knowledge, but poor practice of students towards HB. Thus, we recommend all students to implement their knowledge in real life and should be vaccinated prior to entry into health profession.

Plant growth promotion and suppression of bacterial leaf blight in rice by Paenibacillus polymyxa Sx3

The effects and mechanisms of Paenibacillus polymyxa Sx3 on growth promotion and the suppression of bacterial leaf blight in rice were evaluated in this study. The results from a plate assay indicated that Sx3 inhibited the growth of 20 strains of Xanthomonas oryzae pv. oryzae (Xoo). Rice seedling experiments indicated that Sx3 promoted plant growth and suppressed bacterial leaf blight. In addition, bacteriological tests showed that Sx3 was able to fix nitrogen, solubilize phosphate and produce indole acetic acid, indicating that various mechanisms may be involved in the growth promotion by Sx3. The culture filtrate of P. polymyxa Sx3 reduced bacterial growth, biofilm formation and disrupted the cell morphology of Xoo strain GZ 0005, as indicated by the transmission and scanning electron microscopic observations. In addition, MALDI-TOF MS analysis revealed that Sx3 could biosynthesize two types of secondary metabolites fusaricidins and polymyxin P. In summary, this study clearly indicated that P. polymyxa Sx3 has strong in vitro and in vivo antagonistic activity against Xoo, which may be at least partially attributed to its production of secondary metabolites. SIGNIFICANCE AND IMPACT OF THE STUDY: Antagonistic bacteria can grow well in their originating environment. However, it is unclear whether antagonistic bacteria were able to survive in different ecological environments. This study revealed that Paenibacillus polymyxa Sx3 isolated from rhizosphere soil of cotton significantly promoted the plant growth and suppressed bacterial leaf blight in rice. Therefore, it could be inferred that P. polymyxa Sx3 has the potential to be used as biocontrol agents in plants grown in different ecological environments.

Abstract P3-06-10: Multiscale modeling of omics data for precision breast cancer treatment

Introduction: The vast majority of cancer patients continue to receive treatments that are minimally informed by omics data. In the case of breast cancer, only ER and HER2 are routinely used for treatment selection. There is a particular need for personalized treatment in individuals with primary and secondary drug resistance or aggressive breast cancers. Emerging bioinformatics and statistical methods have made a fundamental impact on cancer research. However, challenges remains with regard to patient-centric data analysis and providing genomic data guidance to oncologists. There exists a large number of FDA approved anti-neoplastic drugs used to treat cancers other than breast and the development of innovative informatics methods and algorithms to repurpose those drugs should benefit breast cancer patients.

Methods and Results: We have developed precision care systems (such as PANOPLY and CORPUS) to identify personalized therapies for an individual patient and to deliver genomic reports in a standard, searchable format so that a researcher or an oncologist can quickly navigate through molecular data and obtain prioritized drugs and targets.The PANOPLY (Precision cancer genomics report: single sample inventory) algorithm applies machine learning and topology-based network analysis methods to integrate multi-omics profiles and clinical data; individual-specific molecular alterations are identified and compared with a set of matched-controls having similar clinical data. Since there is a lack of a “gold standard” dataset to test such algorithms, we simulated 500 case-control sets and evaluated drug predictions across multiple simulation scenarios. We applied the PANOPLY algorithm to The Cancer Genome Atlas (TCGA) breast cancer cohort, which consists of multi-omics data and clinical data. In addition, PANOPLY was also applied to an in-house neoadjuvant breast cancer study (BEAUTY) that consists of multi-omics data, clinical data, and patient-derived xenografts (PDXs). In the TCGA breast cancer study we obtained survival data to determine the cases and matched-controls; and in the BEAUTY, we used pathologic complete response (pCR) as an outcome to determine responders and non-responders. Recurrent targetable alterations were not enriched in patients without pCR in the BEAUTY study. We have applied the PANOPLY to non-responder patients to identify individual specific alterations, dysregulated networks, drug targets, and drugs for each patient and stored them as case reports in CORPUS (Computational Oncology Reports and Precision therapeUticS), a web-based repository that allows clinicians to review genomic reports. Using comprehensive “omic” data derived from a triple negative breast cancer patient who had pre and post-neoadjuvant chemotherapy PDXs, PANOPLY prioritized the PARP inhibitors as the top class of drug. Using the PDX models available from this patient, we tested olaparib and confirmed the in vivo antitumor activity (more effective than vehicle with a p-value &lt; 0.05 in the PDXs). Further studies to confirm PANOPLY findings are currently underway.

