Utilisation of specialist epilepsy services and antiseizure medication adherence rates in a cohort of people with epilepsy (PWE) accessing emergency care

BACKGROUND

An epilepsy-related attendance at A&E is associated an increased risk of subsequent death within 6 months. Although further work is required to provide a definitive explanation to account for these findings, in the interim it would seem reasonable that services are designed to ensure timely access and provide support at a time of greatest risk. We aim to determine the frequency of patients accessing specialist neurology services following an epilepsy-related admission/unscheduled care episode and consider ASM adherence at the point of attendance.

METHODS

Patients were identified retrospectively via the NHS Greater Glasgow and Clyde live integrated epilepsy Dashboard following an unscheduled epilepsy-related admission or A&E attendance between 1st January 2022 and 30th June 2022. We calculated adherence to anti-seizure medication for a period of 6 months prior to admission and defined poor medication adherence as a medication possession ratio of less than 80 %. We evaluated the rate of any outpatient neurology clinic attendance in the subsequent 3, 6 and 12 months following an epilepsy-related unscheduled care episode. Additional clinical information was identified via the electronic patient records.

RESULTS

Between 1st Jan 2022 and 30th June 2022, there were 266 emergency care seizure-related attendances. The mean age at attendance was 46 years (range: 16-91). Most of PWE were males (63 %) and 37 % were females. Epilepsy classification-29.3 % had GGE, 41.7% had focal epilepsy, and in 29 % of cases the epilepsy was unclassified. Of the admissions, 107/ 266 (40.2 %) generated follow-up within 6 months of attendance. Poor medication adherence was noted in 54/266 (20.3 %). 28.2 % of cases had input from on-call neurology service during admission/ED attendance, and of those 60 % had ASM adjusted. 18 % of attendances had a background diagnosis of learning disability. One-third of attendances of PWE had a history of mental health disorder 35 % (93/266). 25 % of ED attendances noted an active history of alcohol consumption misuse or/and recreational drug use. 14 (5.5 %) of PWE died during the period of interest (12 months following the last ED visit). In 6/14 (42.3 %) death was associated with poor medication adherence.

CONCLUSION

This study demonstrates that a significant proportion of patients who experienced seizure-related admissions/ attendance did not access specialist neurology services in a timely manner. In addition, poor medication adherence remains a problem for a substantial number of people living with epilepsy. Early access to specialist services may go some way to improving care and reducing excessive mortality in PWE by allowing anti-seizure medication to be titrated and poor medication adherence to be addressed in those at greatest risk.

Beyond antibiotics: phage-encoded lysins against Gram-negative pathogens

Antibiotics remain the frontline agents for treating deadly bacterial pathogens. However, the indiscriminate use of these valuable agents has led to an alarming rise in AMR. The antibiotic pipeline is insufficient to tackle the AMR threat, especially with respect to the WHO critical category of priority Gram-negative pathogens, which have become a serious problem as nosocomial and community infections and pose a threat globally. The AMR pandemic requires solutions that provide novel antibacterial agents that are not only effective but against which bacteria are less likely to gain resistance. In this regard, natural or engineered phage-encoded lysins (enzybiotics) armed with numerous features represent an attractive alternative to the currently available antibiotics. Several lysins have exhibited promising efficacy and safety against Gram-positive pathogens, with some in late stages of clinical development and some commercially available. However, in the case of Gram-negative bacteria, the outer membrane acts as a formidable barrier; hence, lysins are often used in combination with OMPs or engineered to overcome the outer membrane barrier. In this review, we have briefly explained AMR and the initiatives taken by different organizations globally to tackle the AMR threat at different levels. We bring forth the promising potential and challenges of lysins, focusing on the WHO critical category of priority Gram-negative bacteria and lysins under investigation for these pathogens, along with the challenges associated with developing them as therapeutics within the existing regulatory framework.

