Immune biomarker evaluation of sequential tyrosine kinase inhibitor and nivolumab monotherapies in renal cell carcinoma: the phase I TRIBE trial

Background

Predictive biomarkers for immune checkpoint blockade in the second-line treatment of metastatic renal cell carcinoma (mRCC) are lacking.

Materials and methods

Patients with histologically confirmed RCC who started nivolumab after at least 4 months of tyrosine kinase inhibitors (TKIs) were recruited for this study. Serial tissue and blood samples were collected for immune biomarker evaluation. The primary endpoint was to determine the association of specific T-cell subsets with clinical outcomes tested using Wilcoxon rank sum for clinical benefit rate (CBR) and log-rank test for progression-free survival (PFS).

Results

Twenty patients were included in this trial with a median age of 64 years and followed-up for a median of 12 months. The median PFS for patients who received TKI was 13.8 months, while for those subsequently treated with nivolumab following TKI therapy, the median PFS was 2.6 months. CBR of nivolumab was 20% with two partial responses. Functionally active programmed cell death protein 1+ CD4+ T cells were enriched in non-responders (q = 0.003) and associated with worse PFS on nivolumab (P = 0.04). Responders showed a significant reduction in the effector CD4+T-cell (TEF) fraction compared to non-responders at 3 months on nivolumab (0.40 versus 0.80, P = 0.0005). CD127+CD4+ T cells were enriched in patients who developed immune-related adverse effects (q = 0.003). Using in-house validated multiplex immunohistochemistry for six markers, we measured tumour-associated immune cell densities in tissue samples. Responders to nivolumab showed a significantly higher mean of immune cell densities in tissue samples compared to non-responders (346 versus 87 cells/mm2, P = 0.04).

Conclusions

In this small study, analysis of tissue-based and peripheral blood immune cell subsets predicted clinical outcomes of nivolumab. Further studies are warranted with larger populations to validate these observations.

Barriers and facilitators to health during prison reentry to Miami, FL

BACKGROUND

People face numerous barriers to reentry and community integration following incarceration, and these obstacles manifest themselves as barriers to economic stability, housing security, healthcare, community acceptance, and educational attainment, ultimately leading to poor health. This study aims to understand healthcare needs of reentrants post release within the unique political and service context of Miami Dade County, FL, and seeks to uncover the structural facilitators and barriers to sustaining health during reentry.

METHODS

We report on a subset of data from a larger reentry asset mapping project. We conducted a qualitative thematic analysis based on 12 semi-structured interviews with community stakeholders, including reentrants who were released in the past year (n = 5) and with community providers who have provided support services to returning citizens for at least one year (n = 7). Narratives were coded through an iterative process using NVivo software and were analyzed using the general inductive approach.

RESULTS

Three themes emerged from the analysis: (1) social and structural barriers and facilitators to health during reentry, (2) challenges with medical care following release, and (3) long-term impacts of receiving poor healthcare in prison. Reentrants describe the carceral environment as non-conducive to health and cite an urgent need for systemic change within correctional institutions to promote their well-being. Respondents identified substance use disorder (SUD) treatment, trauma informed therapy, and chronic disease management as the primary healthcare needs of reentrants, and cite social support, stable housing, education, and employment as the key social and structural needs upon release.

CONCLUSION

This study identifies prevalent resource gaps in Miami Dade County during reentry. Respondents advocate for more inclusive governmental housing programs, Medicaid expansion, and more holistic reentry programs to support reentrants. Understanding the barriers and facilitators to health during reentry can inform future interventions to better support reentrants in their transition post-incarceration.

