Gas jet transection of liver parenchima. Experimental research.

BACKGROUND: There is a great variety of liver parenchyma transection techniques. The objective of this research lies in developing a new method of liver transection and comparing it to the existing ones. METHODS: The original gas jet transection method of biological tissues and the apparatus for its realization "Pneumojet" were developed in our institute. Efficiency comparison of gas jet,water jet, ultrasonic methods of liver transection and clamp crushing technique were carried out on 24 mini-pigs. We did not use Pringle manoeuver. RESULTS: The mean blood loss was the smallest in the group of animals that had a gas jet transection (3.5+-0.15 ml/cm²) and the highest in the clamp crushing technique group (5.5+-0.46ml/cm²). Indicators present statistically authentic differences(p 0.001). The transection speed was the highest in the Clamp crushing technique group (2.9+-0.25 cm²/min) and was credibly higher than in the gas jet (2.4+-0.16 cm²/min), ultrasonic(2.4+-0.13 cm²/min) and water jet (2.5+-0.14 cm²/min) transection groups. Compared to the water jet and ultrasonic methods of liver transection the original method does not have statistically reliable distinctions on the basic indexes of work. CONCLUSIONS: The research conducted proves high efficiency and safety of the gas jet transection method. Gas jet transection,therefore, can be recommended for further improvement and clinical application.

[The role of ischemical preconditioning in the development of ischemia-reperfusion hepatic injury in experiment].

The optimal regimen of preliminary ischemic preparation, in which the vessels occlusion causes minimal pathohistological hepatic changes without inhibition of its regeneration capacities, was studied in experiment. The ischemic-reperfusional damage of liver, using hepatoduodenal ligament crossclamping in various regimens, was modeled on 40 rabbits in a randomized experimental investigation. Morphological investigations of the animals liver fragments, taken immediately after ligament crossclamping and on the third postoperative day, were performed. There was established, that severity and reversibility of the hepatic tissue affection have differed, depending on the ischemia duration and reperfusion period. The vessels occlusion regimen with preliminary ischemic preparation was the most safe for hepatic tissue, without rude structural injuries and functional disorders, permitting to recommend it for clinical application as the optimal one while performance of hepatic resection in combination with afferent vascular exclusion.

[Hypodynamia and spontaneous venous thromboses].

Data on the prevalence of hypodynamia among individuals with the first and second episodes of spontaneous venous thrombosis in a population sample of Moscow residents are compared. It is stressed that changes in behavioral stereotype, which determine the reduction of physical activity level before the first episode, are significant for the risk of rethrombosis. Besides, the authors discuss a range of questions concerning terminology of low physical activity, distinguishing the reasons for hypodynamia, and evaluation of existing questionnaires for measuring the levels of physical activity.

[Promoters of genes MTHFR from patients with hyperhomocysteinemia and PTEN from patients with malignant and benign endometrial and ovarian tumors].

Mutational changes in the promoter regions of MTHFR genes from patients with hyperhomocysteinemia and PTEN genes from patients with endometrial and ovarian tumors were studied. An increased level of homocysteine was found in a part of the patients with a heterozygous C677T mutation in the MTHFR gene, although a moderate hyperhomocysteinemia is usually associated with homozygous mutation. We hypothesized that, in this case, the allele lacking the C677T mutation may be inactivated by the promoter mutation. The sequencing of both DNA strands of the minimal promoter region of the MTHFR gene in ten patients did not reveal any mutation, which implied another mechanism of the development of hyperhomocysteinemia in these patients. A PCR analysis of the minimal promoter region of the tumor suppressor PTEN in the presence of 2-pyrrolidone in 101 patients from Moscow clinics revealed changes in it in patients with endometrial (56%) or ovarian (29%) cancer, as well as in patients with endometrial hyperplasia and benign ovarian tumors (34.6 and 29%, respectively). It was presumed that the found PTEN gene promoters may arise from epigenetic alterations (erroneous methylation) or may (more rarely) be induced by mutations. As a result of the studies, new molecular markers associated with endometrial and ovarian tumors were revealed and a simple and effective method of detection of these markers was developed.

[The prognostic value of thrombus precursor protein in the assessment of the probability for venous thrombosis recurrence after the completion of anticoagulatory therapy with warfarin].

The article contains data on venous thrombosis (VT) recurrence rate in patients with the first episode of thrombus formation after the completion of one-year therapy with warfarin. The investigation included study of the prognostic value of intravascular coagulation marker (thrombus precursor protein --TPP) for the risk of venous retrombosis. The study showed that a high TPP level at the end of standard therapy course with warfarin in patients who had the first episode of spontaneous venous thrombosis is a significant indicator of a possible thrombosis recurrence during the nearest two tears after treatment with anticoagulants.

[Use of fragmin in program hemodialysis of patients with terminal chronic renal failure].

