AcumenTM hypotension prediction index guidance for prevention and treatment of hypotension in noncardiac surgery: a prospective, single-arm, multicenter trial

BACKGROUND

Intraoperative hypotension is common during noncardiac surgery and is associated with postoperative myocardial infarction, acute kidney injury, stroke, and severe infection. The Hypotension Prediction Index software is an algorithm based on arterial waveform analysis that alerts clinicians of the patient's likelihood of experiencing a future hypotensive event, defined as mean arterial pressure < 65 mmHg for at least 1 min.

METHODS

Two analyses included (1) a prospective, single-arm trial, with continuous blood pressure measurements from study monitors, compared to a historical comparison cohort. (2) A post hoc analysis of a subset of trial participants versus a propensity score-weighted contemporaneous comparison group, using external data from the Multicenter Perioperative Outcomes Group (MPOG). The trial included 485 subjects in 11 sites; 406 were in the final effectiveness analysis. The post hoc analysis included 457 trial participants and 15,796 comparison patients. Patients were eligible if aged 18 years or older, American Society of Anesthesiologists (ASA) physical status 3 or 4, and scheduled for moderate- to high-risk noncardiac surgery expected to last at least 3 h.

MEASUREMENTS

minutes of mean arterial pressure (MAP) below 65 mmHg and area under MAP < 65 mmHg.

RESULTS

Analysis 1: Trial subjects (n = 406) experienced a mean of 9 ± 13 min of MAP below 65 mmHg, compared with the MPOG historical control mean of 25 ± 41 min, a 65% reduction (p < 0.001). Subjects with at least one episode of hypotension (n = 293) had a mean of 12 ± 14 min of MAP below 65 mmHg compared with the MPOG historical control mean of 28 ± 43 min, a 58% reduction (p< 0.001). Analysis 2: In the post hoc inverse probability treatment weighting model, patients in the trial demonstrated a 35% reduction in minutes of hypotension compared to a contemporaneous comparison group [exponentiated coefficient: - 0.35 (95%CI - 0.43, - 0.27); p < 0.001].

CONCLUSIONS

The use of prediction software for blood pressure management was associated with a clinically meaningful reduction in the duration of intraoperative hypotension. Further studies must investigate whether predictive algorithms to prevent hypotension can reduce adverse outcomes.

TRIAL REGISTRATION

Clinical trial number: NCT03805217. Registry URL: https://clinicaltrials.gov/ct2/show/NCT03805217 . Principal investigator: Xiaodong Bao, MD, PhD. Date of registration: January 15, 2019.

Multicenter evaluation of the Quantra with the QStat Cartridge in adult patients undergoing liver transplantation

Blood loss and transfusion of blood products are key concerns during liver transplantation. Whole-blood viscoelastic testing devices have been used to monitor hemostatic function and guide the transfusion of blood products in this patient population. The Quantra System with the QStat Cartridge is a new point-of-care, closed-system viscoelastic testing device that measures changes in clot stiffness during coagulation and fibrinolysis using ultrasound detection of resonance. The aim of this multicenter prospective observational study was to evaluate the Quantra System against the ROTEM delta device in monitoring coagulation and fibrinolysis in patients undergoing liver transplantation. One hundred twenty-five (125) adult subjects (above 18 y old) were enrolled across 5 medical centers in the US. Blood samples were collected at a minimum of 3-time points: preincision (baseline), during the anhepatic phase, and after the start of reperfusion. Performance was assessed as the correlation of equivalent measurements from the QStat Cartridge and ROTEM delta INTEM, EXTEM, and FIBTEM assays. In addition, a clinical concordance analysis was performed to assess the agreement between the 2 devices related to the detection of fibrinolysis. The correlation between the 2 viscoelastic testing devices was strong, with r -values ranging between 0.88 and 0.95, and the overall agreement with respect to detecting fibrinolysis was 90.3% (CI, 86.9%-93.2%). The results indicate that the Quantra with the QStat Cartridge provides comparable information as the ROTEM delta in the assessment of hemostatic function during a liver transplant. Quantra's simplicity of use and availability of rapid results may provide clinicians with a faster, more convenient means to assess coagulation and fibrinolysis status in the operating room and critical care setting.

The Effect of Stereotactic Body Radiotherapy (SBRT) Dose-Fraction (fx) Schema on Non-Small Cell Lung Cancer (NSCLC)

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) dose-fraction (fx) schema for non-small cell lung cancer (NSCLC) varies at different centers and commonly involves 3 to 5 fx. Additionally, the frequency of treatment per week, or treatment schedules (TS), can also differ. We sought to evaluate and compare the effect of different dose-fx schemas on overall survival (OS).

MATERIALS/METHODS

We retrieved data from the National Cancer Database. Patient eligibility included early-stage NSCLC with cT1-2 N0M0 disease treated with SBRT using 3-5f x regimens. Demographics and clinical characteristics were identified. Biologically effective dose (BED) and total dose (TD) were calculated. TD included following: 45-60 Gy for 3 fx, 48-60 Gy for 4 fx, and 50-60 Gy for 5 fx. TS was classified as one of the following: daily, every other day, twice per week, or prolonged (less frequently than twice weekly). Non-prolonged TS was defined as daily, every other day, and twice per week. OS was calculated from the date of end of RT to the date of death and censored at the date of last contact. Kaplan Meier method was used to estimate OS and log-rank tests were used to compare the difference between groups. TS was compared pairwise within each individual fx-group. Univariable Cox proportional models with robust standard errors to account for within institution correlations were used to investigate the association between BED, TD, TS, fx-group and OS. Within each fx-group, BED was also assessed and compared.

RESULTS

A total of 3244 patients were identified, with median age 73. 48% were males and 52% females. 601 (19%) patients received 3 fx, 884 (27%) received 4 fx, and 1759 (54%) received 5 fx treatments. For the overall cohort, median and mean BEDs were 112 and 119, respectively. TS did not show a difference in OS among each individual fx group. Overall, prolonged vs non-prolonged schedules also did not show a difference in OS (p = 0.64). OS was superior in the 3 fx group compared to 4 and 5 fx groups, with median survival times of 61.5 vs 53.7 vs 52.6 months, respectively (p = 0.046). Overall, an increase in BED reduced risk of death (HR = 0.97 per 10-units, CI: 0.94-0.99, p = 0.04). When stratified by fx, each 10 unit rise in BED for those treated with 5 fx reduced the risk of death by 8% (HR = 0.92, CI: 0.87-0.97, p<0.01). However, increasing BED was not associated with change in OS for 3 fx (HR = 1.00, CI: 0.93-1.08, p = 0.93) and 4 fx (HR = 1.08, p = 0.08) regimens. Patients who received BED greater than the median (BED>112) had improved OS compared to those receiving BED£112 (HR = 0.86, p = 0.047). When evaluating the 5 fx-group individually, BED >100 (median of 5fx group) had superior OS compared to £100 (HR = 0.80, p = 0.02).

CONCLUSION

Three-fraction regimens have superior OS compared to 4 and 5 fx regimens. Higher BED improves OS in 5 fx regimens. Treatment schedule variations among individual fx-groups does not impact OS.