Oxidized mC modulates synthetic lethality to PARP inhibitors for the treatment of leukemia

TET2 haploinsufficiency is a driving event in myeloid cancers and is associated with a worse prognosis in patients with acute myeloid leukemia (AML). Enhancing residual TET2 activity using vitamin C increases oxidized 5-methylcytosine (mC) formation and promotes active DNA demethylation via base excision repair (BER), which slows leukemia progression. We utilize genetic and compound library screening approaches to identify rational combination treatment strategies to improve use of vitamin C as an adjuvant therapy for AML. In addition to increasing the efficacy of several US Food and Drug Administration (FDA)-approved drugs, vitamin C treatment with poly-ADP-ribosyl polymerase inhibitors (PARPis) elicits a strong synergistic effect to block AML self-renewal in murine and human AML models. Vitamin-C-mediated TET activation combined with PARPis causes enrichment of chromatin-bound PARP1 at oxidized mCs and γH2AX accumulation during mid-S phase, leading to cell cycle stalling and differentiation. Given that most AML subtypes maintain residual TET2 expression, vitamin C could elicit broad efficacy as a PARPi therapeutic adjuvant.

Metabolomics to understand placental biology: Where are we now?

Metabolomics, the application of analytical chemistry methodologies to survey the chemical composition of a biological system, is used to globally profile and compare metabolites in one or more groups of samples. Given that metabolites are the terminal end-products of cellular metabolic processes, or 'phenotype' of a cell, tissue, or organism, metabolomics is valuable to the study of the maternal-fetal interface as it has the potential to reveal nuanced complexities of a biological system as well as differences over time or between individuals. The placenta acts as the primary site of maternal-fetal exchange, the success of which is paramount to growth and development of offspring during pregnancy and beyond. Although the study of metabolomics has proven moderately useful for the screening, diagnosis, and understanding of the pathophysiology of pregnancy complications, the placental metabolome in the context of a healthy pregnancy remains poorly characterized and understood. Herein, we discuss the technical aspects of metabolomics and review the current literature describing the placental metabolome in human and animal models, in the context of health and disease. Finally, we highlight areas for future opportunities in the emerging field of placental metabolomics.

227 Multiple Outbreak Of SARS-COVID-19 In Surgical Wards at The Tertiary Hospital

Background

Since the second surge of SARS-COVID-19 on 18th of September, additional several measures were introduced, and pathways created in order to execute safe surgical practices and protect both patients and staff from SARS-COVID-19. Despite these measures, there have been reported cases of outbreaks in various parts of UK amongst patients and clinical staff.

Method

Three outbreaks in the past 6 weeks (10, September 2020 to 21, October 2020) were reported in our surgical wards and we compiled the timing, initial source, number of affected individuals and immediate management steps taken.

Results

Following the first outbreak on wards, 28-day surveillance helped us understand responsible variants. Several staff members were found walking out of hospital, in groups once they had removed their PPEs. Communal lunching with inadequate social distancing, attending work with symptoms (albeit atypical for COVID), sharing cars to/from work or not wearing PPE correctly were highlighted in the subsequent investigations. The reduction in number of affected individuals during the last two incidents reflected a degree of efficacy of the implemented preventative measures, which were reviewed again following the subsequent incidents.

Conclusions

In the present climate, a robust and prompt response to outbreaks is required. Continual iteration with regards to the need for PPE, adequate social distancing and avoiding over-crowding in communal areas is paramount to reduce the probability of ward outbreaks and inter-professional transmission. Asymptomatic staff testing, particularly in high-risk areas could also be considered but would require adequate laboratory capacity and rapid turnaround of test results.

Epigenetic Regulation of Genomic Stability by Vitamin C

DNA methylation plays an important role in the maintenance of genomic stability. Ten-eleven translocation proteins (TETs) are a family of iron (Fe²⁺) and α-KG -dependent dioxygenases that regulate DNA methylation levels by oxidizing 5-methylcystosine (5mC) to generate 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). These oxidized methylcytosines promote passive demethylation upon DNA replication, or active DNA demethylation, by triggering base excision repair and replacement of 5fC and 5caC with an unmethylated cytosine. Several studies over the last decade have shown that loss of TET function leads to DNA hypermethylation and increased genomic instability. Vitamin C, a cofactor of TET enzymes, increases 5hmC formation and promotes DNA demethylation, suggesting that this essential vitamin, in addition to its antioxidant properties, can also directly influence genomic stability. This review will highlight the functional role of DNA methylation, TET activity and vitamin C, in the crosstalk between DNA methylation and DNA repair.