Conclusions: In summary, the PANOPLY and CORPUS systems incorporate molecular data together with clinical data to provide genomic reports with proposed drug targets to advance or enable precision breast cancer care.

Citation Format: Kalari KR, Sinnwell JP, Thompson KJ, Tang X, Carlson EE, Alaparthi T, Yu J, Vedell PT, Kalmbach MT, Bockol MA, Hossain A, Weinshilboum RM, Boughey JC, Wang L, Suman VJ, Goetz MP. Multiscale modeling of omics data for precision breast cancer treatment [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-06-10.

Role of selenium addition to CdZnTe matrix for room-temperature radiation detector applications

Because of its ideal band gap, high density and high electron mobility-lifetime product, cadmium zinc telluride (CdZnTe or CZT) is currently the best room-temperature compound-semiconductor X- and gamma-ray detector material. However, because of its innate poor thermo-physical properties and above unity segregation coefficient for Zn, the wide spread deployment of this material in large-volume CZT detectors is still limited by the high production cost. The underlying reason for the low yield of high-quality material is that CZT suffers from three major detrimental defects: compositional inhomogeneity, high concentrations of dislocation walls/sub-grain boundary networks and high concentrations of Te inclusions/precipitates. To mitigate all these disadvantages, we report for the first time the effects of the addition of selenium to the CZT matrix. The addition of Se was found to be very effective in arresting the formation of sub-grain boundaries and its networks, significantly reducing Zn segregation, improving compositional homogeneity and resulting in much lower concentrations of Te inclusions/precipitates. Growth of the new quaternary crystal Cd_1−xZn_xTe_1−ySe_y (CZTS) by the Traveling Heater Method (THM) is reported in this paper. We have demonstrated the production of much higher yield according to its compositional homogeneity, with substantially lower sub-grain boundaries and their network, and a lower concentration of Te inclusions/precipitates.

Pattern of Casualties Attending in the Casualty Department of Mymensingh Medical College Hospital, Mymensingh, Bangladesh

Casualty, in relation to personnel, any person who is lost to his organization; by reason of being declared dead, wounded, diseased, detained, captured or missing. Casualty service or department is not well organized in the hospitals of our country. We have recently started functioning casualty department to manage casualties properly in spite of the increasing workload and emerging needs of this department. This study was conducted in the Casualty department, Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh to analyze the number of patients and pattern of casualties. A total number of 17435 patients were enrolled in this retrospective observational study. Data was collected from hospital records of all patients attending in the Casualty Department, MMCH between November 19, 2017 and May 18, 2018 and patients were categorized on the basis of their mode of injury. The demographic characteristics of patients with mode of Casualty were analyzed. Male were 75% and female 25%. Avergae per day patient attended in the Casualty department was 96, maximum was 176 and minimum 33. According to age sub-division, 11-20 years age group attended maxiumum was 48. One day attended Road traffic accident (RTA) maximum was 65 and minimum was 3, Non-RTA maximum was 83 and minimum 25, physical assaults maximum was 48 and minimum 1. Injury due to fall and RTA were the common mode of casualty especially in the young population in the study area. Study showed that injury caused by fall was 44% among the all patients. Patients due to fall from tree was highest (35%) in April-May. Incidents of fall were followed by RTA which was 25%. Physical assaults (17%), machinery injury (9%) and others were 5%.

In vitro cytotoxicity and antibiotic application of green route surface modified ferromagnetic TiO2 nanoparticles

The enormous numbers of applications of TiO₂ nanoparticles (NPs) cause concern about their risk to the environment and human health. Consequently, motivated by the necessity of searching for new sources of TiO₂ NPs of low cytotoxicity with antibacterial activity, we synthesized TiO₂ NPs by a green route using a solution of titanium(iv) isopropoxide as a precursor and an aqueous extract of Artocarpus heterophyllus leaf as a reducing and surface modifying agent. We investigated their structure, shape, size, and magnetic properties, and evaluated their antibiotic application and cytotoxicity. The synthesized TiO₂ NPs were applied against two Gram-negative bacteria (E. coli and S. typhimurium) and two Gram-positive bacteria (S. aureus and B. subtilis) to observe their antibacterial activity; and eventually clear zones of inhibition formed by the TiO₂ NPs were obtained. Moreover, after exposing the synthesized TiO₂ NPs to HeLa cells (carcinoma cells) and Vero cells (normal cells), no toxic effect was found up to a dose of 1000 mg L⁻¹, indicating the safe use of the samples up to at least 1000 mg L⁻¹. However, toxic effects on HeLa cells and Vero cells were observed at doses of 2000 mg L⁻¹ and 3000 mg L⁻¹, respectively. These results indicate the safe use of Artocarpus heterophyllus leaf extract mediated synthesized TiO₂ NPs in their potential applications.

