Identifying barriers to healthcare delivery and access in the Circumpolar North: important insights for health professionals.

Lack of access to healthcare services for people living in the Circumpolar North may have important consequences for their health and well-being, both in terms of the actual treatment and other possible health-related consequences intertwined with their life situation. The aim of the present study was to identify the specific challenges to healthcare service delivery and access for populations in the Circumpolar North that are addressed in contemporary literature. A scoping review of literature published between 2005 and 2016 was conducted and 43 articles were selected for inclusion into the review. The review findings address 4 main themes identified in the literature: (1) the influence of physical geography, (2) healthcare provider-related barriers, (3) the importance of culture and language and (4) the impact of systemic factors. The review of the literature enabled us to identify existing gaps in both health service access and issues discussed in the available literature, particularly for informing healthcare services in the Circumpolar North, as well as point towards opportunities for future research. The thematic findings drawn from interdisciplinary and international literature inform understandings of the impact of health system barriers on healthcare services and the opportunities for Northern residents to support their own health.

A comparison of quartz OSL and isothermal TL measurements on Chinese loess.

The reliability of equivalent doses (De) from Chinese loess, measured using isothermal thermoluminescence (ITL) is tested. Dose calculations use the single-aliquot regenerative-dose (SAR) procedure. Despite good reproducibility of laboratory-induced signals and negligible response at zero dose, a significant overestimation of De is observed, compared with OSL measurements. Measurement of a known laboratory dose administered after optical bleaching, but before any heating, demonstrates that the first heating during measurement of the natural signal causes a significant sensitivity change, undetected by SAR. Using the single-aliquot regeneration and added (SARA) dose procedure, which allows for initial sensitivity change, good agreement with OSL is obtained after allowance is made for initial incomplete bleaching. It is concluded that SAR-ITL, in its present form, is not a suitable method for dating Chinese loess; it is very important to undertake a dose recovery test before any TL procedure is used to date sediments.

Na(+)-H+ exchanger and its role in essential hypertension and diabetes mellitus.

The Na(+)-H+ exchanger is a ubiquitous transport system that is involved in the regulation of intracellular pH, cell growth and proliferation, cell volume regulation, and transepithelial absorption of Na+, Cl-, and HCO3-. Altered activity of the Na(+)-H+ exchanger has been implicated as a mechanism contributing to the development of high blood pressure in subgroups of patients with essential hypertension and in various animal models of hypertension. Many of these studies measured Na(+)-Li+ exchange rather than Na(+)-H+ exchange, hypothesizing that Na(+)-Li+ exchange represents a functional mode of the Na(+)-H+ exchanger. However, this is a controversial assumption. Several studies have also shown an association between erythrocyte Na(+)-Li(+)-exchange rate and predisposition to nephropathy in patients with insulin-dependent diabetes mellitus. The recent cDNA cloning of at least one isoform of the Na(+)-H+ exchanger will help clarify the cellular mechanisms of regulation of the exchanger and its possible role in pathophysiological states such as hypertension.

Effect of prolonged dietary administration of vanadate on blood pressure in the rat.

Vanadate, a potent naturally occurring Na+,K+-ATPase inhibitor thought to have a role in regulating Na+-K+ pump activity, was fed to uninephrectomized rats drinking tap water or a 1% solution of sodium chloride for as long as 56 weeks. Feeding was achieved by adding sodium orthovanadate to normal rat chow equivalent to 100 or 200 ppm vanadium by weight. In the rats drinking tap water, systolic pressure gradually increased over a period of several weeks and then was sustained in a dose-related manner for the duration of the treatment. The increased pressure was not associated with changes in water intake, urine output, or urinary sodium excretion but correlated positively with plasma vanadium levels ranging from 0.04 to 0.27 microgram/ml. Increased pressure was associated with increased heart-to-body-weight ratio but did not appear to occur in a small group of animals drinking the 1% solution of sodium chloride. These findings, considered in the light of others, indicate that vanadate deserves continued study in relation to hypertension.

