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Biomedical subjects

M A Henderson

Publications and source records attributed to M A Henderson.

At least 19 recordsLinked to original sources
PubMed1998

Characteristics and treatment of breast cancers 10 mm or less detected by a mammographic screening programme.

BACKGROUND: Small invasive breast cancers up to 10 mm in size have an excellent prognosis and are being detected in increasing numbers by mammographic screening, yet optimal treatment remains controversial. METHODS: A review was made of pathology and treatment data relating to 100 consecutive invasive breast cancers up to 10 mm in size detected among 52,126 women who were screened over a 32-month period. RESULTS: The most common radiological finding was a stellate lesion (44%). Thirty-three cases had an extensive in situ component in addition to the invasive tumour, and included among these were seven ductal carcinoma in situ (DCIS) cases with microinvasion. Of 79 patients who had axillary dissections, seven (9%) were node-positive. Tumours < or = 5 mm were as likely to be node-positive (11%) as those 6-10 mm in size (8%). Positive nodes were found only in patients with more than five nodes excised. Breast conservation surgery was performed in 84% of patients treated by surgeons associated with the programme, and 63% of patients were treated by other surgeons (P = 0.054, exact test). Breast radiation after breast conservation surgery was used in 44% of the cases, but was almost twice as likely to be used if the tumours were > 5 mm (51%) than if the tumours were < or = 5 mm (29%). Adjuvant tamoxifen was given to 61% of the cases. CONCLUSIONS: We found that small invasive breast cancers are commonly treated by breast conservation, which usually includes axillary dissection. Even the smallest may be node-positive, and there is uncertainty about the place of adjuvant radiation therapy and tamoxifen.

Antineoplastic Agents, Hormonal↗
PubMed1997

Audit of colorectal cancer surgery by non-specialist surgeons.

BACKGROUND: Some authorities recommend that colorectal cancer should be treated in specialist units but evidence that non-specialist units demonstrate comparatively poor results may be lacking. METHODS: Between 1987 and 1991, 267 patients were operated on by four general surgeons, none of whom was a specialist in colorectal surgery. Procedure-related complications, postoperative mortality and disease-related survival rates were analysed. RESULTS: There were four cases of intraperitoneal sepsis (1 per cent) and five of 189 patients (3 per cent) had clinical anastomotic dehiscence; there was no case of wound dehiscence. The postoperative mortality rate after elective and emergency surgery was 2 and 13 per cent respectively. The 5-year disease-related survival rate for curative and palliative surgery was 67 and 9 per cent respectively. There were no significant differences between the surgeons. CONCLUSION: Disease-related variables such as early-stage disease and fewer patients presenting as emergencies may have a greater favourable influence on ultimate survival than surgeon-related variables.

Aged↗
PubMed1995

Breast cancer: getting the diagnosis right.

Distinguishing between early breast cancer and benign conditions, which are much more common, can be difficult. Careful clinical examination and directed imaging, supported by fine needle aspiration cytology, provide a high level of diagnostic accuracy.

Biopsy, Needle↗
PubMed1995

Proteolytic activation of bacterial toxins by eukaryotic cells is performed by furin and by additional cellular proteases.

Before intoxication can occur, anthrax toxin protective antigen (PA), Pseudomonas exotoxin A (PE), and diphtheria toxin (DT) must be activated by proteolytic cleavage at specific amino acid sequences. Previously, it was shown that PA and DT can be activated by furin. In Chinese hamster ovary (CHO) cells, wild-type (RKKR) and cleavage site mutants of PA, each administered with a modified form of anthrax toxin lethal factor (the N terminus of lethal factor fused to PE domain III), had the following potencies: RKKR (wild type) (concentration causing 50% cell death [EC50] = 12 ng/ml) > or = RAAR (EC50 = 18 ng/ml) > FTKR (EC50 = 24 ng/ml) > STRR (EC50 = 49 ng/ml). In vitro cleavage of PA and cleavage site mutants of PA by furin demonstrated that native PA (RKKR) and PA with the cleavage sequence RAAR are substrates for furin. To characterize eukaryotic proteases that play a role in activating bacterial toxins, furin-deficient CHO cells were selected after chemical mutagenesis. Furin-deficient cells were resistant to PE, whose cleavage site, RQPR, constitutes a furin recognition site and to all PA cleavage site mutants, but were sensitive to DT (EC50 = 2.9 ng/ml) and PA (EC50 = 23 ng/ml), whose respective cleavage sites, RKKR and RVRR, contain additional basic residues. Furin-deficient cells that were transfected with the furin gene regained sensitivity to PE and PA cleavage site mutants. These studies provide evidence that furin can activate the three toxins and that one or more additional proteases contribute to the activation of DT and PA.

