Dodecanoic acid & palmitic acid disarms rifampicin resistance by putatively targeting mycobacterial efflux pump Rv1218c

Background & objectives

Drug-resistant tuberculosis (TB) jeopardizes the treatment process with poor outcomes. Efflux pumps (EPs) belonging to the ABC transporter family in Mycobacterium tuberculosis confer resistance to rifampicin (RMP) besides genetic mutations thus serving as a target for a potential adjunct therapeutic inhibitory molecule. Rv1218c is one such pump that was previously reported to be active in multidrug-resistant TB clinical isolates.

Methods

In this study, the inhibition potential of Rv1218c-EP was tested on 8 molecules that were shortlisted by in silico methods. These molecules were subjected to the minimum inhibitory concentration (MIC) determination, checkerboard drug combination assay, ethidium bromide-DNA binding assay, and in vitro and ex vivo cytotoxicity assay.

Results

Based on the outcome of the study, two molecules dodecanoic acid (DA) and palmitic acid (PA) were found to be potential enough to decrease the MIC of RMP by 8 to 1000 folds against multidrug-resistant clinical isolates and Rv1218c expressing recombinant Mycobacterium smegmatis.

Interpretation & conclusions

These molecules were also found to reduce the time taken by RMP to kill these drug-resistant Mycobacteria to 48 h, unlike control isolates that survived more than 240 h of RMP exposure. The functional concentration of both molecules was non-toxic to the epithelial and blood mononuclear cells. With further comprehensive scientific validation, PA and DA could be recommended as adjunct therapeutic molecules with first-line anti-TB drugs to treat drug-resistant TB.

Changes in mitral regurgitation following acute myocardial infarction: early and long-term follow-up

Background

Mitral regurgitation (MR) is commonly observed following acute myocardial infarction (MI). Localised left ventricular (LV) remodelling in the region of papillary muscles together with impaired myocardial contractility promote MR. There is a paucity of long-term follow-up studies to determine whether the severity of MR observed post-MI, changes with time.

Purpose

This study retrospectively followed up patients with MR detected following acute MI (AMI) to investigate changes in MR severity with time and assess for pre-discharge predictors of MR regression or progression.

Methods

Clinical records of 1000 patients admitted with AMI between 2016 and 2017 to a single centre were retrospectively interrogated. One hundred and nine patients met the inclusion criteria of MR on pre-discharge transthoracic echocardiography (TTE) and follow-up TTE scans. Echocardiographic parameters were investigated to determine predictors of progression or regression at follow-up. Patients were divided according to those who had early follow-up TTE (within 1-year) and late follow-up TTE (beyond 1-year).

Results

Early follow-up TTE was performed in 73 patients at a median of 6 (IQR 3–9) months. Patients had a mean age of 69±13 years and were predominantly male 50/73 (68%). At baseline, relative MR severities were: 49/73 (67%) mild MR, 23/73 (32%) moderate MR and 1 (1%) severe MR. At follow-up, MR had completely resolved in 18/73 (23%) patients, while 39/73 (53%) had mild MR, 15/73 (21%) moderate MR and 1 (1%) severe MR. Compared to patients with no resolution of MR, those with completel resolution were younger (mean age 62±16 vs 72±11 years; p=0.015) but there were no other significant differences between the groups. Resolution at early follow-up did not significantly influence long-term mortality rates. Late follow-up TTE was performed in 69 patients at a median 2.4 (IQR 2–3.2) years. Pre-discharge, 49/69 (71%) patients had mild MR and 20/69 (29%) moderate MR. At follow-up, MR had completely resolved in 18/69 (26%), and amongst patients with persistent MR, proportion of severities were: 37/69 (54%) mild MR, 11/69 (16%) moderate MR and 3/69 (4%) severe MR. Patients with progression of mild MR were more likely to have lower left ventricular ejection fraction (LVEF: 47±15 vs 57±12%; p=0.010) and greater indexed left ventricular end-systolic volume (LVESVi: 37±23 vs 25±14 ml/m2; p<0.001) on pre-discharge TTE. Resolution of MR at late follow-up was associated with a reduction in long-term mortality [deaths: 2/55 (3%) vs 3/14 (21%); p=0.022] at a mean follow-up of 4.2 years from MI.

Conclusion

MR observed following AMI completely resolved in approximately one-quarter of patients at 6-month and 2-year follow-up. Progression of mild MR at long-term follow-up appears to be associated with increased mortality and is predicted by lower LVEF and greater LVESVi pre-discharge.

Funding Acknowledgement

Type of funding sources: None.

Tumescent Local Anesthesia in Parotid Abscess - Novel Application of Old Technique

Tumescent local anesthesia (TLA) is a regional anesthetic technique in which the diluted local anesthetic drug (commonly lidocaine) and epinephrine solution in large volume is injected subcutaneously around the site of incision. The main advantages of TLA are excellent bloodless field and longer duration of analgesia because of addition of epinephrine. Although TLA was used in various surgical procedures, there is no literature to date that has reported its use in the parotid region. Hence, we present an interesting case where this old technique found a novel application in avoiding general anesthesia and its sequelae. We also believe that it provides valuable information to doctors of various categories such as surgeons, Anesthesiologists and general practitioners/family physicians.

