Restriction polymorphism of the APOB locus in residents of the city of Tomsk

Restriction fragment length polymorphism (RFLP) of the apolipoprotein B locus was investigated in the population of Tomsk. The frequencies of alleles and haplotypes of polymorphic restriction sites XbaI, MspI, and EcoRI were determined. The parameters of linkage disequilibrium and polymorphism information content (PIC) were estimated. Comparative data on various regions of the world are shown.     

Toxoplasma lymphadenitis. Analysis of cytologic and histopathologic criteria and correlation with serologic tests

Fear reactions of rats given bilateral lesions to the septum, hippocampus, or amygdala were compared with those of rats given sham lesions, in 2 animal models of anxiety: the shock-probe burying test and the elevated plus-maze test. Septal lesions produced anxiolytic effects in both tests (i.e., an increase in open-arm activity and a decrease in burying), whereas hippocampal and amygdaloid lesions produced neither of these effects. On the other hand, hippocampal and amygdaloid lesions impaired rats' passive avoidance of the electrified shock-probe, whereas septal lesions did not. These dissociations suggest that limbic structures such as the septum, amygdala, and hippocampus exert parallel but distinct control over different fear reactions.     

Activation of the K-ras oncogene in colorectal neoplasms is associated with decreased apoptosis

BACKGROUND: Recent in vitro data indicate that the oncogenic effects of activated ras genes may be mediated, at least in part, through inhibition of apoptotic cell death. To examine this proposition in vivo, the relationship between mutations of the K-ras gene and the frequency of apoptosis was studied in a series of 69 sporadic colorectal neoplasms (11 adenomas and 58 carcinomas). METHODS: Mutations in codon 12 of K-ras were determined by a single tube, enriched polymerase chain reaction. Apoptotic cells in tumor sections were identified by in situ end-labeling of fragmented DNA, whereas levels of bcl-2 and p53 proteins were determined by immunohistochemistry. RESULTS: Tumors with mutant K-ras had a significantly lower apoptotic index than those with the wild-type allele (P < 0.05). They were also more likely to exhibit positive bcl-2 staining (P < 0.05). Adenomas showed significantly greater bcl-2 positivity than carcinomas (89% and 51%, respectively; P < 0.05). The frequency of apoptosis in these tumors was not related to either bcl-2 positivity or p53 status. CONCLUSIONS: These findings suggest that activation of K-ras in colorectal carcinoma may inhibit apoptosis and thus favor tumor progression. Alternatively, this association may reflect an accumulation of K-ras mutations in cells in which normal apoptotic pathways have been impaired.     

Potentiation of murine MCa-4 carcinoma radioresponse by 9-amino-20(S)-camptothecin

9-Amino-20(S)-camptothecin (9-AC) has demonstrated efficacy against several human cancer xenografts, including cancers of the colon, breast, lung, ovary, and stomach and malignant melanoma, and is currently undergoing Phase I clinical trials. In vitro data indicate that the addition of topoisomerase I inhibitors shortly after irradiation causes conversion of single-strand breaks to double-strand breaks, resulting in synergistic lethality to cultured log-phase or quiescent malignant cells. In our study, the efficacy of 9-AC as a potential radiosensitizing agent in vivo was assessed in C3Hf/Kam female mice bearing 7.6-8-mm MCa-4 mammary tumors implanted i.m. into the right posterior thigh. In one series of experiments to determine the dose dependence of 9-AC, mice were injected twice a week with either 0.5, 1.0, or 2.0 mg/kg 9-AC (total doses of 2, 4, and 8 mg/kg, respectively) either alone or 1 h before irradiation. In a second series of experiments, the schedule dependence of 9-AC was determined by giving a constant total dose of 4 mg/kg 9-AC once (2 mg/kg), twice (1 mg/kg every third day), or four (0.5 mg/kg every other day) times per week for 2 weeks, either alone or combined with radiation. The same radiation regimen was used in all experiments: 2-Gy fractions daily for 14 consecutive days, giving a total dose of 28 Gy to the tumor-bearing leg only. Tumor response was assessed by regrowth delay and dose modification factors (DMFs) obtained by comparing regrowth delay in the groups given 9-AC alone with those given the same dose of 9-AC and radiation. 9-AC significantly delayed tumor growth when combined with radiation, and this effect was dependent on drug dose; DMFs of 2.4 [95% confidence interval (CI), 2.0-3.1], 3.7 (95% CI, 3.1-4.6), and 3.3 (95% CI, 2.7-4.1) were obtained for groups treated with total drug doses of 2.0, 4.0, and 8.0 mg/kg 9-AC, respectively. In addition, the same total dose of 4 mg/kg 9-AC was more effective when given either twice or four times a week compared with once a week, giving DMFs of 2.8 (95% CI, 2.2-3.9), 2.6 (95% CI, 2.0-3.6), and 1.7 (95% CI, 1.3-2.4), respectively. The effect of 9-AC and radiation on normal tissue toxicity was assessed in two normal tissues, jejunum and skin, in separate groups of mice. Jejunal crypt cell survival was decreased in those mice given single doses of 9-AC ranging from 0.5-4.0 mg/kg and 12.5 Gy of total body radiation compared with those given 12.5 Gy of total body irradiation alone. The same regimen of drug and radiation did not modify acute skin reactions. These results suggest that 9-AC is an effective in vivo radiosensitizing agent when given in divided doses with fractionated irradiation. In addition, the gastrointestinal tract but not skin could be a critical target tissue for the use of 9-AC combined with radiation.     

