Search

Immigrants in the U.S. often experience better health than the native-born, and many explanations for this phenomenon center around the positive health behaviors that immigrants bring from their home cultures. Immigrants from the former Soviet Union may be an exception; because they come from societies where unhealthy lifestyles and high mortality are common, they are often expected to experience worse health than the native population. Using data from the Integrated Health Interview Series, I compare FSU immigrants with U.S.-born, non-Hispanic whites on several health measures. FSU immigrants are twice as likely as native whites to report fair or poor health, but they are less likely to smoke or drink, and are less likely to report a functional limitation. FSU immigrants’ advantage in functional limitation is largely explained by their very high levels of education and marriage, indicating that selectivity is important to understanding the health of this population.

The protective effect of physical activity (PA) on risk of stroke remains controversial as a result of lack of insight into the sources of heterogeneity between studies. We performed a comprehensive meta-analysis of studies to (1) quantify the association between PA level and risk of stroke outcomes and (2) test the hypothesis that the association of PA level with stroke outcomes will be similar between men and women. The outcome measures are stroke incidence, stroke mortality, or both.Cohort studies were identified by searching MEDLINE and EMBASE (from 1986 to 2005) and meta-analysis conducted according to meta-analysis of Observational Studies in Epidemiology (MOOSE) group recommendations. Data were reported as pooled relative risk (RR) and 95% confidence intervals (CI) using random-effects models to assess the association of stroke outcomes with PA level. Heterogeneity was investigated, and sensitivity analysis was performed. Stratified analysis by gender was performed.Of 992 articles, 13 satisfied all eligibility criteria and were studied. Compared with low PA, moderate PA caused an 11% reduction in risk of stroke outcome (RR = 0.89, 95% CI 0.86-0.93, p0.01) and high PA a 19% reduction (RR = 0.81, CI 0.77-0.84, p0.01). Among the men, results showed a 12% reduction in risk associated with moderate PA (RR = 0.88, CI 0.82-0.94, p0.01) and 19% reduction for high PA (RR = 0.81, CI 0.75-0.87, p0.01). Among the women, results showed a 24% reduction in risk for high PA (RR = 0.76, CI 0.64-.89, p0.01). There was, however, no significant risk reduction associated with a moderate PA level in women.Increased PA level appears beneficial in reduction of risk of stroke and related outcomes. However, higher levels of PA may be required in women to achieve as significant a risk reduction as in men. An exercise regimen tailored to women to improve related physiological mechanisms will likely be beneficial.

The ability to sense the bitter taste of nicotine is an important component of addiction to, and withdrawal from, cigarette smoking. alpha-Gustducin and phospholipase C-beta2 (PLC-beta2), molecules involved in the taste transduction pathway, have been identified in airway epithelial solitary chemosensory cells (SCCs). Airway epithelial cells also express multiple nicotinic acetylcholine receptors (nAChRs). However, the relationship between nAChRs and molecules of taste transduction in response to nicotine is not known. This study was designed to determine whether nAChRs and the taste transduction molecules alpha-gustducin, PLC-beta2 and bitter taste receptors (T2R38) reside at sites of the intrapulmonary airways where interaction with the nicotine components of cigarette smoke is likely.We used the reverse transcription-polymerase chain reaction (RT-PCR) to detect alpha-gustducin, PLC-beta2 and T2R38 mRNA and immunohistochemistry to localize expression of these proteins by nAChR expressing cells of the airway.RT-PCR demonstrated the presence of mRNA for alpha-gustducin, PLC-beta2 and T2R38. Immunohistochemistry showed the expression of alpha-gustducin, PLC-beta2 and T2R38 by subsets of epithelial cells at all levels of the intrapulmonary airways including bronchi, terminal and respiratory bronchioles. Double labeling demonstrated the co-expression of alpha-gustducin with alpha3, alpha4, alpha5, alpha7 and beta2, as well as, PLC-beta2 and T2R38 with alpha4, alpha5 and beta2 nAChR subunits.These findings provide morphological evidence for the presence of molecules of the bitter taste transduction pathway in nAChR expressing SCCs of the intrapulmonary airways. These SCCs may, thus, constitute a peripheral component of the bitter taste signal transduction pathway for nicotine.

