Regulation of the Ca2+ Channel CaV1.2 Supports Spatial Memory and Its Flexibility and LTD

Widespread release of norepinephrine (NE) throughout the forebrain fosters learning and memory via adrenergic receptor (AR) signaling, but the molecular mechanisms are largely unknown. The β2 AR and its downstream effectors, the trimeric stimulatory Gs-protein, adenylyl cyclase (AC), and the cAMP-dependent protein kinase A (PKA), form a unique signaling complex with the L-type Ca2+ channel (LTCC) CaV1.2. Phosphorylation of CaV1.2 by PKA on Ser1928 is required for the upregulation of Ca2+ influx on β2 AR stimulation and long-term potentiation induced by prolonged theta-tetanus (PTT-LTP) but not LTP induced by two 1-s-long 100-Hz tetani. However, the function of Ser1928 phosphorylation in vivo is unknown. Here, we show that S1928A knock-in (KI) mice of both sexes, which lack PTT-LTP, express deficiencies during initial consolidation of spatial memory. Especially striking is the effect of this mutation on cognitive flexibility as tested by reversal learning. Mechanistically, long-term depression (LTD) has been implicated in reversal learning. It is abrogated in male and female S1928A knock-in mice and by β2 AR antagonists and peptides that displace β2 AR from CaV1.2. This work identifies CaV1.2 as a critical molecular locus that regulates synaptic plasticity, spatial memory and its reversal, and LTD.SIGNIFICANCE STATEMENT We show that phosphorylation of the Ca2+ channel CaV1.2 on Ser1928 is important for consolidation of spatial memory and especially its reversal, and long-term depression (LTD). Identification of Ser1928 as critical for LTD and reversal learning supports the model that LTD underlies flexibility of reference memory.

ARMC5-associated Bilateral Macronodular Adrenocortical Hyperplasia: A Novel Germline Variant Associated with Concomitant Papillary Thyroid Carcinoma and Meningioma

Introduction/Objective

Germline mutations in the tumor suppressor gene Armadillo-containing repeat protein 5 gene (ARMC5) have been very recently recognized as a cause for a familial form of bilateral macronodular adrenocortical hyperplasia (BMAH), itself a rare cause of Cushing syndrome. In patients with ARMC5 mutations, scattered case reports have also shown an association with meningiomas and cancers of the pancreas, breast, colon, and thyroid.

Methods/Case Report

We present the case of BMAH, arising in a 61-year-old female with a history of metastatic papillary thyroid carcinoma and meningioma. The patient presented with bilateral but asymmetric adrenal enlargement (right greater than left) and Cushing syndrome. Given history of thyroid cancer and meningioma, genetics referral was ordered. Counseling revealed a pedigree without a strongly evident familial pattern of hereditary endocrine neoplasia characteristic of any of the more common inherited dispositions to endocrine neoplasia. Additionally, a targeted capture-based NGS germline genetic sequencing study for variants in 12 genes associated with associated with hereditary thyroid cancer was performed and negative. However, based on recent scholarship regarding ARMC5, follow-up germline NGS and Sanger sequencing studies encompassing the entire coding sequences of ARMC5 were ordered. These identified a germline, heterozygous, novel (not in ClinVar) but likely pathogenic variant in (c.802C>T, p.Arg268*), providing a likely explanation for the patient’s BMAH. In attempt to control the patient’s Cushing symptoms, right-sided adrenalectomy was performed, revealing a 220g adrenal gland with marked multinodular hyperplasia with solid, nested, and tubular architecture.

Results (if a Case Study enter NA)

NA

Conclusion

While case reports exist describing an association between other ARMC5 mutations and BMAH with concomitant meningiomas and/or malignancies, greater study is needed in order to better characterize the phenotypic spectrum of this disease. Our experience with this case not only reports a novel, apparently pathogenic mutation, but it documents its association with BMAH and, additionally, papillary thyroid carcinoma and meningioma.

Maslinic acid differentially exploits the MAPK pathway in estrogen-positive and triple-negative breast cancer to induce mitochondrion-mediated, caspase-independent apoptosis

Breast cancer accounts for 1.4 million new cases every year. Triple-negative breast cancer (TNBC) is one the leading cause of mortality in developing countries and is associated with early age onset (under 40 years old). Chemotherapy has a poor success rate in patients with TNBC as compared to other types of breast cancers. It is due to the lack of expression of three validated molecular markers for breast cancer, the estrogen and progesterone receptors, and the amplification of HER-2/Neu. Therefore, a clear need exists for a greater understanding of TNBC at all levels and for the development of better therapies. We have studied the anti-tumor effects of a potential drug, maslinic acid, which can be extracted from olive oil industry waste. This natural product showed inhibitory effect at concentrations ranging from 30 to 50 µM within 24 h. It exhibited divergent effects in cell cycle progression for the MCF7 (estrogen positive) cell line when compared with TNBCs like MDA-MB-231 and MDA-MB-468. Also, maslinic acid treatment altered the mitochondrial membrane electrochemical potential and the reactive oxygen species (ROS) levels to cause a caspase-independent programmed cell death. In silico approaches and immunoblotting suggested the involvement of the MAPK pathway explaining the variability in cell cycle progression along with the apoptotic cell death caused by maslinic acid.

