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Biomedical subjects

J Davidson

Publications and source records attributed to J Davidson.

At least 37 records · Page 2Linked to original sources
PubMed2001

Positron emission tomography of the thyroid, with an emphasis on thyroid cancer.

The role of Positron Emission Tomography (PET) using 18F-fluorodeoxyglucose (FDG) in the management of thyroid cancer is discussed. It is important to ensure that patients are relaxed because uptake of FDG in tense or active muscles in the neck and larynx can be misinterpreted as metastases. The major role for PET is in patients where the stage of disease is uncertain, usually the result of discordant negative 131I scan and a positive serum thyroglobulin (Tg) values. PET identifies the source of Tg production in 50-80% of patients. PET scan can be negative in well differentiated cancers which retain the ability to trap iodine. This can result in a 'flip/flop', with negative PET, positive radio-iodine scan, or positive PET, negative radioiodine scan. PET is also valuable in identifying the source of calcitonin production in patients with medullary thyroid cancer. When focal uptake is seen in the thyroid of patients who are scanned for non thyroidal reasons, the likelihood of primary thyroid cancer is high. In contrast diffuse uptake of FDG in the thyroid is usually the result of auto-immune thyroid disorders.

Diagnosis, Differential↗
PubMed2001

Management and survival of patients with lung cancer in Scotland diagnosed in 1995: results of a national population based study.

BACKGROUND: The prognosis of patients with lung cancer in Scotland is poor and not improving. This study was designed to document factors influencing referral, diagnostic evaluation, treatment, and survival in patients with lung cancer. METHODS: Patients diagnosed during 1995 were identified from the Scottish Cancer Registry and their medical records were reviewed. Adequate records were available in 91.2% of all potentially eligible cases. RESULTS: In 1995, patients in Scotland with lung cancer had a high rate of microscopic verification (74.1%) and 75.3% were assessed by a respiratory physician; however, only 56.8% received active treatment (resection 10.7%, radiotherapy 35.8%, chemotherapy 16.1%) and 2.9% participated in a clinical trial. Survival was poor with a median of 3.6 months; 21.1% (95% CI 19.8% to 22.4%) were alive at 1 year and 7.0% (95% CI 6.2% to 7.8%) at 3 years. Management by respiratory physician, oncologist, or thoracic surgeon was an independent predictor of access to potentially curative treatment and better survival. CONCLUSION: This national population based study demonstrates low use of treatment, poor survival, and the influence of process of care on survival. Implementation of evidence-based guidelines will require substantial changes in practice. Increasing the number of patients who receive treatment may improve survival.

Adult↗
PubMed2001

Efficacy of sertraline in preventing relapse of posttraumatic stress disorder: results of a 28-week double-blind, placebo-controlled study.

OBJECTIVE: The study examined the efficacy of sertraline, compared with placebo, in sustaining improvement and preventing relapse over 28 weeks in patients with posttraumatic stress disorder (PTSD) who had completed a 12-week double-blind, placebo-controlled acute treatment study and a subsequent 24-week open-label study of continuation treatment with sertraline. METHOD: Ninety-six patients were randomly assigned, in a double-blind design, to 28 weeks of maintenance treatment with sertraline (50-200 mg, N=46; 78% were women) or placebo (N=50; 62% were women). Measures used in biweekly assessments included the Clinician-Administered PTSD Scale, the Impact of Event Scale, and the Clinical Global Impression severity and improvement ratings. Kaplan-Meier analyses were used to estimate time to discontinuation from the study due to relapse, relapse or study discontinuation due to clinical deterioration, and acute exacerbation. RESULTS: Continued treatment with sertraline yielded lower PTSD relapse rates than placebo (5% versus 26%). Patients who received placebo were 6.4 times as likely to experience relapse as were patients who received sertraline. Kaplan-Meier analyses confirmed the protective effect of sertraline in significantly extending time in remission. The ability of sertraline to sustain improvement was comparable across the three core PTSD symptom clusters (reexperiencing/intrusion, avoidance/numbing, and hyperarousal). A regression analysis found early response during acute treatment to be associated with a more than 16-fold reduced risk of relapse after placebo substitution. Sertraline, at a mean endpoint dose of 137 mg, was well tolerated, with no sertraline-related adverse events observed at a rate of 10% or higher. CONCLUSIONS: The results provide evidence for the ability of sertraline both to sustain improvement in PTSD symptoms and to provide prophylactic protection against relapse.

Adult↗
PubMed2001

Picking peers.

Explore the source record for details and available documents.