Left ventricular function and clinical heart failure after myocardial infarction revascularized with percutaneous coronary intervention - comparison between STEMI and NSTEMI in modern practice

Funding Acknowledgements

Type of funding sources: None.

Introduction

Left ventricular systolic dysfunction (LVSD) is a common consequence of myocardial infarction (MI). Data from historic series identified LVSD in up to 60% of patients post-MI. However, in modern practice, with high-sensitivity cardiac biomarkers leading to early detection of MI and widespread use of early revascularization, the prevalence of LVSD in the acute phase of MI and its impact on subsequent clinical heart failure remains unknown.

Purpose

To ascertain the prevalence of LVSD on pre-discharge echocardiography and its impact on subsequent clinical heart failure after type 1 MI treated with percutaneous coronary intervention (PCI) in a UK tertiary cardiac centre.

Methods

A retrospective electronic patient records review of consecutive patients with type 1 MI treated with PCI between January 2016 - December 2017. Patients treated conservatively or with surgical revascularization were excluded.

Results

1000 consecutive patients were identified and 948/1000 who had an inpatient echocardiogram prior to discharge were included in this analysis – 413 ST elevation MI (STEMI) and 535 non-ST elevation (NSTEMI). Median door to balloon time for STEMI was 42 minutes (IQR 28-79). Median time from symptom onset to intervention for NSTEMI was 3 days (IQR 1-6). LVSD was defined as left ventricular ejection fraction (LVEF) <50% on transthoracic echocardiogram carried out during the hospital episode. LVSD was significantly more prevalent in patients with STEMI compared to NSTEMI (37.4% vs 17.3%, p < 0.001). Median LVEF was significantly lower in the STEMI population (55%, IQR 45-60) compared to patients with NSTEMI (60%, IQR 54-65), p < 0.001. However, rates of clinical heart failure at index presentation with MI did not vary significantly between STEMI and NSTEMI patients (6.1% vs 4.9%, p = 0.414). In stepwise multivariate regression models: age, peak troponin and previous coronary artery bypass grafting were predictors of LVEF, whereas LVEF and previous MI were predictors of clinical heart failure

Patients with LVSD on pre-discharge echocardiography had significantly higher rates of 30-day readmission with heart failure (2.9% vs 0.7%, p = 0.017), 30-day all-cause mortality (6.1% vs 2%, p = 0.001), 30-day cardiac mortality (5.7% vs 1%, p < 0.001) and 2-year all-cause mortality (5.7% vs 1.6%, p = 0.001). However, at 2-years, there was no difference in hospital readmission with heart failure (0.8% vs 0.3%, p = 0.276). There were no significant differences between STEMI and NSTEMI patients for these endpoints.

Conclusions

Early revascularisation with PCI has led to a reduction in the prevalence of early LVSD post-MI compared to historical data. However, the presence of LVSD remains a powerful predictor of adverse clinical outcomes. Despite lower rates of LVSD on pre-discharge echocardiography in patients with NSTEMI compared with STEMI, the incidence of subsequent clinical heart failure is similar. This however may be underestimated due to survival bias.

Anaemia and coronary microvascular dysfunction in end-stage renal disease

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): (1) University Hospitals Birmingham Charity (2) Metchley Park Medical Society

Introduction

 

Coronary microvascular dysfunction (CMD) is common among patients with end-stage renal disease (ESRD) and confers poor prognosis. Coronary flow velocity reserve (CFVR) is a marker of coronary microvascular function and can be reliably measured using Doppler echocardiography. Reduced CFVR in ESRD has been attributed to factors such as hypertension and left ventricular hypertrophy (LVH). Anaemia is prevalent in ESRD but the association between haemoglobin and CFVR in ESRD has not been studied. 

Purpose

 

To assess if CFVR is related to haemoglobin among patients with ESRD. 

Methods

 

22 subjects with ESRD and awaiting kidney transplant (8 pre-dialysis and 14 on peritoneal dialysis) were studied with adenosine myocardial contrast echocardiography, Doppler CFVR assessment and serum multiplex immunoassay analysis. Individuals with diabetes, uncontrolled hypertension or ischaemic heart disease were excluded.

Results 

7/22 (32%) of subjects had CMD (defined as CFVR <2). Age (47 years ± 15 vs 55 ± 10, p = 0.177), estimated glomerular filtration rate [7ml/min/1.73m² (5-11) vs 9 (7-10), p = 0.837], systolic blood pressure (129mmHg ± 25 vs 137 ± 20, p = 0.398) and left ventricular mass index (98g/m² ± 31 vs 98 ± 28, p = 0.936) did not significantly differ between subjects with or without CMD. There were no significant differences in other demographic, haemodynamic, laboratory or echocardiographic variables between the two groups.  A panel of biomarkers of inflammation, myocardial stretch, cardiac fibrosis and LVH studied by multiplex immunoassay also did not show any significant differences between the two groups. No subjects had wall motion abnormalities or perfusion defects on myocardial contrast echocardiography.

