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Biomedical subjects

W Goossens

Publications and source records attributed to W Goossens.

At least 55 records · Page 3Linked to original sources
PubMed1986

Erythrocyte 2,3-diphosphoglycerate and serum enzyme concentrations in trained and sedentary men.

The acute effect of exercise on the intraerythrocyte 2,3-diphosphoglycerate concentration and on various serum enzymes and some related variables was investigated in 14 male athletes before and after a 50-min cross-country run and compared at rest to 15 sedentary subjects. Compared to the sedentary subjects, the athletes had higher resting levels of serum creatine phosphokinase, plasma myoglobin, and renin substrate but had a lower plasma renin activity. The red blood cell 2,3-diphosphoglycerate concentration increased after exercise in the runners and was not different at rest between the athletes and the sedentary subjects. Our data therefore suggest that the resting plasma renin activity is reduced in athletes when compared to sedentary subjects. Training seems however not to alter the resting level of 2,3-diphosphoglycerate in the red blood cells.

2,3-Diphosphoglycerate↗
PubMed1985

Prolonged survival of allogeneic corneal grafts in rabbits treated with topically applied cyclosporin A: systemic absorption and local immunosuppressive effect.

The modes of action of topical cyclosporin A were studied in rabbits. Immunorejection of corneal allografts was provoked by placing the grafts eccentrically, in contact with the limbus. Topical application of cyclosporin A five times daily for 28 days prevented the rejection of corneal allografts. All grafts were rejected in the control animals. The seven rabbits of the cyclosporin A group were subsequently treated for six months with a lower dosage of cyclosporin A 1%. In six rabbits the graft remained clear. One rabbit treated with two drops a day showed an allograft reaction that could be suppressed by increasing the dosage. After six months, discontinuation of the therapy resulted in rejection of all grafts within four weeks. Cyclosporin A could be detected in the plasma and aqueous humour of both eyes at the end of the treatment, raising the question whether the immunosuppressive effect of topically applied cyclosporin A was due to local or systemic action. Cyclosporin A 1% was therefore applied to the fellow eye five times daily following transplantation, and this treatment, producing similar plasma levels of cyclosporin A, failed to delay the rejection of eccentric corneal allografts. Consequently the suppression of the allograft rejection by topical cyclosporin A is primarily a local immunosuppressive effect, though systemic influence is not ruled out.

Administration, Topical↗
PubMed1984

Lens wound healing and cataractogenesis in a pigmented eye.

Light and electron microscopy and slitlamp microscopy were used to follow the development and partial repair of injury-induced cataract in the lens of the pigmented eye of the grey squirrel. These processes proceed in much the same way as in previously-studied albino rodents and rabbits in spite of invasion of the lens opacity by pigmented cells in the squirrel eye. Epithelial and capsular regeneration and lens fiber repair occur rapidly and apparently independently from the accumulation of pigmented cells, fibroblasts and collagen in the wound outside the lens epithelial layer. Using morphological criteria, some of the pigmented cells in the lens wound are identified as iris stromal melanocytes and pigmented epithelial cells; this is consonant with the slitlamp observations of streams of pigmented cells extending from the iris to the lens wound. The role, if any, of the pigmented cells in lens wound healing is unknown.

Animals↗
PubMed1984

In situ localization of S1-labeled actin filaments in chick lens epithelial cells.

The actin filaments in the lens epithelial cells of three-day and eight-day post-hatched chicks have been labeled in situ with myosin subfragment 1 (S1). Labeling was accomplished by injuring the lens transcorneally with an ultramicroneedle 5 min or 24 hr before detergent treatment and incubation in S1. A band of filaments found at the epithelio-fiber junction in normal, uninjured chick lens is labeled in the 5 min and 24 hr injury. A subcapsular labeled band is found only in the 24 hr injury, and may be the result of a healing process.

Actins↗
PubMed1984

Racial differences in intracellular concentration and transmembrane fluxes of sodium and potassium in erythrocytes of normal male subjects.

Erythrocyte concentrations and fluxes of sodium and potassium were investigated in normal black and white male subjects. Erythrocyte sodium concentration was significantly elevated in blacks compared to whites. In single regression analysis erythrocyte sodium concentration was inversely related to the ouabain-sensitive 86Rb-uptake and to the frusemide-sensitive sodium efflux. After adjusting for race, only the relationship between the erythrocyte sodium concentration and the Na+, K+-ATpase pump activity persisted. The sodium-lithium countertransport system was also depressed in the black subjects. No significant difference was observed in erythrocyte potassium concentration between blacks and white. It is probable that, in blacks the decreased active influx of potassium through the sodium-potassium pump was to some extent counter balanced by a reduced efflux of this cationic mediated by the depressed cotransport system. There was no difference in cationic concentrations and fluxes of sodium and potassium between blacks bearing and not bearing haemoglobin S.

Adult↗
PubMed1984

An ultrastructural study of fixation artifacts in lens epithelium.

