Erratum: Role of adipocyte Na,K-ATPase oxidant amplification loop in cognitive decline and neurodegeneration

[This corrects the article DOI: 10.1016/j.isci.2021.103262.].

Insight into the Inter-Organ Crosstalk and Prognostic Role of Liver-Derived MicroRNAs in Metabolic Disease Progression

Dysfunctional hepatic metabolism has been linked to numerous diseases, including non-alcoholic fatty liver disease, the most common chronic liver disorder worldwide, which can progress to hepatic fibrosis, and is closely associated with insulin resistance and cardiovascular diseases. In addition, the liver secretes a wide array of metabolites, biomolecules, and microRNAs (miRNAs) and many of these secreted factors exert significant effects on metabolic processes both in the liver and in peripheral tissues. In this review, we summarize the involvement of liver-derived miRNAs in biological processes with an emphasis on delineating the communication between the liver and other tissues associated with metabolic disease progression. Furthermore, the review identifies the primary molecular targets by which miRNAs act. These consolidated findings from numerous studies provide insight into the underlying mechanism of various metabolic disease progression and suggest the possibility of using circulatory miRNAs as prognostic predictors and therapeutic targets for improving clinical intervention strategies.

Contribution of adipocyte Na/K-ATPase α1/CD36 signaling induced exosome secretion in response to oxidized LDL

Introduction

Adipose tissue constantly secretes adipokines and extracellular vesicles including exosomes to crosstalk with distinct tissues and organs for whole-body homeostasis. However, dysfunctional adipose tissue under chronic inflammatory conditions such as obesity, atherosclerosis, and diabetes shows pro-inflammatory phenotypes accompanied by oxidative stress and abnormal secretion. Nevertheless, molecular mechanisms of how adipocytes are stimulated to secrete exosomes under those conditions remain poorly understood.

Methods

Mouse and human in vitro cell culture models were used for performing various cellular and molecular studies on adipocytes and macrophages. Statistical analysis was performed using Student's t-test (two-tailed, unpaired, and equal variance) for comparisons between two groups or ANOVA followed by Bonferroni's multiple comparison test for comparison among more than two groups.

Results and discussion

In this work, we report that CD36, a scavenger receptor for oxidized LDL, formed a signaling complex with another membrane signal transducer Na/K-ATPase in adipocytes. The atherogenic oxidized LDL induced a pro-inflammatory response in in vitro differentiated mouse and human adipocytes and also stimulated the cells to secrete more exosomes. This was largely blocked by either CD36 knockdown using siRNA or pNaKtide, a peptide inhibitor of Na/K-ATPase signaling. These results showed a critical role of the CD36/Na/K-ATPase signaling complex in oxidized LDL-induced adipocyte exosome secretion. Moreover, by co-incubation of adipocyte-derived exosomes with macrophages, we demonstrated that oxidized LDL-induced adipocyte-derived exosomes promoted pro-atherogenic phenotypes in macrophages, including CD36 upregulation, IL-6 secretion, metabolic switch to glycolysis, and mitochondrial ROS production. Altogether, we show here a novel mechanism through which adipocytes increase exosome secretion in response to oxidized LDL and that the secreted exosomes can crosstalk with macrophages, which may contribute to atherogenesis.

Cognitive dysfunction associated with COVID-19: Prognostic role of circulating biomarkers and microRNAs