Perioperative Management of Patients Treated with Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers: A Quality Improvement Audit

Previous studies have shown that patients continuing angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers on the day of surgery are more likely to have significant intraoperative hypotension, higher rates of postoperative acute kidney injury and lower incidences of postoperative atrial fibrillation. However, many of these studies were prone to bias and confounding, and questions remain over the validity of these outcomes. This observational, before-and-after quality mprovement audit aimed to assess the effect of withholding these medications on the morning of surgery. We recruited 323 participants, with 83 (26%) having their preoperative angiotensin-converting enzyme inhibitor (ACEi) or angiotensin II receptor blocker (ARB) withheld on the day of surgery. There were only very small Spearman rank-order correlations between time since last dose of these medications (rho −0.12, P=0.057) and intraoperative and recovery room intravenous fluid administration (rho −0.11, P=0.042). There was no statistically significant difference between the continued or withheld groups in vasopressor (metaraminol use 3.5 [1.5–8.3] mg versus 3.5 [1.5–8.5] mg, P=0.67) or intravenous fluid administration (1000 ml [800–1500] ml versus 1000 [800–1500] ml, P=0.096), nor rates of postoperative acute kidney injury (13% vs 18%, P=0.25) or atrial fibrillation (15% versus 18%, P=0.71). This audit found no significant differences in measured outcomes between the continued or withheld ACEi/ARB groups. This finding should be interpreted with caution due to the possibility of confounding and an insufficient sample size. However, as the finding is in contrast to many previous studies, future prospective randomised clinical trials are required to answer this important question.

Chinese whispers in the post anaesthesia care unit (PACU)

We audited verbal handover of information by anaesthetists to recovery room nurses based on Situation, Background, Assessment and Recommendation. In Audit A, 100 handovers for elective procedures were included. For audit B, a second cohort of 100 patients was examined post educational session. There was an improvement in handover of medical background (46.15% Audit A, 77% Audit B, p < 0.001) and allergy status (42% Audit A, 56% Audit B, p = 0.048). Handing over immediate postoperative instructions remained unchanged (58% Audit A, 59% Audit B) and there was a 4% decline in verbal handover of instructions for ward care. Nurse satisfaction with handovers improved by 12%. We conclude that a structured process of information transfer, led to improved handover of immediate care. Further education focussed on the importance of instructions for the ward to maintain continuity of care is recommended.

Aneurysmal bone cyst of maxilla existing concurrently with a giant cell granuloma of mandible: a case report of an unusual presentation

Aneurysmal bone cysts (ABCs) are relatively rare but well-described expansile, osteolytic psuedocysts are most commonly seen in the long bones, pelvis, and vertebra. Although a well-described lesion, much confusion exists in its pathogenesis especially of the associations of this lesion with other lesions. Approximately, one-third of patients with ABC present simultaneously with another bone pathology. The aim of this paper is to describe a rare case of simultaneously occurring ABC of the maxilla and mandible with the mandibular lesion occurring predominantly as a giant cell granuloma. The paper discusses the various histopathological variations of ABC as well as different lesions associated with ABC and tries to provide a review of different pathogenesis theories of this interesting lesion.

Multiple displacement amplification as a pre-polymerase chain reaction (pre-PCR) to detect ultra low population of Ralstonia solanacearum (Smith 1896) Yabuchi et al. (1996)

AIMS

To develop a reliable and sensitive protocol for detection of Ralstonia solanacearum using MDA-PCR (Multiple displacement amplification-PCR amplification).

METHODS AND RESULTS

MDA-PCR technique was performed on pure cell lysates as well as soil samples. Pure cell lysate as well as that of soil DNA was used as template in MDA reaction. MDA of template DNA was carried out in the presence of sample buffer, reaction buffer and enzyme mix (Phi 29 DNA polymerase and random hexamers). The MDA amplified DNA was used for PCR amplification using R. solanacearum -specific PCR primers. MDA-PCR could detect as low as 1 colony forming unit (CFU ml(-1)) of bacteria within 8 h including DNA isolation.

CONCLUSION

MDA followed by standard PCR facilitated the detection of pathogen from very low count samples. The method is of great importance in managing the brown rot disease of potato.

SIGNIFICANCE AND IMPACT OF STUDY

The ultrasensitive detection technique developed in the present study is sensitive and speedy enough to be included into integrated wilt disease control programmes.

A meta-analysis of trials comparing Cypher and Taxus stents in patients with obstructive coronary artery disease

AIMS

Drug-eluting stents have been shown to be superior to bare metal stents in reducing restenosis rates. Recently head-to-head trials comparing sirolimus-eluting stents and paclitaxel-eluting stents have been reported. An early combined analysis of these comparative trials is needed. The present meta-analysis was carried out to compare the effects of sirolimus-eluting stents with paclitaxel-eluting stents on the restenosis rate, major adverse cardiac events and late loss of arterial lumen diameter in patients with obstructive coronary artery disease.

