The mechanisms of the porphyrin conformation of normal blood hemoglobin and in pathology]

The spectra of resonance Raman scattering of blood in norm and under pathology (myocardial infarction and sepsis), as well after artificial hemotransfusion or UV photomodification have been studied. It has been shown that under heart pathology the structure of hemoglobin porphyrin macrocycle of erythrocytes changes, the size of porphyrin "nucleus" increases. The opposite conditions are observed at blood sepsis. It has been found that the traditional methods in tissue restoration, hemotransfusion and UV photomodification of blood don't result in complete restoration of hemoporphyrin molecule.     

Phenomenon of indirect isoserological incompatibility in experimental transfusion research and its clinical significance

It has been established in experiments on dogs exposed to blood transfusions that if the animals are screened according to the cross-matching testing system and show as a result the lack of red blood cell agglutination, this does not provide evidence in favour of their complete isoserological compatibility. To confirm whether the animals are compatible, it is required to carry out 7 to 8 tests with other species. If the tests reveal red blood cell agglutination, blood transfusion is characterized by demonstrable isoserological incompatibility and the recipient dies. If the cross-matching with the other animals of the group is accompanied by red blood cell agglutination but the latter is absent in the testing of a particular animal pair, such a condition is designated as "indirect" incompatibility, since hemotransfusion in this animal pair is characterized by the manifestations of incompatibility. However, it is not so pronounced and the recipient can be saved by intensive care. The authors conclude that isoserological incompatibility has different grades of intensity and offer methods for the screening of animals for simulation of graver and facilitated grades of incompatibility. It is assumed that the clinical transfusiology also has grades of the severity of hemotransfusion-induced conflicts, particularly in cardiosurgery. The use of large amounts of donor's blood for extracorporeal circulation and making for large blood losses is very likely to entail isoserological incompatibility cases which may remain unrecognized because of the gravity of surgical intervention, provoking at the same time the postoperative acute heart failure.     

A Four-Compartment Metabolomics Analysis of the Liver,Muscle, Serum,and Urine Response to Polytrauma with Hemorrhagic Shock following Carbohydrate Prefeed

Objective

Hemorrhagic shock accompanied by injury represents a major physiologic stress. Fasted animals are often used to study hemorrhagic shock (with injury). A fasted state is not guaranteed in the general human population. The objective of this study was to determine if fed animals would exhibit a different metabolic profile in response to hemorrhagic shock with trauma when compared to fasted animals.

Methods

Proton (1H) NMR spectroscopy was used to determine concentrations of metabolites from four different compartments (liver, muscle, serum, urine) taken at defined time points throughout shock/injury and resuscitation. PLS-DA was performed and VIP lists established for baseline, shock and resuscitation (10 metabolites for each compartment at each time interval) on metabolomics data from surviving animals.

Results

Fed status prior to the occurrence of hemorrhagic shock with injury alters the metabolic course of this trauma and potentially affects mortality. The death rate for CPF animals is higher than FS animals (47 vs 28%). The majority of deaths occur post-resuscitation suggesting reperfusion injury. The metabolomics response to shock reflects priorities evident at baseline. FS animals raise the baseline degree of proteolysis to provide additional amino acids for energy production while CPF animals rely on both glucose and, to a lesser extent, amino acids. During early resuscitation levels of metabolites associated with energy production drop, suggesting diminished demand.

Conclusions

Feeding status prior to the occurrence of hemorrhagic shock with injury alters the metabolic course of this trauma and potentially affects mortality. The response to shock reflects metabolic priorities at baseline.     

Histochemical investigations on phosphorylase, branching enzyme and glycogen in guinea pig livers in experimental anaphylactic and histaminic shock

The investigations have been carried out on 116 guinea pigs divided in three groups: the control (first group), the experimental group with animals after acute anaphylactic shock (second group), the animals after histaminic shock (third group). The animals of the experimental (second) group were sensitized with 25% egg white suspension in 0.9% NaCl applied subcutaneously. The same animals were exposed to the action of the antigen in aerosol (second group). The healthy animals were exposed to the action of 1% solution of dihydrochloride histamine (third group). In acute anaphylactic shock a decrease of histoenzymatic activity of phosphorylase A and branching enzyme in liver parenchyma was observed. It has been concluded that in anaphylactic shock there occurred disturbances in the function of the phosphorylase A--branching enzyme system. In histaminic shock the phosphorylase reaction becomes intensified in numerous liver cells. This is possible because the exogenic histamine may lead to the activation of the enzymatic system under studies.     

