Autonomic dysfunction and treatment strategies in intracerebral hemorrhage.

AIMS: Autonomic dysfunction with central autonomic network (CAN) damage occurs frequently after intracerebral hemorrhage (ICH) and contributes to a series of adverse outcomes. This review aims to provide insight and convenience for future clinical practice and research on autonomic dysfunction in ICH patients. DISCUSSION: We summarize the autonomic dysfunction in ICH from the aspects of potential mechanisms, clinical significance, assessment, and treatment strategies. The CAN structures mainly include insular cortex, anterior cingulate cortex, amygdala, hypothalamus, nucleus of the solitary tract, ventrolateral medulla, dorsal motor nucleus of the vagus, nucleus ambiguus, parabrachial nucleus, and periaqueductal gray. Autonomic dysfunction after ICH is closely associated with neurological functional outcomes, cardiac complications, blood pressure fluctuation, immunosuppression and infection, thermoregulatory dysfunction, hyperglycemia, digestive dysfunction, and urogenital disturbances. Heart rate variability, baroreflex sensitivity, skin sympathetic nerve activity, sympathetic skin response, and plasma catecholamine concentration can be used to assess the autonomic functional activities after ICH. Risk stratification of patients according to autonomic functional activities, and development of intervention approaches based on the restoration of sympathetic-parasympathetic balance, would potentially improve clinical outcomes in ICH patients. CONCLUSION: The review systematically summarizes the evidence of autonomic dysfunction and its association with clinical outcomes in ICH patients, proposing that targeting autonomic dysfunction could be potentially investigated to improve the clinical outcomes.

Application of five risk stratification tools for syncope in older adults.

OBJECTIVE: Treatment of syncope in older adults places a burden on healthcare systems. We used five risk stratification tools to predict short-term adverse outcomes in older patients with syncope. METHODS: This was a retrospective analysis of patients with syncope (age ≥60 years) in the emergency department of an urban academic hospital. The data were evaluated using the Risk Stratification of Syncope in the Emergency Department (ROSE), San Francisco Syncope Rule (SFSR), FAINT, Canadian Syncope Risk Score (CSRS), and Boston Syncope Criteria (BSC) tools. Sensitivity, specificity, accuracy, positive and negative predictive value (NPV), and positive and negative likelihood ratios of each tool were calculated and compared for adverse events within 1 month. RESULTS: In total, 221 patients (average age 75.6 years) were analyzed. Fifty-nine patients (26.7%) had experienced an adverse event within 1 month. For the ROSE, SFSR, FAINT, CSRS and BSC tools, sensitivities were 81.3%, 76.3%, 93.2%, 71.2%, and 94.9%, specificities were 88.3%, 87.7%, 56.8%, 71.6%, and 67.3%, and NPVs were 92.9%, 91.0%, 95.8%, 87.2%, and 97.3%, respectively. CONCLUSION: The five assessed tools could be useful for physicians in screening older patients with syncope for the risk of short-term adverse events, according to the patient's actual situation.

Extraction, derivatization, and determination of metabolome in human macrophages.

A GC/TOF-MS was applied to the determination of metabolites in human macrophages. The extraction conditions and quenching conditions were investigated and optimized. The results indicated that 0.9% w/v sodium chloride at 4°C was the most favorable condition to quench macrophage, 1 mL 50% ACN for 2 min in ice bath was the optimal condition to extract 5 × 10(6) cells. Two hundred six peaks could be detectable with peak area over 50 using this method. Among these peaks, 45 peaks with the similarity over 700 were identified using standard compounds for endogenous metabolites. Thirty-seven out of 45 metabolites could be quantified directly by this method. Twenty metabolites were selected randomly, and 15 amino acids were used for method validation. The correlation coefficients (r) ranging from 0.9902 to 0.9977 were obtained for 15 amino acids in the range of 2.35-150.20 µg/mL. The intraday and interday precisions were lower than 19.90% for the randomly selected 20 endogenous metabolites. Using this development method and multivariate statistical technique, several potential biomarkers were found from human macrophages infected by different Mycobacterium tuberculosis (M. tuberculosis) strains. The results suggest that the method could be applied to the investigation of the pathogenicity of tuberculosis.

