Search PubMed⌕ Search

Biomedical subjects

P Smith

Publications and source records attributed to P Smith.

At least 217 records · Page 12Linked to original sources
PubMed1999

Cyclin-dependent kinase inhibitor p27Kip1 expression and interaction with other cell cycle-associated proteins in mammary carcinoma.

p27, cyclin D1, and retinoblastoma (Rb) protein have been demonstrated using immunohistochemistry in 189 cases of primary breast carcinoma with long-term follow-up. There was a statistically significant association between the expression of p27 and both cyclin D1 and the retinoblastoma gene product (pRb), corresponding to their close interactions in regulating the G1/S transition in the cell cycle. Low levels of p27 were seen in high-grade, rapidly proliferating, oestrogen receptor-negative tumours. In univariate analysis, low p27 expression was associated with a reduced relapse-free and overall survival. In multivariate analysis, p27 was not an independent predictor of survival when either histological grade or proliferative activity (S-phase fraction) was included in the model. When the combined expression of p27 and cyclin D1 was related to survival, patients with high levels of p27, regardless of their cyclin D1 status, did well, whilst those with low p27 had a poor outcome. The only exception, in the latter group, was patients with tumours expressing high levels of cyclin D1, who did as well as the high p27 group. We have shown that in clinical material p27 expression is associated with proliferative activity and while univariate analysis shows it to be a significant indicator of prognosis, this significance is lost in multivariate analysis when traditional prognostic factors are included in the model. The interest in p27 expression in mammary carcinoma lies in its behaviour when examined in combination with other G1 cell cycle regulators.

Biomarkers, Tumor↗
PubMed1999

Occult lifelong persistence of infectious hepadnavirus and residual liver inflammation in woodchucks convalescent from acute viral hepatitis.

Traces of hepatitis B virus (HBV) genome can persist for years following recovery from hepatitis B. To determine overall duration, molecular characteristics, and pathological implications of this serologically undetectable form of hepadnaviral carriage, we have analyzed the expression of transcriptionally active virus genomes, their infectivity, and examined liver alterations during the natural lifespan of woodchucks convalescent from acute infection with HBV- related woodchuck hepatitis virus (WHV). In this study, we document lifelong persistence of scanty amounts of replicating virus both in the liver and lymphatic system after spontaneous resolution of an episode of experimental hepadnaviral hepatitis. Antibodies to virus nucleocapsid (core) were found to be the most reliable immunovirological marker coexisting with occult infection. In the majority of convalescent woodchucks, serial liver biopsies showed protracted minimal to mild necroinflammation with periods of normal morphology; however, hepatocellular carcinoma (HCC) ultimately developed in 2 of 9 animals studied. Inocula derived from lymphoid cells of convalescent animals induced classical acute hepatitis in virus-naive woodchucks that progressed to chronic hepatitis and HCC in 1 of the animals, demonstrating infectivity and pathogenic competence of the carried virus. Our results reveal that low levels of infectious WHV and residual hepatic inflammation usually continue for life after resolution of hepatitis and that this recovery does not avert HCC development. They also demonstrate that, in addition to the liver, the lymphatic system is the site of the occult lifelong maintenance of replicating hepadnavirus.

Acute Disease↗
PubMed1999

TGF-beta2 activates proliferative scar fibroblasts.

BACKGROUND: Cytokines, such as the transforming growth factor beta (TGF-beta) isoforms, have been linked to the formation of proliferative scars. This study examines the stimulating effects of exogenous TGF-beta2 on cultured keloid, burn hypertrophic scar, and normal skin fibroblasts and whether such effects can be suppressed with TGF-beta2 antibody. METHODS: In vitro, the fibroblast-populated collagen lattice (FPCL) is used in the evaluation of fibroblast activation by measuring contraction of the lattice over time. Primary cultures of fibroblasts were grown from keloids, burn hypertrophic scars, and normal skin using standard cell culture techniques. TGF-beta2 (10 ng/ml) was added to each of the three types of cell cultures and placed on prefabricated FPCLs. Each was tested against their normal control counterparts. TGF-beta2 antibody (100 ng/ml) was then placed on the TGF-beta2-treated FPCLs. All lattices were allowed to contract and areas were measured for 5 days. RESULTS: Compared to controls, keloid fibroblasts were most affected by the addition of exogenous TGF-beta2. Normal skin fibroblasts did not show a significant increase in contraction early on, yet a significant difference was seen as time progressed. The addition of TGF-beta2 antibody inhibited the function of keloid and burn hypertrophic scar fibroblasts. It also reversed the increased contraction of the TFG-beta2-treated proliferative scar fibroblasts. CONCLUSION: By utilizing an in vitro model, we have demonstrated that TGF-beta2 antibody reverses the increased contraction of FPCLs by proliferative scar fibroblasts treated with TGF-beta2. This points to a possible treatment modality in patients afflicted with this disfiguring problem.