CFVR was significantly lower in subjects with CMD (1.6 ± 0.2 vs 3.2 ± 0.9, p < 0.001). Subjects with CMD had significantly lower haemoglobin than subjects without CMD (102g/L ± 12 vs 117g/L ± 11, p = 0.008). There was a moderate positive correlation between haemoglobin and CFVR (r = 0.65, p = 0.001) – figure 1. In a stepwise multiple regression model with CFVR as the dependent variable and age, haemoglobin, systolic blood pressure, left ventricular mass index and estimated glomerular filtration rate as independent variables, only haemoglobin was an independent predictor of CFVR (β=0.051 95%CI 0.023-0.079, p = 0.001). 

Conclusions 

Among our cohort of ESRD patients awaiting kidney transplant, there was a high prevalence of CMD despite well controlled blood pressure and no significant LVH. Subjects with CMD had significantly lower haemoglobin than subjects without CMD. Reduced haemoglobin causes impaired oxygen carrying capacity to the myocardium, which may lead to microvascular ischaemia and adverse microvascular remodelling, causing CMD. Thus, anaemia may be a potentially correctible driver of CMD in ESRD.  This association needs to be confirmed in larger studies.

Abstract Figure 1

Ischaemic mitral regurgitation: incidence, clinical and angiographic characteristics of 1000 patients with type 1 myocardial infarction undergoing percutaneous coronary intervention

Background

Previous studies of the incidence and severity of mitral regurgitation (MR) following acute myocardial infarction (MI) were limited by the study population (ST-elevation MI only), by diagnostic methods (lack of multiparametric quantification), or by the time-frame of study (late assessment post-MI). The true incidence of ischaemic MR (IMR) immediately following type 1 MI [non-ST-elevation (NSTEMI) and ST-elevation (STEMI)] patients in the modern era of universal early revascularisation remains unclear. Since even mild IMR confers a poor prognosis, factors which promote or protect against the development of MR require further evaluation.

Purpose

To determine the incidence, clinical and angiographic characteristics of patients with IMR following type 1 MI treated with PCI.

Methods

This was a single-centre study of 1000 consecutive, prospectively recruited patients admitted to the Queen Elizabeth Hospital Birmingham with type 1 MI who underwent PCI. Early inpatient transthoracic echocardiography (TTE) was performed by accredited echocardiographers using standard multiparametric quantification.

Results

MR was observed in 294/1000 patients (29.4%) post-MI, graded as mild (76%), moderate (21%) and severe (3%). Median time from symptom onset to PCI was 1 day (IQR 0–4) and to TTE 2 days (IQR 1–3).

Compared to patients without MR (MR-), those with MR (MR+) were older (73±12 years vs 66±13 years; p<0.001), male (75% vs 64%; p<0.001) and more likely to have a history of hypertension (HTN) (63% vs 55%; p=0.0117), heart failure (HF) (3.4% vs 1.1%; p=0.0140) and previous MI (28% vs 20%; p<0.005). MR+ patients more frequently presented with HF (8.5% vs 4.2%; p=0.0075), lower LV ejection fraction (LVEF) (50±14% vs 55±11%; p<0.001) and higher peak high sensitivity troponin T (765ng/L, IQR 170–3032 vs 400ng/L, IQR 51–1966; p<0.0001).

MR+ patients were more likely to have severe disease in the left circumflex (LCx) (50% vs 33%; p<0.0001) or right coronary artery (RCA) (51% vs 43%; p=0.0135). Incidence of severe disease in the left main stem and left anterior descending artery (LAD) did not significantly differ between the two groups.

Incidence of MR was equal (29%) amongst STEMI (126/431) and NSTEMI (168/569) patients. While the time to revascularisation did not affect the prevalence of MR following STEMI (linear regression analysis of door-to-balloon time in MR+ and MR- patients p=0.843), NSTEMI patients were more likely to develop MR if revascularisation was delayed (linear regression analysis of symptom onset to PCI time MR+ vs MR- p=0.061).

Conclusion

Almost 1/3 of patients with type 1 MI undergoing revascularisation have MR evident on pre-discharge TTE. Factors promoting MR include older age, male sex, HTN, HF, larger non-LAD territory infarct, and depressed LVEF. The incidence of MR following STEMIs and NSTEMIs is equal. Earlier revascularisation is unlikely to reduce MR in STEMI patients but may improve MR prevalence following NSTEMI.

Funding Acknowledgement

Type of funding source: None

Risk stratification on echocardiography and outcome in ischaemic mitral regurgitation

Background

Ischaemic mitral regurgitation (IMR) confers a poor prognosis. Transcatheter intervention may improve survival but benefit is likely to depend on severity of IMR relative to LV remodelling following myocardial infarction (MI). In theory, those with “discordant” IMR (significant regurgitant volume without severe LV dilatation or impairment), are expected to benefit most from mitral intervention. While subcategorization may help to inform treatment, there are no data on post-MI patients in this respect.

Purpose

To determine the incidence of discordant & concordant IMR categorised on echocardiography post-MI and impact on outcomes.

Methods

1000 consecutive patients admitted to our hospital with myocardial infarction who underwent coronary angioplasty were included. Early inpatient TTE was performed by accredited echocardiographers using standard multiparametric quantification.