Slack (Slo 2.2), a member of the Slo potassium channel family, is activated by both voltage and cytosolic factors, such as Na(+) ([Na(+)](i)) and Cl(-) ([Cl(-)](i)). Since the Slo family is known to play a role in hypoxia, and since hypoxia/ischemia is associated with an increase in H(+) and CO(2) intracellularly, we hypothesized that the Slack channel may be affected by changes in intracellular concentrations of CO(2) and H(+). To examine this, we expressed the Slack channel in Xenopus oocytes and the Slo 2.2 protein was allowed to be inserted into the plasma membrane. Inside-out patch recordings were performed to examine the response of Slack to different CO(2) concentrations (0.038%, 5%, 12%) and to different pH levels (6.3, 6.8, 7.3, 7.8, 8.3). In the presence of low [Na(+)](i) (5 mM), the Slack channel open probability decreased when exposed to decreased pH or increased CO(2) in a dose-dependent fashion (from 0.28+/-0.03, n=3, at pH 7.3 to 0.006+/-0.005, n=3, P=0.0004, at pH 6.8; and from 0.65+/-0.17, n=3, at 0.038% CO(2) to 0.22+/-0.07, n=3, P=0.04 at 12% CO(2)). In the presence of high [Na(+)](i) (45 mM), Slack open probability increased (from 0.03+/-0.01 at 5 mM [Na(+)](i), n=3, to 0.11+/-0.01, n=3, P=0.01) even in the presence of decreased pH (6.3). Since Slack activity increases significantly when exposed to increased [Na(+)](i), even in presence of increased H(+), we propose that Slack may play an important role in pathological conditions during which there is an increase in the intracellular concentrations of both acid and Na(+), such as in ischemia/hypoxia.

Vascular occlusive diseases affect brain blood flow, brain metabolism and are associated with arterial ischemic stroke. This study was designed to measure the brain blood flow velocity, brain oxygenation, hemoglobin concentrations, hematocrit, and cell free hemoglobin at pre- and post-exchange red cell transfusion in an 18 year old male patient with sickle cell disease and moyamoya syndrome (MMS). Exchange transfusion increased cerebral oxygen saturation 12%, total hemoglobin concentration 2%, hemoglobin AA 80%, and reduced sickle (SS) hemoglobin 12%, arterializations 33%, and cell free hemoglobin 33%. Brain blood flow velocity values were unaffected by transfusion. These observations suggest that exchange transfusion increases the hemoglobin carrying capacity and reduces sickle hemoglobin and shunting of blood, which may improve the peripheral and cerebral oxygenation. Transfusion did not affect the brain blood flow in this patient. Therefore the risk of transient ischemic attack and arterial ischemic stroke from mms still exist.

In the present study, immunohistochemistry combined with retrograde labeling techniques were used to determine if hypoglossal motoneurons (HMNs), retrogradely labeled after cholera toxin B subunit (CTB) injection to the genioglossus muscle in rats, show immunoreactivity for alpha-7 and alpha-4 subunits of nicotinic acetylcholine receptors (nAChRs). CTB-positive HMNs projecting to the genioglossus muscle were consistently labeled throughout the rostrocaudal extent of the hypoglossal nuclei with the greatest labeling at and caudal to area postrema. Alpha-7 subunit immunoreactivity was found in 39.44 ± 5.10% of 870 CTB-labeled motoneurons and the alpha-4 subunit in 51.01 ± 3.71% of 983 CTB-positive neurons. Rostrally, the number of genioglossal motoneurons demonstrating immunoreactivity for the alpha-7 subunit was 45.85 ± 10.04% compared to 34.96 ± 5.11% at and caudal to area postrema ( P > 0.1). The number of genioglossal motoneurons that showed immunoreactivity for the alpha-4 subunit was 55.03 ± 4.83% at and caudal to area postrema compared to 42.98 ± 3.90% in rostral areas ( P = 0.074). These results demonstrate that nAChR immunoreactivity is present in genioglossal motoneurons and suggest a role for alpha-7 and alpha-4 subunits containing nAChRs in the regulation of upper airway patency.

Affective disorders often occur in combination with disrupted sleep-wake cycles and abnormal fluctuations in hypothalamic neurotransmitters. Hypocretin (orexin) is a hypothalamic neuropeptide linked to narcolepsy, a sleep-related disorder characterized by profound disturbances in the normal sleeping pattern and variable degrees of depression. Wistar-Kyoto (WKY) rats exhibit depressive characteristics and patterns of sleep disruption similar to that observed in depressed human patients. In this study we sought to determine whether the total number or the size of hypothalamic hypocretin neurons in WKY rats differ from their control, Wistar (WIS) rats. Immunocytochemical and stereological methods were applied to quantify hypocretin-1 containing neurons in the hypothalamus. The study revealed 18% fewer hypocretin-1 positive neurons as well as a 15% decrease in average neuronal soma size of hypocretin-1 producing cells in the hypothalamus of WKY rats compared to WIS rats. These findings support the view that reduced number or size of hypothalamic hypocretinergic neurons may underlie the disrupted sleep pattern associated with depressive characteristics in WKY rats.

