Abstract TP208: Prevalence Of Adverse Cerebrovascular Events In Hypertrophic Cardiomyopathy Patients With And Without Atrial Fibrillation: A Systematic Review And Meta-analysis

Introduction: Hypertrophic cardiomyopathy (HCM) predisposes to adverse cerebrovascular events (ACEs) including ischaemic stroke, transient ischaemic attack (TIA), thromboembolic event (TEE) and peripheral embolism (PE). Concomitant atrial fibrillation (AF), which is more prevalent in the HCM population, confers even higher risk. Our aims are to report the prevalence of ACEs in HCM patients and to determine the additional clinical risks of AF on the prognosis of this population.

Methods: A systematic literature search was performed on PubMed, Scopus, Embase/ Ovid and Cochrane library from inception to 20 th March 2021. No limitations on language or date of publication were applied. The primary outcome of this review was to examine and compare the prevalence of ischaemic stroke in the HCM population with or without AF. Secondary outcomes were to identify their risk of non-stroke clinical outcomes such as TIA, non-specified TEE and PE. Non-specified TEE in our paper only referred to thromboembolic events whereby their types were not specified in the included studies. Meta-analysis was performed using StataSE 16 software, and heterogeneity was assessed using I 2 test.

Results: A total of 713 studies were identified, and 35 articles with 42,570 patients were included. The pooled prevalence of stroke/ TIA was 7.45% (95% confidence interval [CI] 5.80 - 9.52, p = 0.000) across 24 studies in the overall HCM population of 37,643 patients. AF contributed to a significantly higher risk of non-specified TEE (Risk ratio [RR] 4.49, 95% CI 1.88 - 10.73, p = 0.0007, I 2 = 87.0) and total stroke/ TIA (RR 3.26, 95% CI 1.75 - 6.08, p = 0.0002, I 2 = 76.0) in our study population. Within the apical HCM (ApHCM) population, the prevalence of stroke/ TIA was 9.30% (95% CI 6.64 - 12.87, p = 0.316).

Conclusion: Our study concludes that concomitant AF diagnosis increases the risk of developing thromboembolic events and the stroke-related mortality rate. Although the prevalence of stroke/ TIA in the ApHCM subtype was slightly higher than the overall HCM population, further studies investigating the clinical outcomes of HCM subtypes are warranted.

Abstract 25: Left Atrial Volume Index is Associated With Atrial Fibrillation and Recurrent Stroke in Embolic Stroke of Undetermined Source (ESUS)

In ESUS, the relationship between atrial cardiopathy, occult AF and embolic stroke risk remains unclear. Studies suggest that left atrial volume index (LAVi) may be a better estimate of atrial cardiopathy than LA diameter. We explored LAVi as a marker of occult AF detection and ischemic stroke recurrence.

Methods: From 2015-2017, consecutive ESUS patients diagnosed based on consensus criteria were studied. LAVi was measured using the Biplane Area-Length Method on TTE by trained cardiologists. Clinical outcomes measured were occult AF detection and ischemic stroke recurrence in a time-to-event analysis. Kaplan-Meier curves were constructed to compare outcomes in those with high versus low LAVi at optimized cut-off values.

Results: 199 consecutive ESUS patients were followed up for 2.2±1.0 years. 9 patients were excluded due to technically inadequate views. Increased LAVi was associated with AF detection (36.63mL/m 2 ± 12.2 vs 26.93mL/m 2 ± 9.6) and stroke recurrence (32.13mL/m 2 ± 9.3 vs 27.23mL/m 2 ± 10.1). On multivariate regression adjusting for age, sex, hypertension and diabetes mellitus, LAVI was independently associated with AF detection (OR 1.08, CI 95% 1.03-1.14; p=0.003) and stroke recurrence (OR 1.05, CI 95% 1.01-1.10; p=0.026). Kaplan-Meier curves showed significant differences in occult AF (log-rank 8.67, p=0.003) and stroke recurrence (log-rank 5.31, p=0.021) between high (>27.7ml/m 2 ) and low LAVi (≤27.7ml/m 2 ) groups.

