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Biomedical subjects

H Martinez

Publications and source records attributed to H Martinez.

At least 73 records · Page 4Linked to original sources
PubMed1985

The biphasic opening of the blood-brain barrier to proteins following temporary middle cerebral artery occlusion.

The behavior of the blood-brain barrier (BBB) was studied in cats following release after 1-h middle cerebral artery (MCA) occlusion. The regional cerebral blood flow (rCBF) was determined by hydrogen clearance method in the caudate nucleus and the cerebral cortex. The BBB was assayed with Evans blue (EB) tracer and by immunohistochemical peroxidase-antiperoxidase (PAP) method. Following release of MCA occlusion, there were two openings of the BBB, separated by a refractory period. The first opening, occurred shortly after recirculation; this was associated with rCBF below 15 ml/100 g/min during the ischemic period and a pronounced reactive hyperemia promptly following release of MCA occlusion. A refractory period of the BBB was indicated by the absence of EB leakage in cats injected with the tracer 30 min before killing at 3 h after recirculation, although the rCBF values in these animals were even lower (6 +/- 1 ml/100 g/min) during occlusion, and all of them showed a pronounced hyperemia after recirculation. The occurrence of the previous BBB opening in these animals was confirmed by the PAP staining. The second opening of the BBB was observed at 5 and 72 h after recirculation in cats which were injected with EB 30 min before killing, and which showed rCBF below 15 ml/100 g/min during occlusion, followed by a pronounced reactive hyperemia. No EB extravasations were observed at any time in cats in which the rCBF during occlusion was above 15 ml/100 g/min and which failed to show a marked reactive hyperemia.

Animals↗
PubMed1985

Plasma lipids, apolipoproteins A and B in maternal and umbilical vessels in term pregnancies.

Total cholesterol (TC) high density lipoprotein cholesterol (HDL-C), triglycerides (TG), apolipoprotein A (Apo A) and apolipoprotein B (Apo B) were measured in 40 plasmas from term pregnant women at vaginal delivery. Blood samples were obtained simultaneously from the maternal vein, umbilical artery and umbilical vein. The mean values of lipids and apolipoproteins were significantly (P less than 0,0001) lower in umbilical vessels than in the mother. TC, HDL-C, TG and Apo B were significantly (P less than 0,0005) higher in umbilical vein than in umbilical artery. No significant differences in Apo B levels were found between umbilical vein and artery.

Apolipoproteins A↗
PubMed1983

Differential diagnosis between ventriculitis and fourth ventricle cyst in neurocysticercosis.

The fourth ventricle is frequently affected in patients with cysticercosis of the central nervous system, due either to a large cyst occluding the cavity or to granular ependymitis (ventriculitis) as a consequence of diffuse inflammation within the intraventricular and subarachnoid spaces. In some cases, the differential diagnosis between these two forms of neurocysticercosis is difficult to make, even after special radiological procedures. It is important to establish the correct diagnosis, since a surgical approach is beneficial only when the fourth ventricle is obstructed by a large cyst. In this paper, the clinical differences between fourth ventricle cysts and ventriculitis are presented in 16 patients with neurocysticercosis who were subjected to surgical exploration of the posterior fossa. Patients with a large cyst occluding the fourth ventricle had a short evolution of signs and symptoms, Bruns' syndrome, and discrete or no inflammatory reaction in the cerebrospinal fluid (CSF). Patients with ventriculitis generally had a longer duration of signs and symptoms, Parinaud's syndrome, a consistently positive complement fixation test to cysticerci, and more cells and proteins in the CSF. The clinical picture and ancillary studies can give the precise diagnosis in most patients before surgical exploration is performed.

Adolescent↗
PubMed1980

[Genetic variability of colonies of noninbred Cubavet and CENIC laboratory mice from the Republic of Cuba].

Genetic structure of non-inbred Cubavet and CENIC mice colonies was investigated for three loci of hair colouring (A, B, D), for potential fertility and embryo mortality. Mice colonies are polymorphis in three hair colour determining loci. Alleles rates are: a -- 0.17--0.36; b -- 0.21--0.26; d -- 0.07--0.17. Both colonies reliably differ in colour genotype distribution (p less than 0.001). There are also some differences in the number of live embryos, yellow bodies and postimplantation mortality (p less than 0.05--0.001). The data obtained allow to control the stability of genetic structure of the population for a long time.

Alleles↗