ADP Ribose Transferases↗
PubMed1995

A salaried compensation model for postanesthesia nurses.

Health care organizations involved in innovative and creative work redesign projects may find traditional pay structures inadequate to meet the needs of the changing environment. The idea of salaried compensation for registered nurses is not unprecedented. However, few salaried compensation models for nurses are described in the literature. This article presents a model that we believe will be of particular interest to nurses in PACUs, because its design allows for adequate call coverage plus flexibility in scheduling. In addition, this compensation model eliminates incidental overtime, thus allowing for a more predictable salary budget.

Humans↗
PubMed1995

Use of a laryngeal mask airway in an adult patient with the Hunter syndrome.

The mucopolysaccharidoses are a rare group of diseases. The Hunter Syndrome (mucopolysaccharidosis II) has been classified into severe and mild forms with presentation between the years 2 and 4. Enzyme assays provide the definitive diagnosis. An outstanding concern for the anaesthetist is airway management. The management of a patient with this condition is illustrated with a case report.

Abscess↗
PubMed1993

Extracorporeal shock wave lithotripsy combined with litholytic therapy in the treatment of patients with symptomatic gallstones--the Melbourne experience.

OBJECTIVE: To investigate the role of extracorporeal shock wave lithotripsy using the Dornier MPL9000 lithotripter and adjuvant litholytic therapy in the treatment of symptomatic gallbladder stones. PATIENTS AND METHODS: Between August 1989 and March 1991, 399 patients had their one to three gallbladder stones fragmented by the Dornier MPL9000 lithotripter. Chenodeoxycholic acid alone was used as adjuvant litholytic therapy in the majority. A minority received a combination of chenodeoxycholic acid and ursodeoxycholic acid or ursodeoxycholic acid alone. Patients who died, had cholecystectomies or failed to complete the treatment program were excluded from analysis, leaving a cohort of 287 patients with a follow-up of at least 12 months. This cohort comprised 173 patients with single small stones (20 mm or less in diameter), 32 patients with single large stones (21 mm to 30 mm in diameter) and 82 patients with two to three stones. OUTCOME MEASURES: Patients were followed up by repeated ultrasound examination to monitor the disappearance of fragments from the gallbladder. Stone-free rates, recurrences and complications of treatment were determined. RESULTS: The stone-free rate 12 months after treatment was 37.6% for patients with a single small stone, 3.1% for patients with a single large stone and 18.3% for patients with two to three stones. Of 70 patients with a single small stone who had become stone free at some time during the 12 months after treatment, five (7.1%) experienced recurrence, as did one of the 16 patients (6.9%) with two to three stones. Some 179 patients (44.9%) experienced biliary colic after lithotripsy. Most attacks were mild. Eleven patients (2.8%) developed cholecystitis and nine (2.3%) became jaundiced. Five patients (1.3%) suffered from pancreatitis, of whom one died from severe necrotising pancreatitis. Treatment mortality was 0.25%. Cholecystectomy was needed in 44 patients (11.9%). CONCLUSIONS: Only about 15%-20% of all patients with symptomatic gallbladder stones are suitable for lithotripsy. In this study, only about 28% were stone free after 12 months. As the gallbladder is not removed, stones may re-form. Laparoscopic cholecystectomy and open cholecystectomy by comparison will produce a "stone-free state" in 100% of patients, no matter how many stones are present in the gallbladder, their size, or whether the gallbladder is non-functioning. Consequently, lithotripsy and litholytic therapy are now reserved for those few patients who are unable to tolerate general anaesthesia and cholecystectomy and those who refuse surgery. Even in centres showing the most favourable results, lithotripsy and litholytic therapy will have at best a minor role to play in the overall management of symptomatic gallbladder stones.

