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Biomedical subjects

J Oliver

Publications and source records attributed to J Oliver.

At least 163 records · Page 9Linked to original sources
PubMed1987

Murine autoimmune oophoritis, epididymoorchitis, and gastritis induced by day 3 thymectomy. Autoantibodies.

In adult mice thymectomized at age 3 days (D3TX), increased incidences and/or levels of organ-specific antibodies to oocytes and/or zona pellucida, to testicular cell-sperm-differentiation antigens (TSDA), and to gastric parietal cells were detected, and these correlated significantly with oophoritis, orchitis (not epididymovasitis), and gastritis, respectively. The autoantibodies occurred in mice with the corresponding endogenous antigens. Thus, anti-oocyte/zona antibodies were detected in female, anti-TSDA antibodies in male, and anti-parietal cell antibodies in both sexes. Anti-oocyte/zona antibodies were first detected at age 5-6 weeks and were absent by 25 weeks. Serum antizona antibodies, but not anti-oocyte antibodies, inhibited mouse fertilization in vitro. In contrast, antibodies to sperm acrosome and antibodies to sperm surface did not correlate with testicular or epididymal disease. Moreover, both male and female mice had increased levels of anti-sperm surface antibodies, indicating that the sperm antigens detected may not be organ-specific. In addition, sera from 5-10% of D3TX mice reacted with a wide spectrum of epididymal and testicular antigens with defined cellular locations but of yet unknown specificity. Although the incidence of antibodies to cytoskeletal antigens was not significantly elevated after D3TX, anti-nuclear antibodies were more frequently detected in (SWR/J X A/J) F1 (SWRAF1) and (C57 BL/6J X A/J) F1 (B6AF1) mice after D3TX.

Animals↗
PubMed1986

Origin of the afferent connections to the parolfactory lobe in quail shown by retrograde labelling with a fluorescent neuron tracer.

Unilateral injection of Fast Blue retrograde fluorescent neuron tracer into the parolfactory lobe (POL) in the quail showed multiple innervation of this structure. Neurons projecting into the POL were located in three areas: the telencephalon, where they were scattered in the paleostriatum, the archistriatum and ventral hyperstriatum, and among the fibers of different tracts including the anterior commissure, the occipito-mesencephalic tract and the fasciculus prosencephali lateralis; the diencephalon, where fluorescent neurons with large multipolar perikarya were found in the dorsal thalamic wall; the midbrain, where large perikarya were located in the ventralis area of Tsai, the locus coeruleus, the nucleus subcoeruleus, around the medial longitudinal fasciculus, in the substantia grisea centralis, the formatio reticularis mesencephali and among the fibers of the brachium conjunctivum. In most cases, axons innervating the POL ran parallel to the fibers of the medial forebrain bundle and contralateral to the perikarya from which they originated. This study also showed that the anterior and posterior parts of the POL received fibres from different sources.

Animals↗
PubMed1986

Treatment of childhood hyperactivity with desipramine: plasma drug concentration, cardiovascular effects, plasma and urinary catecholamine levels, and clinical response.

Twenty-nine boys with attention deficit disorder/hyperactivity were randomly assigned to receive desipramine (DMI; n = 17) or placebo (n = 12) for 14 days in a noncrossover, double-blind study. There was immediate behavioral improvement with DMI at day 3 that was sustained for 2 weeks; behavioral improvement did not correlate with plasma concentrations of DMI, hydroxy-DMI, or their sum at either days 3 or 14. There were no untoward side effects; there was a drug-induced increase in pulse and diastolic blood pressure. During drug therapy, the urinary excretion of norepinephrine, vanillymandelic acid, and 3-methoxy-4-hydroxyphenylglycol (MHPG) was decreased at both days 3 and 14. The plasma MHPG level was decreased at days 3 and 14 and (standing) plasma NE levels increased at day 14. The decreases in both urinary and plasma MHPG levels showed significant correlations with behavioral improvement during the second week. These data corroborate previous findings on sympathomimetic effects of tricyclic antidepressants in children and support a noradrenergic mechanism in the mediation of drug effects on attention deficit disorder/hyperactivity.

Administration, Oral↗
PubMed1986

Biologic activity of purified cotton bract extracts in man and guinea pig.

Purified aqueous extracts of cotton bract induce acute airway constriction in healthy volunteers never before exposed to cotton bract. The response is similar to that of textile workers who inhale cotton dust. Approximately 60% of volunteers respond to bract extract with significant decreases in lung function, and these volunteers show an increased number of lymphocytes present in their lungs. Following inhalation of bract, the percent of polymorphonuclear leukocytes increases. Macrophages obtained by bronchoalveolar lavage from volunteers pre-challenged with bract extract release increased amounts of chemotactic factor and superoxide anion. Efforts to detect release of histamine and leukotrienes in volunteers following challenge with bract show no increase in urinary histamine and no significant release of leukotrienes in lung lavage fluid. Purified extracts exhibit chemotactic activity in vitro. They also contract guinea pig ileal longitudinal muscle in vitro. This preparation contains mast cells but no basophils, and the H-1 blocker, mepyramine blocks the contraction. Purified bract extracts contain no histamine or endotoxin but other contractors of smooth muscle may be present. The purified extract exhibits spectral, fluorescent, and radioimmune assay properties similar to a leukotriene B-like component. Cotton bract appears to have direct as well as cell-mediated activities.