Antibodies↗
PubMed1999

Exogenous transforming growth factor beta(2) modulates collagen I and collagen III synthesis in proliferative scar xenografts in nude rats.

BACKGROUND: Keloid and hypertrophic scars are fibrous dermal tumors characterized by overabundant collagen deposition. Previous studies demonstrated that exogenous transforming growth factor beta (TGF-beta) might increase collagen production in incisional wound models and in vitro. Using an in vivo model of human scar xenografts maintained in congenitally athymic, asplenic "nude" rats, we examined endogenous TGF-beta(2), collagen I, and collagen III levels in keloids and burn hypertrophic scars treated with TGF-beta(2) and TGF-beta(2) antibody. METHODS: Fresh keloid and burn hypertrophic scar specimens excised from human subjects were explanted to pedicled flaps based on the superficial inferior epigastric vessels in athymic "nude" rats. These flaps were allowed to mature for 3 weeks, after which the scar explants were directly perfused with 200 ng of TGF-beta(2) or 250 microg of TGF-beta(2) antibody daily for 5 consecutive days, then again on Days 10, 15, and 20. Biopsies were taken 30 and 120 days following the initiation of treatment. Immunohistochemical staining was then performed for TGF-beta(2), collagen I, and collagen III. The intensity of staining was quantified. RESULTS: Our results demonstrated that treatment of human proliferative scars with exogenous TGF-beta(2) results in a significant increase in endogenous TGF-beta(2), collagen I, and collagen III production. By contrast, exogenous addition of anti-TGF-beta(2) antibody significantly decreased endogenous TGF-beta(2), collagen I, and collagen III production. CONCLUSION: This study supports a causative role for TGF-beta(2) in the formation of proliferative scars and suggests that TGF-beta(2) antibody may be a new potential antiscarring agent.

Animals↗
PubMed1999

Health promotion versus disease and care: failure to establish "blissful clarity" in British nurse education and practice.

An evaluation which involved documentary analysis, observation and interviews with teachers, students and nurses in four educational institutions, revealed that the interpretation and implementation of a philosophy of health in nursing in the UK has been variable. A small but influential group of teachers saw health as the basis for the curriculum and the way forward for nursing. The new Project 2000 health-based curriculum led some participants to reassess their conception of nursing, but disease and care of the sick remained uppermost. Trained hospital nurses in particular continued to view nursing as primarily concerned with disease treatment. The care model associated with 'New Nursing', rooted in communication and interpersonal relationships, was also apparent particularly among pre- and post-registration students. Health was operationalised as both health education and health promotion ranging from individualised information giving and disease prevention to more participatory forms based on equity and empowerment. Participants' responses to the introduction of health in the curriculum were categorised in one of four ways: pessimism, partisanship, fanschen (to turn over) or marketisation. Their response depended on whether they viewed health as the central nursing philosophy rather than disease or care. On the basis of our findings we propose that these responses give rise to four policy choices for nurses at an individual and group level.

Education, Nursing↗
PubMed1999

latheo encodes a subunit of the origin recognition complex and disrupts neuronal proliferation and adult olfactory memory when mutant.

The Drosophila latheo (lat) gene was identified in a behavioral screen for olfactory memory mutants. The original hypomorphic latP1 mutant (Boynton and Tully, 1992) shows a structural defect in adult brain. Homozygous lethal lat mutants lack imaginal discs, show little cell proliferation in the CNS of third instar larvae, and die as early pupae. latP1 was cloned, and all of the above mentioned defects of hypomorphic or homozygous lethal lat mutants were rescued with a lat+ transgene. lat encodes a novel protein with homology to a subunit of the origin recognition complex (ORC). Human and Drosophila LAT both associate with ORC2 and are related to yeast ORC3, suggesting that LAT functions in DNA replication during cell proliferation.

Amino Acid Sequence↗
PubMed1999

The influence on survival of delay in the presentation and treatment of symptomatic breast cancer.