Conclusion: Increased LAVi in ESUS patients was associated with AF detection and stroke recurrence, suggesting that this may be a useful echocardiographic marker to identify high-risk patients who may potentially benefit from anticoagulation.

Association between KCNQ1 genetic variants and obesity in Chinese patients with type 2 diabetes

AIMS/HYPOTHESIS

There is evidence of overlap between susceptibility loci for type 2 diabetes and obesity. The aim of this study is to explore the association between the established type 2 diabetes locus KCNQ1 and obesity in Han Chinese.

METHODS

We recruited 6,667 and 6,606 diabetic case-control samples from Shanghai and Hong Kong, respectively. Of the samples, 7.5% and 6.3% were excluded because of genotyping failure or data missing in the association analyses of rs2237892 and rs2237895 with obesity/BMI, respectively.

RESULTS

We found that rs2237892 was associated with lower BMI and lower incidence of overweight/obesity in diabetic patients from Hong Kong (BMI, β = -0.0060 per diabetes risk C allele for log(10)BMI [95% CI -0.0088, -0.0032; p = 2.83 × 10(-5)]; overweight/obesity, OR 0.880 for C allele [95% CI 0.807, 0.960; p = 0.004]) and in the meta-analysis of cases from the two regions (BMI, combined β = -0.0048 per C allele for log(10)BMI [95% CI -0.0070, -0.0026; p = 2.20 × 10(-5)]; overweight/obesity, combined OR 0.890 for C allele [95% CI 0.830, 0.955; p = 0.001]). rs2237895 was also related to decreased BMI (combined β = -0.0042 per diabetes risk C allele for log(10)BMI [95% CI -0.0062, -0.0022; p = 4.30 × 10(-5)]). A significant association with waist circumference was detected for rs2237892 in the pooled analyses (β = -0.0026 per C allele for log(10)[waist circumference] [95% CI -0.0045, -0.0007; p = 0.007]). However, neither an association with the risk of being overweight or obese nor associations with quantitive traits were detected for rs2237892 or rs2237895 in controls.

CONCLUSION

Our findings indicate that KCNQ1 is associated with obesity in Chinese patients with type 2 diabetes.

Lepeophtheirus simplex sp. n., a caligid copepod (Siphonostomatoida) parasitic on "botete" (bullseye puffer, Sphoeroides annulatus) in Sinaloa, Mexico

A new species of caligid copepod, Lepeophtheirus simplex sp. n., parasitic on bullseye puffer, Sphoeroides annulatus (Jenyns) in Sinaloa, Mexico is described. The new species is distinguished from its congeners by the possession of (1) a maxillule with simple dentiform process; (2) a sternal furca with sharply pointed, curved tines; (3) a 2-segmented exopod of leg 3 with simple, slender spine on proximal segment; (4) a 3-segmented exopod of leg 4 with a long proximal, outer spine; and (5) the terminal claw of male antenna with a large, tridentate, medial protuberance.

Purulent and constrictive pericarditis arising from a staphylococcal lumbar infection

A 78-year-old man was admitted to the hospital for evaluation and treatment of anasarca secondary to staphylococcal purulent pericarditis. One month earlier he had undergone a lumbar laminectomy that was complicated postoperatively by a lumbar abscess that was not clinically apparent. The infection subsequently spread to the pericardium. Despite aggressive therapy that included therapeutic pericardiocentesis, drainage of pericardial fluid, and prolonged intravenous antibiotic therapy, the patient returned 2 weeks after discharge from the hospital with complicating constrictive pericarditis. Pericardiectomy was performed, resulting in complete relief of the patient's symptoms.