Haemodynamic adaptation during sudden gravity transitions.

Haemodynamic responses during parabolic flight were studied. The hypothesis that haemodynamic changes may be counteracted by a transient vagal reflex during acute gravity transitions was tested. ECG, arterial pressure and respiration were recorded continuously in seven male subjects during parabolic flight. Beat-to-beat haemodynamic parameters were estimated. In the supine position no significant differences were shown among the different gravity phases. In the upright position, significant within-group differences were observed across gravity phases for all parameters. Postural differences in haemodynamic data disappeared during the microgravity phase and were enlarged during hypergravity phases. Detailed temporal analysis of cardiac time series in standing subjects confirmed the hypothesized biphasic response of initial parasympathetic modulation: a sharp increase of RRI within 3-5 s followed by a 10% decrease in the remaining period of microgravity (p < 0.001); a sharp increase in SAP within 2-4 s followed by a slow decrease of 25%. Significant within-group differences were observed in the standing position for mean RRI (836 ± 170 ms, p = 0.003), DAP (66 ± 8 mmHg, p < 0.001), MAP (139 ± 12 mmHg, p = 0.001), RRI HF amplitude (17.6 ± 7.5 ms, p < 0.001), SV (146 ± 5%, p < 0.001) and SVR (73 ± 10%, p = 0.020). In standing subjects, the initial baroreflex-mediated vagal heart rate response is limited to a transition period at early microgravity lasting about 3-5 s, followed by a gradual heart rate recovery during the remaining 15-17 s due to a parasympathetic withdrawal. The resultant increase in cardiac output induces a baroreflex-mediated systemic vasodilatation, which may be the driving force for a decreased arterial pressure in weightlessness.

Serum biochemical indicators of hepatobiliary function in dogs following prolonged anaesthesia with sevoflurane or isoflurane.

OBJECTIVE: To investigate the changes in serum enzymes considered as biochemical indicators of hepatobiliary function in dogs following 5 hours of anaesthesia with isoflurane (ISO) or sevoflurane (SEVO). STUDY DESIGN: Experimental randomized crossover study, with intervals of at least 15 days between successive treatments. ANIMALS: Eight healthy adult mongrel dogs, four male, four female, weight 13.6-21.6 kg. METHODS: Treatments consisted of anaesthesia with ISO or SEVO at 1 or 1.5 minimum alveolar concentration (MAC) delivered in oxygen. MAC was taken as 1.39% for ISO and 2.36% for SEVO. Anaesthesia was induced by mask then, after endotracheal intubation, maintained according to the treatment protocol using a small animal circle system. Cardiopulmonary monitoring was carried out. Venous blood samples, obtained by needle puncture, were taken at 24 hours and 2, 7 and 14 days post anaesthesia. Serum concentrations of total protein, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase, (LDH), alkaline phosphatase (ALP), gamma-glutamyltransferese and total bilirubin were measured. Changes with time and with treatment were compared by Friedman analysis, Wilcoxon Signed test and Kruskal-Wallis test as relevant. p- value < 0.05 was considered significant. RESULTS: Compared to base-line values, at 24 hours post-anaesthesia there were significant increases in AST, ALT, ALP and LDH following one or more of the treatments, but by 2 days residual changes were not significant. At 24 hours, AST for treatment 1.5 MAC ISO was higher than 1 MAC ISO (p < 0.002), and LDH higher for 1.5 MAC SEVO than 1 MAC SEVO. CONCLUSION AND CLINICAL RELEVANCE: Both ISO and SEVO, at concentrations used for clinical anaesthesia, produce transient moderate effects on some hepatobiliary enzyme concentrations in dogs.

