PubMed Health⌕ Search

Biomedical subjects

M M Davies

Publications and source records attributed to M M Davies.

17 recordsLinked to original sources
PubMed2004

Bacillus anthracis contamination and inhalational anthrax in a mail processing and distribution center.

AIMS: Four inhalational anthrax cases occurred in a large mail processing and distribution center in Washington, DC, after envelopes containing Bacillus anthracis spores were processed. This report describes the results of sampling for B. anthracis spores during investigations conducted in October and December 2001. METHODS AND RESULTS: Wet swabs, wet wipes, vacuum sock, and air-filter samples were collected throughout the facility to characterize the extent of building contamination. The results showed widespread contamination of B. anthracis spores, particularly associated with one delivery bar code sorter (DBCS) machine that had sorted the spore-containing envelopes and an area where the envelopes were handled by postal workers. Spore concentrations decreased as distance from the DBCS machine increased, but spores were widely dispersed into surrounding areas. CONCLUSION: The spatial distribution of culture positive samples was closely related to the work areas of the inhalational anthrax cases and supported epidemiological evidence that the workers became ill from exposure to B. anthracis spores in areas where the contaminated envelopes had travelled. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this investigation were used to guide decontamination efforts and provided baseline spore concentrations for follow-up measurements after the building had been cleaned. Implementing methods to reduce aerosolization and dispersion of dust within the facility would reduce postal workers' potential exposures to bioterrorism agents.

Air Pollution, Indoor↗
PubMed2002

Effect of manipulation of primary tumour vascularity on metastasis in an adenocarcinoma model.

One explanation for the clinical association between tumour vascularity and probability of metastasis is that increased primary tumour vascularity enhances haematogenous dissemination by offering greater opportunity for tumour cell invasion into the circulation (intravasation). We devised an experimental tumour metastasis model that allowed manipulation of primary tumour vascularity with differential exposure of the primary and metastatic tumour site to angiogenic agents. We used this model to assess the effects of local and systemic increases in the level of the angiogenic agent basic fibroblast growth factor on metastasis. BDIX rats with implanted hind limb K12/TR adenocarcinoma tumours received either intratumoural or systemic, basic fibroblast growth factor or saline infusion. Both intratumoural and systemic basic fibroblast growth factor infusion resulted in significant increases in tumour vascularity, blood flow and growth, but not lung metastasis, compared with saline-infused controls. Raised basic fibroblast growth factor levels and increase in primary tumour vascularity did not increase metastasis. The clinical association between tumour vascularity and metastasis is most likely to arise from a metastatic tumour genotype that links increased tumour vascularity with greater metastatic potential.

Adenocarcinoma↗
PubMed2001

Continuous angiotensin II infusion increases tumour: normal blood flow ratio in colo-rectal liver metastases.

Insufficient blood flow within colo-rectal hepatic metastases is a factor which may limit drug delivery to, and thus the response of, these tumours to regional chemotherapy. Loco-regional flow may be manipulated pharmacologically to enhance the tumour blood flow relative to that of the normal liver. However, as yet, only transient effects have been studied. Patients receiving regional chemotherapy for unresectable hepatic disease were given a 45 min regional infusion of the vasoconstrictor Angiotensin II. Intrahepatic blood flow distribution was assessed serially by Positron Emission Tomography (PET) imaging together with the trapping tracer copper(II) pyruvaldehyde bis(N-4-methylthiosemicarbazone) (Cu-PTSM) labelled using copper-62. Eleven lesions in nine patients were studied, with no adverse effects. Prior to Angiotensin II administration tumour blood flow was generally found to be greater than that of liver (10/11 lesions; 8/9 patients; median TNR 1.3, iqr 0.9-2.5). A significant increase in relative flow to tumour was seen in response to 10 min Angiotensin II infusion in most cases (7/11 lesions; 7/9 patients; median TNR 2.1, iqr 1.4-4.1; P = 0.008), which appeared to be sustained throughout the 45 min infusion period (median TNR 1.85, iqr 1.3-3.8; P = 0.03). These effects were accompanied by transient elevation of mean arterial pressure, but no change in pulse rate. These observations suggest that prolonged regional vasoconstrictor administration could prove useful in the management of unresectable colo-rectal hepatic metastases, and that further development of vascular manipulation to enhance tumour targeting and drug delivery is warranted.

Angiotensin II↗
PubMed2001

62Cu-PTSM and PET used for the assessment of angiotensin II-induced blood flow changes in patients with colorectal liver metastases.

