Journal of Basic and Clinical Physiology and Pharmacology最新文献

Objectives: High-risk pulmonary embolism (PE) is known as the presence of hemodynamic instability and has a high mortality rate, which necessitates immediate reperfusion treatment. According to current PE treatment guidelines, alteplase is the approved and preferred agent for systemic thrombolysis. Herein, we present the efficacy and safety of systemic thrombolysis with reteplase in patients with high-risk PE.

Methods: The present retrospective observational study includes 30 patients with high-risk acute PE undergoing systemic thrombolysis with reteplase. All patients were in obstructive shock. The thrombolytic regimen consisted of two bolus doses of 10 U reteplase, given 30 min apart, followed by intravenous heparin.

Results: All patients had elevated cardiac troponin levels. D-dimer levels were elevated in 28 (93.3 %) patients. Systolic blood pressure increased after thrombolysis with reteplase, and the dyspnea, tachypnea, and coughing improved in all patients. Mean SPO₂ was 83.6 ± 6.96 % before treatment, which had risen to 95.7 ± 1.29 % after thrombolysis (p=0.059). Right ventricular dilatation was seen in all patients at presentation, which improved by 96.6 % after treatment and systolic pulmonary artery pressure decreased significantly in all patients at discharge. None of the patients needed to repeat thrombolytic therapy. There were no major hemorrhagic complications or death after thrombolysis, while 5 (16.7 %) patients experienced minor self-limiting bleeding.

Conclusions: Reteplase, as two bolus injections of 10 U given 30 min apart, is an effective thrombolytic regimen in treating acute high-risk PE with a low risk of major hemorrhagic complications.

The quantification of 0 2 toxicity as a function of exposure time (t) and Po2 has been based mainly on the empirical rectangular hyperbola. The non-linear response of the 02-damaged physiological variable (DMG) as a function of time at constant Po2 can be related to the dependence of dDMG/dt on the DMG. The kinetics of the 02 - derived chemical species suggests a power relationship between the DMG and Po2 rather than a linear relationship. The combination of time and Po2 considerations suggests two models: 1) DMG = a(ebt - l)Po2 c and 2) DMG = a-tbPo2 c, where a, b and c are constant. Non-linear regression of the different parameters of 0 2 toxicity showed a preference for model 2, with b=2. Possible mechanisms underlying the kinetics of 0 2 toxicity and the use of the equation for its prediction are discussed.

The pathophysiological responses to immune stress (IS) include activation of several processes which are dependent on cytosolic Ca2+ elevation. Magnesium frequently acts as a natural Ca2+ antagonist. In this study we have observed that Mg2 + can protect guinea-pigs against IS. Antigen-sensitized guinea-pigs, which had been fed a magnesiumdeficient diet, were given a single dose (15 mg) of MgCl2 intraperitoneally 1 h before antigen challenge. The development of anaphylactic shock (AS) was observed during the next 2 h, and the hearts were subsequently examined histologically for signs of cardiac myolysis (CM). Magnesium (i) reduced the incidence of CM from 40% to 10% (p<0.05); (ii) reduced the incidence of AS from 61% to 35% (p<0.05); (iii) attenuated the severity of the AS; and (iv) lowered mortality from 39% in the control to 19% in the Mg2+-treated group (p=0.1). Serum and tissue total [Mg2+] were not affected by the administration of MgCl2. Also, the serum and heart Mg2+ levels were the same whether or not the guinea-pigs developed AS or CM. In cell culture we demonstrated that by elevating the [Mg2+] in the medium bathing sensitized rat basophilic leukemia (RBL) cells, the increase in cytosolic [Ca2+] subsequent to antigen challenge was reduced from 174 ± 23.28% (1 mM) to 82.74 ± 13.22 % (3 mM). We conclude that a single treatment with Mg2+ can considerably diminish damage induced by immune stress, probably by its altering the Ca2+: Mg2+ratio. Since the physiological reaction to different types of stress is similar, Mg2 + could prove beneficial in preventing stress-induced shock in general. Studies examining the mechanisms by which Mg2 + exerts its effects thus provide a scientific basis for the current clinical use of Mg2 + in acute myocardial infarction (AMI) and asthma.

Ventricular fibrillation (VF) is a major cause of sudden cardiac death in humans. Currently used antiarrhythmic drugs are aimed at preventing initiation of VF by decreasing the incidence of arrhythmias which can lead to VF. This approach today seems to be insufficient. On the basis of reports that VF can terminate spontaneously in various mammals, and even in humans, we propose pharmaceutical enhancement of self-ventricular defibrillation as a new therapeutical approach. Data obtained over the last decade indicate that a high cardiac extraneuronal norepinephrine level during VF facilitates selfdefibrillation. Dibenzazepines (tricyclic antidepressants) and phenothiazines elevate norepinephrine level by inhibiting norepinephrine reuptake and were found to exhibit defibrillatory activity. The relationship of chemical structure to defibrillatory activity was studied in a group of dibenzazepine and phenothiazine compounds.