Career Mobility↗
PubMed2000

Amplification of immunological functions by subcutaneous injection of intermediate-high dose interleukin-2 for 2 years after autologous stem cell transplantation in children with stage IV neuroblastoma.

BACKGROUND: Immunotherapy given post-autologous stem cell transplantation may eliminate residual tumor cells escaping the conditioning protocol. METHODS: Five children suffering from stage IV neuroblastoma were treated by recombinant interleukin-2 (IL-2) post-autologous peripheral blood stem cell transplantation. The patients' peripheral mononuclear cells were monitored for CD3+ and CD56+ levels, their proliferative response and killing of various cell lines targets. RESULTS: An increase in the level of total lymphocytes, mainly due to expansion of T cells, and enhanced proliferative response to phytohemaglutinin were observed. Elevated cytotoxicity against K562 and neuroblastoma target cells was detected in four patients and against K562 targets in one patient. Toxicity included mild thrombocytopenia, and fever in four patients and mild to moderate encephalopathy which necessitated withdrawing one patient from the protocol. Three of five patients studied are alive today, one of them whose IL-2 was stopped, is in relapse. Two patients have died. CONCLUSIONS: Immunotherapy with s.c. intermediate-high dose IL-2 is feasible and results in expansion of T cells and in stimulation of killing activity against several targets including in some cases, neuroblastoma tumor cells.

Child, Preschool↗
PubMed2000

Comparing treatment outcomes of radiotherapy and surgery in locally advanced carcinoma of the larynx: a comparison limited to patients eligible for surgery.

PURPOSE: The use of radical radiotherapy and surgery for salvage (RRSS) in locally advanced squamous cell carcinoma (SCC) of the larynx is controversial. In the absence of randomized studies, it is unclear if RRSS can match the rates of locoregional control and survival reported for primary surgery in this setting. The aim of this study was to compare treatment outcomes of radiotherapy and surgery in comparable patients with CS III-IV SCC of the larynx. METHODS AND MATERIALS: Eighty-two patients with untreated T2N+M0 or T3T4NM0 SCC of the larynx were treated with a policy RRSS at the Toronto-Sunnybrook Regional Cancer Centre between June 1980 and December 1990. The medical records at presentation were reviewed independently by a panel of three surgical oncologists blinded as to treatment outcome to determine patient suitability for laryngectomy and neck dissection using eligibility criteria adopted by recent clinical trials. Treatment outcomes for surgery-eligible patients were compared to results of comparably staged patients in the surgical literature since 1980. RESULTS: Sixty-three patients (77%) were eligible for study. With a median follow-up of 3 years, radiotherapy controlled the primary in 8/20 evaluable glottic primaries and 21/41 evaluable supraglottic primaries. Forty-five percent of patients surviving 5 years retained a functional larynx. Sixteen of 29 relapsing patients were salvaged with surgery. Disease above the clavicles was controlled in 65% of T3T4N0N+ glottic primaries (compared to a published range of 53% to 79%) and 82% of T3N0 glottic primaries (compared to a published range of 69% to 84%). The 5-year overall survival of patients with T3T4 glottic cancer was 54% compared to a published range of 50% to 63%. The cause-specific survival (CSS) of patients with T3N0 glottic primaries (86% at 1 year and 73% at 2 years) was identical to the only published report of CSS in the surgical literature. CONCLUSION: A policy of RRSS offers a good chance of laryngeal conservation without compromising ultimate locoregional control or survival when compared to primary laryngectomy and neck dissection in patients with locally advanced carcinoma of the larynx meeting the surgical eligibility of clinical trials.

Aged↗
PubMed2000

The role of panendoscopy in the management of mucosal head and neck malignancy-a prospective evaluation.

BACKGROUND: It is common practice for a panendoscopy to be included in the evaluation of patients with mucosal head and neck malignancies. Whether this intervention is efficient or cost-effective has not been established in our patient population. METHODS: Two hundred twenty-four patients with squamous cell carcinoma involving the oral cavity, pharynx, larynx, or neck were evaluated prospectively with panendoscopy and chest x-ray with or without barium swallow. One hundred fifty-four patients had newly diagnosed tumors and 70 were previously diagnosed and currently undergoing symptom-directed investigations. RESULTS: The incidence of synchronous primary tumors was 2.6% (4 of 154); pulmonary, 1.3%; head and neck mucosa, 1.3%; and esophageal, 0%. There was no associated morbidity. CONCLUSIONS: Although there was no associated morbidity, our head and neck oncology group is of the opinion that routine panendoscopy is not warranted. Specific indications for this investigation are discussed.

Barium Sulfate↗
PubMed2000

How frequently is the thymus seen on whole-body iodine-131 diagnostic and post-treatment scans?