COVID-19 is renowned as a multi-organ disease having subacute and long-term effects with a broad spectrum of clinical manifestations. The evolving scientific and clinical evidence demonstrates that the frequency of cognitive impairment after COVID-19 is high and it is crucial to explore more clinical research and implement proper diagnostic and treatment strategies. Several central nervous system complications have been reported as comorbidities of COVID-19. The changes in cognitive function associated with neurodegenerative diseases develop slowly over time and are only diagnosed at an already advanced stage of molecular pathology. Hence, understanding the common links between COVID-19 and neurodegenerative diseases will broaden our knowledge and help in strategizing prognostic and therapeutic approaches. The present review focuses on the diverse neurodegenerative changes associated with COVID-19 and will highlight the importance of major circulating biomarkers and microRNAs (miRNAs) associated with the disease progression and severity. The literature analysis showed that major proteins associated with central nervous system function, such as Glial fibrillary acidic protein, neurofilament light chain, p-tau 181, Ubiquitin C-terminal hydrolase L1, S100 calcium-binding protein B, Neuron-specific enolase and various inflammatory cytokines, were significantly altered in COVID-19 patients. Furthermore, among various miRNAs that are having pivotal roles in various neurodegenerative diseases, miR-146a, miR-155, Let-7b, miR-31, miR-16 and miR-21 have shown significant dysregulation in COVID-19 patients. Thus the review consolidates the important findings from the numerous studies to unravel the underlying mechanism of neurological sequelae in COVID-19 and the possible association of circulatory biomarkers, which may serve as prognostic predictors and therapeutic targets in future research.

Na/K-ATPase suppresses LPS-induced pro-inflammatory signaling through Lyn

Na/K-ATPase (NKA), besides its ion transporter function, is a signal transducer by regulating Src family kinases (SFK). The signaling NKA contributes to oxidized LDL-induced macrophage foam cell formation and interacts with TLR4. However, its role in lipopolysaccharides (LPS)-induced signaling and glycolytic switch in macrophages remains unclear. Using peritoneal macrophages from NKA α1 haploinsufficient mice (NKA α1+/-), we found that NKA α1 haploinsufficiency led to enhanced LPS-stimulated NF-κB pathway, ROS signaling, and pro-inflammatory cytokines. Intraperitoneal injection of LPS resulted in more severe lung inflammation and injury with lower survival rate in NKA α1+/- mice. Additionally, LPS induced a higher extent of the metabolic switch from oxidative phosphorylation to glycolysis. Mechanistically, NKA α1 interacted with TLR4 and Lyn. The presence of NKA α1 in this complex attenuated Lyn activation by LPS, which subsequently restricted the downstream ROS and NF-κB signaling. In conclusion, we demonstrated that NKA α1 suppresses LPS-induced macrophage pro-inflammatory signaling through Lyn.

Biomarker panel for early screening of trastuzumab -induced cardiotoxicity among breast cancer patients in west virginia

Cardiotoxicity is a well-known pathophysiological consequence in breast cancer patients receiving trastuzumab. Trastuzumab related cardiotoxicity typically results in an overall decline in cardiac function, primarily characterized by reduction in left ventricular ejection fraction (LVEF) and development of symptoms associated with heart failure. Current strategies for the monitoring of cardiac function, during trastuzumab therapy, includes serial echocardiography, which is cost ineffective as well as offers limited specificity, while offering limited potential in monitoring early onset of cardiotoxicity. However, biomarkers have been shown to be aberrant prior to any detectable functional or clinical deficit in cardiac function. Hence, this study aims to develop a panel of novel biomarkers and circulating miRNAs for the early screening of trastuzumab induced cardiotoxicity. Patients with clinical diagnosis of invasive ductal carcinoma were enrolled in the study, with blood specimen collected and echocardiography performed prior to trastuzumab therapy initiation at baseline, 3- and 6-months post trastuzumab therapy. Following 6-months of trastuzumab therapy, about 18% of the subjects developed cardiotoxicity, as defined by reduction in LVEF. Our results showed significant upregulation of biomarkers and circulating miRNAs, specific to cardiac injury and remodeling, at 3- and 6-months post trastuzumab therapy. These biomarkers and circulating miRNAs significantly correlated with the cardiac injury specific markers, troponin I and T. The findings in the present study demonstrates the translational applicability of the proposed biomarker panel in early preclinical diagnosis of trastuzumab induced cardiotoxicity, further allowing management of cardiac function decline and improved health outcomes for breast cancer patients.