Society of pediatric liver transplantation: Current registry status 2011-2018

BACKGROUND

SPLIT was founded in 1995 in order to collect comprehensive prospective data on pediatric liver transplantation, including waiting list data, transplant, and early and late outcomes. Since 2011, data collection of the current registry has been refined to focus on prospective data and outcomes only after transplant to serve as a foundation for the future development of targeted clinical studies.

OBJECTIVE

To report the outcomes of the SPLIT registry from 2011 to 2018.

METHODS

This is a multicenter, cross-sectional analysis characterizing patients transplanted and enrolled in the SPLIT registry between 2011 and 2018. All patients, <18 years of age, received a first liver-only, a combined liver-kidney, or a combined liver-pancreas transplant during this study period.

RESULTS

A total of 1911 recipients from 39 participating centers in North America were registered. Indications included biliary atresia (38.5%), metabolic disease (19.1%), tumors (11.7%), and fulminant liver failure (11.5%). Greater than 50% of recipients were transplanted as either Status 1A/1B or with a MELD/PELD exception score. Incompatible transplants were performed in 4.1%. Kaplan-Meier estimates of 1-year patient and graft survival were 97.3% and 96.6%. First 30 days of surgical complications included reoperation (31.7%), hepatic artery thrombosis (6.3%), and portal vein thrombosis (3.2%). In the first 90 days, biliary tract complications were reported in 13.6%. Acute cellular rejection during first year was 34.7%. At 1 and 2 years of follow-up, 39.2% and 50.6% had normal liver tests on monotherapy (tacrolimus or sirolimus). Further surgical, survival, allograft function, and complications are detailed.

Concomitant back pain as a predictor of outcome after single level lumbar micro-decompressive surgery - A study of 995 patients

Objective

To determine if preoperative leg pain and low back pain severity affected postoperative outcome.

Method

Prospectively collected Spine-Tango data was analysed for 995 consecutive patients who underwent a primary, single level, lumbar micro-decompression/microdiscectomy at a single tertiary spinal centre.

Result

At 3 months, 72% of patients were satisfied with the outcome of surgery. Pre-operative low back pain was a significant predictor of poor outcome (P < 0.01).

Conclusion

Our study has shown that patients with a low back pain VAS of 6 or more have a significantly greater chance of a poor outcome following primary lumbar microdecompressive/microdiscectomy surgery.

Salmon gill poxvirus disease in Atlantic salmon fry as recognized by improved immunohistochemistry also demonstrates infected cells in non-respiratory epithelial cells

Gill diseases cause serious losses in farming of Atlantic salmon and the number of agents involved increases. Salmon gill poxvirus (SGPV) and the gill disease in causes where SGPV apparently was the only disease-causing agent were initially characterized. Recently, it was further shown that SGPV can be a common denominator in widely different multifactorial gill diseases. Here, we present the challenge of diagnosing gill disease with SGPV in salmon fry of 0,3-5 grams. Apoptosis of gill lamellar epithelial cells and hemophagocytosis was also observed in fry similar to findings in smolts and grow-out fish. Using our newly developed immunohistochemistry method, we further demonstrate that some of the apoptotic epithelial cells covering the oral cavity were positive for SGPV. Thus, SGPV is not restricted to respiratory epithelium alone and may infect the fish at very early life stages. Furthermore, as the cases examined here are from Norway, Faroe Island and Scotland, we show that SGPV is more widespread than previously reported.