Artocarpus heterophyllus leaf extract mediated green synthesized TiO₂ nanoparticles exhibit less toxicity with high antibacterial activity.

Investigation of methicillin-resistant Staphylococcus aureus among clinical isolates from humans and animals by culture methods and multiplex PCR

Background

Staphylococcus aureus is responsible for large numbers of hospital-related and community-acquired infections. In this study, we investigated the presence of S. aureus and methicillin-resistant S. aureus (MRSA) in 100 samples from animals (55 cattle, 36 dogs, and 9 cats) and 150 samples from hospitalized human patients. The samples were collected from healthy and diseased animals and from diseased humans and included milk, wound swab, pus, exudates, nasal swab and diabetic ulcer. Initially, S. aureus was isolated and identified by colony morphology, Gram staining, and biochemical tests (catalase and coagulase tests). The S. aureus-positive samples were examined by polymerase chain reaction (PCR) to determine their MRSA status.

Results

Of the 100 animal samples, 29 were positive for S. aureus. Four samples (13.8%) from dogs were MRSA-positive, but samples from cattle and cats were MRSA-negative. Of the 150 human samples we collected, 64 were S. aureus-positive and, of these, 34 (53.1%) were MRSA-positive. Most (28%) of the MRSA samples were isolated from surgical wound swabs, followed by the pus from skin infections (11%), exudates from diabetic ulcers (6%), exudates from burns (4%), and aural swabs (3%). By contrast, a low MRSA detection rate (n = 4) was seen in the non-human isolates, where all MRSA bacteria were isolated from nasal swabs from dogs. The antimicrobials susceptibility testing results showed that S. aureus isolates with mecA genes showed resistance to penicillin (100%), oxacillin (100%), erythromycin (73.5%), ciprofloxacin (70.6%), and gentamicin (67.7%). The lowest resistance was found against ceftazidime, and no vancomycin-resistant isolates were obtained.

Conclusions

We detected S. aureus and MRSA in both human and canine specimens. Isolates were found to be resistant to some of the antimicrobials available locally. MRSA carriage in humans and animals appears to be a great threat to effective antimicrobials treatment. The prudent use of antimicrobials will reduce the antimicrobial resistance. Our findings will help to find the most appropriate treatment and to reduce antimicrobial resistance in the future by implementing prudent use of antimicrobials. Further studies are required to better understand the epidemiology of MRSA human–animal inter-species transmission in Bangladesh.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1611-0) contains supplementary material, which is available to authorized users.

Halotolerant bacteria belonging to operational group Bacillus amyloliquefaciens in biocontrol of the rice brown stripe pathogen Acidovorax oryzae

AIMS

The aim of this study was to evaluate the antagonistic activity of halotolerant bacteria against rice brown stripe pathogen Acidovorax oryzae.

METHODS AND RESULTS

Fifteen of 136 isolates of halotolerant bacteria exhibited strong in vitro and in vivo antagonistic activity against both strains of A. oryzae. The 15 antagonistic isolates were identified as 'operational group Bacillus amyloliquefaciens' based on physiological and biochemical features, fatty acid profiles as well as sequence analysis of 16S rRNA, gyrA and rpoB genes. Furthermore, this result indicated that the most effective antagonistic isolates K5-3 and PPB6 could produce siderophore in iron-limiting medium, and four kinds of secondary metabolites based on MALDI-TOF analysis. In addition, the culture filtrates of isolates K5-3 and PPB6 caused the damage of cell membrane evidenced by the TEM images, and resulted in 73-80% reduction in cell numbers, 55-65% reduction in biofilm formation, and 42-50% reduction in swimming ability of both strains of A. oryzae.

CONCLUSIONS

These isolates in particular K5-3 and PPB6 of halotolerant bacteria markedly inhibited the growth of A. oryzae.