Role of the biological activity of serotonin in the production of the "shock lung" syndrome]

The influence of the serotin biological activity on forming the "shock" lung syndrome was revealed in experiments on rats. Tachyhyperpnea with predominance of functional emphysema and a small number of atelectic tissue areas were observed in the animals with traumatic "shock" during the serotonin hypersecretion. Tachyhypopnea with a significant predominance of atelectiv areas was seen during the serotonin hypoproduction.     

Change in the contractile activity of the rabbit myocardium as a result of burn shock of different duration]

Experiments were carried out on the papillary muscles prepared from the rabbit heart 10, 60 or 180 minutes after exposure of the animals to thermal burn. Isometric tension in the changing stimulation frequency of the preparation (the range being 0.1-2.0 Hz) and in post-stimulating potentiation was recorded. It was shown that the disturbance degree of the myocardial contractile activity caused by the burn rose depending on increased shock duration. It was evidenced by the following findings: in all the papillary muscles prepared 3 hours after burn and in 50% of the preparations taken one hour after the injury the "biphasic" dependence frequency power (F-P) peculiar to healthy myocardium changed to "monophasic" one (contraction amplitude progressively decreased on the frequency growing), and poststimulating potentiation, absent in the normal myocardium state, appeared. Within 10-minute shock duration only several preparations revealed poststimulating potentiation, F-P changes being absent. Normal rhythmoinotropic relationships in the myocardium restored under the influence of two-fol increase of (Ca2+)o or under prolonged (3-4 hours) perfusion of the preparation with normal Tyrode's solution. The changes observed in the myocardium rhythmoinotropic relationships produced by the burn shock were similar to those occurred as a result of the calcium canals block by the compound D-600.     

Effect of the variable magnetic field of the extremely low frequency on metabolic processes in the liver of animals with various individual and typological characteristics

The effect of alternating magnetic field (8 Hz, 5 microT) on lipid peroxidation, thiol-disulfide exchange, the antioxidant system, and energy metabolism in liver of animals was studied. It was found that metabolic changes caused by the application of magnetic field vary in animals with different behavior in the "open field". Statistically significant changes in the activity of some enzymes involved in the antioxidant system and thiol-disulfide exchange were revealed.     

Attenuation of sepsis-induced apoptosis by heat shock pretreatment in rats

Apoptosis is a process by which cells undergo a form of non-necrotic cellular suicide. Although it is a programmed process, apoptosis can be induced by various stressors. During sepsis, apoptosis has been regarded as an important cause of cell death in the immune system, leading to unresponsiveness to treatment. This study was designed to investigate how prior heat shock induction can influence the rate of apoptosis in animals that have experienced sepsis. Sprague-Dawley rats were used, and experimental sepsis was induced by cecal ligation and puncture (CLP). Animals in the heated group were anesthetized and received heat shock by whole-body hyperthermia. They were sacrificed 9 h and 18 h after CLP as early and late sepsis, respectively. Apoptosis was evaluated by "DNA ladder" detection in agarose electrophoresis and Tdt-mediated dUTP nick end-labeling (TUNEL) assay. Hsp72 was detected by Western blot analysis. The results showed that the DNA ladder was detected most clearly in the thymus at the late phase of sepsis with time course dependence, while it showed less clearly in heat shock treated animals. Histopathological study by TUNEL assay obtained similar results in the thymus, where the cortex was more susceptible to apoptosis than the medulla. The Western blot analysis showed that the heat shock induced Hsp72 concomitant with an increase in Bcl-2:Bax ratio. In conclusion, heat shock pretreatment prevents rats from sepsis-induced apoptosis that may account for the better outcome of experimental sepsis. An increase in the Bcl-2:Bax ratio may in part explain the molecular mechanism of the effect of heat shock pretreatment.     

