Comparative Analysis of Hemispherotomy in Adults versus Children- A Prospective Observational Series

BACKGROUND

Hemispherotomy (HS) is an effective treatment for unilateral hemispheric onset epilepsy. There are few publications for HS in adults, and there is no series comparing adults and pediatric patients of HS.

OBJECTIVE

To compare the hemispherotomies done in adult patients with pediatric ones in terms of efficacy and safety.

METHODS

Data was prospectively collected for HS patients (up to 18 years and more) from Aug 2014 to Aug 2018. Comparison between the groups was made for seizure onset, duration of epilepsy, frequency of seizures, number of drugs, intraoperative blood loss, postoperative seizure control, postoperative stay, postoperative motor functions, and preoperative and postoperative intelligence quotient. Follow-up was one year.

RESULTS

A total of 61 pediatric and 11 adults underwent HS. The seizure onset was earlier in children, and the duration of epilepsy was longer in adults. The frequency of seizures per day was more in children being 14.62 ± 26.34 in children, and 7.71 ± 5.21 per day in adults (P - 0.49). The mean number of drugs was similar in the preoperative and postoperative periods in both. Class I seizure outcome was similar in both the groups being 85.24% in children and 90.9% in adults (P - 0.56). Blood loss, postoperative stay, was similar in both the groups. No patient had a new permanent motor deficit. Power worsened transiently in 1 pediatric patient and in 4 adult patients. The visual word reading and object naming improved in both the groups (no intergroup difference), and IQ remained the same in both groups. One adult patient had meningitis, and another had hydrocephalus requiring shunt placement.

CONCLUSION

Hemispherotomy is a safe and effective procedure in adults as in children in appropriately selected patients.

Effectiveness of Yoga Intervention in Reducing Felt Stigma in Adults With Epilepsy: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Persons with epilepsy are afflicted with comorbidities such as stigma, anxiety, and depression which have a significant impact on their quality of life. These comorbidities remain largely unaddressed in resource-limited countries. This randomized controlled trial (RCT) aimed to investigate whether yoga and psychoeducation were effective in reducing felt stigma (primary outcome), neuropsychiatric outcomes, and seizure frequency, as compared with sham yoga and psychoeducation in persons with epilepsy.

METHODS

This was an assessor-blinded, sham yoga-controlled RCT. Patients clinically diagnosed with epilepsy, aged 18-60 years, and scoring higher than the cutoff score for felt stigma as measured by the Kilifi Stigma Scale (KSS) in our population were randomly assigned to receive either yoga therapy plus psychoeducation (intervention) or sham yoga therapy plus psychoeducation (comparator) for a duration of 3 months. The primary outcome was a significant decrease in felt stigma as compared with the comparator arm as measured by the KSS. Primary and secondary outcomes (seizure frequency, quality of life, anxiety, depression, mindfulness, trait rumination, cognitive impairment, emotion regulation) were assessed at baseline, 3 months, and 6 months. Parametric/nonparametric analysis of covariance and the χ2 test were used to compare the 2 arms.

RESULTS

A total of 160 patients were enrolled in the trial. At the end of the follow-up period (6 months), the intervention arm reported significant reduction in felt stigma as compared with the control arm (Cohen's d = 0.23, 95% CI -0.08 to 0.55, p = 0.006). Significantly higher odds of >50% seizure reduction (odds ratio [OR] 4.11, 95% CI 1.34-14.69, p = 0.01) and complete seizure remission (OR 7.4, 95% CI 1.75-55.89, p = 0.005) were also observed in the intervention group. The intervention group showed significant improvement in symptoms of anxiety, cognitive impairment, mindfulness, and quality of life relative to the control group at the end of follow-up period (p < 0.05).

DISCUSSION

Yoga can alleviate the burden of epilepsy and improve the overall quality of life in epilepsy by reducing perceived stigma.

TRIAL REGISTRATION INFORMATION

Clinical Trials Registry of India (CTRI/2017/04/008385).

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that yoga reduces felt stigma in adult patients with epilepsy.

Academic clinician frontline-worker wellbeing and resilience during the COVID-19 pandemic experience: Were there gender differences?

Prior research suggests COVID-19 has amplified stress on Academic Clinician Frontline-Workers (ACFW). The aim of this paper is: (1) to better understand the experiences of ACFW during the COVID-19 pandemic including their mental-emotional wellbeing, academic productivity, clinical experiences, and (2) to examine any gender differences. A cross-sectional survey was administered to University of Minnesota/M Health Fairview systems' faculty February-June 2021. Of the 291 respondents, 156 were clinicians, with 91 (58 %) identifying as Frontline-Workers (ACFW). Faculty wellbeing was assessed using validated measures in addition to measures of productivity and sociodemographics. For example, ACFW reported a higher Work-Family Conflict (WFC) scores compared to non-ACFW (26.5 vs. 24.1, p = 0.057) but did not report higher Family-Work Conflict (FWC) scores (17.7 vs. 16.3, p = 0.302). Gender sub-analyses, revealed that women ACFW compared to men ACFW reported higher WFC scores (27.7 vs. 24.1, p = 0.021) and FWC (19.3 vs. 14.3, p = 0.004). Academically, ACFW reported submitting fewer grants and anticipated delays in promotion and tenure due to the COVID-19 (p = 0.035). Results suggest COVID-19 has exacerbated ACFW stress and gender inequities. Reports of anticipated delay in promotion for ACFW may pose a challenge for the long-term academic success of ACFW, especially women ACFW. In addition, women may experience higher FWC and WFC as compared to men. Schools of academic medicine should consider re-evaluating promotion/tenure processes and creating resources to support women ACFW as well as ACFW caregivers.

VE-MMODE - A randomized controlled trial of Venlafaxine versus Escitalopram for treatment of mild to moderate depression in persons with epilepsy

OBJECTIVES

Depression in persons with epilepsy (PWE) goes undiagnosed and untreated. Despite being common, there are no direct efficacy comparisons of available antidepressants in PWE. Our aim was to compare the effectiveness of Venlafaxine (VEN) and Escitalopram (ESCIT) in comorbid depression in PWE.

METHODS

In a single-center, prospective, double-blinded randomized controlled trial (RCT) 90 PWE (age ≥18 years) with mild to moderate depression, were randomized in a 1:1 ratio to receive ESCIT (5-20 mg/day) or VEN (37.5-150 mg/day) for 8 weeks. The primary outcome was to study differences in the efficacy, based on the change in scores of the Hamilton depression rating scale (HAM-D) at 8 weeks. Seizure frequency, QOLIE-31, adverse event profile, and medication adherence were secondary outcome measures.