Using TTE parameters, 4 subgroups were identified (figure) according to the degree of MR relative to LV remodelling. Thresholds were based on European guidelines (± 2SD from normal) and median value among survivors for vena contracta (VC):

– LVEF: 52% (♂), 54% (♀)

– Indexed LV end diastolic volume (LVEDVi): 74ml/m2 (♂), 61ml/m2 (♀)

– Effective regurgitant orifice area (EROA) ≥0.2cm2

– Regurgitant volume (RVol) ≥30ml

– VC ≥0.5cm

Results

MR was seen in 294/1000 patients (29.4%) with a severity of mild (76%), moderate (21%) and severe (3%). Concordant and discordant IMR were each seen in 16/294 (5%) of IMR patients post-MI.

After a mean follow up of 3.2 years, IMR patients had a 3% rate of heart failure (HF) within 1 year and 19% mortality. Non-survivors had significantly worse IMR (PISA 0.65±0.25cm vs 0.54±0.19cm; p=0.033; VC 0.63±0.25cm vs 0.49±0.18cm; p=0.014), worse LV function (LVEF 44±17% vs 51±13%; p<0.001), larger LV (LVEDVi 67±23ml/m2 vs 60±22ml/m2; p=0.032) and larger indexed LA volume (LAVi) (44±22ml vs 35±15ml; p<0.001). Those with concordant IMR had the worst survival (50%) although almost 1 in 5 of those with discordant MR died within the follow up period (19%). Using multivariable Cox regression, significant predictors of mortality included LVEF (p<0.001; HR 0.96, 0.94–0.98) and LAVi (p<0.001; HR 1.02, 1.01–1.03) but not LVEDVi.

Conclusion

1) Significant predictors of mortality in IMR include LA dilatation and decline in LVEF, but not LV dilatation.

2) Although discordant severe IMR is uncommon following MI, mortality if left untreated remains high. Attention should be paid to early selection of this cohort for intervention.

Funding Acknowledgement

Type of funding source: None

Workplace based Potentially Malignant Oral Lesions Screening among Tobacco Consuming Migrant Construction Site Workers in Chennai, South India: A Pilot Study

Context:

Vulnerable population groups such as migrant workers are identified as emerging high-risk groups for oral cancer owing to the high prevalence of smokeless tobacco consumption. Premature deaths due to oral cancer can be prevented by screening the population with high tobacco consumption practices and detecting early reversible stages of oral mucosal cavity lesions and facilitating linkages for further care.

Aim:

To assess prevalence of potentially malignant oral mucosal cavity lesions among tobacco consuming migrant construction workers in sub-urban Chennai, India.

Settings and Designs:

A workplace based cross-sectional study design.

Materials and Methods:

A cross-sectional study was conducted at workplaces i.e., construction sites for screening potentially malignant oral mucosal cavity lesions among migrant workers across 23 construction sites of Chennai during September 2019 - February 2020. An onsite, group health education session was provided about the harms of tobacco use to the migrants.

Statistical Analysis Used:

Data entered in MS Excel was analysed using SPSS and multivariate analysis was performed.

Results:

Among 640 migrants included in the study, 411 (64.2%) were less than 30 years of age, 623 (97.4%) were from north-eastern states of India such as West Bengal, Bihar, Rajasthan, Uttar Pradesh, Jharkhand. A considerable size (272, 42.5%) could not read or write and 355 (55.4%) earn a monthly income of less than ten thousand rupees. Current tobacco users were 619 (96.7%), smokeless tobacco users (463, 72.34%), smokers (206, 32.2%) and dual users (52,8.12%). Inflammatory mucosal lesions in the oral cavity were 70.97% and more among smokeless tobacco users comparable to 22.58% among tobacco smokers and was significantly associated with up to 20 years of tobacco consumption.

Conclusions:

Prevalence of Potentially malignant oral lesions among smokeless tobacco using interstate migrant construction site workers is very high and need urgent interventions.

Self-care practices among type II diabetics in rural area of Kancheepuram district, Tamil Nadu

Introduction:

Type 2 diabetes mellitus is one of the most prevalent noncommunicable diseases in India. The acute and chronic complications of diabetes impact the physical, mental, and social well-being of the patients, thereby, placing a major burden on the health care system. Studies have shown that adequate self-care practices among the patients will facilitate good glycemic control and prevent complications.

Objectives:

To study the patterns of self-care practice among diabetic patients and the factors associated with them.

Methods:

This descriptive cross-sectional study was carried out among 250 diabetics in the rural field practice area of a Tertiary Medical College and Hospital in Chennai. The participants were interviewed on their diabetic status and various components of self-care practices adopted from The Summary of Diabetes Self-care Activities (SDSCA) Measure. Adherence to medication was assessed by using Morisky Medication Adherence Scale-4 (MMAS-4).

Results:

Our study observed that the overall prevalence of good self-care practices was very low (5.6%). Moderate self-care practices were prevalent in 42% of the study participants whereas the majority (52.4%) of the study population had poor self-care practices. In our study, the association between self-care activity with educational status and occupation was found to be statistically significant. Adherence was high for blood sugar testing (75.2%) and medication (70.4%) in the study population whereas adherence for foot care was poor (17.6%).