Capacity Building for Vaccine Manufacturing Across Developing Countries: The Way Forward

Approved vaccines prevent 2 to 3 million deaths per year. There is a lack of equitable access to vaccines in the low- and middle-income developing nations. Challenges in the life cycle of vaccine production include process development, lead time, intellectual property, and local vaccine production. A robust and stable manufacturing process and constant raw material supplies over decades is critical. In a continuously evolving vaccine landscape, the need of the hour for developing nations is to manufacture their own vaccines besides having supply security, control over production scheduling and sustainability, control of costs, socio-economic development, and rapid response to local epidemics. There is a need for capacity building of workforce development, technology transfer, and financial support. Technology transfer has improved vaccine access and reduced prices of vaccines. Capacity building for the manufacturing of vaccines in developing countries has always been an area of paramount importance and more so in a pandemic situation.

Rapa Nui (Easter Island) Rano Raraku crater lake basin: Geochemical characterization and implications for the Ahu-Moai Period

Rano Raraku, the crater lake constrained by basaltic tuff that served as the primary quarry used to construct the moai statues on Rapa Nui (Easter Island), has experienced fluctuations in lake level over the past centuries. As one of the only freshwater sources on the island, understanding the present and past geochemical characteristics of the lake water is critical to understand if the lake could have been a viable freshwater source for Rapa Nui. At the time of sampling in September 2017, the maximum lake depth was ~1 m. The lake level has substantially declined in the subsequent years, with the lake drying almost completely in January 2018. The lake is currently characterized by highly anoxic conditions, with a predominance of ammonium ions on nitrates, a high concentration of organic carbon in the water-sediment interface and reducing conditions of the lake, as evidenced by Mn/Fe and Cr/V ratios. Our estimates of past salinity inferred from the chloride mass balance indicates that it was unlikely that Rano Raraku provided a viable freshwater source for early Rapa Nui people. The installation of an outlet pipe around 1950 that was active until the late 1970s, as well as grazing of horses on the lake margins appear to have significantly impacted the geochemical conditions of Rano Raraku sediments and lake water in recent decades. Such impacts are distinct from natural environmental changes and highlight the need to consider the sensitivity of the lake geochemistry to human activities.

Blood-brain barrier amenable gold nanoparticles biofabrication in aged cell culture medium

Green fabrication of nanoscale materials is highly desirable because of associated adverse effects with conventional nanomaterial biomedical applications. Moreover, the higher selective nature of the blood-brain barrier (BBB) limits the brain ailments treatment through conventional chemotherapy, thus providing room for nanotechnology-based modalities for BBB traversing. In this contribution, we have biosynthesized gold nanoparticles from the HAuCl4 solution in the aged cells culture medium. This approach is highly facile without any other chemical utilization. The cell culture medium age and cell number can tune the Au nanoparticles (AuNPs) size from 2 to several hundred nm. The 24 h MTT assay and cell uptake studies in vitro and murine models' vital organs (liver, kidney, spleen, lung, and heart) study up to 48 h demonstrated that biosynthesized AuNPs were biocompatible and BBB amenable. Interestingly, the transferrin and cell culture medium isolated proteins were found factors responsible for HAuCl4 solution biomineralization and size control. Moreover, the protein corona on biosynthesized AuNPs could help them traverse BBB both in vitro and in vivo, suggesting their potential applications for brain disease theranostics. In conclusion, the biosynthesis of AuNPs from aged cells medium is highly facile, green, and biocompatible for brain disease theranostics.

Managing People with Diabetes Fasting for Ramadan During the COVID-19 Pandemic: A South Asian Health Foundation Update

The month of Ramadan forms one of the five pillars of the Muslim faith. Adult Muslims are obligated to keep daily fasts from dawn to sunset, with exceptions. This year Ramadan is due to begin on 23 April 2020 and the longest fast in the UK will be approximately 18 hours in length. In addition, due to the often high-calorie meals eaten to break the fast, Ramadan should be seen as a cycle of fasting and feasting. Ramadan fasting can impact those with diabetes, increasing the risk of hypoglycaemia, hyperglycaemia and dehydration. This year, Ramadan will occur during the global COVID-19 pandemic. Reports show that diabetes appears to be a risk factor for more severe disease with COVID-19. In addition, the UK experience has shown diabetes and COVID-19 is associated with dehydration, starvation ketosis, diabetic ketoacidosis and hyperosmolar hyperglycaemic state. This makes fasting in Ramadan particularly challenging for those Muslims with diabetes. Here, we discuss the implications of fasting in Ramadan during the COVID-19 pandemic and make recommendations for those with diabetes who wish to fast.