[Mania induced by antibiotic therapy]

We report two cases of adults who developed mania after taking the antibiotic clarithromycin. Clarithromycin is a frequently used antibiotic, but it can lead to a rare but significant psychiatric complication in the form of a manic episode. Mania is commonly associated with bipolar disorder, but the causes can be pharmacological, metabolic or neurologic, particularly when it occurs in patients who themselves or whose families have no past history of psychiatric illness. New-onset mania calls for detailed clinical and laboratory testing and neuro-imaging so that somatic causes can be ruled out. It is important that the currently used medication is included in the differential diagnosis of mania. The first step in treatment is to discontinue the antibiotic therapy. The pharmacological treatment for mania caused by antibiotic therapy is largely the same as for mania in bipolar disorder; this means starting with anti-manic and anti-psychotic medication and providing a structured and calming environment. Most cases of pharmacologically induced mania are resolved if the aetiology is determined and treated. Mania that has pharmacological causes generally does not require prophylactic mood-stabilising treatment. Nevertheless, a psychiatric follow-up is advisable. If these steps are taken, the prognosis is favourable.

Brain Structural and Vascular Anatomy Is Altered in Offspring of Pre-Eclamptic Pregnancies: A Pilot Study

BACKGROUND AND PURPOSE

Pre-eclampsia is a serious clinical gestational disorder occurring in 3%-5% of all human pregnancies and characterized by endothelial dysfunction and vascular complications. Offspring born of pre-eclamptic pregnancies are reported to exhibit deficits in cognitive function, higher incidence of depression, and increased susceptibility to stroke. However, no brain imaging reports exist on these offspring. We aimed to assess brain structural and vascular anatomy in 7- to 10-year-old offspring of pre-eclamptic pregnancies compared with matched controls.

MATERIALS AND METHODS

Offspring of pre-eclamptic pregnancies and matched controls (n = 10 per group) were recruited from an established longitudinal cohort examining the effects of pre-eclampsia. Children underwent MR imaging to identify brain structural and vascular anatomic differences. Maternal plasma samples collected at birth were assayed for angiogenic factors by enzyme-linked immunosorbent assay.

RESULTS

Offspring of pre-eclamptic pregnancies exhibited enlarged brain regional volumes of the cerebellum, temporal lobe, brain stem, and right and left amygdalae. These offspring displayed reduced cerebral vessel radii in the occipital and parietal lobes. Enzyme-linked immunosorbent assay analysis revealed underexpression of the placental growth factor among the maternal plasma samples from women who experienced pre-eclampsia.

CONCLUSIONS

This study is the first to report brain structural and vascular anatomic alterations in the population of offspring of pre-eclamptic pregnancies. Brain structural alterations shared similarities with those seen in autism. Vascular alterations may have preceded these structural alterations. This pilot study requires further validation with a larger population to provide stronger estimates of brain structural and vascular outcomes among the offspring of pre-eclamptic pregnancies.

Recent advances in the synthesis of natural multifunctionalized decalins

This review highlights recent innovative synthetic strategies developed for the stereoselective construction of natural complex decalin systems. It offers an insight into various synthetic targets and approaches and provides information for developments within the area of natural products as well as synthetic methodology.

Respiratory effects in children from passive smoking of cigarettes and narghile: ISAAC Phase Three in Syria

BACKGROUND

The association between environmental tobacco smoke (ETS) and asthma symptoms is well documented, but a causal relationship is inconclusive. International Study of Asthma and Allergies in Childhood (ISAAC) Phase Three was the first to report a dose-response relationship between current wheezing and exposure to parental cigarette smoke. As exposure of children to water pipe (narghile) smoke is of concern in Syria, in the ISAAC Phase Three Tartous Centre we also examined the role of parental smoking of the narghile.

METHODS

Parents of children aged 6-7 years completed core written questionnaires about the prevalence of symptoms, and an environmental questionnaire for other risk factors, including parental cigarette smoking. We added questions about narghile to the questionnaire.