Conclusion:

Our study emphasized on the need for knowledge and awareness to be provided in rural areas regarding diabetes care management and self-care practices. Structured programs need to be planned to improve the attitude and practices of diabetic patients to promote better compliance towards diet, exercise, adherence to drugs, and appropriate foot care.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Dynamic Search Engine Platform for Cloud Service Level Agreements Using Semantic Annotation

This article describes how cloud applications are negotiated, deployed, monitored, evaluated and terminated through the service level agreements (SLA). The service definition & their objectives, performance measures, pricing, roles of the involved parties are stated as part of the SLA. Searching for SLA templates from the provider's place is considered as a cumbersome process for the consumer. Also, it is not guaranteed that retrieved SLAs always match with the consumer requirements. Hence, semantic search engine platforms for cloud SLA using a novel architecture are introduced here. SLA agreements are crawled from the web and annotation is performed in the agreement terms using SLA ontologies to fasten and improve the accuracy of the search process. In the proposed architecture, 3 ontologies are developed for SaaS, PaaS and IaaS as well as 140 SLA documents are gathered. Results revealed that the search efficacy is almost 90% in finding the desired SLA for the consumer to ease negotiation. Moreover, the performance is compared with similar search engine GoNTogle, and it was observed that proposed model produced good results.

Impact of obstructive sleep apnea on neurological recovery after ischemic stroke: A prospective study

OBJECTIVES

The presence of obstructive sleep apnea (OSA) has been found to adversely affect the neurological recovery after acute ischemic stroke (AIS) in previous observational studies. However, in most of these studies, diagnosis of OSA was based on oximetry data alone, raising concern in the accuracy of diagnosis as well as estimation of severity. Purpose of our study was to determine the prevalence and severity of OSA (based on polysomnography and American Association of Sleep Medicine [AASM] criteria) in patients with AIS and to compare the post-stroke neurological and functional outcome, in those with and without OSA.

MATERIALS AND METHODS

A prospective single-centre study was conducted over a period of eighteen months from January 2013. The demographic and clinical data were collected, and the etiology of stroke was classified according to TOAST classification. Subsequently, all selected patients (N=99) underwent premorbid sleep status assessment by Epworth Sleepiness Scale followed by polysomnography using Resmed ApneaLink polysomnograph. Data were analyzed to find out the prevalence and severity of OSA as well as its impact on neurological recovery as assessed by National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) at different time points, starting from admission.

RESULTS

There was a high prevalence of OSA (~60%) with a quarter of them having severe OSA. The OSA group had a significantly higher mean NIHSS score at discharge (P=.002) and significantly higher mRS score (irrespective of severity of OSA) at all points of evaluation.

CONCLUSION

Ischemic stroke patients with OSA tend to have poor neurological and functional recovery, across all segments of stroke and OSA severity.

Comparison of two different doses dexmedetomidine as an adjuvant to bupivacaine in sub-arachnoid block for abdominal hysterectomies. A randomized double blinded study

Background: Abdominal hysterectomy is often a long duration procedure and warrants intense pain relief in the post-operative period. Dexmedetomidine when added to bupivacaine in subarachnoid block prolongs the duration of surgical anaesthesia, decreases blood loss and prolongs duration of post-operative pain relief. Aims and Objective: To compare two different doses dexmedetomidine as an adjuvant to bupivacaine in sub-arachnoid block in abdominal hysterectomy surgeries. Materials and Methods: 60 patients of age group 30-60 years posted for elective abdominal hysterectomies under American Society of Anaesthesiologists (ASA) physical classification I or II were randomly allocated into 2 groups of 30 each. Group A received 5 micrograms (μg) of dexmedetomidine along with 3.5 ml of 0.5% bupivacaine in sub-arachnoid block. Group B received 10 μg of dexmedetomidine along with 3.5 ml of 0.5% bupivacaine in sub-arachnoid block. Changes in blood pressure, heart rate, respiratory rate, oxygen saturation, ephedrine consumption, blood loss, duration of sensory block, duration of motor block, duration of analgesia were compared between two groups. Results: There was no significant difference in change in heart rate, respiratory rate, oxygen saturation, duration of sensory block, duration of motor block between two groups. Patients in group B had significant decrease in blood pressure, blood loss and significant increase in ephedrine consumption compared to Group A. The duration of analgesia was also prolonged in group B compared to Group A. Conclusion: Dexmedetomidine in dose of 10 μg is a better adjuvant to bupivacaine for abdominal hysterectomy surgeries.Asian Journal of Medical Sciences Vol.8(2) 2017 59-63

Urethral Stenting for Obstructive Uropathy Utilizing Digital Radiography for Guidance: Feasibility and Clinical Outcome in 26 Dogs

Background

Urethral stent placement is an interventional treatment option to alleviate urethral outflow obstruction. It has been described utilizing fluoroscopy, but fluoroscopy is not as readily available in private practice as digital radiography.

Objectives

To describe the use of digital radiography for urethral stent placement in dogs with obstructive uropathy.

Animals

Twenty‐six client‐owned dogs presented for dysuria associated with benign and malignant causes of obstructive uropathy that underwent urethral stent placement.

Methods

Retrospective study.

Results

Causes of obstructive uropathy included transitional cell carcinoma, prostatic carcinoma, hemangiosarcoma, obstructive proliferative urethritis, compressive vaginal leiomyosarcoma, and detrusor‐sphincter dyssynergia. Survival time range was 1–48 months (median, 5 months). All dogs were discharged from the hospital with urine outflow restored. Intraprocedural complications included guide wire penetration of the urethral wall in 1 dog and improper stent placement in a second dog. Both complications were successfully managed at the time of the procedure with no follow‐up problems noted in either patient.