The subjects of the study were 60 patients at the end stage of chronic renal failure of various origins, who were on program hemodialysis (PHD) in Dialysis Center of City hospital #20. The main group consisted of 25 patients, who were administered fragmin (Pfizer, USA), a low-molecular heparin, for hypocoagulation during the procedure of hemodialysis. The drug was administered in a bolus dose of 5000 aXa ICU into the arterial line after connecting it to a fistula needle. The control group (35 patients) received unfranctionated heparin (UFH) in a conventional way (a bolus of 2000 to 2500 IU before the beginning of the procedure, followed by 1200 to 1500 IU/h in a continuous infusion, stopped 1 hour prior to the end of the dialysis). The following parameters were measured at the beginning and the end of the procedure: the number of thrombocytes, hemoglobin and hematocrit levels, activated partial thromboplastin time, activated coagulation time, antithrombin III level, and anti-Xa factor activity. Standard regimen of UFH administration allowed satisfactory hypocoagulation, but the necessary dose was hard to select. A bolus dose of fragmin led to adequate hypocoagulation in all the patients: there were no fibrin or blood clots in the lines or the dialyzer, or hemorrhage from the sites of puncture after the procedure. Anti-Xa-factor activity grew after a bolus injection of fragmin. By the end of the procedure the inhibitory activity of fragmin towards Xa-factor remained at the level of 0.44 +/- 0.7 IU/ml. The results show that a single dose of fragmin is effective and safe during a standard procedure of hemodialysis lasting up to 5 hours.

[The activity of ethanol- and aldehyde-oxidizing enzymes of the brain in ethanol intoxication]. / Aktivnost' étanol- i al'degidokisliaiushchikh fermetov golovnogo mozga pri otravlenii étilovym spirtom.

The distributed activity of alcohol dehydrogenase (ADG) and aldehyde dehydrogenase (AldDG) was histochemically studied in neurons of locus coeruleus, nuclei of raphe, substantia nigra and in cerebellar cortex in death or intoxication of ethanol (IE). The enzymatic activity was found to be changing depending on whether there was IE or not. Both higher ADG and lower AldDG were registered in the examined brain sections, which differ by mediatory structure of the neuronic centers. The detected regularities can be used within the forensic medical diagnosis of IE.

[Characteristics of the silver-stained nucleoli of tumor cells from the pleural fluid of lung cancer patients]. / Kharakteristika okrashennykh serebrom iadryshek opukholevykh kletok iz plevral'noi zhidkosti bol'nykh rakom legkikh.

Tumor cell nucleoli obtained from pleural effusions of 26 patients with different morphologic types of lung cancer were evaluated by silver staining. Distinct heterogeneity of tumor cell populations, with regard to the number of nucleoli as well as their functional activity in respect to ribosomal RNA synthesis, were shown to be the most common feature of all the tumors studied, regardless of their morphologic variants. One likely cause of heterogeneity in Ag nucleolar organized region (NOR) pattern of tumor cells may be due to chromosomal losses and gains from the karyotypes of acrocentric chromosomes with active NORs. Another possible cause for heterogeneity in nucleolar activity might be due to different reactions of tumor cells towards some humoral and cellular factors of pleural fluid including T-lymphocytes.

The activity of nucleolar organizer regions of human bone marrow cells studied with silver staining. II. Acute leukemia.

The activity of nucleolar organizer regions (NOR) in chromosomes and interphase nuclei of bone marrow cells from 11 adult patients with acute lymphoblastic leukemia (ALL), 35 patients with acute nonlymphoblastic leukemia (ANLL), and eight healthy donors has been studied with silver nitrate staining. PHA-stimulated lymphocytes of the same individuals were used as standards of the maximum silver-staining patterns for each person. In 90% of patients with acute leukemia the average number of Ag+NOR in metaphases was lower when compared with that of PHA-stimulated lymphocytes. A variable expression of NOR was observed within the cell population and between individual patients. The populations tested showed high heterogeneity in relation to the content of Ag-negative mitoses. Ag+NOR per metaphase and the content of Ag-negative mitoses in bone marrow did not differ between patients with ALL and ANLL. Differences in the staining pattern in leukemic cells are discussed.

[Nucleolar organizer activity of normal and leukemic cells in human bone marrow]. / Aktivnost' iadryshkovykh organizatorov normal'nykh i leikoznykh kletok kostnogo mozga cheloveka.

The nucleolus organizer activity of bone marrow cell chromosomes has been studied by silver staining (Howell, Black, 1980) for 6 healthy donors, 24 patients with acute leukemia, and 17 patients with chronic myelocytic leukemia, including 6 cases of blast crisis. In respect to the nucleolus organizer silver staining pattern, bone marrow cells of donors and of patients with leukemias appeared to be more heterogeneous than PHA-stimulated lymphocytes of the same individuals. The average numbers of Ag-stained nucleolus organizers per metaphase in donors (5.2 +/- 0.22), patients with chronic phases (4.9 +/- 0.30), and patients with blast crisis of myelocytic leukemia (5.3 +/- 0.37), and in those with acute leukemia (5.2 +/- 0.46) were lower than those in PHA-stimulated lymphocytes of the same individuals; a great part of bone marrow cell mitoses (from 19 up to 46%) being Ag-negative in all the above groups. A conclusion is made that the heterogeneity in silver staining of the nucleolus organizers in bone marrow cells is due mostly to differences in their mitotic cell maturity degrees. Prospects of employment of silver staining of nucleolus organizers in cells for clinical purposes are discussed.