SIGNIFICANCE AND IMPACT OF THE STUDY

To our knowledge, this is the first report on biological control of halotolerant bacteria against bacterial brown stripe of rice.

Ethnic variation in personality disorder: evaluation of 6 years of hospital admissions

Aims and methodThere is limited evidence on ethnic differences in personality disorder prevalence rates. We compared rates of people with personality disorder admitted to hospital in East London from 2007 to 2013.

RESULTS

Of all people admitted to hospital, 9.7% had a personality disorder diagnosis. The admission rate for personality disorder has increased each year. Compared with White subjects, personality disorder was significantly less prevalent among Black and other minority ethnic (BME) groups. Personality disorder was diagnosed in 20% of forensic, 11% of general adult, 8% of adolescent and 2% of old-age in-patients.Clinical implicationsThe increasing number of personality disorder diagnoses year on year indicates the increasing impact of personality disorder on in-patient services. It is important to identify and appropriately manage patients with a personality disorder diagnosis due to the significant strain they place on resources. The reasons for fewer admissions of BME patients may reflect alternative service use, a truly lower prevalence rate or under-detection.Declaration of interestNone.

Can Bangladesh produce enough cereals to meet future demand?

Bangladesh faces huge challenges in achieving food security due to its high population, diet changes, and limited room for expanding cropland and cropping intensity. The objective of this study is to assess the degree to which Bangladesh can be self-sufficient in terms of domestic maize, rice and wheat production by the years 2030 and 2050 by closing the existing gap (Yg) between yield potential (Yp) and actual farm yield (Ya), accounting for possible changes in cropland area. Yield potential and yield gaps were calculated for the three crops using well-validated crop models and site-specific weather, management and soil data, and upscaled to the whole country. We assessed potential grain production in the years 2030 and 2050 for six land use change scenarios (general decrease in arable land; declining ground water tables in the north; cropping of fallow areas in the south; effect of sea level rise; increased cropping intensity; and larger share of cash crops) and three levels of Yg closure (1: no yield increase; 2: Yg closure at a level equivalent to 50% (50% Yg closure); 3: Yg closure to a level of 85% of Yp (irrigated crops) and 80% of water-limited yield potential or Yw (rainfed crops) (full Yg closure)). In addition, changes in demand with low and high population growth rates, and substitution of rice by maize in future diets were also examined. Total aggregated demand of the three cereals (in milled rice equivalents) in 2030 and 2050, based on the UN median population variant, is projected to be 21 and 24% higher than in 2010. Current Yg represent 50% (irrigated rice), 48-63% (rainfed rice), 49% (irrigated wheat), 40% (rainfed wheat), 46% (irrigated maize), and 44% (rainfed maize) of their Yp or Yw. With 50% Yg closure and for various land use changes, self-sufficiency ratio will be > 1 for rice in 2030 and about one in 2050 but well below one for maize and wheat in both 2030 and 2050. With full Yg closure, self-sufficiency ratios will be well above one for rice and all three cereals jointly but below one for maize and wheat for all scenarios, except for the scenario with drastic decrease in boro rice area to allow for area expansion for cash crops. Full Yg closure of all cereals is needed to compensate for area decreases and demand increases, and then even some maize and large amounts of wheat imports will be required to satisfy demand in future. The results of this analysis have important implications for Bangladesh and other countries with high population growth rate, shrinking arable land due to rapid urbanization, and highly vulnerable to climate change.

Green synthesis of bio-molecule encapsulated magnetic silver nanoparticles and their antibacterial activity

Persuaded by the necessity of finding new sources of antibiotics, silver nanoparticles (Ag NPs) were synthesized by adopting a newly developed green synthesis technique and subsequently, their antibacterial activity against different pathogenic bacteria was evaluated. We have successfully synthesized bio-molecule capped ferromagnetic Ag NPs with an average crystallite size of 13 nm using AgNO₃ solution as a precursor and Artocarpus heterophyllus leaf extract as a reducing and capping agent. The characterization of the synthesized Ag NPs was carried out using various techniques such as UV-visible (UV-Vis) spectroscopy, energy dispersive X-ray (EDX) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermogravimetry (TG), and vibrating sample magnetometer (VSM) analyses. After exposing the synthesized Ag NPs to two Gram-positive bacteria – Staphylococcus aureus and Bacillus cereus and two Gram-negative bacteria – Escherichia coli and Salmonella typhimurium, the zones of inhibition were found to be 15, 16, 19, and 18 mm, respectively. These results imply that the Artocarpus heterophyllus leaf extract mediated green synthesized bio-molecules encapsulated Ag NPs can be considered as a potential antibiotic against human pathogens which is very encouraging.

