Association of left atrial ejection fraction and cardiovascular outcomes in Asian patients with hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme

Background

The optimal method of risk stratification of hyp­ertrophic cardiomyopathy (HCM) patients, especially in the Asian population, is unknown. Left atrial ejection fraction (LAEF) is an emerging risk marker for cardiovascular outcomes. This study aimed to investigate whether LAEF was associated with cardiovascular outcomes in Asian patients with HCM.

Methods

This was a retrospective cohort study performed in a tertiary academic centre involving 291 consecutive patients diagnosed with HCM between 2010 and 2017. We collected the relevant clinical characteristics of these patients and retrospectively analysed the index transthoracic echocardiograms for novel left atrial indices including LAEF. We obtained the maximum (LAVmax) and minimum left atrial volumes (LAVmin) using the biplane method of disks in apical 4- and 2-chamber views. LAEF was derived by dividing the difference between LAVmax and LAVmin by LAVmax. We assessed the patients for outcomes of (1) heart failure requiring admission, and (2) a composite of adverse outcomes including all-cause mortality, ventricular tachycardia / ventricular fibrillation (VT/VF) events, appropriate device therapy if an implantable cardioverter defibrillator (ICD) was implanted, stroke and heart failure hospitalization.

Results

The patients had a mean age of 59.0 ± 16.7 years-old at diagnosis and had a male preponderance (71.2%). The most common comorbidities were hypertension, diabetes mellitus and ischemic heart disease. On univariable logistic regression analysis, maximum and minimum left atrial volume index (LAVI) as well as LAEF showed a significant association with heart failure and the predefined composite outcome. On Cox regression analysis adjusting for variables of age, sex, left ventricular ejection fraction (LVEF), left ventricular maximal wall thickness >30mm, significant left ventricular outflow tract (LVOT) gradient of > 30mmHg and more than moderate mitral regurgitation, maximum and minimum LAVI as well as LAEF retained an association with heart failure admission but only minimum LAVI and LAEF were associated with the composite outcome [(OR 0.019, 95% CI 0.02-0.230, p=0.002), (OR 0.226, 95% CI 0.053-0.960, p=0.044), (OR 1.030, 95% CI 1.016-1.045, p<0.001), and (OR 1.016, 95% CI 1.005-1.026, p=0.004) respectively].

Conclusion

LAEF was an independently associated with congestive heart failure as well as a composite of adverse outcomes in Asian patients with HCM.

[Willingness and influencing factors related to "centralized slaughtering, fresh poultry listing and marketing" strategy among the household chefs in Guangzhou]

Objective: To study the willingness and influence factors related to "centralized slaughtering, fresh poultry listing and marketing" strategy, among the household chefs, and provide reference for government to adjust and optimize the strategy on avian influenza prevention. Methods: According to the geographical characteristics and regional functions, 6 'monitoring stations' were selected from 12 residential districts of Guangzhou, respectively. Another 21 meat markets which selling live poultry, were selected in each station and 5 household chefs of each market were invited to attend a face to face interview. Basic information, personal cognitive, willingness and influencing factors to the policy were under study. Univariate and multivariate logistic regression methods were used. Results: A total of 664 household chefs underwent the survey and results showed that the rate of support to the "centralized slaughtering, fresh poultry listing and marketing" strategy was 44.6% (296/664). Results from the multi-factor logistic regression showed that those household chefs who were males (OR=1.618, 95% CI: 1.156-2.264, P=0.005), having received higher education (OR=1.814, 95% CI: 1.296-2.539, P=0.001), or believing that the existence of live poultry stalls was related to the transmission of avian influenza (OR=1.918, 95% CI: 1.341-2.743, P<0.001) were factors at higher risk. These household chefs also intended to avoid the use of live poultry stalls (OR=1.666, 95%CI: 1.203-2.309, P=0.002) and accept the "centralized slaughtering, fresh poultry listing and marketing" strategy. Conclusion: Detailed study on this subject and, setting up pilot project in some areas as well as prioritizing the education programs for household chefs seemed helpful to the implementation of the 'freezing-fresh poultry' policy.