Four types of ion-selective channels were found by the patch-clamp technique in the human erythroleucemia K562 cells. I)In cell-attached configuration at potentials less negative than -40 mV an 8 pS channel was detected. The potential dependence of channel activity suggests that this is the TTX-sensitive Na+ channel. II)A cation-selective channel was observed with equal permeability for Na+ and K+ and a potential-independent single-channel conductance of 19 pS. The channel is activated by intracellular Ca2+ and inhibited by TEA. ΙΠ)A predominantly anion-selective channel was identified with the selectivity sequence N03" >J" > G" = Br » S04 2·. The single-channel conductance shows outward rectification, and is in symmetrical NaCl solution 19 pS at -60 mV and 54 pS at +50 mV. The open- and closedtime distributions suggest one open and at least four closed states. At submicromolar concentrations, the open state is blocked by H2DIDS leading to channel flicker between open and blocked channel; higher concentrations (apparent Kj=6.8 μΜ) lead to a longer-lasting blocked state. Both components of inhibition are reversible. IV)In addition, an 8 pS, Na+- and K+- selective channel could be induced by application of palytoxin. For channel activity, the presence of extracellular Na+ is essential. It is assumed that the Na+, K+-pump molecule is involved in the channel formation. Similarly, it is discussed whether the anionselective channel represents a pore conformation of an electrically silent anion exchanger.

Body fluid distribution was measured in three donkeys, fully hydrated, following dehydration and after being rapidly rehydrated. In twenty other donkeys that were slaughtered to supply food for predators iri a safari zoo, the water content in the different compartments of the gastrointestinal tract (GIT) was assessed. Prior to being slaughtered, four of the animals were fully hydrated, four dehydrated and 12 dehydrated, rehydrated and then slaughtered and examined, four at 1, four at 3 and four at 5 hours following drinking. When the body mass of dehydrated donkeys dropped to 75.4± 2.4% of their initial value, total body water of the animals (HTO space), extracellular volume (SCN space) and plasma volume (EB space) were reduced to 76.6 ± 5.3%, 80.9 ± 10.6% and 73.2 ± 8.3% of their initial values, respectively. The amount of water retained in the GIT of the fully hydrated donkeys amounted to 15.9 ± 3.4 1, 19% of total body water. In the dehydrated donkeys it was only 7.4± 1.3 1. The calculated total intracellular volume in the dehydrated donkeys was only 14% lower than in the fully hydrated animals. When drinking was allowed, dehydrated donkeys consumed 17.6 ± 2.4 1 of water. The increase in the water content in the gut of newly rehydrated donkeys matched this volume, 80% of which was retained in the hind gut. During the five hours after drinking, only slow and moderate changes in the volume of the hind gut were recorded. Changes in plasma volume were also suppressed. It is suggested that the hind gut of the donkey, similar to the rumen of goats and sheep, plays a role as a water reservoir that helps maintain the osmotic stability of the body.

Clinical success in prevention of sudden cardiac death has been poor. New approaches to prevention of ventricular fibrillation (VF), one of the main causes of sudden cardiac death, are clearly needed. In the present article we have reviewed some of our own data which support the notion that VF may be prevented by manipulation of chloride homeostasis /1,2/. Our studies have revealed a novel approach to VF suppression via alteration of sarcolemmal membrane resistance.

Point-of-care testing (POCT) refers to decentralized testing done using complex but compact, portable devices that can be done near the site at the patient's bedside. These enable quick diagnosis and timely intervention because turnaround time (TAT) decreases with these devices. They can also be operated by non-medical personnel and patients with minimum expertise as these devices are easy to handle and interpret. This increases patient awareness regarding their diseases and benefits doctors in giving more patient-centered care. POCT devices require minimum setup and can be utilized even in remote places. The present review focuses on POCT devices employed specifically in clinical biochemistry, e.g., glucose, HbA1c, cardiac biomarkers, fertility tests, hematological analysis, electrolytes, enzymes, urine dipstick tests, etc. This introductory review delves into comprehending the fundamentals of POCT technologies, their guidelines, applications, advantages, and disadvantages. It covers a broad overview of the tests done and the samples required to process these tests. It also compares the pros and cons of POCT devices over centralized laboratory testing. The review also aims to emphasize the relevance of its use in today's era, current trends regarding POCT in urban and rural setups, challenges faced in the field during its implementation, and the potential areas of improvement in the future. However, it is advisable to seek references for more detailed and critical information regarding all the specific topics given in this review article.