METHODS

Electronic (Medline, Cochrane and Embase) and manual search (Index Medicus and cross references of retrieved articles) were carried out for all the relevant articles up till March 2005. Only randomized trials with adequate data for calculation of odds ratio for restenosis rates and major adverse cardiac events using the method of DerSimonian & Laird and standardized mean difference for late loss of arterial lumen diameter were included.

RESULTS

Four studies were found to be eligible for inclusion in the meta-analysis. Restenosis rate and late loss of arterial lumen diameter were significantly reduced by sirolimus-eluting stents as compared with paclitaxel-eluting stents (OR 0.598, 95% CI 0.400, 0.893, pooled mean difference -0.414, 95% CI -0.492, 0.336, respectively). The incidence of major adverse cardiac events was less with sirolimus-eluting stents as compared with paclitaxel-eluting stents (OR 0.727, 95% CI 0.518-1.018) but the results were not statistically significant.

CONCLUSIONS

Sirolimus-eluting stents are superior to paclitaxel-eluting stents in decreasing restenosis rate and late loss of arterial lumen diameter. However, no statistically significant difference in major adverse cardiac events was noted between the two stents.

A randomized controlled clinical trial to evaluate the efficacy, safety, cost-effectiveness and effect on PAI-1 levels of the three low-molecular-weight heparins--enoxaparin, nadroparin and dalteparin. The ESCAPe-END study

BACKGROUND

Comparative data for efficacy and safety between various low-molecular-weight heparins (LMWHs) in patients with unstable angina is not available. The present study was conducted to compare the efficacy, safety, cost-effectiveness and effects on plasminogen activator inhibitor-1 (PAI-1) levels of three LMWHs--enoxaparin, nadroparin and dalteparin.

METHODS

The study was a prospective, randomized, comparative, open with blinded endpoints (PROBE design) assessment with a 30-day follow-up. The primary endpoint of efficacy was a composite of cardiovascular death, myocardial infarction, recurrent angina and need for intervention. Cost-effectiveness was calculated by calculating the incremental cost-effectiveness ratio. Plasma PAI-1 levels were estimated by ELISA.

RESULTS

A total of 150 patients were available for intention-to-treat analysis. There was no significant difference at 30 days in the primary endpoint or in any of the individual components in the three groups. The secondary endpoint of silent ischemia was also not significantly different. Adverse events were similar in the three groups. The PAI-1 levels were not significantly different in the three groups. The total cost of treatment in the three groups was similar.

CONCLUSION

Any of the three LMWHs evaluated in this study were similar with respect to efficacy, safety, PAI-1 levels and cost-effectiveness.

Genotypic diversity in a localized population of Ralstonia solanacearum as revealed by random amplified polymorphic DNA markers

AIMS

To assess genotypic diversity within Ralstonia solanacearum isolates of a single field.

METHODS AND RESULTS

A total of 44 field isolates and 22 in vitro generated clones of R. solanacearum were studied for genotypic diversity by random amplified polymorphic DNA (RAPD) technique. Genomic DNA of these isolates and clones was extracted by proteinase-K-SDS lysis mini-prep method. RAPD analysis was done with 30 decamer primers. The data were analysed using NTSYSpc 2.02h software. Forty-two out of 44 field isolates and all the clonal isolates were identified as distinct genotypes at 70% similarity level.

CONCLUSION

Very high level of genome variability was observed within the field and clonal isolates of R. solanacearum. This might be a reason for the wide host range of this bacterium and for quick breakdown of wilt resistance in host plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results suggest that it would be difficult to design specific diagnostic protocol for R. solanacearum even for a localized population and to breed cultivars with broad-spectrum resistance.

Study design and rationale of a mock phase I trial as an educational tool for clinical pharmacology residents

OBJECTIVE

To invite comments and suggestions from the phase I trialists, the world over, on the design and rationale provided by us for conducting a mock phase I trial for training clinical pharmacology residents.

METHODS

The trial will be conducted by clinical pharmacology residents of the Post Graduate Institute of Medical Education and Research. After a thorough evaluation of Preclinical toxicity data of a pharmaceutical product provided by a dummy pharmaceutical firm, a randomized, double-blind, placebo controlled, parallel group design with dose escalation of the product will be carried out. A single dose administration will be followed by monitoring the participants for 24 h and again at one week. After obtaining results of the previous group, the next higher dose will be administered. Evaluation of the learners will be done by two independent teachers who will mark them for actual conduct of the study and writing a report of the study. Subsequently, we will try to publish the results of the mock trial and invite further comments.

CONCLUSIONS

This trial designed primarily for training purposes will be instrumental in equipping the residents with the expertise for conducting phase I trials.

A meta-analysis of clinical trials of paclitaxel- and sirolimus-eluting stents in patients with obstructive coronary artery disease

AIM

This meta-analysis was conducted to compare the effects of drug (paclitaxel and sirolimus)-eluting stents with bare metal stents on major adverse cardiac events, restenosis rates and late loss of arterial lumen diameter in patients with obstructive coronary artery disease.

