Objective To investigate the pathogenetic mechanisms leading to the development of calcific degeneration of the aortic valve in the elderly patients with particular reference to the relationship between apoptosis and calcification in the aortic valve tissue.Methods High resolution scanning and transmission electron microscopic observations of the calcified aortic valves obtained during aortic valve replacement were carried out in 10 patients with senile calcific aortic stenosis.Results　Various degrees of endothelial alterations from focal disruption of individual endothelial cells to extensive denudation of entire endothelium were observed particularly on the aortic side of the valve tissues. The apoptotic changes occurring in the nuclei of endothelial cells and fibroblasts were common findings in the calcified valve tissues. It was noteworthy that the severity of endothelial damage was closely related to apoptotic changes of the fibroblasts. Calcific deposits were frequently observed in association with the cellular fragments mainly derived from the apoptotic fibroblasts.Conclusions　Our results strongly indicate that apoptosis may play an important role in the alterations of endothelial integrity leading to the increased filtration of calcium into the deeper layer of the valve tissues. Then, the cellular degradation products and organelles extruded from the dead cells, mainly resulted from apoptosis provided the substrates for calcium binding with progressive development of calcification in the valve tissue. Although the role of apoptosis in contribution to the pathogenesis of senile calcific aortic stenosis is evident, further studies using modern molecular biotechnology are mandatory in order to clarify the mechanism for the initiation of apoptotic process in the endothelial cells and fibroblasts.

Objective To characterize ultrastructurally and biochemically catecholamine release mechanisms of cultured human pheochromocytoma cells in the basal and stimulated states.Methods The cultured pheochromocytoma cells were prepared from human adrenal pheochromocytoma tumors. Biochemical determinations of catecholamine secretion from the cultured cells were carried out in the basal and stimulated states. Transmission electron microscopy was used to observe the modes of catecholamine release from the cells without and with stimulation by depolarization of the cells with the administration of 50 mmol/L KCl.Results Biochemical determinations consistently showed spontaneous secretion of catecholamines from the cultured cells in the basal state without stimulation. Catecholamine release in a calcium-dependent manner could be enhanced in the cells in response to high extracellular potassium concentration. A series of electron microscopic observations of the cultured cells consistently disclosed the classical exocytotic profiles on the cell surface in the basal state. In addition to abundant increase in the number of classical single exocytosis, compound exocytosis was frequently observed in the stimulated cells. Furthermore, other modes of catecholamine release mechanism involving the formation of pseudopodial and/or tubule-like structures, which were different from classical exocytosis, were often present in the intensely stimulation cells. Conclusions Based on the biochemical and electron microscopic findings, we concluded: (1) classical single exocytosis is considered to be a primary mechanism responsible for spontaneous secretion of catecholamines from the cells in the basal state; (2) compound exocytosis is an essential mechanism for extruding large amounts of catecholamines in the stimulated cells; and (3) other modes of catecholamine release mechanism may operate in the cells in response to intense stimulation. These morphological data may be helpful in explanation of biochemical variability and extreme diversity of clinical manifestatons in patients with pheochromocytoma tumor.

Objective To investigate molecular events of exocytosis in cultured human pheochromocytoma cells with stimulation.Methods The cultured pheochromocytoma cells prepared from human adrenal pheochromocytoma tumor were stimulated for the release of catecholamines by depolarization with the administration of 50 mmol/L KCl. Transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HR-SEM) combined with autoradiography and cytochemistry were used to observe molecular mechanisms of exocytotic release of catecholamines from the stimulated cells labelled with 3H-noradrenaline and the filipin-treated cells.Results TEM and HR-SEM observations of the stimulated cells labelled with 3H-noradrenaline revealed that the initial exocytotic fusion pores even less than 10 nm in diameter in human pheochromocytoma cells can be clearly observed in a single lipid bilayer. Furthermore, HR-SEM examinations of the filipin-treated cells showed that the derangement of the particles of the filipin-sterol complexes (FSCs) in the fused membranes of granule and plasma membranes occurred as the exocytotic fusion pores opened. In addition, the aggreates of the FSCs particles were consistently demonstrated around the openings of the differently sized closing exocytotic pores.Conclusions Based on our results, it is suggested that the rearrangement of the sterol molecules in the fused membranes of granule and plasma membranes plays an important role in the opening and closing mechanisms of exocytotic fusion pores. We hope that morphological data obtained in this study can provide some new insights into the understanding of molecular mechanisms of exocytosis, particularly the opening and closing of exocytotic fusion pores in relation to the distribution of the membrane sterols.