Species of Caligus Müller, 1785 (Copepoda: Caligidae) parasitic on marine fishes of Taiwan

Six species of copepods of the genus Caligus (Caligidae, Siphonostomatoida) parasitic on marine fishes of Taiwan are reported. They are: C. absens n. sp. from Priacanthus blochii and P. macracanthus; C. epinepheli Yamaguti, 1936 from Scolopsis vosmeri; C. kanagurta Pillai, 1961 from Decrapterts kurroides; C. laticaudus Shiino, 1960 from Lutjanus vitta and Parapristiopoma trilineatum; C. nengai Rangnekar, Rangnekar & Murti, 1953 from Triacanthus biaculeatus; and C. rotundigenitalis Yü, 1933 from Drepane punctata, Liza macrolepis and Terapon jarbua. C. distortus Pillai & Natarajan, 1977 is relegated to a synonym of C. nengai and C. multispinosus Shen, 1957 reported by Lin et al. (1994) from the cultured sea bream Acanthopagrus schlegeli is a misidentification for C. rotundigenitalis Yü, 1933.

Identification of factors from rat neutrophils responsible for cytotoxicity to isolated hepatocytes

Activated polymorphonuclear neutrophils (PMNs) have been shown to be cytotoxic to rat hepatic parenchymal cells in vitro. This cytotoxicity could be observed without direct cell-cell contact, since the conditioned medium from PMNs activated with formyl-Met-Leu-Phe (fMLP) was effective in hepatocyte killing. To identify the toxic factor(s) released by PMNs, degranulation was induced by fMLP in PMNs pretreated with cytochalasin B. The contents released from the phagocytes were subjected to gel filtration on a Sephadex G-100 column. Resulting fractions were tested for cytotoxicity to isolated hepatocytes by using release of alanine aminotransferase as a marker for hepatocyte injury. Cytotoxicity was associated with fractions containing cathepsin G and elastase and not with other fractions, including those containing myeloperoxidase. The former two enzymes were purified to homogeneity with a carboxymethyl cellulose column. Each of these enzymes demonstrated concentration-dependent cytotoxicity to hepatocytes at concentrations > 2 microgram/mL. Moreover, they exhibited an additive cytotoxic effect. Effective concentrations for the combined cathepsin G and elastase in the incubation mixture were similar to the concentrations of these enzymes in PMN-conditioned medium that produced cytotoxicity to hepatocytes. Cytotoxicity of either purified enzyme or of conditioned medium could be prevented by plasma alpha-1-antitrypsin or soybean trypsin-chymotrypsin inhibitor, which were also potent inhibitors of enzymic activity of both cathepsin G and elastase. By contrast, the serine protease inhibitors, aprotinin and 4-(2-aminoethyl)-benzene-sulfonyl fluoride, were less effective in inhibiting cathepsin G and elastase activities as well as cytotoxicity caused by the purified proteases or PMN-conditioned medium. These results support the hypothesis that cathepsin G and elastase are important mediators of hepatic parenchymal cell killing produced by activated PMNs in vitro.

Presence of gonadotropin-releasing hormone (GnRH) receptor mRNA in rat myenteric plexus cells

Idiopathic neuromuscular disease of the gastrointestinal tract (functional bowel disease) is thought to result from the malfunction of neurons within the enteric nervous system. Gonadotropin-releasing hormone (GnRH) analogs have recently been shown to organize the disordered motility patterns typical in these patients and to produce significant, long-term symptomatic improvement. To determine whether GnRH analogs might bind to an endogenous enteric nervous system GnRH receptor, reverse transcription-polymerase chain reaction (RT-PCR) was performed using cultured neonatal rat enteric neuron RNA and rat GnRH receptor primers. A PCR product of the predicted size was cloned and nucleotide sequence analysis demonstrated that the myenteric plexus PCR product encoded a portion of the GnRH receptor sequence previously identified in rat pituitary. These results suggest that cells in the myenteric plexus express GnRH receptors that may bind exogenously administered GnRH analogs. The expression of GnRH receptors in enteric neurons would provide an explanation for the effectiveness of GnRH analogs in treatment of idiopathic neuromuscular disease of the gastrointestinal tract.