METHODS

Randomized, controlled clinical trials comparing sirolimus- and paclitaxel-eluting stents with bare metal stents were identified through electronic and manual search. Fixed effects method of Mantel-Haenszel and random effects method of DerSimonian and Laird were used for computing the pooled odds ratio (OR) and 95% confidence intervals (CI) for major adverse cardiac events and restenosis rates. Standardized mean difference with 95% CI was calculated for late-loss of arterial lumen diameter.

RESULTS

A total of 13 studies were included in the meta-analysis. As compared with bare metal stents, the use of sirolimus- and paclitaxel-eluting stents significantly reduced the major adverse cardiac events (pooled OR 0.35; 95% CI 0.24-0.50), restenosis rates (pooled OR 0.27; 95% CI 0.15-0.47), and late loss of arterial lumen diameter (mean difference 0.57 mm, 95% CI 0.49-0.68).

CONCLUSION

Paclitaxel- and sirolimus-eluting stents significantly reduced the incidence of major adverse cardiac events, restenosis rates, and late loss of arterial lumen diameter as compared with bare metal stents.

Azygos continuation of interrupted inferior vena cava in association with sick sinus syndrome

Various diagnostic and therapeutic procedures of the right side of the heart and the systemic venous system have increased the need for ready access to the inferior vena cava (IVC) through the transfemoral route. Anatomical variations or obstruction of the IVC can make these procedures difficult. The case of 47 year old woman with an interrupted infrahepatic IVC with azygos continuation accompanied by sick sinus syndrome and a structurally normal heart is reported. Negotiating a temporary pacing lead from the IVC to the right atrium was difficult. Ultimately, the lead took the course from the IVC to azygos vein to superior vena cava to right atrium to right ventricular apex. Permanent VVI pacing through the right subclavian route was uneventful, as the superior vena cava and its tributaries had a normal course. An awareness of the existence of these anomalies before pacing can lead to the use of an alternative route for pacing, which may avoid undue delay of an otherwise urgently needed procedure.

Hyperphosphorylation-induced self assembly of murine tau: a comparison with human tau

Alzheimer's disease-like neurofibrillary pathology is neither seen in rodents nor in transgenic animals expressing the disease causing mutant human APP or mutant human presenilins. Whether the absence of this pathology is due to inability of the murine tau to self assemble into filaments or due to some other factors is not understood. In this study, we compared recombinant murine and human taus in their ability to form filaments by AD-like hyperphosphorylation in vitro. Human and murine taus, 0N4R, were generated as recombinant proteins and phosphorylated with rat brain extract as a source of protein kinases. We found that murine tau could be hyperphosphorylated to similar stoichiometry and manner as human tau. Upon hyperphosphorylation, murine tau was able to self polymerize into bundles of paired helical filament- and straight filament-like morphology. The filaments obtained from self assembly of murine tau closely resembled those formed from identically treated human tau. Moreover, like human tau, 60-70% of murine tau aggregated on hyperphosphorylation.

Changing trends in the hospital management of unstable angina: a drug utilization analysis

OBJECTIVE

The current study was designed to investigate drug utilization in the management of unstable angina in India and to examine the changing trends in the management of unstable angina over the past 4 years.

METHODS

We conducted a prescription survey to examine the use of antianginal drugs in patients with unstable angina in a tertiary care Indian hospital. The use of concurrent medications such as antidiabetic, antihypertensive and lipid-lowering agents was also examined. This study results were compared with a similar study done in this institute 4 years earlier.

RESULTS

A total of 159 consecutive prescriptions were evaluated. Aspirin (86%), nitroglycerin infusion (77%) and low-molecular weight heparins (93%) were the most frequently prescribed drugs. Enoxaparin accounted for 76% of the total LMWH use. One of the heparins was used by 92% of all patients, angiotensin-converting enzyme inhibitors (ACEIs) and beta-blockers by 70% and 67%, respectively. Lipid-lowering agents (57%), antidiabetic agents (16%) and antianxiety agents (33%), in addition to antianginals, were also frequently co-administered. Time trend analysis showed that the use of unfractionated heparin fell from 35% to 10% and the use of ACEIs and enoxaparin increased from 17% to 70% and from 51% to 71%, respectively.

CONCLUSIONS

The study showed that unfractionated heparin is less frequently used in the treatment of unstable angina than in the past and that ACEIs are preferred to calcium channel blockers. Enoxaparin remains the most commonly used low-molecular weight heparin for this indication. A variety of low-molecular weight heparins are available for therapy but comparative clinical trials of efficacy and pharmacoeconomic studies comparing the various LMWHs still need to be carried out.

