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Biomedical subjects

A Paterson

Publications and source records attributed to A Paterson.

At least 19 recordsLinked to original sources
PubMed2005

Large loop excision and cold coagulation for management of cervical intraepithelial neoplasia.

OBJECTIVES: To evaluate the efficacy of large loop excision of the transformation zone (LLETZ) combined with a single application of the cone probe of a Semm Cold Coagulator as a new treatment for women with cervical intraepithelial neoplasia (CIN). METHODS: Retrospective case-record review of 666 women treated with large loop excision and cold coagulation (LLECC) from 1992 to 2000. RESULTS: Of the women who had high-grade CIN at their initial consultation, 4.2% had abnormal cytologic results 6 months after treatment and 0.6% had abnormal cytologic results at 12 months. Of the women who had low-grade CIN at initial presentation, 3.8% had abnormal cytologic results 6 months after treatment and none (0%) at 12 months. Furthermore, there were no reported cases of cervical cancer in this cohort of women during the follow-up period. Short-term bleeding complications (within 24 h of the procedure) occurred in 1% of the women assessed. CONCLUSIONS: Large loop excision combined with cold coagulation is a new and effective treatment for CIN. Randomized controlled trials are required to confirm these findings and determine the long-term safety of the technique.

Adult↗
PubMed2005

Chemometric modeling to relate antioxidants, neutral lipid fatty acids, and flavor components in chicken breasts.

Relationships among quality factors in retailed free-range, corn-fed, organic, and conventional chicken breasts (9) were modeled using chemometric approaches. Use of principal component analysis (PCA) to neutral lipid composition data explained the majority (93%) of variability (variance) in fatty acid contents in 2 significant multivariate factors. PCA explained 88 and 75% variance in 3 factors for, respectively, flame ionization detection (FID) and nitrogen phosphorus (NPD) components in chromatographic flavor data from cooked chicken after simultaneous distillation extraction. Relationships to tissue antioxidant contents were modeled. Partial least square regression (PLS2), interrelating total data matrices, provided no useful models. By using single antioxidants as Y variables in PLS (1), good models (r2 values > 0.9) were obtained for alpha-tocopherol, glutathione, catalase, glutathione peroxidase, and reductase and FID flavor components and among the variables total mono and polyunsaturated fatty acids and subsets of FID, and saturated fatty acid and NPD components. Alpha-tocopherol had a modest (r2 = 0.63) relationship with neutral lipid n-3 fatty acid content. Such factors thus relate to flavor development and quality in chicken breast meat.

Animals↗
PubMed2005

Neck masses in children.

Infants and children with neck masses frequently present to the radiologist for further evaluation. The role of the radiologist is to differentiate between conditions using imaging modalities such as ultrasound with colour Doppler, CT and MRI. Where appropriate, the radiologist will also stage lesions for management purposes and aid in guiding aspiration or biopsy. This paper presents a pictorial review of paediatric neck masses and their imaging features. Particular emphasis is applied to the anatomical site of the mass to aid in differential diagnosis. It must be emphasised that the radiological findings should always be interpreted in conjunction with the patient's age, the clinical history and the findings on physical examination.

Abscess↗
PubMed2005

Forensic facial approximation: an overview of current methods used at the Victorian Institute of Forensic Medicine/Victoria Police Criminal Identification Squad.

Forensic facial approximation involves building a likeness of the head and face on the skull of an unidentified individual, with the aim that public broadcast of the likeness will trigger recognition in those who knew the person in life. This paper presents an overview of the collaborative practice between Ronn Taylor (Forensic Sculptor to the Victorian Institute of Forensic Medicine) and Detective Sergeant Adrian Paterson (Victoria Police Criminal Identification Squad). This collaboration involves clay modelling to determine an approximation of the person's head shape and feature location, with surface texture and more speculative elements being rendered digitally onto an image of the model. The advantages of this approach are that through clay modelling anatomical contouring is present, digital enhancement resolves some of the problems of visual perception of a representation, such as edge and shape determination, and the approximation can be easily modified as and when new information is received.

