Physiologic analysis of cardiac cycle in an implantable impeller centrifugal left ventricular assist device

The purpose of this study was to determine the physiologic relationship between the cardiac cycle and the nonpulsatile impeller centrifugal Taita No.1 left ventricular assist device (T-LVAD) in a chronic animal study. The relationship of the cardiac cycle, pump flow, aortic pressure, left ventricle pressure, and pump power were analyzed by 5 phases in 4 stages. The isovolumetric ventricular phase is from mitral valve closure (MVC) to aortic valve opening (AVO) and is called Stage 1. The ejection phase is from AVO to aortic valve closure (AVC) and is called Stage 2. The isovolumetric relaxation phase is from AVC to MVC and is called Stage 3. The passive filling and atrial contraction phase is from MVC to mitral valve opening (MVO) and called Stage 4. Based on evidence from the physiologic volume change of the left ventricle, the change of pump flow of the T-LVAD in a cardiac cycle by variable voltages of pump control was evaluated using animal models. After left posteriolateral thoracotomy via the fifth intercostal space under general anesthesia, the nonpulsatile centrifugal T-LVAD was implanted into 2 healthy calves. The inflow of the T-LVAD was inserted into the left ventricle through the mitral valve via the left atrial appendage. The arterial blood pressure waveform was measured and recorded on the outflow of the T-LVAD. The 4 phases of a cardiac cycle were defined as MVC-AVO (Stage 1), AVO-AVC (Stage 2), AVC-MVO (Stage 3) and MVC-MVO (Stage 4) according to the outflow pressure of the outflow of the T-LVAD and differential pressure between the outflow and inflow of the T-LVAD. We carried out the real-time waveform measurement for electrocardiogram, the outflow pressure, the T-LVAD flow and the speed, as well as open loop and constant voltage (V). In a cardiac cycle, the sensing current of the T-LVAD was inverse to the speed. The flow of the T-LVAD at the 4 stages was measured individually and analyzed with different control voltages from 10 to 18 V. The highest flow ratio of MVC-AVC/AVC-MVC was noted when the T-LVAD worked on 14 V. By using analysis methodology of the flow ratio of a cardiac cycle, the optimal physiologically effective control of the T-LVAD might be achieved.     

Gender and age differences among youth, in utilization of mental health services in the year preceding suicide in taiwan

The primary objective of this study was to explore gender and age differences in the use of medical services during the year preceding suicide. Data were obtained from the mortality dataset of Department of Health and National Health Insurance Database. Included in the sample were 862 persons aged 12-24?years who committed suicide in Taiwan between 2001 and 2004. We compared the records of medical service utilization of adolescents (ages 12-18?years) with young adults (ages 19-24?years). Persons in both age groups contacted general practitioners more often than other types of medical providers in the year preceding suicide, with the exception of the month before suicide. Females made greater use of medical services than males in both age groups. Suicide prevention strategies should increase the emphasis in training non-psychiatric medical practitioners to identify and treat young persons at suicide risk.     

Absence of ongoing activity in fibres arising from proximal nerve ends regenerating into mesothelial chambers

Morphological studies have indicated that proximal nerve ends of transected rat sciatic nerves regenerating into preformed mesothelial chambers show a different organization as compared to neuromas developed in contact with a muscle fascia. We have studied the physiological properties of nerve fibres arising from these types of preparations with reference to ongoing activity, response to mechanical stimulation and noradrenaline sensitivity. The study included also fibres arising from ligated and encapsulated neuromas. Fibres with ongoing activity arising from the neuroma could be found from neuromas in contact with a muscle fascia and also from ligated and encapsulated neuromas. This ongoing activity was enhanced by mechanical stimulation and i.v. infusion of noradrenaline. In contrast, fibres arising from proximal nerve ends in mesothelial chambers did not show ongoing activity. These silent fibres responded dynamically to light mechanical stimulation. Noradrenaline did not induce ongoing activity in these fibres.     