The conditions providing for optimal preservation of the ultrastructure of the lens epithelium of embryonic and young chicks were sought, especially with regard to avoiding fixation artifacts and to enhancing the lens cytoskeleton. The optimal fixative/buffer solution for these purposes was found to consist of 2% glutaraldehyde in 0.05M phosphate buffer containing 0.2% tannic acid and 0.002% CaCl2, pH 7.2, whose total osmolarity is about 340 mOsm, and postfixation in 1% osmium. As the osmolarity was increased by use of 0.075M or 0.1M phosphate buffer, intercellular spaces and myelin-like figures appeared along the cell membranes of the epithelial cells and superficial cortical fibers. As the osmolarity was decreased, using 0.02M phosphate buffer, plasma membranes became flaccid and interrupted, nuclei underwent severe shape changes, and the cytoplasm became electron-lucent. Delays of 30 minutes or one hour before fixation caused swelling of cytoplasmic organelles and the nuclear envelope. Primary fixation in osmium resulted in interrupted cell membranes and in swollen organelles. Many of these artifacts seen in the superficial chick lens, produced merely by manipulating the tonicity or the time of fixation after death, have been previously attributed in the literature to cataractous or aging changes. Based on the present findings caution in interpreting electron micrographs of pathologic changes in lens is urged.

Animals↗
PubMed1983

Blood neutrophil function in primary myelodysplastic syndromes.

Ten different tests of blood neutrophil function were studied in 20 patients with primary myelodysplastic syndromes (PMDS). The patients were selected according to the new diagnostic criteria for PMDS of the FAB-cooperation group. Impairments of granulocyte functions were found in all patients. Moreover, several steps in the mobilization of granulocytes at the site of injury seemed to be affected: decreased adhesion (P less than 0.05), deficient chemotaxis (P less than 0.05), decreased enzyme content (P less than 0.001), 'slower' chemiluminescence (P less than 0.005), decreased phagocytosis (P less than 0.05) and impaired microbicidal capacity (P less than 0.025). No significant correlation between disease category and severity of granulocyte dysfunction was discerned, though an increasing number of blasts was associated with more severe granulocytic disability. Results in seven patients with abnormal karyotypes were not significantly different from 13 others with normal karyotypes. Our results indicate that defects in blood neutrophil function are a common feature in PMDS and might account for the increased frequency of infection in these patients.

Adolescent↗
PubMed1983

Effect of beta-blocking drugs on red cell adhesive and rheological properties.

Abnormal cell-cell interactions at the vessel wall play an important role in the development of microvascular occlusions. Since beta-blocking drugs have been implicated in the long-term and short-term prevention of myocardial infarction, we investigated the possibility that these drugs might exert their action by interfering with red cell-endothelial interactions. 51Cr-labeled, washed erthrocytes were added to confluent monolayers of cultured human vascular endothelial cells. After incubation at 37 degrees C, the nonadherent red cells were removed by sequential washing. When red cells were pretreated by cardioselective or noncardioselective beta-blocking drugs (e.g., metoprolol and propranolol), significantly fewer erythrocytes remained adherent to the endothelial monolayers after repeated washing. Pretreatment of the endothelium did not result in decreased adherence, indicating that the inhibitory action of beta-blockers is exerted on the red cell itself. The specificity of red cell-endothelial interactions is illustrated by the finding that erythrocytes adhere significantly less to plastic surfaces. In parallel studies, we have shown that beta-blockers significantly both diminish erythrocyte viscosity and increase erythrocyte deformability. The precise mechanisms of cellular action by which beta-blockers exert these actions remain unknown. Differences in beta-receptor subtypes do not seem to be involved, but complex metabolic changes leading to alterations in physiological properties of the red cell membrane cannot be excluded. Finally, our results suggest that the presumed beneficial effects of beta-blockade in various prethrombotic conditions (e.g., hypertension, angina pectoris, reinfarction) may be partly due to the interference of these drugs with the normal and abnormal adhesive and rheological properties of human erythrocytes.

Adrenergic beta-Antagonists↗
PubMed1981

Human cataracta complicata. Clinicopathologic correlation.

Complicated cataracts of the posterior subcapsular zone may be associated with a number os systemic conditions. Cataracts from patients with retinitis pigmentosa, Turner's syndrome, myotonic dystrophy, or those who were taking corticosteroids were examined clinically and pathologically after intracapsular cataract extraction. Two major types of posterior subcapsular opacities were observed: one type had multiple vacuoles, while the other type was a more solid appearing (plaque-like or snowball) opacity clinically. The predominant morphologic counterpart (by light and electron microscopy) of the vacuolar opacity is liquefactive necrosis with aberrantly migrated epithelia cells growing into the cataract. In the plaque-like or snowball opacity, the lens fibers are generally disorganized into round globules. The clinical significance is that the vacuolar-liquified posterior subcapsular cataract may be more easily removed by extracapsular methods than the plaque-like opacity; however, the proliferative cells in the vacuolar type are probably the source of an after-cataract membrane that may require discussion.