Aluminum Silicates↗
PubMed2004

Is there value in routinely obtaining a report from the general practitioner as part of pre-entry health screening of students for nursing studies?

BACKGROUND: Reports from general practitioners (GPs) are requested on applicants for nurse training, but there is no published evidence of the merit of this practice. AIMS: To assess the benefit of GP report in health assessments of student nurse applicants. METHODS: An audit was made of information obtained by health declaration form (HDF), nurse's assessment, GP report and, when performed, a physician's assessment for each applicant. Agreement between the health questionnaire and GP report was analysed by kappa statistics. RESULTS: Of 254 applicants, 246 (97%) were declared 'fit to work', four (1.6%) were deemed 'fit with restrictions' and four (1.6%) were considered 'unfit to work'. The most common problems declared were psychiatric and skin problems. The agreement between health declaration and the information provided by GPs was classed as almost perfect for diabetes and only fair to moderate for all other measures. The reports provided additional information on problems not declared by applicants, but all of these were passive problems. The four unfit candidates all had psychiatric illness, but in all cases the occupational health assessment was sufficient to make this decision or to request further information. In the 'fit with restrictions' category, three of the four GP reports (75%) helped in correctly assigning the applicants to this category. In one of these eight cases a passive problem had not been declared. CONCLUSIONS: The additional information in GP reports does not affect the conclusion regarding fitness for training in most cases and does not provide sufficient information to merit it being sought routinely.

Adolescent↗
PubMed2003

An EST survey of the sugarcane transcriptome.

Its large genome and high polyploidy makes sugarcane (Saccharum spp.) a singularly challenging crop to study and improve using genetic approaches. To provide large numbers of functionally characterized candidate genes that might be tested for direct association (rather than distant linkage) with economically important traits, we sequenced the 5' ends of 9,216 clones from three cDNA libraries (apex, leaf and mature internode), representing 3,401 non-redundant sequences. About 57% of these sequences could be assigned a tentative function based on statistically significant similarity to previously characterized proteins or DNA sequences. Another 28% corresponded to previously identified, but uncharacterized, sequences. Some of the remaining unidentified sequences were predicted to be genes which could potentially be new to plants or unique to sugarcane. Comparisons of the sugarcane ESTs to a large sorghum EST database revealed similar compositions of expressed genes between some different tissues. Comparison to a detailed Arabidopsis protein database showed some highly conserved sequences, which might be useful DNA markers for pan-angiosperm comparative mapping. These EST sequences provide a foundation for many new studies to accelerate isolation of agronomically important genes from the cumbersome sugarcane genome.

Base Sequence↗
PubMed2002

Assessment of psychological distress in prospective bone marrow transplant patients.

Patient psychological distress is associated with many aspects of the bone marrow transplantation (BMT) process and has been linked with poor treatment outcomes. We assessed psychological distress in potential BMT candidates, and compared patient and nurse coordinator ratings of emotional distress at the time of initial BMT consultation. Fifty patients self-reported psychological distress using both the NCCN Distress Thermometer (DT) and the Hospital Anxiety and Depression Scale (HADS). Coordinators rated patient emotional distress using the DT and Coordinator Rating Scales that measure anxiety and depression. Fifty and 51% of patients self-reported clinically significant levels of emotional distress and anxiety, respectively, but only 20% self-reported clinically significant levels of depression. There was good correlation between ratings using the brief DT and the more comprehensive HADS. There was significant but only moderate agreement between patient and coordinator ratings of emotional distress and anxiety, with coordinators underestimating the number of patients with high levels of emotional distress. In addition, coordinator ratings of patient emotional distress primarily reflected anxiety, whereas anxiety and depression together only minimally accounted for patient self-reports of psychological distress. These findings suggest that: (1) the DT can be a useful screening device; (2) approximately half of patients at the time of initial consultation for BMT already experience significant levels of psychological distress; and (3) coordinators observe emotional distress primarily as anxiety, but patients experience psychological distress as something more than anxiety and depression.

Adult↗
PubMed2002

Sea level and acute responses to hypoxia: do they predict physiological responses and acute mountain sickness at altitude?