The aim of this study was to establish a quantitative positron emission tomography (PET) method for investigating angiotensin II (AII)-induced changes in blood flow distribution in the liver. This was in order to evaluate the role of vascular manipulation applied to locoregional chemotherapy treatment in patients with colorectal liver metastases. The tracer selected was copper-62 (II) pyruvaldehyde bis-(N4-methyl)thiosemicarbazone (62Cu-PTSM), which exhibits high first-pass extraction and tissue retention following intra-arterial administration. The short half-life of the tracer and its availability from a 62Zn/62Cu generator enabled short-interval repeat PET scans on patients in a single imaging session. Distribution of tracer within the liver was imaged in a single view using a PET camera with rotating large-area detectors. By optimisation of the acquisition protocol, it was possible to acquire sufficient data to produce good-quality images and to quantify tracer uptake with an accuracy of <10%. Reproducibility of the imaging method was assessed in a single patient in whom three consecutive 62Cu-PTSM PET scans were obtained, and in whom no vascular manipulation was performed. Sets of scans (before, during and immediately after a 45-min AII infusion) were obtained in nine patients to assess blood flow changes associated with prolonged vascular manipulation. Significant individual responses, varying in both the magnitude and the duration of flow change, were observed in the majority of cases (7/11 lesions; 7/9 patients). These findings illustrate the potential of 62Cu-PTSM and PET for pharmacological studies. The wide range of individual patient responses to AII infusion suggests that PET blood flow assessment would be of value for selecting patients in whom this procedure may be effective.

Algorithms↗
PubMed2001

The maternity information concerns of Somali women in the United Kingdom.

AIMS: The aims of the study were to explore the maternity information concerns of a group of Somali women in a Northern English city and to investigate the relationships of these women with maternity health professionals. BACKGROUND: The Somali community is one of the most established ethnic minorities in the United Kingdom (UK). The health needs of this group and in particular, the information needs of Somali women with respect to pregnancy, childbirth and post-natal care are poorly understood. To facilitate information provision to birthing mothers and to support maternal decision-making among minority ethnic women, research is required to understand and identify their information needs. METHODS: A user-centred study utilizing a focus group and semi-structured interviews with English-speaking and non-English speaking Somali women was conducted in a large English city. Discussions were audiotaped, translated, transcribed and then analysed using a variation of the constant comparative METHOD: Themes and categories were identified across transcripts during data collection and analysis and appropriate quotations are used to illustrate all themes. FINDINGS: Major findings that emerged from the analysis related to contact with health professionals, language support and information and satisfaction with health professionals. The findings indicate key maternity information concerns of Somali women with regard to maternity issues and have a number of implications for midwifery and nursing practice. CONCLUSIONS: Poor communication between the non-English speaking Somali women and health workers was perceived as an underlying problem in seeking information. Fears about misinterpretation and confidentiality, limit the usefulness of interpreters. The Somali women perceived that they were denied information due to punitive attitudes and prejudiced views among health professionals.

Adult↗
PubMed2000

Plasma vascular endothelial but not fibroblast growth factor levels correlate with colorectal liver mestastasis vascularity and volume.

The extent to which plasma levels of angiogenic factors in healthy individuals and tumour volume-related variations in colorectal cancer affect the accuracy of circulating angiogenic factors as predictors of colorectal cancer vascularity is unknown. We used enzyme-linked immunosorbant assay to measure plasma vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) levels in colorectal liver metastasis (CLM) patients, and 'no cancer' controls. CLM volume was determined from computerized tomography scans, and tumour vessel count and vessel volume from anti-endothelial antibody-stained biopsies. There was a significant (P= 0.03) increase in plasma VEGF level in 29 CLM patients (median 180.3 pg/ml(-1), iqr 132.5-284.8 pg/ml(-1) compared with 19 controls (median 125.8 pg/ml(-1), iqr 58.2-235.9 pg/ml(-1). There were significant correlations between plasma VEGF and tumour vessel count (r = 0.66, P = 0.03), tumour vessel volume (r= 0.59, P = 0.03), and CLM volume (r= 0.53, P = 0.03). A VEGF level in the upper quartile of the plasma VEGF distribution had a 70% sensitivity and 75% specificity in predicting an upper quartile liver metastasis tumour vessel count. No relation was identified between CLM and plasma bFGF levels. Plasma VEGF level predicted CLM vascularity, despite an overlap with normal levels and tumour volume-related variations.

Biomarkers, Tumor↗
PubMed1999

Colorectal liver metastasis thymidylate synthase staining correlates with response to hepatic arterial floxuridine.

We assessed whether intensity of colorectal liver metastasis staining with the thymidylate synthase (TS) antibody TS106 predicted response to hepatic arterial infusion (HAI) of floxuridine chemotherapy. Liver metastasis biopsies were taken during laparotomy for hepatic arterial cannulation and stained using the TS106 monoclonal antibody. Staining intensity was designated at histological examination by two independent assessors as either "high" or "low." Patients were treated by HAI, and liver metastasis response was assessed by comparison of computed tomography scan tumor volume before and after 4 months of treatment. A significant correlation (Fisher's exact test, P = 0.01) was noted between partial response to HAI and TS106 staining intensity in patients with colorectal liver metastases. Seventy-five percent of patients with evidence of a partial response had low TS staining compared with 29% of nonresponders. There was a significant difference (Fisher's exact test, P = 0.01) in the proportion of low (9 of 16) compared with high (3 of 20) TS staining tumors in which a partial response occurred. There was no significant difference (logrank test, P = 0.4) in survival from hepatic cannulation and HAI treatment of high (median, 322 days; interquartile range, 236-411) compared with low (median, 335 days; interquartile range, 301-547) TS staining patients. This study demonstrates an inverse correlation between TS immunohistochemical staining intensity in colorectal liver metastases and response to HAI. The results suggest that a prospective assessment of TS staining intensity in colorectal liver metastases would be useful to determine whether this method can be used to define patients who will benefit from HAI chemotherapy.