RESULTS

Among 2 734 pupils (49% females) surveyed, we found an association between exposure to ETS of the mother smoking cigarette or narghile and ever wheezing, nocturnal cough and severe wheeze; however, the strongest association was found when the mother smoked narghile. Mother smoking narghile was also associated with exercise wheeze. Father smoking narghile, but not cigarettes, was associated with nocturnal cough, severe wheeze and exercise wheeze. The association with current wheeze became significant when mother smoked both cigarettes and narghile; however, the effect was addititive and not synergic.

CONCLUSION

We recommend that international studies investigating ETS include questions on narghile smoking.

Posttransplant metabolic syndrome in the withdrawal of immunosuppression in Pediatric Liver Transplant Recipients (WISP-R) pilot trial

Posttransplant metabolic syndrome (PTMS)-obesity, hypertension, elevated triglycerides, low HDL and glucose intolerance-is a major contributor to morbidity after adult liver transplant. This analysis of the Withdrawal of Immunosuppression in Pediatric Liver Transplant Recipients (WISP-R) pilot trial is the first prospective study of PTMS after pediatric liver transplant. Twenty children were enrolled in WISP-R, at median age 8.5 years (IQR 6.4-10.8), and weaned from calcineurin-inhibitor monotherapy. The 12 children who tolerated complete immunosuppression withdrawal were compared to matched historical controls. At baseline, 45% of WISP-R subjects and 58% of controls had at least one component of PTMS. Calcineurin-inhibitor withdrawal in the WISP-R subjects did not impact the prevalence of PTMS components compared to controls. At 5 years, despite weaning off of immunosuppression, 92% of the 12 tolerant WISP-R subjects had at least one PTMS component and 58% had at least two; 33% were overweight or obese, 50% had dyslipidemia, 33% glucose intolerance and 42% systolic hypertension. Overweight/obesity increased the risk of hypertension in all children. Compared to controls, WISP-R tolerant subjects had similar GFR at baseline but did have higher GFR at 2, 3 and 4 years. Further study of PTMS and immunosuppression withdrawal after pediatric liver transplant is warranted.

Profile changes after conventional and chin shield genioplasty

INTRODUCTION

The aim of this study was to compare the profile changes after conventional and chin shield genioplasty.

MATERIAL AND METHOD

20 patients with retruded chin were randomly allocated to two different groups. The experimental group had chin shield osteotomy with interposition of hydroxyapatite collagen graft soaked in platelet rich plasma, while the controls had a conventional genioplasty. The outcome variables evaluated were lip seal, chin thickness, mandibular base length, SNB, labiomental angle, anterior lower facial height, transverse chin shift, and complications.

RESULTS

There was an increase in chin thickness among all, but a significant increase in anterior lower facial height was seen in the experimental group only. There was no statistically significant difference in satisfaction score in both groups.

CONCLUSION

Chin shield genioplasty provides horizontal as well as vertical lengthening of chin without deepening of the mentolabial fold. Hydroxyapatite collagen bone graft and platelet rich plasma promote healing, induce bone formation and reduce bone resorption.

Unilateral temporomandibular joint ankylosis with contralateral aplasia

The temporomandibular joint (TMJ) is considered as one of the complex joints of the human body. Mandibular condylysis is distinguished from condylar aplasia by its non-association with aural/facial anomalies, and also as normal development appears to proceed until the lytic event occurs. It is further distinguished from primary and secondary condylar hypoplasia by the following: Absence of condyle rather than it being small, the normal development appears to proceed until the lytic event occurs, and its non-association with aural/facial anomalies or temporomandibular ankylosis. In the present report, a patient with a unilateral missing mandibular condyle with contralateral TMJ ankylosis is presented and the treatment is outlined and discussed.

