Prostaglandins and (PG) have been reported to be an important gastric acid suppressive factor. However, the mechanism underlying
is yet to be clearly established. In vitro study with gastric microsomes in presence of both PGE2 and PGI2 shows a stimulation of gastric H+ K+-ATPase activity below 1X10−6M and 2.5X10−7M concentrations respectively. However, with further increase in concentrations of both PGE2 and PGI2, H+, K+-ATPase activity shows an inhibition but PGI2 completely obliterates the K+ stimulated part of H+, K+-ATPase activity at higher concentration. The H+-ion transport study using chambered frog gastric mucosa shows that both PGE2 and PGI2 inhibit H+-ion transport at 5X10−6 M and 10X10−6M concentrations respectively but the effect of PGI2 is reversible. These differential effects of PGE2 and PGI2 on microsomal H+, K+-ATPase and on H+ transport my be caused by the differential effects of these phospholipid mediators with the gastric mucosal cell membrane.
This in vitro investigation shows the role of prostaglandin (s) as a physiological switch/regulator of gastric H+ ion transport leading to the cessation of gastric acid secretion. 相似文献
This study sought to investigate the effects of α-stat and pH stat regimens on cardiac outcome during moderate hypothermic
cardiopulmonary bypass. 100 patients undergoing elective coronary artery bypass grafting (CABG) were randomly assigned with
respect to the target value for PaCO2 during cardiopulmonary bypass (CPB) into 2 groups. In 50 patients the target PaCO2 was 40 mmHg, measured at a standard electrode temperature of 37°C while in the other 50 patients the target PaCO2 was 40 mmHg, corrected to the patients nasopharyngeal temperature (lowest value reached: 32±0.5°C). There were no significant
differences between groups with regards to cardiac outcome such as appearance of new ‘Q’ waves on the electrocardiogram, postoperative
creatinine kinase-MB fraction, systemic vascular resistance (SVR), cardiac index (Cl), need for inotropic or intra-aortic
balloon pump support and the length of postoperative ventilation or intensive care unit stay. These findings support the hypothesis
that CO2 management during CPB at moderate hypothermia has no clinically significant effect on cardiac outcome. 相似文献
The present study was designed to compare the potential of turmeric and its active principle curcumin on T3-induced oxidative stress and hyperplasia. Adult male Wistar strain rats were rendered hyperthyroid by T3 treatment (10 μg · 100 g−1 · day−1 intraperitoneal for 15 days in 0.1 mM NaOH) to induce renal hyperplasia. Another two groups were treated similarly with T3 along with either turmeric or curcumin (30 mg kg−1 body weight day−1 orally for 15 days). The results indicate that T3 induces both hypertrophy and hyperplasia in rat kidney as evidenced by increase in cell number per unit area, increased protein
content, tubular dilation and interstitial edema. These changes were accompanied by increased mitochondrial lipid peroxidation
and superoxide dismutase activity without any change in catalase activity and glutathione content suggesting an oxidative
predominance. Both turmeric and curcumin were able to restore the level of mitochondrial lipid peroxidation and superoxide
dismutase activity in the present dose schedule. T3-induced histo-pathological changes were restored with turmeric treatment whereas curcumin administration caused hypoplasia.
This may be due to lower concentration of curcumin in the whole turmeric. Thus it is hypothesized that regulation of cell
cycle in rat kidney by T3 is via reactive oxygen species and curcumin reveres the changes by scavenging them. Although the response trends are comparable
for both turmeric and curcumin, the magnitude of alteration is more in the later. Turmeric in the current dose schedule is
a safer bet than curcumin in normalizing the T3-induced hyperplasia may be due to the lower concentration of the active principle in the whole spice. 相似文献
The effect of iodine deficiency (ID) on thyroid function in African women during pregnancy and postnatal period was examined,
for which very limited information is available. Serum T4, T3, TSH, TBG, thyroxine binding capacity (TBK), free thyroxine index (FT4I=T4/TBK) and T4/TBG were determined by ELISA technique in 32 pregnant women (resident of Plateau state, Nigeria- an ID zone) through pregnancy
upto term delivery, and in 5 women up to 6 weeks post delivery. Urinary iodide level was measured at delivery to determine
the degree of iodine deficiency. Results were matched with a non pregnant control comprising 44 subjects. 5555 birth weights
(BW) of term babies in the region were analysed to determine the prevalence of ‘small for dates’ (SFD) babies in the population.
