PubMed Health⌕ Search

Biomedical subjects

John A Spencer

Publications and source records attributed to John A Spencer.

8 recordsLinked to original sources
PubMed2006

Image guided biopsy in the management of cancer of the ovary.

When used in the context of multidisciplinary team discussion, image guided biopsy using ultrasound (US) or computed tomography (CT) guidance is of value in planning management of women with suspected ovarian cancer and peritoneal carcinomatosis (PC) of uncertain aetiology. It is essential in women believed to have ovarian cancer but with poor performance status or with advanced disease believed beyond the scope of primary cytoreductive surgery for whom staging surgical pathology will not be obtained. It provides a site-specific primary tumour diagnosis in 93% of cases and it should replace diagnostic laparoscopy or laparotomy for this purpose. It allows provision of primary (neoadjuvant) chemotherapy based on a firm histological diagnosis. It is mandatory in women with a history of cancer whose metastases may mimic ovarian cancer (e.g. breast, GI tract, melanoma). More women with prior breast cancer who re-present with peritoneal cancer will have a new gynaecological primary than recurrence of their original primary tumour; the two options require radically different therapies. Finally it is a valuable problem solving tool in situations of diagnostic uncertainty, e.g. unusual imaging patterns of disease such as PC with bilateral solid ovarian masses or non-enlarged ovaries and with an unusual tumour marker profiles suggesting primary tumours outwith the ovary. The technique is simple, safe and effective and can be combined with palliative drainage of ascites at the same procedure.

Biopsy↗
PubMed2005

Quality assessment of internet pharmaceutical products using traditional and non-traditional analytical techniques.

This work investigated the use of non-traditional analytical methods to evaluate the quality of a variety of pharmaceutical products purchased via internet sites from foreign sources and compared the results with those obtained from conventional quality assurance methods. Traditional analytical techniques employing HPLC for potency, content uniformity, chromatographic purity and drug release profiles were used to evaluate the quality of five selected drug products (fluoxetine hydrochloride, levothyroxine sodium, metformin hydrochloride, phenytoin sodium, and warfarin sodium). Non-traditional techniques, such as near infrared spectroscopy (NIR), NIR imaging and thermogravimetric analysis (TGA), were employed to verify the results and investigate their potential as alternative testing methods. Two of 20 samples failed USP monographs for quality attributes. The additional analytical methods found 11 of 20 samples had different formulations when compared to the U.S. product. Seven of the 20 samples arrived in questionable containers, and 19 of 20 had incomplete labeling. Only 1 of the 20 samples had final packaging similar to the U.S. products. The non-traditional techniques complemented the traditional techniques used and highlighted additional quality issues for the products tested. For example, these methods detected suspect manufacturing issues (such as blending), which were not evident from traditional testing alone.

Chromatography, High Pressure Liquid↗
PubMed2003

Periodontal disease among the middle-aged Vietnamese population.

Information about periodontal disease patterns among the populations of developing countries is limited. These populations may illustrate the natural history of the disease owing to low or virtually no access to dental care, contributing to a more complete understanding of the disease process. The present study aimed to describe the patterns of periodontal loss of attachment (LOA) among representative middle-aged Vietnamese adults. A multi-stage, stratified random sampling technique was employed in two randomly selected provinces. The US NIDR protocol with two sites per tooth for the whole mouth, excluding third molars, was used to assess LOA. A total of 575 subjects aged 35-44 years were interviewed and periodontally examined (response 84.6%). Data were re-weighted to reflect the population of the two provinces. Oral hygiene status was poor with high accumulation of plaque and calculus. The prevalence, extent of sites with pockets (PD), recession (GR) and LOA exceeding various thresholds and the severity of LOA were calculated. Almost all subjects presented with at least one site with LOA > or = 2 mm but the higher levels of the disease were skewed. The extent of sites with GR, PD and LOA > or = 4mm was 1.35, 5.04 and 11.81 per cent respectively. More buccal sites had GR, while more mesial sites had PD and LOA. Severity score of LOA was 2.5 (SD: 0.7). LOA of 4+mm were observed more at maxillary molar buccal sites, followed by mandibular incisor mesial sites. LOA was prevalent among middle-aged Vietnamese adults. The loss of periodontal support was positively skewed and varied between teeth and sites.

Adult↗