Re-use of explanted DDD pacemakers as VDD- clinical utility and cost effectiveness

Re-use of DDD pulse generators explanted from patients died of unrelated causes is associated with an additional cost of two transvenous leads if implanted as DDD itself, and high rate of infection according to some studies. We studied the clinical and economical aspects of reutilization of explanted DDD pacemakers programmed to VDD mode. Out of 28 patients who received VDD pacemaker during the period, October 2000- September 2001 in the Department of Cardiology, PGIMER, Chandigarh, 5 poor patients were implanted with explanted DDD pulse generators programmed to VDD mode. Each implantation was planned and carried out according to a standard protocol. The age ranged from 45 to 75 (mean-61) years. The indications for pacing were complete heart block (4) and second degree AV block (1). The clinical profile, costs and complications, if any were noted and followed up at regular intervals. The results were compared with patients who received new DDD pulse generators during this period. The additional cost for the atrial lead was not required in these patients. None of these patients had any local site infection. Compared to the two-lead system, the single lead system provided more rapid implantation and minimized complications associated with placement of an atrial lead. The explanted DDD pacemaker can be safely reused as VDD mode with same efficacy in selected patient population. This is associated with lower cost and complications compared to reimplantation as DDD itself.

Estrogen potentiates the combined effects of transforming growth factor-beta and tumor necrosis factor-alpha on adult human osteoblast-like cell prostaglandin E2 biosynthesis

Reports that estrogen treatment modulates arachidonic acid metabolism by bone and bone cells are found in the literature. However, conflicting indications of the relationship that exists between estrogen and arachidonic acid metabolism emerge from the analysis of those reports. The present studies were undertaken to determine if estrogen effected the production of prostaglandins (PG) in human osteoblast-like (hOB) cell cultures derived from adults, under basal or cytokine-stimulated conditions. A 48-hour estrogen pretreatment did not modify hOB cell PG biosynthesis on a qualitative basis, and PGE2 formation predominated under all tested conditions. Estrogen pretreatment did lead to increased PGE2 production in specimens stimulated conjointly with transforming growth factor-beta1 and tumor necrosis factor-alpha ( p < 0.001). No changes in PGE2 production were observed in estrogen pretreated specimens stimulated singly with either tested cytokine, nor in samples in which either TGFbeta or TNF was replaced by interleukin-1beta. Anti-estrogen (ICI 164,384) inclusion prevented the estrogen-dependent increase in PGE2 production in the TGFbeta plus TNF-stimulated samples. These results suggest that an estrogen effect on bone cell prostaglandin biosynthesis may be most evident and significant under conditions in which the cells are exposed to multiple osteotropic cytokines, a condition that applies during the bone remodeling process.

Effect of different aspirin doses on platelet aggregation in patients with stable coronary artery disease

BACKGROUND

Aspirin is widely used as an antiplatelet agent in the primary and secondary prevention of cardiovascular disease. In order to spare prostacyclin formation and reduce gastrointestinal side-effects, very low doses of aspirin have been introduced. However, it remains unclear whether these low doses are equally effective with respect to inhibition of platelet aggregation.

AIMS

In a randomized, controlled study in 60 patients with stable coronary artery disease, the effects on platelet aggregation of five doses (50, 80, 100, 162.5 and 325 mg) of aspirin, which are widely used in clinical practice, given for 70 days, were investigated. Two reagents, adenosine diphosphate (ADP) and epinephrine, were used to induce platelet aggregation in platelet-rich plasma. An age- and sex-matched group of people without coronary artery disease served as the control.

RESULTS

ADP- and epinephrine-induced platelet aggregation was 78.2 +/- 12.8% and 76.7 +/- 15.5% of maximum aggregation in the control group. Aspirin inhibited platelet aggregation in a dose-dependent manner. Minimum platelet aggregation was observed at a dose of 325 mg aspirin (27.5 +/- 17.4% with ADP). Doses of 50 and 80 mg aspirin were much less effective in inhibiting platelet aggregation (59.1 +/- 11.4% and 50.3 +/- 12.1% with ADP, respectively). Doses of 100 and 162.5 mg aspirin produced significantly greater inhibition of platelet aggregation than lower doses (36.2 +/- 11.7% and 38.5 +/- 19.8% platelet aggregation with ADP, respectively).

CONCLUSION

Our results demonstrate that doses of aspirin less than 100 mg are not as effective at inhibiting platelet aggregation as doses greater than 100 mg.

Prehospital delay in patients hospitalized with acute myocardial infarction in the emergency unit of a North Indian tertiary care hospital

BACKGROUND

Prompt treatment of patients presenting with acute myocardial infarction decreases the incidence of death from early arrhythmia, and maximizes the potential benefit of thrombolytic therapy. Prehospital delay has been identified as a major obstacle to the widespread use of thrombolytic therapy. The aim of the present study was to examine the extent of, and factors associated with, delay in seeking medical care (usually thrombolytic therapy) in patients with acute myocardial infarction.

