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Biomedical subjects

J Mayo

Publications and source records attributed to J Mayo.

101 records · Page 6Linked to original sources
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Growth and metastatic behavior of human tumor cells implanted into nude and beige nude mice.

The growth and metastatic behavior of several human tumor lines grown in adult nude mice, nude mice pretreated with antiserum against asialo GM1 glycoprotein, and beige nude mice were studied. The cell lines were all injected s.c. and i.v. A human colon carcinoma line was also injected into the spleen, and two human renal carcinoma lines were injected into renal subcapsule. All the tumor lines grew as fast or faster in adult nude mice compared with beige nude mice. There were no discernible differences in the production of experimental lung metastasis among the three groups of mice, but human colorectal carcinoma cells and human renal carcinoma cells produced more metastases in nude mice than in beige nude mice after intrasplenic or renal subcapsule injection, respectively. In vitro cytotoxicity assays confirmed that adult nude mice had high levels of natural killer (NK) cell activity whereas nude mice pretreated with anti-asialo GM1 serum and beige nude mice did not. The in vitro NK cell activity of nude mice was demonstrable against mouse lymphoma cells but not against human leukemia cells which were sensitive to lysis by human NK cells. These results suggest that the implantation of human tumor cells into beige nude mice, which are deficient in NK cell activity does not provide an advantageous model for the study of growth and metastasis of human neoplasms.

Animals↗
PubMedDate not supplied

Increased activity of tyrosine hydroxylase in the cerebellum of the X-irradiated dystonic rat.

The exposure of the cephalic end of rats to repeated doses of X-irradiation (150 rad) immediately after birth induces a long-term increase in the noradrenaline (NA) content of cerebellum (CE) (+ 37.8%), and a decrease in cerebellar weight (65.2% of controls), which results in an increased NA concentration (+ 109%). This increase in the neurotransmitter level is accompanied by a dystonic syndrome and histological abnormalities: Purkinje cells (the target cells for NA afferents to CE) fail to arrange in a characteristic monolayer, and their primary dendritic tree appears randomly oriented. The injection of reserpine 0.9 and 1.2 mg/kg ip to adult rats for 18 h depletes cerebellar NA content in both controls (15.7 +/- 4 ng/CE and 2.8 +/- 1.5 ng/CE, respectively) and X-irradiated rats (17.1 +/- 1 ng/CE and 8.3 +/- 2 ng/CE, respectively). The activity of tyrosine hydroxylase (TH) in CE of adult rats, measured by an in vitro assay, is significantly increased in neonatally X-irradiated animals when compared to age-matched controls (16.4 +/- 1.4 vs 6.32 +/- 0.6 nmol CO2/h/mg prot., p less than 0.01). As observed for NA levels, a net increase in TH activity induced by the ionizing radiation is also measured: 308.9 +/- 23.8 vs 408.2 +/- 21.5 nmol CO2/h/CE, p less than 0.01 (controls and X-treated, respectively). These results suggest that X-irradiation at birth may induce an abnormal sprouting of noradrenergic afferents to CE. The possibility that these changes represent a response of the NA system to the dystonic syndrome is discussed.

Afferent Pathways↗
PubMedDate not supplied

The clinical spectrum of osteoarticular tuberculosis in non-human immunodeficiency virus patients in a defined area of northwestern Spain (1988-1997).

OBJECTIVE: To examine the frequency and clinical manifestations of osteoarticular tuberculosis in non-human immunodeficiency virus (HIV) patients during the past 10 years in a northwestern area of Spain. METHODS: The charts of all patients older than 14 years of age, not HIV-infected, and diagnosed as having osteoarticular tuberculosis at the Xeral-Calde Hospital from 1988 through 1997 were reviewed. All patients were residents of the region of Lugo. The diagnosis of osteoarticular tuberculosis was made on the basis of a positive culture for Mycobacterium tuberculosis from synovial fluid, joint tissue or paravertebral abscess or by histological findings of caseating granulomas in biopsied tissue. RESULTS: Thirty-two HIV-negative patients (20 men and 12 women) were diagnosed with osteoarticular tuberculosis. The average annual incidence rate of osteoarticular tuberculosis in the combined (male and female) non-HIV population > or = 15 years of age was 15.68/million (95% CI: 10.25; 21.11); males 20.02/million (95% CI: 11.25; 28.79); females 11.52/million (95% CI: 5.00; 18.03). The age at the time of diagnosis was 60.8 +/- 17.5 years. Peripheral monoarthritis was observed in 16 of the 32 cases. The knee was the most frequent site of peripheral tuberculous arthritis (31%), but involvement of the non-weight-bearing joints (50%) was also common. Spondylitis involving the lower thoracic and upper lumbar vertebrae (31%) and unilateral sacroiliitis (19%) were less commonly observed. In general, patients with osteoarticular tuberculosis had a long duration of symptoms of the disease prior to the diagnosis (median: 5.5 months). The tuberculin skin test was negative in 3 cases. Chest radiograph was abnormal in only 6 of 32 patients (19%). The ESR (mean +/- SD) at the time of diagnosis was 55.7 +/- 29.0 mm/hr. Computed tomography was very useful in detecting early involvement of the sacroiliac joints and in defining the extent of the abscesses and the severity of the involvement in patients with spondylitis. All patients received chemotherapy for tuberculosis. None of them suffered relapses of tuberculosis. CONCLUSION: Tuberculosis is a major source of osteoarticular complications in northwestern Spain. The prevailing low level of clinical suspicion may explain the long delay to the diagnosis in most patients. A greater awareness of the possibility of this severe complication, especially in the elderly people or in high-risk populations, would be advisable.

Adolescent↗