Exploring the Impact and Prevention of Epidemics from a New Perspective: COVID-19 Transmission through Express Boxes.

The number of express boxes worldwide exceeded 170 billion in 2021, and, from several regions in China, tested positive. Therefore, it is important to study the transmission of viruses through express boxes. In this paper, we establish a model of express box virus transmission based on comprehensive consideration of environmental factors, such as temperature, disinfection, humidity, virus release intensity, and volume of vehicle, to study the transmission of express box virus, and explore the spatial and geographic spread variation of express box viruses in China. Several important findings emerged from the study, including: (1) Disinfection can prolong the spread of viruses in the express box for ≥21 h; (2) For every 1 °C rise in temperature, the infected time can be prolonged by ≥1.2 h, and for every 10% rise in relative humidity, the virus transmission time can be prolonged by ≥1.32 h; (3) In an environment suitable for virus transmission, when loaded with 1000, 2000, 4000 express boxes, areas where the express delivery time exceeds 22.56, 18, 14.64 h will face the risk of all the boxes in the carriage being infected. These findings could help public health departments prevent the risk of virus transmission from express boxes.

A Flexible Ultrasound Array for Local Pulse Wave Velocity Monitoring.

Pulse wave velocity (PWV) measured at a specific artery location is called local PWV, which provides the elastic characteristics of arteries and indicates the degree of arterial stiffness. However, the large and cumbersome ultrasound probes require an appropriate sensor position and pressure maintenance, introducing usability constraints. In this paper, we developed a light (0.5 g) and thin (400 µm) flexible ultrasound array by encapsulating 1-3 composite piezoelectric transducers with a silicone elastomer. It can capture the distension waveforms of four arterial positions with a spacing of 10 mm and calculate the local PWV by multi-point fitting. This is illustrated by in vivo experiments, where the local PWV value of five normal subjects ranged from 3.07 to 4.82 m/s, in agreement with earlier studies. The beat-to-beat coefficient of variation (CV) is 12.0% ± 3.5%, showing high reliability. High reproducibility is shown by the results of two groups of independent measurements of three subjects (the error between the mean values is less than 0.3 m/s). These properties of the developed flexible ultrasound array enable the bandage-like application of local PWV monitoring to skin surfaces.

Running vs. resistance exercise to counteract deconditioning induced by 90-day head-down bedrest.

Spaceflight is associated with enhanced inactivity, resulting in muscular and cardiovascular deconditioning. Although physical exercise is commonly used as a countermeasure, separate applications of running and resistive exercise modalities have never been directly compared during long-term bedrest. This study aimed to compare the effectiveness of two exercise countermeasure programs, running and resistance training, applied separately, for counteracting cardiovascular deconditioning induced by 90-day head-down bedrest (HDBR). Maximal oxygen uptake ( V ˙ O2max), orthostatic tolerance, continuous ECG and blood pressure (BP), body composition, and leg circumferences were measured in the control group (CON: n = 8), running exercise group (RUN: n = 7), and resistive exercise group (RES: n = 7). After HDBR, the decrease in V ˙ O2max was prevented by RUN countermeasure and limited by RES countermeasure (-26% in CON p < 0.05, -15% in RES p < 0.05, and -4% in RUN ns). Subjects demonstrated surprisingly modest orthostatic tolerance decrease for different groups, including controls. Lean mass loss was limited by RES and RUN protocols (-10% in CON vs. -5% to 6% in RES and RUN). Both countermeasures prevented the loss in thigh circumference (-7% in CON p < 0.05, -2% in RES ns, and -0.6% in RUN ns) and limited loss in calf circumference (-10% in CON vs. -7% in RES vs. -5% in RUN). Day-night variations in systolic BP were preserved during HDBR. Decrease in V ˙ O2max positively correlated with decrease in thigh (r = 0.54 and p = 0.009) and calf (r = 0.52 and p = 0.012) circumferences. During this 90-day strict HDBR, running exercise successfully preserved V ˙ O2max, and resistance exercise limited its decline. Both countermeasures limited loss in global lean mass and leg circumferences. The V ˙ O2max reduction seems to be conditioned more by muscular than by cardiovascular parameters.