OBJECTIVES: To compare a range of physiological responses to acute sea level hypoxia at simulated altitudes with the same physiological responses and acute mountain sickness (AMS) scores measured at altitude (similar to the simulated altitudes) during a 17 day trek in the Himalayas. METHODS: Twenty men and women aged 18-54 years took part in the study. End tidal CO(2) tension (PETCO(2)) and saturated oxygen (SaO(2)) were measured using a capnograph. Observations made at sea level and some simulated altitudes were compared with those in the Himalayas. Pairwise correlations were used to examine the correlation between variables and regression, with 95% prediction intervals providing information on how well one variable could be predicted from another for a given subject. RESULTS: There was only a significant correlation for a few comparisons. The 95% prediction intervals for individual SaO(2) values at a range of simulated altitudes were fairly wide going from +/- 4% to +/- 5%. All of the correlations between laboratory and Himalayan PETCO(2) values were not statistically significant. There was a significant correlation for the relation between SaO(2)and PETCO(2) at sea level for the laboratory data (r=-0.51; p=0.05). For the Himalayan data, there were significant correlations at Namche Bazaar (3450 m; day 3) (r=-0.56; p=0.01) and Dingboche (4300 m; day 6) (r=-0.48; p=0.03). The correlation between SaO(2) and PETCO(2) and AMS was generally poor. CONCLUSIONS: The results indicate that limited information can be gained on a subject's response to altitude by assessing physiological variables at sea level and a range of simulated altitudes before the subject carries out a trek at altitude.

Adolescent↗
PubMed2001

Phase II study of docetaxel, doxorubicin, and cyclophosphamide as first-line chemotherapy for metastatic breast cancer.

PURPOSE: This pilot phase II study investigated the efficacy and toxicity of docetaxel with doxorubicin and cyclophosphamide (TAC) as first-line chemotherapy for anthracycline-naive patients with metastatic breast cancer. PATIENTS AND METHODS: Fifty-four patients received a total of 359 courses consisting of docetaxel 75 mg/m2 given intravenously (IV) over 1 hour, preceded by IV doxorubicin 50 mg/m2 and cyclophosphamide 500 mg/m2 for a maximum of eight 3-week cycles. RESULTS: After an independent panel review, the overall objective response rate was 77% (complete response, 6%). Overall objective response rates in patients with visceral, bone, and liver involvement were 82%, 82%, and 80%, respectively. Median duration of response was 52 weeks, and median time to progression was 42 weeks. With a median follow-up of 32 months, the median survival had not yet been reached, whereas the 2-year survival was 57%. The main toxicities were hematologic (neutropenia grade 3/4 in 100% of patients and 95% of cycles; febrile neutropenia in 34% of patients and 9% of cycles). Documented grade 3 infection was seen in one patient (2%) in one cycle, and no toxic death was reported. Severe acute or chronic nonhematologic adverse events were infrequent, and docetaxel-specific toxicities (such as fluid retention and nail changes) were mild, with only one patient being discontinued for fluid retention. Congestive heart failure was seen in two patients (4%). CONCLUSION: TAC is an active and manageable regimen that has been chosen as the basis of five randomized phase III trials, including two pivotal studies comparing TAC to fluorouracil plus doxorubicin and cyclophosphamide in the metastatic and adjuvant treatment of breast cancer.

Adult↗
PubMed2001

Lack of consistent behavioural effects of Maudsley reactive and non-reactive rats in a number of animal tests of anxiety and activity.