Results show that the level of serum FT4I was elevated very significantly at late gestation (P<.001) but the women were not hyperthyroid, suggesting a marked disturbance
in binding of T4 with TBG during pregnancy. Five women with SFD babies were found in ‘compensated hypothyroid state’ and showed a significant
depression (p<.01) in serum T4/TBG, T4, FT4I and T3 levels to a low normal range, with a concurrent significant rise (p.<.001) in TSH level (above normal range) throughout pregnancy.
Incidence of SFD babies was higher (p.<.001) in ID zone (Bassa 15.2%) compared to control zone (Jos 9.8%). It is concluded
that a state of maternal ‘subclinical (compensated) hypothyroidism’ during pregnancy possibly plays an important role in the
aetiopathogenesis of SFD babies in Africans. A normal reference range for thyroid parameters at various stages of pregnancy
in healthy African women is established for the first time. 相似文献
In view of several reports that there is a lack of balance in free radicals in case of bronchial asthma (1) the effect of
free radicals on cell membrane was studied by estimating the membrane bound protein Na+, K+-ATPase activity and the intracellular sodium level in patients of bronchial asthma before and after a short course (one week)
of oral corticosteroid (prednisolone 0.75–1mg/kg body weight) therapy. Results showed that there is a definite statistically
significant rise in free radical level and intracellular sodium level and a significant lowering of Na+, K+-ATPase activity in case of untreated bronchial asthma. After short course of therapy with oral corticosteroids, the free
radical level and intracellular sodium level decreased significantly, together with a significant rise of the Na+, K+-ATPase activity. Also, a significant negative correlation (r=−0.74) between the lipid peroxide level and the Na+,-K+-ATPase activity was found in these cases. 相似文献
Oxygen derived free radicals have been implicated in a number of clinical disorders including atherosclerosis (1), ischemic
heart disease (IHD) (2), post ischemic reperfusion injury (3) and respiratory distress syndrome (4). These radical are generated
by sequential reduction of molecular oxygen; the primary product being superoxide anion (O2.−) which is subsequently reduced to hydrogen peroxide (H2O2), hydroxy1 radical (OH.) and singlet oxygen (1O2). However the evidence for ODFR induced cell damage in various clinical disorders is still debated and rests largely on free
radical scavenging studies, through electron paramagnetic resonance spectroscopic (EPRS) studies have provided direct evidence
for ODFR generation following coronary artery ligation (5).
By definition, a free radical is an atom, ion or molecule with one or more unpaired electrons (the presence of unpaired electron
in a free radical being represented by a superscribed bold dot-R.) and may be formed as a result of homolytic fission of a covalent bond or by electron transfer reactions, and may have cationic
(NH3+), anionic (O2.−) or neutral (NO) characteristics. The most important in vivo source for these radical species have been found to be univalent
biochemical redox reactions involving oxygen. (a) A:B→A.+B. (b) A:+B→A.+B.相似文献
In this paper, we use the coincidence degree theory to establish new results on the existence of T-periodic solutions for the Rayleigh equation with two deviating arguments of the form
The synergistic effects of hemoglobin, carbonic anhydrase and the band 3 protein make red blood cells the ideal vehicle for oxygen delivering to the tissues. As long as oxygen is supplied by these ideal vehicles, oxygen intoxication of the tissues is precluded. Band 3 protein mediates the “Chloride-Shift”, i.e., the anion exchange of Cl−/HCO3−. Because of the Chloride-Shift, red blood cells are able to recognize metabolically active tissues and to supply the minimum amount of oxygen to the tissues. Investigation into the molecular mechanisms of the anion exchange mediated by the band 3 protein was introduced. 相似文献
Cytokines, viral load and opportunistic infections play an important role in HIV-disease progression. Hundred children vertically
infected with HIV were enrolled to determine mRNA levels of TNF-α, IL-10, IL-4 and IFN-γ. These levels were estimated by amplifying
cytokine mRNA from peripheral blood mononuclear cells. Severity of HIV was staged by the reduction in CD4+ T cells and the onset of opportunistic infections. IL-10 mRNA levels were observed to increase with the severity. Despite