Persuaded by the necessity of finding new sources of antibiotics, Ag NPs were synthesized by adopting a newly developed green synthesis technique and subsequently, their antibacterial activity against different pathogenic bacteria was evaluated.

Anthropogenic shift of planktonic food web structure in a coastal lagoon by freshwater flow regulation

Anthropogenic modification of aquatic systems has diverse impacts on food web interactions and ecosystem states. To reverse the adverse effects of modified freshwater flow, adequate management of discharge is required, especially due to higher water requirements and abstractions for human use. Here, we look at the effects of anthropogenically controlled freshwater flow regimes on the planktonic food web of a Ramsar listed coastal lagoon that is under recovery from degradation. Our results show shifts in water quality and plankton community interactions associated to changes in water flow. These shifts in food web interactions represent modifications in habitat complexity and water quality. At high flow, phytoplankton-zooplankton interactions dominate the food web. Conversely, at low flow, bacteria, viruses and nano/picoplankton interactions are more dominant, with a substantial switch of the food web towards heterotrophy. This switch can be associated with excess organic matter loading, decomposition of dead organisms, and synergistic and antagonistic interactions. We suggest that a lower variability in flow amplitude could be beneficial for the long-term sustaining of water quality and food web interactions, while improving the ecosystem health of systems facing similar stresses as the Coorong.

Abstract OT2-01-07: A phase 2 study of abemaciclib plus pembrolizumab for patients with hormone receptor positive (HR+), HER2 negative (HER2-) metastatic breast cancer (MBC)

Background:

Abemaciclib is a small molecule inhibitor of both cyclin-dependent kinase (CDK) 4 and CDK6 administered orally twice daily on a continuous schedule. In I3Y-MC-JPBA, a phase I study, abemaciclib demonstrated acceptable safety, tolerability, and single-agent activity as monotherapy in different tumor types, including HR+ MBC (Patnaik A,et al. Cancer Discov 2016;6:1–14). In MONARCH 1, a phase 2 study, abemaciclib demonstrated a 19.7% objective response rate (ORR) with a median duration of response (DoR) of 8.6 months, median progression-free survival (PFS) of 6.0 months, and clinical benefit rate (CBR) of 42.4% in patients with HR+, HER2- MBC whose disease progressed on or after endocrine therapy and chemotherapy (Dickler, M. et al. American Society of Clinical Oncology (ASCO), abstract #510 (2016).). Pembrolizumab is a humanized monoclonal antibody against the programmed death receptor-1 (PD-1) protein that has shown preliminary efficacy in single-arm monotherapy trials in ER+/HER2- advanced breast cancer.

Trial design:

This open-label, phase 2 study will evaluate the safety and preliminary efficacy of abemaciclib 150 mg given orally every 12 hours on days 1-21 of a 21-day cycle in combination with intravenous pembrolizumab 200 mg on day 1 of a 21-day cycle in approximately 75 patients with stage IV non-small cell lung cancer or HR+, HER2- MBC (ClinicalTrials.gov NCT02779751). The study will include 3 disease-specific cohorts, each with approximately 25 patients. Only the HR+, HER2- MBC cohort will be presented here.

Eligibility criteria:

Eligible patients for the MBC cohort include women with confirmed HR+, HER2- MBC who have completed at least 1 but no more than 2 prior chemotherapy regimens in the metastatic setting; will provide tumor tissue prior to and after treatment (cycle 3, day 1); have measurable disease (RECIST v.1.1), adequate organ function, an ECOG performance status ≤1, and a life expectancy ≥12 weeks; are ≥18 yrs of age and able to swallow oral medications; and have not received treatment with any CDK 4 and 6 inhibitors or PD-1 or PD-L1 inhibitors.

Specific aims:

The primary objective is to characterize the safety profile of the combination of abemaciclib and pembrolizumab. Key secondary objectives include ORR, DoR, disease control rate (DCR), PFS, overall survival (OS), and characterization of pharmacokinetics.