METHODS AND RESULTS

The study was conducted in patients visiting the medical emergency unit of the Nehru Hospital, Post Graduate Institute of Medical Education and Research, Chandigarh. A total of 104 patients diagnosed with acute myocardial infarction were interviewed using a pre-designed proforma. Pain-to-door, and door-to-drug times, were the main outcome measures. The corrected mean (SEM) and median (range) pain-to-door times were 8.5 (0.8) hours and 5.2 (0.5-24) hours, respectively. Out of 104 patients, 38 did not receive thrombolytic therapy. In those who did not receive thrombolytic therapy, prior therapy at local health centers, lack of knowledge of symptoms, and transportation problems were the main reasons for hospital delay. The mean (SEM) and median (range) of door-to-drug times were 1.2 (0.1) hours and 1 (0.2-3.5) hours, respectively.

Isolation and expression analysis of salt stress-associated ESTs from contrasting rice cultivars using a PCR-based subtraction method

Salt stress adversely affects the growth of rice plants. To understand the molecular basis of salt-stress response, four subtracted cDNA libraries were constructed employing specific NaCl-stressed tissues from salt-tolerant (CSR 27 and Pokkali) and salt-sensitive (Pusa basmati 1) rice cultivars. An efficient PCR-based cDNA subtraction method was employed for the isolation of the salt-stress responsive cDNA clones. In all, 1,266 cDNA clones were isolated in the course of this study, out of which 85 clones were end-sequenced. Database search of the sequenced clones showed that 22 clones were homologous to genes that have earlier been implicated in stress response, 34 clones were novel with respect to their function and six clones showed no homology to sequences in any of the public database. Northern analysis showed that the transcript expression pattern of selected clones was variable amongst the cultivars tested with respect to stress-regulation.

Maternal and perinatal outcome in rheumatic heart disease

OBJECTIVES

To study the maternal and perinatal outcome of pregnancies complicated by rheumatic heart disease.

METHODS

A retrospective study was carried out in the cardio-obstetric clinic of the Postgraduate Institute of Medical Education and Research, Chandigarh (India) over a period of 13 years (1987-1999) involving 486 pregnant patients with rheumatic heart disease. Maternal and perinatal outcome was reviewed.

RESULTS

Three hundred and four patients (63.3%) had single valve involvement and mitral stenosis was the most predominant lesion (89.2%). One hundred and seventy one (38.6%) patients had undergone surgical correction prior to the onset of pregnancy. One hundred and thirteen patients (22.6%) were identified as NYHA class III-IV. Mitral valvotomy was performed during pregnancy in 48 patients. The incidence of preterm birth and small for gestational age newborns was 12% and 18.2%, respectively. There were 10 maternal deaths, of which eight patients were NYHA III and IV.

CONCLUSIONS

Rheumatic heart disease in pregnancy is associated with significant maternal and perinatal morbidity in NYHA class III-IV patients.

Arabidopsis thaliana Hsp100 proteins: kith and kin

Arabidopsis thaliana, the first plant for which the entire genome sequence is available, was also among the first plant species from which Hsp100 proteins were characterized. The Athsp101 complementary DNA (cDNA) corresponds to the gene identification At1g74310 in the Arabidopsis genome sequence. Analysis of the genome revealed 7 additional proteins that are variably homologous with At1g74310 throughout the entire amino acid sequence and significant similarities or identities in the signature sequences conserved among Hsp100 proteins. Although AtHsp101 is cytoplasmic, 5 of the 7 related proteins have predicted plastidial localization signals. This complete description of the AtHsp100 family sets the stage for future research on expression and function.

Arabidopsis thaliana Hsp100 proteins: kith and kin

Arabidopsis thaliana, the first plant for which the entire genome sequence is available, was also among the first plant species from which Hsp100 proteins were characterized. The Athsp101 complementary DNA (cDNA) corresponds to the gene identification At1g74310 in the Arabidopsis genome sequence. Analysis of the genome revealed 7 additional proteins that are variably homologous with At1g74310 throughout the entire amino acid sequence and significant similarities or identities in the signature sequences conserved among Hsp100 proteins. Although AtHsp101 is cytoplasmic, 5 of the 7 related proteins have predicted plastidial localization signals. This complete description of the AtHsp100 family sets the stage for future research on expression and function.

A cardiac evoked response algorithm providing automatic threshold tracking for continuous capture verification: a single-center prospective study

BACKGROUND

The AutoCapture algorithm as implemented in Regency and Microny pacemakers (Pacesetter Inc., Sylmar, CA, USA) provides beat-by-beat monitoring of capture based on proper detection of the evoked response, provides high output back-up pulse when loss of capture occurs, performs periodic threshold evaluations and acquires the capture threshold data in a time-based event counter for later retrieval. The safety and efficacy of this algorithm was prospectively evaluated at a tertiary care hospital of north India.