Effect of glutathione depletion on haemoglobin and membrane integrity of red blood cells of rats

The effects of streptozocin (streptozotocin) and water-soluble menadione (menadione bisulphite, sodium salt) on the haemoglobin content and membrane integrity of red blood cells were investigated. Both menadione bisulphite and streptozocin significantly depleted glutathione but menadione bisulphite was much more effective in reducing glutathione than was streptozocin. Menadione bisulphite, at concentrations above 0.1 mM, caused substantial conversion of oxygenated haemoglobin into methaemoglobin while streptozocin did not alter the haemoglobin content of the red blood cells at concentrations of up to 100 mM. Both agents demonstrated only a modest ability to haemolyse the red blood cells, even at concentrations up to 300 mM. These results suggest that depletion of glutathione by menadione causes the conversion of oxyhaemoglobin to methaemoglobin. In contrast, streptozocin-induced glutathione depletion does not seem to be well correlated with alterations in haemoglobin content.

Origin and evolution of the parasitic cyclopoid copepods

Six of the 10 recognised families of the order Cyclopoida are parasitic, with 4 of them occurring on marine invertebrates and the remaining 2 on freshwater gastropods and fishes, respectively. A cladistic analysis of the 10 families indicates that evolution of parasitism occurred twice in the history of the cyclopoids. The first attempt was made by the marine epibenthic ancestors seeking food and shelter in sessile tunicates--the ascidians. This event led to the evolution of 2 ascidicolous families: Archinotodelphyidae and Notodelphyidae. The descendant of this lineage had also invaded the mantle cavity of marine bivalve molluscs, eventually leading to the evolution of the Mantridae. The second attempt for the parasitic mode of life was launched by the ancestor which was the sister group of the ancestral cyclopoids--the most successful family of freshwater copepods. This ancestral stock, while living in the coastal zone, split into 2 groups: one group stayed behind in the ocean and colonised again the ascidians; the other groups invaded freshwater and evolved into the fish-parasitising Lernaeidae and the gastropod-parasitising Ozmanidae.

Acute intestinal pseudo-obstruction due to malignant thymoma

Acute intestinal pseudo-obstruction has been associated with various diverse aetiologies, including several types of malignancies. Malignant thymoma has never been reported before as a cause of acute intestinal pseudo-obstruction. We report here a case of malignant thymoma presenting as acute intestinal pseudo-obstruction. Existing literature on malignant causes of intestinal pseudo-obstruction is also reviewed and discussed.

Determination of organic pollutants in reagent water by liquid-solid extraction followed by supercritical fluid elution

A selected group of polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides, and phthalate esters in reagent water containing no particulate matter were separated and identified by liquid-solid extraction and supercritical fluid extraction (SFE). The water sample is first passed through a cartridge or disk containing a solid matrix coated with a chemically bonded C18 organic phase capable of extracting those organic compounds. The cartridge or the disk is then eluted with supercritical carbon dioxide to remove the compounds from the sorbent. Finally, the extract is injected into a capillary column gas chromatographic/quadruple mass spectrometric system. The precisions, percent recoveries of analytes using solvent elution, and percent recoveries using SFE are compared. The total analysis time is greatly reduced by using disk extraction and SFE in place of cartridge extraction and liquid-solvent elution. In addition, the waste solvent generated was minimized by using SFE.

Mass transport and calibration in liquid chromatography particle beam mass spectrometry

Differences in the designs of two liquid chromatography particle beam mass spectrometry systems result in differences in the transport of ammonium acetate and differences in ion abundance-enhancing carrier effects. The effect of mobile phase composition, especially the proportion of water in the mobile phase, on transport efficiency is described. Instrument detection limits for 12 compounds with two different interface designs are presented. The calibrations are generally nonlinear explained in terms of mass transport effects and supported by experiments with isotopically labeled species that coelute with the native species. Summary results of a small multilaboratory study are presented. Calibration with isotopitally labeled internal standards is recommended for real-world environmental samples.