Statistical methods:

The safety population includes patients who received at least one dose of study drug. ORR, DoR, DCR, and PFS analyses will be evaluated according to RECIST v.1.1 and irRECIST for disease progression. Time-to-event variables, such as DoR, PFS, and OS, will be estimated by Kaplan-Meier methodology. An interim analysis of safety and preliminary efficacy may occur for each cohort after all patients have completed (or discontinued from) approximately 24 weeks of treatment. The final analysis of OS will occur based on data collected for approximately 12 months after the last patient receives treatment.

Target accrual:

Approximately 75 patients are planned for the trial; 25 patients will comprise the MBC cohort.

Contact information: 1-877-CTLILLY (1-877-285-4559).

Citation Format: Rugo H, Tolaney S, Dickler M, Kabos P, Ho C-L, Wildiers H, Jerusalem G, Alés-Martínez JE, Hossain A, Johnston E, Gianni L. A phase 2 study of abemaciclib plus pembrolizumab for patients with hormone receptor positive (HR+), HER2 negative (HER2-) metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-07.

Comparative genomics reveals high biological diversity and specific adaptations in the industrially and medically important fungal genus Aspergillus

BACKGROUND

The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of food, and an important genetic model. The genome sequences of eight aspergilli have already been explored to investigate aspects of fungal biology, raising questions about evolution and specialization within this genus.

RESULTS

We have generated genome sequences for ten novel, highly diverse Aspergillus species and compared these in detail to sister and more distant genera. Comparative studies of key aspects of fungal biology, including primary and secondary metabolism, stress response, biomass degradation, and signal transduction, revealed both conservation and diversity among the species. Observed genomic differences were validated with experimental studies. This revealed several highlights, such as the potential for sex in asexual species, organic acid production genes being a key feature of black aspergilli, alternative approaches for degrading plant biomass, and indications for the genetic basis of stress response. A genome-wide phylogenetic analysis demonstrated in detail the relationship of the newly genome sequenced species with other aspergilli.

CONCLUSIONS

Many aspects of biological differences between fungal species cannot be explained by current knowledge obtained from genome sequences. The comparative genomics and experimental study, presented here, allows for the first time a genus-wide view of the biological diversity of the aspergilli and in many, but not all, cases linked genome differences to phenotype. Insights gained could be exploited for biotechnological and medical applications of fungi.

Test of a 32-channel Prototype ASIC for Photon Counting Application

A new low-power application-specific integrated circuit (ASIC) for Cadmium Zinc Telluride (CZT) detectors for single-photon emission computed tomography (SPECT) application is being developed at BNL. As the first step, a 32-channel prototype ASIC was designed and tested recently. Each channel has a preamplifier followed by CR-RC³ shaping circuits and three independent energy bins with comparators and 16-bit counters. The ASIC was fabricated with TSMC 0.35-μm complementary metal-oxide-semiconductor (CMOS) process and tested in laboratories. The power consumption is around 1 mW/ch with a 2.5-V supply. With a gain of 400 mV/fC and the peaking time of 500 ns, the equivalent noise charge (ENC) of 360 e- has been measured in room temperature while the crosstalk rate is less than 0.3%. The 10-bit DACs for global thresholds have an integral nonlinearity (INL) less than 0.56% and differential nonlinearity (DNL) less than 0.33%. In the presentation, we will report the detailed test results with this ASIC.

Novel ZnO:Al contacts to CdZnTe for X- and gamma-ray detectors

CdZnTe (CZT) has made a significant impact as a material for room-temperature nuclear-radiation detectors due to its potential impact in applications related to nonproliferation, homeland security, medical imaging, and gamma-ray telescopes. In all such applications, common metals, such as gold, platinum and indium, have been used as electrodes for fabricating the detectors. Because of the large mismatch in the thermal-expansion coefficient between the metal contacts and CZT, the contacts can undergo stress and mechanical degradation, which is the main cause for device instability over the long term. Here, we report for the first time on our use of Al-doped ZnO as the preferred electrode for such detectors. The material was selected because of its better contact properties compared to those of the metals commonly used today. Comparisons were conducted for the detector properties using different contacts, and improvements in the performances of ZnO:Al-coated detectors are described in this paper. These studies show that Al:ZnO contacts to CZT radiation detectors offer the potential of becoming a transformative replacement for the common metallic contacts due to the dramatic improvements in the performance of detectors and improved long-term stability.