Depressive Symptoms as a Predictor of Sexual Function during Pregnancy

IntroductionBiopsychological and sociocultural factors have been reported to be associated with sexual function in pregnancy. To date, very few studies have focused on the relationship between sexual function and depression during pregnancy.AimTo determine whether depressive symptoms predict overall sexual function, desire, arousal, lubrication, orgasm, satisfaction, and pain during pregnancy by using the Female Sexual Function Index (FSFI).MethodsPregnant women undergoing prenatal examinations were randomly selected for this cross‐sectional investigation. The study included 555 pregnant women who completed the Taiwanese versions of the Center for Epidemiologic Studies Depression Scale (CES‐D), FSFI, and a demographic questionnaire during pregnancy.Main Outcome MeasuresCES‐D scores for depressive symptoms, scores for overall sexual function on the FSFI, and the FSFI domains: desire, arousal, lubrication, orgasm, satisfaction, and pain.ResultsAfter adjusting for demographic factors, CES‐D scores during the first trimester negatively predicted overall sexual function (P = 0.0004), arousal (P = 0.0104), lubrication (P = 0.0016), orgasm (P = 0.0022), and pain (P < 0.0001). Moreover, CES‐D scores during the third trimester negatively predicted sexual desire (P = 0.0005) and satisfaction (P < 0.0001). Furthermore, gestational age negatively predicted overall sexual function, arousal, lubrication, orgasm, and pain (all P < 0.0001). Parity was a positive predictor of overall sexual function, arousal, lubrication, and orgasm (all P < 0.0005). Medical conditions were positive predictors of sexual desire (P = 0.0023).ConclusionsThe present study revealed that depressive symptom scores during early and late pregnancy were significant negative predictors of sexual function during pregnancy. Chang S‐R, Ho H‐N, Chen K‐H, Shyu M‐K, Huang L‐H, and Lin W‐A. Depressive symptoms as a predictor of sexual function during pregnancy. J Sex Med **;**:**–**.     

Second trimester maternal serum hCG level in an Asian population: normal reference values by ultrasound dating

OBJECTIVE: To establish normative data of maternal serum chorionic gonadotropin (hCG) during the second trimester in an Asian population. METHODS: We measured the maternal serum hCG levels in 17,955 normal singleton pregnancies between 15 and 21 weeks of gestation. The gestation age was estimated by measurement of fetal biparietal distance (BPD) in all cases. Median values of hCG at various gestational weeks were calculated and the values of hCG were converted to multiple of median (MoM). The incidences of low MoM value and high MoM value were also calculated. RESULTS: The mean and median values of hCG were 57,153 mIU/ml and 50,120 mIU/ml, respectively, at 15 weeks of gestation and then decreased to 30,898 mIU/ml and 26,226 mIU/ml, respectively, at 21 weeks. We found 8.6% and 9.4% of normal singleton pregnancies have hCG MoM values >2.0 MoM and <0.5 MoM, respectively. CONCLUSIONS: Our report provides a normal reference data of second trimester maternal hCG levels by ultrasound dating in an Asian population.     

Human mesenchymal stem cells improve myocardial performance in a splenectomized rat model of chronic myocardial infarction.

