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Biomedical subjects

C L Berry

Publications and source records attributed to C L Berry.

At least 19 recordsLinked to original sources
PubMed1992

Myoendothelial contacts in the thoracic aorta of rat fetuses.

There is increasing documentation of the presence of endothelial-smooth muscle communication in both small and large arteries. We have found that morphological evidence of these contacts appears early in development. Intimate contacts between endothelial and muscle cells in the thoracic aorta of normal rat fetuses have been studied with transmission electron microscopy. These myoendothelial contacts were seen in the form of cytoplasmic projections passing through fenestrae in the elastic lamellae. Most of these cell processes seem to arise from the muscle cells and they usually have a club-shaped configuration. The specific nature of the cell-cell contact was predominantly via simple appositions with an intercellular space of 6-15 nm. Myoendothelial contacts are potential sites for electrical and metabolic communication between elements of the intima and media, ensuring that the vessel wall works as a unit. The demonstrated necessity of intact endothelium for smooth muscle cell response to load may depend on this type of contact.

Animals↗
PubMed1992

Myoendothelial contacts in arteriolosclerosis.

Human renal biopsies were examined electron microscopically to investigate close contacts between endothelial and smooth muscle cells in small arterioles. These myoendothelial contacts were seen in the form of cytoplasmic projections passing through fenestrae in the basal lamina. Most of these cell processes seem to arise from the endothelial cells. In the control vessels, the separation between the endothelial cells and smooth muscle cells of the tunica media is 0.09-0.27 microns. With arteriolosclerosis there is an increasing separation between the elements of the intima and the media, from 1.0 to 2.42 microns. In spite of this increasing separation, myoendothelial contacts maintain an intercellular space of 10-15 nm, as observed in the control vessels. At 2.42 microns of separation, the amount of extracellular material accumulated is such that the cells can no longer keep in contact. Break up of the myoendothelial contacts may be responsible for impairment of communication between the tunica intima and media in the vessel wall in arteriolosclerosis.

Aged↗
PubMed1992

The development of an in-vitro perfusion system for studies on cultured cells.

The design and use of a perfusion system, using a modified flow chamber for studies on cultured animal cells, is described. Rat thoracic aorta smooth muscle cells were isolated by an explant method and grown on Thermanox coverslips. These were introduced into the flow chamber. A flow rate of 25ml/min and a shear stress of 14.6 dynes/cm2 (12 dyne = 10 microN) (both within physiological limits) were maintained. Cells remained attached to the coverslips after 8h of perfusion with culture medium. The effect of exposing rat smooth muscle cells to the cardiovascular toxin, allylamine, is also described. The components of the system are routinely available, simple to clean, easy to assemble and sterilize. The incorporation of an in-line sensor that monitors pH, PO2, PCO2 and temperature ensures that the perfusion conditions remain within physiological limits. Automation means that minimal supervision is required. This system provides a potential mechanism in which cultured vascular cells may be perfused under controlled haemodynamic conditions, and their response to a cytotoxin may be evaluated.

Allylamine↗
PubMed1991

UK clinical research.

Explore the source record for details and available documents.

National Health Programs↗
PubMed1991

Intercellular contacts in the media of the thoracic aorta of rat fetuses treated with beta-aminopropionitrile.

Beta-aminopropionitrile (BAPN) alters the scleroproteins of the arterial media in a way which permits an increase in the stress (force/unit area) applied to smooth muscle cells at a given pressure. Pregnant Sprague-Dawley rats were treated with BAPN and the thoracic aortas of exposed fetuses were studied by electron microscopy and image analysis. Transmission electron microscopy of the media of the thoracic aorta revealed that the types of intercellular contacts seen in the controls and in the BAPN group were intermediate junctions (IJs), nexus junctions (NJs), simple appositions (SAs), and interdigitations (Ids) as in adult vessels. The BAPN-treated animals showed an increased density of IJs, SAs, and Ids when compared with controls but the NJs demonstrated no change. Load-sensitive intercellular contacts have been considered to be the major route by which stress is applied across cells, and the increased number in the BAPN group probably represents a response of the vessel wall to increased tangential tension.

Aminopropionitrile↗
PubMed1991

Purkinje cell toxicity of beta-aminopropionitrile in the rat.

Compounds causing neurolathyrism are putative aetiological agents in neurodegenerative disorders including amyotrophic lateral sclerosis. beta-Aminopropionitrile (BAPN) is one such compound. We have administered this lathyrogenic agent at a dose of 1 g/kg by the intraperitoneal route in experiments in adult Sprague-Dawley rats during a period of 10 weeks. The rats developed marked kyphoscoliosis, ataxia with paralysis and muscle wasting of the hind limbs. Vacuolation and loss of Purkinje cells developed, but no anterior horn cell degeneration was noted. Immunohistochemical studies of phosphorylated neurofilaments and the 72 kDa heat shock protein were normal and no intraneuronal ubiquitinated inclusions were seen. High-dose intraperitoneal BAPN in the rat causes Purkinje cell changes, but no other central nervous system abnormalities.

Aminopropionitrile↗
PubMed1991

Effects of hypertension on the intercellular contacts between smooth muscle cells in the rat thoracic aorta.

A qualitative and quantitative study was made of the contacts between muscle cells in the media of the thoracic aorta of hypertensive and normotensive Sprague-Dawley rats. In ultrathin sections, the type and number of contacts per 100 microns cell perimeter and per 100 cell profiles were determined using an image analysis computer. The intercellular contacts in both groups were in the form of simple appositions, interdigitations, intermediate junctions and nexus junctions. In the hypertensive group, there was a reduction in the number of simple appositions and intermediate junctions, but the nexus junctions (which provide intercellular communication) were increased in density. Interdigitations demonstrated no change. Decreased intercellular cohesion may play an important role in the mechanisms by which hypertension predisposes degeneration of the media with progression to ectasia, aneurysm formation and dissection.