Metabolic complications of urinary diversions: an overview.

Patients with urinary diversions present unique challenges to internists who have an important role in their long-term management. Advances in surgical techniques over the past 30 years have given rise to a number of urinary diversion procedures that use various intestinal segments. In its normal function, the intestine absorbs water and solutes. When placed in contact with the urinary stream, the intestine can create numerous metabolic abnormalities. These include bone disease, hepatobiliary disease, infection, malignancy, neurologic complications, nutritional deficiencies, and a number of electrolyte and acid-base disorders. An overview of these metabolic abnormalities and their causes is provided, as well as recommendations for screening and management of patients.

Decreased myocardial Na+K+ATPase activity in rats with reduced renal mass-saline hypertension.

Inhibition of cardiovascular Na,K-pump activity has been shown to promote an increase in the contractile activity of myocardial and vascular smooth muscle and a consequent rise in blood pressure (BP). It has also been shown that vascular Na,K-pump activity and myocardial Na+K+ATPase activity [the energy source for active sodium (Na) and potassium (K) transport] are decreased in rats with various forms of low renin hypertension including rats with reduced renal mass-saline (RRM-saline) hypertension. In the present study, left ventricular Na+K+ATPase activity from rats with RRM-saline hypertension was found to be decreased in membranes prepared by two independent methods: deoxycholate, sodium iodide (Nal)-treated microsomal fractions (method 1) and membranes prepared by the hypotonic, lithium bromide (LiBr) method (method 2). Relative to RRM normotensive control rats which drank distilled water, myocardial Na+K+ATPase activity from RRM-saline drinking rats was decreased by 18.2% in membranes prepared by method 1 and 33.6% in membranes prepared by method 2. The apparent affinities of Na+K+ATPase for K and for ouabain were unaltered relative to controls in membranes prepared from these hypertensive rats by method 1, and the sialic acid content and 5'-nucleotidase activity (two putative sarcolemmal markers) were unaltered in membranes from the hypertensive rats, prepared by methods 1 and 2 respectively. The Mg2+ATPase activity of membranes prepared by method 1 was increased in the RRM-saline hypertensive rats but because it was not increased in membranes prepared by method 2 the former observation does not appear to be of any pathophysiological importance. In other experiments, hypertension was reversed in RRM-saline hypertensive rats by restricting their salt intake (substitution of distilled water for drinking).(ABSTRACT TRUNCATED AT 250 WORDS)

Humoral Na+-K+ pump inhibitory activity in essential hypertension and in normotensive subjects after acute volume expansion.

Plasma from black male patients with essential hypertension was bioassayed for vascular Na+-K+ pump inhibitory activity. Halves of the same rat tail artery were incubated for two hours in boiled plasma supernates from a hypertensive patient and a paired age-, sex-, and race-matched normotensive subject and then ouabain-sensitive 86Rb uptake was measured. Ouabain-sensitive 86Rb uptake by their leukocytes was also measured. Eighteen pairs of subjects were studied. The uptakes were not significantly different in the hypertensive patients and control subjects. However, when we selected from the eighteen hypertensive patients, nine with low plasma renin activity on the day of the study, uptakes were reduced in the hypertensive patients relative to the paired control subjects. We also assayed plasma supernates from normotensive black and white male subjects before and after acute volume expansion (2.5 L saline IV + 1.5 L distilled water orally over a three-hour period) and from paired normotensive subjects before and after sham volume expansion and obtained a positive bioassay in the expanded subjects both on intraindividual and interindividual comparisons. These studies demonstrate increased vascular Na+-K+ pump inhibitory activity in the plasma of black male patients with low renin essential hypertension and in the plasma of normotensive subjects after acute volume expansion. The findings suggest that the inhibitory activity in the hypertensive subjects' plasma is related to volume expansion, relative or absolute.