Positron emission tomography myocardial perfusion imaging (PET MPI) findings predictive of post-liver transplant major adverse cardiac events

Positron emission tomography myocardial perfusion imaging (PET MPI) is a noninvasive diagnostic test capable of detecting coronary artery disease, structural heart disease, and myocardial flow reserve (MFR). We aimed to determine the prognostic utility of PET MPI to predict post-liver transplant (LT) major adverse cardiac events (MACE). Among the 215 LT candidates that completed PET MPI between 2015 and 2020, 84 underwent LT and had 4 biomarker variables of clinical interest on pre-LT PET MPI (summed stress and difference scores, resting left ventricular ejection fraction, global MFR). Post-LT MACE were defined as acute coronary syndrome, heart failure, sustained arrhythmia, or cardiac arrest within the first 12 months post-LT. Cox regression models were constructed to determine associations between PET MPI variable/s and post-LT MACE. The median LT recipient age was 58 years, 71% were male, 49% had NAFLD, 63% reported prior smoking, 51% had hypertension, and 38% had diabetes mellitus. A total of 20 MACE occurred in 16 patients (19%) at a median of 61.5 days post-LT. One-year survival of MACE patients was significantly lower than those without MACE (54% vs. 98%, p =0.001). On multivariate analysis, reduced global MFR ≤1.38 was associated with a higher risk of MACE [HR=3.42 (1.23-9.47), p =0.019], and every % reduction in left ventricular ejection fraction was associated with an 8.6% higher risk of MACE [HR=0.92 (0.86-0.98), p =0.012]. Nearly 20% of LT recipients experienced MACE within the first 12 months of LT. Reduced global MFR and reduced resting left ventricular ejection fraction on PET MPI among LT candidates were associated with increased risk of post-LT MACE. Awareness of these PET-MPI parameters may help improve cardiac risk stratification of LT candidates if confirmed in future studies.

Feasibility pilot trial for the Trajectories of Recovery after Intravenous propofol versus inhaled VolatilE anesthesia (THRIVE) pragmatic randomised controlled trial

INTRODUCTION

Millions of patients receive general anaesthesia for surgery annually. Crucial gaps in evidence exist regarding which technique, propofol total intravenous anaesthesia (TIVA) or inhaled volatile anaesthesia (INVA), yields superior patient experience, safety and outcomes. The aim of this pilot study is to assess the feasibility of conducting a large comparative effectiveness trial assessing patient experiences and outcomes after receiving propofol TIVA or INVA.

METHODS AND ANALYSIS

This protocol was cocreated by a diverse team, including patient partners with personal experience of TIVA or INVA. The design is a 300-patient, two-centre, randomised, feasibility pilot trial. Patients 18 years of age or older, undergoing elective non-cardiac surgery requiring general anaesthesia with a tracheal tube or laryngeal mask airway will be eligible. Patients will be randomised 1:1 to propofol TIVA or INVA, stratified by centre and procedural complexity. The feasibility endpoints include: (1) proportion of patients approached who agree to participate; (2) proportion of patients who receive their assigned randomised treatment; (3) completeness of outcomes data collection and (4) feasibility of data management procedures. Proportions and 95% CIs will be calculated to assess whether prespecified thresholds are met for the feasibility parameters. If the lower bounds of the 95% CI are above the thresholds of 10% for the proportion of patients agreeing to participate among those approached and 80% for compliance with treatment allocation for each randomised treatment group, this will suggest that our planned pragmatic 12 500-patient comparative effectiveness trial can likely be conducted successfully. Other feasibility outcomes and adverse events will be described.

ETHICS AND DISSEMINATION

This study is approved by the ethics board at Washington University (IRB# 202205053), serving as the single Institutional Review Board for both participating sites. Recruitment began in September 2022. Dissemination plans include presentations at scientific conferences, scientific publications, internet-based educational materials and mass media.

TRIAL REGISTRATION NUMBER

NCT05346588.

Health inequities around gender, disability and internal migration: are local governments doing enough

SETTING

The Kerala health system in India has more than 25 years of decentralised implementation experience. Decentralization could assist in addressing health disparities such as gender, disability, and migration.

OBJECTIVE

To explore how inequity issues comprising gender, disability and internal migrations were being addressed at present by the decentralised Kerala health system.

DESIGN

Our approach was qualitative, using document review, key informant interviews and in-depth interviews with policy makers, health staff and other stakeholders.

RESULTS

Gender aspects were incorporated into planning and budgeting, with 10% funds earmarked for women. Projects were gender-specific to women, and within conventional social roles of livelihood, welfare or reproductive health. Recently, transgender focused projects were also initiated. Schemes for people with disabilities remained welfare-centric and driven by top-down policies. The local governments performed beneficiary identification and benefit disbursal. Migrant health aspects were focused on infectious diseases surveillance and later living conditions of migrant workers.

CONCLUSION

The importance that health systems place on socioeconomic determinants of health and fundamental human rights is reflected in the health interventions for marginalised communities. In Kerala, there is now a passive application of central rules and a reluctance to utilise local platforms. Changing this is a necessary condition for achieving equal development.

Local governments and community-based rehabilitation for developmental disabilities: leaving no one behind

SETTING

The BUDS (not an acronym) institutions comprise a community-based rehabilitation initiative for children and families affected by developmental disabilities in Kerala, India.

OBJECTIVE

To explore the role of local governments in the establishment and functioning of BUDS institutions.

DESIGN

We used qualitative approaches comprising document review and in-depth interviews with trainers, parents of children with developmental disabilities and elected representatives.

RESULTS

BUDS was created by Kudumbasree, a decentralised women empowerment and poverty alleviation initiative. Our findings illustrate the role of local governments in facilitating expansion through the establishment of infrastructure, therapy equipment, transportation and financial allocation for these, as well as through the development of human resources, assistance with enrolment for financial assistance and insurance programmes, and coordination with education and health sectors. Programme implementation varied considerably regarding available infrastructure, staffing and services among the institutions studied. The institutions were physically closed during the COVID-19 pandemic but continued to function in alternative ways.

CONCLUSION

Despite variable implementation, local governments have supported the expansion of BUDS institutions, thereby creating more spaces for inclusive and integrated education and rehabilitation of persons with disabilities in Kerala. The expansion over the past two decades and measures during the COVID-19 pandemic suggest resilience and sustainability of the model.

Successful living donor liver transplantation in a patient with hemophilia A and factor VIII inhibitor: a case report with perioperative recommendations

Liver transplantation in patients with end-stage liver disease and coexisting hemophilia A has been described. Controversy exists over perioperative management of patients with factor VIII inhibitor predisposing patients to hemorrhage. We describe the case of a 58-year-old man with a history of hemophilia A and factor VIII inhibitor, eradicated with rituximab prior to living donor liver transplantation without recurrence of inhibitor. We also provide perioperative management recommendations from our successful multidisciplinary approach.

Intraoperative risk factors of acute kidney injury after liver transplantation

Acute kidney injury (AKI) is one of the most common complications of liver transplantation (LT). We examined the impact of intraoperative management on risk for AKI following LT. In this retrospective observational study, we linked data from the electronic health record with standardized transplant outcomes. Our primary outcome was stage 2 or 3 AKI as defined by Kidney Disease Improving Global Outcomes guidelines within the first 7 days of LT. We used logistic regression models to test the hypothesis that the addition of intraoperative variables, including inotropic/vasopressor administration, transfusion requirements, and hemodynamic markers improves our ability to predict AKI following LT. We also examined the impact of postoperative AKI on mortality. Of the 598 adult primary LT recipients included in our study, 43% (n = 255) were diagnosed with AKI within the first 7 postoperative days. Several preoperative and intraoperative variables including (1) electrolyte/acid-base balance disorder (International Classification of Diseases, Ninth Revision codes 253.6 or 276.x and International Classification of Diseases, Tenth Revision codes E22.2 or E87.x, where x is any digit; adjusted odds ratio [aOR], 1.917, 95% confidence interval [CI], 1.280-2.869; p = 0.002); (2) preoperative anemia (aOR, 2.612; 95% CI, 1.405-4.854; p = 0.002); (3) low serum albumin (aOR, 0.576; 95% CI, 0.410-0.808; p = 0.001), increased potassium value during reperfusion (aOR, 1.513; 95% CI, 1.103-2.077; p = 0.01), and lactate during reperfusion (aOR, 1.081; 95% CI, 1.003-1.166; p = 0.04) were associated with posttransplant AKI. New dialysis requirement within the first 7 days postoperatively predicted the posttransplant mortality. Our study identified significant association between several potentially modifiable variables with posttransplant AKI. The addition of intraoperative data did not improve overall model discrimination.

