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J Sahuquillo-Barris

Publications and source records attributed to J Sahuquillo-Barris.

4 recordsLinked to original sources
PubMed1998

Morphological characteristics and distribution pattern of the arterial vessels in human cerebral cortex: a scanning electron microscope study.

BACKGROUND: The human cerebral cortex is supplied by vessels that arise from the pial arteries. These vessels give rise to a dense vascular network that is highly interconnected. Cortical arteries have been classified in different categories. Both their angioarchitectonic pattern and anatomical structures involved in their regulation are not fully understood. METHODS: Twelve fresh human brains were studied by scanning electron microscopy of vascular corrosion casts. RESULTS: Four types of arterial vessels in the cerebral cortex--short, middle, long, and transcortical--were identified. The cortical vascular network was formed by several interconnected clusters of vessels, which were arranged in four vascular layers parallel to the pial surface and characterized by different vascular densities. The greatest vascular density corresponded to the middle and deep vascular layers. Circular constrictions were found at the origin of cortical arteries and at their branching sites, probably related to vascular sphincters. Connections between cortical arteries were observed at their initial course. Plastic strips, occasionally related to constrictions, were observed around both middle and long cortical arteries. Other plastic structures, morphologically similar to pericytes, were found around capillary vessels. CONCLUSIONS: The blood supply to the human cerebral cortex depends on the short, middle, and long cortical arteries, which give rise to a highly anastomosed capillary network. There exist vascular connections between pial arteries and occasionally between cortical arteries. Blood flow autoregulation is probably mediated by smooth muscle cells at the arteriolar level and by pericytes at the capillary level, through endothelial connections.

Adult↗
PubMed1998

Perivascular structures in corrosion casts of the human central nervous system: a confocal laser and scanning electron microscope study.

Scanning electron microscopy (SEM) of microvascular corrosion casts revealed perivascular structures that resembled smooth muscle and pericyte cells. Although these structures have been studied in widely different experimental contexts, their origin, function, and distribution pattern in different tissues are not understood. Microvascular corrosion casts from 15 fresh human brains and 20 lumbar spinal cords were studied by SEM. In five cerebral hemispheres a fluorescent resin was injected in order to study the vascular bed by confocal laser scanning microscopy (CLSM). Microvascular casts showed two perivascular structures on their surfaces: plastic strips, which formed a muff around arteriolar vessels, and pericyte-like structures that were present around the capillary network. Their morphological characteristics and distribution were similar to those of smooth muscle cells and pericytes, respectively. The SEM study showed that these structures were not tightly joined to the cast surface, but were connected to the vascular cast by narrow plastic connections. The CLSM showed that the resin invaded the subendothelial space, thus giving rise to these structures. Perivascular structures associated with arteriolar and capillary vessels appear to represent smooth muscle cells and pericytes. They are formed by the passage of the resin to the subendothelial space, probably through weak endothelial cell junctions. The effusion of resin into the subendothelial space may represent evidence for the structural basis of myocyte and pericyte cell control. Chemical communication by substances released locally or transported to these cells through these junctions may regulate their functions, allowing them to regulate blood flow.

Adult↗
PubMed1988

Acute subdural hematoma and diffuse axonal injury after severe head trauma.

The association of acute subdural hematoma (SDH) and diffuse axonal injury has received little attention in the literature. The authors report the clinicopathological findings in six patients who died of severe head injury in whom computerized tomography revealed acute SDH as the predominant lesion. All patients were injured in road traffic accidents and lost consciousness on impact. The mean total contusion index was 17.4 and sever contusions were seen in only two cases. All patients presented histological criteria of intracranial hypertension (pressure necrosis focus in one or both parahippocampal gyri). Hypoxic brain damage was evident in the postmortem examination of three patients. In three cases, macroscopic hematic lesions were observed in the corpus callosum. All patients had widespread axonal retraction balls disseminated in the white brain matter. Three patients who survived for more than 11 days had microglial clusters. In some patients with a head injury, acute SDH may be only an epiphenomenon of a primary impact lesion of variable severity: that is, a diffuse axonal injury. In these cases, the final outcome is fundamentally dependent on the severity of the subjacent diffuse axonal injury.

Acute Disease↗