A randomized clinical trial of 10% pentastarch (low molecular weight hydroxyethyl starch) versus 5% albumin for plasma volume expansion after cardiac operations

Pentastarch is a hydroxyethyl starch similar to hetastarch, but with a lower average molecular weight (264,000 versus 450,000) and fewer hydroxyethyl groups (molar substitution ratio = 0.45 versus 0.70). These characteristics result in enhanced enzymatic hydrolysis, faster renal elimination (initial intravascular half-life = 2.5 versus 25.5 hours), and less effect on coagulation. We report on a randomized clinical trial comparing the clinical efficacy and safety of 10% pentastarch (group P) for plasma volume expansion after cardiac operations with that of 5% serum albumin (group A). During the first 24 hours after arrival of the patient in the intensive care unit, colloid was infused to maintain a cardiac index of 2.0 L/m2 or more and a mean arterial pressure within 10% of the preinduction value. Group P (n = 50) received 1706 +/- 393 ml of colloid (mean +/- standard deviation) during this period, and group A (n = 44), 1794 +/- 341 ml (p = no significant difference). Hemodynamic responses to infusion were similar for both groups, although in group P a greater increase in both cardiac index (0.5 +/- 0.5 versus 0.3 +/- 0.5 L/min/m2 in group A, p less than 0.01) and left ventricular stroke work index (10.8 +/- 8.0 versus 5.8 +/- 6.0 gm-m/m2, p less than 0.01) was observed during infusion of the first 500 ml. There were no significant differences in any of the measured respiratory parameters (alveolar-arterial oxygen gradient, estimated shunt fraction, and effective pulmonary compliance). Hemodilution with colloid significantly reduced serum protein levels in group P by 24 hours postoperatively (4.0 +/- 0.6 versus 5.0 +/- 0.7 gm/dl in group A, p less than 0.05), although mean serum colloid osmotic pressure was similar (15.4 +/- 2.6 [P] versus 15.5 +/- 2.7 mmHg [A], p = no significant difference). There were no significant between-group differences in prothrombin time, activated partial thromboplastin time, platelet count, bleeding time, or coagulation factors (fibrinogen, V, VII, VIII, or IX) on postoperative days 1 and 7. Perioperative fluid balance, weight change, chest tube output, red blood, platelet, or fresh frozen plasma usage, reexploration for bleeding, and clinical outcome were also similar. These findings indicate that pentastarch is as safe and effective s 5% albumin for plasma volume expansion after cardiac operations with no apparent adverse effects on coagulation. If commercially available at a lower cost than albumin, it would appear to be a reasonable first choice for colloid therapy in this setting.

Copepods of the Family Chondracanthidae Parasitic on Australian Marine Fishes

Three species of chondracanthid copepods are described from Australian marine fishes. They are Acanthochondria diastema Kabata, 1965 from Platycephalus sp.; Lagochondria nana gen. & sp. nov. from Callionymus sp.; and Apodochondria medusae gen. & sp. nov. from Neosebastes pandus. The first and last species were found in the collection of the South Australian Museum and the second species was collected from the Arafura Sea.

Collaborative study of reference vinyl chloride charcoal tubes

The reference vinyl chloride charcoal tubes generated by a permeation technique are evaluated by collaborative testing. The statistical analysis of Youden's method provides an estimate of replication error, sample generation error, and interlaboratory error.

Copepods of the family Chondracanthidae (Cyclopoida) parasitic on South African marine fishes

Six species of South African parasitic copepods belonging to the family Chondracanthidae were restudied. A redescription was given of Acanthochondria lepidionis, Ghondracanthus colligens and Ch. neali. Ch. lophii reported by Barnard (1955a) is actually a new species; it was named Ch. barnardi and redescribed. Ch. congiopodi Barnard, 1955, is conspecific with Ch. tuberculatus Nordmann, 1832. A redescription of this species was given based on Barnard's collection. Ch. merluccii was only mentioned and not redescribed.