Using appendicitis scores in the pediatric ED.

STUDY OBJECTIVE: The aims of the study were to prospectively evaluate the Alvarado and Samuel (pediatric appendicitis score [PAS]) appendicitis scoring systems in children and determine performance based on sex. METHODS: Children with abdominal pain concerning for appendicitis were recruited. Nine parameters evaluated by the scores were documented before imaging/surgery consultation. Test characteristics were calculated on all patients and by sex. RESULTS: Two hundred eighty-seven patients enrolled; median age was 9.8 years; and 155 (54%) were diagnosed with pathologic examination-confirmed appendicitis. Patients with appendicitis had mean PAS of 7.6, and those without had mean of 5.6 (P < .001). Patients with appendicitis had a mean Alvarado of 7.2, and those without had a mean of 5.2 (P < .001). In appendicitis patients, PAS cutoff of 6 or greater would give 137 correct diagnoses; sensitivity, 88%; specificity, 50%; and positive predictive value (PPV), 67%. An Alvarado cutoff of 7 or greater would give 118 correct diagnoses; sensitivity, 76%; specificity, 72%; and PPV, 76%. Both performed better in males than females. CONCLUSION: Regardless of sex, neither PAS nor Alvarado has adequate predictive values for sole use to diagnose appendicitis.

The efficacy of mechanical vibration analgesia for relief of heel stick pain in neonates: a novel approach.

BACKGROUND: Hospitalized infants are often exposed to many painful procedures as a result of their illness or disease process. Untreated or poorly treated pain can have deleterious effects on normal nociceptive pain development as well as future development of pain pathways. Mechanical vibration has been found to be efficacious in adult and pediatric populations for the relief of mild-to-moderate acute and chronic pain. However, little is known about the efficacy of this intervention in the neonatal population. AIM: The purpose of this study was to test the hypothesis that mechanical vibration would be efficacious in the relief of pain associated with heel sticks in neonates. Heel sticks are one of the most common painful procedures during neonatal hospitalization. STUDY DESIGN: A random-sequencing crossover design was used with infants acting as their own controls. SUBJECTS: Newborn infants of 35 weeks' gestation or greater (N = 20) met the inclusion criteria for the study. OUTCOME MEASURES: Pain during heel stick was measured with the Neonatal Infant Pain Scale. The Neonatal Infant Pain Scale is a nonintrusive tool with extensive evidence of its reliability and validity in the neonatal population, when used by trained observers. RESULTS: Mechanical vibration produced an analgesic effect for infants who had previously experienced painful heel sticks that approached statistical significance. CONCLUSIONS: The apparent limitations of mechanical vibration as analgesia may be due to the concurrent use of sucrose and pacifier, the effects of order (ie, habituation), or type II error. Because vibration produced the predicted positive effect in some circumstances, further investigation in larger samples within a randomized clinical trial is warranted.

Motivational intervention to reduce rapid subsequent births to adolescent mothers: a community-based randomized trial.