Aged↗
PubMed1998

Management of symptomatic locoregional recurrence during regional chemotherapy for colorectal liver metastases.

BACKGROUND: The incidence of symptomatic locoregional recurrence is doubled in patients receiving regional chemotherapy with hepatic arterial floxuridine infusion (HAI) compared with that in those with colorectal liver metastases treated by symptom control. This study assessed the management of symptomatic locoregional recurrence in HAI-treated patients with colorectal liver metastases. METHODS: A retrospective review of all patients with colorectal liver metastases treated by HAI in one hospital over a 10-year period was carried out and the management of those who developed symptomatic locoregional recurrence was studied. RESULTS: Twenty-three (14 per cent) of 166 HAI-treated patients with colorectal liver metastases developed symptoms of locoregional recurrence. Liver metastases were responding to HAI at the onset of symptoms in 19 (ten abdominal, nine pelvic recurrence) of the 23 patients. Resection of abdominal recurrence was possible in seven of the ten patients, with a median hospital stay of 14 days; there was one perioperative death. Resected patients survived a median of 15 months after resection of the recurrence, with five of seven remaining free of symptoms of locoregional recurrence. In contrast, six of nine HAI-responding patients with pelvic recurrence treated by external beam radiotherapy died from uncontrolled symptomatic pelvic disease. CONCLUSION: Resection of abdominal recurrence achieved worthwhile palliation in patients with HAI-controlled liver metastases, but palliation of pelvic recurrence by irradiation was unsatisfactory.

Abdominal Neoplasms↗
PubMed1996

The role of the Davis graft technique in the treatment of chronic post-mastoidectomy otorrhoea.

The effect of grafting mastoid cavities with small Davis cutaneous pinch grafts was assessed in 15 patients. Following revision of the cavity and Davis pinch grafting the resultant cavity was completely dry in 13 patients (87%) over a period ranging from 1 to 30 months with a mean of 7.3 months, with five becoming dry within 1 month. Patient satisfaction with respect to reduction in discharge and smell was excellent (87%). We believe that the Davis graft technique has a beneficial role in persistent post-mastoidectomy otorrhoea especially when previous standard revision techniques have failed.

Adolescent↗
PubMed1986

Care by parents of their children in hospital.

A care by parent option was introduced into a general paediatric ward without any additional finance or facilities. Most parents coped successfully and were grateful for the opportunity of caring for their children. All believed that their children benefited from their active involvement. The nurses believed that their role was enhanced and their job satisfaction increased. This system offers advantages and could become more generally used in paediatric wards in Britain.

Adolescent↗
PubMed1986

Parental involvement in the lives of children in hospital.

A care by parent scheme was established in the children's department of a university hospital. It was seen as the natural extension of the increased involvement of parents in the care of their children in hospital. A structured observational study was carried out to monitor its effect on the lives of child patients. Children in the scheme spent far less time awake alone, cried less, and slept less than those nursed unaccompanied. They had far more social interaction with a smaller number of adults, most of their contacts being with family members rather than hospital staff. Children with a resident parent but outside the scheme were generally in an intermediate position on these factors.

Adult↗
PubMedDate not supplied

3D GPS mapping of land contaminated with gamma-ray emitting radionuclides.

Two studies are given in this paper. Both studies use a combined gamma sensing and global positioning system to monitor land contaminated with gamma emitting radioisotopes. The first is the 3D profiling a large (100m x 200m x 15m) tip of the residue from radium extraction processing. The second is the dynamic monitoring of beaches to locate and recover small particles of radioactive material.

Geographic Information Systems↗
PubMedDate not supplied

Laparoscopic surgery for colorectal cancer: the state of the art.

Laparoscopic techniques have expanded since their introduction 15 years ago. The laparoscopic approach for colorectal surgery has been slower to develop than other fields of surgery. However, this approach does provide significant benefits for colorectal resection, although concerns regarding the ability to satisfy oncological criteria have restricted its use in the past. This review studies the published data on the use of laparoscopic surgery for colorectal cancer including the short- and long-term outcomes. New long-term outcome data is now available which is likely to encourage the use of this technique for colon cancer resection. Laparoscopic rectal cancer resection is also discussed including the more limited outcome data that is available.

Clinical Competence↗