RATIONALE: A number of previous studies have reported that the Maudsley reactive (MR/Har) and non-reactive (MNRA/Har) strains of rats show behavioural and physiological differences consistent with the hypothesis that these strains differ in emotionality and could therefore be considered a model of trait anxiety in humans. OBJECTIVES: We sought to confirm this observation by determining their behaviour in various animal models of conditioned and unconditioned fear. METHODS: Both strains were evaluated in the open field (OF), conditioned avoidance (CA), elevated plus maze (EPM) and fear-potentiated startle (FPS) tests. In the OF the behaviour of both strains was consistent with previous results showing that reactive rats had significantly higher levels of defecation and lower levels of activity than the non-reactive rats. However, there were no significant strain differences in CA responses or in the time spent on the open arms of the EPM. In addition, the full benzodiazepine receptor agonist, chlordiazepoxide, induced quantitatively similar effects in both strains of rats. In the FPS test, MNRA/Hars had a higher baseline level of startle and fear potentiation than the MR/Har rats. CONCLUSIONS: These data show that the behaviour of MR/Har and MNRA/Har rats in some models of conditioned and unconditioned fear is inconsistent with that predicted by their behaviour in the OF test, suggesting that they are not a model of trait fear.

Animals↗
PubMed2001

Epoetin alfa in cancer patients: evidence-based guidelines.

Anemia is a common cause of cancer-related fatigue. A systematic review of the literature was performed to establish guidelines on the use of epoetin alfa for the treatment of anemia. The evidence in support of these guidelines was selected, reviewed, and summarized by the members of the Canadian Cancer and Anemia Guidelines Development Group. The effects of epoetin alfa on quality of life (QOL) in patients with cancer were examined in 5 randomized, placebo-controlled trials and 2 large, open-label, nonrandomized, community-based studies. The effects of epoetin alfa on red blood cell transfusion requirements were examined in 19 randomized controlled trials (RCTs) with 21 comparisons. All trials compared epoetin alfa to a suitable control group, examined specified outcome measures that could be analyzed, and studied patients with cancer who were receiving chemotherapy. Trials involving patients with hematologic malignancies originating in the bone marrow were excluded. Outcome measures included 1) quality of life (QOL) (as measured by scales including the Linear Analogue Self-Assessment [LASA] and the Functional Assessment of Cancer Therapy [FACT] subscales), and 2) transfusion requirements (as measured by the proportion of patients requiring transfusion and amount of transfusion). The analysis confirmed that epoetin alfa produced statistically significant and clinically relevant improvements in QOL in patients with cancer. The overall relative risk ratio for transfusion among patients receiving epoetin alfa was calculated to be 0.60 (95% Cl, 0.53-0.69; P < 0.00001), representing a 40% reduction in the proportion of patients requiring transfusion. These results support recommendations for the use of epoetin alfa in patients with cancer-related anemia.

Anemia↗
PubMed2001

Peritoneography in the assessment of peritoneal cerebrospinal fluid absorption potential for distal ventriculoperitoneal shunt catheter placement: technical case report.

OBJECTIVE AND IMPORTANCE: Distal ventriculoperitoneal shunt failure has been associated with absorption failure secondary to previous peritonitis. This assumption has caused surgeons to seek alternate sites for distal catheter placement. We propose that the absorptive potential of the peritoneal cavity should be assessed before that site is discounted for catheter placement. CLINICAL PRESENTATION: The case of a 14-month-old male patient is presented, demonstrating multiple ventriculoperitoneal shunt placement procedures and a diagnostic dilemma with respect to distal shunt placement. Peritoneography was performed to demonstrate peritoneal fluid absorption, allowing subsequent placement of a new distal shunt catheter with good clinical results. TECHNIQUE: Using aseptic technique, a 24-gauge spinal needle was inserted in the midline of the abdomen and water-soluble contrast material was instilled. Delayed radiographs delineated peritoneal adhesions and demonstrated renal excretion of the contrast material, confirming peritoneal absorption. CONCLUSION: The peritoneal cavity remains the site of choice for distal shunt catheter placement. If failure of peritoneal cerebrospinal fluid absorption is suspected as a cause of shunt failure, then peritoneography with water-soluble contrast material may be safely used to demonstrate the adequacy of fluid absorption before a secondary site is chosen.

Absorption↗
PubMed2001

Helical CT of the body: are settings adjusted for pediatric patients?