The effect of gamma-acetylenic GABA, an enzyme-activated irreversible inhibitor of GABA-transaminase, on dopamine pathways of the extrapyramidal and limbic systems.

gamma-Acetylenic GABA (100 mg/kg i.p.) inhibited GABA-transaminase activity and caused a several-fold increase in the concentration of GABA in rat brain. This increased GABA concentration was associated with a decreased rate of dopamine depletion following alpha-methyl-p-tyrosine treatment and a decrease in homovanillic acid in extrapyramidal and limbic structures suggesting a decrease in dopamine turnover in both pathways. In addition, gamma-acetylenic GABA injected into the ventral mesencephalic tegmentum decreased dopamine turnover in the mesolimbic forebrain. These results are consistent with a modulatory function of GABAergic neurons on extrapyramidal and limbic dopamine pathways. Inhibitory effects on dopaminergic functions of the extrapyramidal and limbic systems were also indicated by the amphetamine and apomorphine-induced ipsilateral turning after unilateral substantia nigral injections of gamma-acetylenic GABA and by the attenuation of dopamine-induced hypermotility after bilateral injections of gamma-acetylenic GABA into the nucleus accumbens.

Total GABA and homocarnosine in CSF as indices of brain GABA concentrations.

Treatment of rats with gamma-vinyl-GABA, an inhibitor of GABA-transaminase, caused a dose- and time-related increase in brain GABA concentrations concomitant with increases in the concentrations of total GABA and homocarnosine in the CSF. At 18 h after treatment both CSF parameters correlated significantly with brain GABA concentrations. However, only total GABA in CSF accurately reflected brain GABA concentrations as a function of time after treatment and is therefore the preferred index.

Role of a humoral sodium-potassium pump inhibitor in experimental low renin hypertension.

Recent evidence suggests that the vascular sodium-potassium pump suppression previously observed in animals with various models of low renin hypertension results from a circulating heat stable ouabain-like agent. It appears to come from or be influenced by the anteroventral third ventricle area of the brain and its action on blood vessels results in depolarization of the smooth muscle cell. Suppression of the vascular sodium-potassium pump, with ouabain for example, increases contractile activity and the contractile responses to vasoactive agents. Thus the humoral pump inhibitor may be involved in the genesis and maintenance of experimental low renin hypertension.

Effects of gamma-vinyl GABA on food intake of rats.

Gamma-vinyl GABA, an inhibitor of GABA-transaminase, produced a dose-related reduction of food intake in rats, after both single, (125-1000 mg/kg IP or 500 mg/kg PO) and repeated (250 mg/kg/day IP) administration. No tolerance was observed to the effect of repeated injections. Catecholamine and indoleamine systems in the CNS do not appear to be implicated in this anorexic effect. Combination of gamma-vinyl GABA with amphetamine (2.5 mg/kg) enhanced the anorexic effects of the latter compound whilst attenuating its stimulant effects. The data suggest an important role for GABA in the control of food intake.

Characterization of a synthetic bioactive polymer by nonlinear optical microscopy.

Tissue Engineering is a new emerging field that offers many possibilities to produce three-dimensional and functional tissues like ligaments or scaffolds. The biocompatibility of these materials is crucial in tissue engineering, since they should be integrated in situ and should induce a good cell adhesion and proliferation. One of the most promising materials used for tissue engineering are polyesters such as Poly-ε-caprolactone (PCL), which is used in this work. In our case, the bio-integration is reached by grafting a bioactive polymer (pNaSS) on a PCL surface. Using nonlinear microscopy, PCL structure is visualized by SHG and proteins and cells by two-photon excitation autofluorescence generation. A comparative study between grafted and nongrafted polymer films is provided. We demonstrate that the polymer grafting improves the protein adsorption by a factor of 75% and increase the cell spreading onto the polymer surface. Since the spreading is directly related to cell adhesion and proliferation, we demonstrate that the pNaSS grafting promotes PCL biocompatibility.

The use of temperature as a discharge criterion for ambulatory surgery patients.

