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Biomedical subjects

G B Mann

Publications and source records attributed to G B Mann.

At least 19 recordsLinked to original sources
PubMed2006

Targeting lymphangiogenesis to prevent tumour metastasis.

Recent studies involving animal models of cancer and clinicopathological analyses of human tumours suggest that the growth of lymphatic vessels (lymphangiogenesis) in or nearby tumours is associated with the metastatic spread of cancer. The best validated molecular signalling system for tumour lymphangiogenesis involves the secreted proteins vascular endothelial growth factor-C (VEGF-C) and VEGF-D that induce growth of lymphatic vessels via activation of VEGF receptor-3 (VEGFR-3) localised on the surface of lymphatic endothelial cells. In this review, we discuss the evidence supporting a role for this signalling system in the spread of cancer and potential approaches for blocking this system to prevent tumour metastasis.

Animals↗
PubMed2005

Quality of care for women presenting with benign breast conditions.

The aim of the study was to investigate the management of women with benign breast problems. A consecutive sample of women (n = 194) was assessed who presented to public or private sector providers. The main reasons for referral were breast lumps (62%); 56% of women who attended the public sector did not receive any recommendation compared to 40% who attended the private sector and clinical/general practitioner reviews were recommended to more women in the private sector (54%). Reasons for the discrepancy between public and private patients require further investigation.

Australia↗
PubMed2005

Gastrointestinal stromal tumour treated with neoadjuvant imatinib.

This report describes a case of unresectable primary gastrointestinal stromal tumour (GIST) treated with imatinib on a neoadjuvant basis, before subsequent successful surgical resection. After six months of imatinib, computed tomography and positron emission tomography imaging demonstrated a significant size reduction and complete metabolic response to treatment, rendering the tumour resectable. Mutational analysis showed an activating KIT mutation in exon 11. The pathological appearance of the resected tumour was heterogeneous with extensive necrosis, cystic and myxoid change, extensive hypocellularity, and patchy foci of residual viable tumour. The implications for this management option of radiological, pathological, and molecular assessment are discussed.

Aged↗
PubMed2003

Carbon localisation of impalpable breast lesions.

BACKGROUND: Hookwire localisation (HL) is the most widely used technique for excision of impalpable breast lesions. This method has several drawbacks, particularly with logistics. Carbon localisation (CL) is an alternative procedure which is logistically superior to HL, but comparisons of accuracy and costs have not been reported. METHODS: A consecutive case series of all patients from Northwestern BreastScreen undergoing either CL or HL between January 1999 and March 2001. FINDINGS: Of 511 procedures, 219 CLs and 292 HLs were performed. The accuracy of excision did not vary significantly. Where a preoperative diagnosis of malignancy had been made by percutaneous needle biopsy (PNB), the margins were <1mm in 27 of the CL group (18.9%) and 21 of the HL group (29.2%) (P=0.087). Cost analysis was very favourable for CL performed concurrently with PNB since the costs were incremental. INTERPRETATION: At service delivery level, CL is an accurate alternative to HL with better logistics and favourable costs. Nationally, it has the potential to improve the cost effectiveness of breast screening programmes.

Aged↗
PubMed2001

Immunohistochemically detected micrometastases of the lymph nodes in patients with gastric carcinoma.

