Abdominal perfusion pressure and coronary arterial perfusion pressure in patients undergoing coronary artery bypass graft surgery.

Abdominal perfusion pressure (APP) is defined as the difference between the mean arterial pressure and the intra-abdominal pressure (IAP). IAP elevation results in various side effects, including a decrease in coronary arterial perfusion pressure (CoPP). The present study analyzed the relationship between APP and CoPP in patients undergoing extracorporeal circulation (ECC). The patient population selected for the present study comprised 45 adult patients with a mean (+/- SD) age of 65.9+/-7.21 years (range 42 to 80 years), undergoing coronary artery bypass grafting with ECC and normovolemic hemodilution under general anesthesia. CoPP was measured as the difference between mean arterial pressure and pulmonary capillary wedge pressure. APP and CoPP were measured at seven time points (TPs): before surgery after the induction of anesthesia (TP1), during internal mammary artery preparation (TP2), 10 min after the heart-lung machine disconnection (TP3), after completion of the procedure but before sending the patient to the postoperative intensive care unit (TP4), 1 h after surgery (TP5), 6 h after surgery (TP6) and 18 h after the procedure (TP7). TP1 was considered to be the baseline value. IAP increased from TP3 to TP7; APP decreased at TP3 and TP4; there were no significant changes in CoPP. Significant correlations between APP and CoPP were observed at all TPs. Moreover, IAP correlated with CoPP at TP2 and TP4. Additionally, there was a strong overall correlation between APP and CoPP (P<0.001, r=0.9598). The present study arrived at two major conclusions: that ECC resulted in IAP elevation and that APP was strongly correlated with CoPP.

The efficiency of magnesium supplementation in patients undergoing cardiopulmonary bypass: changes in serum magnesium concentrations and atrial fibrillation episodes.

UNLABELLED: The purpose of the study was to analyse the effects of different forms of magnesium supplementation on its serum concentrations and the frequency of atrial fibrillation in patients undergoing coronary artery bypass graft surgery with extracorporeal circulation (ECC). One hundred and twenty adult patients were examined. All of them received intravenous infusions of MgSO4 during surgery and the early postoperative period (18 hours). Moreover, some of them received preoperative Mg supplementation. Therefore, patients were divided into six groups: A) patients, receiving an intravenous infusion 3.33 mg of MgSO4 per min; B) those receiving preoperative, oral Mg supplementation (OPS-Mg) and intravenous 3.33 mg of MgSO4 per min; C) patients receiving intravenous 6.66 mg of MgSO4 per min; D) patients receiving OPS-Mg and 6.66 mg of MgSO4 per min; E) patients receiving intravenous 10 mg of MgSO4 per min; F) those receiving OPS-Mg and 10 mg of MgSO4 per min. Additionally, all patients were divided into three groups: O (patients, who did not receive dopamine or dobutamine infusions), DOP (those receiving dopamine infusions in doses dependent on their clinical state) and DOB (those receiving dobutamine infusions in doses dependent on their clinical state). Total serum Mg concentrations (Mg(t)) were measured at five points: 1) 10 min before anaesthesia; 2) 10 min after ECC; 3) 10 min after surgery, 4) in the morning of postoperative day 1, 5) in the morning of postoperative day 2. The data were analyzed statistically; values at the first measurement points were considered as baseline. In group A, Mg(t) decreased at time points 2, 3, 4. Similar changes were observed in group B, however, in both groups Mg(t) returned to the baseline value at time point 5. In groups C and D, Mg(t) decreased at point 2 and 3, whereas in groups E and F it was increased during all the study period. The changes in Mg(t) were slightly less in patients receiving OPS-Mg, these patients had a significantly higher Mg(t) at time point 1. Mg(t) decreased in the O, DOP and DOB groups at measurement points 2 and 3. Moreover, the lowest Mg(t) was observed in the DOP group. Atrial fibrillation (AF) was noted in 33 patients (27.5%). The highest percentage of patients with AF during the early postoperative days was observed in groups A and B (45%). In groups C, D, E and F, AF was detected in 25%, 20%, 20% and 10% of patients, respectively. The incidence of AF was significantly higher in groups A and B compared to the other groups. Moreover, episodes of AF were rarer in patients receiving preoperative, oral Mg supplementation. CONCLUSIONS: 1) ECC resulted in a decrease in Mg(t); 2) Mg infusion at the dose of 3.33 mg/min had little effect for the prevention of postoperative AF; 3) the infusion of 10 mg/min of MgSO4 maintained the level of Mg(t) during CABG and most effectively reduced AF; 4) OPS-Mg played a beneficial role in Mg(t) disturbances during CABG; 5) dopamine caused the most severe disturbances in serum Mg(t) concentration.

