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Biomedical subjects

R Carpenter

Publications and source records attributed to R Carpenter.

At least 37 records · Page 2Linked to original sources
PubMed2001

Does intraductal breast cancer spread in a segmental distribution? An analysis of residual tumour burden following segmental mastectomy using tumour bed biopsies.

INTRODUCTION: Breast-conserving surgery for early breast cancer is now routinely used as an alternative to mastectomy. Despite post-operative radiotherapy, early local recurrence of tumour remains a concern. It has been reported that invasive and in-situ ductal carcinoma spread locally through the ductal tree in a segmental distribution, however, there is no consensus as to the best surgical method to maximize tumour clearance whilst leaving a good cosmetic result. AIM: We aimed to measure the effectiveness of segmental mastectomy (excision of tumour plus associated segmental ductal tissue) in the clearance of different tumour types. Bed biopsy of the excision cavity was employed to assess the rate of incomplete excision or the multifocality of certain breast cancers. METHODS: One hundred and one patients with breast cancers underwent segmental mastectomy and cavity bed biopsies. Specimens were assessed for tumour type and completeness of excision. An excision of the cancer was considered incomplete if the margins were involved or if any of the bed biopsies showed residual or multifocal tumour. RESULTS: A total of 24 patients had incomplete tumour excision. Invasive ductal carcinoma was more likely to be completely excised by segmental mastectomy than invasive lobular carcinoma (P<0.05). Incomplete excision was associated with multifocality and the presence of extensive DCIS. The report of clear pathological margins was significantly more likely to be accurate, as measured by negative bed biopsies, in invasive ductal carcinoma when compared to invasive lobular carcinoma (P<0.05). CONCLUSION: These results support the concept that ductal carcinomas spread locally in a segmental fashion. Patients with invasive ductal carcinomas are more likely to benefit from breast conserving surgery that is tailored to include the associated ductal tissue, in a segmental fashioned excision.

Adult↗
PubMed2001

Report on the development of a procedure to prevent placement of feeding tubes into the lungs using end-tidal CO2 measurements.

OBJECTIVE: To determine the accuracy of a technique using capnography to prevent inadvertent placement of small-bore feeding tubes and Salem sump tubes into the lungs. SETTING: Twelve-bed medical intensive care unit (MICU) in a 557-bed teaching hospital. PATIENTS: A total of 25 ventilated adult MICU patients were studied-5 in phase 1 and 20 in phase 2. DESIGN: Phase 1 tested the ability of the end-tidal CO2 (ETCO2) monitor to detect flow (and thus accurately detect CO2) through small-bore feeding tubes. A small-bore feeding tube, with stylet in place, was placed 5 cm through the top of the tracheostomy tube ventilator adapter in five consecutive patients. The distal end of the feeding tube was attached to the ETCO2 monitor. The ETCO2 level and waveform were assessed and recorded. Because CO2 waveforms were successfully detected, a convenience sample of 20 adult MICU patients who were having feeding tubes placed (13 Salem sump tubes, 7 small-bore feeding tubes) was then studied. The technique consisted of attaching the ETCO2 monitor to the tubes and observing the ETCO2 waveform throughout placement. RESULTS: The study hypothesis was supported. Of the seven small-bore feeding tubes tested, all were successfully placed on initial insertion. Placement was confirmed by absence of an ETCO2 waveform and by radiograph. Of the 13 Salem sump tubes, 9 were placed successfully on first attempt and confirmed by absence of CO2 and by air bolus and aspiration of stomach contents. ETCO2 waveforms were detected with insertion of four of the Salem sump tubes; the tubes were immediately withdrawn, and placement was reattempted until successful. CONCLUSIONS: The technique described is a simple, cost-effective method of assuring accurate gastric tube placement in critically ill patients.

Adult↗
PubMed2001

Improved rat model for cerebral vasospasm studies.