PURPOSE: One-quarter of adolescent mothers bear another child within 2 years, compounding their risk of poorer medical, educational, economic, and parenting outcomes. Most efforts to prevent rapid subsequent birth to teenagers have been unsuccessful but have seldom addressed motivational processes. METHODS: We conducted a randomized trial to determine the effectiveness of a computer-assisted motivational intervention (CAMI) in preventing rapid subsequent birth to adolescent mothers. Pregnant teenagers (N = 235), aged 18 years and older who were at more than 24 weeks' gestation, were recruited from urban prenatal clinics serving low-income, predominantly African American communities. After completing baseline assessments, they were randomly assigned to 3 groups: (1) those in CAMI plus enhanced home visit (n = 80) received a multi-component home-based intervention (CAMI+); (2) those in CAMI-only (n = 87) received a single component home-based intervention; (3) and those in usual-care control (n = 68) received standard usual care. Teens in both intervention groups received CAMI sessions at quarterly intervals until 2 years' postpartum. Those in the CAMI+ group also received monthly home visits with parenting education and support. CAMI algorithms, based on the transtheoretical model, assessed sexual relationships and contraception-use intentions and behaviors, and readiness to engage in pregnancy prevention. Trained interventionists used CAMI risk summaries to guide motivational interviewing. Repeat birth by 24 months' postpartum was measured with birth certificates. RESULTS: Intent-to-treat analysis indicated that the CAMI+ group compared with the usual-care control group exhibited a trend toward lower birth rates (13.8% vs 25.0%; P = .08), whereas the CAMI-only group did not (17.2% vs 25.0%; P = .32). Controlling for baseline group differences, the hazard ratio (HR) for repeat birth was significantly lower for the CAMI+ group than it was with the usual-care group (HR = 0.45; 95% CI, 0.21-0.98). We developed complier average causal effects models to produce unbiased estimates of intervention effects accounting for variable participation. Completing 2 or more CAMI sessions significantly reduced the risk of repeat birth in both groups: CAMI+ (HR = 0.40; 95% CI, 0.16-0.98) and CAMI-only (HR = 0.19; 95% CI, 0.05-0.69). CONCLUSIONS: Receipt of 2 or more CAMI sessions, either alone or within a multicomponent home-based intervention, reduced the risk of rapid subsequent birth to adolescent mothers.

Bypass of local primary care in rural counties: effect of patient and community characteristics.

PURPOSE: This national study sought information from rural patients (1) to assess the prevalence of bypass, a pattern of seeking health care outside the local community; (2) to examine the impact of locally available primary care physicians (PCPs) and hospital size on the odds of bypass; and (3) to identify patient demographic and geographic factors associated with bypass. This study also ascertained the reasons patients give for bypass and their suggestions for how hospitals can retain patients locally. METHODS: We analyzed data from a 2005 telephone survey of 1,264 adults, aged 18 years or older, who lived within 20 miles of 25 randomly selected Critical Access Hospitals and were linked with a Health Professional Shortage Area and 2004 census data. Respondents were asked about demographic characteristics, travel time and distance to local hospitals, and insurance status, as well as for suggestions of what local hospitals could do to retain patients. RESULTS: Overall, 32% of respondents bypassed local primary care; the rate ranged from 9% to 66% across the Critical Access Hospital service areas. Factors associated with bypass included age, education, marital status, satisfaction with the local hospital, admission to a hospital in the past 12 months, hospital size, and local density of PCPs. Compared with residents in areas with a higher density of PCPs (=3,500 residents per PCP), residents in areas with a low density (>4,500 residents per PCP) were more likely to bypass local care (odds ratio, 1.58; 95% confidence interval, 1.02-2.46). Lack of specialty care and limited services were most frequently mentioned as reasons why patients bypassed local hospitals. CONCLUSIONS: The sizable variation in bypass rates among this sample of Critical Access Hospital service areas suggests that strategies to reduce bypass behavior should be directed at the local community or facility level. Changing rural residents' perception of their local care, helping them gain a better understanding of the function of primary care, and increasing the number of PCPs might help hospitals retain patients and rural communities stay healthy.

Effect of partner relationship on motivation to use condoms among adolescent mothers.