Stability of the Baseline Holder in Readout Circuits For Radiation Detectors

Baseline holder (BLH) circuits are used widely to stabilize the analog output of application-specific integrated circuits (ASICs) for high-count-rate applications. The careful design of BLH circuits is vital to the overall stability of the analog-signal-processing chain in ASICs. Recently, we observed self-triggered fluctuations in an ASIC in which the shaping circuits have a BLH circuit in the feedback loop. In fact, further investigations showed that methods of enhancing small-signal stabilities cause an even worse situation. To resolve this problem, we used large-signal analyses to study the circuit's stability. We found that a relatively small gain for the error amplifier and a small current in the non-linear stage of the BLH are required to enhance stability in large-signal analysis, which will compromise the properties of the BLH. These findings were verified by SPICE simulations. In this paper, we present our detailed analysis of the BLH circuits, and propose an improved version of them that have only minimal self-triggered fluctuations. We summarize the design considerations both for the stability and the properties of the BLH circuits.

Anti-tuberculosis drug resistance in Bangladesh: reflections from the first nationwide survey

OBJECTIVE

To determine the prevalence of tuberculosis (TB) drug resistance in Bangladesh.

DESIGN

Weighted cluster sampling among smear-positive cases, and standard culture and drug susceptibility testing on solid medium were used.

RESULTS

Of 1480 patients enrolled during 2011, 12 falsified multidrug-resistant TB (MDR-TB) patients were excluded. Analysis included 1340 cases (90.5% of those enrolled) with valid results and known treatment antecedents. Of 1049 new cases, 12.3% (95%CI 9.3-16.1) had strains resistant to any of the first-line drugs tested, and 1.4% (95%CI 0.7-2.5) were MDR-TB. Among the 291 previously treated cases, this was respectively 43.2% (95%CI 37.1-49.5) and 28.5% (95%CI 23.5-34.1). History of previous anti-tuberculosis treatment was the only predictive factor for first-line drug resistance (OR 34.9). Among the MDR-TB patients, 19.2% (95%CI 11.3-30.5; exclusively previously treated) also showed resistance to ofloxacin. Resistance to kanamycin was not detected.

CONCLUSION

Although MDR-TB prevalence was relatively low, transmission of MDR-TB may be increasing in Bangladesh. MDR-TB with fluoroquinolone resistance is rapidly rising. Integrating the private sector should be made high priority given the excessive proportion of MDR-TB retreatment cases in large cities. TB control programmes and donors should avoid applying undue pressure towards meeting global targets, which can lead to corruption of data even in national surveys.

An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras

We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm(3) detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays' performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

Role of crush smear cytology in the diagnosis of gastrointestinal malignancy

Crush smear cytology, commonly used for central nervous system lesions was reported to be useful in the diagnosis of GI malignancies. This study was designed to see the accuracy of crush smear cytology in detection of gastrointestinal malignancy in relation to histopathological examination. First 4 or 5 bits of pinch biopsy specimens from each of the consecutive patients having endoscopic findings suggestive of carcinoma of gastro-intestinal tract were examined by conventional paraffin embedding and H-E staining by a cytologist. Crush smears stained with Papanicolaou's stain were prepared with the last bit of specimen and were examined by another cytologist. The diagnostic accuracy was examined by correlating with clinical and histological data. Out of 100 cases of suspected oesophageal malignancies, 99 were diagnosed as carcinoma by histopathology and 84 (sensitivity 83.83%, accuracy 83%, K - 0.14) cases were positive for malignancy by crush smear cytology. Out of 60 cases of gastric lesion, 54 and 44 cases were proved to be malignant by histopathology (sensitivity 76%, accuracy 73.3%, K - 0.2) and crush smear cytology respectively. Fifty four of the 57 cases of colonic lesions were proved to be malignant by histopathology and 50 (sensitivity 91%, accuracy 89.5%, K - 0.34) were malignant by crush smear cytology. Combining two methods the accuracy was 100%, 95% and 96.5% in detecting oesophageal, gastric and colonic malignancies respectively. Concordance rate of both the methods in diagnosing oesophageal, gastric and colonic lesions were 883.83%, 73.3% and 89.5% respectively. Crush smear cytology is a cheap, easy and rapidly performing technique. The diagnostic yield is very high when the technique is combined with histopathology. It may be used as a useful adjunct to conventional histopathology.