Histomorphology of renal corpuscles of kidney of experimental animals after Cladribine (2-CdA) administration.

The renal corpuscles of the kidney of white Wistar rats was examined. The animals were given Cladribine (2-CdA) subcutaneously at the dosages of 0.07 mg/kg b.w./24 h for 7 days and 0.1 mg/kg b.w./24 h for 6 days in 3 courses with 5 weeks' break between each. The animals were killed in each instance, 24 hours after the last dose of the drug and 4 weeks after the last dose. The kidney samples were taken for histological and histochemical examination, then stained with hematoxylin and eosin, using the Masson's, PAS, and Feulgen's methods. In all of the groups, changes were observed but the intensity differed, with widening or narrowing of the urinary space, thickening of the basement membrane of the parietal layer of the Bowman's capsule and the basement membrane of capillaries, and density changes in capillary vessels. Hyperaemia in renal glomeruli and in all parenchyma, and infiltrations around the tubules and renal glomeruli, were also observed.

Histomorphology of renal proximal convoluted tubules of kidney of experimental animals after Cladribine (2-CdA) administration.

The proximal convoluted tubules of the kidney of the white Wistar rats were examined. The animals were given Cladribine (2-CdA) sub-cutaneously at the dose: 0.07 mg/kg b.w./24 h for 7 days and 0.1 mg/kg b.w./24 h for 6 days in 3 courses, with 5 weeks' break between each. The animals were killed in each instance 24 hours after the last dose of the drug, and 4 weeks after the last dose. The kidney's samples were taken for histological and histochemical examination and were stained with hematoxylin and eosin, using the Masson's, the PAS's, and the Feulgen's method. In experimental group I, we observed few changes (in comparison to the control group): cells of the epithelium of some of the proximal convoluted tubules were however, puffy. In a few tubules we observed some unknown substance and the lumen of some of these tubules was narrowed. In experimental group II, a few proximal convoluted tubules and their lumen were wider with an unknown substance within. We also observed hydropic degeneration. The brush border of these tubules was a little lower than in control group. In experimental group III, the cells of the epithelium of proximal convoluted tubules rested on a thicker basement membrane, the lumen of most of the proximal convoluted tubules being narrow and filled with some unknown substance. In experimental group IV, the lumen of the tubules was a little wider, and the epithelial cells were smaller than in the control group, thus the lumen of the tubules was wider. In the cytoplasm of epithelial cells we observed numerous PAS(+) granules. The low brush border appeared damaged.

Histological examination of the kidney after experimental administration of MK-801 and dexamethasone.

The aim of the research was histological assessment of the influence of MK-801 (NMDA receptor antagonist) and dexamethasone on the kidney. The experiment was carried out on adult Albino-Swiss mouse males. MK-801 was administered in the dose of 0.3 mg/kg/24 h for 8 days, dexamethasone--in the toxic dose of 120 mg/kg/24 h. Kidney slices stained with hematoxylin and eosin and with PAS method were examined with light microscope. The performed experiments revealed that MK-801 causes morphological changes in the shape of slight narrowing of the urinary spaces in renal corpuscles and narrowing of the lumen of the proximal convoluted tubules and dexamethasone administered in toxic doses causes dilatation of these spaces with kidney's hyperemia. MK-801 intensifies morphological changes of the kidney induced by toxic doses of dexamethasone.