Adrenal Cortex Hormones↗
PubMed1980

Ultrastructure of human cataract in retinitis pigmentosa.

A second ultrastructural study of retinitis pigmentosa cataract showed differences from the previous case with respect to sex, age of cataract onset, age at time of cataract extraction, and mode of inheritance of retinitis pigmentosa. Furthermore, the cataract in the present study was limited clinically and preponderantly ultrastructurally to the posterior subcapsular area, which is typical of the location of cataracts associated with retinitis pigmentosa. The cataract was characterized by severe lens fiber disorganization, resulting in intricately distorted membrane configurations and varying cytoplasmic densities; however, "figure eight" configurations as noted in the other report were not observed. Aberrantly migrated epithelial cells were distributed unevenly in the posterior subcapsular zone. New capsular basement membrane, not mentioned in the other report, was conspicuous in our case. Thus, retinitis pigmentosa cataract may have diverse ultrastructural alterations.

Adult↗
PubMed1977

Ultrastructure of traumatic cataractogenesis in the frog: a comparison with mouse and human lens.

Normal and needle-punctured lenses of Rana pipiens were examined with the electron microscope in order to characterize the sequence of ultrastructural changes that follow the injury over a 5-month period. Results were compared with those obtained previously in experimentally injured mouse and accidentally injured human lenses. The normal adult frog lens was found to have a morphology similar to that of mammalian lenses. As in the human, frog lens epithelial cells contained scattered microfilaments and were connected by desmosomes and gap junctions. They differed from mouse cells, which had been shown to lack desmosomes and to have microfilaments organized into dense bundles. These differences are postulated to be related to the degree of accommodative deformation of the lens displayed by these species. After injury, cellular debris and fibrin, accumulated in the wound, were phagocytized by extrinsic cells derived from the blood and ocular tissues. Leucocytes, pigmented cells and fibroblasts remained in the wound for eight weeks, along with epithelial cells which proliferated and migrated from the wound margins.Epithelial cells showed an increase in those organelles associated with protein synthesis and transport, and in microfilaments. In cataractous lenses, epithelial cells showed changes in matrix, and lens fibers became organized into smaller, denser compressed units. At five months, considerable healing had taken place, but localized opacities persisted in many frog lenses.

Animals↗
PubMed1975

Ultrastructural studies of traumatic cataractogenesis: observations of a repair process in mouse lens.

Lenses of CFI mice were studied with the transmission electron microscope at frequent intervals through 13 months following a transcorneal needle injury to the lens. While this kind of injury causes a high incidence of traumatic cataract in the human and frog, it elicits a repair process in the mouse lens whereby the damaged capsule, epithelium and lens fibers are rapidly renewed and permanent lens opacity seldom occurs. Ultrastructural changes in lens epithelial cells adjacent to the wound, which precede and accompany localized cellular proliferation and production of new capsule, involve a rapid increase or enlargement of organelles associated with protein synthesis and assembly. The capsule and epithelium are repaired within a couple of months. Cortical lens fibers in the wound area undergo conformational changes into smaller, ordered arrays of "membranous sacs". These are replaced within a week by normal appearing lens fibers. There is minimal degeneration or hyperplasia noted, and except for a few fibroblastic cells on the lens surface, little evidence remains of the injury by two months. Ultrastructural differences between mouse and human lens, such as presence or absence of dense bundles of microfilaments and desmosomes are considered in relation to lens shape and tension, and susceptibility to injury-induced cataract.

Animals↗
PubMedDate not supplied

Complement activation and adult respiratory distress syndrome during intermittent flow apheresis procedures.

We observed complement (C) activation during intermittent flow apheresis procedures (Haemonetics model 30) in four subjects, two of whom developed adult respiratory distress syndrome (ARDS). Actual C3 conversion during apheresis was illustrated by the finding of significantly elevated C3d levels (p less than 0.05) and of significantly increased alpha-1-antitrypsin/C3 ratios (p less than 0.05) in postapheresis serums. Similarly, marked granulocyte aggregating activity was found in these serums, indicative of the generation of significant amounts of the C-derived anaphylatoxin, C5a or C5a desarginine. A mean decrease of 59.75 percent in neutrophil count during the four procedures suggested sequestration of aggregated granulocytes in the pulmonary vasculature. Moreover, granulocytes activated by apheresis serums induced significant 51Cr leak from cultured human endothelial cells is vitro (p less than 0.001). We conclude that inflammatory C components produced during apheresis procedures may provoke granulocyte aggregation and embolization, leading to plugging of the pulmonary vasculature, and that apheresis-activated granulocytes may induce endothelial cytotoxicity, leading to the capillary leakage syndrome, characteristic of ARDS. Individual variability in C5a generation capacity or alterations in normal C5a clearing mechanisms may account for the low incidence of clinical C activation and true ARDS during apheresis. In these instances, high-dose steroids, which interfere with granulocyte-C interactions, may be beneficial.

Adult↗