BACKGROUND/PURPOSE: Cellular therapy has been applied to animal studies and clinical trials for acute or subacute myocardial infarction. Little is known about the effect of cell therapy on chronic myocardial infarction. The goal of this study was to investigate myocardial performance after human bone marrow-derived mesenchymal stem cell (hMSCs) transplantation in rats with chronic myocardial infarction. METHODS: The hMSCs were obtained from adult human bone marrow and expanded in vitro. The purity and characteristics of hMSCs were identified by flow cytometry and immunophenotyping. Splenectomy in male rats was performed to prevent immune reaction. One week after splenectomy, ligation of the left anterior descending coronary artery was performed to induce myocardial infarction. Four weeks after ligation of the coronary artery, culture-expanded hMSCs were injected intramyocardially at the left anterior free wall. Left ventricular function measured by echocardiography, infarct size and immunohistochemical stain were performed to evaluate the effect of the therapy. RESULTS: The engrafted hMSCs were positive for the cardiac marker troponin T. Infarct size (35.4 +/- 3.4% vs. 53.3 +/- 3.0%, p < 0.001) and fibrotic area (2.6 +/- 0.1% vs. 5.9 +/- 0.2%, p < 0.001) were significantly smaller in the hMSC-treated group than in the control group at 28 days after therapy. hMSC transplantation resulted in smaller left ventricular end-diastolic dimension (6.5 +/- 0.1 mm vs. 7.9 +/- 0.7 mm, p < 0.001) and better left ventricular ejection fraction (88.7 +/- 1.2% vs. 65.8 +/- 2.5%, p < 0.001) than in the control group. Capillary density was markedly increased after hMSC transplantation compared with the control group. CONCLUSION: This study demonstrates that intramyocardial transplantation of hMSCs improves cardiac function after chronic myocardial infarction through enhancement of angiogenesis and myogenesis in the ischemic myocardium. Transplantation of hMSCs for myocardial regeneration may become the future therapy for chronic myocardial infarction.     

Sympathetic and noradrenaline effects on C-fibre transmission: single-unit analysis

Single afferent unmyelinated fibres were dissected from the otherwise intact sural nerve in anesthetized rabbits. The sympathetic trunk could be stimulated via electrodes implanted through the abdomen. The response in single C fibres was elicited by electrical stimulation in the cutaneous innervation area of the fibre. Sympathetic stimulation (8 Hz, 1 ms pulses, 5 mA for 60 s) increased the latency in all tested C fibres (2.0% +/- 0.8%, mean +/- SD, n = 17). In 48% of the units the amplitude of the action potential decreased (26.4% +/- 12.3%) during sympathetic stimulation. Infusion of noradrenaline (5 micrograms min-1) increased (7.7% +/- 4.1%) the latency in all units and increased (36.9% +/- 29.8%) the amplitude of 25% of the units. The effects of sympathetic stimulation and noradrenaline infusion were blocked by pre-treatment with phentolamine (3 mg kg-1 i.v.). The results suggest that catecholamines change the membrane properties of unmyelinated fibres.     

Older people with hip fracture: depression in the postoperative first year

Title. Older people with hip fracture: depression in the postoperative first year. Aim. This paper is a report of a study conducted to describe changes in risk of depressive symptoms and their predictors for older people with hip fracture during the first year following hospital discharge. Background. The prevalence of depression in older people with hip fracture has been reported as 9–47%. However, the longitudinal changes in prevalence rate following hip fracture have not been well‐studied, particularly in Asian countries. Methods. The study was conducted in Taiwan in 2001–2003. A sample of 147 older people with hip fracture was assessed for depressive symptoms before discharge, and at 1, 3, 6 and 12 months after discharge using the Chinese version of the Geriatric Depression Scale. Longitudinal data were analysed by the generalized estimating equation approach. Findings. The majority of participants were at risk for depressive symptoms before discharge (n = 147, 57·8%) and 35·6% (n = 118) 12 months after discharge. These numbers decreased statistically significantly from before discharge to the 1st month after discharge (57·8% vs. 42·6%, P = 0·008), and from the 1st to the 6th month (42·6% vs. 31·3%, P = 0·03), and then remained stable until the 12th month after discharge. Lower emotional‐social support predicted persistent depressive symptoms after discharge (P < 0·01). Conclusion. Timely psychological interventions are suggested within the first 6 months after discharge, especially the first 3 months. Healthcare professionals need to pay attention to older patients with hip fracture who are female, with poorer prefracture functioning and particularly those with lower emotional‐social support.