Antibacterial and anticancer potential of Brassica oleracea var acephala using biosynthesised copper nanoparticles

INTRODUCTION

Brassica oleracea var acephala was studied for preliminary phytochemical screening. The results showed that the ethanolic crude extract of the leaf contain high phytochemical activity hence B.oleracea var acephala is rich in flavonoids, phenolic compounds, carbohydrates and phytosterols.

MATERIALS AND METHODS

The ethanolic extract was used to synthesise copper nanoparticles. The copper nanoparticles were successfully synthesised from copper sulphate solution which was identified by the colour change from dark green colour of the extract. Thus the B.oleracea var acephala is a good source to synthesis copper nanoparticles. The synthesised copper nanoparticles were characterised using Scanning Electron Microscope (SEM) analysis. The SEM image displayed the high-density nanoparticles synthesised by leaf extracts and that the nanoparticles were crystals in shape.

RESULTS

The copper nanoparticles (CNP) bind to the leaf extract. B.oleracea var acephala also has shown the antimicrobial and antioxidant activity. A comparative study was done between ethanolic its crude extract and nanoparticles. Both extracts exhibited zone of inhibition and better antioxidant potential but the CuNPs shows major zone of inhibition and showed more antioxidant activity. Anticancer activity of B.oleracea var acephala against Cervical HeLa cell line was confirmed using ethanolic crude extract and CNP. The results showed that HeLa cells proliferation was inhibited with increasing concentration of ethanolic crude extract and copper nanoparticles. From the results, it was seen that percentage viability of the cancer cells decreased with increased concentration of the samples whereas cytotoxicity against HeLa cell lines increased with the increased concentration of the samples.

CONCLUSION

Thus B.oleracea var acephala possesses anticancer activity against HeLa cell lines.

Association of intraoperative hyperglycemia and postoperative outcomes in patients undergoing non-cardiac surgery: a multicenter retrospective study

BACKGROUND

While pre and postoperative hyperglycemia is associated with increased risk of surgical site infection, myocardial infarction, stroke and risk of death, there are no multicenter data regarding the association of intraoperative blood glucose levels and outcomes for the non-cardiac surgical population.

METHODS

We conducted a retrospective cohort study from the Michigan Surgical Quality Collaborative, a network of 64 hospitals that prospectively collects validated data on surgical patients for the purpose of quality improvement. We included data for adult general, vascular, endocrine, hepatobiliary, and gastrointestinal operations between 2013 and 2015. We assessed the risk-adjusted, independent relationship between intraoperative hyperglycemia (glucose > 180) and the primary outcome of 30-day morbidity/mortality and secondary outcome of infectious complications using multivariable logistic regression modelling. Post hoc sensitivity analysis to assess the association between blood glucose values ≥250 mg/dL and outcomes was also performed.

RESULTS

Ninety-two thousand seven hundred fifty-one patients underwent surgery between 2013 and 2015 and 5014 (5.4%) had glucose testing intra-operatively. Of these patients, 1647 patients (32.9%) experienced the primary outcome, and 909 (18.1%) the secondary outcome. After controlling for patient comorbidities and surgical factors, peak intraoperative glucose > 180 mg/dL was not an independent predictor of 30-day mortality/morbidity (adjusted OR 1.05, 95%CI:0.86 to 1.28; p-value 0.623; model c-statistic of 0.720) or 30-day infectious complications (adjusted OR 0.93, 95%CI:0.74,1.16; p 0.502; model c-statistic of 0.709). Subgroup analysis for patients with or without diabetes yielded similar results. Sensitivity analysis demonstrated blood glucose of 250 mg/dL was a predictor of 30-day mortality/morbidity (adjusted OR: 1.59, 95% CI: 1.24, 2.05; p < 0.001).

CONCLUSIONS

Among more than 5000 patients across 64 hospitals who had glucose measurements during surgery, there was no difference in postoperative outcomes between patients who had intraoperative glucose > 180 mg/ dL compared to patients with glucose values ≤180 mg/ dL.

Intraoperative glycemic control in patients undergoing Orthotopic liver transplant: a single center prospective randomized study

Background

Perioperative hyperglycemia is associated with poor outcomes yet evidence to guide intraoperative goals and treatment modalities during non-cardiac surgery are lacking. End-stage liver disease is associated with altered glucose homeostasis; patients undergoing liver transplantation display huge fluctuations in blood glucose (BG) and represent a population of great interest. Here, we conduct a randomized trial to compare the effects of strict versus conventional glycemic control during orthotopic liver transplant (OLT).

Methods

Following approval by the Institutional Review Board of the University of Michigan Medical School and informed consent, 100 adult patients undergoing OLT were recruited. Patients were randomized to either strict (target BG 80–120 mg/dL) or conventional (target BG 180–200 mg/dL) BG control with block randomization for diabetic and nondiabetic patients. The primary outcomes measured were 1-year patient and graft survival assessed on an intention to treat basis. Graft survival is defined as death or needing re-transplant (www.unos.org). Three and 5-year patient and graft survival, infectious and biliary complications were measured as secondary outcomes. Data were examined using univariate methods and Kaplan-Meir survival analysis. A sensitivity analysis was performed to compare patients with a mean BG of ≤120 mg/dL and those > 120 mg/dL regardless of treatment group.

Results

There was no statistically significant difference in patient survival between conventional and strict control respectively;1 year, 88% vs 88% (p-0.99), 3 years, 86% vs 84% (p- 0.77), 5 years, 82% vs 78. % (p-0.36). Graft survival was not different between conventional and strict control groups at 1 year, 88% vs 84% (p-0.56), 3 years 82% vs 76% (p-0.46), 5 years 78% vs 70% (p-0.362).

Conclusion

There was no difference in patient or graft survival between intraoperative strict and conventional glycemic control during OLT.

Trial registration

Clinical trial number and registry: www.clinicaltrials.gov NCT00780026. This trial was retrospectively registered on 10/22/2008.

The impact of intraoperative fluid management during laparoscopic donor nephrectomy on donor and recipient outcomes

BACKGROUND

Intraoperative fluid management during laparoscopic donor nephrectomy (LDN) may have a significant effect on donor and recipient outcomes. We sought to quantify variability in fluid management and investigate its impact on donor and recipient outcomes.

METHODS

A retrospective review of patients who underwent LDN from July 2011 to January 2016 with paired kidney recipients at a single center was performed. Patients were divided into tertiles of intraoperative fluid management (standard, high, and aggressive). Donor and recipient demographics, intraoperative data, and postoperative outcomes were analyzed.

RESULTS

Overall, 413 paired kidney donors and recipients were identified. Intraoperative fluid management (mL/h) was highly variable with no correlation to donor weight (kg) (R = 0.017). The aggressive fluid management group had significantly lower recipient creatinine levels on postoperative day 1. However, no significant differences were noted in creatinine levels out to 6 months between groups. No significant differences were noted in recipient postoperative complications, graft loss, and death. There was a significant increase (P < 0.01) in the number of total donor complications in the aggressive fluid management group.

CONCLUSIONS

Aggressive fluid management during LDN does not improve recipient outcomes and may worsen donor outcomes compared to standard fluid management.