[The effect of restraint stress on masseter mechanical hyperalgesia and the activity of neurons and astrocytes in the spinal trigeminal nucleus caudalis in rats]

Objective: To investigate the effect of restraint stress on masseter mechanical hyperalgesia and the activity of neurons and astrocytes in the spinal trigeminal nucleus caudalis (Vc). Methods: The animals were randomly divided into the control group, 1-, 3-, 5-, 7-, 9-, 11-and 14-day stress groups, with 10 rats in each group. The body weight increase and behavior tests were used to testify the animal model. The mechanical sensitivity of masseter of the rat before and after the stress was measured with Von Frey filaments. Histological examinations were used to evaluate the expression of neuronal c-fos and astrocytic glial fibrillary acidic protein (GFAP). Results: Restraint stress resulted in remarkable mechanical allodynia in the masseter muscle. The head withdrawal threshold was significantly lower in the 7-, 9-, 11-and 14-day stress groups ([0.071±0.011], [0.059±0.020], [0.052±0.011], [0.033±0.011] N) than that in the control group ([0.120±0.025] N) (P<0.05). Compared to the control group, the rats in the 1-day stress group showed a significant increase of c-fos in neurons of the Vc and then declined to normal level after 1 week gradually. The GFAP expression in astrocytes of the Vc was significantly increased in the 7-, 9-, 11-and 14-day stress groups (4.3±1.0, 4.5±0.6, 4.6±0.5, 4.8±1.3) compared with the control group (2.0±0.8) (P<0.05). Conclusions: Chronic restraint stress could lower the threshold of mechanical allodynia in the masseter muscle and activate the neurons and astrocytes in Vc. The activation of neurons and astrocytes plays an important role in the masseter hyperalgesia induced by restraint stress in rats.

[Clinical characteristics and prognosis in 12 patients with adult T cell leukemia/lymphoma confirmed by HTLV-1 provirus gene detection]

Objective: To analyze the clinical characteristics and prognosis of adult T cell leukemia/lymphoma (ATLL). Methods: Peripheral blood samples from patients who were suspected as ATLL from March, 2013 to July, 2015, were collected for HTLV-1 provirus genes detection in genomic DNA extraction by PCR. Cases showing positive results were confirmed as ATLL. Clinical and laboratory characteristics, therapeutic outcomes and survival evaluation were collected. Results: 12 out of 23 suspected patients were confirmedly diagnosed as ATLL through HTLV-1 provirus genes detection by PCR. Eight patients were male and four patients were female. Median age was 51 (range 28-66) years old. All of those patients came from coastal cities of Fujian province where a HTLV-1 epidemic area locates. In the subtype classification of these 12 ATLL, 11 patients were classified as acute type and one case as lymphoma type ATLL. As one of the clinical characteristics of ATLL, ' flower cells ', with typical or atypical morphology had been observed in a high rate (81.8%). Clinical symptom such as hepatomegaly, splenomegaly and lymphadenectasis were detected in most of patients, and hypercalcemia and elevated LDH were also noted commonly. The ATLL cells immunophenotype were typical, and the major subtype was CD4+ CD8- type. Confection of hepatitis B virus was detected in a high rate (54.5%). Ten patients received chemotherapy, and 2 cases in complete remission after chemotherapy received allogeneic hematopoietic stem cell transplantation. At the end of the follow-up, 7 cases died, 4 cases survived, 1 case was lost, and the median survival was 2.8 (0.9-10.8) months. We found a case had HTLV-1 provirus negative after transplantation. Conclusion: In the coastal area of Fujian Province, ATLL is not rare. Characteristics of those ATLL are typical. But prognosis is still unsatisfactory.

