The significance of gastric helicobacteriosis in the genesis hemorrhage from duodenal peptic ulcer

Based on a comprehensive analysis of findings from examination and surgical treatment of 196 patients with bleeding pyloroduodenal ulcers, it was found out that patients with concurrent helicobacteriosis of the stomach are prone to more unfavourable course of their illness, which fact is evidenced by a greater loss of blood and higher risk for bleeding recurrences. A classification is proposed by the authors, taking advantage of the data from endoscopic, microscopic and immunoenzymatic techniques, with the purpose of providing an assessment of degree of severity of helicobacteriosis of the stomach.     

Revascularization of calvarial, mandibular, tibial, and iliac bone grafts in rats

The development of approaches to screening of hospital patients for harmful drinking frequently encounters resistance from both patients and hospital staff. A contributing factor could be the discomfort both feel about talking specifically about drinking. One approach to reducing this discomfort has been to mask concern about alcohol consumption into a general focus on other health and lifestyle issues. One-hundred and eighty-two patients admitted to an emergency department were presented randomly with either a straight alcohol screening questionnaire or a general health and lifestyle questionnaire with alcohol questions embedded amongst items on smoking exercise and diet. The number of returns was equal for both questionnaires which suggests the masked questionnaire does not improve the acceptability of alcohol screening in hospital environments.     

K-ras gene mutations: an unfavorable prognostic marker in stage I lung adenocarcinoma

Activation of K-ras gene by point mutations, a common finding in lung adenocarcinomas, has been suggested to decrease patient survival. We investigated 109 lung adenocarcinomas, mostly small, peripheral, stage I tumours (81/109) for presence of K-ras gene mutations at codons 12 and 13. Mutations were detected by denaturing gradient gel electrophoresis analysis of specific sequences amplified by polymerase chain reaction from DNA extracted from archival pathological material. Thirty-three of 109 (30.3%) tumours showed mutations at codon 12 (28/33, 84.8%) or 13 (5/33, 15.2%) of the gene. Mutations and type of nucleotide substitutions were differently distributed among cytological subtypes, being more prevalent among less differentiated (G2 and G3) tumours and among bronchial than bronchiolo-alveolar type adenocarcinomas. Survival analysis showed an adverse effect of K-ras mutation on survival, restricted to stage I tumours. Median survival for 81 stage I patients was 30 months for non-mutated tumours versus 20 months for mutated tumours (p = 0.016). Multivariate analysis showed that age of patient (p = 0.001) and K-ras mutation status (p = 0.04) were the only independent factors influencing survival significantly. These data strengthen the hypothesis that K-ras gene mutations may be useful in identifying a subgroup of patients with poor outcome.     

Kinetic analysis of the coding properties of O6-methylguanine in DNA: the crucial role of the conformation of the phosphodiester bond

Production by N-nitroso compounds of O6-alkylguanine (O6-alkylG) in DNA directs the misincorporation of thymine during DNA replication, leading to G:C to A:T transition mutations, despite the fact that DNA containing O6-alkylG:T base pairs is less stable than that containing O6-alkylG:C pairs. We have examined the kinetics of incorporation by Klenow fragment (KF) of Escherichia coli DNA polymerase I of thymine (T) and of cytosine (C) opposite O6-MeG in the template DNA strand. Both T and C were incorporated opposite O6-MeG much slower than nucleotides forming regular A:T or G:C base pairs. Using various concentrations of dTTP, dCTP, or their phosphorothioate (Sp)-dNTP alpha S analogues, or a mixture of dTTP and dCTP, the progress of incorporation of a single nucleotide in a single catalytic cycle of a preformed KF-DNA complex was measured (pre-steady-state kinetics). The results were consistent with the kinetic scheme (Kuchta, R. D., Benkovic, P., & Benkovic, S. J. (1988) Biochemistry 27, 6716-6725): (1) binding of dNTP to polymerase-DNA; (2) conformational change in polymerase; (3) formation of phosphodiester between the dNTP and the 3'-OH of the primer; (4) conformational change of polymerase; (5) release of pyrophosphate. The results were analyzed mathematically to identify the steps at which the rate constants differ significantly between the incorporation of T and C. The only significant difference was the 5-fold difference in the rates of formation of the phosphodiester bond (for dTTP, kforward = 3.9 s-1 and kback = 1.9 s-1; for dCTP, kforward = 0.7 s-1 and kback = 0.9 s-1). These pre-steady-state progress curves were biphasic with a rapid initial burst followed by an apparently steady-state rise. Deconvolution of these curves gave direct evidence for the importance of the conformational change after polymerization by showing that the curves represented the sum of the rapid accumulation of the product of step 3 followed by the slow conversion of that to the product of step 5 (because of the rapidity of the release of pyrophosphate there was no significant accumulation of the product of step 4). The equilibrium constants for each step suggest that the greatest change in the Gibbs free energy occurs at the conformational change after polymerization and that while the formation of the phosphodiester bond to T is slightly exothermic, that to C is slightly endothermic.(ABSTRACT TRUNCATED AT 400 WORDS)     