Adult↗
PubMed1993

Detection and significance of occult metastases in node-negative breast cancer.

The clinical value of lymph node immunohistochemistry was assessed in 343 consecutive patients with apparently node-negative breast cancer using antimucin monoclonal antibodies BC2, BC3 and 3E1.2. Occult metastases were detected in 41 patients (12 per cent). Although most of these were micrometastatic (< 2 mm in diameter), larger or diffuse deposits were found in ten patients. Blind assessment of repeat haematoxylin and eosin stained sections detected metastases in ten of the 41 patients with occult metastases. After a median follow-up of 79 months, patients with occult metastases had a shorter time to disease recurrence (P < 0.05) but not to death. After adjustment for other prognostic factors, the presence of occult metastases in two or more nodes was the most significant predictor of both disease recurrence (P < 0.01) and death (P < 0.01). When the ten patients with positive haematoxylin and eosin sections were excluded from the analysis, the presence of occult metastases in two or more nodes was still associated with a reduced disease-free interval (P < 0.05) and survival (P < 0.05). Lymph node immunohistochemistry is a simple technique affording more accurate definition of nodal involvement than conventional methods.

Adult↗
PubMed1993

Parental attitudes to presence at induction of paediatric anaesthesia.

Previous studies of parental presence at induction of anaesthesia in children have examined parental reaction to being present and the benefits gained from their presence. This study was undertaken specifically to assess parents' attitudes to being present at induction of their child's anaesthetic. A total of 154 questionnaires were distributed over a two-week period to parents of children presenting to the Day Stay Unit for procedures requiring general anaesthesia. Eighty-eight percent would have liked to be present at induction. Only 41% of parents expected to be present and only 40% of parents were actually present for their child's induction. Of those parents present, 94% felt it helpful to their child, 65% helpful to themselves and 41% helpful to the anaesthetist. No-one felt their presence to have been unhelpful. These results may provide an incentive for anaesthetists to review their current paediatric anaesthetic practices.

Anesthesia↗
PubMed1993

Parathyroid hormone related protein in breast cancers of widely varying prognosis.

Parathyroid hormone related protein (PTHrP) is a novel calcium regulating hormone that may have a significant role in the pathophysiology of breast cancer. We have previously demonstrated a relationship between immunohistochemically detectable PTHrP in primary breast tumours and the subsequent development of bone metastases and hypercalcaemia. The aim of this study was to compare the PTHrP status in the primary tumours from three groups of patients with widely varying prognosis. (1) The favourable outcome group; all patients had a favourable prognosis and minimum 3 years disease free follow up (n = 30). (2) The unfavourable outcome group; all patients presented with localized breast cancer but developed distant disease within 3 years (n = 26). (3) The unfavourable presentation group; all had distant disease at first presentation (n = 26). No differences in PTHrP status of the primary tumour amongst the three patient groups were found (66%, 65% and 61% positive respectively). The development of bone with liver metastases and hypercalcaemia was associated with increased positive PTHrP status of the primary tumor.

Bone Neoplasms↗
PubMed1992

Needle core biopsy of the breast with a spring-loaded device.

Over a 2-year period, 151 outpatients with a palpable breast lump requiring needle core biopsy were randomized to a Tru-Cut 14-G (T14), Bioptycut 14-G (B14) or Bioptycut 18-G (B18) needle. Use of a Biopty gun resulted in less pain than a Tru-Cut needle. An inadequate sample was obtained after two needle passes in 11 of 49 (T14), none of 51 (B14) and two of 51 (B18) patients (chi 2 = 14.6, 2 d.f., P = 0.0007). Tissue samples were assessed by a single pathologist for tissue volume and overall diagnostic value; the B14 group scored better than the B18 and T14 for both of these parameters (P < 0.003). The sensitivities were 68 (T14), 88 (B14) and 96 (B18) per cent (overall chi 2 = 7.3, 2 d.f., P = 0.026). The Biopty gun with a 14-G needle results in a higher sampling success rate, greater diagnostic sensitivity and a better specimen quality than the Tru-Cut, and is much easier to use.

Adult↗