OBJECTIVE: Our objective was to determine whether adjustments related to patient age are made in the scanning parameters that are determinants of radiation dose for helical CT of pediatric patients. SUBJECTS AND METHODS: This prospective investigation included all body (chest and abdomen) helical CT examinations (n = 58) of neonates, infants, and children (n = 32) referred from outside institutions for whom radiologic consultation was requested. Information recorded included tube current, kilovoltage, collimation, and pitch. Examinations were arbitrarily grouped on the basis of the individual's age: group A, 0-4 years; group B, 5-8 years; group C, 9-12 years; and group D, 13-16 years old. RESULTS: Thirty-one percent (18/58) of the CT examinations were of the chest and 69% (40/58) were of the abdomen. Sixteen percent (9/58) of the CT examinations were combined chest and abdomen. In 22% (2/9) of these combined examinations, tube current was adjusted between the chest and abdomen CT; in one (11%) of these examinations, the tube current was higher for the chest than for the abdomen portion of the CT examination. The mean tube current setting for chest was 213 mA and was 206 mA for the abdomen, with no evident adjustment in tube current based on the age of the patient. Fifty-six percent of the examinations of neonates, infants, or children 8 years old or younger were performed at a collimation of greater than 5 mm and 53% of these examinations were performed using a pitch of 1.0. CONCLUSION: Pediatric helical CT parameters are not adjusted on the basis of the examination type or the age of the child. In particular, these results suggest that pediatric patients may be exposed to an unnecessarily high radiation dose during body CT.

Adolescent↗
PubMed2001

Carcinoid syndrome symposium on treatment modalities for gastrointestinal carcinoid tumours: symposium summary.

OBJECTIVE: To develop a collaborative approach for the treatment of gastrointestinal carcinoid tumours and carcinoid syndrome. PARTICIPANTS: Leaders in the medical, endocrine, radiologic and surgical treatment of carcinoid disease were selected to present papers at the Carcinoid Syndrome Symposium on Treatment Modalities for Gastrointestinal Carcinoid Tumours and participate in the workshop that followed. EVIDENCE: A multidisciplinary symposium with experts in the field of carcinoid syndrome was organized at the University of Calgary. Data presented, participation of the attendees and a review of the literature were used in the workshop to develop a collaborative approach to the management of carcinoid tumours. BENEFITS: Carcinoid tumours are rare and few centres have large experiences in their treatment. Before the development of this collaboration, patients with carcinoid tumours received a unidisciplinary approach depending on referral patterns. The development of a multidisciplinary neuroendocrine clinic helped to unify the approach to these patients, yet a consensus on the treatment of carcinoid tumours was lacking. The expertise at the symposium allowed for consensus and the development of treatment algorithms, including biochemical screening, radiographic localization and surgical intervention, for gastrointestinal carcinoid tumours. The role of medical and hormonal therapy after cytoreducion is presented. RECOMMENDATION: Patients with carcinoid tumours require a multidisciplinary approach to their care.

Algorithms↗
PubMed2000

Biologically active recombinant human progastrin(6-80) contains a tightly bound calcium ion.

Evidence is accumulating that gastrin precursors may act as growth factors for the colonic mucosa in vivo. The aims of this study were to prepare recombinant human progastrin(6-80) and to investigate its structure and biological activities in vitro. Human progastrin(6-80) was expressed in Escherichia coli as a glutathione S-transferase fusion protein. After thrombin cleavage progastrin(6-80) was purified by reverse phase high pressure liquid chromatography and characterized by radioimmunoassay, amino acid sequencing, and mass spectrometry. Assays for metal ions by atomic emission spectroscopy revealed the presence of a single tightly bound calcium ion. Progastrin(6-80) at concentrations in the pm to nm range stimulated proliferation of the conditionally transformed mouse colon cell line YAMC. The observations that progastrin(6-80) did not bind to either the cholecystokinin (CCK)-A or the gastrin/CCK-B receptor expressed in COS cells and that antagonists selective for either receptor did not reverse the proliferative effects of progastrin(6-80) suggested that progastrin(6-80) stimulated proliferation independently of either the CCK-A or the gastrin/CCK-B receptor. We conclude that recombinant human progastrin(6-80) is biologically active and contains a single calcium ion. With the exception of the well known zinc-dependent polymerization of insulin and proinsulin, this is the first report of selective, high affinity binding of metal ions to a prohormone.

