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Biomedical subjects

J Coll

Publications and source records attributed to J Coll.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Ajugatansins, neo-clerodane diterpenes from Ajuga reptans.

New neo-clerodane diterpenes have been isolated from Ajuga reptans, and named ajugatansins, along with the previously reported ajugavensin A and ajugareptansone A. The structures of all the compounds were elucidated by spectroscopic means and comparison with closely related compounds reported in the literature. The new 6 alpha,19-diacetoxy-4 alpha,18-epoxy-1 beta-hydroxy-3 beta-(2-methyl-butanoyloxy)-neo-clerod-13-en-15,16-olide (ajugatansin A1) and 6 alpha,19-diacetoxy-4 alpha,18-epoxy-3 beta-hydroxy-12S-(2-methylbutanoyloxy)-neo-clerod-13-en-15,16-olide (ajugatansin B1) are structurally related to ajugarin I and (11S,13R,16S)-6 alpha, 19-diacetoxy-4 alpha,18:11,16:15,16-triepoxy-3 beta-(2-methylbutanoyloxy)-1 beta-[(E)-2-methyl-2-butenoyloxy]-neo-clerodan-2 beta-ol (ajugatansin D1) to dihydroclerodin.

Diterpenes↗
PubMedDate not supplied

Tuberculous pericarditis as the first manifestation of AIDS.

Although it is known that extrapulmonary tuberculosis in patients with AIDS has a broad spectrum of clinical manifestations, pericardial involvement has rarely been described. We report a case of this condition as the first manifestation of AIDS with good response to antituberculous therapy. Although unusual, the diagnosis of tuberculous pericarditis in symptomatic HIV-infected patients should be aggressively pursued because of the beneficial clinical response to treatment.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Status of vestibular function after prolonged bedrest.

6 young, healthy, male volunteers were submitted to one week of head down (-4 degrees) bedrest. This position simulates the cerebral hemodynamic conditions in weightlessness. Measurements of vestibular equilibrium and of oculomotor system function were made before and after the prolonged bedrest. Analysis of the results indicates that vestibular responses, as measured by the maximal speed of the slow phase of the provoked nystagmus (caloric and sinusoidal rotatory stimulations), are decreased after prolonged bedrest. This statistically significant diminution requires confirmation with a greater number of cases. The reflex conflicting or interacting with the cervico-ocular and optokinetic reflexes on the one hand and the foveal vision on the other, is one of several possible explanations for the observed changes.

Adult↗
PubMedDate not supplied

Radiographic findings in pulmonary tuberculosis: the influence of human immunodeficiency virus infection.

The chest radiographs and medical records of 166 patients diagnosed as having clinically active pulmonary tuberculosis were reviewed. Forty-nine patients (group I) were seropositives to human immunodeficiency virus (HIV), and 117 patients (group II) did not have known risk factors for HIV infection. Roentgenographic abnormalities were analysed in the two groups, according to nine different radiographic patterns previously defined. The seropositive group had a significantly higher proportion of hilar and/or mediastinal adenopathy (P less than 0.001), infiltrates confined to the lower lung fields (P less than 0.05), and miliary tuberculosis (P less than 0.005). Otherwise, single cavitation and destructive pattern were more frequent in the group II. These data suggest that patients with pulmonary tuberculosis and HIV infection are much more likely to have atypical radiographic findings.

Adult↗
PubMedDate not supplied

A putative second cell-derived oncogene of the avian leukaemia retrovirus E26.

The acute avian leukaemia retroviruses AMV and E26 both induce myeloblastosis in vivo and transform myeloblasts in vitro. Both viruses contain the oncogene v-myb first described for AMV. Unlike AMV, E26 has the additional capacity to induce erythroblastosis in vivo and to transform erythroblasts. Previous analyses indicated that the genome of E26 also contained nucleotide sequences distinct from v-myb and unrelated to viral replicative genes. Using a molecularly cloned E26 provirus, we have now identified a novel nucleotide sequence designated v-ets (for E-twenty-six specific) of approximately 1.5 kilobase pairs (kbp) located next to v-myb. v-ets possesses all the structural characteristics of a putative new oncogene: it has a conserved cellular counterpart c-ets which is transcribed in some normal chicken cells as a major 7.5-kb polyadenylated RNA. Although our results now await elucidation of their biological significance, we propose that v-ets could be a new oncogene accounting for the additional transforming properties of E26, or potentiating the transforming properties of the v-myb oncogene.

Animals↗
PubMedDate not supplied

Induction of proliferation or transformation of neuroretina cells by the mil and myc viral oncogenes.

The genome of the avian retrovirus MH2 contains, in addition to the v-myc oncogene shared with three other avian retroviruses (MC29, CMII and OK-10), a second cell-derived oncogene, v-mil (refs 1-3). Like the three other viruses, which contain only v-myc, MH2 induces mainly liver and kidney carcinomas in fowl and transforms fibroblasts and macrophages in vitro. However, MH2 and MC29 differ in their biological properties when assayed on cultures of chicken embryo neuroretina (NR) cells. Indeed, NR cells, which normally do not multiply in vitro, are induced to proliferate and become transformed upon infection with MH2, whereas infection with MC29 has no apparent effect on these cells. To analyse the functions of the two oncogenes of MH2, we isolated spontaneous and in vitro-constructed mutants of this virus and investigated their effects on NR cell multiplication and transformation. We report here that expression of v-mil is sufficient to induce NR cell proliferation, although it does not result in cell transformation. In addition, viruses expressing only the v-myc oncogene fail to induce any detectable change in NR cells. However, cooperation of the two oncogenes is required to achieve transformation of NR cells by MH2.

Animals↗