Liver transplantation followed by allogeneic hematopoietic stem cell transplantation for atypical mevalonic aciduria

Mevalonic aciduria because of mutations of the gene for mevalonate kinase causes limited synthesis of isoprenoids, the effects of which are widespread. The outcome for affected children is poor. A child with severe multisystem manifestations underwent orthotopic liver transplantation at age 50 months for the indication of end-stage liver disease. This procedure corrected liver function and eliminated portal hypertension, and the patient showed substantial improvement in neurological function. However, autoinflammatory episodes continued unabated until hematopoietic stem cell transplantation was performed at 80 months. Through this complex therapy, the patient now enjoys a high quality of life without significant disability.

Health status in young adults two decades after pediatric liver transplantation

We conducted a cross-sectional study of patients who underwent pediatric liver transplant (LT) between 1988 and 1992 to evaluate long-term health status. Survivors completed socio-demographic, medical and Health-Related Quality of Life (HRQOL) surveys by mail including the SF-36v2, PedsQL™4.0 Generic Core Scale, PedsQL™ Cognitive Functioning Scale and PedsQL™3.0 Transplant Module. SF-36 scores were converted to SF6D-based utilities and risk factors for lower outcomes were assessed. Eighty-five of 171 patients had survived. Fifty-six were contacted with a response rate of 66%. Median age at LT was 0.86 years (IQR 0.58-3.0) and 64.3% had biliary atresia. Mean age at survey was 23.0 ± 4.4 years: 62% attended college, 68% lived with parents and 80% of those over 23 were employed. Patient health utilities were lower than norms (0.75 ± 0.12 vs. 0.82 ± 0.18, p < 0.01) and correlated with unemployment (p < 0.042), hospitalizations (p < 0.005) and lower education level (p < 0.016). Lower PedsQL™3.0 Transplant Module and PedsQL™ 4.0 Generic Core Scale scores correlated with unemployment (p = 0.006, p = 0.009) and hospitalizations (p = 0.006, p = 0.02). Pediatric transplant recipients who survive to adulthood have lower physical HRQOL, measurable transplant-related disability and lower health utility. Transplantation is life saving; however, physical and psychological sequelae continue to affect health status up to two decades later.

Alveolar ridge augmentation using distraction osteogenesis: a clinical trial

BACKGROUND

Severely resorbed ridges present a great challenge to prosthodontic rehabilitation. Available reconstructive options include autologous/alloplastic augmentation with questionable results, or regeneration of new bone under gradual and controlled tension using distraction osteogenesis. This study focused on use of distraction osteogenesis for the treatment of vertically deficient alveolar ridges to assess its feasibility and outcome.

MATERIALS AND METHODS

Alveolar distraction osteogenesis (ADO) was studied at 10 different intra-oral, partial or complete edentulous sites. After a latency period of 5 days, distraction was carried out for 6-7 days at the rate of 0.5 mm every 12 hours (1 mm/day). Distractor was removed after a consolidation period of 12 weeks.

RESULTS

The mean height gained at the 10 intra-oral sites was 4.8 mm with standard deviation of ± 0.056. The mean follow-up period was 2 years. Complications of therapy included hardware failure, wound gape and extra-oral scar. The overall complication rate was 10%.

CONCLUSION

Distraction osteogenesis is a promising option to aid uneventful prosthodontic rehabilitation of severe vertically resorbed alveolar ridges.

Microbial and pathological findings in farmed Atlantic salmon Salmo salar with proliferative gill inflammation