Amino Acid Sequence↗
PubMed2000

Serine 727 phosphorylation and activation of cytosolic phospholipase A2 by MNK1-related protein kinases.

We have previously reported that in thrombin-stimulated human platelets, cytosolic phospholipase A(2) (cPLA2) is phosphorylated on Ser-505 by p38 protein kinase and on Ser-727 by an unknown kinase. Pharmacological inhibition of p38 leads to inhibition of cPLA2 phosphorylation at both Ser-505 and Ser-727 suggesting that the kinase responsible for phosphorylation on Ser-727 is activated in a p38-dependent pathway. By using Chinese hamster ovary, HeLa, and HEK293 cells stably transfected with wild type and phosphorylation site mutant forms of cPLA2, we show that phosphorylation of cPLA2 at both Ser-505 and Ser-727 and elevation of Ca(2+) leads to its activation in agonist-stimulated cells. The p38-activated protein kinases MNK1, MSK1, and PRAK1 phosphorylate cPLA2 in vitro uniquely on Ser-727 as shown by mass spectrometry. Furthermore, MNK1 and PRAK1, but not MSK1, is present in platelets and undergo modest activation in response to thrombin. Expression of a dominant negative form of MNK1 in HEK293 cells leads to significant inhibition of cPLA2-mediated arachidonate release. The results suggest that MNK1 or a closely related kinase is responsible for in vivo phosphorylation of cPLA2 on Ser-727.

Animals↗
PubMed2000

Synergistic activation of stress-activated protein kinase 1/c-Jun N-terminal kinase (SAPK1/JNK) isoforms by mitogen-activated protein kinase kinase 4 (MKK4) and MKK7.

Stress-activated protein kinase 1 (SAPK1), also called c-Jun N-terminal kinase (JNK), becomes activated in vivo in response to pro-inflammatory cytokines or cellular stresses. Its full activation requires the phosphorylation of a threonine and a tyrosine residue in a Thr-Pro-Tyr motif, which can be catalysed by the protein kinases mitogen-activated protein kinase kinase (MKK)4 and MKK7. Here we report that MKK4 shows a striking preference for the tyrosine residue (Tyr-185), and MKK7 a striking preference for the threonine residue (Thr-183) in three SAPK1/JNK1 isoforms tested (JNK1 alpha 1, JNK2 alpha 2 and JNK3 alpha 1). For this reason, MKK4 and MKK7 together produce a synergistic increase in the activity of each SAPK1/JNK isoform in vitro. The MKK7 beta variant, which is several hundred-fold more efficient in activating all three SAPK1/JNK isoforms than is MKK7 alpha', is equally specific for Thr-183. MKK7 also phosphorylates JNK2 alpha 2 at Thr-404 and Ser-407 in vitro, Ser-407 being phosphorylated much more rapidly than Thr-183 in vitro. Thr-404/Ser-407 are phosphorylated in unstimulated human KB cells and HEK-293 cells, and phosphorylation is increased in response to an osmotic stress (0.5 M sorbitol). However, in contrast with Thr-183 and Tyr-185, the phosphorylation of Thr-404 and Ser-407 is not increased in response to other agonists that activate MKK7 and SAPK1/JNK, suggesting that phosphorylation of these residues is catalysed by another protein kinase, such as CK2, which also phosphorylates Thr-404 and Ser-407 in vitro. MKK3, MKK4 and MKK6 all show a strong preference for phosphorylation of the tyrosine residue of the Thr-Gly-Tyr motifs in their known substrates SAPK2a/p38, SAPK3/p38 gamma and SAPK4/p38 delta. MKK7 also phosphorylates SAPK2a/p38 at a low rate (but not SAPK3/p38 gamma or SAPK4/p38 delta), and phosphorylation occurs exclusively at the tyrosine residue, demonstrating that MKK7 is intrinsically a 'dual-specific' protein kinase.

Animals↗