In the present study, we determined whether alpha-7 subunit containing nicotinic acetylcholine receptors (nAChRs) are expressed by neurons within the pre-Botzinger complex (pre-BotC), bulbospinal, and phrenic motor nuclei in the rat. alpha-7 Immunohistochemistry combined with cholera toxin B (CTB), a retrograde tracer was used to detect expression of alpha-7 nAChRs by phrenic motor and bulbospinal neurons. Neurokinin-1 receptor immunoreactivity was used as a marker for pre-BotC neurons. Of the CTB-positive neurons in the phrenic nuclei, 60% exhibited immunoreactivity for alpha-7 nAChRs. Of the bulbospinal neurons in the paramedian reticular nuclei (PMn), gigantocellular nuclei (Gi), raphe nuclei, rostral ventrolateral medulla (RVLM) and nucleus tractus solitarius, 20-50% were found to express alpha-7 nAChR immunoreactivity. Of the peudorabies virus (PRV) labeled bulbospinal neurons in PMn, Gi, raphe and RVLM, 9-12% co-expressed alpha-7 nAChRs. Immunoreactivity for alpha-7 nAChRs was also detected in 57% of the neurokinin-1 receptor containing neurons presumed to reside in pre-BotC. These findings suggest that nicotinic cholinergic regulation of the chest wall pumping muscles may occur at multiple levels of the central nervous system.

We have previously reported that the anticholinergic properties of cocaine may be important in cocaine induced apneusis. We have studied the effects of the cholinergic muscarinic antagonist atropine (ATR) on cocaine induced apneusis at the caudal chemosensitive areas of the ventrolateral medulla oblongata (CVLM). Experiments were performed in urethane anesthetized and tracheotomized cats with the CVLM surgically exposed. Topical application of ATR (44 mM ) to the CVLM produced significant decrements in minute ventilation (V(E)) and mean arterial blood pressure (MABP) (P

Paroxysmal bi-parietal (vertex) discharges are evoked during sleep by full field stroboscopic light stimulation in approximately 20 per cent of children with a diagnosis of various seizure phenomena.

Physiological evidence has indicated that central respiratory chemosensitivity may be ascribed to neurons located at the ventral medullary surface (VMS); however, in recent years, multiple sites have been proposed. Because c-Fos immunoreactivity is presumed to identify primary cells as well as second- and third-order cells that are activated by a particular stimulus, we hypothesized that activation of VMS cells using a known adequate respiratory stimulus, H+, would induce production of c-Fos in cells that participate in the central pH-sensitive respiratory chemoreflex loop. In this study, stimulation of rostral and caudal VMS respiratory chemosensitive sites in chloralose-urethane-anesthetized rats with acidic (pH 7.2) mock cerebrospinal fluid induced c-Fos protein immunoreactivity in widespread brain sites, such as VMS, ventral pontine surface, retrotrapezoid, medial and lateral parabrachial, lateral reticular nuclei, cranial nerves VII and X nuclei, A1 and C1 areas, area postrema, locus coeruleus, and paragigantocellular nuclei. At the hypothalamus, the c-Fos reaction product was seen in the dorsomedial, lateral hypothalamic, supraoptic, and periventricular nuclei. These results suggest that 1) multiple c-Fos-positive brain stem and hypothalamic structures may represent part of a neuronal network responsive to cerebrospinal fluid pH changes at the VMS, and 2) VMS pH-sensitive neurons project to widespread regions in the brain stem and hypothalamus that include respiratory and cardiovascular control sites.

Subarachnoid space enlargement is a benign clinical entity characterized by rapid head enlargement in an infant with normal neurodevelopment. We report on two infants who had rapid increases in head circumference, family histories of macrocephaly, and normal neurodevelopment. Radiologic investigations in both infants showed subarachnoid space fluid collection but normal ventricular size. They both had a benign clinical course with resolution of the subarachnoid space fluid collection by the second year of life. The head circumference, however, remained at or above the 95th percentile. There is a need for pediatricians to be aware of this clinical entity and its benign nature.

The most widely advocated drug that has been developed to decrease and possibly reverse the crippling effect of stroke is recombinant tissue plasminogen activator (rt-PA). In the treatment of ischemic stroke, rt-PA must be administered within the first 3 hr after the onset of symptoms for optimal efficacy and avoidance of life-threatening cerebral hemorrhage. This study sought to determine whether African-American stroke victims presented for treatment within the first 3 hr. In the study, we identified some of the more common reasons for the lack of prompt presentation. A prospective survey of 103 randomly selected acute stroke patients was performed. We found that less than half of this population sought assistance in the emergency department in time to take advantage of rt-PA therapy. When confronted with symptoms that were consistent with acute stroke, many patients either chose to ignore them or thought that they were experiencing transient phenomena. Three factors were identified as possible reasons for the lack of prompt response: (a) a lack of information about available treatment options; (b) the inability to recognize the early warning signs of an impending stroke; and (c) denial of illness. This study may help to evolve strategies that must be instituted to better educate the community about the early recognition of stroke and available treatment alternatives.