RESULTS

Using the NDDI-E scale, we screened 350 PWE, 90 were enrolled. ITT analysis included all participants and the PP analysis included 40 participants to VEN group and 42 to ESCIT group. Baseline mean (±SD) HAM-D scores for both groups were similar (13.53 ± 3.27; 13.02 ± 3.57). The mean difference (95%CI) on HAM-D scores at 8 weeks was found to be significant within both groups (ITT/PP- VEN: 7.75(6.75, 8.79)/7.92 (7.06, 8.78); p < 0.001, ESCIT: 8.21 (7.39, 9.03)/8.23(7.43, 9.04); p < 0.001). However, there was no significant difference in the efficacy of VEN versus ESCIT at 8 weeks. A significant improvement in QOLIE-31 index and seizure frequency was observed from baseline in both the groups. 90% of those on VEN and 92.9% of those using ESCITadhered to the treatment at week 8. Adverse events were more in VEN group than the ESCIT group.

CONCLUSIONS

This study found that HAMD scores improved significantly in the ESCIT and VEN groups, despite the fact that there was no clinically meaningful difference observed between the two groups. Trials with a larger sample size and longer duration are required to establish whether ESCIT or VEN is superior.

Excitatory cholinergic responses in mouse primary bronchial smooth muscle require both Ca2+ entry via l-type Ca2+ channels and store operated Ca2+ entry via Orai channels

Malfunctions in airway smooth muscle Ca²⁺-signalling leads to airway hyperresponsiveness in asthma and chronic obstructive pulmonary disease. Ca²⁺-release from intracellular stores is important in mediating agonist-induced contractions, but the role of influx via l-type Ca²⁺ channels is controversial. We re-examined roles of the sarcoplasmic reticulum Ca²⁺ store, refilling of this store via store-operated Ca²⁺ entry (SOCE) and l-type Ca²⁺ channel pathways on carbachol (CCh, 0.1-10 µM)-induced contractions of mouse bronchial rings and intracellular Ca²⁺ signals of mouse bronchial myocytes. In tension experiments, the ryanodine receptor (RyR) blocker dantrolene (100 µM) reduced CCh-responses at all concentrations, with greater effects on sustained rather than initial components of contraction. 2-Aminoethoxydiphenyl borate (2-APB, 100 μM), in the presence of dantrolene, abolished CCh-responses, suggesting the sarcoplasmic reticulum Ca²⁺ store is essential for contraction. The SOCE blocker GSK-7975A (10 µM) reduced CCh-contractions, with greater effects at higher (e.g. 3 and 10 µM) CCh concentrations. Nifedipine (1 µM), abolished remaining contractions in GSK-7975A (10 µM). A similar pattern was observed on intracellular Ca²⁺-responses to 0.3 µM CCh, where GSK-7975A (10 µM) substantially reduced Ca²⁺ transients induced by CCh, and nifedipine (1 µM) abolished remaining responses. When nifedipine (1 µM) was applied alone it had less effect, reducing tension responses at all CCh concentrations by 25% - 50%, with greater effects at lower (e.g. 0.1 and 0.3 µM) CCh concentrations. When nifedipine (1 µM) was examined on the intracellular Ca²⁺-response to 0.3 µM CCh, it only modestly reduced Ca²⁺ signals, while GSK-7975A (10 µM) abolished remaining responses. In conclusion, Ca²⁺-influx from both SOCE and l-type Ca²⁺ channels contribute to excitatory cholinergic responses in mouse bronchi. The contribution of l-type Ca²⁺ channels was especially pronounced at lower doses of CCh, or when SOCE was blocked. This suggests l-type Ca²⁺ channels might be a potential target for bronchoconstriction under certain circumstances.

Role of Gut Microbiota in Neurological Disorders and Its Therapeutic Significance

In humans, the gut microbiota (GM) are known to play a significant role in the metabolism of nutrients and drugs, immunomodulation, and pathogen defense by inhabiting the gastrointestinal tract (GIT). The role of the GM in the gut-brain axis (GBA) has been documented for different regulatory mechanisms and associated pathways and it shows different behaviors with individualized bacteria. In addition, the GM are known as susceptibility factor for neurological disorders in the central nervous system (CNS), regulating disease progression and being amenable to intervention. Bidirectional transmission between the brain and the GM occurs in the GBA, implying that it performs a significant role in neurocrine, endocrine, and immune-mediated signaling pathways. The GM regulates multiple neurological disorders by supplementing them with prebiotics, probiotics, postbiotics, synbiotics, fecal transplantations, and/or antibiotics. A well-balanced diet is critically important for establishing healthy GM, which can alter the enteric nervous system (ENS) and regulate multiple neurological disorders. Here, we have discussed the function of the GM in the GBA from the gut to the brain and the brain to the gut, the pathways associated with neurology that interacts with the GM, and the various neurological disorders associated with the GM. Furthermore, we have highlighted the recent advances and future prospects of the GBA, which may require addressing research concerns about GM and associated neurological disorders.

Safety, Efficacy, and Tolerability of Modified Atkins Diet in Persons With Drug-Resistant Epilepsy: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Modified Atkins Diet (MAD) has emerged as an adjuvant therapy in drug-resistant epilepsy (DRE). Most studies are in children, there is limited evidence for DRE in in adults. The present study aimed to investigate if MAD along with standard drug therapy (SDT) was indeed more effective than SDT alone in reducing seizure frequency and improving psychological outcomes at 6 months in Adolescents and adults with DRE (non-surgical).

METHODS

A prospective randomized controlled trial was conducted at tertiary care referral centre, in India. Persons with DRE aged 10-55 years attending outpatient epilepsy clinics between August 2015 and April 2019, who had more than two seizures/month despite using at least three appropriate anti-seizure medications (ASMs) at their maximum tolerated doses and had not been on any form of diet therapy for the past one year, were enrolled. Patients were assessed for the eligibility and randomly assigned to receive SDT plus MAD (intervention arm) or SDT alone (control arm).The primary outcome was>50% reduction in seizure- frequency, and the secondary outcomes were quality of life (QOL), behaviour, adverse events and rate of withdrawal at six months. Intention to treat analysis was performed.

RESULTS

243 patients were screened for eligibility; 160 patients (80 adults and 80 adolescents) were randomized to either intervention or Control arm. Demographic and clinical characteristics in both groups were comparable at baseline. At six months > 50% seizure reduction was seen in 26.2% in the intervention group versus 2.5 % in the control group (95% CI 13.5-33.9; p<0.001). Improvement in QOL was 52.1±17.6 in the intervention group versus 42.5±16.4 in the control group (mean difference, 9.6; 95%CI 4.3 to 14.9, p<0.001). However, behaviour scores could be performed in 49 patients and improvement was seen in intervention versus control group (65.6±7.9 versus 71.4±8.1, p=0.015) at the end of the study. One patient had weight loss; two patients had Diarrhoea.