the rising IL-10 mRNA levels, TNF-α mRNA levels increased with severity of HIV and decrease in CD4+ T cell counts. IL-4 mRNA levels increased with the reduction in CD4+ T cell numbers. Depleting mRNA levels of IFN-γ contributed to the worsening of HIV disease. Increase in TNF-α and IL-4 levels
appended to the disease severity by upregulation of the viral replication. Increased IL-10 levels and decreased IFN-γ levels
predisposed the children to HIV associated opportunistic infections, which in return contributed to cytokine disarray. 相似文献
If T maps a convex domain DT into itself, and if {ωn} is a real sequence with range in (0, 1] then the recursive averaging process, generates a sequence {x?n}; with range in DT. Under suitable conditions on DT, T and {ωn} the sequence {x?n} will converge in some sense to a fixed point of T. We prove that if DT is a closed convex subset of a complex Hilbert space H, if Tω = (1 ? ω) I + ωT is a strict contraction for some ω ? (0, 1], and if {ωn} satisfies the conditions, and then, for arbitrary ξ ? DT, {x?n} converges strongly to (the unique) fixed point of T. We also prove that if DT and {ωn} satisfy the foregoing conditions, if T has at least one fixed point, and if Tω is non-expansive for some ω ? (0, 1], then for all ξ ? DT, {x?n} converges at least weakly to some fixed point of T. Finally, we apply these results to linear equations involving bounded normal operators and obtain an extension of the classical Neumann operator series. 相似文献
This paper is a continuation of a previous paper published in this JOURNAL. The basic idea in the two papers is to enlarge the assemblage of thermodynamic states by including the so-called “metastable” states. Considering a system, in one or two phases, which has a single type of transformation, the writer develops an equation of state of the form η = a + by + cp + dpv + (e + fv + gp + hpv) In T, where p, v, T are three independent variables, and a, b, c, etc. are constants.The latent heat at p, T = constant is λP,T = I (v2 -v1) [b+db+(f+hp) InT), which is derived from the equation of state.The available thermodynamic data on ammonia and steam are used to check these equations. It is found that within the saturated region the agreement is quite satis factory, whereas for the superheated region the agreement is not so good. 相似文献
Plasma levels of lipids, lipoproteins and lipid peroxides and erythrocyte Na+−K+ ATPase, Mg2+ATPase and antioxidant enzymes were measured in type-2 diabetic patients. A significant decrease in Na+-K+-ATPase activity was observed in diabetic patients which was negatively correlated with blood glucose and lipid peroxides,
while the Mg2+-ATPase activity was increased. In the diabetic subjects the plasma concentrations of Na+ and K+ were increased where as erythrocyte levels of Na+ were increased and K+ were decreased. Hyperlipidaemia and increased levels of lipid peroxides were observed in the diabetic subjects. There was
a significant increase in erythrocyte catalase activity in diabetics which positively correlated with their lipid peroxides.
There was no change in GPx activities between controls and diabetics. 相似文献
Contact interface properties are important in determining the performances of devices that are based on atomically thin two-dimensional (2D) materials, especially for those with short channels. Understanding the contact interface is therefore important to design better devices. Herein, we use scanning transmission electron microscopy, electron energy loss spectroscopy, and first-principles calculations to reveal the electronic structures within the metallic (1T′)-semiconducting (2H) MoTe2 coplanar phase boundary across a wide spectral range and correlate its properties to atomic structures. We find that the 2H-MoTe2 excitonic peaks cross the phase boundary into the 1T′ phase within a range of approximately 150 nm. The 1T′-MoTe2 crystal field can penetrate the boundary and extend into the 2H phase by approximately two unit-cells. The plasmonic oscillations exhibit strong angle dependence, that is a red-shift of π+σ (approximately 0.3–1.2 eV) occurs within 4 nm at 1T′/2H-MoTe2 boundaries with large tilt angles, but there is no shift at zero-tilted boundaries. These atomic-scale measurements reveal the structure–property relationships of the 1T′/2H-MoTe2 boundary, providing useful information for phase boundary engineering and device development based on 2D materials. 相似文献