METHODS AND RESULTS

Fifty-four patients (38 males, mean age 66+/-13 years) received a ventricular pacemaker model Regency SC+ with low polarization bipolar lead for high-grade atrioventricular block (n=42) and sick sinus syndrome (n=12). Evoked response and polarization signal were assessed initially at 24 hours postimplant, and follow-up measurements were systematically conducted at week 1 and months 1, 3 and 6. Further evaluation of eligible patients was performed at 6-monthly intervals. Lead implantation parameters were optimum in all patients. At 6 months, the algorithm was functional in 51 patients. The pacing threshold increased to 0.89+/-0.36 V (p<0.001) in the first month and stabilized thereafter. Significant saving of energy was accomplished by a constant output safety margin of 0.3 V instead of the traditional 100%. While the evoked response signal remained stable throughout the study period, the potential signal increased significantly from 0.6+/-0.7 mV to 1.0+/-0.6 mV (p<0.001) in the first month and remained steady subsequently. Back-up pacing in the event of exit block was confirmed in all 25 patients who underwent a 24-hour Holter test. Based on the suggested sense margins, ventricular undersensing was observed in 7 (28%) patients, the majority of whom had competitive cardiac rhythms. An elderly patient with pneumonic illness succumbed to pulmonary embolism at 6 months.

CONCLUSIONS

This large single-center experience on AutoCapture demonstrates the success of this algorithm in low-energy ventricular pacing without compromising the patient's safety.

Involvement of nitric oxide in the antiaggregatory effect of enalapril

This study was conducted to examine the effects of single dose enalapril (1.6 mg/kg) on platelet aggregation alone and after an intravenous bolus dose of the nitric oxide synthase (NOS) inhibitor N-nitro-L-arginine (L-NNA; 40 mg/kg). Blood samples were collected before and 1, 2 and 6 h after the administration of drugs in rhesus monkeys. Enalapril was administered via a nasogastric tube while L-NNA was administered by the intravenous route. Platelet aggregation was stimulated with adenosine diphosphate (ADP) in platelet rich plasma (PRP). Enalapril significantly inhibited platelet aggregation with a peak effect at 6 h. Upon administration of L-NNA, there was a significant increase in the percentage of platelet aggregation. This effect was partially antagonized by enalapril. The present study demonstrates that enalapril may possess antiaggregatory effects, which may be mediated via nitric oxide mechanisms.

Open versus percutaneous dilatational tracheostomy: efficacy and cost analysis

The economic advantages of percutaneous dilatational tracheostomies versus open tracheostomies in the operating room have been thoroughly evaluated. We are now reporting our comparison of the costs and charges of percutaneous dilatational tracheostomies with those of open bedside tracheostomies at our institution. The current literature comparing the two open techniques and the percutaneous method of placing tracheostomies was reviewed and the charges and costs for these procedures at our institution were compared. Patients were placed into one of three groups for analysis: open tracheostomies in the operating room (Group I), open tracheostomies in the intensive care unit (Group II), and percutaneous dilatational tracheostomies in the intensive care unit (Group III). Based on our own experience and a literature review it is evident that all three approaches to tracheostomies are safe. Economic analysis showed a savings of $180 in cost per procedure and a $658 savings in charges per procedure for the open method at the bedside when compared with the percutaneous method at the bedside. The professional fee for bronchoscopy was not included in this calculation; including this would lead to greater savings with the open method over the percutaneous method. Open tracheostomy in the operating room increased costs over the bedside procedure by $2194 and increased charges by $2871. For the 150 to 180 tracheostomies done each year at our institution utilization of the open technique at the bedside results in a cost savings of approximately $31,500 and a charge savings of $109,000 compared with the percutaneous dilatational tracheostomy. Both the open bedside and percutaneous dilatational methods are reasonable and safe options. However, the open bedside tracheostomy is a better utilization of resources and is more cost effective, and it is the procedure of choice at our institution.

A meta-analysis of controlled clinical trials comparing low-molecular weight heparins with unfractionated heparin in unstable angina

BACKGROUND

Unfractionated heparin has been used extensively for the treatment of unstable angina/non-Q wave myocardial infarction but it has several disadvantages. Low-molecular weight heparins are now recommended although they are 3-5 times costlier than unfractionated heparin since they are convinient to administer and do not require activated thromboplastin time monitoring. Whereas enoxaparin, a low-molecular weight heparin, has been demonstrated to be superior to unfractionated heparin, the results of other low-molecular weight heparins have not been so convincing.

METHOD AND RESULTS

Through manual, MEDLINE and EMBASE search, we identified five randomized trials (excluding enoxaparin trials) that compared low-molecular weight heparins with unfractionated heparin in unstable angina. The prespecified efficacy end point of interest included a composite of death, myocardial infarction, recurrent angina and urgent revascularization. The safety end point was taken as a composite of major hemorrhage, minor hemorrhage, thrombocytopenia, allergic reaction and any other adverse event. We calculated odds ratio (95% confidence interval) for each trial for the composite end point, and the pooled odds ratio (95%) confidence interval) was calculated using two established methods of meta-analysis, the Mantel-Haenszel-Peto method and the DerSirmonian-Laird method. Both the methods yielded similar odds ratio (95% confidence interval). Separate odds ratio were calculated for efficacy and safety end points. There was a nonsignificant reduction in the incidence of the composite efficacy end point: the odds ratio (95% confidence interval) was 0.83 (0.70-0.99: p=0.08). The odds ratio (95% confidence interval) for the safety data was 0.78 (0.69-1.26: p=0.33).