DISCUSSION

MAD group demonstrated improvement in all aspects (reduction in seizure-frequency, and behavioural problems) compared to control group at the end of the study. MAD is an effective modality in controlling seizures, further research is required to assess its efficacy in terms of biomarkers along with descriptive metabolomics studies.

Anti-seizure medications and quality of life in person with epilepsy

Objective

The goal of this study was to determine the effects of mono-, bi-, and polytherapy anti-seizure medications (ASMs) in terms of seizure reduction and quality of life (QOL) in persons with epilepsy (PWE).

Methods

A cross-sectional observational study was conducted. All PWE with age <75 years were recruited and further classified into two groups: responders and non-responders, based on the response of the ASMs to the treatments for reduced seizure frequency since the last one year. Other demographic and clinical data such as seizure frequency, type of seizures, age at onset of seizures, and information about ASMs with their daily doses were assessed for the descriptive analysis. The quality of life was assessed in randomly selected PWE (n = 100) using the quality of life in epilepsy inventory-31 (QOLIE-31) in adults.

Results

With a total of 486 PWE, the median age (years) was comparable in both groups. Out of these the non-responders group was found to be significantly higher (77.8%) than the responders group (22.2%). In the responders group, the percentage of PWE who were on monotherapy was significantly higher (51.85 %) than those who were on polytherapy (17.59%), whereas in the non-responders group, 21.16% of PWE were on monotherapy and 44.86% were on polytherapy. The duration of epilepsy was similar in both groups, but the average seizure frequency was significantly higher in the non-responders. In QOL assessments, 43% of PWE were observed in the responders group, whereas 57% of PWE were found in the non-responders group. The overall comparative QOL scores were also significantly higher (p < 0.0001) in the responders group as compared to the non-responders group.

Conclusion

Our findings revealed that those PWE who were on monotherapy showed better reduction in seizure frequency and improved QOL in responder groups as compared to non-responder groups.

987 TACKLING OVERPRESCRIBING; WHAT ABOUT THE HABITUAL OFFENDER, PPI?

Introduction

Overprescribing is a serious problem in health systems internationally and can lead to preventable hospital assessments and admissions, even premature deaths1. Proton pump inhibitors (PPIs) are commonly prescribed in older people. They are associated with risk of C difficile infection, hypomagnesemia, osteoporosis, hypergastrinaemia, and are considered falls risk increasing drugs (FRID). Unfortunately, there isn’t a guideline which unifies the various indications of PPIs.

Method

303 discharges were screened from 2 acute geriatric wards between 01/10/2020 and 31/12/2020. After exclusions (34 deaths, 5 readmissions), 264 notes were reviewed. Those with a PPI mentioned on their discharge summaries were audited against both NICE dyspepsia guidelines and our hospital trust guidelines (PPI usage in those on co-medications), assessing whether long term use was advocated. Additional information was obtained from our hospital systems including digital health records.

Results

153/264(58%) patients had PPIs listed on their discharge summaries. Of those using PPIs, 146 (95%) had polypharmacy and 140(92%) had a CFS ≥5. More PPIs were commenced (18) than discontinued (16). Against NICE dyspepsia guidelines, 46/153(30%) patients did not require long term PPI treatment. 81/153 (53%) patients had a PPI prescribed due to anticoagulation, however, 37/81 (46%) did not fulfil our trust criteria for co-prescription.

Conclusion

PPI usage is prevalent in older people and often continued without a valid indication which could result in preventable harm in an already vulnerable cohort. There is a need to actively deprescribe PPIs within all healthcare settings. Our findings have been widely shared with our departmental colleagues and other relevant specialties and a guideline on long term use of PPIs in older people (&gt;65) has been developed. Going forward, we plan to re-audit against this new guideline in 6 months to assess improvement.

References 1. Good for you, good for us, good for everybody. Published 22/9/21.

1048 REDUCING RISK FROM WARFARIN- A COMPLETED AUDIT CYCLE ON NICE COMPLIANCE WITH WARFARIN FOR NVAF IN HOSPITALISED OLDER PEOPLE

Introduction

Traditionally Warfarin has been mainly used for stroke thromboprophylaxis in patients with atrial fibrillation but direct oral anticoagulant (DOAC) are increasingly being used as they have improved safety profiles with comparable efficacy. Recent data from National Reporting and Learning System (NRLS) have discovered safety incidents related to anticoagulation, predominantly Warfarin, contributing in excess of 10% of all medication errors. National institute for clinical excellence (NICE) recommends reassessing anticoagulation choice for patients on Warfarin with poor anticoagulation control, indicated by any of the following: 1 &gt; 2 INR values &lt;1.5 or &gt; 5 or 1 INR value &gt;8, within the past 6 months 2 &gt; Time in therapeutic range (TTR) &lt;65% Intervention An initial retrospective audit on 50 patients on Warfarin for NVAF performed between June—September 18 showed poor compliance with NICE. We reviewed the previous 6 months INR values and recorded any significant deviations outside of the therapeutic range as per NICE. TTR over the last 6 months was calculated using the Rosendaal method. Following departmental audit presentation, a reaudit was carried out between Jan-Aug 2019 to assess improvement.

Results

Median age was 87.5 compared to 83 in the first audit. Warfarin was correctly continued in 7/38(18%) in the 1st audit which improved to 9/28 (32%) in the second. Number of patients discharged on warfarin with unstable INRs decreased significantly from 26/32 (81%) patients in the 1st audit to 10/24 (42%) in the 2nd.

Discussion

Our reaudit shows significant reduction in continuation of warfarin on discharge in patients with unstable INRs (p = 0.0043 Fisher exact test). Although, there is a trend towards improvement with NICE compliance; in general, the compliance with NICE remains poor. We suggest geriatricians to proactively review the appropriateness of warfarin prescription and to consider a DOAC in preference to Warfarin in all elderly patients.

