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Biomedical subjects

C Cooper

Publications and source records attributed to C Cooper.

At least 361 records · Page 20Linked to original sources
PubMed1995

Helical CT of the liver: clinical application of an automated computer technique, SmartPrep, for obtaining images with optimal contrast enhancement.

OBJECTIVES: The purpose of this study was to evaluate an automated computer technique (SmartPrep) for achieving a consistently high level of contrast enhancement in the liver with helical CT. The technique compensates for variability between patients by indicating graphically the time at which scanning should be initiated to reach a desired level of hepatic enhancement. MATERIALS AND METHODS: One hundred nine consecutive patients undergoing helical CT of the abdomen were randomly evaluated, using either a standard 70-sec delay from the start of the injection of contrast material to scanning or a newly developed, commercially available automated technique, SmartPrep. A series of multiple low-dose scans was performed until an arbitrary threshold of hepatic enhancement (50 H) over baseline was achieved. Three regions of interest (ROIs) were imaged on a baseline scan and on contrast-enhanced scans at the upper, mid, and lower liver. Average hepatic enhancement and the standard deviation over baseline was calculated for each group at all anatomic levels. For the SmartPrep group, the range of time between scan initiation and onset of scanning was calculated. RESULTS: The mean hepatic enhancement for the control group (n = 56) was 59.8 +/- 20.1 H, which differed significantly (p = .0002) from that for the SmartPrep group (n = 53), which was 71.6 +/- 15.2 H. Comparison of the variability between the two groups' enhancement levels was also significant (p = .02). The range of delay times for the SmartPrep group was 48-86 sec. In two additional cases, abnormal graphically displayed enhancement curves were the first indication of an improper injection. CONCLUSION: Use of SmartPrep yields a greater and more consistent level of hepatic enhancement from patient to patient than does use of a conventional fixed delay time. The ability to scan more efficiently to achieve greater hepatic enhancement using SmartPrep has significant implications for potential contrast cost savings.

Diagnosis, Computer-Assisted↗
PubMed1995

Pneumatosis intestinalis in adults with AIDS: clinical significance and imaging findings.

OBJECTIVE: The significance of pneumatosis intestinalis in adults with AIDS is unknown. Adults with AIDS are predisposed to pneumatosis intestinalis. The purpose of this study is to determine the clinical significance and to characterize the imaging appearance of this finding in patients with AIDS. MATERIALS AND METHODS: In just over 3 years at our institution, pneumatosis intestinalis in adults with AIDS was detected in six cases. Medical records of those cases were retrospectively analyzed for clinical history, laboratory data, and surgical and pathologic findings. CT scans and abdominal radiographs were analyzed for location and severity of pneumatosis, presence of portal venous gas, pneumoperitoneum, and cystic versus linear gas. RESULTS: Five of the six patients with AIDS-associated pneumatosis intestinalis were managed conservatively or medically without surgical procedures and were discharged from the hospital with resolved or decreasing gastrointestinal complaints. The other patient underwent an exploratory laparotomy because of free intraperitoneal and retroperitoneal air; however, no bowel perforation was found at surgery. CONCLUSION: Pneumatosis intestinalis is a late-stage phenomenon in adult patients with AIDS that characteristically involves the cecum or right colon. Pneumatosis in patients with AIDS may be an indolent abnormality and does not necessarily constitute a surgical emergency or a sign of impending bowel necrosis.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Psychiatric stress debriefing. Alleviating the impact of patient suicide and assault.

Psychiatrists and psychologists have developed the psychological autopsy into a debriefing tool, as well as a learning tool. Use of the CISD has been an effective protocol to help police, fire, ambulance, emergency room, and ICU personnel cope with the effects of violence and trauma. Psychiatric nurses and ancillary personnel also face frequent exposure to violence and trauma. The psychiatric debriefing protocol offers a practical intervention.

Adaptation, Psychological↗
PubMed1995

Patient suicide and assault: their impact on psychiatric hospital staff.