Given the linear system = Ax - bu, y = cTx, it is shown that, for a certain non-quadratic cost functional, the optimal control is given by uopt(x) = h(cTx), where the function h(y) must satisfy the conditions ky2?h(y)y>0 for y≠0, h(0) = 0 and existence of h-1 everywhere. The linear system considered must satisfy the Popov condition 1/k + (1 +?ωβ) G(?ω)>0 for all ω, G(s) being the y(s)/u(s) transfer function. 相似文献
Benign prostate hyperplasia (BPH) is a common condition in aged men and result from prolong chronic inflammation in prostate
gland. Cytokines are important molecules responsible for inflammation. Single nucleotide polymorphisms (SNPs) in promoter
region of cytokine genes have been shown to alter the level of cytokines. Hence we evaluated the association of pro-inflammatory
and anti-inflammatory cytokine SNPs in a North Indian cohort of BPH patients. We observed that IL-1B −511 CT + TT genotypes conferred protective effect for susceptibility to BPH (OR 0.39, P 0.001). Our results also demonstrated that TNF-A −1031 C allele to be associated with risk for BPH (OR 1.89, P < 0.0001). Moreover, we also observed twofold risk for IL-10 −1082 cytokine gene polymorphism (OR 1.96, P 0.048). No association was observed with risk of BPH for IFN-G +874, IL-1 RN VNTR, IL-6 −174, IL-10 −819 and TGF-B +28. Our findings of IL-1B −511, TNF-A −1031 and IL-10 −1082 suggested that these variants play important role in susceptibility to BPH. Future studies in large cohort of different
ethnicity BPH groups are warranted to establish definite associations with other cytokine gene polymorphisms as well. 相似文献
348 patients of chronic obstructive pulmonary diseases (COPD) were studied for their acid base profile using ABL-3 blood gas
analyser (Radiometer, copenhagan). 185 patients (53.1%) had simple disorders (respiratory acidosis—53%, respiratory alkalosis—25.4%,
metabolic acidosis—11.3%, metabolic alkalosis—10.2%). Mixed disorders were present in 131 patients (34.9%) (respiratory acidosis
and metabolic acidosis—75.2%, respiratory acidosis and metabolic acidosis—14%, metabolic acidosis and metabolic alkalosis—5.7%,
metabolic alkalosis and respiratory alkalosis—4.9%). Hypoxemia without other acid base abnormalities was observed in early
patients of GOPD (42 patients—12%). Chronic respiratory acidosis was the most common finding in advanced cases of COPD (98%).
An almost equal number of such patients had a mixed disorder of respiratory acidosis with metabolic alkalosis (91%). Salt
restriction, prolonged use of steriods and hypokalemia were often related to metabolic alkalosis in such patients. 相似文献
Fixed point properties of the binomial function are developed. It is shown that for any 1 < L < N, TLNhas a unique fixed point p? in (0, 1), and that for large N, the fixed point is L/N. This has application to signal detection schemes commonly used in communication systems. When detecting the presence or absence of a signal with an initial false alarm probability pFAand an initial detection probability pD, then TLN(pFA) < pFAand TLN(pD) > pDif, and only if, pFA < p? < pD. When this condition is satisfied, as N → ∞, TLN(pFA) → 0 and TLN(pD → 1. 相似文献
We evaluated the effect of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin.
Materials and methods:
In this multi-step experimental study, percent dilution ratios (PDRs) and final heparin concentrations (FHCs) were calculated by gravimetric method for determining the effect of syringe volume (1, 2, 5 and 10 mL), needle size (20, 21, 22, 25 and 26 G) and sample volume (0.5, 1, 2, 5 and 10 mL). The effect of different PDRs and FHCs on blood gas and electrolyte parameters were determined. The erroneous results from nonstandardized sampling were evaluated according to RiliBAK’s TEa.
Results:
The increase of PDRs and FHCs was associated with the decrease of syringe volume, the increase of needle size and the decrease of sample volume: from 2.0% and 100 IU/mL in 10 mL-syringe to 7.0% and 351 IU/mL in 1 mL-syringe; from 4.9% and 245 IU/mL in 26G to 7.6% and 380 IU/mL in 20 G with combined 1 mL syringe; from 2.0% and 100 IU/mL in full-filled sample to 34% and 1675 IU/mL in 0.5 mL suctioned sample into 10 mL-syringe. There was no statistical difference in pH; but the percent decreasing in pCO2, K+, iCa2+, iMg2+; the percent increasing in pO2 and Na+ were statistical significance compared to samples full-filled in syringes. The all changes in pH and pO2 were acceptable; but the changes in pCO2, Na+, K+ and iCa2+ were unacceptable according to TEa limits except fullfilled-syringes.
Conclusions:
The changes in PDRs and FHCs due nonstandardized sampling in syringe washed with liquid heparin give rise to erroneous test results for pCO2 and electrolytes. 相似文献