CONCLUSIONS

No statistically significant difference was observed when the efficacy and safety of low-molecular weight heparins were compared with those of unfractionated heparin. A cost-effectiveness analysis of low-molecular weight heparins versus unfractionated heparin must be done urgently to establish more firmly the place of low-molecular weight heparins in the management of unstable angina.

Secondary lymphoma of the heart presenting as recurrent syncope

A 12-year-old male child presented with recurrent syncope. Ventricular tachycardia was noted on the electrocardiogram. Transthoracic echocardiogram revealed a homogeneous tumor mass in the right ventricular cavity with extension into the outflow region. Left cervical lymph node biopsy confirmed the diagnosis of non-Hodgkin's lymphoma. The tumor resolved completely with chemotherapy without surgical intervention.

A randomized trial to compare the efficacy, safety, cost and platelet aggregation effects of enoxaparin and unfractionated heparin (the ESCAPEU trial)

OBJECTIVE

To compare the efficacy, safety, cost and effects on platelet aggregation of unfractionated heparin and low-molecular weight heparin in unstable angina patients.

PATIENTS AND METHODS

Ninety-three patients with unstable angina were randomized to receive either unfractionated heparin (UFH) or enoxaparin in an open design clinical trial with blinded end point evaluation. The effects of the heparins on platelet aggregation were also compared.

RESULTS

The composite end point of myocardial infarction, cardiac death, recurrent angina and need for intervention was observed in 62% of patients treated with UFH and in 37% of patients treated with enoxaparin (RR 1.7, 95% CI 0.75 to 3.71, p = 0.04). There was no difference in the frequency or severity of adverse events. A cost-effectiveness analysis showed both the heparins to be similar. Platelet aggregation was inhibited to a greater extent by UFH when compared to enoxaparin.

CONCLUSIONS

Enoxaparin appears to be superior in efficacy to UFH and similar to UFH in safety. No difference in costs was detected in this study. The greater inhibition of platelet aggregation observed in the case of UFH compared to enoxaparin indicates that there may be more bleeding complications with UFH.

Distribution of cells bearing B-cell alloantigen(s) in North Indian rheumatic fever/rheumatic heart disease patients

Numerous investigators have developed monoclonal antibodies against B-cell alloantigen(s) of rheumatic fever. However, the developed monoclonals do not have the same significance in all the populations. We have developed a battery of monoclonals against B-cell alloantigens of North Indian rheumatic fever patients. In the present study, we have used these monoclonals to examine the frequency of rheumatic antigens in 30 patients with recurrence of rheumatic activity (RRA), 30 of rheumatic heart disease (RHD) patients and 50 controls using alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. These patients were examined at the time of registry and after three months follow up. RRA patients showed higher percentage of lymphocyte positive as compare to RHD and controls. Interestingly, on follow-up RRA patients showed significant decline in positive lymphocyte as compare to first visit whereas no such change was observed in RHD patients. There were 90-93% of RRA and RHD patients positive with these monoclonals. A significant age variation of rheumatic cells was also noticed in all groups of rheumatic patients. We conclude that monoclonals raised from the same ethnic population are highly specific and cost effective to use them to develop an easy field test system such as APAAP, to identify the individual at risk, to develop rheumatic fever. It is also suggested that the alloantigen marker may persist through out life and gets activated after recurrence of the disease.

A study of drug utilisation and cost of treatment in patients hospitalised with unstable angina

OBJECTIVE

The current study was designed to investigate drug utilisation in the management of unstable angina in India and to calculate the costs incurred by patients in the treatment of a single episode of unstable angina.

METHODS

We conducted a prescription survey to examine the use of antianginal drugs in patients with unstable angina in a tertiary care Indian hospital. The use of concurrent medications such as antidiabetic, antihypertensive and lipid-lowering agents was also examined. Data on the cost of treatment, investigations, income, and family size were collected from the case histories or direct interviews with the patients/relatives.

RESULTS

A total of 336 consecutive prescriptions were evaluated. Aspirin was the most frequently prescribed drug (98%) followed by nitroglycerin infusion (90%) and enoxaparin (52%). One of the heparins was used by 89% of all patients and beta-blockers by up to 62% of the patients. Besides antianginals, antihypertensive (49%) and antidiabetic (16%) drugs were commonly coadministered. The mean (+/- SD) cost of treatment of a single episode of unstable angina in the hospital was US $494 (+/- 271) against an annual per capita income of US $245. The mean (+/- SD) cost incurred by the patients due to drugs alone during the hospital stay was US $70 (+/- 18) and enoxaparin accounted for 60% of the expenditure due to drugs.

CONCLUSIONS

The results of our study show that low-molecular-weight heparin, enoxaparin, is replacing unfractionated heparin in the treatment of unstable angina. In view of the use of costly new drugs, there is an urgent need for carrying out pharmacoeconomic analysis in developing countries as the treatment of a single episode of unstable angina imparts a considerable economic burden on the patient.