Inhibition ELISA as a putative tool for the identification and quantification of meningococcal A and X polysaccharides at various stages of vaccine development

The multivalent glycoconjugate vaccines against Neisseria meningitidis are extremely high-priced for the developing world. The high cost is due to the manufacturing set-up required to produce an effective vaccine and other inflators like complex production steps including the production and purification of the polysaccharide and consequently its conjugation with a protein and finally formulating the finished multivalent product. There is an urgent need for assays which are simple, precise, can be applicable at multiple steps and contribute in reducing the overall manufacturing cost, thereby making the vaccines more equitable to the developing world. WHO recommends serological tests for polysaccharide identification and quantitation at different stages of conjugate vaccine production. We report development of inhibition ELISAs for the identification and quantification of N. meningitidis serogroup A (MenA) and N. meningitidis serogroup X (MenX) polysaccharides (PSs) in samples from stage of cell banking till production of finished product. The method was qualified on various parameters such as specificity, intermediate precision, sensitivity and accuracy. Our results provide a proof of concept for the use of an inhibition ELISA as a common tool for the identification and quantification of PS at various stages of vaccine development and manufacture.

The efficacy and safety of probiotics for prevention of chemoradiotherapy-induced diarrhea in people with abdominal and pelvic cancer: a systematic review and meta-analysis

A systematic review and meta-analysis were designed to evaluate the efficacy and safety of probiotics for prevention of chemoradiotherapy-induced diarrhea in people with abdominal and pelvic cancer. We searched the Cochrane Library, PubMed, EMBASE and Web of Science up to November 2015. We also hand searched the citation lists of included studies and previously identified systematic reviews to identify further relevant trials. Odds ratio (OR) was used to compare efficacy, and the pooled OR was estimated using a random effects model; heterogeneity was assessed with Cochran's Q and the Higgins' I²-test. Two reviewers assessed trial quality and extracted data independently. Analysis and bias for each included study were performed using Review Manager 5.2. Nine randomized and placebo-controlled studies (N=1265 participants) were included for assessing efficacy, of which seven were about radiotherapy and two about chemotherapy. Probiotic groups were compared with control groups with respect to the the incidence of diarrhea, OR=0.47 (95% confidence interval 0.28-0.76; P=0.002). Eleven studies, including 1612 people (873 consuming probiotics and 739 not consuming probiotics), were used for the analysis of safety of probiotics. Of the 11 studies, seven studies had no adverse events (AEs) caused by probiotics, whereas four studies reported varying degrees of AEs in their treatment. Probiotics may have a beneficial effect in prevention of chemoradiotherapy-induced diarrhea generally, especially for Grade⩾2 diarrhea. Probiotics may rarely cause AEs.

Rapid processes for purification of capsular polysaccharides from Neisseria meningitidis serogroups A and C

The glycoconjugate vaccines against Neisseria meningitidis are highly effective, however most of these vaccines are expensive and still out of reach in the developing world as well as the technical know-how and the set-up required for the consistent production of pure polysaccharide is limited. Our laboratory has developed rapid, efficient and scalable processes for the downstream purification of N. meningitidis serogroup A (MenA) and serogroup C (MenC) capsular polysaccharides (PS). The MenC-PS was purified with a novel 2-step procedure including de-O-acetylation and hydrophobic interaction chromatography whereas, MenA-PS was purified using a rapid method as compared to the prior art. The purified PSs were analyzed by various analytical tests including nuclear magnetic resonance, molecular weight, composition and purity analyses to meet desired specifications. Our results provide a proof of principle for the purification of MenA-PS and MenC-PS with reduced timelines.