Animals↗
PubMed1990

Effect of age on the in vitro reflection coefficient of the aortoiliac bifurcation in humans.

The local reflection coefficient (r) at the aortoiliac junction was estimated in vessels removed at autopsy from 15 females and 31 males aged 2 months to 88 years by calculating the characteristic impedance (Zc) of the abdominal aorta and the two common iliac arteries. Zc was evaluated for each vessel by measuring cross-sectional area from radiographs and propagation velocity of an isolated pressure impulse generated by a solenoid-driven piston connected to the distal end of the abdominal aorta, and detected at several sites a known distance from the junction. Attenuation coefficients in the aorta were estimated from the peak amplitude of the impulse at these several sites. We observed significant decreases with age in abdominal aortic attenuation coefficient (gamma = 0.053-5 x 10(-4) age [yr], r = -0.42, p less than 0.005), and the area ratio (AR) of the junction (sum of the iliac cross-sectional areas/aortic cross-sectional area) (AR = 0.93-0.002 x age [yr], r = -0.31, p less than 0.05). Bifurcation angle (Angle) and aortic propagation velocity (caorta) increased significantly (angle = 40.2 + 0.26 x age [yr], r = 0.41, p less than 0.01; caorta (ms-1) = 7.59 + 0.175 x age [yr], r = 0.69, p less than 0.0001). No significant association between age and iliac propagation velocity was found. On the basis of area measurements alone, it has been argued that the observed decrease in area ratio with age causes r to become more positive. The lack of age-related changes in iliac propagation velocity (and hence stiffness), an observation confirmed by most of the few reports in the literature, and the large increase in abdominal aortic stiffness, however, greatly outweighed the area ratio changes and caused a significant decline in reflection coefficient from +0.3 in early life to -0.3 in old age. (Reflection coefficient = 0.30-0.0065 x age [yr], r = -0.68, p less than 0.0001). Between the ages of 30 and 60 years, its absolute value was less than 0.1, confirming in vivo work on subjects within this age range. In children, a significant positive reflection at the distal end of the aorta will amplify the pulse wave in this region. As this vessel becomes stiffer with increasing age, amplification will increase, whereas the increasingly negative value of r will partially offset this rise, reducing pulse pressure on either side of the junction.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Cytomegalovirus and human herpesvirus-6 in sudden infant death syndrome: an in situ hybridization study.

Thirty lung, spleen, and thymus sections and four lymph node sections from 40 sudden infant death syndrome (SIDS) cases were probed with biotinylated DNA probes specific for human herpesvirus-6 (HHV-6) and cytomegalovirus (CMV). Control material gave a strong, distinct signal with little or no background staining and no cross-reactivity. No staining was found with the SIDS material. We find no evidence to implicate an overwhelming infection by either virus in SIDS.

Cytomegalovirus Infections↗
PubMed1989

Neuropathology of the brain in HIV infection.

The brains of 26 patients infected with the human immunodeficiency virus (HIV) were examined post mortem. All patients were men, aged 20-67 years (mean 38.8). 13 (50%) were homosexual, 3 (12%) were bisexual, 8 (31%) were haemophiliac, 1 was both an intravenous drug addict and homosexual, and 1 denied belonging to any risk group. Only 3 (12%) brains were normal, whereas 23 (88%) showed abnormalities that varied in severity and complexity. 11 were affected by more than one disease. In addition to neoplasms, opportunistic infections, and vascular lesions, 6 cases of HIV encephalitis were found, characterised by multinucleate giant cells which indicate the presence of HIV. Microglial-macrophage nodules (nodular encephalitis) occurred in 5 cases. Cerebral pathology differed between risk groups: all 6 patients with HIV encephalitis were homosexuals, whereas vascular lesions were more common in haemophiliacs. These observations have fundamental implications for clinical practice and indicate the importance of neuropathological examination in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Contact relationships between vascular smooth muscle cells: an in vivo and in vitro study.

Cell/cell contacts in the intact media of the rat thoracic aorta and inferior vena cava, and in cultured smooth muscle cells from these vessels have been quantified in order to determine whether their density and their type can be correlated with the differences in load at these two sites. The type and number of contacts per 100 microns of cell perimeter and per 100 cells were determined with a semi-automatic image analysis system. In all cases there was a predominance of simple appositions; intermediate junctions, interdigitations, and nexus junctions were less frequently observed. There were more cell contacts of each type in the intact arteries than in the intact veins. In cell cultures, all types of cell contacts were increased but the proportion of load bearing types was reduced.

Animals↗
PubMed1989

Nexus junctions between vascular smooth muscle cells in the media of the thoracic aorta in normal and hypertensive rats. A freeze-fracture study.

Freeze-fracture electron microscopy and image analysis have been used to study the nexus junctions (NJ) between smooth muscle cells in the media of the thoracic aorta of normal and hypertensive Sprague-Dawley rats. The NJ found in both groups revealed particles on the P-face and depressions or pits in the E-face. Within each face, particle- or pit-free areas were identified in some junctions. NJ are usually surrounded by a narrow area devoid of particles and in certain fracture planes a close relationship of NJ with smooth endoplasmic reticulum was seen. Larger and more irregular NJ were found in the hypertensive group than in the controls. The differences observed in the hypertensive animals may be associated with an increase in tangential tension in the vessel wall.

Animals↗