Search PubMed⌕ Search

Biomedical subjects

S M Williams

Publications and source records attributed to S M Williams.

At least 217 records · Page 12Linked to original sources

Pilo-sebaceous duct physiology. III. Observations on the number and size of pilo-sebaceous ducts in acne vulgaris.

We have used surface microscopy to measure the pil-sebaceous duct orifices at different sites in 150 subjects. Our data have shown that there are more pilo-sebaceous units on the face compared to the back and that these exists are smaller on the face. Despite the small exit the sebum excretion rate per gland on the forehead was not significantly different from that on the back. Thus the number of pilo-sebaceous duct units and the pilo-sebaceous canal exit size are possible factors in the localization of acne.

Acne Vulgaris↗

Bile duct carcinoma associated with chronic ulcerative colitis.

Patients with chronic ulcerative colitis are prone to a variety of liver disorders. This case report illustrates development of bile duct carcinoma in a patient with long-standing inactive colitis. The report emphasizes the association of chronic ulcerative colitis with bile duct carcinoma and discusses the radiologic preoperative evaluation of the ulcerative colitis patient who develops jaundice.

Adenocarcinoma↗

Double versus single contrast gastrointestinal radiology.

With experience, air contrast examination of the esophagus, stomach, and duodenum can be performed routinely as quickly and easily as the standard UGI. The air contrast examination is superior for detection of small gastric polyps and the Japanese have found it superior for detection of early carcinoma. The postoperative stomach and the fundus and cardia are most easily examined by air contrast. Clear superiority in the diagnosis of peptic ulcers and peptic esophagitis has not been proved. The most accurate routine examination may be a multiphasic or combined approach utilizing air contrast views as well as filled compression views and careful fluoroscopy. With respect to the colon, we do not suggest that air contrast BE must be done exclusively. However, it is superior for the detection of polyps and small carcinomas. The technique should be available in all radiology departments and should be an integral part of the evaluation of patients at increased risk of developing carcinoma. This includes patients over 40 years of age, with chronic ulcerative colitis, familial multiple polyposis or Gardner's syndrome, family history of inherited cancer, and medical history of adenomatous polyps, colorectal cancer, or female genital cancer. In addition, air contrast enema should be utilized for the sensitive and accurate evaluation of early inflammatory bowel disease. Finally, with respect to the colon examination one fact must be stressed. Irregardless of full column or air contrast method, most missed lesions are due to poor bowel preparation, poor technique, or perceptive error by the radiologist. There can be no substitute for a clean colon, meticulous attention to technical details, and careful review of the radiographs.

Air↗

Recognition and prevention of barium enema complications.

The barium enema is a safe and accurate diagnostic study of the colon but, in rare cases, complications may result. Many of these can be prevented by proper equipment and careful attention to technique. When a complication does occur, prompt recognition and management is vital in decreasing morbidity and mortality. Perforation of the bowel is the most frequent serious complication, occurring in approximately 0.02% to 0.04% of patients. Rarely the colon may burst due to excessive transmural pressure alone. However, a colon weakened by iatrogenic trauma or disease is more likely to perforate during an enema than is a normal healthy bowel. Injury to the rectal mucosa or anal canal due to the enema tip or retention balloon is probably the most common traumatic cause of barium enema perforation. Inflation of a retention balloon within a stricture, neoplasm, inflamed rectum, or colostomy stoma is particularly hazardous. Recent deep biopsy or polypectomy with electrocautery makes the bowel more vulnerable to rupture. The tensile strength of the bowel wall is impaired in elderly patients, patients receiving long-term steroid therapy, and in disease states including neoplasm, diverticulitis, inflammatory bowel disease, and ischemia. Intraperitoneal perforation leads to a severe, acute peritonitis with intravascular volume depletion. The ensuing shock may be rapidly fatal. Prompt fluid replacement and laparotomy are essential. If the patient survives the initial shock and sepsis, later complications caused by dense intraperitoneal adhesions may develop. Extraperitoneal perforation is usually less catastrophic but may result in pain, sepsis, cellulitis, abscess, rectal stricture, or fistula. Intramural extravasation often forms a persistent submucosal barium granuloma which may ulcerate or be mistaken for a neoplasm. The most dramatic complication of barium enema is venous intravasation of barium. Fortunately, this is quite rare as it may be immediately lethal. Most cases have been attributed to trauma from the enema tip or retention balloon, mucosal inflammation, or misplacement of the tip in the vagina. Bacteremia has been found in as many as 23% of patients following barium enema and, in rare cases, may cause symptomatic septicemia. Other less common complications include barium impaction, water intoxication, allergic reactions, and cardiac arrhythmias. Preparatory laxatives and cleansing enemas have been implicated in some instances of dehydration, rectal trauma, water intoxication, and perforation. Careful review of the indications for examination, previous radiographs, and clinical history will identify many of the patients at greater risk for complications so that appropriate precautions may be observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Arrhythmias, Cardiac↗