Development and characterization of Haemophilus influenzae type b conjugate vaccine prepared using different polysaccharide chain lengths

Capsular polysaccharide conjugates of Haemophilus influenzae type b (Hib) are important components of several mono- or multi-valent childhood vaccines. However, their access to the most needy people is limited due to their high cost. As a step towards developing a cost effective and more immunogenic Hib conjugate vaccine, we present a method for the preparation of Hib capsular polysaccharide (PRP)-tetanus toxoid (TT) conjugates using optimized PRP chain length and conjugation conditions. Reactive aldehyde groups were introduced into the polysaccharides by controlled periodate oxidation of the native polysaccharide, which were subsequently covalently linked to hydrazide derivatized tetanus toxoid by means of reductive amination. Native polysaccharides were reduced to average 100 or 50kDa polysaccharide and 10kDa oligosaccharides in a controlled manner. Various conjugates were prepared using Hib polysaccharide and oligosaccharide yielding conjugates with polysaccharide to protein ratios in the range of 0.25-0.5 (w/w) and free saccharide levels of less than 10%. Immunization of Sprague Dawley rats with the conjugates elicited specific antibodies to PRP. The low molecular weight PRP-TT conjugates were found to be more immunogenic as compared to their high molecular weight counterparts and the PRP-TT reference vaccine.

Pattern of facial palsy in a typical Nigerian specialist hospital

BACKGROUND

Data on incidence of facial palsy is generally lacking in Nigeria.

OBJECTIVE

To assess six years' incidence of facial palsy in Murtala Muhammed Specialist Hospital (MMSH), Kano, Nigeria.

METHOD

The records of patients diagnosed as facial problems between January 2000 and December 2005 were scrutinized. Data on diagnosis, age, sex, side affected, occupation and causes were obtained.

RESULTS

A total number of 698 patients with facial problems were recorded. Five hundred and ninety four (85%) were diagnosed as facial palsy. Out of the diagnosed facial palsy, males (56.2%) had a higher incidence than females; 20-34 years age group (40.3%) had a greater prevalence; the commonest cause of facial palsy was found out to be Idiopathic (39.1%) and was most common among business men (31.6%). Right sided facial palsy (52.2%) was predominant. Incidence of facial palsy was highest in 2003 (25.3%) and decreased from 2004.

CONCLUSION

It was concluded that the incidence of facial palsy was high and Bell's palsy remains the most common causes of facial (nerve) paralysis.

Resveratrol-induced apoptosis is enhanced in low pH environments associated with cancer

Many critical factors such as hypoxia, nutrient deficiency, activation of glycolytic pathway/Warburg effect contribute to the observed low pH in tumors compared to normal tissue. Studies suggest that such tumor specific acidic environment can be exploited for the development of therapeutic strategies against cancer. Independent observations show reduction in pH of mammalian cells undergoing internucleosomal DNA fragmentation and apoptosis. As such, our group has extensively demonstrated that anticancer mechanisms of different plant polyphenols involve mobilization of endogenous copper and consequent internucleosomal DNA breakage. Copper is redox active metal, an essential component of chromatin and is sensitive to subtle pH changes in its microenvironment. Here we explored whether, acidic pH promotes growth inhibition, apoptosis, and DNA damaging capacity of chemopreventive agent resveratrol. Our results reveal that growth inhibition and internucleosomal DNA fragmentation induced apoptosis in Capan-2 and Panc-28 pancreatic cancer cell lines (and not in normal HPDE cells) by resveratrol is enhanced at lower pH. Using comet assay, we further demonstrate that DNA breakage by resveratrol is enhanced with acidification. Membrane permeable copper specific chelator neocuproine (and not iron chelator orthophenanthroline) abrogated growth inhibition and apoptosis by resveratrol. Western blot results show enhanced activation of DNA laddering marker H2.aX by resveratrol at acidic pH that was reversed by neocuproine and not by orthophenanthroline. Our findings provide irrevocable proof that low pH environment can be turned into tumor weakness and assist in eradication of cancer cells by resveratrol.