Induction of HSP72 in rat liver by chronic ethanol consumption combined with exercise: association with the prevention of ethanol-induced fatty liver by exercise

Ethanol-induced fatty liver in rats was attenuated by repeated running exercise, and the protective effect of exercise was associated with the synergistic expression of heat shock proteins (HSP72). Rats were placed in four groups of six. The two ethanol-fed groups of rats received a liquid diet (Lieber-DeCarli formulation) in which 36% of the calories were derived from ethanol. One group remained sedentary (S/E), whereas the other was trained to run on a rodent treadmill at a speed of 27 m/min, 1 hr/day, 5 days/week, for 7 weeks (R/E). Two other groups--one exercised as previously mentioned (R/C) and one sedentary (S/C)--received control-liquid diets in which the ethanol was isocalorically substituted with a dextran/maltose mixture. The degree of fatty infiltration in liver sections stained with hematoxylin and eosin was graded on a 0-4 scale and the data analyzed by ANOVA on ranks. Ethanol significantly induced fatty infiltration in the S/E group, whereas fatty infiltration in the livers of the R/E group was not different from the S/C group. Electrophoresis and Western blotting of liver homogenates demonstrated that HSP72 was not expressed in either the S/C or S/E groups and was only slightly expressed in the R/C group. The combination of exercise and ethanol, however, resulted in an elevated expression of HSP72 in the R/E group. The content of HSP73 was unaffected by any treatment.

Effect of alcohol on expression of heat shock protein 73 in monolayers of hepatocytes from alcohol-exposed rats

Alcohol dramatically reduced loss of heat shock proteins (HSP73) and prevented morphological damage in monolayers of hepatocytes prepared from alcohol-fed rats. The monolayers were treated with 0, 5, 25, or 100 mM alcohol and triplicate samples were assayed at 24, 48, 72, and 96 hr after exposure. The content of HSP73 was measured by PAGE electrophoresis and Western blotting with a mouse monoclonal anti-HSP70 IgG antibody. HSP72 is not expressed under these conditions. Damage to the hepatocytes, quantified by leakage of lactate dehydrogenase (LDH), was also decreased by 100 mM alcohol. Although the initial 100 mM alcohol concentration decreased logarithmically to 1.7 mM over the first 24 hr, the effect of alcohol on HSP73 loss, LDH leakage, and morphological damage was most pronounced at 96 hr.

Time course of 72-kilodalton heat shock protein induction and appearance of trifluoroacetyl adducts in livers of halothane-exposed rats

Previous studies have shown that exposure of phenobarbital-pretreated rats to halothane in 10% O2 causes centrilobular necrosis, induces expression of the 72-kDa heat shock protein (HSP72), and produces several trifluoroacetylated adducts. In the present study the time course of development of the centrilobular lesion, as measured by histochemistry, was compared with the time course of appearance of both trifluoroacetylated adducts and HSP72, as measured by Western blotting. One group of 20 rats was pretreated with phenobarbital for 5 days, whereas a second group of two rats was left as untreated controls. Ten phenobarbital-pretreated rats were exposed for 2 hr to 1% halothane in 10% O2 and 10 were exposed to 1% halothane in 20% O2. At either 2, 4, 6, or 24 hr after exposure, livers were excised and frozen without fixation. Thin sections stained with hematoxylin and eosin demonstrated that centrilobular lesions occurred at 6 hr and became extensive at 24 hr in rats pretreated with phenobarbital and exposed to 1% halothane in 10% O2. The time course of appearance of both trifluoroacetylated adducts and HSP72 was determined by Western blotting. Trifluoroacetylated adducts appeared in all rats exposed to halothane by 2 hr, lasted until 6 hr, and then diminished by 24 hr. In contrast, HSP72 was induced only in the rats pretreated with phenobarbital and exposed to 1% halothane in 10% O2. HSP72 appeared in both the nuclear and supernatant fractions at 6 hr after exposure and was intense 24 hr after exposure.

Nuclear translocation of heat shock protein 72 in liver cells of halothane-exposed rats

Immunocytochemical studies have revealed that one of the major heat shock proteins, HSP72, is induced in livers of rats that have been pretreated with phenobarbital and then administered halothane in a hypoxic gas mixture of 10% oxygen. To determine the sub-cellular localization of HSP72 in the livers of these rats 24 hr after halothane administration, cytoplasmic and nuclear fractions were prepared and separated by PAGE electrophoresis. Western blotting with a mouse monoclonal anti-HSP70 IgG antibody, which recognizes both the constitutive (HSP73) and inducible (HSP72) forms, revealed that HSP72 was induced and translocated into the nucleus in only those rats exposed to halothane under hypoxia following phenobarbital pretreatment. Nuclear translocation of HSP72 under the latter conditions was confirmed by immunocytochemical staining using gold-conjugated secondary antibodies followed by digital laser microscopy with Nomarski optics. Neither phenobarbital pretreatment alone nor phenobarbital plus hypoxia treatment induced HSP72. No alteration in amount of HSP73 was observed under any of these conditions.