Endodontic management of symptomatic pulpal pathosis by single -visit root canal therapy

Single-visit root canal therapy is one of the reality in modern endodontics globally, both for vital and non-vital teeth, despite many research efforts and much controversy, specially when post-operative pain is concerned. There are increased post-operative complications as pain, swelling, discomfort in managing teeth having symptomatic pulpal pathosis. To clinically verify the possibility to treat symptomatic vital and non-vital teeth in one visit technique, 126 patiens were selected and advised to undergone single visit endodontic treatment at the Department of Conservative Dentistry and Endodontics, Bangabandhu Sheikh Mujib Medical University, Dhaka. Endodontically involved symptomatic vital and symptomatic non-vital teeth were enrolled in two groups and advised to undergone single visit endodontic treatment. Both groups were assessed at 24 hours, 48 hours, 72 hours and long term post operative evaluation up to 10 months. The main outcome measure was post operative pain. The result of our study indicates that single visit root canal treatment is a safe, effective and practical method of treatment of an endodontically involved tooth both in vital and non vital cases when applied in appropriate situation. Significantly fewer patients of symptomatic vital cases reported pain in immediate follow up i.e. 24 hours, 48 hours and 72 hours in comparison to non vital cases (12.69% vs. 22.2%, 4.16% vs. 11.11%, 1.58% vs. 7.93%). At 10 months of long term follow up the recall rate was 74.35% and 90(71%) of patients were comfortable after receiving treatment. Post operative pain incidence in single visit was equivalent to that of multi visit endodontics, provided one had an accurate diagnosis, proper case selection and skilled technique.

Ultrasonographic evaluation of breast mass

Breast cancer is the second most common cause of cancer-related mortality among women. The aim of the present study is to investigate the diagnostic accuracy of ultrasonography in correlation with histopathology in suspected patients of breast mass. In this cross-sectional study, ultrasonography and histopathology was done on 50 clinically suspected patients of breast mass in the Department of Radiology and Imaging Mymensingh Medical College Hospital, Mymensingh from 1st April 2008 to 30th March 2009 for the period of one year. Women of all ages were included in the study. Findings of USG and histopathology were correlated. In diagnosis of malignant mass by USG, 32(64%) of cases were diagnosed as malignant and 18(36%) cases as other than malignant. Here 31(86.1%) of sonographically diagnosed malignant lesions were also proved as malignant lesion by histopathologically and 1(7.1%) other than malignant. Out of 18 sonographically diagnosed cases of other than malignant lesions 13(92.9%) were proved histopathologically and 5(13.9%) did not match with sonographic findings as other than normal. USG, in diagnosis of malignant lesion, sensitivity was 86.1%, specificity 92.9%, positive predictive value (PPV) (96.6%), negative predictive value 72.2% and accuracy was 88.0% and comparable to other study. In the conclusion this study permits to conclude that ultrasonography has significant sensitivity, specificity, accuracy, positive predictive value and negative predictive value in the diagnosis of both benign and malignant breast mass.

Ultrasound guided fine needle aspiration cytology: a sensitive diagnostic tool for diagnosis of intra-abdominal lesions

Ultrasound guided fine needle aspiration cytology is widely accepted as a safe diagnostic procedure in various neoplastic and non-plastic disorders. This study was conducted to determine the usefulness and diagnostic accuracy of ultrasound guided fine needle aspiration cytology in the diagnosis of intraabdominal lesions. This cross sectional study was conducted in the Department of Radiology and Imaging, Sylhet MAG Osmani Medical College Hospital, Sylhet, Bangladesh during the period of June 2007 to June 2009. A total 78 patients with intra abdominal lesions were included in this study. Fifty nine (75.6%) were males and 19 (24.4%) were females. Out of total aspirates 29 (37.2%) were categorized as benign, 41 (52.6%) were malignant and 8 (10.3%) were non-representative, as it contained only blood. Most of the benign lesions were liver abscess 19 (24.4%). A diagnosis of primary malignancy was established in 26 (33.3%) and that of secondary in 15 (19.2%). The results showed a sensitivity of 89.7%. Ultrasound guided fine needle aspiration cytology is a sensitive diagnostic tool in a wide spectrum of intra-abdominal neoplastic and non-neoplastic disorders. It is a simple, safe, rapidand inexpensive technique.