Clinical and biological acceptance of a fibrocollagen-coated mersylene patch for tracheal repair in growing dogs.

BACKGROUND: Collagen-covered prostheses can be used as a non-circumferential segmental tracheal replacement. However, the applicability of these implants in young subjects has not yet been reported. METHODS: In this experimental, longitudinal study, dogs aged 29-32 days underwent limited segmental tracheal replacement with a polyester prosthesis or were allocated to a control, untreated group. The dogs were evaluated clinically, endoscopically and tomographically for up to one year. RESULTS: Although there was evidence of tracheal growth in the experimental group, tomographic measurements were significantly smaller in this group than in the control group throughout the observation period. At the end of the study, there was no evidence of implant rejection, stenosis or collapse. Normal respiratory epithelium had grown across the implanted membrane in the experimental group. CONCLUSION: The homologous collagen mersylene membrane allowed for limited structural tracheal growth and was functionally integrated into the segmented tracheal wall in growing dogs.

Study of intrinsic flow properties at the normal pregnancy second trimester.

During normal pregnancy the cardiovascular system undergoes extensive changes. In a previous work we demonstrated the role of the haemorheological profile as predictor of hypertensive gestational disorders through a retrospective study. In an attempt to clarify the rheological characteristics during normal gestation, blood and plasma viscosity, erythrocyte deformability and aggregation, and plasma fibrinogen levels were measured at second trimester of pregnancy. The interrelationships of different haemorheologic parameters, were analysed by Pearson correlation coefficient. The results showed decreased erythrocyte deformability, and increased plasma viscosity and erythrocyte aggregation due to increased fibrinogen in pregnant women. Despite these modifications blood viscosity did not increase, but there was a decrease in relative blood viscosity, therefore, a profile in accordance, from the haemorheological point of view, with the classical concept stating that haemodilution is of the utmost importance to maintain an adequate microcirculation in the uteroplacental unit during normal gestation.

Pharmacokinetics of a cephalone (CQ-M-EPCA) in rats after oral, intraduodenal and intravenous administration.

As part of the development of a new series of antibacterial agents derived from coupling a beta-lactamic precursor with a fluoroquinolone and named cephalones, the pharmacokinetics of one derivate: CQ-M-EPCA in rats after intravenous, intragastric and intraduodenal routes, was carried out. After the IV injection of 20 mg/kg or 40 mg/kg of this cephalone, plasma concentrations at the time zero (Cp0) were 3.1 and 11.26 microg/ml, respectively. Plasma concentrations decreased rapidly to almost disappear in both instances. Forty-five minutes later, a surge in concentrations, in the 40 mg/kg group, with a maximal plasma concentration (Cpmax) of 2.97 microg/ml was observed. An elimination half-life (T1/2el) of 2.36 +/- 0.33 h. was calculated. The drug was undetected by the ninth hour. Intragastric administration of the drug resulted in Cpmax of 3.78 +/- 0.26 microg/ml with a time to reach Cpmax (Tmax) of 25 min and T1/2el = 3.22 h. Same variables after intraduodenal administration were Cpmax 4.71 microg/ml; Tmax 1h, and T1/2el 3.41 h. Outstandingly high bioavailabilities after intragastric and intraduodenal administration (169 and 246%, respectively), together with the shape of the concentration versus time profiles after IV administration suggest that the drug undergoes a complex redistribution phenomenon, while showing high tissue diffusion with an apparent volume of distribution of 3.33 l/kg.

Proposal of a haemorheological profile for early detection of hypertensive gestational disorders.

The objective of this study was to emphasise the potential power of simple and inexpensive haemorheological tests as predictors of hypertensive gestational disorders through a retrospective study. Blood samples of 195 primigravids with gestational age 18-23 weeks were studied. For data processing pregnant women were allocated into 3 groups, based on difference of SBP and DBP values measured at first and last consultation, and presence of proteinuria and oedema: Normotensive pregnants (n=149), hypertensive pregnants; n=26 and preeclamptic pregnants; n=20. Whole blood viscosity, plasma viscosity, erythrocyte rigidity and aggregability, haemoglobin, hematocrit, total protein, albumin and fibrinogen were assayed. Increased relative viscosity (eta(r)) (p<0.01), decreased erythrocyte deformability (p<0.05), lower O(2) release (p<0.01) and birth weight (p<0.01), showed a negative correlation with filterability index in preeclamptics. There was a decrease of erythrocyte deformability in hypertensive women. Erythrocyte deformability and blood viscosity could be an early indicator in preeclamptics, and erythrocyte deformability in hypertensive ones, therefore they could be considered alert factors in order to decide a thorough control in these patients to prevent further complications.