Toxic shock syndrome toxin 1 (TSST-1) production by staphylococci isolated from goats and presence of specific antibodies to TSST-1 in serum and milk.

The ability of staphylococcal strains isolated from different anatomical sites in 133 healthy goats to produce toxic shock syndrome toxin 1 (TSST-1) and the presence of antibodies to this toxin in serum and milk were studied. The enzyme-linked immunosorbent assay method was used to detect both the toxin and the presence of antibodies. Of a total of 342 staphylococcal strains studied, 86 (25.2%) were found to produce TSST-1. Specific antibodies to TSST-1 were found in the serum of 57 (42.9%) of the animals studied and the milk of 63 (47.4%) of the animals. These results suggest that goats are frequently in contact with staphylococci that produce TSST-1, a toxin usually associated with Staphylococcus aureus strains isolated from cases of toxic shock syndrome in humans.     

Toxic shock syndrome toxin 1 (TSST-1) production by staphylococci isolated from goats and presence of specific antibodies to TSST-1 in serum and milk

The ability of staphylococcal strains isolated from different anatomical sites in 133 healthy goats to produce toxic shock syndrome toxin 1 (TSST-1) and the presence of antibodies to this toxin in serum and milk were studied. The enzyme-linked immunosorbent assay method was used to detect both the toxin and the presence of antibodies. Of a total of 342 staphylococcal strains studied, 86 (25.2%) were found to produce TSST-1. Specific antibodies to TSST-1 were found in the serum of 57 (42.9%) of the animals studied and the milk of 63 (47.4%) of the animals. These results suggest that goats are frequently in contact with staphylococci that produce TSST-1, a toxin usually associated with Staphylococcus aureus strains isolated from cases of toxic shock syndrome in humans.     

Heart Rate Variability Analysis in an Experimental Model of Hemorrhagic Shock and Resuscitation in Pigs

Background

The analysis of heart rate variability (HRV) has been shown as a promising non-invasive technique for assessing the cardiac autonomic modulation in trauma. The aim of this study was to evaluate HRV during hemorrhagic shock and fluid resuscitation, comparing to traditional hemodynamic and metabolic parameters.

Methods

Twenty anesthetized and mechanically ventilated pigs were submitted to hemorrhagic shock (60% of estimated blood volume) and evaluated for 60 minutes without fluid replacement. Surviving animals were treated with Ringer solution and evaluated for an additional period of 180 minutes. HRV metrics (time and frequency domain) as well as hemodynamic and metabolic parameters were evaluated in survivors and non-survivors animals.

Results

Seven of the 20 animals died during hemorrhage and initial fluid resuscitation. All animals presented an increase in time-domain HRV measures during haemorrhage and fluid resuscitation restored baseline values. Although not significantly, normalized low-frequency and LF/HF ratio decreased during early stages of haemorrhage, recovering baseline values later during hemorrhagic shock, and increased after fluid resuscitation. Non-surviving animals presented significantly lower mean arterial pressure (43±7vs57±9 mmHg, P<0.05) and cardiac index (1.7±0.2vs2.6±0.5 L/min/m², P<0.05), and higher levels of plasma lactate (7.2±2.4vs3.7±1.4 mmol/L, P<0.05), base excess (-6.8±3.3vs-2.3±2.8 mmol/L, P<0.05) and potassium (5.3±0.6vs4.2±0.3 mmol/L, P<0.05) at 30 minutes after hemorrhagic shock compared with surviving animals.

Conclusions

The HRV increased early during hemorrhage but none of the evaluated HRV metrics was able to discriminate survivors from non-survivors during hemorrhagic shock. Moreover, metabolic and hemodynamic variables were more reliable to reflect hemorrhagic shock severity than HRV metrics.     