Production of complement component C3 in vivo following 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been shown to decrease serum complement C3 levels in female B6C3F1 mice but failed to alter C3 production when added in vitro to either hepatoma cells (both human and mouse hepatoma cells) or mouse primary hepatocytes (Lin and White, 1993a). It has also been demonstrated that mouse liver intracellular C3 levels were not affected following TCDD exposure in vivo, while serum C3 levels were suppressed (Lin and White, 1993b). Therefore, further studies were undertaken to investigate the mechanism by which TCDD modulates newly synthesized serum C3 in vivo. Mouse serum C3 was depleted by an intravenous injection of 50 anti-complement units (ACU)/kg cobra venom factor (CVF). This dose of CVF depleted serum C3 levels to 9% of control at 24 h after treatment. Subsequently, serum C3 levels returned to 19% and 75% of the control level on d 3 and d 5. The recovery of serum C3 was then monitored following an acute oral exposure to 20 micrograms/kg TCDD. In mice exposed to both TCDD and CVF, serum C3 levels reached 15% and 69% of control on d 3 and d 5 after treatment; these results were not significantly different from those of mice treated with CVF alone. Furthermore, when the radiolabeled amino acid [3H]leucine was injected intravenously into either vehicle- or TCDD-treated mice, the incorporation of this labeled precursor into both C3 and other secreted plasma proteins was not inhibited by TCDD. These results demonstrated that TCDD did not decrease newly synthesized C3 in vivo. These studies provide additional support for the concept that TCDD does not act directly on hepatocytes to suppress C3 production. The lower serum C3 levels observed in vivo following TCDD exposure is not the result of a decrease in C3 production by hepatocytes.

Mouse Hepa 1c1c7 hepatoma cells produce complement component C3; 2,3,7,8-tetrachlorodibenzo-p-dioxin fails to modulate this capacity

Previous studies from this laboratory have shown that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) decreased complement component C3 levels in female B6C3F1 mouse serum following in vivo acute or subchronic exposure (White et al., 1986). Since TCDD is a hepatotoxic compound and more than 90% of serum C3 is produced by the liver, studies were undertaken using mouse Hepa 1c1c7 (Hepa 1) hepatoma cell line to determine if TCDD acts directly on hepatocytes to inhibit C3 production. The C3-producing capacity of Hepa 1 cells was first examined. When confluent Hepa 1 cell monolayers were cultured in 24-well plates with serum-free medium, a detectable amount of C3 (14.1 +/- 0.8 ng/ml) was secreted as early as 1 h after culture and reached a plateau at 12 h (68.3 +/- 4.9 ng/ml). Furthermore, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated that the molecular weight of C3 in culture supernatant corresponded to that present in mouse serum. Human recombinant IL-1 beta (hrIL-1 beta), a known inducer of complement C3, at doses as low as 1 unit/ml increased the C3 production to 158% of control after 24 h of incubation. The effect of hrIL-1 beta was dose dependent, and the maximum tested dose of 10 units/ml increased C3 production to 256% of control. When cells were directly exposed to TCDD at concentrations from 10(-10) to 10(-6) M, there was no inhibitory effect on production of C3. TCDD also failed to block the stimulatory effect of 10 units/ml hrIL-1 beta added to the culture 1 h later. To verify that cultured Hepa 1 cells were able to respond to TCDD, 7-ethoxyresorufin O-deethylase (EROD) activity was measured under the same conditions. TCDD dose-dependently increased EROD activity of Hepa 1 cells at 24 h following exposure. The activity reached 56.7 +/- 3.0 pmol/min/mg protein with 10(-9) M TCDD, compared with 10.7 +/- 1.7 pmol/min/mg protein of vehicle-exposed cells. Our results indicate that the direct interaction of TCDD with Hepa 1 cells does not affect their C3-producing capacity, although EROD activity, a characteristic response mediated by the cellular TCDD/Ah receptor, was induced. The lack of effect of TCDD in vitro suggests that the decrease of serum C3 levels observed in vivo may result from an indirect effect of TCDD on hepatocytes.