Intraoperative hyperglycemia is independently associated with infectious complications after non-cardiac surgery

Background

Perioperative hyperglycemia and its associated increase in morbidity and mortality have been well studied in the critical care and cardiac surgery literature. However, there is little data regarding the impact of intraoperative hyperglycemia on post-operative infectious complications in non-cardiac surgery.

Methods

All National Surgery Quality Improvement Program patients undergoing general, vascular, and urological surgery at our tertiary care center were reviewed. After integrating intraoperative glucose measurements from our intraoperative electronic health record, we categorized patients as experiencing mild (8.3–11.0 mmol/L), moderate (11.1–16.6 mmol/L), and severe (≥ 16.7 mmol/L) intraoperative hyperglycemia. Using multiple logistic regression to adjust for patient comorbidities and surgical factors, we evaluated the association of hyperglycemia with the primary outcome of postoperative surgical site infection, pneumonia, urinary tract infection, or sepsis within 30 days.

Results

Of 13,954 patients reviewed, 3150 patients met inclusion criteria and had an intraoperative glucose measurement. 49% (n = 1531) of patients experienced hyperglycemia and 15% (n = 482) patients experienced an infectious complication. Patients with mild (adjusted odds ratio 1.30, 95% confidence interval [1.01 to 1.68], p-value = 0.04) and moderate hyperglycemia (adjusted odds ratio 1.57, 95% confidence interval [1.08–2.28], p-value = 0.02) had a statistically significant risk-adjusted increase in infectious complications. The model c-statistic was 0.72 [95% confidence interval 0.69–0.74].

Conclusions

This is one of the first studies to demonstrate an independent relationship between intraoperative hyperglycemia and postoperative infectious complications. Future studies are needed to evaluate a causal relationship and impact of treatment.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0546-0) contains supplementary material, which is available to authorized users.

Interrogation of a longitudinal, national pharmacy claims dataset to explore factors that predict the need for add-on therapy in older and socioeconomically disadvantaged Australians with type 2 diabetes mellitus patients (T2DM)

PURPOSE

The management of type 2 diabetes mellitus (T2DM) is complex. The aim of this work is to explore factors that predict the need for add-on therapy in patients with T2DM in the community.

METHODS

We accessed longitudinal, pharmacy payment claim records from the national Pharmaceutical Benefits Scheme (PBS) (Subsidises costs of medicines: government pays difference between patient co-payments, lower in concessional patients, and additional cost of drug.) for the period January 2006 to September 2014 (EREC/MI3127) from a 10% random sample of the Australian population validated to be representative of the population by the Australian Bureau of Statistics (ABS). Likely, T2DM patients were identified as those having been dispensed a single anti-hyperglycaemic drug (monotherapy). The time taken and possible factors that might lead to the addition of a second therapy were examined. An examination was made of trends in the co-prescription of either antihypertensive or anti-hyperlipidaemic agents in relation to the time (± 3 years) of initiating an anti-hyperglycaemic agent.

RESULTS

Most (83%) presumed T2DM patients were initiated with metformin. The average time until the second agent was added was 4.8 years (95% CI 4.7-4.9). Satisfactory adherence, age, male gender, initiating therapy after 2012 and initiating with a sulphonylurea drug all were significant risks for add-on therapy. There was no overall trend in the initiation of antihypertensive and/or anti-hyperlipidaemic agents with respect to the time of anti-hyperglycaemic initiation.

CONCLUSION

The usefulness of a longitudinal dataset of pharmacy-claim records is demonstrated. Over half of all older and socioeconmically disadvantaged T2DM patients captured in this longitudinal claims database will be prescribed a second anti-hyperglycaemic agent within 5 years of their first drug therapy. Several factors can predict the risk of prescription of add-on therapy, and these should be considered when prescribing medications to treat T2DM.

A dosing algorithm for metformin based on the relationships between exposure and renal clearance of metformin in patients with varying degrees of kidney function

PURPOSE

The aims of this study were to investigate the relationship between metformin exposure, renal clearance (CL_R), and apparent non-renal clearance of metformin (CL_NR/F) in patients with varying degrees of kidney function and to develop dosing recommendations.

METHODS

Plasma and urine samples were collected from three studies consisting of patients with varying degrees of kidney function (creatinine clearance, CL_CR; range, 14-112 mL/min). A population pharmacokinetic model was built (NONMEM) in which the oral availability (F) was fixed to 0.55 with an estimated inter-individual variability (IIV). Simulations were performed to estimate AUC_0-τ, CL_R, and CL_NR/F.

RESULTS

The data (66 patients, 327 observations) were best described by a two-compartment model, and CL_CR was a covariate for CL_R. Mean CL_R was 17 L/h (CV 22%) and mean CL_NR/F was 1.6 L/h (69%).The median recovery of metformin in urine was 49% (range 19-75%) over a dosage interval. When CL_R increased due to improved renal function, AUC_0-τ decreased proportionally, while CL_NR/F did not change with kidney function. Target doses (mg/day) of metformin can be reached using CL_CR/3 × 100 to obtain median AUC_0-12 of 18-26 mg/L/h for metformin IR and AUC_0-24 of 38-51 mg/L/h for metformin XR, with C_max < 5 mg/L.

CONCLUSIONS

The proposed dosing algorithm can be used to dose metformin in patients with various degrees of kidney function to maintain consistent drug exposure. However, there is still marked IIV and therapeutic drug monitoring of metformin plasma concentrations is recommended.

Patterns of care in geriatric cancer patients - An audit from a rural based hospital cancer registry in Kerala

BACKGROUND

There is deficit of data from India on elderly patients with cancer. Comprehensive geriatric assessment may lead to a better decision making capacity in this population. However, routine implementation of such assessment is resource consuming.

AIM

The aim of this study was to determine the patterns of care in elderly patients treated at a tertiary rural cancer center in India.

MATERIALS AND METHODS

All patients with age 70 or above with solid tumors without any definitive treatment prior to the registration at our center and registered between 01/01/2010 and 31/12/2011 were selected for this study. The baseline demographic pattern and the pattern of care of treatment were analyzed. SPSS version 16 (IBM Inc, Armonk, New York, U.S.) was used for analysis. Descriptive data are provided.

RESULTS

A total of 761 patients were evaluable subject to the aforementioned inclusion criteria. The median age of this cohort was 75 years (70-95 years). The most frequent primary sites of malignancies in 451 males were head neck (32.4%), lung (23.3%) and gastrointestinal (23.3%). In 310 females, the most common sites were head neck (31.6%), gynecological (18.4%) and gastrointestinal (24.5%). 228 (30%) of the patients had localized disease, 376 (49.4%) had loco-regionally advanced disease and 145 (19.1%) had distant metastases at presentation. 334 (46.32%) of patients were treated with curative intent. On logistic regression analysis the factors that predicted use of curative intent treatment were age <75 years, performance status 0-1, primary site and clinical extent of disease.

CONCLUSION

Routine comprehensive geriatric assessment needs to be implemented in our setting as almost 50% of our geriatric patients undergo curative intent treatment.