BACKGROUND: Lymph node status is a major determinant of disease recurrence after patients undergo curative resection for gastric carcinoma. A proportion of patients without lymph node metastasis develop systemic recurrences. Recent studies in a range of solid tumors have found a high incidence of micrometastases in the regional lymph nodes of patients with apparently negative lymph nodes. In patients with breast and colorectal carcinoma, the presence of micrometastases has been associated with a poorer prognosis. In patients with gastric carcinoma, the significance of micrometastases in lymph nodes remains controversial. Most published reports on this subject suffer from the problems of small sample size and selection bias. METHODS: One hundred seven patients with pathologic T2N0M0 (tumor invades muscularis propria or subserosa [T2], no regional lymph node metastasis [N0], and no distant metastasis [M0]; pT2N0M0) gastric carcinoma who underwent gastric resection between 1984 and 1990 at the National Cancer Center Hospital were studied. Two consecutive sections were newly prepared from each lymph node for hematoxylin and eosin staining and immunohistochemical staining (IHC) with antibody against cytokeratin. Associations between clinicopathologic factors and the presence of micrometastases as well as micrometastases and survival were sought. RESULTS: Micrometastases were identified in 38 of 107 patients (35.5%) and in 87 of 4484 lymph nodes (1.94%) by IHC. The incidence of micrometastases was significantly higher in patients with infiltrative tumors than in patients with expansive, growing tumors (P = 0.02). Other clinicopathologic findings had no statistically significant correlation with the incidence of micrometastases. The 5-year survival rates of patients with and without micrometastases were 94% and 89%, respectively. Similarly, the 10-year survival rates were 79% and 74%, respectively. The survival curves of patients with or without micrometastasis were nearly superimposed (P = 0.86). CONCLUSIONS: The presence of immunohistochemically detected micrometastases in the regional lymph nodes did not affect the survival of Japanese patients with pT2N0M0 gastric carcinoma who had undergone gastrectomy with D2 lymph node dissection.

Adult↗
PubMed2001

Utilization of evidence-based teaching in U.S. dental hygiene curricula.

PURPOSE: The purpose of this research was to survey U.S. dental hygiene program directors to determine: (1) demographic information, (2) specific Evidence-Based (EB) student instruction methods used, (3) if and how programs use an EB philosophy, (4) perceptions of faculty skills in incorporating EB instruction, and (5) opinions and attitudes regarding future need to incorporate EB philosophies in dental hygiene education. METHODS: Data were gathered by surveying all 235 United States dental hygiene program directors in 1999. The survey included 20 closed items and 1 open-ended item. Initially, the survey was pilot tested using a convenience sample of seven U.S. dental hygiene program directors. A final, revised survey was mailed to the cohort population. A response rate of 70% (n = 164) was achieved after two mailings, and responses were analyzed using descriptive statistics. RESULTS: The demographic results of this study revealed the majority of respondents were from associate degree/certificate dental hygiene programs (77%). Results revealed that most dental hygiene programs are beginning to include some fundamental EB concepts and skills into their curriculum, primarily by incorporating analysis of scientific literature. Most programs provide students with formal library orientation (88%), instruct students in the use of library indices or library databases (86%), and teach the use of the Internet for conducting literature searches (79%). Respondents indicated the major barriers for fully incorporating an EB approach in their dental hygiene program were: lack of faculty skills (37%), no available time (34%), lack of financial resources (33%), and lack of technical support (28%). CONCLUSION: Findings of this study suggest dental hygiene educators have made small strides in creating an EB philosophy dental hygiene curriculum. However, the future of dental hygiene education must address the need for faculty development and training in areas such as computer utilization in core dental hygiene courses, strategies to improve the curriculum to stimulate students' critical thinking skills, and to develop educators' skills in the use of evidence for clinical decision-making.

Attitude of Health Personnel↗
PubMed1999

Six-year follow-up of patients with microinvasive, T1a, and T1b breast carcinoma.

BACKGROUND: Management of patients with breast cancers < or = 1 cm remains controversial. Reports of infrequent nodal metastases in tumors < or = 5 mm has led to suggestions that axillary dissection should be selective, and that tumor characteristics should guide adjuvant therapy. METHODS: A retrospective review of 290 patients with breast cancer 1 cm in size or smaller from 1989 to 1991 was done. Distant disease-free survival (DDFS) was the primary outcome measure. RESULTS: There were 95 T1a (< or = 5 mm) and 196 T1b (6-10 mm) cancers. Nodal metastases were found in 8 T1a and 26 T1b tumors. Larger size, poorer differentiation, and lymphovascular invasion (LVI) were associated with more nodal metastases, but none of these trends reached statistical significance. The 6-year DDFS was 93% for node-negative and 87% for node-positive patients (P = .02). Overall, breast cancers with poorer differentiation and LVI trended toward a poorer outcome. For patients with node-negative tumors, LVI was associated with a poorer outcome (P = .03). The size of the primary tumor was not predictive of outcome. There were no nodal metastases or recurrences in the 18 patients with microinvasive breast cancer. CONCLUSIONS: Lymph node status is the major determinant of outcome in breast cancers 1 cm in size or smaller. Accurate axillary assessment remains crucial in management of small breast cancer.

