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Biomedical subjects

J Oliver

Publications and source records attributed to J Oliver.

At least 145 records · Page 8Linked to original sources
PubMed1990

Corneal endothelial permeability after anterior chamber silicone oil.

One of six silicone oils, differing in both viscosity and manufacture, was infused into the anterior chambers of rabbit eyes. Polydimethylsiloxane oil, 5000 cps, caused an increased corneal endothelial permeability to inulin and dextran at 24, 96, and 168 hours after placement into the eye. Intraocular pressures were slightly elevated in the experimental eyes, compared with contralateral controls, at 24 and 144 hours after infusion. The effects of five other oils on corneal endothelial permeability were examined 168 hours after infusion. All oils increased permeability and caused thinning of endothelial cells, together with the appearance of a retrocorneal membrane, except Dow Corning Medical Fluid 360. The results indicated that contact of most silicone oils with corneal endothelium rapidly induces physiologic and morphologic changes.

Animals↗
PubMed1990

A contiguous network of dendritic antigen-presenting cells within the respiratory epithelium.

This study utilises a simple technique to section airway epithelium in a plane parallel to the basement membrane, thus providing a unique plan view of the intra-epithelial cell populations. Immunoperoxidase staining of these tissue sections for class II major histocompatibility complex Ia antigen reveals a virtually contiguous network of Ia-positive dendritic cells (DC) within the epithelium. These DC are shown to be capable of binding inhaled antigens in vivo in a form suitable for presentation to T cells. The strategic location of these cells and the fact that they account for virtually all staining in the airway epithelium during the steady state is convincing evidence that the DC network functions as the 'first line of defence' in surveillance for inhaled antigens and further suggests a major role for the intra-epithelial DC in allergic and infectious disease(s) in the respiratory tract.

Animals↗
PubMed1990

Effects of silicone oils on corneal endothelial permeability.

Silicone oils, varying by viscosity and manufacturer, were infused into rabbit anterior chambers. Polydimethyl-siloxane oil, 5000 cps, increased corneal endothelial permeability to inulin (mw 5000) and dextran (mw 60000) when measured in vitro at 1, 4 and 7 days after ocular infusion. The effects of five other oils were measured at 7 days after infusion. Four of the oils increased endothelial permeability and induced similar morphological changes. Dow Corning Medical Fluid 360 had no effect on either permeability or morphology of the endothelium. These results show that contact of most silicone oils with corneal endothelium rapidly induces physiological and morphological changes. If these oils, when used as a retinal tamponade, gain access to the cornea they should be removed quickly to avoid the rapid initiation of physiologic changes.

Animals↗
PubMed1990

[Right-sided infectious endocarditis. Experience with a series of 35 patients].

From 1978, 35 patients with right-sided endocarditis were treated at our hospital. There were 25 male and 10 female patients, with ages ranging from 14 to 77 years. The cause was intravenous drug abuse in 27 cases. Positive blood cultures were obtained in 29 cases, isolating staphylococcal organisms in 26 of them. Two-dimensional echocardiography was performed in 30 patients, confirming the diagnosis in 27 of them (90%). Vegetations were found in 25 patients and perivalvular abscess was seen in 4 patients. The management was medical only in 32 patients. Three patients were operated on because of failure to control pyrexia and heart failure, performing total tricuspid valvectomy in two, and only partial in the third one. All the 3 patients had perivalvular tricuspid abscess. There were 2 hospital deaths (5.7%), because of septic shock in drug abusers, one of them after a tricuspid valvectomy. In our experience, right-sided endocarditis is mainly associated with drug abusers and staphylococcal organisms. Two-dimensional echocardiography plays an important role in the diagnosis of this entity. In our series the size of vegetations does not play a role in selection of surgical candidates. The presence of perivalvular abscess was the only predictive factor for surgery. Only a few patients do not respond to medical therapy. In those cases the elective surgical procedure in our criterion and in our patients is tricuspid valvectomy without valve replacement, or if possible, the use of reconstructive or reparative approaches.

Adolescent↗
PubMed1990

[Infective endocarditis. Medicosurgical experience in a series of 137 patients].