Modulation of liver intracellular C3 in mice by 2,3,7,8-tetrachlorodibenzo-p-dioxin

Earlier studies from this laboratory have shown that the complement system, especially the component C3, in female B6C3F1 mice is suppressed following TCDD exposure in vivo. However, the direct exposure of TCDD in vitro does not affect the C3-producing capacity of two types of hepatoma cells, as well as mouse primary hepatocytes. To investigate the effect of TCDD on C3 production by the liver following in vivo exposure, liver intracellular C3 levels and pro-C3, the precursor of the secreted C3, were examined in the present study. The results demonstrated that there was a dose-dependent increase of liver intracellular C3 levels (from 138% to 175% of control) immediately following TCDD (from 10 to 40 micrograms/kg) exposure. This increase was rapid (4 h after exposure), but transient (less than 2 h), and was not accompanied by an alteration of serum C3 levels. Studies using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that the increase in liver intracellular C3 levels resulted from, at least partially, an increase in intracellular pro-C3. Serum C3 levels did not decrease until d 3 after exposure, when both liver intracellular C3 levels and pro-C3 in TCDD-treated mice were not different from those of the control mice. These results indicated that the modulation of liver intracellular C3 by TCDD did not correlate with the suppression of serum C3 levels following exposure.

Suppression of the murine gut mucosal IgA response to cholera toxin with oral cyclosporine

The gut mucosal immune system may be a primary target for many ingested chemicals. Methods have been developed to examine the effects of chemicals on the systemic humoral immune response; however, studies to evaluate various methods of assessing the local gut mucosal immune response in a toxicology assay have been limited. The objectives of this study were to examine the effects of the known immunosuppressive compound, cyclosporine (CYS), on the generation of a cholera toxin (CT)-specific gut mucosal IgA response and evaluate the methods used to measure the gut IgA response. Groups of female B6C3F1 mice were left untreated or were treated daily, p.o., with corn oil (vehicle) or CYS at doses of 10 and 50 mg/kg for 20 days. On Days 3 and 13, mice were sensitized p.o. with CT. On Day 21, mice were terminated, gut washings were collected, and lamina propria lymphocytes were extracted from gut tissue with collagenase treatment. Cholera toxin-specific IgA in the gut washings was measured by an ELISA. The numbers of CT-specific IgA (CT-IgA) and total IgA antibody-forming cells (spot-forming cells, SFC) obtained from the lamina propria were determined by the ELISPOT method. A dose of 50 mg/kg CYS produced a significant decrease in the amount of CT-IgA in gut washings. This dose also decreased the number of cells recovered from the lamina propria by at least 50%. The amount of CT-specific SFC/million lamina propria cells decreased with a dose of 10 mg/kg CYS, whereas 50 mg/kg CYS did not alter the response.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactive effects of pertussis toxin and the phorbol ester tumour promotor, phorbol dibutyrate, on T-lymphocyte mitogenesis and the expression of phenotypic determinants

The B oligomer of pertussis toxin serves as a weak mitogen in the T lymphocyte, an effect which is associated with an early rise in cytosolic free calcium concentrations, as monitored by Fura-2 fluorescence. Upon co-administration of phorbol dibutyrate, a phorbol ester tumour promotor which activates protein kinase C, pertussis toxin-induced proliferation was synergistically enhanced, as measured by the increased uptake of [3H]thymidine, into cellular DNA. Although phorbol ester co-administration has often been associated with an inhibition of Ca2+-mobilizing pathways, phorbol dibutyrate pretreatment had no inhibitory effect on the pertussis toxin-induced calcium flux and may actually have enhanced this response slightly. Flow cytometric analysis of cell populations expanded by the combined regimen did not provide evidence for the preferential expansion of cells bearing either CD4 or CD8, the T-cell determinants representative of the helper-inducer and cytotoxic-suppressor subsets, respectively. Pertussis toxin and phorbol dibutyrate appear, therefore, to elicit polyclonal stimulation, rather than the selective activation of a given lymphocyte subset. Expression of the transferrin receptor, a marker for nutrient uptake, and CD25, the Tac component of the interleukin-2 (IL-2) receptor, was, however, synergistically enhanced in cells activated by the co-treatment procedure.