Psychiatric nursing entails its own particular hazards, specifically patient suicide and patient assault on staff. The reactions to these occurrences are manifested in the symptoms of PTSD and grief, which often are exacerbated by administrative reactions and the staff's own countertransference issues.

Awareness↗
PubMed1995

Patterns of joint involvement in osteoarthritis of the hand: the Chingford Study.

OBJECTIVE: The hand is the major site of joint involvement in osteoarthritis (OA), but the clustering of this condition at different joint sites within the hand as part of an entity known as generalized OA remains contentious. We examine this issue in a population sample of 967 peri and postmenopausal women. METHODS: The pattern of radiographic involvement of hand joints was examined using the Kellgren and Lawrence system in a sample of women aged 45-64 years, selected from the general population in Chingford, East London. Log linear modelling techniques were used to examine clustering of OA in different joint sites and to examine whether this clustering remained significant after age adjustment. RESULTS: There was clear evidence of clustering in joint involvement: Thus 20 women had 4 or more affected joints compared with only 2 expected (chi 2 = 72.0, 4df, p < 0.001). The risk of multiple distal interphalangeal (DIP) joint involvement, after age adjustment, in a woman with a single affected DIP joint was significantly increased (OR 10.0, 95% CI 7.3-13.7) and was substantially greater than the corresponding risk for proximal interphalangeal joint (OR 3.1, 95% CI 1.4-6.8) involvement. Symmetry was the strongest determinant of pattern with an OR 38.8 (95% CI 14.5-103.5) for corresponding DIP joint involvement in the contralateral hand. CONCLUSION: These data provide clear evidence for a polyarticular subset of hand OA in women. There are 3 major determinants of the pattern of polyarticular involvement; symmetry, clustering by row and clustering by ray, in descending order of importance.

Female↗
PubMed1995

Contrasts between metropolitan and rural general practice in the delivery of after-hours care.

OBJECTIVE: To describe: 1. current arrangements for the delivery of after-hours primary care in general practice. 2. GPs' satisfaction with these arrangements, and 3. the perceived barriers to improving after-hours care in general practice. DESIGN: Telephone survey of a random sample of general practitioners using a standardised questionnaire. SETTING: Two general practice populations, one urban (Central Sydney Division), and one rural (Central Western Division). RESULTS: The response rate was 71%. Almost all rural GPs (95%) provided after-hours care whereas 50% of urban practices provided after-hours care for their patients. Rural GPs expressed a significantly higher degree of satisfaction with their after-hours care arrangements. Half of the GPs providing all their after-hours care reported that they would be prepared to enter into co-operative arrangements with other practices. Thirty-seven per cent of urban GPs who did not provide all their after-hours care indicated that they would be prepared to enter into co-operative arrangements with other practices. CONCLUSIONS: Many of the barriers to providing effective after-hours care may be overcome by establishing after-hours co-operatives.

Adult↗
PubMed1995

Helical (spiral) computed tomography. Implications for imaging of the abdomen.

Dramatic refinements in CT technology are resulting in improved evaluation of the liver, pancreas, and gastrointestinal tract. Further clinical trials are necessary to compare the relative merits of CT versus MR imaging and endoscopic ultrasonography in a wide variety of gastrointestinal diseases.

Gastrointestinal Diseases↗
PubMed1995

Detection of Toxoplasma gondii-specific IgA in the serum of cats.

An ELISA for detection of Toxoplasma gondii-specific IgA in feline serum was developed. A group of cats (n = 7) was inoculated orally with T gondii bradyzoites. Toxoplasma gondii-specific serum IgM, IgG, and IgA responses were followed sequentially by use of the ELISA for 34 weeks. Serum IgA was detected later than IgM or IgG, and was detected in most cats on week 34 after inoculation. None of the cats was seropositive for IgA during the oocyst-shedding period. A group of client-owned cats with suspected clinical toxoplasmosis and a group of healthy cats were tested for T gondii-specific IgA in serum. A trend toward association of T gondii-specific IgA in serum of cats with ocular disease was observed.

