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Biomedical subjects

J Jackson

Publications and source records attributed to J Jackson.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

The role of transcriptional activation in the function of the Drosophila myb gene.

Vertebrate myb genes encode DNA-binding proteins that regulate transcription and have been implicated in regulation of cell proliferation, differentiation, and apoptosis. We have demonstrated that the single myb gene in Drosophila melanogaster, Dm myb, is required for the G(2)/M transition of the cell cycle and for suppression of endoreduplication. Recently, it has become apparent that the family of proteins containing Myb-related DNA-binding domains is much larger than originally believed and that the biochemical properties and functions of these proteins are diverse. We undertook studies to characterize the biochemical properties of the Drosophila Myb protein (DMyb). We now provide evidence that in addition to having homology with the vertebrate Myb proteins, the Drosophila Myb protein (DMyb) shares its biochemical properties. DMyb binds to a similar consensus sequence and activates transcription from a reporter construct regulated by vertebrate Myb proteins. We also show that DMyb proteins carrying mutations corresponding to previously isolated mutant alleles of Dm myb are less active as transcriptional activators than wild-type DMyb, indicating that a decrease in transcriptional activation ability is likely to cause the mutant phenotypes.

Animals↗
PubMedDate not supplied

Acalculous cholecystitis complicating hepatic intraarterial lipiodol: case report.

Hepatic intraarterial injection of Lipiodol has been used by various authors to enhance the diagnostic accuracy of computed tomography in hepatic tumors. The technique appears safe and seems free from serious complications when used judiciously. We report a case in which injection of hepatic intraarterial Lipiodol precipitated acalculous cholecystitis requiring urgent laparotomy.

Angiography↗
PubMedDate not supplied

An IgG autoantibody which inactivates C1-inhibitor.

Antibodies are considered to play a specific pathogenic role in certain disease states such as myasthenia gravis, Graves' disease and autoimmune haemolytic anaemia. Autoantibodies which interfere with the function of enzyme cascade systems have also been described in diseases such as acquired haemophilia (anti-factor VIII antibodies) and glomerulonephritis (C3 nephritic factor). The identification of these autoantibodies is crucial to an understanding of the aetiology of such diseases and is also of importance in revealing the inter-relationships of the immune system with other biological pathways. This is the first report of an immunoglobulin G (IgG) autoantibody reactive with C1-inhibitor (C1-Inh), a pivotal inhibitor of the inflammatory response which is known to inactivate proteins of the complement, kinin, fibrinolytic and 'contact phase' systems. This autoantibody was isolated from a patient with a novel variant of acquired angioedema and C1-Inh dysfunction. This finding highlights the involvement of the immune system in the pathogenesis of disorders characterized by the presence of dysfunctional inflammatory response proteins.

Autoantibodies↗
PubMedDate not supplied

Tubular carcinoma of the breast: a population-based study of nodal metastases at presentation and of patterns of relapse.

Tubular carcinoma of the breast (TCB) is a recognized histologic variant of infiltrating ductal carcinoma (IDC) and has been considered to have a comparatively favorable prognosis. However, previous studies have been based on small numbers of cases, some pure TCB and some mixed histology, or have not employed an appropriate comparison group. In this study 171 pure TCB cases and a comparison group of 386 cases with grade I (well differentiated) IDC were identified in a population-based database maintained by the British Columbia Cancer Agency (BCCA). The proportion of cases with axillary nodal involvement at presentation was lower in TCB cases than in the grade I IDC comparison group (12.9% and 23.9%, respectively; p < 0.05). Low-risk tumors (T1 and without vascular lymphatic or perineural invasion) were more prevalent in the TCB patients than in the grade I IDC patients (66.7% and 60.0%; p < 0.05). Low-risk TCB cases had a significantly lower rate of nodal metastases at presentation than low-risk grade I IDC cases (7.0% and 13.2%; p < 0.05). Kaplan-Meier and log-rank analyses indicated a statistically significantly lower rate of local recurrence in TCB cases than among IDC cases (p < 0.05) and a trend toward a lower rate of systemic relapse in TCB cases (p = 0.07). However, no difference in disease-specific survival was observed between TCB cases and grade I IDC comparisons. We conclude that the biologic behavior of TCB was more favorable than that of a comparison group of IDC cases. In view of the low incidence of axillary node metastases at presentation in the low-risk TCB subset (7%), axillary dissection may be omitted as part of the initial surgical management in these patients.