We have reviewed our 1978 to 1987 experience in the treatment of 137 patients with 145 episodes of Infective Endocarditis. In 55 episodes the infection involved a valvular prosthesis. Positive blood cultures were obtained in 72.7%, with clear preeminence for staphylococcal organisms. Renal disfunction was associated in 41.8% of the cases and periprosthetic-leak in 40% of them. Eight patients died without surgery, five cases were cured by medical treatment alone, and 42 cases were operated, most of them because refractory heart failure. Surgical mortality was 15 cases (35.7%), with statistical significance within the early prosthetic valve endocarditis group, in which in turn was significantly greater the incidence of non-streptococcal germs, renal disfunction and periannular abscesses. The mean late follow-up was 47.6 months, including 88.8% of the surgical survivors, with a survival rate of 64.1%, being most of patients in a good functional status. In 90 episodes the infection involved a native valve, with about 40% of the cases in drug abusers. Positive blood cultures were obtained in 77.7% of the cases, with slight preeminence of staphylococcal germs. Renal dysfunction was associated in 16.6% of the cases. In 41 episodes were used only medical therapy, involving 30 of them the right side, with a death in this group. The treatment was surgical in 49 episodes, 45% of them in order to correct residual valve lesions.

Adolescent↗
PubMed1989

[Asymmetric septal myocardial hypertrophy associated with pheochromocytoma: reversibility of cardiopathy after extirpation of chromaffin tumor].

Left adrenal pheochromocytoma and mesenteric paraganglioma were diagnosed in a 52-year-old female with diabetes mellitus (fasting blood glucose 14.5 mmol/l), hypertension and myocardial asymmetric septal hypertrophy (septal/left ventricular free wall thickness 1.31). Carbohydrate metabolism and cardiac disease returned to normal after the resection of both tumors (fasting blood glucose 5.2 mmol/l, septal/left ventricular free wall thickness 1.10). This is the first patient reported in the Spanish literature in whom asymmetric septal hypertrophy has been correlated with the hypersecretion of catecholamines.

Adrenal Gland Neoplasms↗
PubMed1989

Fenfluramine and dextroamphetamine treatment of childhood hyperactivity. Clinical and biochemical findings.

Twenty boys (mean age, 9 +/- 2 years) with attention deficit disorder with hyperactivity received three weeks each of dextroamphetamine sulfate (0.5 mg/kg/d), fenfluramine hydrochloride (0.6 mg/kg/d increased to 2.0 mg/kg/d), and placebo in a double-blind, random-order, crossover design. Half the boys also met criteria for conduct disorder. Dextroamphetamine produced immediate and marked improvement in disruptive, overactive behaviors. Fenfluramine had no effect on any behavioral measure at either the low or high dosage. Both drugs decreased levels of urinary norepinephrine, 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid. Fenfluramine, however, also produced a significant decrease in plasma MHPG levels and a larger decrease in urinary norepinephrine levels. It reduced urinary epinephrine levels as well, an effect opposite to that of dextroamphetamine. These findings suggest that different mechanisms of action are involved in the ability of the two drugs to reduce levels of MHPG and vanillylmandelic acid. Fenfluramine increased plasma prolactin levels and decreased platelet serotonin levels. Despite the structural similarity of the two drugs, some common overall effects on catecholamine metabolism, and similar effects on weight, fenfluramine had none of the motor activity or therapeutic effects of dextroamphetamine.

Attention Deficit Disorder with Hyperactivity↗
PubMed1989

Comparison of in-house allergen extracts of Phleum pratense (timothy grass) pollen with the international standard and investigation of IgE specificities of a grass-pollen serum pool from West Germany and of the one recommended by the World Health Organization.

We compared our in-house reference extract (RE) and a production extract (PE) with the international reference preparation (IRP) of International Union of Immunological Societies of timothy-grass pollen, using various biochemical and immunochemical methods. Furthermore, we compared the IgE composition of our in-house grass-pollen serum pool (West Germany) with the serum pool recommended by the World Health Organization, using the RE for crossed radioimmunoelectrophoresis (CRIE). Our extracts (RE and PE) were nearly comparable with the IRP. Only by CRIE one more allergen could be detected in RE and PE than in IRP and in another extract purchased from an American company. This finding may depend on the region where the source materials were harvested and which source materials were used for the preparation of the extracts. Furthermore, by high-performance liquid chromatography in the low-molecular-weight range, two distinct peaks could be detected in the nondiafiltered IRP, which were detected in the diafiltered RE and PE as traces only. The IgE composition of our in-house grass-pollen serum pool was comparable with the serum pool recommended by the World Health Organization, as detected by CRIE using RE.