Characterization of Landsat-7 to Landsat-8 reflective wavelength and normalized difference vegetation index continuity

At over 40 years, the Landsat satellites provide the longest temporal record of space-based land surface observations, and the successful 2013 launch of the Landsat-8 is continuing this legacy. Ideally, the Landsat data record should be consistent over the Landsat sensor series. The Landsat-8 Operational Land Imager (OLI) has improved calibration, signal to noise characteristics, higher 12-bit radiometric resolution, and spectrally narrower wavebands than the previous Landsat-7 Enhanced Thematic Mapper (ETM+). Reflective wavelength differences between the two Landsat sensors depend also on the surface reflectance and atmospheric state which are difficult to model comprehensively. The orbit and sensing geometries of the Landsat-8 OLI and Landsat-7 ETM+ provide swath edge overlapping paths sensed only one day apart. The overlap regions are sensed in alternating backscatter and forward scattering orientations so Landsat bi-directional reflectance effects are evident but approximately balanced between the two sensors when large amounts of time series data are considered. Taking advantage of this configuration a total of 59 million 30m corresponding sensor observations extracted from 6,317 Landsat-7 ETM+ and Landsat-8 OLI images acquired over three winter and three summer months for all the conterminous United States (CONUS) are compared. Results considering different stages of cloud and saturation filtering, and filtering to reduce one day surface state differences, demonstrate the importance of appropriate per-pixel data screening. Top of atmosphere (TOA) and atmospherically corrected surface reflectance for the spectrally corresponding visible, near infrared and shortwave infrared bands, and derived normalized difference vegetation index (NDVI), are compared and their differences quantified. On average the OLI TOA reflectance is greater than the ETM+ TOA reflectance for all bands, with greatest differences in the near-infrared (NIR) and the shortwave infrared bands due to the quite different spectral response functions between the sensors. The atmospheric correction reduces the mean difference in the NIR and shortwave infrared but increases the mean difference in the visible bands. Regardless of whether TOA or surface reflectance are used to generate NDVI, on average, for vegetated soil and vegetation surfaces (0 ≤ NDVI ≤ 1), the OLI NDVI is greater than the ETM+ NDVI. Statistical functions to transform between the comparable sensor bands and sensor NDVI values are presented so that the user community may apply them in their own research to improve temporal continuity between the Landsat-7 ETM+ and Landsat-8 OLI sensor data. The transformation functions were developed using ordinary least squares (OLS) regression and were fit quite reliably (r ² values >0.7 for the reflectance data and >0.9 for the NDVI data, p-values <0.0001).

Potentiation of convergent synaptic inputs onto pyramidal neurons in somatosensory cortex: dependence on brain wave frequencies and NMDA receptor subunit composition

N-methyl-d-aspartate receptors (NMDARs) at layer (L)1/primary whisker motor cortex synaptic inputs are distinct from thalamic/striatal (Str) synaptic inputs onto L5 pyramidal neurons in the rat somatosensory cortex. However, the consequences of differential expression of putative GluN3A-containing triheteromeric NMDARs at L1 inputs and GluN2A-containing diheteromeric NMDARs at Str inputs on plasticity of the underlying synapses at the respective inputs remain unknown. Here we demonstrate that L1, but not Str, synapses are potentiated following delta burst stimulation (dBS). This potentiation is blocked by d-serine and/or intracellular 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) suggesting that it is subunit-specific and dependent on elevations in intracellular Ca(2+). Interestingly, ifenprodil, the GluN2B-preferring antagonist, suppresses baseline L1 responses but does not prevent induction of dBS-evoked potentiation. Unlike L1, Str synapses are maximally potentiated following theta burst stimulation (tBS) and this potentiation is blocked with BAPTA and/or the GluN2A-preferring antagonist NVP-AAM077. We show further that while dBS is both necessary and sufficient to potentiate L1 synapses, tBS is most effective in potentiating Str synapses. Our data suggest distinct potentiating paradigms for the two convergent inputs onto pyramidal neurons in the somatosensory cortex and co-dependence of synaptic potentiation on brain wave-tuned frequencies of burst stimulation and subunit composition of underlying NMDARs. A model for predicting the likelihood of enhancing synaptic efficacy is proposed based on Ca(2+) influx through these receptors and integration of EPSPs at these inputs. Together, these findings raise the possibility of input-specific enhancements of synaptic efficacy in neurons as a function of the animal's behavioral state and/or arousal in vivo.

Comparing dose prediction software used to manage gentamicin dosing

BACKGROUND

Current Australian guidelines recommend initiating directed therapy of gentamicin if administration exceeds 48 h. Directed doses of gentamicin require the monitoring of plasma concentrations of gentamicin to determine the 24-h area under the time course of plasma gentamicin concentrations (AUC) and a dosage prediction program, for example TCIWorks or Aladdin. However, doses calculated by such programs have not been compared with an established program.

AIM

To compare the directed dosage of gentamicin calculated by TCIWorks, Aladdin and an Excel-based program, with an established program, Abbottbase.

METHODS

Peak and trough plasma concentrations after the first and second administered doses of gentamicin were available from three patient groups (n = 20-23) with varying creatinine clearances (<40, 40-80, >80 mL/min). The directed dose needed to produce 24-h AUC values of 80 mg.h/L was calculated using each program.

RESULTS

There was a strong correlation between the directed doses predicted by each of the three programs compared with Abbottbase, following the first administered dose (r(2) > 0.97, P < 0.0001). The mean ratio (90% confidence intervals) of these directed doses of the gentamicin were: TCIWorks/Abbottbase 106% (105-107%), Aladdin/Abbottbase 102% (101-103%) and Excel/Abbottbase 108% (106-109%). The correlations and dose ratios were also similar when comparisons were made following the second administered dose. For each of the three renal function groups, all programs yielded similar directed doses.

CONCLUSIONS

The four programs used in the calculation of directed doses of gentamicin yielded similar results. Any would be suitable for use in clinical practice.

A Comparative Study on Effect of Oral Administration of Turmeric and Nutmeg on Memory Boosting and Regaining in Wistar Albino Rats

BACKGROUND AND OBJECTIVES: Although a few drugs are available today for the management of Alzheimer's disease (AD) and many plants and their extracts are extensively employed in animal studies and AD patients, yet no substantial drug or plant extract is able to reverse the AD symptoms adequately. It is tangible that there has been augmenting need for such therapeutic intervention. The present study was undertaken with an objective to compare the memory boosting and regaining effects of oral administration of nutmeg and turmeric which are used commonly as spice in various dishes, as components of teas and soft drinks. MATERIAL AND METHODS: A total of 24 male and female wistar albino rats were used for this study. They were randomly assigned into three groups with 8 rats in each group. The influence of oral intake of nutmeg and turmeric extract on behavioral task performance was studied by using T-maze and radial arm maze and physiological measures relative to a milk control group was investigated. RESULTS: We have observed significant memory boosting and memory regaining effects of nutmeg when administered orally when compared with control group..However, nutmeg is having strong memory regaining effect than turmeric. CONCLUSION: We conclude that nutmeg is having strong memory regaining effect than turmeric. However further pharmacological and biochemical investigations will clearly elucidate the mechanism of action and helpful in projecting these plant extracts as a therapeutic target in diabetes research. DOI: http://dx.doi.org/10.3126/jucms.v1i3.8765   Journal of Universal College of Medical Sciences Vol.1(3) 2013: 46-52

Bovine carriers of Anaplasma marginale and Anaplasma bovis in South India

Carriers of bovine anaplasmosis in Northern Kerala, South India were detected using conventional microscopical and molecular techniques. PCR-RFLP and nested PCR techniques were used for detection of Anaplasma marginale and Anaplasma bovis respectively and the PCR products were confirmed by sequencing. Out of 150 samples tested, 25 were detected positive for A. marginale and five for A. bovis based on molecular tests. The inclusion bodies of A. marginale could be detected by microscopy in two blood smears after staining by giemsa while acridine orange staining detected three smears positive. The data clearly suggest the higher sensitivity of molecular techniques for diagnosis of these diseases.