Adenocarcinoma↗
PubMedDate not supplied

Evaluation of a portocaval venograft and ameroid ring for the occlusion of intrahepatic portocaval shunts in dogs.

OBJECTIVE: To evaluate the use of a portocaval venograft and ameroid constrictor in the surgical management of intrahepatic portosystemic shunts (PSS). STUDY DESIGN: Prospective, clinical study. ANIMAL POPULATION: Ten client-owned dogs with intrahepatic PSS. METHODS: Portal pressure was measured after temporary suture occlusion of the intrahepatic PSS. In dogs with an increase in portal pressure greater than 8 mm Hg, a single extrahepatic portocaval shunt was created using a jugular vein. An ameroid ring was placed around the venograft and the intrahepatic PSS was attenuated. Transcolonic pertechnetate scintigraphy was performed before surgery, 5 days after surgery, and 8 to 10 weeks after surgery. Dogs with continued portosystemic shunting were evaluated further by laparotomy or portography. Clinical outcome and complications were recorded. RESULTS: Mean (+/- SD) portal pressure increased from 6 +/- 3 to 19 +/- 6 mm Hg with PSS occlusion; in all 10 dogs, the increase in portal pressure was greater than 8 mm Hg. There were no intraoperative complications, and, after creation of the portocaval shunt, the intrahepatic PSS could be completely ligated in 8 of 10 dogs. The final portal pressure was 9 +/- 4 mm Hg. Postoperative complications included coagulopathy and death (1 dog), ascites (3 dogs), and incisional discharge (3 dogs). Five of 8 dogs had continued portosystemic shunting at 8 to 10 weeks after surgery. Multiple extrahepatic PSS were demonstrated in 4 of these dogs. Clinical outcome was excellent in all 9 surviving dogs. CONCLUSIONS AND CLINICAL SIGNIFICANCE: The surgical technique resulted in a high incidence of multiple extrahepatic PSS. Short-term clinical results were promising, but long-term outcome must be evaluated further.

Animals↗
PubMedDate not supplied

Phialophora richardsiae infection in humans.

Phialophora richardsiae infection in humans is rare. The first human isolate was recovered from a patient with a phaeomycotic cyst in 1968. Since 1975 seven other cases have appeared in the world literature, and an additional case is reported here. The mean age of these nine patients was 61.4 years. Two patients had diabetes mellitus, one had diabetes mellitus and disseminated adrenocortical carcinoma, and one had a myeloproliferative disorder. The mode of acquisition was presumed to be inoculation with contaminated plant material, but a history consistent with an inoculation injury was obtained in only four patients and a retained splinter was found in the lesion of only one patient. Infection with P. richardsiae was not associated with systemic symptoms or signs. Six patients presented with a single subcutaneous cystic granulomatous lesion. One patient had chronic dacryocystitis. More extensive or invasive disease occurred in two patients, both with an ultimately fatal underlying neoplastic process. A specific etiologic diagnosis was made by culture of purulent material obtained by excisional biopsy in six patients, incision and drainage in one patient, aspiration in one, and spontaneous drainage in one. Subcutaneous nodules were cured with surgical excision. There is insufficient information concerning antifungal therapy to recommend its use.

Female↗
PubMedDate not supplied

Effects of expectancies on women's reports of moods during the menstrual cycle.

Social expectancies are assumed by many researchers to influence the reporting of menstrual and premenstrual symptoms. This study investigated the role of expectancies by attempting to manipulate college women's expectancies for a negative mood-menstrual relationship and observing the effect on self-reported daily moods. One group of women viewed a videotaped lecture designed to increase expectancies for a negative mood-menstrual relationship while a second group viewed a lecture designed to decrease such expectancies. A third group was exposed to a lecture on an unrelated topic, and a fourth, blind control group was neither exposed to a lecture nor aware that the study was concerned with the menstrual cycle. Expectancies were assessed immediately before and after presentation of the lectures. In addition, all participants monitored their moods for 40 consecutive days, after which expectancies were reassessed. Results indicated that expectancies were altered in the predicted directions by the experimental manipulations, with group differences apparent even at the 40 day follow-up. Even more importantly, daily moods during the course of the menstrual cycle were also affected by the manipulations, thus supporting the importance of expectancies as a determinant of mood.

Adolescent↗