Conclusion and Clinical Importance

Urethral stent placement can be successfully performed utilizing digital radiography. The complications experienced can be avoided by more cautious progression with each step through the procedure and serial radiography. The application of digital radiography may allow treatment of urethral obstruction to become more readily available.

A Potential Biomarker in Amyotrophic Lateral Sclerosis: Can Assessment of Brain Iron Deposition with SWI and Corticospinal Tract Degeneration with DTI Help?

BACKGROUND AND PURPOSE

Iron-mediated oxidative stress plays a pivotal role in the pathogenesis of amyotrophic lateral sclerosis. This study aimed to assess iron deposition qualitatively and quantitatively by using SWI and microstructural changes in the corticospinal tract by using DTI in patients with amyotrophic lateral sclerosis.

MATERIALS AND METHODS

Seventeen patients with amyotrophic lateral sclerosis and 15 age- and sex-matched controls underwent brain MR imaging with SWI and DTI. SWI was analyzed for both signal-intensity scoring and quantitative estimation of iron deposition in the anterior and posterior banks of the motor and sensory cortices and deep gray nuclei. The diffusion measurements along the corticospinal tract at the level of pons and medulla were obtained by ROI analysis.

RESULTS

Patients with amyotrophic lateral sclerosis showed reduced signal-intensity grades in the posterior bank of the motor cortex bilaterally. Quantitative analysis confirmed significantly higher iron content in the posterior bank of the motor cortex in patients with amyotrophic lateral sclerosis. In contrast, no significant differences were noted for the anterior bank of the motor cortex, anterior and posterior banks of the sensory cortex, and deep nuclei. Receiver operating characteristic comparison showed a cutoff of 35μg Fe/g of tissue with an area under the curve of 0.78 (P = .008) for the posterior bank of the motor cortex in discriminating patients with amyotrophic lateral sclerosis from controls. Fractional anisotropy was lower in the pyramidal tracts of patients with amyotrophic lateral sclerosis at the pons and medulla on either side, along with higher directionally averaged mean diffusivity values. The combination of SWI and DTI revealed an area under the curve of 0.784 for differentiating patients with amyotrophic lateral sclerosis from controls.

CONCLUSIONS

Measurements of motor cortex iron deposition and diffusion tensor parameters of the corticospinal tract may be useful biomarkers for the diagnosis of clinically suspected amyotrophic lateral sclerosis.

A comparative histopathological study of systemic candidiasis in association with experimentally induced breast cancer

Systemic candidiasis is a fungal infection which coupled with solid malignancies places patients at high risk of succumbing to the disease. Few studies have shown evidence of the relationship between systemic candidiasis and malignancy-induced immunosuppression disease especially in breast cancer. At present, animal studies that exclusively demonstrate this relationship have yet to be conducted. The exact causative mechanism of systemic candidiasis is currently under much speculation. This study therefore aimed to demonstrate this relationship by observing the histopathological changes of organs harvested from female Balb/c mice which were experimentally induced with breast cancer and inoculated with systemic candidiasis. The mice were randomly assigned to five different groups (n=12). The first group (group 1) was injected with phosphate buffer solution, the second (group 2) with systemic candidiasis, the third (group 3) with breast cancer and the final two groups (groups 4 and 5) had both candidiasis and breast cancer at two different doses of candidiasis, respectively. Inoculation of mice with systemic candidiasis was performed by an intravenous injection of Candida albicans via the tail vein following successful culture methods. Induction of mice with breast cancer occurred via injection of 4T1 cancer cells at the right axillary mammary fatpad after effective culture methods. The prepared slides with organ tissues were stained with hematoxylin and eosin, periodic acidic schiff and gomori methenamine silver stains for a histopathological analysis. Grading of primary tumour and identification of metastatic deposits, as well as scoring of inflammation and congestion in all the respective organs was conducted. Statistical tests performed to compare groups 2 and 4 showed that group 4 exhibited a highly statistically significant increase in organ inflammation and congestion (p<0.01). The median severity of candidiasis in the kidneys and liver also increased in group 4 as compared to group 2. In conclusion, based on the above evidence, systemic candidiasis significantly increased in mice with breast cancer.

Progression of a solitary, malignant cutaneous plasma-cell tumour to multiple myeloma in a cat

An 11-year-old male domestic shorthair cat was examined because of a soft-tissue mass on the left tarsus previously diagnosed as a malignant extramedullary plasmacytoma. Findings of further diagnostic tests carried out to evaluate the patient for multiple myeloma were negative. Five months later, the cat developed clinical evidence of multiple myeloma based on positive Bence Jones proteinuria, monoclonal gammopathy and circulating atypical plasma cells. This case represents an unusual presentation for this disease and documents progression of an extramedullary plasmacytoma to multiple myeloma in the cat.

