Central V1b receptor antagonism in lactating rats: impairment of maternal care but not of maternal aggression.

Maternal behaviour in rodents is mediated by the central oxytocin and vasopressin systems, amongst others. The role of vasopressin, acting via the V1a receptor (V1aR), on maternal care and maternal aggression has recently been described. However, a potential involvement of the V1b receptor (V1bR) in maternal behaviour has only been demonstrated in knockout mice. The present study aimed to examine the effects of central pharmacological manipulation of the V1bR on maternal behaviour in lactating Wistar rats. On pregnancy day 18, female rats were implanted with a guide cannula targeting the lateral ventricle. After parturition, dams received an acute central infusion of a specific V1bR agonist (d[Leu4,Lys8]VP) or V1bR antagonist (SSR149415) once daily, followed by observations of maternal care [lactation day (LD) 1], maternal motivation in the pup retrieval test (LD 2), anxiety-related behaviour on the elevated plus-maze (LD 3) and maternal aggression in the maternal defence test followed by maternal care monitoring (LD 4). Our data demonstrate that, under nonstress conditions, the V1bR antagonist decreased the occurrence of both nursing and mother-pup interaction, whereas the V1bR agonist did not affect either parameter. Under stress conditions (i.e. after the maternal defence test), mother-pup interaction was decreased by infusion of the V1bR antagonist. During the maternal defence test, neither treatment affected aggressive or non-aggressive behaviour. Finally, neither treatment altered maternal motivation or anxiety. In conclusion, central V1bR antagonism modulates aspects of maternal care but not of maternal aggression or maternal motivation in lactating rats. These findings further extend our knowledge on the vasopressin system as a vital mediator of maternal behaviour.

Coronary stent implantation in diabetic versus nondiabetic patients. Early and late outcomes.

OBJECTIVE: To assess whether coronary stenting in diabetic patients provides in-hospital results and clinical evolution similar to those in nondiabetic patients. METHODS: From July '97 to April '99 we performed coronary stent implantation in 386 patients with coronary heart disease, who were divided into two groups: diabetic patients and nondiabetic patients. The in-hospital results and the clinical evolution of each group were retrospectively analyzed. RESULTS: The nondiabetic group comprised 305 (79%) patients and the diabetic group 81 (21%) patients. Basic clinical and angiographic characteristics were similar. Angiographic success was in diabetics = 96.6% vs in nondiabetics = 97.9% (p=ns). Among the major complications in the in-hospital phase, the rate of myocardial infarction was higher in the diabetic group (7.4% vs 1.9%) (p=0.022). In the follow-up, a favorable and homogeneous evolution occurred in regard to asymptomatic patients, myocardial infarction, and death in the groups. A greater need for revascularization, however, existed in the diabetic patients (15% vs 2.4%, p<0.001). CONCLUSION: Coronary stenting in diabetic patients is an efficient procedure, with a high angiographic and clinical success rate similar to that in nondiabetic patients. Diabetic patients, however, had a higher incidence of in-hospital myocardial infarction and a greater need for additional myocardial revascularization.

Long-term follow-up of pregnant women after percutaneous mitral valvuloplasty.

The aim of this study was to evaluate long-term clinical follow-up and echocardiographic data on pregnant patients with mitral stenosis who underwent percutaneous mitral valvuloplasty (PMV) in our center and the development of their infants. PMV has proven to be an effective alternative to treat pregnant patients with mitral stenosis. However, long-term outcome of these patients, as well as the potential harmful effects caused by radiation on their infants, still awaits to be determined. From January 1988 to February 1999, 30 pregnant women (mean gestational duration, 24.95 +/- 5.59 weeks) underwent PMV. Twenty-three (77%) were subsequently followed by a medical interview during 5.33 +/- 3.12 years. Clinical variables such as NYHA functional class (FC), the need of a repeat PMV or surgical procedure, the presence of embolic events, and mortality rate were evaluated during follow-up. Mitral valve area, mean transmitral gradient, and the presence of mitral regurgitation were also assessed by Doppler echocardiography. Clinical data on the development of the infants were obtained from the assistant pediatricians. All patients were in NYHA FC III or IV before the procedure. During follow-up, 91% of them were in FC I and II. Two patients (9%) who had remained in FC III underwent a repeat successful PMV; no further surgery was required. There were no embolic events or death related to the procedure. Echocardiography showed an initial increase in mitral valve area from 1.14 +/- 0.22 cm(2) to 2.01 +/- 0.21 cm+/- (P < 0.0001). During long-term follow-up, it decreased to a mean of 1.75 +/- 0.24 cm(2) (P < 0. 0001). Initial transmitral valve gradient decreased from 17.73 +/- 4. 56 mm Hg to 5.91 +/- 1.80 mm Hg (P = 0.0001) and 8.95 +/- 3.58 (P = 0.002) during long-term follow-up. Twenty one children (96%), aged 4. 91 +/- 2.8 years, showed normal growth and development, and no clinical abnormalities were observed. These favorable long-term results suggests PVM to be the procedure of choice to treat pregnant women with mitral stenosis who remain in FC III or IV despite adequate medical therapy. No harmful effects due to the use of radiation were observed in the children.

Prevention of catheter-related infections by a new, catheter-restricted antibiotic filling technique.

Catheter-related infections pose a hazard to both humans and laboratory animals. The aim of this study was to develop a technique preventing bacterial colonization of intravascular catheters. In 27 dogs a total of 70 catheters were implanted. On an average catheters were used for 207 days. Three protocols were compared: (1) flushing the catheters with a heparinized solution; (2) filling only the catheter lumen with alpha-chymotrypsin solution (225 units/ml); (3) filling only the catheter lumen with a solution containing a mixture of the aminoglycoside antibiotic gentamicin (20 mg/ml) and chymotrypsin (225 units/ml). Catheter fillings were always withdrawn before catheter use. Catheter exit sites were all treated with povidone iodine ointment once a day. Body temperatures and weights were recorded, bacteriological and electron microscopical examinations of catheters performed. Without gentamicin filling all catheters were colonized after a few weeks. The dogs showed clinical signs of chronic bacteraemia. Gentamicin filling eradicated colonization. No further bacteraemia was observed. We conclude that filling only the catheter lumen with a concentrated solution of chymotrypsin and gentamicin, combined with measures to prevent infections via the subcutaneous catheter tunnel, is an effective and safe technique to prevent catheter-related infections.