PURPOSE: Adolescent mothers have high rates of repeat pregnancy and sexually transmitted infections (STIs). We sought to identify factors associated with their consistent condom use. METHODS: Data for 107 urban adolescent mothers enrolled in a longitudinal computer-assisted motivational interviewing (CAMI) intervention were analyzed. The intervention aimed to motivate and instill confidence in using condoms consistently. DATA SOURCES: 1) structured interviews during the third trimester of pregnancy (baseline), 2) CAMI responses at 9-12 months postpartum. Outcomes were dichotomized as: consistent condom users and inconsistent condom users. RESULTS: At baseline, mean age was 17 (1.1 SD) years, 96% African American, and 26% reported always using condoms. At 9-12 months postpartum, 33 (31%) used condoms consistently. Consistent condom users were less likely to report having sex with their baby's father (61% vs. 81%; p = 0.05). Adolescent mothers who used condoms consistently experienced greater self-efficacy in the prevention of STIs and recognized the importance of preventing STIs with a new boyfriend (p = 0.006). Consistent condom users held the opinion that it was more important to use condoms with a new boyfriend than with their baby's father regardless whether their main partner was the father of their baby or a new boyfriend. CONCLUSIONS: Level of motivation, belief in the importance of condom use and self-efficacy to use condoms with a new boyfriend regardless of actual sexual partner relationship were the strongest predictors of consistent condom use among adolescent mothers. Future interventions aimed at improving condom use should focus on motivation and to different views held by teens regarding their partner-specific condom use.

Factors predicting perceived improved health after emergency room visits.

AIM: This study examines the key factors contributing to perceived improved health after emergency room (ER) visits. BACKGROUND: Perceived health is a subjective measure of health status. It is an important and useful concept in nursing and assessment of health services because it reflects the clients' own assessment of his/her health, which may have led to their subsequent health-seeking behaviour. METHODS: Secondary analysis of a main study which aimed at examining the effects of nurse follow-up on ER revisits using randomized-controlled trial. In this study, binary logistic regressions were conducted to identify factors associated with the dependent variable, perceived improved health 30 days after the index ER visit. Data were collected from 795 subjects and the sources of data were from medical records and telephone interviews. RESULTS: Gender, income, usual practice in managing minor illness, what to do other than attending the ER, nurse follow-up, general self-rated health, triage, considered other doctors on the day of index ER visit, times of attending general outpatient clinic and times of attending general practitioner were found to be significantly associated with perceived improved health 30 days after the index ER visit. CONCLUSION: Many of the variables identified in this study that predicted perceived improved health concurred with previous findings. What is of interest is that nurse follow-up but not multiple medical consultations helped enhance perceived improved health. We speculate that there was no continuity of care in the multiple medical consultations. Where as in the nurse follow-up, the nurse was able to follow through the care of individuals, monitor their progress and make appropriate referrals. This study shows that the nurse is an appropriate person to mediate the health needs of individuals and the healthcare system and to enhance health maintenance for individuals in the community without excessively using medical services. RELEVANCE TO CLINICAL PRACTICE: The nurses providing care during the transitional phase should not only include the traditional clinical or hospital system variables, but should also take into account the general health perception of patients, because these are the predictors of health services utilization and morbidity.

Home visiting for adolescent mothers: effects on parenting, maternal life course, and primary care linkage.