Docetaxel and oxaliplatin as first-line therapy for advanced non-small cell lung cancer: a phase II trial

We sought to evaluate the safety and efficacy of docetaxel and oxaliplatin combination as first-line therapy for patients with stage IV or wet III(B )non small cell lung cancer. Patients received oxaliplatin at 85 mg/m(2) intravenously over 2 hours on days 1 and 15 along with docetaxel at 30 mg/m(2) intravenously on days 1 and 8; both given every 28 days. Cycles were repeated every 4 weeks for a maximum of 6. Fifteen patients were enrolled for an overall response rate of 50% (95% CI 21-74%). Median progression-free survival was 2.4 months with a 1-year progression free survival of 10%. Median overall survival was 7.9 months with 49% of patients alive at 1 year. Most common toxicities were nausea, vomiting, and dehydration. This combination has notable activity in advanced non-small cell lung cancer with a favorable toxicity profile.

A profile of bacteriologically confirmed pulmonary tuberculosis in children

OBJECTIVE

To describe the clinical profile of children with bacteriologically confirmed tuberculosis.

STUDY DESIGN

A multicentric study was conducted in three hospitals in Chennai city between July 1995 and December 1997. Children aged 6 months to 12 years with signs and symptoms suggestive of tuberculosis were investigated further. Clinical examination, chest radiograph, tuberculin skin test with 1 TU PPD and, sputum or gastric lavage for mycobacterial smear and culture were done for all and, lymph node biopsy when necessary.

RESULTS

A total of 2652 children were registered and tuberculosis was bacteriologically confirmed in 201. Predominant symptoms were history of an insidious illness (49%), fever and cough (47%), loss of weight (41%) and a visible glandular swelling (49%). Respiratory signs were few and 62% were undernourished. Over half the patients with confirmed TB had normal chest X-ray. Abnormal X-ray findings included parenchymal opacities in 47% and hilar or mediastinal lymphadenopathy in 26%. The prevalence of isoniazid resistance was 12.6% and MDR TB 4%.

CONCLUSIONS

Children with tuberculosis present with fever and cough of insidious onset. Lymphadenopathy is a common feature even in children with pulmonary TB. A significant proportion of children have normal chest X-rays despite positive gastric aspirate cultures. Drug resistance rates in children mirror the pattern seen in adults in this geographic area.

Stoichiometry of cholesterol-sphingomyelin condensed complexes in monolayers

Some binary mixtures of cholesterol and phospholipids in monolayers have thermodynamic phase diagrams with two upper miscibility critical points. This feature has been interpreted in terms of 'condensed complexes' between the phospholipid and cholesterol. The present work gives evidence for the formation of complexes with a common simple integral stoichiometry in binary mixtures of cholesterol and a series of five sphingomyelins where the amide-linked acyl chain length is varied. This indicates that these complexes have a distinct geometry even though they form a liquid phase.

Condensed complexes, rafts, and the chemical activity of cholesterol in membranes

Epifluorescence microscopy studies of mixtures of phospholipids and cholesterol at the air-water interface often exhibit coexisting liquid phases. The properties of these liquids point to the formation of "condensed complexes" between cholesterol and certain phospholipids, such as sphingomyelin. It is found that monolayers that form complexes can incorporate a low concentration of a ganglioside G(M1). This glycolipid is visualized by using a fluorescently labeled B subunit of cholera toxin. Three coexisting liquid phases are found by using this probe together with a fluorescent phospholipid probe. The three liquid phases are identified as a phospholipid-rich phase, a cholesterol-rich phase, and a condensed complex-rich phase. The cholera toxin B labeled ganglioside G(M1) is found exclusively in the condensed complex-rich phase. Condensed complexes are likely present in animal cell membranes, where they should facilitate the formation of specialized domains such as rafts. Condensed complexes also have a major effect in determining the chemical activity of cholesterol. It is suggested that this chemical activity plays an essential role in the regulation of cholesterol biosynthesis. Gradients in the chemical activity of cholesterol should likewise govern the rates and direction of intracellular intermembrane cholesterol transport.

Chemical activity of cholesterol in membranes

Measurements are reported for the rate constants for the release of cholesterol (and dihydrocholesterol) to beta-cyclodextrin from mixtures with phospholipids in homogeneous monolayers at constant pressure at the air-water interface. In each mixture, it is found that the release rate shows a sharp decrease as the cholesterol concentration in the monolayer decreases through a composition corresponding to the stoichiometry of a cholesterol-phospholipid complex. The stoichiometry of the complex was established previously by the position of a sharp cusp in the thermodynamic phase diagram of each mixture and also by a minimum in average molecular area versus composition measurements. A theoretical model used earlier to account for the phase diagrams predicts the chemical potential and chemical activity of cholesterol in these mixtures. The calculated chemical activity also shows a sharp change at the complex stoichiometry in homogeneous monolayers. The similarities in change of observed release rate and calculated chemical activity are expected from reaction rate theory where the release rate is proportional to the cholesterol chemical activity. The chemical activity of cholesterol as determined by complex formation between some phospholipids and cholesterol in the plasma membrane of cells may serve a regulatory function with respect to intracellular cholesterol transport and biosynthesis.