A longitudinal study of lifestyle factors as predictors of injuries and crashes among young adults.

This study was part of the Dunedin Multidisciplinary Health and Development Study. This is a longitudinal study of the health, development and behaviour of a cohort of 1037 young people born in Dunedin, New Zealand between 1 April 1972 and 31 March 1973. Explanatory measures covering background, behavioural and personality factors were obtained at ages 15 and 18 and were used as potential predictors of outcomes reported at age 21. Four outcomes were considered: any crash, injury crash, non-injury crash, and serious injury (not motor vehicle related). Overall, very few lifestyle factors were important predictors of any of these outcomes. Factors that were shown to predict injury crashes differed from those that predicted non-injury crashes. Also, those that predicted a traffic crash differed from those that predicted a serious non-traffic injury. These results suggest that focusing injury prevention efforts on changing the lifestyles of young adults is unlikely to reduce overall crash risk, and would have little impact on the risk of serious injury.

Accident Prevention↗

Economic effects of childhood cancer on families.

OBJECTIVE: To assess the financial impact of childhood cancer on families. METHODS: This was a cross-sectional survey of parents caring for children who were diagnosed with cancer during the period 1990-1993. Self-administered questionnaires were completed by the parents of 237 children from throughout New Zealand with different types of cancer. Dollar amounts were adjusted to the equivalent of December 2000. RESULTS: Eighty-six per cent of the 192 living children were well or in remission. A further 45 children had died. The average extra amount spent, because of the child's illness, by the family of a living child in the 30 days prior to participation in the study was NZ$220 (SD NZ$330). On average, this was 13% of the family income after tax. After reported entitlement to compensation from various sources was allowed for, families were left with a mean deficit of NZ$157 (SD NZ$278) for the 30 days. Twelve families had a shortfall of more than NZ$500, including three families that had a shortfall of more than NZ$1000. Expenditure was greater for those whose children spent more time in hospital (P = 0.003). There was no significant association between the total cost and the distance travelled to the treatment centre (P = 0.96). For 24 families, after-tax income in the month prior to participation in the study was at least NZ$500 lower than it had been in the month before the child's diagnosis. Thirty-seven per cent of families reported that they needed to borrow money because of the financial effects of the child's illness. Bereaved parents spent an average of NZ$3065 (SD NZ$2168) on funeral expenses. CONCLUSION: There is a large financial burden on families who have a child with cancer.

Adolescent↗

Characterization of the dopaminergic innervation of the primate frontal cortex using a dopamine-specific antibody.

The mesencephalic dopaminergic system has been implicated in the motor and cognitive operations of the cerebral cortex as well as in the pathogenesis of neurological and psychiatric disorders. However, to date, the dopamine (DA)-containing axons of the primate cerebral cortex have not been directly visualized immunohistochemically due to the lack of a DA-specific antibody. We have now analyzed the regional and laminar distribution of DA-immunoreactive (DA-IR) afferents in the frontal cortex of the rhesus monkey using a monoclonal antibody specific for DA. In addition, we compared the distribution of DA-IR processes to tyrosine hydroxylase (the rate-limiting enzyme in DA synthesis) immunoreactive (TH-IR) axons. Frontal cortex displays an elaborate and robust dopaminergic innervation. Although regional differences in the DA-IR innervation were clearly evident, variations in the DA innervation were essentially unrelated to cytoarchitectonic boundaries. Instead, the DA innervation followed two basic gradients: (1) a prominent medial-to-lateral gradient of decreasing fiber density that was most prominent in the dorsal cortical regions, and (2) a more subtle anterior-posterior gradient in which DA-IR fiber density decreased slightly in both rostral and caudal directions from a peak density centered in the region of granular frontal area 8Bm and the supplementary motor area 6M. The laminar pattern of DA-IR axons also showed regional variations that again were typified by smooth transitions irrespective of cytoarchitecture. Analysis of DA-IR axonal morphology indicated that immunoreactive fibers form a basically uniform population, giving little evidence of a bimodal heterogeneity evident in other species.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