PURPOSE: Adolescent mothers are at risk for rapidly becoming pregnant again and for depression, school dropout, and poor parenting. We evaluated the impact of a community-based home-visiting program on these outcomes and on linking the adolescents with primary care. METHODS: Pregnant adolescents aged 12 to 18 years, predominantly with low incomes and of African American race, were recruited from urban prenatal care sites and randomly assigned to home visiting or usual care. Trained home visitors, recruited from local communities, were paired with each adolescent and provided services through the child's second birthday. They delivered a parenting curriculum, encouraged contraceptive use, connected the teen with primary care, and promoted school continuation. Research assistants collected data via structured interviews at baseline and at 1 and 2 years of follow-up using validated instruments to measure parenting (Adult-Adolescent Parenting Inventory) and depression (Center for Epidemiologic Studies Depression). School status and repeat pregnancy were self-reported. We measured program impact over time with intention-to-treat analyses using generalized estimating equations (GEE). RESULTS: Of 122 eligible pregnant adolescents, 84 consented, completed baseline assessments, and were randomized to a home-visited group (n = 44) or a control group (n = 40). Eighty-three percent completed year 1 or year 2 follow-up assessments, or both. With GEE, controlling for baseline differences, follow-up parenting scores for home-visited teens were 5.5 points higher than those for control teens (95% confidence interval, 0.5-10.4 points; P = .03) and their adjusted odds of school continuation were 3.5 times greater (95% confidence interval, 1.1-11.8; P <.05). The program did not have any impact on repeat pregnancy, depression, or linkage with primary care. CONCLUSIONS: This community-based home-visiting program improved adolescent mothers' parenting attitudes and school continuation, but it did not reduce their odds of repeat pregnancy or depression or achieve coordination with primary care. Coordinated care may require explicit mechanisms to promote communication between the community program and primary care.

Patient bypass behavior and critical access hospitals: implications for patient retention.

PURPOSE: To assess the extent of bypass for inpatient care among patients living in Critical Access Hospital (CAH) service areas, and to determine factors associated with bypass, the reasons for bypass, and what CAHs can do to retain patients locally. METHODS: Six hundred and forty-seven subjects, aged 18 years and older, who had been admitted to a hospital for inpatient care in the past 12 months and lived within 15-20 miles of 25 randomly selected CAHs were surveyed by phone during the period from early February through late July 2005. Survey questions included demographic characteristics, general health status, travel time/distance to health care, questions on satisfaction with local health services, bypass behavior, and solicited suggestions on how local hospitals could retain patients locally. FINDINGS: About 60% of surveyed patients bypassed their local CAHs for inpatient care including 16% who were referred to another facility by the local CAH/health care providers and would use the local hospital if needed services were available. Bypass rates ranged from 16% to 70% across the sampled CAHs. Factors associated with bypass included age, income, satisfaction with the local hospital, and traveling distance/time. Lack of specialty care, limited services, and the quality/reputation of local services/doctors were most frequently mentioned as reasons why patients bypass local CAHs. CONCLUSIONS: The bypass rate for sampled CAHs is considerably higher than the 20%-50% bypass rates documented in the literature for all hospitals in general using discharge/administrative data. The sizeable variation in bypass rates across CAHs suggests that the appropriate response/fix should come from the facility/community levels.

Health professional shortage and health status and health care access.

Although areas designated as Health Professional Shortage Areas (HPSAs) have fewer primary care physicians than non-HPSAs, few studies have tested whether HPSA designation is related to health status and medical service access. This study examined whether residents living in HPSAs were more likely to report worse health status and to be more likely to have difficulty in getting access medical services than residents living in non-HPSAs, with survey data of 10,940 adult West Virginians. Multiple regression results indicate that HPSA is associated with worse general health status and poor physical health, and less access to medical services (measured by had usual place for medical care, experienced not getting needed health care and had outpatient care) but not to inpatient care. These findings indicate that the current HPSA designation system does capture the significant differences between residents of HPSAs and residents of non-HPSAs in health status and medical services access.

Decreased left atrial strain parameters are correlated with prolonged total atrial conduction time in lone atrial fibrillation.