While the rat has been used extensively in subarachnoid hemorrhage (SAH)-cerebral vasospasm studies, concerns exist whether this animal represents a usable model because its time course and pattern of cerebral vasospasm following SAH is not comparable to that observed in man. At present, our knowledge of the rat model is based almost exclusively on studies using a 'single hemorrhage' method. Since there is a positive correlation between severity of cerebral vasospasm, and volume of subarachnoid blood, an obvious question is whether the rat will show modifications in vascular responses when insulted by a second SAH. Here, an SAH was produced in rats using a 'double hemorrhage' method. Following SAH, cerebral arteries showed pathological alterations, significant decreases in luminal perimeter, and increases in arterial wall thickness, over a 7-day post-SAH period. The above vascular features are considered to be indicative of cerebral vasospasm and their presence over a 7-day post-SAH period represents a significant time extension when compared to a single hemorrhage. These modified vascular responses made the double hemorrhaged rat a much-improved animal model.

Animals↗
PubMed2001

Golden jubilee.

Explore the source record for details and available documents.

History, 20th Century↗
PubMed2000

The fall, recovery, orbit, and composition of the Tagish Lake meteorite: a new type of carbonaceous chondrite.

The preatmospheric mass of the Tagish Lake meteoroid was about 200,000 kilograms. Its calculated orbit indicates affinity to the Apollo asteroids with a semimajor axis in the middle of the asteroid belt, consistent with a linkage to low-albedo C, D, and P type asteroids. The mineralogy, oxygen isotope, and bulk chemical composition of recovered samples of the Tagish Lake meteorite are intermediate between CM and CI meteorites. These data suggest that the Tagish Lake meteorite may be one of the most primitive solar system materials yet studied.

Journal Article↗
PubMed2000

Audit of a one-stop breast clinic--revisited.

BACKGROUND: A one-stop diagnostic service has been available for women with symptomatic breast disease at St Bartholomew's Hospital for 5 years and was originally audited in May 1993. In re-auditing the one-stop service our aim was to see if our practice had improved following the original audit and to look at the impact which these changes in practice had made to the service offered to the patient. METHODS: A prospective audit of 4 consecutive clinics was undertaken in November 1997. A total of 300 patients (59 new and 241 follow up) were seen in clinic in this time. The primary outcome measure concerned the completeness of triple assessment in the 40 patients who required one stop investigations, including mammography, ultrasonography and fine-needle aspiration cytology. In addition, mean time to initial consultation and level of awareness of the one-stop facility and its attendant time delay were measured. RESULTS: Of the 300 clinic attendees 40 (38 new, 2 follow-up) had one-stop investigations. As a result of the one-stop service being in practice, 36 patients (90%) had a definitive management decision made at their first outpatient visit. Of these 2 were symptomatic cancers, forming 5% of the workload. A total of 86% of the workload was benign. Four patients (10%) had equivocal results. The mean waiting time from designated appointment until surgical consultation was 36.7 minutes and was disappointingly unchanged from that of the previous audit. However this does not take into account the significant reduction in staffing levels which has occurred between the two periods of assessment. CONCLUSIONS: The initial audit identified a significant problem with time constraints, necessitating that a large number of patients with carcinomas return at a later date for further investigations. Booking only new patients at the beginning of clinic has provided a solution. Disappointingly, our figures do not show a significant improvement in mean waiting time compared with the previous audit, despite allowing GPs greater access of referral. Encouragingly, we have been able to maintain a similar standard of provision of care despite lower staffing levels and to implement the changes suggested by the original audit (thereby closing the audit loop).

Adolescent↗
PubMed2000

Integrin beta1 upregulation in MCF-7 breast cancer cells by angiotensin II.