Investigations of ultrastructure of damaged and regenerated skeletal muscle fibers.

Our investigations concerned the head of the parietal part of quadriceps femoris, and we based our investigation on observations of the ultrastructure of muscle fibers using an electron microscope. We observed tissue samples taken from patients (10 men) 25-35 years old, who had old damage of knee joint ligament (after about 6 week's immobilization). In the first group, segments of tissue of parietal head of quadriceps femoris were taken inter-operationally from patients in whom there was found old damage of knee joint ligament. The second group was of tissue segments of this muscle after surgical repair of knee and rehabilitation, which consisted in power training using resistance machines. The muscle fiber samples of quadriceps femoris which were taken from patients during the first operation, showed big changes in their ultrastructure. These changes included: myofibrils disintegration; disturbance of regularly arranged striation in sarcomers; dissappearance of Z line. In the sarcoplasm, we observed large vacuolisation, and in the interfibrillar spaces--an accumulation of exudate and morphotic elements of blood outside the capillary vessels. Observations of muscle tissue after regeneration, showed a big improvement in the muscle cell's ultrastructure--the myofibrils were regularly arranged, and the sarcomers striations showed no deviations from normal structure. We also observed a considerable increase in the number of properly formed ultrastructure mitochondria when compared with the first group.

Histological and morphometrical examinations of suprarenal glands in rats after experimental administration of atorvastatin and ethanol.

The experiment was carried out on Wistar rat males weighting about 250 g. Animals from control group I received water and standard granulated fodder ad libitum. Animals from control group II received 20% ethanol instead of water. Animals from experimental group I received Atorvastatin in the dose of 0.28 mg/24h, animals from experimental group II received Atorvastatin in the dose of 2.8 mg/24h, animals from experimental group III received 20% ethanol + Atorvastatin in the dose of 0.28 mg. After 6 weeks the animals were decapitated. H+E staining, PAS method for detection of neutral mucopolysaccharides and Thomas's reaction for detection of lipids were made on 6 micron thick sections. The surface areas of the nuclei sections were assessed in the zona fasciculata. It was stated that ethanol causes strong hyperemia of suprarenal cortex, the high dose of atorvastatin--2.8 mg/24h and small dose of atorvastatin--0.28 mg/24h administered with ethanol cause the decrease of lipid amount in the whole suprarenal cortex and degenerative changes in many cells of the zona fasciculata.

Histological examination of the extrabulbar segment of the optic nerve in experimental animals after administration of Cladribine.

The experiment was carried out on rabbits, females of New Zealand breed, weighting about 3 kg. Rabbits from the experimental group I received Cladribine in the dose corresponding to the schema of the experimental treatment in the hairy cell leukemia and animals from the experimental group II, the dose corresponding to the experimental treatment in multiple sclerosis. The optic nerves were collected for histological examinations in the light microscope. It appeared that administration of Cladribine in the dose corresponding to the therapeutic dose used in therapy of hairy cell leukemia and sclerosis multiplex does not cause evident morphological changes in the extrabulbar segment of the optic nerve on the level of the light microscope.

Influence of the new medicine--2-CDA (Cladribine) on the ultrastructure of the extrabulbar segment of the optic nerve in rabbits of New Zealand breed.

Experiments were carried out on the rabbits of New Zealand breed weighting about 3 kg. Rabbits from the experimental group received Cladribine in the dose of 0.07 mg/kg/24 h each morning subcutaneously for 6 days, three cycles with 5-week intervals. Specimens of the optic nerve were stained according to the Reynold's method and observed in Tesla BS-500 transmission electron microscope. Results achieved from examinations of slides in experimental group indicate that Cladribine administered in the dose corresponding to therapeutic dose used in humans for experimental treatment of sclerosis multiplex does not cause the damage of extrabulbar segment of optic nerve in experimental animals. The achieved results suggest necessity of new research works regarding the eye structures of mesenchymal origin.

Protective effects of ACTH (4-9) in degeneration of hippocampal nerve cells caused by dexamethasone: ultrastructural studies.

