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Biomedical subjects

J Stewart

Publications and source records attributed to J Stewart.

At least 469 records · Page 26Linked to original sources
PubMed1984

An immunohistological study of secondary Sjögren's syndrome.

The labial biopsies from 13 patients with secondary Sjögren's syndrome (SS) and four disease controls were examined with a panel of monoclonal antibodies to human leucocyte antigens. Large numbers of T cells were found in most of the biopsies. In seven SS patients the T helper/inducer subset was found to be predominant. Antibody to HLA class I antigens consistently stained leucocytes, but other cell types stained more variably. Although the staining with antibody to HLA class II antigen was often weak, approximately as many cells stained with this antibody as with an antileucocyte antibody, implying that the T cells were activated. Anti-IgD revealed membrane staining of a corona of IgD-positive cells in structures resembling germinal centres. Isolated cells throughout the sections also showed strong cytoplasmic staining with anti-IgD. These results suggest a role for T-cell-dependent local antibody synthesis in the pathogenesis of the disease.

Adult↗
PubMed1984

Hemorrhage and the products of fibrinogen digestion after intracoronary administration of streptokinase.

Hemorrhage was prospectively identified in 26 of 116 consecutive patients (23%) who were receiving intracoronary streptokinase for occlusive coronary thrombi producing infarction. Bleeding was not influenced by the dose of streptokinase or the method of cardiac catheterization. Before treatment, prothrombin time and partial thromboplastin time were normal in both bleeders and nonbleeders. Fibrinogen levels measured by bioassay after streptokinase (mean +/- SEM) were 62 +/- 29 mg/dl in patients with major bleeding, 111 +/- 26 mg/dl in patients with minor bleeding, and 109 +/- 13 mg/dl in nonbleeders (p = NS). The regression slope b calculated from poststreptokinase fibrinogen time-concentration data in 71 patients was 4.7 mg/dl/hr. However, mean fibrinogen concentrations calculated at sequential 5 hr intervals revealed no net regeneration for the first 20 hr after thrombolysis. The apparent fibrinogen regeneration rate was less than normal (31 mg/kg/day) for more than 10 hr but subsequently increased to 94 +/- 10 mg/kg/day by the second day. The initial apparent latency of fibrinogen regeneration paralleled the sharp rise in fibrinogen degradation products, which began to decline after 20 hr of treatment but remained elevated well into the second day. Because of their anticoagulant effects, these products may interfere with the fibrinogen assay, causing spuriously low results. Thus, whether the early delay in fibrinogen regeneration is real or simply a reflection of the effects of fibrinogen degradation products on the bioassay, it signals the time for caution in initiating systemic heparin therapy.

Blood Coagulation Factors↗
PubMed1984

Defining the boundaries of atypical depression.

Psychopharacologist have had a longstanding interest in identifying a depressive subtype which selectively benefits from monoamine oxidase inhibitors (MAOIs). A superior rate of improvement with MAOI treatment might help delineate a depressive subgroup with pathophysiology different from other depressive syndromes. Research is described which indicates that patients with reactivity of mood, as well as two of four associated features (hypersomnia, overeating, lethargy, and rejection sensitivity), may have a preferential response to phenelzine as compared with imipramine or placebo. Preliminary data are presented to suggest that patients with reactive mood and only one associated feature may have a preferential response rate to phenelzine compared to imipramine and placebo. Data on patients with reactive mood but no associated features are insufficient at this point to draw any conclusions.

Clinical Trials as Topic↗
PubMed1983

Simultaneous outbreaks of Guillain-Barré syndrome and Bell's palsy in Hawaii in 1981.

Simultaneous outbreaks of Guillain-Barré syndrome (GBS) and Bell's palsy occurred among residents of Hawaii during the three-month period June through August 1981. The outbreak of GBS (six cases) involved children, while the outbreak of Bell's palsy (22 cases) involved primarily adults. Four of the six patients with GBS had serological evidence of recent infection with cytomegalovirus (CMV) v none of 24 control subjects; no such association with CMV infection could be demonstrated for patients with Bell's palsy. The patients with GBS and Bell's palsy lived in widely scattered areas within the population centers of Hawaii, and no common exposures to specific places or events were identified. Testing for antibodies to respiratory pathogens suggested that a variety of antecedent viral infections, in addition to CMV infection, may have been associated with this unusual simultaneous cluster of illnesses.

Adult↗
PubMed1983

Retinoblastoma mutation rate in New Zealand and support for the two-hit model.

Age-specific incidence rates for 96 New Zealand patients with sporadic retinoblastoma peaked earlier for bilateral patients than for unilateral patients. The cumulative log survival until diagnosis for bilateral and unilateral patients followed linear and quadratic curves respectively, and supported the two-hit hypothesis for retinoblastoma. The germ cell mutation rate for retinoblastoma, assuming a single major gene, was calculated to be in the order of 9.3 X 10(-6) to 10.9 X 10(-6) for the New Zealand population.