Adult↗
PubMed1999

Adult soft tissue sarcoma.

BACKGROUND: Soft tissue sarcomas (STS) are a group of anatomically and histologically diverse tumours. They account for about 1% of adult malignancies, and about 50% of patients diagnosed with sarcoma eventually die of the disease. These tumours are grouped together because of shared biological characteristics and treatment responses. METHODS: A review of the key literature on STS was undertaken, complemented by data taken from the prospectively accumulated database of 3442 patients treated for STS at Memorial Sloan-Kettering Cancer Center (MSKCC) from July 1982 to December 1997. RESULTS: Despite advances in knowledge of the molecular genetics of STS, the aetiology in most cases remains elusive. Management has been gradually refined over the last two decades. Core biopsy usually provides enough material for diagnosis. Computed tomography and magnetic resonance imaging provide a similar amount of information, which is usually adequate for surgical planning. Amputation as standard treatment for extremity lesions has been replaced by limb-sparing surgery in about 90% of patients. The role of adjuvant radiation has been further defined: it has been shown to be unnecessary for completely excised tumours less than 5 cm in diameter, but effective in decreasing local recurrence for others. Adjuvant chemotherapy has been controversial for many years. Recent meta-analysis of randomized trial results has found a small reduction in local and distant relapse, and a trend to better overall survival. Recurrent or metastatic disease should be completely excised if possible. CONCLUSIONS: Soft tissue sarcoma requires multidisciplinary care tailored to the individual patient and tumour for optimal results.

Adult↗
PubMed1998

Breast cancer genes and the surgeon.

Two genes, called BRCA-1 and BRCA-2, have been identified that appear to be responsible for the majority of familial breast cancer syndromes. These genes now play a prominent role in the practice of the surgeon treating breast cancer. Additional genes, PTEN (Cowden disease), MSH1 or MLH2 (HNPCC), and p53 (Li-Fraumeni syndrome) are responsible for other breast cancer syndromes but have not yet entered the clinical arena on a large scale. The risk of breast and ovarian cancer by age 70 in a BRCA-1 mutation carrier is estimated at 55-75% and 16-26 %, respectively, overall, and as high as 87% and 44% in those with a strong family history. The cancer risks associated with BRCA-2 mutations appear to be somewhat lower than those of BRCA-1. BRCA mutations show a strong founder effect. This is best recognized in the Ashkenazi Jewish community, in which the incidence of one of three characteristic mutations is about 2%. In other ethnic groups the pattern of mutations is different, with over 100 distinct mutations throughout the genes having been described. Most mutations so far have been frame-shift or mis-sense mutations, although large deletions have also been described. Thus, in most situations, assessment of the whole coding sequence is required to confirm or exclude a mutation. Guidelines to suggest who is likely to be a mutation carrier are being clarified, but the appropriate management of someone who tests positive remains difficult. Prophylactic mastectomy and oophorectomy are likely to offer substantial gains in life expectancy to mutation carriers, especially for young women with a strong family history. Unfortunately, there are no currently available strategies to eliminate the risk of breast or ovarian cancer. The psychological impact of testing also remains poorly understood, and the danger of various forms of discrimination remain. These factors must be clearly understood by all parties prior to testing. The process of a dynamic, interactive informed consent--much more than a simple printed document--and also counseling are central to the testing process.

Breast Neoplasms↗
PubMed1998

Emerging role of laparoscopy in the diagnosis of lymphoma.