The purpose of this research was an assessment of protective action of ACTH (4-9) in dexamethasone-induced neurodegeneneration on the base of ultrastructural examinations of hippocampal neurons in the CA3 region. The experiments were carried out on adult Albino Swiss mouse males. The animals were divided into three groups: control group, experimental group 1-dexamethasone 8 mg/kg/24 h for 28 days, experimental group 2-dexamethasone and ACTH (4-9) 50 micrograms/kg twice a week. Results of our investigations show that ACTH (4-9) prevents neurotoxic influence of dexamethasone and its protective action is connected with the ability to inhibit degenerative processes in neurons having a character of apoptosis.

Immunocytochemical examinations of hippocampal nerve cells after experimental administration of dexamethasone.

The purpose of this research was an assessment of MAP2 immunoreactivity in hippocampal neurons after administration of toxic doses of dexamethasone. Experiments were led on Albino-Swiss mouse males. The obtained results indicate that dexamethasone causes significant decrease of MAP2 immunoreactivity in hippocampal nerve cells of the CA3 region. Our results show damage of neuronal cytoskeleton in this area of the brain.

Neuroprotective effect of ACTH (4-9) in degeneration of hippocampal nerve cells caused by dexamethasone: morphological studies.

The purpose of this research was an assessment of neuroprotective effect of ACTH (4-9) in degenerative changes of nerve cells induced by dexamethasone. Experiments were led on Albino-Swiss mouse males. We examine morphological changes of neurons in the dorsal hippocampus in slides stained with cresyl violet and we performed quantitative analysis of neurodegenerative changes using a computer analyser of histological pictures. Achieved results indicate that ACTH (4-9) shows neuroprotective effect against neurotoxic influence of dexamethasone. This chemical inhibits dexamethasone induced degeneration of hippocampal nerve cells having morphological features characteristic of apoptosis.

Histological changes in the pancreas of white rats after administering cephalexin and ethanol.

The research was conducted on male Wistar rats weighing approximately 200 g. Animals of experimental group I were administered 20% ethyl alcohol for drinking, animals of experimental group II--cephalexin in the dose of 42 mg daily, animals of experimental group III--simultaneously alcohol and cephalexin in the mentioned doses. After 10 days the animals were guillotined and pancreas was taken for research. On paraffin sections 7 mu thick there were carried out H + E stain and PAS reaction aimed at discovering neutral mucopolysaccharides. After administering alcohol there was stated a decrease in the activity of exocrime cells and after administering of cephalexim--an increase in this activity. A simultaneous administration of ethyl alcohol and antibiotic causes trophic changes, which can be noticed as introductory, but at this stage--reversible, degenerative changes.

The influence of Atorvastatin on ultrastructure of rat pancreatic exocrine cells in the course of experimental intoxication with ethanol.

The experiment was carried out on mature Wistar male rats. The animals from experimental group I received Atorvastatin in the dose 0.28 mg/24 h for 3 weeks. Experimental group II received 20% ethanol ad libitum apart from Atorvastatin. Ultrastructural examinations of pancreatic exocrine cells showed the stimulation of secretory processes in cells of animals receiving Atorvastatin and considerable damage of cell organelles in experimental group II, more intense than in the pancreas of control animals which drank ethanol.

Ultrastructural changes of pancreas of white rats after experimental administration of ethanol and cephalexin.

The experiment was carried out on Wistar rat males weighting about 200 g. Animals from experimental group I received 20% ethanol for drinking (ad libitum), animals from experimental group II--cephalexin in the dose of 42 mg/24 h, animals from experimental group III--cephalexin and ethanol in the mentioned doses. After 10 days the animals were decapitated and pancreases were collected for ultrastructural examinations in electron microscope. The performed experiments showed that 10-day administration of ethanol causes mainly the decrease of amount of ribosomes and zymogen granules in pancreatic exocrine cells, whereas cephalexin causes increase of amount of these organelles. Administration of both ethanol and cephalexin causes reversible degenerative changes including distinct decreasing of the number of ribosomes, swelling of many mitochondria and the presence of myelinic structures inside cells.