Assessing hemorrhagic shock: Feasibility of using an ultracompact photoacoustic microscope

Hemorrhagic shock, as an important clinical issue, is regarding as a critical disease with a high mortality rate. Unfortunately, existing clinical technologies are inaccessible to assess the hemorrhagic shock via hemodynamics in microcirculation. Here, we propose an ultracompact photoacoustic microscope to assess hemorrhagic shock using a rat model and demonstrate its clinical feasibility by visualizing buccal microcirculation of healthy volunteers. Both functional and morphological features of the microvascular network including concentration of total hemoglobin (C_HbT), number of blood vessels (VN), small vascular density (SVD) and vascular diameter (VD) were derived to assess the microvascular hemodynamics of different organs. Animal studies show the feasibility of the proposed tool to assess and stage the hemorrhagic shock via microcirculation. in vivo oral imaging of healthy volunteers indicates the translational possibility of this technique for clinical evaluation of hemorrhagic shock.      

Effect of the intra-aortic administration of prostaglandin E2 on kidney functions in acute kidney failure of blood transfusion origin

It has been shown that intraaortal prostaglandin E2 injection to dogs arrested acute renal failure of hemotransfusion genesis, which was expressed in normalization of minute and diurnal diuresis, glomerular filtration rate, tubular reabsorption, maximal tubular secretion, renal plasma flow, urea and creatinine levels. The data obtained serve as an experimental basis for prostaglandin E2 application in the treatment of acute renal failure.     

Neuroendocrine mechanisms of participation of the raphe nuclei in the development of hypertensive reactions in emotional stress

The experiments on cats and rabbits have studied electroencephalographic, endocrine and blood pressure responses to stress (5-hour immobilization with electrical foot shock) before and after coagulation of the midbrain nuclei raphe. Blood pressure and adrenal responses in advanced (4-hour) stress were elevated in intact animals, the responses attenuating after coagulation of the nuclei raphe. Background bioelectrical activity of the midbrain reticular formation and hypothalamus was found to be activated in the operated animals. Stress was followed by the reduction in bioelectrical changes of the above subcortical structures with the parallel development of "burst" activity in the dorsal hippocamp.     

Beneficial effects of pituitary grafts under the renal capsule on behavior of dwarf mutant mice

The effects of pituitary grafts under the kidney capsule were studied in "dwarf" mutant mice which because of anterohypophyseal deficiency, exhibit dwarfism, sterility and important behavioral deficits. One month after grafting, the body weight was 120% in the grafted mutants while only 11 and 8% respectively in normal and sham-grafted controls. At the behavioral level, the animals were examined on 2 tasks: spontaneous alteration in a T maze and passive avoidance (step-through). Grafted mutant mice, as well as sham-grafted normal controls, were able to alternate successfully, while the sham-grafted "dwarf" mice persevered. In the step-through task, grafted animals as well as sham-grafted normal mice, avoided, entering the dark compartment, 24 h after the shock trial. On contrast, sham-grafted dwarf mice did not show passive avoidance of the shock. According to the literature, pituitary grafts under the kidney capsule secrete high levels of prolactin and very little, if any, of other pituitary hormones. It is not yet clear how the presence of only prolactin can explain the body weight and the maintenance of the behaviors we investigated.     

A Technique for Performing Electrical Impedance Myography in the Mouse Hind Limb: Data in Normal and ALS SOD1 G93A Animals

Objective

To test a method for performing electrical impedance myography (EIM) in the mouse hind limb for the assessment of disease status in neuromuscular disease models.

Methods

An impedance measuring device consisting of a frame with electrodes embedded within an acrylic head was developed. The head was rotatable such that data longitudinal and transverse to the major muscle fiber direction could be obtained. EIM measurements were made with this device on 16 healthy mice and 14 amyotrophic lateral sclerosis (ALS) animals. Repeatability was assessed in both groups.

Results

The technique was easy to perform and provided good repeatability in both healthy and ALS animals, with intra-session repeatability (mean ± SEM) of 5% ±1% and 12% ±2%, respectively. Significant differences between healthy and ALS animals were also identified (e.g., longitudinal mean 50 kHz phase was 18±0.6° for the healthy animals and 14±1.0° for the ALS animals, p = 0.0025).

Conclusions

With this simple device, the EIM data obtained is highly repeatable and can differentiate healthy from ALS animals.

Significance

EIM can now be applied to mouse models of neuromuscular disease to assess disease status and the effects of therapy.     

