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Biomedical subjects

R Donnellan

Publications and source records attributed to R Donnellan.

8 recordsLinked to original sources
PubMed2001

Cyclin E immunoexpression in breast ductal carcinoma: pathologic correlations and prognostic implications.

Abnormalities of the cell cycle are present in all neoplasms. Cyclin E, which regulates the G1/S phase transition of the cell cycle, plays an important role in many different cancers. To further investigate the role of cyclin E in invasive breast ductal carcinomas in South African women, representative sections from 157 mastectomy and axillary clearance specimens were stained with the cyclin E antibody. The results were compared with known clinicopathologic prognostic factors, namely lymph node metastases, size, estrogen receptor status, and histologic grade. Positive (nuclear) cyclin E immunostaining strongly correlates with negative estrogen receptor status and high grade. These correlations may account for the observation that although cyclin E staining is associated with poor prognosis in univariate analysis, no prognostic significance remains after multivariate analysis.

Aged↗
PubMed1999

Granuloma inguinale (donovanosis) presenting as a neck mass in an infant.

A case of granuloma inguinale (GI) presenting as a lateral neck mass in a 4-month-old, HIV-positive infant is described. The histological features of the mass were typical of GI, with numerous macrophages containing intracellular organisms with a "closed-safety-pin" appearance. This is a rare occurrence, and the mode of transmission of infection is discussed. An awareness of GI in infants by both clinicians and pathologists is important to prevent morbidity and allow for prompt institution of appropriate treatment.

AIDS-Related Opportunistic Infections↗
PubMed1999

Cyclin E in human cancers.

Regulators of the cell cycle such as cyclin E play an important part in neoplasia. The cyclin E protein forms a partnership with a specific protein kinase. This complex phosphorylates key substrates to initiate DNA synthesis. Cyclin-dependent kinase inhibitors (CKIs) are able to suppress the activity of cyclin E. Various substances (including proteins produced by oncogenic viruses) affect cyclin E directly or indirectly through an interaction with CKIs. These interactions are important in elucidating the mechanisms of neoplasia. They may also provide prognostic information in a wide range of common cancers. Cyclin E may even be a target for treatment of cancers in the future.

Breast Neoplasms↗
PubMed1998

Cyclin D1 and human neoplasia.

Neoplasia is characterised by abnormal regulation of the cell cycle. Cyclin D1 is a protein derived from the PRAD1, CCND1 or bcl-1 gene on chromosome 11q13, which is involved in both normal regulation of the cell cycle and neoplasia. In the G1 (resting) phase of the cell cycle, cyclin D1 together with its cyclin dependent kinase (cdk) partner, is responsible for transition to the S (DNA synthesis) phase by phosphorylating the product of the retinoblastoma gene (pRB), which then releases transcription factors important in the initiation of DNA replication. Amplification of the CCND1 gene or overexpression of the cyclin D1 protein releases a cell from its normal controls and causes transformation to a malignant phenotype. Analysis of these changes provides important diagnostic information in mantle cell (and related) lymphomas, and is of prognostic value in many cancers. Knowledge of cyclin D1's role in malignancy at the various sites, provides a basis on which future treatment directed against this molecule can proceed.

Biomarkers, Tumor↗
PubMed1997

Rate of seasonal spread of respiratory syncytial virus in a pediatric hospital.

The rate of nosocomial respiratory syncytial virus (RSV) infection was measured in a large pediatric hospital using an incidence density method. The at-risk days for nosocomial RSV were summed during a defined winter period in which there were 54 admissions with community-acquired RSV infection giving a rate of 2.9 cases per 1,000 at-risk days (95% confidence interval, 0.3-5.4 per 1,000).

Community-Acquired Infections↗
PubMedDate not supplied

Vulval myxoid liposarcoma.

A 26 year old woman presented with a 4-year history of a gradually enlarging fluctuant mass on the left labium majus. Histologic examination following excision revealed myxoid liposarcoma. Following the diagnosis, further surgery was performed to ensure complete resection. Routine excision of draining lymph nodes is not advocated. Although rare, myxoid liposarcoma should be considered in the differential diagnosis of a vulval soft tissue mass.

Adult↗
PubMedDate not supplied

Perineurioma: an unusual cause of an external auditory canal polyp.

A 33-year-old woman presented with pruritus of the right ear and on examination was found to have 1 x 1 cm polypoid lesion in the external auditory canal. This was removed and histological examination revealed a well-circumscribed spindle cell lesion arranged in fascicles and whorls. Immunohistochemistry showed the tumor to be EMA-positive but S-100-, desmin-, actin-, and cytokeratin-negative. Ultrastructural examination confirmed perineurial cell origin. There are several lesions in which perineurial cells are present, but a true perineurioma is composed exclusively of perineurial cells. It has characteristic morphological, immunohistochemical and ultrastructural features that help separate it from other nerve and neuroectodermal lesions.

Adult↗