Age related outcome in acute subdural haematoma following traumatic head injury

Acute subdural haematoma (ASDH) is one of the conditions most strongly associated with severe brain injury. Reports prior to 1980 describe overall mortality rates for acute subdural haematomas (SDH's) ranging from 40% to 90% with poor outcomes observed in all age groups. Recently, improved results have been reported with rapid diagnosis and surgical treatment. The elderly are predisposed to bleeding due to normal cerebral atrophy related to aging, stretching the bridging veins from the dura. Prognosis in ASDH is associated with age, time from injury to treatment, presence of pupillary abnormalities, Glasgow Coma Score (GCS) or motor score on admission, immediate coma or lucid interval, computerized tomography findings (haematoma volume, degree of midline shift, associated intradural lesion, compression of basal cisterns), post-operative intracranial pressure and type of surgery. Advancing age is known to be a determinant of outcome in head injury. We present the results of a retrospective study carried out in Beaumont Hospital, Dublin, Ireland's national neurosurgical centre. The aim of our study was to examine the impact of age on outcome in patients with ASDH following severe head injury. Only cases with acute subdural haematoma requiring surgical evacuation were recruited. Mortality was significantly higher in older patients (50% above 70 years, 25.6% between 40 and 70 years and 26% below 40 years). Overall poor outcome (defined as Glasgow outcome scores 3-5) was also higher in older patients; 74.1% above 70 years, 48% between 40 and 70 years and 30% below 40 years. Poor outcome in traumatic acute subdural haematoma is higher in elderly patients even after surgical intervention.

Plumbagin induces cell death through a copper-redox cycle mechanism in human cancer cells

Plumbagin, a naphthoquinone derived from the medicinal plant Plumbago zeylanica has been shown to exert anticancer and anti-proliferative activities in cells in culture as well as animal tumor models. In our previous paper, we have reported the cytotoxic action of plumbagin in plasmid pBR322 DNA as well as human peripheral blood lymphocytes through a redox mechanism involving copper. Copper has been shown to be capable of mediating the action of several plant-derived compounds through production of reactive oxygen species (ROS). The objective of the present study was to determine whether plumbagin induces apoptosis in human cancer cells through the same mechanism which we proposed earlier. Using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay, 3-(4,5-B-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay for cell growth inhibition, histone/DNA ELISA, homogeneous caspase-3/7 assay for apoptosis as well as alkaline comet assay for DNA single-strand breaks detection in this report, we confirm that plumbagin causes effective cell growth inhibition, induces apoptosis and generates single-strand breaks in cancer cells. Incubation of cancer cells with scavengers of ROS and neocuproine inhibited the cytotoxic action of plumbagin proving that generation of ROS and Cu(I) are the critical mediators in plumbagin-induced cell growth inhibition. This study is the first to investigate the copper-mediated anticancer mechanism of plumbagin in human cancer cells and these properties of plumbagin could be further explored for the development of anticancer agents with higher therapeutic indices, especially for skin cancer.

Pattern of ptosis in Kano North-West Nigeria

OBJECTIVE

Epidemiological data on ptosis are generally lacking in the developing nations. The aim of this study was to assess the seven years pattern of ptosis in a Nigerian Specialist Hospital, Kano North-West Nigeria.

METHOD

The records of patients' diagnosis as ptosis between 2000 and 2006 were scrutinized. Data such as age, sex, cause, socioeconomic status, side of ptosis and management were obtained.

RESULT

A total number of 104 patients were recorded. High prevalence was found as follows: male 102(65.4%); right side (61.5%); trauma (RTA) (60.9%); civil servants (38.5.8%) and age group: 51-60 years (25.6%).

CONCLUSION

It was concluded that trauma from road traffic accident (RTA) is the major aetiological factor and the right side mostly affected.

RECOMMENDATION

It is recommended that surgical training and facilities for ptosis correction is off priority.

Paralytic poliomyelitis during the pre-, peri- and post-suspension periods of a polio immunization campaign

A total of 744 paralytic poliomyelitis patients (0-59 months old) were reviewed and results showed a critical and perpetual surge during 2003 (20.2%), 2004 (27.4%) and 2005 (41%). A slight male predominance (56%) was reported and a high incidence was reported in the low socioeconomic (68.3%) and urban setting (60.3%) groups. It was concluded that the polio eradication campaigning programmes in Nigeria had not been successful and that legislation on poliomyelitis was required.