The aim of this study was to examine the possible influence on survival of delays prior to presentation and/or treatment among women with breast cancer. Duration of symptoms prior to hospital referral was recorded for 2964 women who presented with any stage of breast cancer to Guy's Hospital between 1975 and 1990. Median follow-up is 12.5 years. The impact of delay (defined as having symptoms for 12 or more weeks) on survival was measured from the date of diagnosis and from the date when the patient first noticed symptoms to control for lead-time bias. Thirty-two per cent (942/2964) of patients had symptoms for 12 or more weeks before their first hospital visit and 32% (302/942) of patients with delays of 12 or more weeks had locally advanced or metastatic disease, compared with only 10% (210/2022) of those with delays of less than 12 weeks (P < 0.0001). Survival measured both from the date of diagnosis (P < 0.001) and from the onset of the patient's symptoms (P = 0.003) was worse among women with longer delays. Ten years after the onset of symptoms, survival was 52% for women with delays less than 12 weeks and 47% for those with longer delays. At 20 years the survival rates were 34% and 24% respectively. Furthermore, patients with delays of 12-26 weeks had significantly worse survival rates than those with delays of less than 12 weeks. Multivariate analyses indicated that the adverse impact of delay in presentation on survival was attributable to an association between longer delays and more advanced stage. However, within individual stages, longer delay had no adverse impact on survival. Analyses based on 'total delay (i.e. the interval between a patient first noticing symptoms and starting treatment) yielded very similar results in terms of survival to those based on delay to first hospital visit (delay in presentation).

Adult↗
PubMed1999

Overexpression of c-erbB2 is an independent marker of resistance to endocrine therapy in advanced breast cancer.

The present study investigated the interaction between c-erbB2 overexpression and the response to first-line endocrine therapy in patients with advanced breast cancer. The primary tumours of 241 patients who were treated at first relapse with endocrine therapy were assessed for overexpression of c-erbB2 by immunohistochemistry. c-erbB2 was overexpressed in 76 (32%) of primary breast cancers and did not correlate with any other prognostic factor. The overall response to treatment and time to progression were significantly lower in patients with c-erbB2-positive tumours compared to those that were c-erbB2-negative (38% vs 56%, P = 0.02; and 4.1 months vs 8.7 months, P < 0.001, respectively). In multivariate analysis, c-erbB2 status was the most significant predictive factor for a short time to progression (P = 0.0009). In patients with ER-positive primary tumours treated at relapse with tamoxifen (n = 170), overexpression of c-erbB2 was associated with a significantly shorter time to progression (5.5 months vs 11.2 months, P < 0.001). In conclusion, overexpression of c-erbB2 in the primary tumour is an independent marker of relative resistance to first-line endocrine therapy in patients with advanced breast cancer. In patients with ER-positive primary tumours, the overexpression of c-erbB2 defines a subgroup less likely to respond to endocrine therapy.

Adult↗
PubMed1999

Minimal breast cancer: evaluation of histology and biological marker expression.

Ninety-eight minimal breast cancers (MBCs) diagnosed between 1975 and 1990, and all originally considered to be invasive were found, on review, to form three groups: (a) 28 predominantly invasive carcinomas < or = 10 mm ('predominant invasive'); (b) 48 predominantly ductal carcinoma in situ (DCIS) lesions with definite foci of invasion each < or = 10 mm ('predominant DCIS'); and (c) 22 DCIS without evidence of invasion ('pure DCIS'). Tumour histology and immunohistochemical expression of Ki-67, c-erbB2, p53, oestrogen receptor (ER), progesterone receptor (PR), and Bcl-2 were compared. The major finding was the contrasting features in the two invasive groups, with significant differences in their extent of invasion (P < 0.0001), tumour grade (P = 0.03), DCIS type (P = 0.008) and in marker expression. In the predominant invasive group, the infiltrative component was usually greater than 5 mm, low-grade and associated with well-differentiated DCIS. Expression of Ki-67, c-erbB2 and p53 was generally low, and that of ER, PR and Bcl-2 high. The predominant DCIS group in contrast had a much smaller, commonly high-grade, invasive component, usually with poorly differentiated DCIS and the reverse pattern of marker expression. Although not significant, survival of patients in the predominant invasive group was slightly better. These findings suggest that invasive MBCs should perhaps be treated as separate entities, in order to aid more appropriate selection of treatment.

Biomarkers, Tumor↗
PubMed1999

Students' expectations of postregistration degree programmes.

The needs of postregistration students pursuing degree-linked clinical courses have received little attention and there are few insights concerning their aspirations when they enrol on such courses. Thus the aim of this study was to explore postregistration students' perceptions of the specific needs of their patient/client group and to examine how they envisaged the course on which they had just enrolled might help them to meet these needs in addition to their own requirements for professional and personal development. Data were collected by group interview from 62 students enrolling on eight different postregistration courses, all employed in an acute hospital trust. The results were analysed inductively. They indicated that students had internalized the state of the healthcare market and were keenly aware of the need to fulfil the expectations of employers and the public, while fulfilling their own needs for education and pursuing their own professional and career trajectories. They appeared ambitious and yet appeared to demonstrate empathy for patients and their families and felt a tremendous desire to provide care of a high quality through the optimal development of technical expertise. Students' emphasis on the importance of keeping abreast of technological developments should not be lightly dismissed considering its prominent position within the acute areas where they were employed, especially as it did not replace their desire to promote the caring aspects of their work.

Attitude of Health Personnel↗