Endoscope-assisted (with robotic guidance and using a hybrid technique) interhemispheric transcallosal hemispherotomy: a comparative study with open hemispherotomy to evaluate efficacy, complications, and outcome

OBJECTIVEEndoscope-assisted hemispherotomy (EH) has emerged as a good alternative option for hemispheric pathologies with drug-resistant epilepsy.METHODSThis was a prospective observational study. Parameters measured included primary outcome measures (frequency, severity of seizures) and secondary outcomes (cognition, behavior, and quality of life). Blood loss, operating time, complications, and hospital stay were also taken into account. A comparison was made between the open hemispherotomy (OH) and endoscopic techniques performed by the senior author.RESULTSOf 59 cases (42 males), 27 underwent OH (8 periinsular, the rest vertical) and 32 received EH. The mean age was 8.65 ± 5.41 years (EH: 8.6 ± 5.3 years; OH: 8.6 ± 5.7 years). Seizure frequency per day was 7 ± 5.9 (EH: 7.3 ± 4.6; OH: 15.0 ± 6.2). Duration of disease (years since first episode) was 3.92 ± 1.24 years (EH: 5.2 ± 4.3; OH: 5.8 ± 4.5 years). Number of antiepileptic drugs per patient was 3.9 ± 1.2 (EH: 4.2 ± 1.2; OH: 3.8 ± 0.98). Values for the foregoing variables are expressed as the mean ± SD. Pathologies included the following: postinfarct encephalomalacia in 19 (EH: 11); Rasmussen's syndrome in 14 (EH: 7); hemimegalencephaly in 12 (EH: 7); hemispheric cortical dysplasia in 7 (EH: 4); postencephalitis sequelae in 6 (EH: 2); and Sturge-Weber syndrome in 1 (EH: 1). The mean follow-up was 40.16 ± 17.3 months. Thirty-nine of 49 (79.6%) had favorable outcomes (International League Against Epilepsy class I and II): in EH the total was 19/23 (82.6%) and in OH it was 20/26 (76.9%). There was no difference in the primary outcome between EH and OH (p = 0.15). Significant improvement was seen in the behavioral/quality of life performance, but not in IQ scores in both EH and OH (p < 0.01, no intergroup difference). Blood loss (p = 0.02) and hospital stay (p = 0.049) were less in EH.CONCLUSIONSEH was as effective as the open procedure in terms of primary and secondary outcomes. It also resulted in less blood loss and a shorter postoperative hospital stay.

Does surgery help in reducing stigma associated with drug refractory epilepsy in children?

INTRODUCTION

Epilepsy has several comorbidities and associated stigma. Stigma associated with epilepsy is well known and prevalent worldwide. Surgical treatment is an established treatment for drug refractory epilepsy. Following surgery in children, it is possible that the stigma may reduce, but such an effect has not been studied earlier.

MATERIALS AND METHODS

Analysis of prospectively collected data was performed for pediatric patients at a single tertiary center for treating epilepsy. Child stigma scale, as described by Austin et al., was used to evaluate stigma both pre- and postoperatively. Analysis was done using Paired t test.

RESULTS

In this study, following surgery, there was significant reduction of stigma (P<0.001). This was proportional to the reduction in seizures, though there were 9 (30%) patients, who due to persistent neurodisability did not have any reduction of stigma despite having good seizure outcome.

CONCLUSION

Surgery in drug-resistant epilepsy helps in reducing stigma. Seizure reduction is probably not the only factor responsible for a change in stigma outcome.

Surgery for Drug-Resistant Epilepsy in Children

BACKGROUND

Neurosurgical treatment may improve seizures in children and adolescents with drug-resistant epilepsy, but additional data are needed from randomized trials.

METHODS

In this single-center trial, we randomly assigned 116 patients who were 18 years of age or younger with drug-resistant epilepsy to undergo brain surgery appropriate to the underlying cause of epilepsy along with appropriate medical therapy (surgery group, 57 patients) or to receive medical therapy alone (medical-therapy group, 59 patients). The patients in the medical-therapy group were assigned to a waiting list for surgery. The primary outcome was freedom from seizures at 12 months. Secondary outcomes were the score on the Hague Seizure Severity scale, the Binet-Kamat intelligence quotient, the social quotient on the Vineland Social Maturity Scale, and scores on the Child Behavior Checklist and the Pediatric Quality of Life Inventory.

RESULTS

At 12 months, freedom from seizures occurred in 44 patients (77%) in the surgery group and in 4 (7%) in the medical-therapy group (P<0.001). Between-group differences in the change from baseline to 12 months significantly favored surgery with respect to the score on the Hague Seizure Severity scale (difference, 19.4; 95% confidence interval [CI], 15.8 to 23.1; P<0.001), on the Child Behavior Checklist (difference, 13.1; 95% CI, 10.7 to 15.6; P<0.001), on the Pediatric Quality of Life Inventory (difference, 21.9; 95% CI, 16.4 to 27.6; P<0.001), and on the Vineland Social Maturity Scale (difference, 4.7; 95% CI, 0.4 to 9.1; P=0.03), but not on the Binet-Kamat intelligence quotient (difference, 2.5; 95% CI, -0.1 to 5.1; P=0.06). Serious adverse events occurred in 19 patients (33%) in the surgery group, including hemiparesis in 15 (26%).

CONCLUSIONS

In this single-center trial, children and adolescents with drug-resistant epilepsy who had undergone epilepsy surgery had a significantly higher rate of freedom from seizures and better scores with respect to behavior and quality of life than did those who continued medical therapy alone at 12 months. Surgery resulted in anticipated neurologic deficits related to the region of brain resection. (Funded by the Indian Council of Medical Research and others; Clinical Trial Registry-India number, CTRI/2010/091/000525 .).

Purification, characterization and retting of Crotolaria juncea fibres by an alkaline pectin lyase from Fusarium oxysporum MTCC 1755

Using solid-state fermentation, production of an industrially important pectin lyase from a fungal strain Fusarium oxysporum MTCC 1755 was attempted, which was further subjected to purification and characterization. The enzyme was purified by three steps, namely ammonium sulfate fractionation, cation-exchange chromatography on CM cellulose followed by gel filtration chromatography using Sephadex G-100 column. A 16-fold purification with 31.2% yield and 3.2 U/mg specific activity was achieved. The optimum pH of the purified enzyme was 9.0 and stability ranged from pH 5.0-7.0 for 24 h. Optimum temperature of purified enzyme was found to be 40 °C while temperature stability ranged from 10 to 50 °C for 30 min. The K _m and k _cat of the enzyme was 1.75 mg/ml and 83.3 s^-1, respectively. The purified enzyme was found to be highly stimulated by Ca²⁺ ions while sugars like mannitol and sorbitol, and salts like NaCl and CaCl₂ enhanced the thermostability. The purified pectin lyase was found suitable for retting of Crotolaria juncea fiber.

Assessment of serum apolipoprotein B and apolipoprotein A-1 and their ratio in healthy full term small for gestational age newborns

BACKGROUND

Programmed changes in growth restricted fetuses can increase the risk of adulthood diseases due to elevated serum cholesterol and apolipoprotein-B (Apo-B) concentrations. Increasing evidence demonstrated the role of apoB/apoA-I ratio as a strong risk factor for cardiovascular diseases.

OBJECTIVE

To determine the concentration of cord blood lipoproteins and apolipoproteins as well as their correlation with birth weight.