Oxidative breakage of cellular DNA by plant polyphenols: a putative mechanism for anticancer properties

Plant polyphenols are important components of human diet and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring antioxidants but also act as prooxidants catalyzing DNA degradation in the presence of transition metal ions such as copper. We have shown that several of these compounds are able to bind both DNA and Cu(II) forming a ternary complex. A redox reaction of the polyphenols and Cu(II) in the ternary complex may occur leading to the reduction of Cu(II) to Cu(I), whose reoxidation generates a variety of reactive oxygen species (ROS). We have further confirmed that the polyphenol-Cu(II) system is indeed capable of causing DNA degradation in cells such as lymphocytes. We have also shown that polyphenols alone (in the absence of added copper) are also capable of causing DNA breakage in cells. Neocuproine (a Cu(I) sequestering agent) inhibits such DNA degradation. It also inhibits the oxidative stress generated in lymphocytes indicating that the cellular DNA breakage involves the generation of Cu(I) and formation of ROS. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and polyphenols to generate ROS. Thus, our results are in support of our hypothesis that anticancer mechanism of plant polyphenols involves mobilization of endogenous copper possibly chromatin bound copper and the consequent prooxidant action.

Ascorbic acid mobilizes endogenous copper in human peripheral lymphocytes leading to oxidative DNA breakage: a putative mechanism for anticancer properties

Several decades back ascorbic acid was proposed as an effective anticancer agent. However, this idea remained controversial and the mechanism of action unclear. In this paper, we show that ascorbic acid at a concentration reported to be achievable through high doses of oral consumption is capable of cytotoxic action against normal cells. Several antioxidants of both animal as well as plant origin including ascorbic acid also possess prooxidant properties. Copper is an essential component of chromatin and can take part in redox reactions. Previously we have proposed a mechanism for the cytotoxic action of plant antioxidants against cancer cells that involves mobilization of endogenous copper ions and the consequent generation of reactive oxygen species. Using human peripheral lymphocytes and Comet assay we show here that ascorbic acid is able to cause oxidative DNA breakage in normal cells at a concentration of 100-200 microM. Neocuproine, a Cu(I) specific sequestering agent inhibited DNA breakage in a dose dependent manner indicating that Cu(I) is an intermediate in the DNA cleavage reaction. The results are in support of our above hypothesis that involves events that lead to a prooxidant action by antioxidants. The results would support the idea that even a plasma concentration of around 200 microM. would be sufficient to cause pharmacological tumor cell death particularly when copper levels are elevated. This would account for the observation of several decades back by Pauling and co-workers where oral doses of ascorbic acid in gram quantities were found to be effective in treating some cancers.

Plant polyphenols mobilize endogenous copper in human peripheral lymphocytes leading to oxidative DNA breakage: A putative mechanism for anticancer properties

Plant polyphenols are important components of human diet and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring antioxidants but also act as prooxidants catalyzing DNA degradation in the presence of transition metal ions such as copper. Using human peripheral lymphocytes and Comet assay we have previously confirmed that resveratrol-Cu(II) is indeed capable of causing DNA degradation in cells. In this paper we show that the polyphenols alone (in the absence of added copper) are also capable of causing DNA breakage in cells. Incubation of lymphocytes with neocuproine inhibited the DNA degradation confirming that Cu(I) is an intermediate in the DNA cleavage reaction. Further, we have also shown that polyphenols generate oxidative stress in lymphocytes which is inhibited by scavengers of reactive oxygen species and neocuproine. These results are in further support of our hypothesis that anticancer mechanism of plant polyphenols involves mobilization of endogenous copper, possibly chromatin bound copper, and the consequent prooxidant action.

Prevalence of depression in patients with coronary artery disease in a tertiary care hospital in Pakistan

OBJECTIVE

To determine the prevalence of depression in patients with coronary artery disease (CAD) in a tertiary care hospital setting in Pakistan.

METHODS

One hundred and fifty four patients of CAD (115 males and 39 females) were randomly selected from the outpatient department and wards of the National Institute of Cardiovascular Diseases, Karachi and were scored for depression via the Hospital Anxiety and Depression Scale. Basic demographic data and disease variables were also collected.

RESULTS

The point prevalence of depression in the sample was 37% (31.3% males and 53.8% females). Female sex, income level below Rs. 5000 per month, low education level, outpatient, single earning family member and hypertension were few variables associated positively with depression (p < 0.05). Only one patient was receiving treatment for depression by his cardiologist.

CONCLUSION

Depression is prevalent in CAD patients in Pakistan. Economic conditions may pose an additional threat on these patients. Treating physicians (especially cardiologists) need to be aware of this co-morbidity so as to be able to diagnose and adequately manage such patients.