Synthesis and evaluation of the inhibitor effect of a new class of triazole compounds

In this work, a new class of triazole molecules, containing heteroatoms such as nitrogen and sulphur, is prepared. The effect of these molecules on the corrosion behaviour of iron was investigated. Electrochemical studies were performed in aerated chloride acid solution (1 M) by potentiodynamic polarisation curves. Surfaces were characterised by scanning electron microscopy.

The recorded electrochemical data showed that the corrosion resistance was greatly enhanced in the presence of inhibitor. The maximal protection efficiency exceeded 94%. The corrosion protection could be explained by the adsorption of inhibitor through the S- or N-atom and formation of a protective layer attached to the metal surface.     

Persistence of decreased T-helper cell function in industrial workers 20 years after exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

OBJECTIVE: To evaluate the distribution of mepivacaine hydrochloride after distal interphalangeal (DIP) joint injection in horses. DESIGN: Prospective, uncontrolled study. ANIMALS: 10 adult horses. PROCEDURE: 30 minutes before euthanasia, 8 ml of 2% mepivacaine hydrochloride was injected into the dorsal pouch of a forelimb DIP joint. Synovial tissue from the DIP joint and podotrochlear (navicular) bursa and bone tissue from the medullary cavity of the distal sesamoid (navicular) bone were taken from both forelimbs immediately after death. All synovial and bone specimens were analyzed for tissue concentration of mepivacaine by high-performance liquid chromatography. Synovial tissue and bone specimen concentrations from the injected forelimb were compared with corresponding specimens from the noninjected forelimb. All synovial tissue and bone specimen concentrations were compared with an estimated effective tissue concentration of mepivacaine (0.3 microgram/mg) for local anesthesia. RESULTS: Specimen concentrations of mepivacaine from the injected forelimb were significantly greater (P < 0.05) than those in the corresponding tissues of the contralateral noninjected forelimb. All DIP joint and navicular bursa synovial tissue specimens from the injected forelimb had greater than the estimated effective tissue concentration of mepivacaine for local anesthesia. Of the 10 navicular bone specimens from the injected forelimb, 4 were higher and 2 were within 20% of the estimated effective tissue concentration of mepivacaine for local anesthesia. CONCLUSIONS: Mepivacaine hydrochloride deposited into the DIP joint should anesthetize pain arising from navicular bursa synovia and may decrease pain arising from the medullary cavity of the navicular bone. CLINICAL RELEVANCE: DIP joint injection of mepivacaine hydrochloride is not specific for DIP joint pain.     

Using indices to differentiate dimensions of knowledge regarding modes of HIV transmission in the U.S. population, 1987-1989

Spores of Bacillus subtilis NCTC 8236 were treated with glutaraldehyde, Lugol's iodine, polyvinylpyrrolidone-iodine (PVP-I), sodium hypochlorite or sodium dichloroisocyanurate (NaDCC). After exposure survivors were enumerated on nutrient agar containing potential revival agents (subtilisin, lysozyme, calcium dipicolinate, calcium lactate). Of these, only calcium lactate had any significant enhancing effect and then only with iodine-treated spores. Calcium lactate (9 mmol l-1) in nutrient broth enhanced the rate and extent of germination of iodine-treated spores but not of spores previously subjected to glutaraldehyde, hypochlorite or NaDCC.     

Regulation and function of steroid production by mid gestation ovine fetal adrenal cortex in vivo

By mid-gestation (75-85 days, term=150 days), the ovine fetal adrenal gland is zoned into cortex and medulla. The cortex has an outer layer of cells which have the morphological characteristics of zona glomerulosa cells, containing mitochondria with lamellar cristae. It has been reported that cultured adrenal cells from mid-gestation bovine and ovine fetuses can be stimulated to increase aldosterone production, ten fold, by angiotensin II, and that this can be maintained for at least 3 days. However, the situation in vivo is unknown. In the current report we show that in chronically cannulated ovine fetuses at mid-gestation, angiotensin II (1 microg/h) does not increase aldosterone either in the short term (3 hours) or long term (3 days). However, ACTH (450 ng/h) can increase plasma aldosterone in the short but not long term. ACTH at this dose produces progressive and large increases in cortisol production. Angiotensin II is pressor and produces a modest diuresis without stimulating cortisol.