METHODS

This cross-sectional study was conducted in a teaching institution in central India. Healthy full-term newborns, born out of normal vaginal deliveries, were recruited. Cases include term small for gestational age (SGA) babies while term appropriate for gestational age (AGA) babies were taken as controls. Their umbilical venous blood was collected and sent for biochemical analysis.

RESULTS

Out of 126 healthy newborns, 66 were cases and 60 were controls. Mean values of serum triglyceride (141.56±69.67 mg/dl vs. 113.67±33.38 mg/dl; p < 0.006; 95% CI = 8.31 to 47.46) and serum apo-B/apo-A-1 ratio (0.67±0.28 vs. 0.55±0.20; p < 0.007; 95% CI = 0.033 to 0.206) were significantly high and that of serum high density cholesterol (35.84±10.42 mg/dl vs. 40.73±11.70 mg/dl; p < 0.014; 95% CI = -8.79 to -0.98) and Apo-A1 [87.59±12.44 mg/dl vs. 101.87±35.07 mg/dl; p = 0.002; 95% CI = -23.39 to -5.16) were significantly low in SGA newborns. Serum cholesterol, very low-density cholesterol rlow-density cholesterol rand Apo-B did not show any significant difference. Among SGA newborns significant negative correlation was seen between birth weight and apo-B/apo-A1 and serum triglyceride, while birth weight and serum apo-A1 level showed significant positive correlation. There was no statistically significant correlation between birth weight and other parameters.

CONCLUSION

These findings further support the association of prenatal factors with lipid profile rand can serve as starting point for studying lipid transport system changes during early life in Indian population.

Remote sensing of bacterial response to degrading phytoplankton in the Arabian Sea

A remote sensing technique has been developed to detect physiological condition of phytoplankton using in situ and moderate imaging spectroradiometer (MODIS)-Aqua data. The recurring massive mixed algal bloom of diatom and Noctiluca scintillans in the Northern Arabian Sea during winter-spring was used as test bed to study formation, growth and degradation of phytoplankton. The ratio of chlorophyll (chl) to particulate organic carbon (POC) was considered as an indicator of phytoplankton physiological condition and used for the approach development. Algal blooms represent the areas of new production, and therefore, knowledge of their degradation is important to the study microbial loop and export carbon flux. Relation of chl/POC ratio with bacterial abundance revealed Gaussian distribution. Bacteria were strongly correlated with POC, and hence, the latter which is available from satellite data could be used as a proxy for remote assessment of bacteria. Thresholds for active and degrading phytoplankton were determined using the ratio computed from the satellite data. The criteria were implemented on MODIS data to generate an image representing distribution of degrading algal bloom. Bacteria abundance data from two validation cruises during dinoflagellate and cyanobacteria bloom confirmed well match up of phytoplankton degradation information from the satellite. Comparison of environmental parameters during decay phase of dinoflagellate (N. scintillans bloom (winter) and Trichodesmium bloom (summer) revealed that degradation after active Trichodesmium bloom was more severe as compared to the N. scintillans. The present study also highlights the prediction capability of phytoplankton degradation using a time series of satellite retrieved chlorophyll/POC images.

MODIS-Aqua detects Noctiluca scintillans and hotspots in the central Arabian Sea

Northern Arabian Sea is considered as an ecologically sensitive area as it experiences a massive upwelling and long-lasting algal bloom, Noctiluca scintillans (green tide) during summer and spring-winter, respectively. Diatom bloom is also found to be co-located with N. scintillans and both have an impact on ecology of the basin. In-house technique of detecting species of these blooms from Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data was used to generate a time-series of images revealing their spatial distribution. A study of spatial-temporal variability of these blooms using satellite data expressed a cyclic pattern of their spread over a period of 13 years. An average distribution of the blooms for January-March period revealed a peak in 2015 and minimum in 2013. Subsequently, a time-series of phytoplankton species images were generated for these 2 years to study their inter-annual variability and the associated factors. Species images during active phase of the bloom (February) in 2015 indicated development of N. scintillans and diatom in the central Arabian Sea also, up to 12° N. This observation was substantiated with relevant oceanic parameters measured from the ship as well as satellite data and the same is highlight of the paper. While oxygen depletion and release of ammonia associated with N. scintillans are detrimental for waters on the western side; it is relatively less extreme and supports the entire food chain on the eastern side. In view of these contrasting eco-sensitive events, it is a matter of concern to identify biologically active persistent areas, hot spots, in order to study their ecology in detail. An ecological index, persistence of the bloom, was derived from the time-series of species images and it is another highlight of our study.

Endoscopic-Assisted (Through a Mini Craniotomy) Corpus Callosotomy Combined With Anterior, Hippocampal, and Posterior Commissurotomy in Lennox-Gastaut Syndrome

BACKGROUND:

Corpus callosotomy is a palliative procedure especially for Lennox-Gastaut semiology without localization with drop attacks.

OBJECTIVE:

To describe endoscopic-assisted complete corpus callosotomy combined with anterior, hippocampal, and posterior commissurotomy.

METHODS:

Patients with drug refractory epilepsy having drop attacks as the predominant seizure type, bilateral abnormalities on imaging, and moderate to severe mental retardation were included. All underwent a complete workup (including magnetic resonance imaging).

RESULTS:

Patients (n = 16, mean age 11.4 ± 6.4 years, range 6-19 years) had a mean seizure frequency of 24.5 ± 19.8/days (range 1-60) and a mean intelligence quotient of 25.23 ± 10.71. All had syndromic diagnosis of Lennox-Gastaut syndrome, with the following etiologies: hypoxic insult (10), lissencephaly (2), bilateral band heterotropia (2), and microgyria and pachygyria (2). Surgery included complete callosotomy and the section of anterior and posterior commissure by microscopic approach through a mini craniotomy (11) and endoscopic-assisted approach (5). Complications included meningitis (1), hyperammonemic encephalopathy (2), and acute transient disconnection (5). There was no mortality or long-term morbidity. Mean follow-up was 18 ± 4.7 months (range 16-27 months). Drop attacks stopped in all. Seizure frequency/duration decreased &gt;90% in 10 patients and &gt;50% in 5 patients, and increased in 1 patient. All patients attained presurgical functional levels in 3 to 6 months. Child behavior checklist scores showed no deterioration. Parental questionnaires reported 90% satisfaction attributed to the control of drop attacks. The series was compared retrospectively with an age/sex-matched cohort (where a callosotomy only was performed), and showed better outcome for drop attacks (P &lt; .003).

CONCLUSION:

This preliminary study demonstrated the efficacy and safety of complete callosotomy with anterior, hippocampal, and posterior commissurotomy in Lennox-Gastaut syndrome (drop attacks) with moderate to severe mental retardation.