Role of adipocyte Na,K-ATPase oxidant amplification loop in cognitive decline and neurodegeneration

Recent studies suggest that a western diet may contribute to clinical neurodegeneration and dementia. Adipocyte-specific expression of the Na,K-ATPase signaling antagonist, NaKtide, ameliorates the pathophysiological consequences of murine experimental obesity and renal failure. In this study, we found that a western diet produced systemic oxidant stress along with evidence of activation of Na,K-ATPase signaling within both murine brain and peripheral tissues. We also noted this diet caused increases in circulating inflammatory cytokines as well as behavioral, and brain biochemical changes consistent with neurodegeneration. Adipocyte specific NaKtide affected by a doxycycline on/off expression system ameliorated all of these diet effects. These data suggest that a western diet produces cognitive decline and neurodegeneration through augmented Na,K-ATPase signaling and that antagonism of this pathway in adipocytes ameliorates the pathophysiology. If this observation is confirmed in humans, the adipocyte Na,K-ATPase may serve as a clinical target in the therapy of neurodegenerative disorders.

A Review of miRNAs as Biomarkers and Effect of Dietary Modulation in Obesity Associated Cognitive Decline and Neurodegenerative Disorders

There has been a progressive increase in the prevalence of obesity and its comorbidities such as type 2 diabetes and cardiovascular diseases worldwide. Recent studies have suggested that the crosstalk between adipose tissue and central nervous system (CNS), through cellular mediators and signaling pathways, may causally link obesity with cognitive decline and give rise to neurodegenerative disorders. Several mechanisms have been proposed in obesity, including inflammation, oxidative stress, insulin resistance, altered lipid and cholesterol homeostasis, which may result in neuroinflammation, altered brain insulin signaling, amyloid-beta (Aβ) deposition and neuronal cell death. Since obesity is associated with functional and morphological alterations in the adipose tissues, the resulting peripheral immune response augments the development and progression of cognitive decline and increases susceptibility of neurodegenerative disorders, such as Alzheimer's Disease (AD) and Parkinson's Disease (PD). Studies have also elucidated an important role of high fat diet in the exacerbation of these clinical conditions. However, the underlying factors that propel and sustain this obesity associated cognitive decline and neurodegeneration, remains highly elusive. Moreover, the mechanisms linking these phenomena are not well-understood. The cumulative line of evidence have demonstrated an important role of microRNAs (miRNAs), a class of small non-coding RNAs that regulate gene expression and transcriptional changes, as biomarkers of pathophysiological conditions. Despite the lack of utility in current clinical practices, miRNAs have been shown to be highly specific and sensitive to the clinical condition being studied. Based on these observations, this review aims to assess the role of several miRNAs and aim to elucidate underlying mechanisms that link obesity with cognitive decline and neurodegenerative disorders. Furthermore, this review will also provide evidence for the effect of dietary modulation which can potentially ameliorate cognitive decline and neurodegenerative diseases associated with obesity.

Systemic infection and symptom development of agro-inoculated cDNA clone of cherry rusty mottle-associated virus in sweet cherry (Prunus avium)

Cherry rusty mottle-associated virus (CRMaV), which belongs the genus Robigovirus of the family Betaflexiviridae, is strongly associated with cherry rusty mottle disease of sweet cherry, Prunus avium. Here, we report on the successful development of an Agrobacterium-based inoculation system for a cloned CRMaV cDNA construct. Agro-inoculation of virus-free cherry rootstock 'Krymsk6' [P. cerasus x (P. cerasus x P. maackii)] resulted in the development of chlorotic yellow mottle symptoms on systemic leaves beginning at 50 days post inoculation. The presence of CRMaV in 'Krymsk6' agro-inoculated plants was confirmed by RT-PCR and ELISA. Subsequently, CRMaV from agro-inoculated 'Krymsk6' was graft-transmissible onto virus-free sweet cherry rootstock P. avium 'Mazzard' as evidenced by the production of typical cherry rusty mottle symptoms beginning at 35 days post grafting, and further confirmed by western blotting and RT-PCR. These results showed conclusively that CRMaV is the causal agent of cherry rusty mottle disease in sweet cherry. The reverse genetic system presented in this study can be used as a tool to investigate the molecular biology of CRMaV and also a template for infectious clone development for other viruses in the genus Robigovirus.