Metformin therapy in patients with chronic kidney disease

Metformin therapy is limited in patients with chronic kidney disease (CKD) due to the potential risk of lactic acidosis. This open-label observational study investigated metformin and lactate concentrations in patients with CKD (n = 22; creatinine clearances 15-40 ml/min) and in two dialysed patients. Patients were prescribed a range of metformin doses (250-2000 mg daily) and metformin concentrations were compared with data from healthy subjects (scaled to 1500 mg twice daily). A subset of patients (n = 7) was controlled on low doses of metformin (250 or 500 mg daily). No correlation between metformin and lactate concentrations was observed. Three patients had high lactate concentrations (>2.7 mmol/l) and two had high metformin concentrations (3-5 mg/l), but none had any symptoms of lactic acidosis. Reducing metformin dosage and monitoring metformin concentrations will allow the safe use of metformin in CKD, provided that renal function is stable.

Triheteromeric N-methyl-D-aspartate receptors differentiate synaptic inputs onto pyramidal neurons in somatosensory cortex: involvement of the GluN3A subunit

N-methyl-D-aspartate receptors (NMDARs) are glutamatergic by virtue of glutamate-binding GluN2 subunits and glycinergic by virtue of glycine-binding GluN1 and GluN3 subunits. The existence, location, and functional-significance of NMDARs containing both GluN2 and GluN3 subunits have as yet remained unelucidated. Here we report on the discovery and characterization of a novel type of NMDARs, found at layer (L)1/primary whisker-motor-cortex inputs onto L5 pyramidal neurons in somatosensory cortex, that are distinct in structure and function from conventional GluN2A-containing NMDARs at thalamic/striatal (Str) inputs onto the same neurons. These receptors had a threshold-like activation at hyperpolarized holding-potentials with strong outward rectification of their current-voltage relationships unlike any known GluN1/GluN2-containing NMDARs. Pharmacology revealed a triheteromeric-receptor with features common to glutamate-activated GluN1/GluN2-containing and glycine-activated GluN1/GluN3-containing diheteromeric NMDARs. However, unlike GluN1/GluN3 receptors, NMDARs at L1 inputs were activated by glutamate and blocked by d-AP5, Ca(2+)-permeable, and more efficient at integrating and potentiating EPSPs selectively over Str inputs during high-frequency stimulation while obviating the need for AMPAR-mediated depolarization.

Effects of asthma and inhalation corticosteroids on the dental arch morphology in children

BACKGROUND

Hereditary, environmental and developmental factors play an important role in dentofacial development, as well as the initiation of malocclusion disorder. Allergic phenomenon such as asthma that induces an alternative mode of breathing in patients is a contributing factor in development of the dental arch.

AIM

Our aim in this study was to evaluate the dentoalveolar morphology in asthmatic children and to analyze the effects of asthmatic medications on the dental arch.

SETTING AND DESIGN

This study is centered on 44 asthmatic children aged between 6-12 years from J.S.S Hospital, Mysore. Selected variables from model analysis of the casts of the asthmatic group were subjected to comparison with those of the non-asthmatic group, which comprised of 44 non-asthmatic children. Selected parameters were arch width, arch length and palatal depth.

MATERIALS AND METHODS

Impressions of upper and lower arches were made with rubber based impression material. A sliding digital caliper was used to measure the casts for arch width and arch length. A palatal depth gauge was used to measure the palatal depth.

STATISTICAL ANALYSIS

Differences in arch widths, arch lengths and palatal depths between asthmatics and non-asthmatics groups were evaluated by independent sample t-tests. Chi-square test was applied to assess the frequency of occurrence of malocclusion in the asthmatic children.

RESULT

The results obtained revealed that the arch length and palatal depth of asthmatic group had higher values compared to that of non-asthmatic groups for both age groups (6 to 8-year-old males and females, 10 to 12-year-old males and females). Inter molar width showed a significant lower value in asthmatics in the maxillary arches of 10 to 12-year-old females. Fifty percent of the asthmatic children aged 10 to 12-years had open-bite. Children under regular medication showed significant deviation in the dentoalveolar morphology as compared to those under irregular medication.

CONCLUSION

The present study proves a strong relation between asthma and dentoalveolar morphology.

Haemoprotozoa of cattle in Northern Kerala, India

A cross-sectional study was conducted using 150 blood samples collected from apparently normal / healthy crossbred cattle of Northern Kerala, South India, for detection of haemoprotozoan infections using staining techniques (Giemsa and Acridine Orange) and specific PCR. Theileria like piroplasms and Babesia bigemina were the only protozoan organisms detected in blood smears. Polymerase chain reaction using specific primers revealed amplification of products specific for Trypanosoma evansi (34.6%), Theileria sp. other than T. annulata (16%) and B. bigemina (0.6%). The higher prevalence rate of Trypanosoma evansi indicated that the subclinical parasitism can be due to higher prevalence of tabanid flies. The study also revealed the presence of a theilerial piroplasm other than T. annulata in North Kerala, which needs further investigation.

Mesh fixation in laparoscopic repair of ventral hernia: a new method

During laparoscopic repair of ventral hernia, optimal fixation of the prosthetic mesh to the abdominal wall includes transfascial fixation with sutures in addition to fixation with a stapling, clipping, or tacking device. With the current methods, intracorporeal passage grasping and retrieval of sutures from the abdominal cavity are technically difficult. The reason for this difficulty is the lack of three-dimensional visual feedback during conventional laparoscopy. An easier method is needed. A new method using T-shaped anchors (T-anchors) is described. A T-anchor is a horizontal bar made of rigid titanium that is attached to a vertical limb made of monofilament suture. T-anchors are deployed in pairs, through a needle, and are tied over a musculofascial bridge to achieve transfascial fixation of the mesh to the abdominal wall. This method eliminates the need for intracorporeal grasping and retrieval of the sutures.

Pattern of skin diseases in an Indian village

Disease pattern in a given population is generally determined by different ecological factors. Thus the objective of our study was to find out the pattern of skin diseases in a given population. Analysis of 3673 patients attending a medical camp at Kumble in Kerala state showed 410(11.16%) patients with dermatological problems. 260(63.41%) of them were males and 150(36.59%) females with a male to female ratio of 1.7:1. Of these patients, 178(43.41%) had cutaneous infections and 234(57.07%) had non-infectious dermatoses. Few patients had more than one dermatoses. Fungal infection was the commonest infection seen (22.92%) and eczemas took an upper hand in non-infectious group (32.19%). Improvement in the standard of living, education of the general public, improvement in the environmental sanitation and good nutritious food may help us to bring down the skin disease in this area.

Cutaneous manifestations of non-Hodgkin's lymphoma

Thirty-two confirmed cases of non -Hodgkin's lymphoma (NHL) were examined for cutaneous manifestations for a period of 2 years from November 1998 in KMC Hospital Attavar, Mangalore. Cutaneous manifestations in the study group were compared to a control group of 32 patients. Specific infiltrates were present in all (5/5) CTCL patients and one out of twenty-seven patients with low grade NHL. Morphologically they presented as papules, plaques, nodules and erythroderma. Infective conditions seen in the study group were superficial fungal (7/32) and viral infections (2/ 32). Non-infective conditions were acquired ichthyosis (10/32), generalised pruritus (5/32), insect bite reaction (1/32) and drug eruption (1/32). When compared to control patients only acquired ichthyosis and generalised pruritus were found to be statistically significant. The study group also showed changes due to chemotherapy like diffuse alopecia (24/29), bluish pigmentation of proximal part of nail (4/29), localised pigmentation of palms and soles (1 /29), diffuse pigmentation at injection site (1 /29), pigmentation at scar site (1 /29) and stomatitis (4/29).