Outcome of Both Bone Forearm Fracture Fixation in Children by Rush Nails

INTRODUCTION

Forearm fractures are common upper limb injuries among children and usually treated non-operatively. Failure of non-operative treatment, open injuries and multiple fractures are the indications for surgery in paediatric both bone forearm fractures. Intramedullary nailing is considered as minimally invasive procedure with excellent to fair outcomes but it is not free of complications. We reviewed the results and evaluated the outcomes of IM fixation of forearm fractures in children by Rush nails to understand the risks and complications associated with these procedures.

METHODS

A retrospective crossectional study of all paediatric patients treated for diaphyseal forearm fractures for period of five years in a tertiary care setup. Complications were classified according to modified Clavien-Dindo complication classification system. Outcomes were graded depending upon complication grade along with range of motion of forearm.

RESULTS

A total of 25 patients were included in the study. Mean time for fracture union was 10.56 weeks. Outcomes were excellent in 16 (64%), good in 7 (28%), fair in 2 (8%) patients and no poor outcome was noted. Ten minor complications were seen.

CONCLUSION

Fixation of paediatric forearm fractures by intramedullary Rush nail is minimally invasive procedure and outcomes are excellent to fair with acceptable complication rates.

Endoscopy-Assisted Interhemispheric Transcallosal Hemispherotomy

BACKGROUND:

Various hemispherotomy techniques have been developed to reduce complication rates and achieve the best possible seizure control.

OBJECTIVE:

To present a novel and minimally invasive endoscopy-assisted approach to perform this procedure.

METHODS:

Endoscopy-assisted interhemispheric transcallosal hemispherotomy was performed in 5 children (April 2013-June 2014). The procedure consisted of performing a small craniotomy (4 × 3 cm) just lateral to midline using a transverse skin incision. After dural opening, the surgery was performed with the assistance of a rigid high-definition endoscope, and bayoneted self-irrigating bipolar forceps and other standard endoscopic instruments. Steps included a complete corpus callosotomy followed by the disconnection of the hemisphere at the level of the basal nuclei and thalamus. The surgeries were performed in a dedicated operating room with intraoperative magnetic resonance imaging and neuronavigation. Intraoperative magnetic resonance imaging confirmed a total disconnection.

RESULTS:

The pathologies for which surgeries were performed included sequelae of middle a cerebral artery infarct (n = 2), Rasmussen syndrome (n = 1), and hemimegalencephaly (2). Four patients had an Engel class I and 1 patient had a class II outcome at a mean follow-up of 10.2 months (range, 3-14 months). The mean blood loss was 80 mL, and mean operating time was 220 minutes. There were no complications in this study.

CONCLUSION:

This study describes a pilot novel technique and the feasibility of performing a minimally invasive, endoscopy-assisted hemispherotomy.

Species identification of mixed algal bloom in the Northern Arabian Sea using remote sensing techniques

Oceanic waters of the Northern Arabian Sea experience massive algal blooms during winter-spring (mid Feb-end Mar), which prevail for at least for 3 months covering the entire northern half of the basin from east to west. Ship cruises were conducted during winter-spring of 2001-2012 covering different stages of the bloom to study the biogeochemistry of the region. Phytoplankton analysis indicated the presence of green tides of dinoflagellate, Noctiluca scintillans (=N. miliaris), in the oceanic waters. Our observations indicated that diatoms are coupled and often co-exist with N. scintillans, making it a mixed-species ecosystem. In this paper, we describe an approach for detection of bloom-forming algae N. scintillans and its discrimination from diatoms using Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data in a mixed-species environment. In situ remote sensing reflectance spectra were generated using Satlantic™ hyperspectral radiometer for the bloom and non-bloom waters. Spectral shapes of the reflectance spectra for different water types were distinct, and the same were used for species identification. Scatter of points representing different phytoplankton classes on a derivative plot revealed four diverse clusters, viz. N. scintillans, diatoms, non-bloom oceanic, and non-bloom coastal waters. The criteria developed for species discrimination were implemented on MODIS data and validated using inputs from a recent ship cruise conducted in March 2013.

Correlation of saliva and serum free valproic acid concentrations in persons with epilepsy

PURPOSE

Therapeutic drug monitoring (TDM) of antiepileptic drugs (AEDs) in serum is frequently used in clinical settings however saliva could be an alternative to measure free concentration of drugs. In the present study, we observed the possible correlation of VPA concentration between serum and saliva in persons with epilepsy (PWE).

METHODS

A total of 59 paired serum and saliva samples were assayed from 65 consecutive PWE (51 males and 14 females; age range 9-65 years). Patients were subjected to either VPA monotherapy or its combination with other AEDs for at least three months. Steady state trough concentration of unbound VPA drug was quantified using HPLC. The correlation between serum and saliva free VPA concentration was evaluated.

RESULTS

Out of 65 patients, 27 were on monotherapy of VPA and 38 were on VPA with other antiepileptic drugs. Saliva VPA concentration significantly correlated with serum free VPA concentration (p<0.05). Poor correlation was observed between serum and saliva VPA concentration with the daily dose (p>0.05) respectively.

CONCLUSIONS

Our study reveals that serum and saliva VPA concentrations are significantly associated in PWE. These associations may facilitate monitoring and evaluation of VPA levels non-invasively for PWE.

Close Versus Limited Open Method of Ender's Nail Fixation in Paediatric Femoral Shaft Fractures

INTRODUCTION

There are various surgical options for treating fracture of femoral shaft in children. Here we compare the results of close with limited open method of Ender's nails fixation of femoral shaft fractures in children.

METHODS

We studied 60 children with femoral shaft fractures in age group 5-15 years. Ender's nail fixation was done by close technique in 40 cases and in 20 cases by limited open technique.

RESULTS

The mean operative time was significantly high in limited open group being 64 minutes in comparison to 50 minutes in close group. There was no significant difference between close and limited open groups with respect to time for partial weight bearing and time for full weight bearing. Fracture united sooner in close group as compared to open group. Union was achieved in all patients within a mean of 11 weeks in close group in comparison to 12.4 weeks in open group. According to the Flynn criteria in close group 34 patients had excellent results, 6 had satisfactory and none poor. In limited open group outcome was excellent in 14 patients, satisfactory in 4 patients and 2 had poor result. There was no significant difference in outcome based on Flynn criteria between two groups.

CONCLUSIONS

Though operative time is more and healing is delayed in Ender's nail fixation by limited open technique, there is no statistical difference in final outcome as per Flynn criteria between close and limited open technique of Ender's nail fixation of femoral shaft fractures in children.

Can community-based, low-cost antenatal care in the third trimester of pregnancy reduce the incidence of low birth weight newborns?

OBJECTIVE

To determine if community-based, low-cost interventions during third trimester of pregnancy can reduce the incidence of low birth weight babies.