Age Factors↗
PubMed1983

Drug reinstatement of heroin-reinforced responding in the rat.

Non-contingent, 'priming' IV drug injections led to reinstatement of heroin-reinforced responding after a period of extinction. Rats implanted with IV catheters were trained to self-administer heroin (100 micrograms/kg/infusion diacetylmorphine HCl) and were given test sessions consisting of a period of self-administration followed by extinction conditions. 'Priming' infusions of heroin and other drugs were presented during extinction and lever pressing following the injection was observed. Priming injections of 50, 100 and 200 micrograms/kg heroin effectively restored responding after a period of extinction. Morphine and, to a lesser extent, amphetamine and apomorphine also reinstated heroin-reinforced responding whereas cocaine and clonidine did not. These results may help our understanding of 'relapse of drug-taking' behavior.

Animals↗
PubMed1983

Post-operative serum sialyltransferase levels and prognosis in breast cancer.

Serum sialyltransferase (SST) activity was measured 10 days after mastectomy in 153 patients with operable breast cancer. Enzyme activity declined with time in storage (1-42 months). After correction for loss of activity in storage, patients with SST activity below the median value had a longer disease-free interval (DFI) than those with SST activity above the median, and this difference remained when patients were stratified by axillary nodal status, tumor size, and tumor grade. Survival was longer in patients with low SST activity. Post-operative elevation of SST indicates a poor prognosis in patients with operable breast cancer.

Breast Neoplasms↗
PubMed1983

Conditioned and unconditioned drug effects in relapse to opiate and stimulant drug self-adminstration.

Humans and laboratory animals given access to opiate and stimulant drugs frequently become compulsive users of these drugs, and often, in spite of prolonged periods of abstinence, persist in drug-seeking behavior and relapse to drug-taking. Evidence suggests that such drugs act on positive appetitive systems of the brain to maintain drug-taking and that, in the absence of drugs, stimuli previously associated with the drug state might acquire the ability to arouse motivational states similar to those activated by the drugs themselves. In rats previously trained to self-administer cocaine or heroin intravenously, noncontingent 'priming' intravenous infusions of cocaine or heroin lead to reinstatement of drug-taking behavior. Priming infusions of pharmacologically related drugs and drugs with similar stimulus properties also reinstate responding. Application of morphine to the cell body region of dopaminergic neurons of the ventral tegmental area (VTA), a site known to support morphine self-administration, reinstates both heroin and cocaine self-administration behavior. Reinstatement is blocked by pretreatment with naltrexone. Morphine applied to several other brain areas rich in opiate receptors does not reinstate the behavior. Application of morphine to the VTA, a site known to support conditioned place preferences as well as self-administration, causes increased locomotion that is naloxone reversible. This locomotor activity shows sensitization upon repeated administration, an effect that is specific to the environment in which morphine is administered. Conditioned increases in activity are observed in the same environment. Neither conditioning nor sensitization develops when animals are pretreated with pimozide.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Macrophage 'receptors' for bacterial cell-wall sugars and immune response genes: possible determinants of susceptibility to infection.

Recognition of bacteria, antigen presentation and regulation of the immune response by the class II antigens of the major histocompatibility complex (MHC) are among the many factors that influence a host's response to microbial infection. 'Lectin-like' receptors on the macrophage membrane recognize a variety of bacteria by interaction with their cell-wall sugars. These receptors are susceptible to environmental factors and appear to be associated with the I-A subregion of the mouse MHC. Possible effects of this recognition system on the pathogenesis of microbial infection and reactive arthritides are considered.

Animals↗
PubMed1983

Case report of carpal tunnel syndrome associated with tranylcypromine.

A man who developed carpal tunnel syndrome while taking tranylcypromine was treated with 300 mg/day of pyridoxine, which resulted in significant improvement. The authors discuss the two major mechanisms by which monoamine oxidase inhibitors can inactivate pyridoxine.

Carpal Tunnel Syndrome↗
PubMed1983

Acute hepatitis a in West Scotland in 1981. A change in pattern.

In 1981, 151 cases of laboratory confirmed Hepatitis A infection were diagnosed in West Scotland, an increase of more than three-fold over both 1979 and 1980. The majority (54%) were in children under 15 years of age, case numbers then declining with age, apart from a rise in numbers in the 21-30 age group. Almost all children infected were Scottish children. Significant numbers were associated with contact with a known case (25%) or travel abroad (16%). Few cases were diagnosed in the first five months of the year. This upsurge in laboratory-diagnosed cases was associated with an increase in notifications of viral hepatitis to the Registrar General for Scotland for the first time in 10 years.

Acute Disease↗