Allergens↗
PubMed1989

[Distal hemoperfusion during coronary angioplasty with prolonged balloon inflation].

We present the results of 6 coronary angioplasties associated with coronary distal hemoperfusion by an injection pump. The inflation mean time was 5 min 10 sec and the quantity of perfused blood was 43 +/- 14 ml. The procedure was successful in all cases. No biochemical alterations were detected in the perfused blood. A significant clinical and electrocardiographic improvement was observed in all but 2 cases. The cause was the occlusion of a collateral branch and a high flow pattern, respectively. Technical aspects and usefulness of this and other perfusion systems are analysed.

Aged↗
PubMed1988

MHC class II antigen-bearing dendritic cells in pulmonary tissues of the rat. Regulation of antigen presentation activity by endogenous macrophage populations.

Collagenase digestion of tissue slices from perfused, lavaged SPF rat lung released approximately 10(8) viable mononuclear cells per gram tissue, which comprised 35% T lymphocytes and up to 26% macrophages. A subset of these cells that were Ia+, surface Ig-, nonadherent, FcR- and of ultra low density (putative dendritic cells [DC]), presented protein antigen to immune T cells in vitro, and this function was inhibited by the presence of low numbers of endogenous adherent, FcR+ cells (putative macrophages). APCs were also identified in digests from tracheal epithelium, and were shown to bind antigen in immunogenic form as a result of natural (inhalation) exposure in vivo. Immunoperoxidase staining of frozen sections revealed populations of strongly Ia+ cells with prominent DC-like morphology within the alveolar septal walls and the tracheal epithelium; in both areas, they were closely associated with pleiomorphic cells that expressed macrophage surface markers. We accordingly postulate that interactions between Ia+ antigen-presenting DCs and endogenous tissue macrophages play an important role in regulating T cell activity in the respiratory tract.

Animals↗
PubMed1988

High correlations of norepinephrine, dopamine, and epinephrine and their major metabolite excretion rates.

We have previously reported high correlations between norepinephrine and its metabolite outputs in depressed patients. In this article, we expand this finding to healthy volunteers and alcoholic patients. Furthermore, we find similar high correlations between urinary outputs of dopamine, norepinephrine, and their major metabolites. The same is true, to a lesser degree, for epinephrine and metanephrine outputs. There are implications of these findings for psychobiological research on the monoamine systems.

Adult↗
PubMed1987

Thromboxane synthesis inhibition reverses group B Streptococcus-induced pulmonary hypertension.

Group B Streptococcus (GBS) sepsis in humans may cause the persistent pulmonary hypertension syndrome. Infusions of GBS in animals elevate pulmonary artery pressure (PAP) and resistance and are associated with elevated thromboxane levels. We investigated the hemodynamic effects of the specific thromboxane synthesis inhibitor, dazmegrel, in a piglet model of GBS-induced pulmonary hypertension. PAP rose from 22 +/- 6 to 42 +/- 11 (SD) mm Hg during infusion of heat-killed GBS; pulmonary vascular resistance increased from 1440 +/- 400 to 4000 +/- 1040 dyne X sec/cm5. No significant changes in cardiac output, mean arterial pressure, or left atrial pressure were noted. Treatment with 1 mg/kg of dazmegrel resulted in a rapid return of PAP and resistance to control values. No other hemodynamic effects of either bacteria or drug were observed despite continued infusion of GBS.

Animals↗
PubMed1987

[Identification of a protein related to the S-antigen in choroid plexus in quails].

Using monoclonal and polyclonal antibody immuno-fluorescence, various areas of the quail diencephalon were tested immunocytochemically for the presence of S-antigen, which is a regulatory protein of retinal photoreceptors. In adult quail and embryos (from day 13 until hatching), S-antigen immunoreactivity was demonstrated in the cytoplasm of epithelial cells in the choroid plexus of the third ventricle. Similar data have previously been obtained in quail retinal photoreceptors. No labeling could be seen in the other investigated diencephalic areas, including the hypothalamus. Although an extraocular photoregulation of the reproductive cycle has previously been reported in birds, further investigations are needed before it can be concluded that the choroid plexus of the third ventricle is involved in this or other types of regulation.

Animals↗