Objective　To investigate the ultrastructural pathological alterations of the microvasculature and nerve fibers in the endomyocardial biopsied specimens of the left ventricular myocardium obtained from patients with idiopathic dilated cardiomyopathy and chronic heart failure.Methods　Transmission electron microscopic observations of endomyocardial biopsied specimens of the left ventricular myocardium were carried out in 10 patients with idiopathic dilated cardiomyopathy and chronic heart failure.Results　Various degrees of ultrastructural pathological alterations in the microvessels and sympathetic nerves in the diseased myocardium were consistently demonstrated in idiopathic dilated cardiomyopathy. In addition, abnormal accumulation of collagen tissue and edematous fluid were often seen in the interspace between myocardial cells and nerve endings and capillaries.Conclusions　Based on the ultrastructural pathological findings in this study, we consider that all the structures forming the muscle cells and the tissues around them, namely the microvessels and nerves may participate in the pathological process in the course of dilated cardiomyopathy. The damage of microvasculature and sympathetic nerves resulting from the underlying disease processes are considered to be an important pathogenetic mechanism responsible for progressive development of myocardial degeneration and dysfunction throughout the course of the disease. It is hoped that our data may provide some insights into the understanding of the role of microcirculation and sympathetic nerves in the etiopathogenesis of dilated cardiomyopathy.

Purpose: The objective of this study was to define the learning curve required to attain satisfactory oncologic outcomes of cervical cancer patients who were undergoing open or minimally invasive surgery for radical hysterectomy, and to analyze the correlation between the learning curve and tumor size. Materials and Methods: Cervical cancer patients (stage IA-IIA) who underwent open radical hysterectomy (n=280) or minimal invasive radical hysterectomy (n=282) were retrospectively reviewed. The learning curve was evaluated using cumulative sum of 5-year recurrence rates. Survival outcomes were analyzed based on the operation period (“learning period,” P1 vs. “skilled period,” P2), operation mode, and tumor size. Results: The 5-year disease-free and overall survival rates between open and minimally invasive groups were 91.8% and 89.0% (p=0.098) and 96.1% and 97.2% (p=0.944), respectively. The number of surgeries for learning period was 30 and 60 in open and minimally invasive group, respectively. P2 had better 5-year disease-free survival than P1 after adjusting for risk factors (hazard ratio, 0.392; 95% confidence interval, 0.210 to 0.734; p=0.003). All patients with tumors < 2 cm had similar 5-year disease-free survival regardless of operation mode or learning curve. Minimally invasive group presented lower survival rates than open group when tumors ≥ 2 cm in P2. Preoperative conization improved disease-free survival in patients with tumors ≥ 2 cm, especially in minimally invasive group. Conclusion Minimally invasive radical hysterectomy required more cases than open group to achieve acceptable 5-year disease-free survival. When tumors ≥ 2 cm, the surgeon’s proficiency affected survival outcomes in both groups.