METHODS

In a case control study, 290 pregnant women from a slum area were registered in the beginning of third trimester of pregnancy and provided full antenatal care comprising fortnightly check up, one IFA tablet daily, counseling for minimum one-and-a-half hour post-lunch rest in left lateral position, additional diet to ensure minimum 2,200 kcal per day, and management of clinical conditions, if any. An equal number of pregnant women belonging to the same slum area were registered as control who received routine antenatal services from the existing health care facilities. The birth weight of the babies in the two groups were recorded and compared. Test of significance and correlation coefficient were applied to the data.

RESULTS

Mean birth weight of the babies of the Subjects was 2.76 kg (SD 0.39) compared to mean birth weight of 2.57 kg (SD 0.36) of the babies in the Control group. Incidence of low birth weight babies among subjects who consumed minimum 2,400 kcal per day, had one-and-a-half hour post-lunch rest in left lateral position and who consumed one tablet of IFA (100 mg iron and 5 mg folic acid) per day during the last trimester of pregnancy was lower (17.6 %) as compared with women in the Control group (36.2 %). The difference in the mean birth weight of newborns of the two groups was statistically significant (t = 2.52, p < 0.01).

CONCLUSIONS

Incidence of low birth weight babies can be significantly reduced by providing simple, low-cost care to pregnant women during the last trimester of pregnancy in the community setting.

Applicability of the new ILAE classification for epilepsies (2010) in persons with epilepsy at a tertiary care center in India

PURPOSE

To test the applicability of the new International League Against Epilepsy (ILAE) 2010 classification for epilepsies and to compare it with the ILAE 1989 classification and the ILAE 2001 diagnostic scheme in developing countries with limited resources such as India.

METHODS

Prospective data of 500 consecutive patients with epilepsy, presenting in neurology department of All India Institute of Medical Sciences, was collected from January 2011 to June 2012 and analyzed according to the three systems proposed by ILAE in 1989, 2001, and 2010.

KEY FINDINGS

All 500 patients could be classified in the ILAE 1989 classification system, but only 413 in the ILAE 2001 diagnostic scheme (in axes 3 and 4) and 420 in the ILAE 2010 classification system. Leading categories were localization-related epilepsies, symptomatic focal epilepsies, perinatal insult, and epilepsies attributed to structural and metabolic cause in ILAE 1989, 2001 axis 3, 2001 axis 4, and 2010 systems, respectively. The ILAE 1989 classification system could categorize significantly greater numbers of patients compared to the 2001 and 2010 systems, whereas the latter two remained similar.

SIGNIFICANCE

A large group of patients remained unclassified in the new classification system despite our tremendous gain in knowledge through improved imaging, genomics, and molecular biology, and so on, which could be attributed to lack of availability of facilities in developing countries. Dichotomy of localization-related and generalized epilepsy still makes for a fundamental and pragmatic working diagnosis and guides the physician about the extent of investigations and treatment especially in "epilepsies of unknown cause."

Surgical Management of Cervical Spondylotic Myelopathy

Introduction: The surgical procedure by the anterior, posterior and combined antero-posterior approaches had applied for the treatment of cervical spondylotic myelopathy.  Methods: During the treatment process, all patients were pre-operatively as well post-operatively graded according to Japanese Orthopaedics Association. Several surgical methods such as anterior approach, posterior approach, and combined antero-posterior approach have been addressed for CSM patients, with the choice based on the pathogenesis of the myelopathy. The main indications for surgery were evidence of myelopathy on physical examinations, a JOA score below 13 points help with spinal cord compression observed on plain X-ray, CT scan, MRI studies.  Results: The pre-operative JOA scores were 7.60±1.23 in laminoplasty, 8.30±1.03 in diskectomy and corpectomy and 7.10±1.20 in combined antero-posterior approach patients. At the follow-up after three months the JOA scores were laminoplasty 13.30±1.30, diskectomy and corpectomy 13.55±1.15 and combined antero-posterior 13.50±1.08. The JOA recovery rate averaged, 61.08±11.25% in laminoplasty, 60.67±10.60% in diskectomy and corpectomy and 64.67±10.72% in combined anteroposterior approach. The high- signal intensity changed to normal in 18 out of 28 and no any kyphotic change and instability were found in cervical spine at the follow up.  Conclusions: Patients with OPLL (continuous, segmental and mixed type), stenosis of cervical spinal canal, multilevel cervical spondylosis, large and high ossification of IVDP with stenosis were improved with laminoplasty. Patients with PIVD, CSM with kyphosis, post laminectomy , OPLL herniated type, unstable vertebral alignment, stenosis by osteophytes, were improved with anterior approach . Ossified or deformed OPLL, unstable vertebral with stenosis ,OPLL or OYL with cervical meandearing (swan-neck) were improved with Combined anterior and posterior approach. Keywords: cervical spondylotic mylopathy, anterior cervical diskectomy and fusion, corpectomy.

Surgical management of cervical spondylotic myelopathy

INTRODUCTION

The surgical procedure by the anterior, posterior and combined antero-posterior approaches had applied for the treatment of cervical spondylotic myelopathy.

METHODS

During the treatment process, all patients were pre-operatively as well post-operatively graded according to Japanese Orthopaedics Association. Several surgical methods such as anterior approach, posterior approach, and combined antero-posterior approach have been addressed for CSM patients, with the choice based on the pathogenesis of the myelopathy. The main indications for surgery were evidence of myelopathy on physical examinations, a JOA score below 13 points help with spinal cord compression observed on plain X-ray, CT scan, MRI studies.

RESULTS

The pre-operative JOA scores were 7.60±1.23 in laminoplasty, 8.30±1.03 in diskectomy and corpectomy and 7.10±1.20 in combined antero-posterior approach patients. At the follow-up after three months the JOA scores were laminoplasty 13.30±1.30, diskectomy and corpectomy 13.55±1.15 and combined antero-posterior 13.50±1.08. The JOA recovery rate averaged, 61.08±11.25% in laminoplasty, 60.67±10.60% in diskectomy and corpectomy and 64.67±10.72% in combined antero-posterior approach. The high-signal intensity changed to normal in 18 out of 28 and no any kyphotic change and instability were found in cervical spine at the follow up.

CONCLUSIONS

Patients with OPLL (continuous, segmental and mixed type), stenosis of cervical spinal canal, multilevel cervical spondylosis, large and high ossification of IVDP with stenosis were improved with laminoplasty. Patients with PIVD, CSM with kyphosis, post laminectomy, OPLL herniated type, unstable vertebral alignment, stenosis by osteophytes, were improved with anterior approach. Ossified or deformed OPLL, unstable vertebral with stenosis, OPLL or OYL with cervical meandearing (swan-neck) were improved with Combined anterior and posterior approach.

