Biomedical subjects

P Aldazabal

Publications and source records attributed to P Aldazabal.

21 records · Page 2Linked to original sources

PubMed1991

Transperitoneal exchanges of water and solutes in the fetus with gastroschisis. Experimental study in the chick embryo.

Aiming at testing the hypothesis that, in the foetus with gastroschisis (GX) peritoneal dialysis during antenatal bowel exposure to the amniotic fluid may induce some modifications of the internal environment, we have studied the composition of blood, amniotic fluid and allantoic fluid in a chick embryo model of GX. Intestinal loops were surgically eviscerated in 184 embryos on the 14th day of incubation and exposed to the mixture of both embryonal fluids until the 19th day (hatching expected at the 21th). Typical lesions of GX were present in half of the 94 survivors (n = 42). For comparison we used a control group of non-manipulated animals (n = 19) and a "sham" group of animals in which the operation was carried out only until umbilical manipulation but without bowel exposure (n = 22). Chicks with GX were smaller and slightly dehydrated as attested by clinical signs and had moderately increased hematocrit. They had significant hyperkaliaemia and slight decreases in serum Na and Cl. Urea, total protein and protein fractions were not modified. Taking into account the gradients for such substances existing between the dialysate (amino-allantoic mixture) and the embryonal blood, the changes observed, albeit slight, suggest that there was some evidence of dialysis through the peritoneum: lower Na and Cl concentrations in the dialysate than in blood, induced slight falls in serum Na and Cl whereas higher K concentration resulted in severe hyperkaliemia. The high levels of albumin in the chick amniotic fluid did not allow protein depletion and therefore total protein and its fractions remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗

PubMed1990

Spina bifida: a chick embryo experimental model.

Neural Tube Defects (NTD) can be induced in the chick embryo with relative ease in order to provide an experimental tool for investigation of such disabling malformations. Domestic hen (Gallus gallus) eggs were incubated at 37.5 degrees C and 80% humidity for 24 h. At that moment, 5 ml of albumen were aspirated by sterile puncture of the shell, and the incubation was resumed. The embryos were recovered and studied at the 8th, 10th and 14th days. Almost half (45%) of the 602 treated embryos survived and 73 of them (12%) had various malformations. Thirty-six (6%) suffered NTD of which 30 were open myelomeningocele, 2 meningocele and 4 encephalocele. The anatomy of the defects was astonishingly similar to that of the human malformation. Whether these experimental NTD are induced by mechanical or nutritional modifications of the internal environment of the egg is unknown, but the similarity of the lesion with those in humans make them suitable for further investigation of these issues. We believe that this relatively simple and inexpensive model is a suitable tool for research on spina bifida.

Animals↗

PubMed1989

[The chick embryo as a model of fetal surgery: intestinal atresia].

Aiming at depicting the advantages of chick embryo as a model of fetal surgery we report on our experience of 402 operations carried out in an attempt to induce fetal intestinal obstruction. We have used fertile domestic hen (gallus gallus) eggs incubated at 37.5 degrees with 80% humidity and turned every hour. At the 12th day of incubation we coagulated, after exposing the umbilical cord, a small bowel loop in the physiologic umbilical hernia through a 1 cm-wide opening in the shell which was then sealed with plastic sterile adhesive. After sacrifice at the 15th day of the 76 surviving embryos (19%) we found type I intestinal atresia with localized meconium peritonitis and dilated proximal loop in 46 cases. In 3 out of them there was, like in some human newborns with intestinal obstruction, increased amount of bile-stained amniotic fluid. Both macroscopic and microscopic findings were identical to those usually found in human atresia and in that experimentally induced in fetus of other animal species. We firmly believe that our model is as good as any other for this purpose and, at the same time, it is cheaper and easier to handle.

Animals↗