Drug susceptibility of Mycobacterium leprae: a retrospective analysis of mouse footpad inoculation results from 1983 to 1997

We analysed the results of mouse foot pad (MFP) tests performed between 1983 and 1997 in our laboratory for the cases referred with clinical suspicion of relapse/drug resistance. A total of 214 cases, with clinical suspicion of relapse/drug resistance were investigated for susceptibility to the drugs of MDT by MFP inoculation. Among 96 inoculations that showed conclusive results, 81 (84%) were fully sensitive to dapsone, suggesting that most of the clinically suspected relapse is due to drug susceptible Mycobacterium leprae. Of the remaining 15 strains (16%) found resistant to dapsone, 13 (87%) were of high grade resistance and one strain each of intermediate grade and low grade dapsone resistance, suggesting that most of the dapsone resistance is secondary in nature. No case of rifampicin resistance was found. Only one case of combined dapsone and unconfirmed clofazimine resistance was found. No other combined multidrug resistance was observed in our analysis.

Intestinal parasitic infection in HIV infected patients with diarrhoea in Chennai

PURPOSE

To determine the prevalence of intestinal parasites in HIV patients with and without diarrhoea in Chennai.

METHODS

A total of 150 stool samples, 41 - acute diarrhoea, 59 - chronic diarrhoea and 50 control samples without diarrhoea were collected and examined for enteric parasites by microscopy.

RESULTS

Enteric parasites were detected in 39% patients with diarrhoea compared to 14% in patients without diarrhoea. Isospora belli was found in 18.6% (11/59) of chronic diarrhoea and 7.3% (3/41) in acute diarrhoea (P > 0.2). Cryptosporidium was detected in 7 cases each in acute and chronic diarrhoea, which was statistically insignificant as compared to the control group (P> 0.05). Microsporidia and Cyclospora cayetanensis associated diarrhoea were detected in only one chronic case each 1/59 (1.69 %).

CONCLUSIONS

Isospora belli appeared to be a predominant parasite associated with diarrhoea among HIV patients. Detection rate of Microsporidia and Cyclospora was found to be very low.

Properties of excitatory synaptic connections mediated by the corpus callosum in the developing rat neocortex

Despite the major role of excitatory cortico-cortical connections in mediating neocortical activities, little is known about these synapses at the cellular level. Here we have characterized the synaptic properties of long-range excitatory-to-excitatory contacts between visually identified layer V pyramidal neurons of agranular frontal cortex in callosally connected neocortical slices from postnatal day 13 to 21 (P13-21) rats. Midline stimulation of the corpus callosum with a minimal stimulation paradigm evoked inward excitatory postsynaptic currents (EPSCs) with an averaged peak amplitude of 56.5 +/- 5 pA under conditions of whole cell voltage clamp at -70 mV. EPSCs had fixed latencies from stimulus onset and could follow stimulus trains (1-20 Hz) without changes in kinetic properties. Bath application of 2,3-dihydro-6-nitro-7-sulfamoyl-benzo(F)quinoxaline (NBQX) abolished these responses completely, indicating that they were mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors (AMPARs). Evoked responses were isolated in picrotoxin to yield purely excitatory PSCs, and a low concentration of NBQX (0.1 microM) was used to partially block AMPARs and prevent epileptiform activity in the tissue. Depolarization of the recorded pyramidal neurons revealed a late, slowly decaying component that reversed at approximately 0 mV and was blocked by D-2-amino-5-phosphonovaleric acid. Thus AMPA and N-methyl-D-aspartate receptors (NMDARs) coexist at callosal synapses and are likely to be activated monosynaptically. The peak amplitudes and decay time constants for EPSCs evoked using minimal stimulation (+/-40 mV) were similar to spontaneously occurring sEPSCs. Typical conductances associated with AMPA and NMDAR-mediated components, deduced from their respective current-voltage (I-V) relationships, were 525 +/- 168 and 966 +/- 281 pS, respectively. AMPAR-mediated responses showed age-dependent changes in the rectification properties of their I-V relationships. While I-Vs from animals >P15 were linear, those in the younger (<P16) age group were inwardly rectifying. Although Ca2+ permeability in AMPARs can be correlated with inward rectification, outside-out somatic patches from younger animals were characterized by Ca2+-impermeable receptors, suggesting that somatic receptors might be functionally different from those located at synapses. While the biophysical properties of AMPAR components of callosally-evoked EPSCs were similar to those evoked by stimulation of local excitatory connections, the NMDA component displayed input-specific differences. NMDAR-mediated responses for local inputs were activated at more hyperpolarized holding potentials in contrast with those evoked by callosal stimulation. Paired stimuli used to assay presynaptic release properties showed paired-pulse depression (PPD) in animals <P16, which converted to facilitation (PPF) in older animals, suggesting a developmental transition from low probability of transmitter release to high P(r) at these synapses and/or alterations in the properties of the underlying postsynaptic receptors. Physiologic properties of neocortical e-e connections are thus input specific and subject to developmental changes in their postsynaptic receptors.

Scavenging of reactive oxygen species by chlorophyllin: an ESR study

The antioxidant effects of chlorophyllin (CHL), a water-soluble analog of the green plant pigment chlorophyll, on different reactive oxygen species (ROS) were investigated by electron spin resonance (ESR) spectroscopy. As a standard, we have used the ability of CHL to scavenge the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. CHL inhibits the formation of 5,5-dimethyl-1-pyrroline-N-oxide adduct with hydroxyl radical (DMPO-.OH adduct) generated by gamma-radiation in a dose-dependent manner. At a concentration of 1 mM, CHL caused more than 90% inhibition of ESR signal intensity of this adduct. However, the results obtained with the Fenton reaction were different. We also found evidence for the inhibition of 1O2-dependent formation of the 2,2,6,6-tetramethyl-piperidine oxide (TEMPO) radical during photosensitization of methylene blue with visible light. CHL was also able to inhibit hydrogen peroxide induced oxidation of phenol red. The rate constant of the reaction of CHL with H2O2 was found to be 2.7 x 10(6) M-1 s-1. In conclusion, CHL has potent antioxidant ability involving scavenging of various physiologically important ROS.

Extrusion of actin-positive strands from Hep-2 and Int 407 cells caused by outer membrane preparations of enteropathogenic Escherichia coil and specific attachment of wild type bacteria to the strands

Enteropathogenic Escherichia coli (EPEC) causes persistent infantile diarrhoea. This nontoxigenic E. coli exhibits a complicated pathogenic mechanism in which its outer membrane proteins and type III secretory proteins damage intestinal epithelium and cause diarrhoea. In accordance with this, our previous study using HEp-2 cells demonstrated cytopathic effects caused by cell-free outer membrane preparations of EPEC. In this study, we report the extrusion of actin-positive strands from HEp-2 and Int 407 cells when treated with outer membrane preparations. An interesting observation of this work, perhaps relevant to the characteristic localized three-dimensional colony formation of EPEC, is the attachment of a wild type EPEC strain to these actin-positive strands.

Mechanism of protection against radiation-induced DNA damage in plasmid pBR322 by caffeine

PURPOSE

Caffeine (1,3,7-trimethyl xanthine), a dietary component, has been shown to have widely varying effects on DNA damage induced by UV and ionizing radiation, depending upon pre- or post-irradiation administration and its concentration. Caffeine administered post-UV irradiation is known to inhibit enzymatic repair of DNA lesions, leading to potentiation of damage, whereas its presence before or during irradiation elicits protection in a wide range of test systems: bacteria, cultured human cells, plant seeds and mouse. The purpose of this study is to test whether caffeine present during gamma-irradiation of plasmid DNA, a system devoid of replication and repair, could elicit protection by scavenging free radicals.

MATERIALS AND METHODS

Plasmid pBR322 DNA was exposed to gamma-radiation in the presence or absence of caffeine at a dose-rate of 1.20 Gy min(-1) and damage measured as single-strand breaks. To understand the mechanisms of the observed protection, especially under oxic conditions, reaction of caffeine with superoxide radical (O(2)(-)), hydrogen peroxide (H(2)O(2)) and the deoxyribose peroxyl radical (ROO(*)) were studied.