Adolescent↗
PubMed1985

Respiratory functional changes on intratracheal challenge of sensitized rats.

Inbred PVG/c rats were sensitized to DNP19-ovalbumin by intraperitoneal injection. Sensitized rats when challenged with antigen developed characteristic brief interruptions of expiratory flow ('expiratory notching'). The functional residual capacity fell in rats challenged with antigen or saline but the fall was greater in those sensitized rats challenged with antigen. No greater alterations in respiratory rate, minute volume, airways resistance or dynamic compliance occurred on antigen as compared with saline challenge of sensitized rats, suggesting that the expression of immediate respiratory hypersensitivity in the rat is different from the asthmatic response in humans. The expiratory notching was reduced if an additional airways resistance was added in series to the tracheostomy tube. This may be explained as a result of reduction in the dynamic compression which normally produced the expiratory notching.

Airway Resistance↗
PubMed1985

Comparison of the effects of thymosin and other thymic factors on modulation of interleukin-2 production.

Thymosin fraction 5 (TF5) enhances interleukin-2 (IL-2) production by human peripheral blood mononuclear leukocytes (PBL) when cocultured in the presence of phytohemagglutinin (PHA). This important biological activity of TF5 is not due to the presence of two previously well-characterized component peptides, thymosin alpha 1 and thymosin beta 4, but rather to a new, still to be identified component of TF5. Comparison of TF5 with other well-defined thymic preparations and peptides indicates that this biological activity is unique to TF5 and a closely related extract prepared from porcine thymus tissue. Using a standard human PBL cell population obtained by leukopheresis and cryopreservation, it should now be possible to establish a reproducible bioassay for the isolation and characterization of one or more components of TF5 with the property of enhancing PHA-induced IL-2 production by human PBL.

Animals↗
PubMed1984

Determination of urinary 4-hydroxy-3-methoxyphenylethylene glycol in man by high performance liquid chromatography with electrochemical detection.

A reverse phase high performance liquid chromatographic method for determining levels of 4-hydroxy-3- methoxyphenylethylene glycol (MHPG) in human urine that is virtually free of all interfering peaks has been developed. After addition of a homologous internal standard, enzymatic hydrolysis is performed. Samples are then placed onto columns containing AG1-X8, and the MHPG is collected in a phosphate buffer wash of the column. After ethyl acetate extraction and evaporation of the organic solvent, the dry residue is redissolved in mobile phase, and injected onto a reverse phase column. Results obtained with this assay were almost identical (101+/-5.6%, mean+/-SD, n=6) with those obtained using a gas chromatography - mass spectrometry (GCMS) assay.

Chromatography, High Pressure Liquid↗
PubMed1984

Coronary artery disease in blacks: risk factors.

The current literature indicates that of the major risk factors for coronary artery disease (CAD), United States blacks and whites have similar rates for cigarette smoking and cholesterol levels. The prevalence of diabetes mellitus is higher in black females than white females. Both black males and females have higher prevalence rates for hypertension. These differences in risk factors between blacks and whites in spite of similar degrees of CAD suggest that the relative importance of specific risk factors might differ between the two racial groups. Research is needed to determine if there are protective factors in blacks (e.g., high-density lipoprotein cholesterol) and/or previously unrecognized risk factors (e.g., diuretic-induced lipid abnormalities) that may be playing a major role in the epidemiology of CAD in the black population.

Adult↗
PubMed1984

Cardiac size and function in Paget's disease of bone.

We performed non-invasive assessment of cardiac size and function by clinical criteria, standard electrocardiography, chest X-ray, systolic time intervals and echo-cardiography in 27 patients with Paget's disease of bone and in 20 control subjects. The patients were divided into two groups on the basis of the degree of skeletal involvement (less than 15% in Group I and greater than 15% in Group II). No differences in heart size parameters of left ventricular performance were noted between Group I and controls. Cardiomegaly, increased left ventricular diastolic dimension and increased left ventricular mass indicative of ventricular hypertrophy were found in Group II compared to control subjects. In addition, patients with more extensive skeletal involvement had signs of depressed myocardial contractility, increased left ventricular volumes in diastole and systole and enlarged stroke volume, with no differences in echographic cardiac output compared to Group I and controls. The findings show an above normal incidence of cardiac enlargement and disturbed left ventricular performance in patients with Paget's disease and osseous lesions in greater than 15% of skeleton. The clinical implications of the altered cardiac function in patients with Paget's disease are briefly discussed.