Predicting Nonalcoholic Fatty Liver Disease through a Panel of Plasma Biomarkers and MicroRNAs in Female West Virginia Population

(1) Background: Nonalcoholic fatty liver disease (NAFLD) is primarily characterized by the presence of fatty liver, hepatic inflammation and fibrogenesis eventually leading to nonalcoholic steatohepatitis (NASH) or cirrhosis. Obesity and diabetes are common risk factors associated with the development and progression of NAFLD, with one of the highest prevalence of these diseased conditions in the West Virginia population. Currently, the diagnosis of NAFLD is limited to radiologic studies and biopsies, which are not cost-effective and highly invasive. Hence, this study aimed to develop a panel and assess the progressive levels of circulatory biomarkers and miRNA expression in patients at risk for progression to NASH to allow early intervention strategies. (2) Methods: In total, 62 female patients were enrolled and blood samples were collected after 8–10 h of fasting. Computed tomography was performed on abdomen/pelvis following IV contrast administration. The patients were divided into the following groups: Healthy subjects with normal BMI and normal fasting blood glucose (Control, n = 20), Obese with high BMI and normal fasting blood glucose (Obese, n = 20) and Obese with high fasting blood glucose (Obese + DM, n = 22). Based on findings from CT, another subset was created from Obese + DM group with patients who showed signs of fatty liver infiltration (Obese + DM(FI), n = 10). ELISA was performed for measurement of plasma biomarkers and RT-PCR was performed for circulating miRNA expression. (3) Results: Our results show significantly increased levels of plasma IL-6, Leptin and FABP-1, while significantly decreased level of adiponectin in Obese, Obese + DM and Obese + DM(FI) group, as compared to healthy controls. The level of CK-18 was significantly increased in Obese + DM(FI) group as compared to control. Subsequently, the expression of miR-122, miR-34a, miR-375, miR-16 and miR-21 was significantly increased in Obese + DM and Obese + DM(FI) group as compared to healthy control. Our results also show distinct correlation of IL-6, FABP-1 and adiponectin levels with the expression of miRNAs in relation to the extent of NAFLD progression. (4) Conclusion: Our results support the clinical application of these biomarkers and miRNAs in monitoring the progression of NAFLD, suggesting a more advanced diagnostic potential of this panel than conventional methods. This panel may provide an appropriate method for early prognosis and management of NAFLD and subsequent adverse hepatic pathophysiology, potentially reducing the disease burden on the West Virginia population.

Therapeutic Efficacy of Antioxidants in Ameliorating Obesity Phenotype and Associated Comorbidities

Obesity has been a worldwide epidemic for decades. Despite the abundant increase in knowledge regarding the etiology and pathogenesis of obesity, the prevalence continues to rise with estimates predicting considerably higher numbers by the year 2030. Obesity is characterized by an abnormal lipid accumulation, however, the physiological consequences of obesity are far more concerning. The development of the obesity phenotype constitutes dramatic alterations in adipocytes, along with several other cellular mechanisms which causes substantial increase in systemic oxidative stress mediated by reactive oxygen species (ROS). These alterations promote a chronic state of inflammation in the body caused by the redox imbalance. Together, the systemic oxidative stress and chronic inflammation plays a vital role in maintaining the obese state and exacerbating onset of cardiovascular complications, Type II diabetes mellitus, dyslipidemia, non-alcoholic steatohepatitis, and other conditions where obesity has been linked as a significant risk factor. Because of the apparent role of oxidative stress in the pathogenesis of obesity, there has been a growing interest in attenuating the pro-oxidant state in obesity. Hence, this review aims to highlight the therapeutic role of antioxidants, agents that negate pro-oxidant state of cells, in ameliorating obesity and associated comorbidities. More specifically, this review will explore how various antioxidants target unique and diverse pathways to exhibit an antioxidant defense mechanism.