Do gene polymorphism in IL-1β, TNF-α and IL-6 influence therapeutic response in patients with drug refractory epilepsy?

PURPOSE

Pro-inflammatory cytokines may play an important pathophysiological role in patients with epilepsy. To understand the role of genes encoding pro-inflammatory cytokines in epilepsy, this study aimed to evaluate the polymorphisms of the promoter regions of IL-1β-511C>T (rs16944), TNF-α-308G>A (rs1800629) and IL-6-174G>C (rs1800795) genes and to look into the interaction between these genes in influencing seizure susceptibility, seizure frequency and response to therapy.

METHODS

The comparative frequency of polymorphism was determined in rs16944, rs1800629 and rs1800795 using PCR-RFLP in a group of 120 persons with epilepsy (PWE) and 110 ethnically matched healthy subjects of comparable age and sex in the North Indian population.

RESULTS

Alleles and genotypes of rs16944, rs1800629 and rs1800795 were not found to influence the odds ratio of having susceptibility to epilepsy. Also gene-gene interaction of possible nine combinations of these genes did not show any positive association with epilepsy. The genotype and allelic frequency of rs1800795 showed a significant association (p<0.05) in seizure frequency (number of seizures/6-months) and drug refractory epilepsy. However, the genotype and allelic frequency of rs16944 and rs1800629 were not found to have such effect.

CONCLUSION

This study demonstrates that the rs16944, rs1800629 and rs1800795 polymorphism does not act as a strong susceptibility factor for epilepsy in North Indian population. The genotypic association of rs1800795 with seizure frequency and drug-refractory epilepsy raises the issue that a specific set of polymorphic genes can influence seizures and therapeutic response in epilepsy.

Problem based review: the patient presenting with an acutely swollen arm

A 69 year old female presented to the Emergency Department with swelling of her right arm and elbow, one week following a fall which resulted in a fracture of the middle third of her right clavicle (Figure 1). The forearm was hot and tender and the arm and hand function were somewhat impaired by swelling, but sensation was intact. Initial bloods were unremarkable, apart from a mild neutrophilia.

An ultrasonographic evaluation of solitary muscular and soft tissue cysticercosis

BACKGROUND

Cysticercosis in humans is infection with the larval form (cysticercus cellulosae) of the pork tapeworm T. solium. Encystment of larvae can occur in almost any tissue. The location of cysts in order of frequency is the central nervous system, subcutaneous tissue and striated muscle, vitreous humour of the eye and, rarely, other tissues. High resolution ultrasound can be used in the diagnosis of muscular and soft tissue cysticercosis.

OBJECTIVE

The aim of this study is to evaluate the ultrasonographic findings in cases of muscular and soft tissue cysticercosis.

MATERIALS AND METHODS

It was a retrospective review of the cases of muscular and soft tissue cysticercosis which were diagnosed by ultrasound during June 2007 to May 2009 in the department of Radiology and Imaging, Nepalgunj Medical College Teaching Hospital. A total of six patients were evaluated.

RESULT

There were four males and two females. Age of the patient ranged from 18 to 50 years. All of the patients presented with a swelling with pain in fi ve of them. There was a wide variation in the location of the cysts. In all cases ultrasound revealed a cystic lesion with an echogenic eccentric pedunculated nodule attached to the wall. The mean diameter of the cyst was 6mm. Smooth wall was present in fi ve cases whereas one of the cysts revealed irregular wall. Pericystic inflammatory changes were seen in the adjacent muscles.

CONCLUSION

Ultrasound is a safe and non-invasive method that can be used in the diagnosis of muscular and soft tissue cysticercosis.

Block of Inward Rectifying K + Channels (K IR ) Inhibits Bradykinin-Induced Vasodilatation in Human Forearm Resistance Vasculature

Objective— To investigate the possible involvement of inward rectifying K + channels (K IR ) in the response of human resistance vessels to bradykinin in vivo.

Methods and Results— Drugs were administered via the brachial artery in healthy male volunteers and forearm blood flow was measured by venous occlusion plethysmography. Inhibition of K IR by barium chloride (4 μmol min −1 ) alone or with additional inhibition of Na + /K + ATPase (ouabain 2.7 μmol min −1 ) reduced responses to bradykinin (30 pmol min −1 ), by 26±8.3% and 36±7.2%, respectively (each P <0 0.05). Barium with ouabain plus inhibitors of prostaglandin (PG) and nitric oxide synthesis inhibited but did not abolish responses to bradykinin (51±2.8% inhibition; P <0.01); norepinephrine (240 pmol min −1 ) caused similar reduction of baseline blood flow, as did this combination of inhibitors, but did not significantly inhibit the response to bradykinin. Barium plus ouabain did not significantly reduce responses to acetylcholine or albuterol.

Conclusion— A component of the vasodilator response to bradykinin in human forearm vasculature is mediated by K IR .

Constitutive expression of prostaglandin endoperoxide G/H synthetase (PGHS)-2 but not PGHS-1 in hum an tracheal epithelial cells in vitro

Primary cultures of human tracheal epithelial (HTE) cells cultured in vitro, in defined serum-free media, express prostaglandin endoperoxide G/H synthase (PGHS) activity and produce prostaglandin E2 (PGE2). In contrast to every other cell type studied to date, HTE cells appear to constitutively express PGHS-2, the 'inducible' form of the enzyme, while expressing little or no PGHS-1, the 'housekeeping' isoenzyme in vitro. Prostaglandin synthesis in HTE cells was reduced by a selective PGHS-2 inhibitor, N-[2-cyclohexyloyl-4-nitrophenyl] methane-sulfonamide (NS398), with an IC50 of approximately 1 microM. Immunoblotting and immunoprecipitation of enzymatic activity with isozyme-specific antisera revealed only the PGHS-2 isoform. Full length human cDNA probes detected only PGHS-2 message in Northern blots. Neither PGHS-2 activity nor mRNA levels were dependent on, nor stimulated by peptide growth factors present in the defined serum-free growth medium, or by serum. Prolonged maintenance in the absence of retinoic acid, however, lead to a decline in PGHS activity. Phorbol-myristate acetate (PMA) induced PGHS-2 activity and mRNA and neither PMA-induced, nor constitutive PGHS-2 expression was suppressed by corticosteroids. Actinomycin D-treatment for six hours reduced the PGHS-2 activity and mRNA to only 50% that of untreated cells, suggesting that PGHS-2 mRNA is extremely stable in these cells. HTE cells, at least in vitro, appear unique among prostaglandin-producing cells in that they express PGHS-2, constitutively, independent of regulation by growth factors, serum, or corticosteroids and fail to express PGHS-1 under any culture condition studied.