The effect of an H2-receptor antagonist on small-bowel colonization and bacterial translocation in newborn rats

Bacterial translocation (BT) is defined as the passage of enteric bacteria from the gastrointestinal tract to extraintestinal tissues. Bacterial overgrowth is one of the main promoting factors of BT, which is thought to play an important role in the pathogenesis of sepsis and necrotizing enterocolitis. It is believed that small-bowel colonization is established by bacterial spread through the rectum. Gastric acid is also involved in this process. An experimental study was designed for investigating the effect of gastric acid inhibition with the use of an H2-receptor antagonist on intestinal colonization and BT in newborn rats. Animals were divided into two groups: the ranitidine group (n = 20) received ranitidine 10 mg/kg per day intramuscularly for 5 days; the control group (n = 30) received saline solution. Mesenteric lymph node, spleen, liver, stomach, small bowel/cecum, and large bowel specimens were obtained from each rat 5 days later and gram-negative and -positive aerobic bacteria identified by the use of chocolate and Endo agar. It is concluded that: (1) there was a strong correlation between gastric and small-bowel bacterial colonization in the ranitidine group; (2) no correlation between large-and small-bowel colonization could be demonstrated; and (3) BT occurred only in the ranitidine group.     

On the phasic reflex bronchodilation in the cat

In records of tracheal pressure or flow taken from anesthetized cats appear large pressure-negative, or air inflow excursions, in response to single pulses applied to the central end of the vagus nerve. These responses have been attributed to phasic bronchodilation and not only due to the brief contractions of inspiratory muscles that occur as part of the total responses. Phasic bronchodilation responses appear mainly during inspiration but they may also occur in the expiratory phase through facilitation, during post-hyperventilatory apnea or that induced by constant current (d.c.) vagal stimulation. They are significantly reduced after lung sympathectomy. These bronchomotor responses showed long term depression (LTD) after spontaneous or reflexly evoked hiccups, and long term potentiation (LTP) after repetitive, or d.c. vagal stimulation. They are also potentiated on the experimental conditions that include exaggerated sympathetic activity. These and some other characteristics described indicate that bronchomotor responses are legitimate and can be used to follow the changes in excitability of the central generator of breathing.     

Thermoeconomic optimization of subcooled and superheated vapor compression refrigeration cycle

An exergy-based thermoeconomic optimization application is applied to a subcooled and superheated vapor compression refrigeration system. The advantage of using the exergy method of thermoeconomic optimization is that various elements of the system—i.e., condenser, evaporator, subcooling and superheating heat exchangers—can be optimized on their own. The application consists of determining the optimum heat exchanger areas with the corresponding optimum subcooling and superheating temperatures. A cost function is specified for the optimum conditions. All calculations are made for three refrigerants: R22, R134a, and R407c. Thermodynamic properties of refrigerants are formulated using the Artificial Neural Network methodology.     

Prevalence of hepatitis B and C virus markers among the members of the medical-sanitary staff from the Faculty of Dentistry "Carol Davila" University of Medicine and Pharmacy, Bucharest

5-Methylcytosine (5mC) levels were determined in compositional DNA fractions corresponding to different isochore families from the genomes of Xenopus, chicken, mouse and human, four vertebrates which show different isochore patterns. The results obtained indicate that: (i) positive correlations exist between the 5mC levels and the GC levels of isochores within any given genome; and (ii) DNA from Xenopus isochore families is twice as methylated as DNA from the isochores having the same GC levels from mouse, human and chicken. Moreover, the positive correlations holding between CpG levels and the GC3 levels of coding sequences of warm-blooded vertebrates were shown to comprise two regions with a border at approx. 75% GC3. The correlation corresponding to the higher region (which comprises only very rare high GC3 values in the case of Xenopus) has a higher slope than that corresponding to the lower GC3 values, a phenomenon due in all likelihood, to the increasing contribution of CpG islands. Finally, the observed/expected CpG ratio is higher in Xenopus than in warm-blooded vertebrates.     

Extraction of yuxtaureteral suture, with ureteroscopy. A clinical case]

Severe protein deprivation at weaning provokes an arrest of cellular proliferation and maturation, and an increase of ADA and PNP activities in the thymus of growing rats. A 20% casein diet fed during 9 days was enough to reverse the effect on ADA and PNP. The supplementation with 24 mg/d of n-3 PUFA, was able to recover thymus' cellular proliferation and maturation.     

Fast fault simulation for nonlinear analog circuits

A new method of transient fault simulation uses dc bias grouping of faulty circuits and decreases the number of Newton-Raphson iterations needed to reach a solution. An experimental tool implementing this method achieves a speedup of 20% to 30% on a flat netlist.     

A non-local stress failure condition for structural elements under multiaxial loading

A non-local stress condition for crack initiation and propagation is proposed and applied to several particular cases, such as plate with wedge-shaped notch, elliptical hole and hyperbolic notch. Brittle failure initiation for notched elements under complex loading (Modes I and II) is studied in detail. A value of critical load and crack orientation is predicted from the non-local condition, which is applicable to both regular and singular stress concentrations.     

Effect of Cervitec varnish on the salivary Streptococcus mutans levels in the patients with fixed orthodontic appliances

The aim of the present study was to assess the efficiency of a 1% chlorhexidine-containing varnish (Cervitec, Vivadent, Liechtenstein) on the levels of Streptococcus mutans in saliva of patients with fixed orthodontic appliances using the Dentocult-SM (Vivadent, Liechtenstein) technique for the microbiological investigation. Eighty subjects participated in the study and, divided randomly into two equal groups in which one group was treated with the placebo varnish (Vivadent, Liechtenstein) for negative controls. Streptococcus mutans in saliva of the subject was sampled and enumerated by using the Dentocult-SM dip-slide technique for periods of one, two four and twelve weeks after a single varnish application. The results were evaluated statistically. After the chlorhexidine containing varnish treatment the levels of Streptococcus mutans in saliva were significantly reduced after one week (p < 0.01) and continued reduction for one month (p < 0.05). After twelve weeks Streptococcus mutans levels in saliva were given a relative increase. No significant suppression was found in the placebo group (p > 0.05). The results suggested that Cervitec varnish reduces salivary Streptococcus mutans levels and that the application should be repeated every 3 months to get antibacterial effect.     

Effect of maternal age on the course of labor--analysis of women over 40 years of age

The scientific investigations conducted first allow using a method of fluorescent probes for the diagnosis of human coronaviral intestinal infection. The method is characterised by sensitivity, specificity, reproductivity and proximity. It is comparable, according to these parameters, with the methods of the third generation and may be recommended for putting into practical work of virological laboratories.     

Local minimizer of a nonconvex quadratic programming problem

A modified Beale's algorithm is described which computes the local minimizer of any quadratic objective function subject to linear constraints. Some extensions are given, first of all the possibility of movement to the neighbouring local minimizer with a reduced objective function value in some special cases.