Proliferative gill inflammation (PGI) is an important cause of loss in seawater-farmed Atlantic salmon in Norway. Several microbes have been associated with PGI, including the commonly but not exclusively observed inclusions (epitheliocysts) within the gill lamellae related to infection with 'Candidatus Piscichlamydia salmonis'. Atlantic salmon transferred in the spring of 2004 to 12 seawater farms situated in mid- and southwest Norway were sampled throughout that year. Outbreaks of PGI, as evaluated by clinical examination, histology, and mortality data, were diagnosed in 6 of 7 farms in southwest Norway but not in the 5 farms studied in mid-Norway. Generally, mortality started 3 to 5 mo after seawater transfer and outbreaks lasted at least 1 to 3 mo. 'Ca. P. salmonis' was detected by real-time PCR only in fish from PGI-affected farms and our results indicate an association between 'Ca. P. salmonis' load and PGI severity. Likewise, although widely distributed in all 12 farms studied, epitheliocyst prevalence and number per fish as observed by histology appears associated with PGI prevalence and severity. However, the occurrence of epitheliocysts showed no association with molecular detection of 'Ca. P. salmonis', suggesting that at least 1 other organism is responsible for many of the observed inclusions. A microsporidian, Desmozoon lepeophtherii, was identified at high prevalence regardless of fish and farm PGI status, but at higher loads in fish with PGI. Our results support a multifactorial etiology for PGI in which 'Ca. P. salmonis', an unidentified epitheliocyst agent, and the microsporidian are contributing causes. No evidence for the involvement of Atlantic salmon paramyxovirus in PGI development was identified in the present study. High water temperatures and ectoparasites probably exacerbated mortality.

International study of asthma and allergies in childhood: phase 3 in the Syrian Arab Republic

The International Study of Asthma and Allergies in Childhood (ISAAC) uses standardized symptom-based questionnaires to describe the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema in children worldwide. Three governorates in the Syrian Arab Republic (Aleppo, Lattakia and Tartous) participated in ISAAC phase 3 in 2001-03. Adolescents in the 13-14 year age group and parents of the 6-7-year-old children completed the questionnaire about asthma symptoms. The prevalence of current symptoms of asthma (wheezing in the last 12 months) in different centres ranged from 4.7% to 5.7% for 6-7-year-olds and 3.9% to 6.5% for 13-14-year-olds. In 13-14-year-olds the prevalence of severe speech-limiting wheeze was 2.0%-3.5%, of rhinoconjunctivitis was 8.6%-14.6% and of eczema was 3.3%-4.2%.

Friedreich's ataxia cardiomyopathy: case based discussion and management issues

Cardiac involvement is common in Friedreich's Ataxia and is a common cause of premature death. Evidence regarding treatment of congestive heart failure in patients with Friedreich's Ataxia is lacking. The case of a 31-year-old male with advanced Friedreich's Ataxia who presented with an acute diarrhoeal illness and features of acute heart failure is discussed. We then review the reported cardiac manifestations of Friedreich's Ataxia and discuss management options.

Use of collagen in extraoral wounds

The basic fundamental elements that collagen bring into the wound activity are its hemostatic effect, its interaction with platelets and interaction with fibronection, increase in fluid exudates, increase in cellular components (macrophages) and support for fibroblastic proliferation into wound activity. In this way collagen plays a significant parts in almost every function of the body. Previously broad use of collagen was stifled because of cost, recent advances made it possible to develop cost effective collagen. In this study twenty patients of maxillofacial wounds were treated with the use of collagen. The results were satisfactory without any significant complication.

Non-contact left ventricular endocardial mapping in cardiac resynchronisation therapy

BACKGROUND

Up to 30% of patients with heart failure do not respond to cardiac resynchronisation therapy (CRT). This may reflect placement of the coronary sinus lead in regions of slow conduction despite optimal positioning on current criteria.

OBJECTIVES

To characterise the effect of CRT on left ventricular activation using non-contact mapping and to examine the electrophysiological factors influencing optimal left ventricular lead placement.

METHODS

and results: 10 patients implanted with biventricular pacemakers were studied. In six, the coronary sinus lead was found to be positioned in a region of slow conduction with an average conduction velocity of 0.4 m/s, v 1.8 m/s in normal regions (p < 0.02). Biventricular pacing with the left ventricle paced 32 ms before the right induced the optimal mean velocity time integral and timing for fusion of depolarisation wavefronts from the right and left ventricular pacing sites. Pacing outside regions of slow conduction decreased left ventricular activation time and increased cardiac output and dP/dt(max) significantly.