Aged↗
PubMed1984

Prevention of thromboembolism using aspirin after mitral valve replacement with porcine bioprosthesis.

The thromboembolic rate of 768 patients who were treated only with aspirin after mitral valve replacement or mitral plus aortic valve replacement with porcine bioprostheses was evaluated. We analyzed the thromboembolic rate for the whole series and for subgroups of patients categorized by atrial fibrillation, giant left atrium, left atrial thrombosis, and dosage of aspirin (1 gm daily or 0.5 gm every 48 hours). The total embolic rate was 1.4% (11/768). No patient in sinus rhythm had an embolic event. The embolic rate for patients in atrial fibrillation was 1.9% (11/583). There were no embolic events in 31 patients with a giant atrium. An embolic event occurred in 1 of 42 patients with atrial thrombosis (2.4%). Patients treated with 1 gm of aspirin daily had a 3% embolic rate (9/295) while the incidence was 0.4% (2/473) in those treated with 0.5 gm every 48 hours (p less than 0.01). Administration of aspirin after mitral valve replacement with a bioprosthesis is a very effective treatment for prevention of thromboembolism. In our experience, this treatment provides protection equal to or better than that offered by oral anticoagulants for patients in atrial fibrillation as well as for patients with a giant atrium or atrial thrombosis at operation. The dosage and timing of aspirin administration may markedly affect the result of this type of treatment. Oral anticoagulation with coumarin derivatives may not be appropriate after mitral valve replacement with a bioprosthesis, and platelet antiaggregates should be used for this purpose in the future.

Adolescent↗
PubMed1984

Do individuals with Down's syndrome possess right hemisphere language dominance?

A dichotic digits task with selective listening and attention-switching instructions, was administered to 10 mentally retarded individuals with Down's Syndrome between the ages of 10 and 37 years. Attention was focused on one ear for 20 trials before switching attention to the opposite ear after a 5-minute interval. A majority displayed a right ear-left hemisphere advantage for correct responses, although this advantage failed to reach significance. Comparison of left and right ear intrusion errors when each ear was attended first showed significantly more intrusions from the unattended right ear. No priming effects were found. The results do not support the hemispheric reversed specialization hypothesis. Rather, it is suggested that while Down's Syndrome individuals do possess an inherent left hemisphere advantage for language, such individuals may suffer from a left hemisphere information processing disorder that can produce functional reversals in dichotic listening.

Adolescent↗
PubMed1984

Thymosin increases production of T-cell growth factor by normal human peripheral blood lymphocytes.

The in vitro incubation of phytohemagglutinin-stimulated peripheral blood lymphocytes with thymosin results in a marked and reproducible increase in production of T-cell growth factor, which is dose dependent and most pronounced in the first 24 hr of culture. Incubation of lymphocytes with thymosin alone failed to induce any production of T-cell growth factor. The biological activity of thymosin fraction 5 cannot be attributed to the activity of thymosin alpha 1, one of the well-characterized peptide components of fraction 5. These data provide the basis for (i) a potential mechanism for the in vivo immunorestorative effects of thymosin in primary and secondary immunodeficiencies and (ii) identification of an additional, but as yet undefined, immunoregulatory component of thymosin fraction 5.

Dose-Response Relationship, Drug↗
PubMed1984

Suppressor cell responses in patients with rheumatoid arthritis: the effect of thymosin.

Peripheral blood lymphocytes (PBL) from patients with rheumatoid arthritis (RA) and age and sex-matched normal controls were compared in a Concanavalin A (Con A)-induced suppressor cell assay. Suppression induced by pre-incubation with Con A was significantly greater in PBL from RA patients than in PBL from normal controls. Preincubation with thymosin fraction 5, in the absence of Con A, also induced greater suppressor cell activity in PBL from normal controls. Preincubation with Con A and thymosin, simultaneously, induced suppression similar to that seen with Con A alone. These results suggest the presence of an immunoregulatory defect in RA, characterized by an excess of both Con A and thymosin-inducible suppressor cells, that may play a role in disease pathogenesis. The implications of these observations for immunotherapy of rheumatoid arthritis with thymosin are discussed.

Adult↗
PubMed1983

A comparison between the ease of haemoglobin oxidation and modification by sulphide.

The haemoglobin purified from a wide range of species undergoes facile sulphaemoglobin formation as well as oxidation. Oxidation by either anions such as azide or organic electron transfer reagents shows similar facility. Facile oxidation of a particular haemoglobin is associated with protection against sulphaemoglobin formation. Oxidation and sulphaemoglobin formation in some instances occur via competing electron transfer reactions.

Animals↗