BACKGROUND AND OBJECTIVES: Oxidative stress plays an important role in the pathogenesis of coronary atherosclerosis and spasm. We investigated whether the polymorphisms in two oxidative stress-related genes, paraoxonase and p22phox, are associated with risks of coronary artery spasm and stenosis. SUBJECTS AND METHODS: The study comprised of 116 patients with variant angina, 118 patients with coronary artery stenosis and 117 control subjects, who were all classified by coronary angiography. In all three groups, the genotype frequencies of the Q192R polymorphism of the paraoxonase gene and C242T polymorphism of the p22phox gene were analyzed, and the serum thiobarbituric acid-reactive substance concentrations measured. RESULTS: The frequency of the RR genotype of the paraoxonase Q192R polymorphism was significantly higher in patients with variant angina and coronary artery stenosis than in the control subjects (40.4% in variant angina and 37.8% in coronary artery stenosis vs. 24.7% in control, p=0.020 and 0.048, respectively). From the multivariate analysis, the odds ratio of the RR genotype was 2.240 for variant angina (95% confidence interval ; 1.012-4.956), and 2.333 for coronary artery stenosis (95% confidence interval ; 1.140-4.777), in relation to the control subjects. The thiobarbituric acid-reactive substance level was significantly higher in the RR type than in the QQ+QR types (RR vs. QQ+QR : 1.106+/-0.420 nmol/mL vs. 0.949+/-0.311 nmol/mL, p=0.028). There was no significant difference in the prevalence of the C242T polymorphism of the p22phox gene between the three groups. CONCLUSION: The RR genotype of the paraoxonase gene Q192R polymorphism was found to be an independent risk factor for both coronary spasm and stenosis.
Angina Pectoris ; Aryldialkylphosphatase* ; Constriction, Pathologic ; Coronary Angiography ; Coronary Artery Disease ; Coronary Stenosis* ; Coronary Vessels* ; Genotype ; Humans ; Multivariate Analysis ; Odds Ratio ; Oxidative Stress* ; Polymorphism, Single Nucleotide ; Prevalence ; Risk Factors ; Spasm

INTRODUCTION: The rising prevalence of multiple chronic diseases is an important public health issue as it is associated with increased healthcare utilisation. This paper aimed to explore the annual per capita healthcare cost in primary care for patients with multiple chronic diseases (multimorbidity). METHODS: This was a retrospective cohort study conducted in a cluster of public primary care clinics in Singapore. De-identified data from electronic medical records were extracted from July 2015 to June 2017. Only patients with at least 1 chronic disease were included in the study. Basic demographic data and healthcare cost were extracted. A list of 20 chronic diseases was considered for multimorbidity. RESULTS: There were 254,377 patients in our study population, of whom 52.8% were female. The prevalence of multimorbidity was 62.4%. The median annual healthcare cost per capita for patients with multimorbidity was about twice the amount compared to those without multimorbidity (SGD683 versus SGD344). The greatest percentage increment in cost was when the number of chronic diseases increased from 2 to 3 (43.0%). CONCLUSION Multimorbidity is associated with higher healthcare cost in primary care. Since evidence for the optimal management of multimorbidity is still elusive, prevention or delay in the onset of multimorbidity in the general population is paramount.
Chronic Disease ; Comorbidity ; Cross-Sectional Studies ; Female ; Health Care Costs ; Humans ; Prevalence ; Primary Health Care ; Retrospective Studies ; Singapore/epidemiology*