MR imaging of a hepatoma associated with Alagille syndrome.

Alagille syndrome is a rare cause of chronic liver failure which may be treated by liver transplantation. When underlying hepatic tumor is present, transplantation has had poor results. Magnetic resonance imaging may be a sensitive, noninvasive method to evaluate the presence of tumor before transplantation.

Abnormalities, Multiple↗

Quantitation of apoptotic bodies in rat liver by in situ end labelling (ISEL): correlation with morphology.

Nongenotoxic hepatocarcinogens have been proposed to inhibit hepatocyte apoptosis, preventing the removal of DNA-damaged cells. Conclusive proof of this hypothesis has been hindered by the lack of a marker or stain for apoptosis suitable for high throughput counting. A method is described for the detection of apoptotic bodies (AB) in paraffin sections of rat liver using an in situ end labeling (ISEL) technique that detects DNA damage. Results of this AB quantitation were compared with routine hematoxylin-eosin (H&E)-stained sections. The number of apoptotic bodies was enhanced by the withdrawal of the rodent nongenotoxic hepatocarcinogens and hepatomitogens nafenopin (naf) or cyproterone acetate (CPA) after 7 days of daily dosing. In rat livers 24-96 hr after cessation of dosing with naf, and in control livers, an AB index of approximately 0.1% of hepatocyte nuclei was seen when stained by H&E or ISEL. However, livers examined 48 hr after cessation of 7 days of daily dosing with CPA had an AB index of approximately 1% hepatocyte nuclei when stained with H&E, but only approximately 0.4% hepatocyte nuclei using the ISEL technique. Thus, CPA withdrawal from the hyperplastic liver generated a wave of apoptosis in contrast to naf withdrawal where little was seen up to 96 hr after withdrawal. The differing kinetics of CPA and naf clearance may explain this discrepancy. Less apoptosis was detected by the ISEL method following CPA withdrawal; this could arise if the stage of apoptosis labeled by ISEL is shorter than the morphologically recognizable stages (using H&E). The ISEL method for the evaluation of AB indices is useful in parallel with H&E, although more validation is required before it can be used routinely for the quantitation of AB in tissue sections.

Animals↗

Psychosocial needs in renal failure: development of a renal support team.

The purpose of this paper is to illustrate how social, emotional and educational support is provided by the Renal Support Team at Dulwich Hospital to clients approaching or already receiving renal replacement therapy. We aim to illustrate how psychosocial needs were met before the creation of the team, how support has developed since this time and how clients are benefiting from this. We will conclude by discussing some future developments within the team.

Counseling↗

Diagnosis of eastern equine encephalitis by immunohistochemistry in two flocks of Michigan ring-neck pheasants.

The diagnosis of eastern equine encephalitis (EEE) virus infection in avian species is relatively difficult when compared with other species. There are no characteristic histologic lesions in the avian brain that would serve to distinguish EEE from infections with, for example, Newcastle disease or highly pathogenic avian influenza virus. Traditionally, virus isolation (VI) and/or hemagglutination inhibition (HI) has been used for a definitive diagnosis of EEE in birds. Recently, we developed an immunohistochemistry (IHC) technique for confirmatory diagnosis of EEE infection in equine brain. This test also detected EEE virus in formalin-fixed avian brain. VI confirmed IHC finding in two cases of EEE in ring-neck pheasants. IHC is a rapid, sensitive test for confirming and differentiating a histopathologic diagnosis of EEE in avian species and should be considered as an alternative test to VI or HI.

Animals↗