CONCLUSIONS

In patients undergoing CRT for heart failure, non-contact mapping can identify regions of slow conduction. Significant haemodynamic improvements can occur when the site of left ventricular pacing is outside these slow conduction areas. Failure of CRT to produce clinical benefits may reflect left ventricular lead placement in regions of slow conduction which can be overcome by pacing in more normally activating regions.

Oxidative stress is the master operator of drug and chemically-induced programmed and unprogrammed cell death: Implications of natural antioxidants in vivo

ROS, RNS, BRIs and ROS-RNS hybrids are produced during drug or chemical metabolism in vivo. These reactive species are instrumental to the culmination of cellular oxidative stress (OS). OS, once turned on, does not spare any vital intracellular macromolecule, such as glutathione, DNA, RNA, proteins, enzymes, lipids and ATP. Since concentration gradients of such components are very delicately balanced for normal cellular functioning, a gross perturbation leads to cell injury and cell death. Abundant evidence now suggests that intracellular antioxidants keep OS in check and maintain homeostasis. Our laboratory has focused on the role of OS in orchestrating various forms of cell death during drug and chemically-induced target organ toxicity and their counteraction by various natural or synthetic antioxidants in in vivo models. Despite complexity of the in vivo models, results show that metabolism of xenobiotics are invariably associated with different degrees of OS and natural antioxidants such as grape seed extract, bitter melon extract (Momordica charantia) and N-acetylcysteine (NAC) which were very effective in counteracting organ toxicities by minimizing events linked to OS (lipid peroxidation and total glutathione), and CAD-mediated DNA fragmentation. Phytoextract exposure rescued cells from toxic assaults, protected genomic integrity, and minimized apoptotic, necrotic and apocrotic (oncotic necrosis) cell deaths. Pre-exposure mode was more effective than post-exposure route. Overall scenario suggests that OS may have been the prime modulator of death and/or survival programs, whereas, antioxidants may have imparted a dual role in either erasing death signals or reviving survival signals, and a combination of antioxidants may be more beneficial than a single entity to influence a number of intracellular events operating simultaneously to neutralize chaotic toxicological consequences.

Contribution of ionotropic glutamate receptors and voltage-dependent calcium channels to the potentiation phenomenon induced by transient pentylenetetrazol in the CA1 region of rat hippocampal slices

The role of ionotropic glutamate receptors and voltage-dependent calcium channels (VDCCs) in potentiation phenomenon and epileptic activity induced by a transient pentylenetetrazol (PTZ) application in the CA1 region of rat hippocampal slices was investigated. Also we examined whether adenosine as an inhibitory neuromodulator would interact with expression of the long-lasting effect of transient PTZ. Population spikes (PS) were recorded in the CA1 cell body layer of the hippocampal slices following stratum radiatum stimulation. Changes in the PS amplitude potentiation and number of extra PS, which induced by transient PTZ were used as indices to quantify the effects of drugs. PS input-output curve was significantly increased 10 min after PTZ application and persisted at least for 60 min after PTZ washout. Polyspikes also appeared, but did not persist. Both ketamine and APV reduced the extent of potentiation of PS amplitude but had no effect on number of extra PS. The selective non-NMDA receptor antagonist CNQX prevented the amplitude potentiation and the generation of extra PS. The blocker of VDCCs, verapamil, prevented the amplitude potentiation and inhibited polyspike activity. Co-application of adenosine and PTZ produced a rapid and reversible decrease in the PS amplitude, but PTZ-induced potentiation phenomenon was observed after washout. It is concluded that ionotropic glutamate receptors as well as VDCCs involve in the PTZ-induced LTP of PS amplitude. PTZ-induced LTP is also insensitive to adenosine. The epileptiform activity induced by a transient PTZ application could be attributed to VDCCs. The polyspikes mediated by VDCCs are dependent on prior activation of AMPA receptors.