Leptin is a peptide hormone, which has a central role in the regulation of body weight; it also exerts many potentially atherogenic effects. Ferulic acid ethyl ester (FAEE) has been approved for antioxidant properties. The aim of this study was to investigate whether FAEE can inhibit the atherogenic effects of leptin and the possible molecular mechanism of its action. Both of cell proliferation and migration were measured when the aortic smooth muscle cell (A10 cell) treated with leptin and/or FAEE. Phosphorylated p44/42MAPK, cell cycle-regulatory protein (for example, cyclin D1, p21, p27), beta-catenin and matrix metalloproteinase-9 (MMP-9) proteins levels were also measured. Results demonstrated that leptin (10, 100 ng ml-1) significantly increased the proliferation of cells and the phosphorylation of p44/42MAPK in A10 cells. The proliferative effect of leptin was significantly reduced by the pretreatment of U0126 (0.5 muM), a MEK inhibitor, in A10 cells. Meanwhile, leptin significantly increased the protein expression of cyclin D1, p21, beta-catenin and decreased the expression of p27 in A10 cells. In addition, leptin (10 ng ml-1) significantly increased the migration of A10 cells and the expression of MMP-9 protein. Above effects of leptin were significantly reduced by the pretreatment of FAEE (1 and 10 muM) in A10 cells. In conclusion, FAEE exerts multiple effects on leptin-induced cell proliferation and migration, including the inhibition of p44/42MAPK phosphorylation, cell cycle-regulatory proteins and MMP-9, thereby suggesting that FAEE may be a possible therapeutic approach to the inhibition of obese vascular disease.
Animals ; Antioxidants/*pharmacology ; Aorta/cytology/*drug effects ; Caffeic Acids/*pharmacology ; Cell Line ; Cell Movement/*drug effects ; Cell Proliferation/*drug effects ; Leptin/*metabolism ; Matrix Metalloproteinase 9/metabolism ; Muscle, Smooth, Vascular/cytology/drug effects ; Myocytes, Smooth Muscle/cytology/*drug effects ; Rats ; beta Catenin/metabolism

Abdominal Pain ; diagnosis ; Adult ; Female ; Humans ; Sports ; Superior Mesenteric Artery Syndrome ; diagnosis ; Young Adult

BACKGROUND/AIMS: Inflammatory bowel disease (IBD) is associated with considerable impairment of patients’ health-related quality of life (HRQoL). Knowledge of factors that significantly affect IBD patients’ HRQoL can contribute to better patient care. However, the HRQoL of IBD patients in non-Western countries are limited. Hence, we assessed the HRQoL of Singaporean IBD patients and identified its determinants. METHODS: A prospective, cross-sectional study was conducted at Singapore General Hospital outpatient IBD Centre. The HRQoL of IBD patients was assessed using the short IBD questionnaire (SIBDQ), Short Form-36 physical and mental component summary (SF-36 PCS/MCS) and EuroQol 5-dimensions 3-levels (EQ-5D-3L) and visual analogue scale (VAS). Independent samples t-test was used to compare HRQoL between Crohn’s disease (CD) and ulcerative colitis (UC). Determinants of HRQoL were identified through multiple linear regression. RESULTS: A total of 195 IBD patients (103 UC, 92 CD) with a mean disease duration of 11.2 years were included. There was no significant difference in HRQoL between patients with UC and CD. Factors that significantly worsened HRQoL were presence of active disease (b=−6.293 [SIBDQ], −9.409 [PCS], −9.743 [MCS], −7.254 [VAS]), corticosteroids use (b=−7.392 [SIBDQ], −10.390 [PCS], −8.827 [MCS]), poor medication adherence (b=−4.049 [SIBDQ], −1.320 [MCS], −8.961 [VAS]), presence of extraintestinal manifestations (b=−13.381 [PCS]), comorbidities (b=−4.531 [PCS]), non-employment (b=−9.738 [MCS], −0.104 [EQ-5D-3L]) and public housing (b=−8.070 [PCS], −9.207 [VAS]). CONCLUSIONS: The HRQoL is impaired in this Asian cohort of IBD. The magnitude of HRQoL impairment was similar in UC and CD. Clinical characteristics were better determinants of patients’ HRQoL than socio-demographic factors. Recognizing the factors that impact patients’ HRQoL would improve the holistic management of IBD patients.
Adrenal Cortex Hormones ; Asian Continental Ancestry Group ; Cohort Studies ; Colitis, Ulcerative ; Comorbidity ; Cross-Sectional Studies ; Hospitals, General ; Humans ; Inflammatory Bowel Diseases ; Linear Models ; Medication Adherence ; Outpatients ; Patient Care ; Prospective Studies ; Public Housing ; Quality of Life ; Singapore