AIMS: Integrins are a major family of cell adhesion molecules whose function is perturbed in tumour invasion and metastasis. Angiotensin II (A II) is well-known in the systemic control of water and electrolyte homeostasis and haemodynamics, but recent evidence points to an additional local renin-angiotensin system (RAS) with possible long-term trophic effects including carcinogenesis. METHODS: The effect of angiotensin II on MCF-7 human breast cancer cell line integrin expression was evaluated with immunocytochemistry (ICC) and immunoprecipitation (IP). RESULTS: The experiments demonstrated a 1.40 +/- 0.14-fold increase in beta, integrin expression on MCF-7 cells following treatment with A II. CONCLUSIONS: These findings report the first evidence of an association between integrins and the RAS in human breast cancer cells and suggest a novel research avenue for future anti-metastatic strategies, through the manipulation of cell adhesion mechanics, in the management of invasive human breast cancer.

Angiotensin II↗
PubMed2000

Is dissection of the internerve tissue during axillary lymphadenectomy for breast cancer necessary?

AIMS: The study evaluates the necessity of dissecting the tissue between the long thoracic and thoracodorsal nerves (internerve tissue) during axillary dissection in breast cancer surgery. By reviewing the lymph node yield and the metastatic rate in the internerve tissue, we examine whether the internerve tissue could be left in situ to minimize the risk of nerve injury. METHODS: A prospective study was conducted on 30 consecutive women undergoing axillary lymphadenectomy for breast cancer. The internerve tissue remaining was excised separately after a routine axillary dissection and was examined by the same pathologist. RESULTS: Twenty (67%) of 30 internerve specimens contained lymph nodes; the internerve nodes were positive for carcinoma in three cases (10%). In one case the lymph node in the internerve tissue was the only metastatic node in the axilla. CONCLUSIONS: There is a significant incidence of lymph nodes (67%) and axillary node metastases (10%) in the tissue lying between the long thoracic and thoracodorsal nerves. Therefore excision of this internerve tissue is strongly recommended in order to optimize decision making regarding adjuvant treatment and oucome in women with operable breast cancer.

Adult↗
PubMed2000

Antibiotic prophylaxis for post-operative wound infection in clean elective breast surgery.

Antibiotic prophylaxis has been used to good effect in the prevention of post-operative wound infections in patients undergoing gastrointestinal operations. We have assessed the use of a single dose of intravenous antibiotic (Augmentin 1.2 g), given with induction of anaesthesia as prophylaxis, against post-operative wound infection in women undergoing clean, elective breast surgery. Three hundred and thirty-four patients were recruited. Of the 164 receiving antibiotic prophylaxis 29 (17.7%) had wound infections compared with 32 (18.8%) in the placebo group (P=0.79). There were no significant differences in any other post-operative infective complications. Antibiotic prophylaxis is probably not required in clean, elective breast surgery.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed2000

Education provision for surgical senior house officers.

The provision of formal education in surgical SHO training is a requirement for posts to be accredited by postgraduate deans. We carried out a questionnaire survey of surgical SHOs attending a Royal College of Surgeons of England study day to quantify the amount of time given to formal education and supervised operating. We found that 79% of SHOs at district general hospitals and 87.5% at teaching hospitals were provided with a formal education programme. Of these SHOs, 77% were able to attend the teaching on a regular basis. In an average week, 8% of SHOs received no supervised operating experience and 37% had no operations supervised by a consultant. These results suggest that many hospitals fall short of the accepted guidelines on basic surgical training. This issue must be addressed by the Royal Colleges.

Education, Medical, Graduate↗
PubMed1999

Control of organ asymmetry in flowers of Antirrhinum.

Organ asymmetry is thought to have evolved many times independently in plants. In Antirrhinum, asymmetry of the flower and its component organs requires cyc and dich gene activity. We show that, like cyc, the dich gene encodes a product belonging to the TCP family of DNA-binding proteins that is first expressed in the dorsal domain of early floral meristems. However, whereas cyc continues to be expressed throughout dorsal regions, expression of dich eventually becomes restricted to the most dorsal half of each dorsal petal. This correlates with the effects of dich mutations and ectopic cyc expression on petal shape, providing an indication that plant organ asymmetry can reflect subdomains of gene activity. Taken together, the results indicate that plant organ asymmetry can arise through a series of steps during which early asymmetry in the developing meristem is progressively built upon.

Amino Acid Sequence↗