Evaluating each patient's return to an acceptable state after surgical and anesthetic intervention is the responsibility of the postanesthesia nurse. Postanesthesia nurses use criteria to determine ambulatory surgical patient readiness to be discharged from phase I recovery to phase II recovery and from phase II recovery to home. Temperature is one indicator of postanesthesia recovery. Temperature discharge criteria from phase I postanesthesia recovery have been reported. However, temperature discharge criteria for phase II postanesthesia recovery have been adapted from phase I standards and nursing traditions. This study sought to describe the postoperative temperatures of ambulatory surgical patients from admission to phase II postanesthesia recovery to discharge home. A convenience sample of 101 adult patients undergoing surgery at a hospital-based ambulatory surgical unit (ASU) participated. Tympanic temperature was measured preoperatively on admission to the ASU, postoperatively, at the beginning of phase II postanesthesia recovery, and at the end of phase II postanesthesia recovery immediately before discharge home. All subjects were normothermic during phase II postanesthesia recovery, with temperatures ranging from 36.0 degrees C (96.8 degrees F) to 38.3 degrees C (101 degrees F). Paired Student's t Test showed significant differences (P < .0001) between temperature means. There was a 0.38 degrees C (0.7 degree F) decrease between preoperative admission temperature and temperature on admission to phase II postanesthesia recovery. During phase II postanesthesia recovery the mean temperature increased 0.16 degree C (0.3 degree F) before discharge home. However, the clinical and practical implications of these findings is questionable.(ABSTRACT TRUNCATED AT 250 WORDS)

Periventricular forebrain mechanisms for blood pressure regulation.

Periventricular forebrain regions participate in body fluid and cardiovascular regulatory mechanisms that are intimately related to neural participation in experimental hypertension. Ablation of preoptic-hypothalamic periventricular tissue surrounding the anteroventral third ventricle (AV3V) disrupts both angiotensin (AngII) and sodium regulatory mechanisms and prevents experimental hypertension in either renin-dependent or -independent models. When AV3V is spared, and central AngII pressor mechanisms are interrupted by subfornical organ ablation or anterior hypothalamic knife cuts, renin-dependent but not renin-independent models of hypertension are prevented. Volume-expanded models of hypertension may be mediated by a natriuretic hormone that also inhibits the sodium-potassium pump in vascular smooth muscle, resulting in increased vasoconstriction. Volume expansion-induced release of this humoral ATPase inhibitor is attenuated in rats with AV3V lesions. In the renin-independent, reduced renal mass model, development of hypertension is correlated with increased plasma levels of sodium-potassium pump inhibitor. AV3V ablation blocks both the hypertension and the increase in humoral ATPase inhibitor. Thus, Thus, central angiotensin pressor and natriuretic mechanisms overlap in AV3V, and prevention of renin-dependent and volume-dependent models of experimental hypertension by AV3V ablation appears linked to disruption of these functionally separable systems.

Value of monoamine metabolite determinations in CSF as an index of their concentrations in rat brain following various pharmacological manipulations.

Using reversed-phase high performance liquid chromatography with electrochemical detection it is possible to measure concomitantly the concentration of several monoamines, their metabolites and aminoacid precursors in 100 microliters of rat cerebrospinal fluid. To study the quantitative relationship between CSF and brain, alterations in brain monoamines and monoamine metabolites were effected by treatment with L-DOPA or L-5HTP administered with or without concomitant inhibition of extracerebral aromatic amino acid decarboxylase and by treatment with alpha-monofluoromethyldopa, probenecid, haloperidol, or probenecid plus haloperidol. The concentrations of the monoamine metabolites, 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic acid, and homovanillic acid as well as of the L-DOPA metabolite, 3-methoxy-4-hydroxyphenylalanine in the cerebrospinal fluid were linearly correlated with the concentrations of these metabolites in the brain. However, these correlations need to be interpreted cautiously, since the slopes of the individual regression lines obtained after different pharmacological treatments differed significantly.