PURPOSE: The results of laparoscopic procedures on patients with suspected or known lymphoma were analyzed to review the application and define the role of laparoscopy in lymphoma. PATIENTS AND METHODS: The hospital records of 94 patients who underwent 101 procedures between June 1993 and October 1996 were reviewed for demographic and clinicopathologic information. RESULTS: The procedure was diagnostic in 85 patients, either at primary presentation (48 patients), possible relapse (21 patients), in the course of treatment (eight patients), or of a liver lesion (eight patients). In the remaining 16 patients, it was used to stage possible intraabdominal disease. Twenty-seven patients had a previous unsuccessful diagnostic procedure. There were no operative deaths and eight postoperative complications (8%). The laparoscopy revealed non-Hodgkin's lymphoma (NHL) in 48 patients, Hodgkin's disease (HD) in 14 patients, other neoplastic conditions in six patients, and benign conditions in 33 patients. There was adequate information in all procedures in which lymphoma was diagnosed for treatment decisions. There was one false-negative and one nonresult for technical reasons. Ten patients commenced chemotherapy before discharge after a median delay of 3.5 days. In five of 24 patients (21%) with recurrent or persistent lymphoma, the precise diagnosis was significantly different from the original one. CONCLUSION: From our experience, laparoscopy can safely provide tissue samples of suspected lymphoma for full diagnostic analysis. It should be considered when percutaneous biopsy is not technically possible, when chromosomal or genetic analysis is needed for treatment decisions, or when the results of percutaneous biopsy are inadequate to make therapeutic decisions.

Abdominal Neoplasms↗
PubMed1998

Clinical evaluation of two carbamide peroxide tooth-whitening agents.

A blinded study was conducted to evaluate the efficacy and safety of a dentist-prescribed, accelerated carbamide peroxide tooth-whitening system. Fifty-one patients with discolored teeth completed a clinical trial using an overnight bleaching regimen. One group used an experimental bleaching (whitening) regimen with 10% carbamide peroxide bleaching paste, and another group used the Colgate Platinum Professional Overnight Whitening System. The study included an initial 1-week control/compliance phase using a placebo gel, followed by a 1-week active phase using the assigned bleaching agent. The shade of each participant's maxillary anterior teeth was evaluated by 2 trained and calibrated evaluators at the start of the control/compliance phase, the beginning of the active phase, and days 3, 5, and 7 of the active phase. A value-oriented Vita shade guide with 16 rankings was used to measure color changes, and the number of shade guide units of change (delta sgu) was calculated. Potential side effects, such as tooth hypersensitivity and gingival irritation, also were assessed at each recall examination, as well as recorded by the patients in their daily diaries. At the end of the 7-day active phase, the mean delta sgu for the group using the experimental bleaching agent was 7.1 +/- 2.4, and for the Colgate Platinum Overnight group, the delta sgu was 7.5 +/- 2.2. There were no statistically significant (p > or = 0.05) differences between the results of both groups at the 0-, 3-, 5-, and 7-day evaluations. After 7 days, the change in shade guide units for both groups ranged from 3 to 13 units, far exceeding the minimum required change by the American Dental Association Guidelines (delta sgu = 2 units) for demonstrating efficacy. There was no statistical difference in the whitening achieved at day 5 vs. day 7 for either tooth-whitening group. There were no notable changes in any gingival, bleeding, or plaque indexes for the 50 patients completing the active phase. The number of days of mild tooth sensitivity during the active phase was 0.9 +/- 1.3 days for the experimental agent group and 1.1 +/- 1.5 days for the Colgate Platinum group.

Adolescent↗
PubMed1996

Clinical evaluation of a samarium compound filter and E-speed film.

Producing radiographs of good diagnostic quality while keeping the dose as low as possible is the goal of the dental radiographer. Rare earth compound filters reduce the dose, but few clinical studies have evaluated the diagnostic yield. The diagnostic quality of a samarium compound filter used with E-speed film was compared with that of a conventional aluminum filter used with E-speed film. Bitewing projections with the test and standard filters were exposed for 39 patients. Agreement was evaluated with kappa statistics. The results indicated a substantial level of agreement between the two filter types. The combination of samarium compound filter and E-speed film appears to be a good mechanism for achieving dose reduction without compromising the diagnostic yield of the film.

Aluminum↗