Effect of hormone replacement therapy upon haemorheological variables.

It is already admitted that hormone replacement therapy (HRT) decreases the risk of developing cardiovascular disease, although its mechanism is not clear yet. In the present work, the effect of the HRT upon cellular and plasmatic haemorheological factors determining blood flow properties: blood viscosity, plasma viscosity, plasma fibrinogen, rigidity erythrocyte index and erythrocyte aggregation rate was studied. Menopausal women were followed through a whole year of HTR. Results demonstrate that after six months of treatment there is a diminution in relative blood viscosity and erythrocyte rigidity, with constant values along the second semester. Erythrocyte aggregation, plasmatic and blood viscosity diminution observed during the treatment can be explained by the simultaneous plasma fibrinogen decrease. Modified cellular and plasmatic rheology could produce beneficial effects on blood flow, particularly in microcirculation, presenting a possible mechanism by which HTR decreases the risk of cardiovascular disease development during menopause.

Tachycardia: an autosomal, monogenic, biallelic, recessive trait.

A brief commentary of the genetics of blood pressure is presented. The importance of the mechanisms of blood pressure regulation, among which heart rate is relevant, is emphasized. The analysis of a small population to test the quantitative model of the trait heart rate, considered as a metric character, is presented. The analysis of heart rate fitting to a qualitative model of inheritance is carried out. The results displayed might support the hypothesis that tachycardia could be an autosomal, monogenic, biallelic recessive trait.

[The correlation of arterial pressure with weight and body mass index]. / Correlación de presión arterial con peso e índice de masa corporal.

OBJECTIVES: To analyze the influence of weight and different body mass indexes on blood pressure (BP) values. The study was carried out in 823 volunteers (345 males, 478 females), aged 25/80 years. A standardized protocol, based on the recommendations provided by the V Joint National Committee was set up. The means of three consecutive readings taken at 2-min. intervals on three occasions were used. Weight and height were determined and the indexes were calculated. Correlations between weight and the selected indexes, with SBP and DBP, respectively, by sex and age interval were performed. The most representative indexes were body mass index (BMI) followed by lean BMI and weight. Analysis of BP values are BMI, for a period starting at 25 years and ending at 74 year, for both SPB and DBP, in comparison with the Humboldt Study data was performed, showing a strikingly similar pattern of behavior with our data. Additionally, weight and BMI are more closely associated with DBP in males than in females. Conversely, this association is closer in women with SBP. The importance of the ethnic factor is emphasized in order to establish body mass index cut-off values regarding the population under study, because the values proposed by the American Heart Association are probably rather high for our population.

[Experimental enteral segmental transplant. Functional response and surgical complications]. / Trasplante segmentario enteral experimental. Respuesta funcional y complicaciones quirúrgicas.

BACKGROUND DATA: Total enteral transplant associated or not to other abdominal organs has a high degree of morbidity due to immunologic and functional complications that have limited its therapeutic application. Segmentary transplants have demonstrated experimentally to have a better control to immune response, however there are still doubts on its functional effectiveness in terms of other segments. OBJECTIVE: In order to evaluate surgical and functional morbidity without immunologic interference, syngenic segmentary enteral transplants were done, from three different levels in the intestine. METHOD: Growing syngenic Lewis rats were randomly divided into five groups; four of them had 90% enterectomy with a simultaneous transplant of a 30% of the proximal, medial and distal segments in the first three groups and 90% in the fourth one. The fifth group was used as a control. RESULTS: Of the 54 rats that were transplanted, one third developed late complications. Only half of them showed controllable causes, the complications were proportional in all groups. Among surviving four months after transplant, no group had stopped growing, however, the proximal transplant group had significant (P < 0.05) deficit in weight with respect to the other groups. All the other groups showed growth patterns similar to the control group. Plasma concentrations of tryglicerydes, cholesterol and glucose after the maltosa test were similar in all animals. Low albumin concentrations were observed only in the proximal transplant group (P < 0.05). CONCLUSIONS: Medial and listal segmentary transplants showed the best functional adaptability in terms of ponderal growth, similar to animals with total enteral restitution or intestinal integrity.