RESULTS

Irradiation of pBR322 was observed to induce a dose-dependent increase in single-strand breaks. Caffeine itself did not induce strand breaks but reduced radiation-induced strand breaks at micromolar to millimolar concentrations. Caffeine has been shown to react with the radiation-derived oxidants. The reaction rate constants observed were 7.5x10(1) M(-1) s(-1) with O(2)(-) 1.05x10(8) M(-1) s(-1) with ROO(*) and 8.8x10(1) M(-1) s(-1) with H(2)O(2).

CONCLUSIONS

Caffeine effectively protects DNA against ionizing radiation in a system devoid of repair and replication machinery. Thus, DNA protection shown by caffeine is possibly due to the scavenging of radiation-derived primary as well as secondary reactive oxygen species, and this physicochemical protective pathway possibly pre-empts any subsequent inhibitory effect of caffeine on the enzymatic repair of DNA.

Excessive free radical generation in the blood of children suffering from asthma

The aim of the present study is to evaluate the biochemical parameters in blood relevant to oxygen free radicals and antioxidant defenses in children with asthma. A total of 210 asthmatic children, aged 5-18 years, were studied at two different times, once during a severe episode of wheeze (during episode category) and the other after recovery (resting condition). A total of 180 healthy children participated in the study as age and sex matched healthy controls. Superoxide and hydroxyl radical assays were used as a measure of free radical formation. Antioxidant enzymes and free radical scavengers in blood were also assayed. Lipid peroxidation products were assayed in plasma and erythrocytes to evaluate the imbalance (if any) between oxidant (radical) formation and their inactivation. Serum IgE concentrations and peak expiratory flow rate (PEFR) were used as measures of allergic reactions and residual lung capacity, respectively. Excessive production of superoxide and hydroxyl radicals were noted in the blood cells in asthmatics and were correlated to the severity of disease measured as PEFR. Superoxide dismutase and free radical scavengers in blood were significantly lower in asthma, even during resting condition. The present observations endorse the correlation between disease severity and oxygen radical production in asthma subjects. Oxygen metabolites may play a direct or indirect role in the modulation of airway inflammation. Excessive superoxide and hydroxyl radical production may be used as a marker for susceptibility to asthma and for monitoring therapeutic measures.

PALI-a database of Phylogeny and ALIgnment of homologous protein structures

PALI (release 1.2) contains three-dimensional (3-D) structure-dependent sequence alignments as well as structure-based phylogenetic trees of homologous protein domains in various families. The data set of homologous protein structures has been derived by consulting the SCOP database (release 1.50) and the data set comprises 604 families of homologous proteins involving 2739 protein domain structures with each family made up of at least two members. Each member in a family has been structurally aligned with every other member in the same family (pairwise alignment) and all the members in the family are also aligned using simultaneous super-position (multiple alignment). The structural alignments are performed largely automatically, with manual interventions especially in the cases of distantly related proteins, using the program STAMP (version 4.2). Every family is also associated with two dendrograms, calculated using PHYLIP (version 3.5), one based on a structural dissimilarity metric defined for every pairwise alignment and the other based on similarity of topologically equivalent residues. These dendrograms enable easy comparison of sequence and structure-based relationships among the members in a family. Structure-based alignments with the details of structural and sequence similarities, superposed coordinate sets and dendrograms can be accessed conveniently using a web interface. The database can be queried for protein pairs with sequence or structural similarities falling within a specified range. Thus PALI forms a useful resource to help in analysing the relationship between sequence and structure variation at a given level of sequence similarity. PALI also contains over 653 'orphans' (single member families). Using the web interface involving PSI_BLAST and PHYLIP it is possible to associate the sequence of a new protein with one of the families in PALI and generate a phylogenetic tree combining the query sequence and proteins of known 3-D structure. The database with the web interfaced search and dendrogram generation tools can be accessed at http://pauling.mbu.iisc.ernet. in/ approximately pali.

Resistance to arsenite modulates levels of alpha-tubulin and sensitivity to paclitaxel in Leishmania donovani

Tubulin expression is known to alter due to drug resistance. Differentiation of Leishmania promastigotes into infectious amastigotes has been reported to be accompanied by differential tubulin gene expression. In this study, alpha-tubulin expression under various stages of differentiation was measured in an in vitro generated arsenite-resistant L. donovani strain. While levels of expression of alpha-tubulin were similar in wild type and resistant promastigotes, during conversion into axenic amastigotes the changes in the expression levels of alpha-tubulin varied widely between the two strains. Sensitivity of the two strains to paclitaxel (known to promote tubulin assembly) differed, with the resistant strain being two-fold more sensitive than the wild type strain. Paclitaxel was also seen to cause differential effects on alpha-tubulin levels in the two strains.

Effect of vanillin on methylene blue plus light-induced single-strand breaks in plasmid pBR322 DNA

The ability of vanillin (4-hydroxy-3-methoxybenzaldehyde), a naturally occurring food flavouring agent, in inhibiting photosensitization-induced single-strand breaks (ssbs) in plasmid pBR322 DNA has been examined in an in vitro system, independent of DNA repair/replication processes. Photosensitization of DNA with methylene blue, visible light and oxygen, induced ssbs resulting in the production of open circular form (OC form) in a concentration-dependent manner. The yield of OC form induced by photosensitization was increased several-fold by deuteration of the buffer and was found to be inhibited by sodium azide, a scavenger of singlet oxygen (1O(2)). Vanillin, per se, did not induce but inhibited photosensitization-induced ssbs in plasmid DNA, at millimolar concentrations. The inhibitory effect of vanillin was both concentration- and time-dependent. On a molar basis, vanillin was, however, less effective than trolox, a water-soluble analogue of alpha-tocopherol. Photosensitization by methylene blue system generates singlet oxygen, as one of the major components of ROS. Therefore, interaction of singlet oxygen with vanillin was investigated. The rate constant of vanillin with 1O(2) was estimated to be 5.93x10(7)M(-1)s(-1) and that of sodium azide as 2. 7x10(8)M(-1)s(-1). The present investigations show that vanillin can protect against photosensitization-induced ssbs in the plasmid pBR322 DNA, and this effect may partly be due to its ability to scavenge 1O(2).

Supracricoid laryngectomy with Cricohyoidopexy--a clinico oncological & functional experience

Supracricoid laryngectomy with Cricohyoidopexy (CHP) is a procedure that is commonly practiced in France & Canada. Eight such procedures were carried out at Kidwai Memorial Institute of Oncology, Bangalore during the period from 1991 through 1996. Four Glottic, 3 transglottic & one supraglottic cancers were subjected to this procedure. The study comprised of 7 males & 1 female. The average age was 52 years. Two procedures were done as salvage procedures for radiotherapy (RT) failures. The patients have a follow-up ranging from one year to six years, except for one who died soon after discharge from hospital secondary to myocardial infarction. Median follow up was four years. The three year acturial disease free survival was 83%. Six out of 8 (75%) were decannulated, and physiologic deglutition without aspiration was established in all patients. Hospital stay ranged from 11 to 62 days averaging 29 days. The speech was analyzed together with other partial laryngectomies and was found to be qualitatively worse than speech after other partial laryngectomy procedures. In addition speech intensity levels after CHP were lower than in other partial laryngectomy procedures. The speech however allowed normal social interaction. This procedure certainly has distinct oncological advantage in encompassing circumferential horse-shoe lesions with minimal subglottic extension which in the past would have received total laryngectomy and needs to be included in the repertoire of speech restorative surgery in laryngeal cancers.