Animals↗
PubMed1995

Helical (spiral) CT of the pancreas and biliary tract.

Helical scanning offers many advantages for the evaluation of benign and malignant pancreatobiliary disease. This article presents these advantages, recommended screening protocols, and guidelines for the use of three-dimensional rendering of the peripancreatic vessels and bile ducts.

Biliary Tract Diseases↗
PubMed1995

Occupational activity and the risk of osteoarthritis.

Osteoarthritis (OA) is now recognized as a major public health problem. The risk of OA depends upon factors that increase generalized susceptibility to the disorder, as well as biomechanical factors that modify risk at specific joint sites. Occupational physical activity is one of the important influences in this latter category. Epidemiological evidence has begun to mount that occupational physical activity is a determinant of the risk of knee and hip OA. Occupations that involve regular knee bending and heavy lifting confer a greater likelihood of developing knee OA, while there appears to be a particular propensity for hip OA among farmers. Further research into these relationships will have two important consequences: (1) The issue whether industrial recompense is justified for workers in these industries who develop OA will be clarified. (2) A clearer understanding of the pathophysiology of these relationships will lead to more effective preventive strategies.

Biomechanical Phenomena↗
PubMed1994

Increased apoptosis in the cingulate sulcus of newborn piglets following transient hypoxia-ischaemia is related to the degree of high energy phosphate depletion during the insult.

An increase in the number of cells undergoing apoptosis was observed in the cingulate sulcus of newborn piglets 48 h after a global hypoxic-ischaemic insult. Apoptotic death was identified morphologically (by light and electron microscopy) and by DNA fragmentation, detected by in situ end labelling. The number of apoptotic cells was directly related to the degree of high-energy phosphate depletion during hypoxia-ischaemia, measured using continuous 31P magnetic resonance spectroscopy. These results may have implications for the understanding and treatment of perinatal hypoxic-ischaemic brain injury.

Animals↗
PubMed1994

Structure and polymorphism of the mouse prion protein gene.

Missense mutations in the prion protein (PrP) gene, overexpression of the cellular isoform of PrP (PrPC), and infection with prions containing the scrapie isoform of PrP (PrPSc) all cause neurodegenerative disease. To understand better the physiology and expression of PrPC, we retrieved mouse PrP gene (Prn-p) yeast artificial chromosome (YAC), cosmid, phage, and cDNA clones. Physical mapping positions Prn-p approximately 300 kb from ecotropic virus integration site number 4 (Evi-4), compatible with failure to detect recombination between Prn-p and Evi-4 in genetic crosses. The Prn-pa allele encompasses three exons, with exons 1 and 2 encoding the mRNA 5' untranslated region. Exon 2 has no equivalent in the Syrian hamster and human PrP genes. The Prn-pb gene shares this intron/exon structure but harbors an approximately 6-kb deletion within intron 2. While the Prn-pb open reading frame encodes two amino acid substitutions linked to prolonged scrapie incubation periods, a deletion of intron 2 sequences also characterizes inbred strains such as RIII/S and MOLF/Ei with shorter incubation periods, making a relationship between intron 2 size and scrapie pathogenesis unlikely. The promoter regions of a and b Prn-p alleles include consensus Sp1 and AP-1 sites, as well as other conserved motifs which may represent binding sites for as yet unidentified transcription factors.

Animals↗
PubMed1994

Are hip fractures caused by falling and breaking or breaking and falling? Photoelastic stress analysis.

The distribution of stress in the heads of femurs has been assessed using an engineering technique known as photoelastic stress analysis. The aim of the investigation was to locate and evaluate the probable sites of structure failure in femurs with various axes of loading. The analysis shows that the maximum stress in the upper femur occurs in the cervical region during vertical loading. Lateral loading does not produce significant stress patterns at the sites of extracapsular hip fracture. It is concluded that cervical hip fractures in individuals suffering from osteoporosis result from a combination of fatigue damage and axial muscular compression, rather than forces generated by a fall. This has significance for the medico-legal interpretation of the cause of death following femoral neck fracture.

Accidental Falls↗