The pharmacokinetics of Kefzol in patients with acute pancreatitis when administered intravenously and endolymphatically

Pharmacokinetics was studied of kefsole administered by intravenous and endolymphatic routes to patients (n = 23) with acute pancreatitis. The studies made showed that intravenous route for the drug administration makes for a quicker entering of the antibiotic into the peritoneal exudate. Apart from these reasons, endolymphatic antibacterial therapy does not appear to avert the development of complications involving pus-formation/discharging in acute pancreatitis and does not seem to be essential in the complex of therapeutic measures to be applied for treating the above patients.     

Essential phospholipids in the treatment of chronic pyelonephritis]

Through TCD test, observation on the blood flow dynamics change before and after treatment with 31 cases of the child cerebral atrophy was made. It is found that scalp therapy is able to speed up the blood flow of part artery, especially increase the even blood flow speed of MCA, ACA obviously (P < 0.05), which preliminary shows the mechanism of scalp therapy for child cerebral atrophy mean while. It is found that scalp therapy also has the function to restrain epilepsy.     

The effect of oxidative stress on structural transitions of human erythrocyte ghost membranes

The influenza virus hemagglutinin (HA) contains three highly conserved cysteine residues at positions 551, 559, and 562 close to the carboxyl-terminus of the HA2 subunit which serve as palmitylation sites. Wild-type HA of influenza virus A/FPV/Rostock/34 (H7N1) and HA permutated by exchange of the acylated cysteine to serine residues were expressed in CV-1 cells by a SV40 vector system. Since density of immunostained HA on the cell surface measured by flow cytometric analysis did not differ between wild-type and acylation mutants, it was possible to compare acylation mutants and wild-type HA for their capacity to induce membrane fusion at low pH. The following observations were made: (1) lateral diffusion of a lipid-like fluorophore (R-18) from the erythrocyte membrane to the plasma membrane of cells expressing HA on the surface occurred equally well with mutants and wild type. (2) Diffusion of a low-molecular-weight fluorescent water-soluble probe (calcein) from erythrocytes into the cytoplasm of HA-expressing cells was not altered either. (3) However, depending on the position and the number of the deleted acylation sites, the mutants showed a reduced ability to induce syncytia. The data indicate that deacylation of the cytoplasmic tail has no measurable effect on the capacity of HA to induce membrane fusion and pore formation but that it suppresses syncytia formation.     

GnRH molecular variants in the brain and pituitary gland of pejerrey, Odontesthes bonariensis (Atheriniformes). Immunological and chromatographic evidence for the presence of a novel molecular variant

Gonadotropin-releasing hormone (GnRH) molecular variants in the brain and pituitary gland of pejerrey, Odontesthes bonariensis (Atheriniformes), were characterized by gradient reverse phase high performance liquid chromatography (RP-HPLC). Eluted fractions were tested in radioimmunoassays with different antisera. The results show that the brain extract contains three forms of GnRH: one is immunologically and chromatographically similar to cIIGnRH (chicken II), and another is similar to sGnRH (salmon). A third GnRH appears to be chromatographic and immunologically different from the nine other known forms of the vertebrate hormone. This is the only variant present in the pituitary gland.     

Intracellular study of interaction of paired-pulse facilitation and late phase of hippocampal long-term potentiation]

Presynaptic paired-pulse facilitation (PPF) rate decreased in most CA1 pyramidal neurones following the long-term potantiation (LTP) induction. The decrease correlated with the LTP magnitude as well as with the initial (pretetanic) PPF rate. The data obtained suggests an involvement of presynaptic mechanisms in maintaining the early and the delayed LTPs.     

Surface enhanced Raman spectroscopy for characterization of structural characteristics of carbon chains in alpha1-acid glycoprotein and pseudoglycoproteins]

Surface-enhanced Raman scattering (SERS) spectroscopy was used to study the structure of carbohydrate chains in glycosylated forms of alpha 1-acid glycoprotein (AGP) and in pseudoglycoproteins obtained by transferring the carbohydrate chains of AGP to a polyacrylamide carrier. It was found that AGP-D glycoform and pseudoglycoproteins containing three or more glycans per molecule, which possess high immunomodulating activity, have a specific spatial organization of carbohydrate chains. This organization is maintained by the interaction of neighboring glycans with each other and does not depend on the nature of the carrier (whether it is polypeptide or polyacrylamide).