Electric field effect on cholesterol-phospholipid complexes

Monolayer mixtures of dihydrocholesterol and phospholipids at the air-water interface are used to model membranes containing cholesterol and phospholipids. Specific, stoichiometric interactions between cholesterol and some but not all phospholipids have been proposed to lead to the formation of condensed complexes. It is reported here that an externally applied electric field of the appropriate sign can destabilize these complexes, resulting in their dissociation. This is demonstrated through the application of an electric field gradient that leads to phase separations in otherwise homogeneous monolayers. This is observed only when the monolayer composition is close to the stoichiometry of the complex. The electric field effect is analyzed with the same mean field thermodynamic model as that used previously to account for pairs of upper miscibility critical points in these mixtures. The concentrations of dihydrocholesterol, phospholipid, and complex vary strongly and sometimes discontinuously in the monolayer membrane in the field gradient. The model is an approximation to a two-dimensional liquid in which molecules freely exchange between free and complexed form so that the chemical potentials are constant throughout the membrane. The calculations are illustrated for a complex of about 15 molecules, composed of 5 cholesterol molecules and 10 phospholipid molecules.

Sero diagnosis of tuberculosis in children using two ELISA kits

The diagnosis of childhood tuberculosis is based on circumstantial evidence in the absence of a gold standard in the majority of cases. Sero-diagnosis offers scope for an early diagnosis in a variety of clinical conditions and is simple to perform. A number of mycobacterial antigens have been used for antibody detection assays and several are available as kits in the market. This study was done to evaluate the value of antibody detection kits (ELISA) against the A60 antigen and 38 kDa antigen of Mycobacterium tuberculosis in the diagnosis of childhood tuberculosis at the outpatient department of the Institute of Social Paediatrics, Government Stanley Hospital in collaboration with Tuberculosis Research Centre, Chennai. Thirty five children with pulmonary tuberculosis, 7 with TB lymphadenitis and 22 healthy controls were studied. In addition to routine investigations including gastric lavage for AFB culture, serum antibodies against the A60 and 38 kDa antigens were assayed using commercially available ELISA kits. With A60, IgM serum levels were positive in 74% of pulmonary TB cases, 57% of TB lymphadenitis cases and 50% of controls. A60 IgG was positive in 17% of pulmonary TB, 86% of TB lymphadenitis and 14% of controls. The 38 kDa IgG antibody was positive in 37% of pulmonary and 86% of TB lymphadenitis cases and 27% of controls. Among 10 culture confirmed cases, A60 IgM was positive in 8, A60 IgG in 3 and 38 kDa IgG in 5 patients. The sensitivity of the tests ranged between 29% and 71% and specificity between 50% and 86%. Although the numbers are small, the results suggest that serodiagnosis using the currently available antigens of M. tuberculosis is unlikely to be a confirmatory test for tuberculosis in children.

Condensed complexes of cholesterol and phospholipids

Mixtures of dihydrocholesterol and phospholipids form immiscible liquids in monolayer membranes at the air-water interface under specified conditions of temperature and 2-dimensional pressure. In recent work it has been discovered that a number of these mixtures exhibit two upper miscibility critical points. Pairs of upper critical points can be accounted for by a theoretical model that implies the cooperative formation of molecular complexes of dihydrocholesterol and phospholipid molecules. These complexes are calculated to be present in the membranes both above and below the critical points. Below the critical points the complexes form a separate phase, whereas above the critical points the complexes are completely miscible with the other lipid components. The cooperativity of complex formation prompts the use of the terminology condensed complex.

Ultra-high throughput rotary capillary array electrophoresis scanner for fluorescent DNA sequencing and analysis

We have constructed a rotary confocal fluorescence scanner and capillary array electrophoresis system that is designed to analyze over 1000 DNA sequencing or fragment sizing separations in parallel. Capillaries are arranged around the surface of a cylinder and a rotating objective in the middle of the cylinder excites and collects fluorescence from labeled DNA fragments as they pass the capillary detection window. The capillaries are pressure-filled with a replaceable matrix and the samples are electrokinetically injected in parallel from a stainless steel microtiter plate at the cathode end. We demonstrate that the instrument is capable of producing four-color data from all capillaries at a scan rate of 4 Hz (corresponding to a linear scan velocity of 121 cm/s). M13 sequencing data were obtained using a 128 capillary array mounted in half of the first quadrant of the scanner. In this initial run, read lengths greater than 500 bases were obtained in over 60% of the capillaries.

DNA sequencing using a four-color confocal fluorescence capillary array scanner

The design, construction and operation of a four-color capillary array electrophoresis scanner are presented. The use of sensitive energy transfer primers facilitates four-color detection of the DNA sequencing fragments following excitation at a single laser wavelength (488 nm). This scanner collects fluorescence data from up to 25 capillaries in parallel. The resulting four-color image files are automatically reduced to four-color line plots, and a base-calling program (Sax) is used to call the sequence. The performance of this system for DNA sequencing is demonstrated by examining twelve different motifs of the hypervariable region I of human mitochondrial (mt) DNA obtained from a Sierra Leone population.

Fluorometric assay of vasopressin and oxytocin: a general approach to the assay of peptides in tissues

A fluorometric method for the quantitative assay of vasopressin and oxytocin in individual rat pituitaries has been developed. Acid extracts of pituitaries are freed of amino acids and polyamines by passage over a copper-Sephadex column, and the peptides fraction is then labeled by reaction with fluorescamine. The resulting peptide fluorophors are separated by chromatography on a reverse-phase bonded column. Specificity of the procedure was ascertained by several criteria, including bioassay and amino-acid analysis of the eluted peptide fluorophors. The procedure serves as a model system for the assay of tissue peptides in the picomole range.