Systematic Review of Clinical Insights into Novel Coronavirus (CoVID-19) Pandemic: Persisting Challenges in U.S. Rural Population

(1) Introduction. A recent viral outbreak of novel coronavirus (CoVID-19) was declared as a pandemic by the World Health Organization (WHO) due to its global public health concern. There has been an aggressive growth in the number of emerging cases suggesting rapid spread of the virus. Since the first reported case of CoVID-19, there has been vast progress in understanding the dynamics of CoVID-19. However, there is an increasing evidence of epidemiological disparity in disease burden between urban and rural areas, with rural areas having minimal pandemic preparedness and their own healthcare challenges. Therefore, this review aims to provide insight on the pathogenesis and the transmission dynamics of CoVID-19 along with pharmacological and non-pharmacological intervention strategies to mitigate the clinical manifestation of this virus. This review also aims to assess existing challenges of the CoVID-19 pandemic in rural areas based on past pandemic experiences and the effect on rural population. (2) Methods. A literature review was conducted using databases such as PubMed, Science Direct, Academic Search Premier, ProQuest, and Google Scholar, along with information from governmental organizations such as Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO). (3) Results. The causative virus, with its likely zoonotic origin, has demonstrated high pathogenicity in humans through increasing human-to-human transmission leading to extensive mitigation strategies, including patient quarantine and mass “social distancing” measures. Although the clinical manifestation of symptoms is mild in majority of the virus-inflicted population, critical patients may present with pneumonia and acute respiratory distress syndrome, exacerbated by pre-existing comorbidities, eventually leading to death. While effective coronavirus disease (CoVID-19)-specific vaccines and drugs are under clinical trials, several pharmacological and non-pharmacological interventions have been adapted to manage symptoms and curtail the effect of the virus to prevent increasing morbidity and mortality. Several persisting challenges have been noted for mitigating CoVID-19 in rural areas, including the poor healthcare infrastructure, health literacy, pandemic preparedness along with the fact that majority of rural population are frail subjects with pre-existing comorbidities. (4) Discussion. The increasing rate of incidence of CoVID-19 presents its own challenges, burdening healthcare institutions and the global economy, and impacting the physical and mental health of people worldwide. Given the clinical insights into CoVID-19 and the challenges presented in this review for the U.S. rural population, mitigation strategies should be designed accordingly to minimize the morbidity and mortality of this contagion.

Mechanistic Insight of Na/K-ATPase Signaling and HO-1 into Models of Obesity and Nonalcoholic Steatohepatitis

Obesity is a multifaceted pathophysiological condition that has been associated with lipid accumulation, adipocyte dysfunction, impaired mitochondrial biogenesis and an altered metabolic profile. Redox imbalance and excessive release of inflammatory mediators have been intricately linked in obesity-associated phenotypes. Hence, understanding the mechanisms of redox signaling pathways and molecular targets exacerbating oxidative stress is crucial in improving health outcomes. The activation of Na/K-ATPase/Src signaling, and its downstream pathways, by reactive oxygen species (ROS) has been recently implicated in obesity and subsequent nonalcoholic steatohepatitis (NASH), which causes further production of ROS creating an oxidant amplification loop. Apart from that, numerous studies have also characterized antioxidant properties of heme oxygenase 1 (HO-1), which is suppressed in an obese state. The induction of HO-1 restores cellular redox processes, which contributes to inhibition of the toxic milieu. The novelty of these independent mechanisms presents a unique opportunity to unravel their potential as molecular targets for redox regulation in obesity and NASH. The attenuation of oxidative stress, by understanding the underlying molecular mechanisms and associated mediators, with a targeted treatment modality may provide for improved therapeutic options to combat clinical disorders.

Attenuation of high glucose induced apoptotic and inflammatory signaling pathways in RIN-m5F pancreatic β cell lines by Hibiscus rosa sinensis L. petals and its phytoconstituents

ETHNOPHARMACOLOGICAL RELEVANCE

Hibiscus rosa sinensis petals possess wide range of pharmacological properties, with remarkable nutritional values. Diabetes is one of the most devastating diseases affecting the world today. A few side effects associated with the use of insulin and oral hypoglycemic agents prompted us to search new bioactive principles from antidiabetic plants used in traditional medicine.

