Cortisol and immune measures in boars exposed to three-day administration of exogenous adrenocorticotropic hormone

The aim of the study was to evaluate the effect of adrenal stimulation by adrenocorticotropic hormone (ACTH) on blood cortisol concentration and on circulating total and differential leukocyte counts during and in the 16 days after ACTH administration. Swedish Landrace boars aged approximately 6-7 months were used. ACTH-treated animals (n = 7) were given ACTH intravenously at 10 microg/kg body mass for 3 days. A control group of animals (n = 7) received 1 ml of sterile 0.9% saline intramuscularly. ACTH induced a highly significant increase (p>0.0001) in serum cortisol in treated boars. On the day after the last ACTH dose, the cortisol concentration was significantly higher, but the level of significance was lower than during ACTH administration (p>0.05). During ACTH treatment, a significant increase was recorded in total leukocyte count and neutrophil percentage (p>0.05 to p>0.0001), along with the increase in blood cortisol concentration, whereas percentage lymphocyte count showed a significant decrease. Lymphopenia disappeared upon cessation of treatment, but neutropenia developed in the week after treatment. On all three days of ACTH challenge, the neutrophil-to-lymphocyte ratio was significantly increased. An increase in eosinophil percentage was recorded on treatment days 1 and 2, whereas ACTH treatment had no effect on basophil percentage. In conclusion, three-day administration of ACTH to young boars during restraint caused effects similar to acute stress situations, as suggested by disappearance of the effects on immune function after the last drug dosage.

Distribution of airborne bacteria in swine housing facilities and their immediate environment

This paper describes a bacteriological analysis of air samples taken from swine housing facilities and the immediate environment. The air volume of the samples was pre-programmed by a standard air sampler (MAS-100, Merck) and was directly impacted onto the bacteriologic agar surface (Petri dishes, standard diameter of 90 mm). The bacterial contamination in forty-eight samples was 2.59 x 10(5) CFU/m3 (ranging from 8.46 x 10(4) to 5.30 x 10(5) CFU/m3). Potentially pathogenic bacterial agents predominated in all samples (100%), while primarily pathogenic bacteria were isolated in a minor proportion of samples (33%-66%). Airborne bacterial contamination in samples (N = 16) obtained from emptied facilities ranged from 1.8 x 10(3) CFU/m3 (that is, after coarse mechanical washing) to 0.8 x 10(2) CFU/m3 (upon completion of disinfection). Control measurements at different locations and distance from the farm (N = 32) pointed to the presence of non-pathogenic airborne bacteria, ranging from 1.55 x 10(2) to 3.70 x 10(2) CFU/m3. The results of this preliminary study showed that the emission of potentially pathogenic bacteria from animal housing facilities to the immediate farm environment via aerosol was very low.

Ventricular performance following valve replacement for chronic mitral regurgitation: importance of chordal preservation

OBJECTIVE

To assess immediate and late changes in left ventricular performance after mitral valve replacement (MVR) for mitral regurgitation with or without preservation of chordae tendineae.

EXPERIMENTAL DESIGN

a prospective, one year follow-up, study.

SETTING

university cardiosurgical hospital.

PATIENTS

Fourteen patients with symptomatic chronic mitral regurgitation were divided into Group A (n = 7), which underwent MVR with chordal preservation, and Group B (n = 7) which underwent MVR with chordal transection.

METHODS

Transesophageal echocardiography, obtained simultaneously with radial artery and pulmonary capillary wedge pressures over a range of loading conditions, was used to estimate left ventricular elastance (Eps), calculated as the slope of peak systolic pressure/end-systolic volume relation, and preload recruitable stroke work (PRSW). Measurements were taken intraoperatively before and after cardiopulmonary bypass, 6 hours later and 10 days later. Transthoracic echocardiography follow-up data were obtained after 3 months and one year.

RESULTS

Eps significantly decreased immediately after MVR (p = 0.018), with no difference among 2 groups. Eps gradually increased to preoperative levels 10 days after surgery. PRSW also significantly decreased after MVR (p = 0.01). The decrease was significantly larger in Group B (p = 0.038). During follow-up, Group A showed a significantly better ejection fraction (p = 0.008), and a smaller end-systolic volume index (p = 0.01) and left ventricular mass index (p = 0.04), than Group B.

CONCLUSIONS

These data support the hypothesis that chordal preservation during MVR has beneficial effects on left ventricular performance.

Chordal preservation improves postoperative ventricular performance following valve replacement for chronic mitral regurgitation

Worsening of left ventricular performance had been recognized after mitral valve replacement for mitral regurgitation. The effects of chordal preservation on ventricular performance after mitral valve replacement have been assessed. Twelve patients with mitral regurgitation were allocated to group A (undergoing mitral valve replacement with chordal preservation), or to group B (undergoing mitral valve replacement with chordal excision). Transoesophageal echocardiography was recorded simultaneously with radial artery and pulmonary capillary wedge pressures. Load was varied by withdrawal of blood from a venous line of cardiopulmonary bypass and/or nitroglycerine bolus. Ventricular performance was assessed by the slope of peak systolic pressure-end-systolic volume relation (Eps), and by the slope of the left ventricular stroke work-end-diastolic volume relationship. Eps significantly decreased immediately after mitral valve replacement (P < 0.02), with no difference among two groups. Eps gradually increased to preoperative levels 10 days after surgery. Pre-load recruitable stroke work also significantly decreased after mitral valve replacement (P = 0.01). The decrease was significantly larger in group B (P < 0.04). These data support the hypothesis that chordal preservation during mitral valve replacement has beneficial effects on left ventricular performance.

[Perioperative myocardial failure and mechanical cardiac support --a five year experience]

Inability to wean a patient from the cardiopulmonary bypass after open heart procedure is reality of the clinical practice. The only realistic chance for these patients is some form of mechanical circulatory support. Over the period from November 1988 to November 1993, in 17 patients the roller-pump mechanical assist device was inserted, i.e. 0.47% of 3589 patients were operated on during this period. Thirteen patients required mechanical circulatory support immediately after surgical procedure due to inability to wean them from cardiopulmonary bypass. In three patients the roller-pump was inserted preoperatively (percutaneous insertion), and in one patient mechanical circulatory support was started six hours after the procedure for sudden cardiac deterioration. Partial and temporary "bypass" of the damaged left ventricular function is achieved by insertion of inflow cannula into the left atrium, and outflow cannula into the ascending aorta. Depending on the inflow cannula size and volume load, we were able to achieve blood flow of 3.5 to 5 liters/minute. Using this system we were able to improve the left ventricular function in eight patients (47%), and five patients were discharged from hospital (29.4%). The roller-pump mechanical circulatory support proved to be efficient, reliable, easy to monitor and operate. Overall results are comparable to the published data as well as to other types of more versatile and costly devices for mechanical circulatory support.