Antibody-mediated resistance against duck enteritis virus infection

Vaccination of ducks with an apathogenic strain of duck enteritis virus resulted in protection against challenge with the virulent Lake Andes strain of duck enteritis virus by intramuscular inoculation or contact exposure. Antisera produced in the vaccinated ducks were able to transfer resistance against the challenge strain to recipient ducks. Antisera against duck enteritis virus were cytotoxic for duck enteritis virus-infected duck embryo fibroblasts in the presence of guinea pig complement. These in vivo and in vitro data suggest that the humoral immune mechanism plays a role in protecting ducks from duck enteritis virus infection.

Serological survey of infectious bursal disease virus serotypes 1 and 2 in California turkeys

The prevalence of two infectious bursal disease (IBD) viruses--serotype 1, of chicken origin, and serotype 2, of turkey origin--was studied in California turkeys. Serum samples were collected from 15 turkey flocks representing nine counties. The virus-neutralization test was used. Overall, only 15% of 342 samples were positive for serotype 1, whereas 89% were positive for serotype 2. However, 12 out of 15 flocks had a least one sample positive for serotype 1, and 14 out of 15 flocks had at least one sample positive for serotype 2. Flocks with antibodies to serotype 1 had low geometric mean titers (GMTs) (1.5 to 8.8) and low-to-medium prevalence rates (5 to 53.3%). Flocks with antibodies to serotype 2 had high GMTs (36.8 to 2048) and high prevalence rates (60 to 100%). Results of this study lead us to question the efficacy of IBD vaccination in turkeys.

Active and passive immunization of ducks against duck viral enteritis

The newly isolated Sheridan-83 strain of duck enteritis virus (DEV) was apathogenic to ducks. Inoculation of ducks with this virus resulted in the production of antibodies that enabled the ducks to resist challenge with the virulent LA strain of DEV. The minimum protective dose of the Sheridan-83 virus was determined to be less than 10 TCID50. Solid immunity lasted 1-2 months. Passive transfer of antibodies to susceptible ducks also significantly protected them from lethal challenge.

Further studies on the immunization of chickens with temperature-sensitive Mycoplasma gallisepticum mutant

Newly hatched chickens were immunized with a temperature-sensitive (TS) Mycoplasma gallisepticum (MG) mutant (TS 100). Immunized chickens resisted challenge with the virulent S6 strain. The dose of TS MG needed for protection was less than 3.3 X 10(4) colony-forming units. After immunization with TS 100, chickens were subjected to a variety of virus infection and immunosuppressive treatments. Neonatal bursectomy or thymectomy, infectious bursal disease virus infection, and infectious bronchitis virus vaccination or a combination of infectious bronchitis virus and Newcastle disease virus vaccination did not contribute to the development of air-sac lesions in TS MG-immunized chickens. Infectious bronchitis virus vaccination enabled MG to migrate from the nasal cavity to the trachea but not to the air sacs. The TS MG vaccine appears to be a safe immunogen.

Immunization of chickens with temperature-sensitive mutants of Mycoplasma gallisepticum

Temperature-sensitive (TS) mutants of the S6 strain of Mycoplasma gallisepticum (MG) were used to immunize newly hatched chickens. Immunized chickens developed antibodies to the wild-type (WT) S6 strain as demonstrated by serologic tests. MG was recovered from nasal cavities but not from the lower respiratory tract of the immunized chicks. Three weeks after intranasal immunization, chickens were challenged via the air sacs with the virulent S6 strain. Immunized chickens were significantly better protected from development of air-sac lesions than were controls.