AIM OF THE STUDY

The anti-diabetic therapeutic potential of the flavonoids rich ethyl acetate fraction of Hibiscus rosa sinensis petals (EHRS) was evaluated.

MATERIALS AND METHODS

High glucose (25 mM) induced apoptotic model of diabetes in RIN-m5F pancreatic β-cells was used for the study.

RESULTS

EHRS elevated the release of insulin in pancreatic cells and modulated apoptotic signaling cascades. It significantly reduced NF-κB nuclear translocation, thereby down-regulated the expressions of major inflammatory cytokines and up-regulated expressions of pancreatic β-cell functional genes such as, foxO-1, Ucn-3, Pdx-1, MafA and Nkx6.1. On comparison with its constituent phytochemicals, superior protective effect shown by EHRS may be due to the additive action of these phytoconstituents.

CONCLUSIONS

Results of the present study suggest hibiscus petals as a natural source and functional food of potential therapeutics to protect pancreatic β-cells in experimental diabetes mellitus.

High throughput sequencing reveals a novel fabavirus infecting sweet cherry

The genus Fabavirus currently consists of five species represented by viruses that infect a wide range of hosts but none reported from temperate climate fruit trees. A virus with genomic features resembling fabaviruses (tentatively named Prunus virus F, PrVF) was revealed by high throughput sequencing of extracts from a sweet cherry tree (Prunus avium). PrVF was subsequently shown to be graft transmissible and further identified in three other non-symptomatic Prunus spp. from different geographical locations. Two genetic variants of RNA1 and RNA2 coexisted in the same samples. RNA1 consisted of 6,165 and 6,163 nucleotides, and RNA2 consisted of 3,622 and 3,468 nucleotides.

High-Throughput Sequencing Identifies Novel Viruses in Nectarine: Insights to the Etiology of Stem-Pitting Disease

Recent studies have shown the superiority of high-throughput sequencing (HTS) technology over many standard protocols for pathogen detection. HTS was initiated on fruit tree accessions from disparate sources to improve and advance virus-testing procedures. A virus with genomic features resembling most closely that of the recently described Nectarine stem-pitting-associated virus, putative member of genus Luteovirus, was found in three nectarine trees (Prunus persica cv. nectarina), each exhibiting stem-pitting symptoms on the woody cylinder above the graft union. In these samples, HTS also revealed the presence of a coinfecting virus with genome characteristics typical of members of the genus Marafivirus. The same marafivirus- and luteovirus-like viruses were detected in nonsymptomatic nectarine and peach selections, indicating only a loose relationship between these two viruses with nectarine stem-pitting disease symptoms. Two selections infected with each of these viruses had previously tested free of known virus or virus-like agents using the current biological, serological, and molecular tests employed at the Clean Plant Center Northwest. Overall, this study presents the characterization by HTS of novel marafivirus- and luteovirus-like viruses of nectarine, and provides further insights into the etiology of nectarine stem-pitting disease. The discovery of these new viruses emphasizes the ability of HTS to reveal viruses that are not detected by existing protocols.

Hibiscus rosa sinensis Linn. Petals Modulates Glycogen Metabolism and Glucose Homeostasis Signalling Pathway in Streptozotocin-Induced Experimental Diabetes

The prevalence of diabetes mellitus is becoming more and more serious and reaches epidemic proportions worldwide. Scientific research is constantly looking for new agents that could be used as dietary functional ingredients in the fight against diabetes. The objective of the present study was to evaluate the effect of ethyl acetate fraction of Hibiscus rosa sinensis Linn. petals on experimental diabetes at a dose of 25 mg/kg body weight and it was compared with standard anti-diabetic drug metformin. The elevated levels of serum glucose (398.56 ± 35.78) and glycated haemoglobin (12.89 ± 1.89) in diabetic rats were significantly decreased (156.89 ± 14.45 and 6.12 ± 0.49, respectively) by Hibiscus rosa sinensis petals (EHRS) administration. Hepatotoxicity marker enzyme levels in serum were normalized. The fraction supplementation restored the glycogen content by regulating the activities of glycogen metabolizing enzymes. It significantly modulated the expressions of marker genes involved in glucose homeostasis signalling pathway. Histopathological analysis of liver and pancreas supported our findings. The overall effect was comparable with metformin. Hence, our study reveals the role of hibiscus petals for alleviation of diabetes complications, thus it can be propagated as a nutraceutical agent.