Lipopolysaccharide (LPS)-induced septic shock causes profound changes in myocardial energy metabolites in pigs

Introduction

Energy deficiency is a cause for myocardial dysfunction during septic shock. In rodents, septic shock decreases the oxidation of long-chain fatty acids and glucose in the myocardium causing energy deficiency. However, the effect of septic shock on myocardial energy metabolites in large animals and human is unknown.

Objectives

Investigate the effects of septic shock on myocardial energy metabolites in domestic pigs.

Methods

Seventeen female pigs divided into control and lipopolysaccharide (LPS)-induced septic shock groups. Myocardial metabolites were analyzed ex vivo by ¹H nuclear magnetic resonance spectroscopy and liquid chromatography-tandem mass spectrometry. Gene and protein expression analysis were analyzed by real-time PCR and western blot.

Results

Septic shock was associated with an increase in myocardial levels of short- and medium-chain acylcarnitines, lactate, alanine, and pyruvate dehydrogenase kinase 4 gene expression. COX-2 and prostaglandin E4 receptor gene expression also increased in the septic myocardium, although the only elevated eicosanoid in the septic animals was thromboxane B2. Myocardial levels of niacin, taurine, glutamate, glutamine, and glutathione were higher, and hypoxanthine levels lower in septic pigs than controls.

Conclusions

In pigs, septic shock induced by LPS caused myocardial changes directed to decrease the oxidation of medium- and short-chain fatty acid without an effect on long-chain fatty acid oxidation. The increase in myocardial levels of lactate, alanine, and pyruvate dehydrogenase kinase 4 gene expression suggest that septic shock decreases pyruvate dehydrogenase complex activity and glucose oxidation. Homeostasis of niacin, taurine, glutamate, glutamine, glutathione, hypoxanthine and thromboxane B2 is also affected in the septic myocardium.

     

The physiological changes of cumulative hemorrhagic shock in conscious rats

Summary Hemorrhagic shock is a common cause of death in emergency rooms. Current animal models of hemorrhage encounter a major problem that the volume and the rate of blood loss cannot be controlled. In addition, the use of anesthesia obscures physiological responses. Our experiments were designed to establish an animal model based on the clinical situation for studying hemorrhagic shock. Hemorrhagic shock was induced by withdrawing blood from a femoral arterial catheter. The blood volume withdrawn was 40% of the total blood volume for group 1 and 30% for group 2 and 3. Group 3 was anesthetized with sodium pentobarbital (25 mg/kg, i.v.) at the beginning of blood withdrawal. Our data showed that the survival rate was 87.5% at 48 h in the conscious group and 0% at 9 h in anesthetic group after hemorrhage. The levels of mean arterial pressure, heart rate, white blood count, TNF-, IL1-, CPK, and LDH after blood withdrawal in the anesthetic group were generally lower than those in conscious groups. These results indicated that anesthetics significantly affected the physiology of experimental animals. The conscious, unrestrained and cumulative volume-controlled hemorrhagic shock model was a good experimental model to investigate the physical phenomenon without anesthetic interfernce.     

Dissipation of Excess Energy in Mehler-Peroxidase Reaction in Rumex Leaves During Salt Shock

By measurement of gas exchange and chlorophyll fluorescence, the effects of salt shock on photosynthesis and the mechanisms to protect photosynthetic machinery against photodamage during salt shock were investigated in leaves of Rumex seedlings. Salt shock induced significant decrease in photosynthesis both in 21 and 2 % O₂. In 21 % O₂, quantum yield of photosystem 2 (PS2) electron transport (_PS2) decreased slightly and q_P remained constant, suggesting that the excitation pressure on PS2 did not increase during salt shock. In 2 % O₂, however, both _PS2 and q_P decreased significantly, suggesting that the excitation pressure on PS2 increased during salt shock. NPQ increased slightly in 21 % O₂ whereas it increased significantly in 2 % O₂. The data demonstrated that during salt shock a considerable electron flow was allocated to oxygen reduction in the Mehler-peroxidase reaction (MPR). Under high irradiance and in the presence of saturating CO₂, the susceptibility of PS2 to photoinhibition in salt-shocked leaves was increased when the electron flow to oxygen in MPR was inhibited in 2 % O₂. Hence, MPR is important in photoprotection of Rumex seedlings during salt shock.