Molecular mechanisms involved in human platelet aggregation by synergistic interaction of platelet-activating factor and 5-hydroxytryptamine

Our recent studies have shown that co-activation of Gq and Gi proteins by 5-hydroxytryptamine (5-HT) and adrenaline show synergism in human platelet aggregation. This study was conducted to examine the mechanism(s) of synergistic interaction of 5-HT and platelet activating factor (PAF) in human platelets. We show that PAF, but not 5-HT, increased platelet aggregation in a concentration-dependent manner. However, low concentrations of 5-HT (2 microM) potentiated platelet aggregation induced by subthreshold concentration of PAF (40 nM) indicating a synergistic interaction between the two agonists and this synergism was blocked by receptor antagonists to either 5-HT or PAF. 5-HT also potentiated the effect of PAF on thromboxane A2 (TXA2) formation and phosphorylation of extracellularly regulated mitogen-activated protein kinases (ERK1/2). The synergism of 5-HT and PAF in platelet aggregation was inhibited by calcium (Ca2+) channel blockers, verapamil and diltiazem, phospholipase C (PLC) inhibitor, U73122, cyclooxygenase (COX) inhibitor, indomethacin, and MEK inhibitor, PD98059. These data suggest that synergistic effect of 5-HT and PAF on human platelet aggregation involves activation of PLC/Ca2+, COX and MAP kinase pathways.

Leptin receptor long-form signalling in a human liver cell line

Expression of the long form of the leptin receptor was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting in the human liver cell line WRL68. Leptin (50-200 nM) significantly increased tyrosine phosphorylation of STAT cytoplasmic transcription factors STAT3 and STAT5b in a dose-dependent manner and produced a gel-shift with STAT3- and STAT5-specific oligonucleotides. WRL68 cells therefore provide the first human in vitro hepatocyte system in which to study leptin receptor-mediated signalling and to elucidate the role of leptin in liver.

Fatty acids inhibit leptin signalling in BRIN-BD11 insulinoma cells

The effect of treatment with a 0.03% fatty acid (FA) cocktail on leptin-receptor-mediated STAT (signal transducers and activators of transcription) activation in the rat insulinoma cell line BRIN-BD11 was investigated. Leptin (10 nM) stimulated the tyrosine phosphorylation of STAT3 and STAT5b. Acute treatment with FAs prevented leptin-stimulated STAT3 tyrosine phosphorylation and significantly raised basal STAT5 phosphorylation. A chronic treatment (5 days) of BRIN-BD11 cells with FAs similarly attenuated leptin-stimulated STAT tyrosine phosphorylation. Chronic FA treatment also attenuated prolactin-stimulated STAT5b tyrosine phosphorylation but not interleukin-6-stimulated STAT3 tyrosine phosphorylation, suggesting that the effect is receptor/ligand specific. TaqMan analysis of gene expression following chronic FA treatment showed neither a decrease in the amount of leptin receptor (Ob-R) mRNA, nor an increase in the negative regulators of STAT signalling, SOCS3 (suppressors of cytokine signalling) or cytokine inducible sequence (CIS). These data demonstrate that FAs modulate leptin and prolactin signalling in beta-cells, implying that high levels of circulating FAs present in obese individuals affect the action of selective cytokines in beta-cell function.

Incidence of insulin dependent diabetes mellitus in Karachi, Pakistan

OBJECTIVES

To determine the incidence of insulin dependent diabetes mellitus (IDDM) among children aged up to 16 years residing in the city of Karachi, Pakistan, during the five years from 1989 to 1993.

DESIGN

Retrospective study of incidence using hospital and clinic records.

SETTING

The city of Karachi, Pakistan.

SUBJECTS

Children satisfying standard criteria for the diagnosis of IDDM, attending treatment facilities for the first time during the study period.

MAIN OUTCOME MEASURES

The incidence of IDDM in this population and its variation by age and sex.

RESULTS

The incidence of IDDM in this population is 1.02/100000 per year, which is one of the lowest incidence rates yet reported.

CONCLUSIONS

The very low incidence of IDDM, contrasted with the substantially higher incidence among migrants, supports the view that environmental factors are the major determinants of variations in the incidence of this condition between populations.