Selenium downregulates RAGE and NFκB expression in diabetic rats

Diabetes is one of the leading causes of death in developed and developing countries. Oxidative stress has been proposed to play a crucial role in the pathogenesis of diabetic vascular complications. In recent years, selenium has been shown to mediate a number of insulinlike actions in a dose-dependent fashion both in vitro and in vivo. In this study, the effect of selenium as sodium selenite was investigated in streptozotocin-induced diabetic rats at the dose of 1 μg sodium selenite/kg body weight. Selenium supplementation restored the streptozotocin-induced alterations in the activities of antioxidant enzymes, decreased the serum glucose level, glycated hemoglobin content as well as the levels of lipid peroxidation products, and downregulated the expressions of both NFkB and RAGE. The histopathological studies also reinforce our findings. Hence, selenium has a protective role in streptozotocin-induced diabetes mellitus.

The spectrum of histologically diagnosed malignant neoplasms in Sabah, 1983-1988

Malignant neoplasms diagnosed histologically in the state of Sabah during the period November 1983 to October 1988 were analysed to determine the distribution of malignant neoplasms according to site, age, sex and major ethnic groups. The five commonest malignant neoplasms in males were carcinomas of the nasopharynx, stomach, skin, lung and liver. In females the five commonest malignant neoplasms were carcinomas of the cervix uteri, breast, ovary, thyroid and skin. There was variation in these frequencies among the major ethnic groups. The most striking of these was the high frequency of nasopharyngeal carcinoma among Kadazan and Chinese males but not in males of the other indigenous groups. A significant number of patients with nasopharyngeal carcinoma was found in the younger age groups and most of the patients in the younger age groups were Kadazans. A relatively high frequency of carcinoma of the stomach, skin and liver was seen among Kadazans and other indigenous groups while carcinoma of the lung was seen relatively frequently among Chinese males. Among females carcinomas of the breast and cervix uteri were the most frequent malignant neoplasms in all the main ethnic groups. Possible reasons for these findings are discussed.

Detection of Helicobacter pylori from endoscopic biopsies and the biochemical characteristics of these isolates

Helicobacter pylori (formerly Campylobacter pylori) has been recently described as a gastritis-associated bacterium. We examined endoscopic biopsies of 100 patients with dyspepsia and found H. pylori in the gastric antrum of 34 (34%) by either culture, urease tests and/or histology. Thirty-one out of 41 patients (75.6%) confirmed to have chronic active gastritis histologically had H. pylori in their gastric antrum compared to 3 out of 59 patients (5.1%) with dyspepsia but normal histology (p less than 0.01). Histological examination, using gram stain and the Warthin-Starry Silver stain, detected 29 of the 34 positive cases (85.3%); urease test, 26 cases (76.5%) and culture, 22 cases (64.7%). A combination of histological examination and urease test increased the detection rate to 97.1%. Therefore we felt that for the detection of H. pylori in endoscopic biopsies, culture, which is time consuming and expensive, is not necessary in routine diagnosis as it did not improve the diagnostic rate over a combination of histology and urease test. A comparative study on three media (blood agar, chocolate agar and Skirrow's agar) used in the isolation of the organism showed that non-selective blood agar and chocolate agar were superior to Skirrow's agar. The strains isolated appeared to be homogeneous in their morphological and biochemical characteristics.

Distended oesophagus as a cause of bilateral recurrent laryngeal nerve palsy

We report an unusual case of bilateral recurrent laryngeal nerve palsy caused by gross oesophageal distension due to achalasia.