To investigate left atrium (LA) strain properties of patients with lone atrial fibrillation (LAF) and to assess relationships between LA strain parameters and total atrial conduction time measured with tissue Doppler imaging (PA-TDI). The study population consisted of 53 patients with LAF. The control group was comprised of 50 normal volunteers. Conventional echocardiography indices were measured. Mitral annular velocities and PA-TDI were assessed with TDI. Two-dimensional speckle-tracking echocardiography (2D-STE) was used to assess LA segmental strain and strain rate. Compared with the control group, PA-TDI was significantly prolonged and LA myocardial Ss, SRs, Sa, and SRa were significantly decreased in the LAF group (all P < 0.001). In the control group, LA myocardial Ss (γ = -0.486, P < 0.01), SRs (γ = -0.436, P < 0.01), and Sa (γ = -0.360, P < 0.05) were correlated negatively with PA-TDI. LA myocardial SRa (γ = 0.377, P < 0.01) was correlated positively with PA-TDI. In the LAF group, LA myocardial Ss (γ = -0.429, P < 0.01), SRs (γ = -0.468, P < 0.01), and Sa (γ = -0.380, P < 0.05) were also correlated negatively, and SRa (γ = 0.390, P < 0.01) was correlated positively, with PA-TDI. Multivariate logistic regression identified PA-TDI as the only predictor of AF onset (OR 1.39; 95 % CI 1.02-1.54; P < 0.01). LA strain parameters were decreased and PA-TDI was prolonged in patients with LAF. Structural remodeling of the LA, assessed by 2D-STE, was correlated with electrical remodeling, determined by PA-TDI. Prolonged PA-TDI was independently associated with AF onset.

Orthostatic Intolerance Is Independent of the Degree of Autonomic Cardiovascular Adaptation after 60 Days of Head-Down Bed Rest.

Spaceflight and head-down bed rest (HDBR) can induce the orthostatic intolerance (OI); the mechanisms remain to be clarified. The aim of this study was to determine whether or not OI after HDBR relates to the degree of autonomic cardiovascular adaptation. Fourteen volunteers were enrolled for 60 days of HDBR. A head-up tilt test (HUTT) was performed before and after HDBR. Our data revealed that, in all nonfainters, there was a progressive increase in heart rate over the course of HDBR, which remained higher until 12 days of recovery. The mean arterial pressure gradually increased until day 56 of HDBR and returned to baseline after 12 days of recovery. Respiratory sinus arrhythmia and baroreflex sensitivity decreased during HDBR and remained suppressed until 12 days of recovery. Low-frequency power of systolic arterial pressure increased during HDBR and remained elevated during recovery. Three subjects fainted during the HUTT after HDBR, in which systemic vascular resistance did not increase and remained lower until syncope. None of the circulatory patterns significantly differed between the fainters and the nonfainters at any time point. In conclusion, our data indicate that the impaired orthostatic tolerance after HDBR could not be distinguished by estimation of normal hemodynamic and/or neurocardiac data.

Is autonomic modulation different between European and Chinese astronauts?

PURPOSE: The objective was to investigate autonomic control in groups of European and Chinese astronauts and to identify similarities and differences. METHODS: Beat-to-beat heart rate and finger blood pressure, brachial blood pressure, and respiratory frequency were measured from 10 astronauts (five European taking part in three different space missions and five Chinese astronauts taking part in two different space missions). Data recording was performed in the supine and standing positions at least 10 days before launch, and 1, 3, and 10 days after return. Cross-correlation analysis of heart rate and systolic pressure was used to assess cardiac baroreflex modulation. A fixed breathing protocol was performed to measure respiratory sinus arrhythmia and low-frequency power of systolic blood pressure variability. RESULTS: Although baseline cardiovascular parameters before spaceflight were similar in all astronauts in the supine position, a significant increase in sympathetic activity and a decrease in vagal modulation occurred in the European astronauts when standing; spaceflight resulted in a remarkable vagal decrease in European astronauts only. Similar baseline supine and standing values for heart rate, mean arterial pressure, and respiratory frequency were shown in both groups. Standing autonomic control was based on a balance of higher vagal and sympathetic modulation in European astronauts. CONCLUSION: Post-spaceflight orthostatic tachycardia was observed in all European astronauts, whereas post-spaceflight orthostatic tachycardia was significantly reduced in Chinese astronauts. The basis for orthostatic intolerance is not apparent; however, many possibilities can be considered and need to be further investigated, such as genetic diversities between races, astronaut selection, training, and nutrition, etc.