The purpose of the study was to determine how often the thymus is visualized on whole-body radioiodine scans. One hundred and seventy-five patients had 325 diagnostic scans and 200 post-treatment scans. Activity in the mediastinum possibly consistent with the thymus was seen on seven scans in six patients. Four of these were diagnostic scans (three were second follow-up scans, and the fourth, a third follow-up scan). Three post-treatment scans demonstrated mediastinal uptake. Only one patient had persistent mediastinal uptake on both a post-treatment scan and a subsequent follow-up diagnostic scan. None of these six patients were treated as a result of this finding and none has clinical or biochemical evidence of metastatic disease.

Adolescent↗
PubMed2000

Pethidine-augmented white cell scintigraphy in inflammatory bowel disease.

Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) white cell scintigraphy is invaluable for assessing the presence and extent of disease activity in patients with inflammatory bowel disease. Interpretation of images can be compromised by physiological excretion of tracer into the bowel via the biliary tree. This study assesses the effect of intravenous pethidine administered with the labelled white cells in an attempt to reduce the enterohepatic circulation of the tracer. Ninety-one subjects with proven or suspected inflammatory bowel disease were included in this study, all of whom underwent 99mTc-HMPAO white cell scintigraphy. The control group of 50 subjects underwent the standard protocol for this study performed in our department. The other 41 subjects received an intravenous injection of 0.3 mg/kg of pethidine at the same time as re-injection of the labelled white cells. Images were graded using a five-point scale at both 1 and 2.5 h and categorised as positive, negative or non-diagnostic. Each scan was also assessed for the presence of a visible gall-bladder. The pethidine group had significantly fewer non-diagnostic scans than the control group (P=0.003), and significantly (P=0.001) more studies in which the gall-bladder was visualised. It is concluded that the use of pethidine appears to reduce biliary excretion of tracer during 99mTc-HMPAO white cell scintigraphy. This may allow the delayed images, and early images with low-grade tracer uptake in the bowel, to be interpreted with greater confidence and thereby reduce the number of scans classified as non-diagnostic.

Adolescent↗
PubMed2000

Juvenile idiopathic arthritis: a clinical overview.

The chronic arthritides in childhood remain a poorly understood group of conditions. Their classification has been a source of much confusion over the years with differences in terminology between Europe and North America. A significant step forward in paediatric rheumatology has been the recent development of an internationally agreed classification system which uses the overall term juvenile idiopathic arthritis (JIA). The various subtypes of JIA and their clinical features are described, together with an overview of their differential diagnosis, complications and outcomes. An outline of current management strategies is given and potential future developments highlighted.

Arthritis, Juvenile↗
PubMed2000

Dermatomyositis and Whipple's disease.

A 14-year-old boy presented with a 3-year history of a skin rash typical of juvenile dermatomyositis, and a 2-month history of mild proximal weakness, myalgia, and weight loss. A quadriceps biopsy showed perifascicular fibre atrophy, focal necrosis and regeneration, immunohistochemical labelling for HLA-1 on the surface of the fibres, and focal C5-9 deposition in capillaries. Macrophages with diastase-resistant, PAS-positive cytoplasm were present. Ultrastructural studies showed electron dense and membranous debris. The patient's symptoms responded to intravenous immunoglobulin and oral prednisolone. Four months after discontinuing prednisolone, the patient developed cardiac failure, ventricular tachycardia, and a recurrence of his rash. The 16S ribosomal RNA specific for Tropheryma whippelii was identified by polymerase chain reaction (PCR) analysis in skeletal and cardiac muscle. The myalgia and skin rash responded to prednisolone and oral co-trimoxazole, and the tachycardia is controlled by oral verapamil. This patient appears to have a novel association of juvenile dermatomyositis and Whipple's disease.

Actinobacteria↗
PubMed2000

Cytochrome oxidase deficiency presenting as birth asphyxia.

Hypoxic-ischaemic encephalopathy (HIE) was diagnosed in an infant with acidosis. At 7 weeks of age further investigations revealed abnormal neuroimaging (CT and MRI scans) and a raised plasma and CSF lactate. A skeletal-muscle biopsy at 2 months of age confirmed the diagnosis of cytochrome oxidase deficiency. The course of the patient's disorder has taken that of a static encephalopathy (cerebral palsy). Inborn disorders of the respiratory chain should be considered in the differential diagnosis of HIE.

Acidosis, Lactic↗
PubMed2000

A single intrapleural injection of transforming growth factor-beta(2) produces an excellent pleurodesis in rabbits.

The purpose of the present study was to determine whether the intrapleural injection of transforming growth factor beta(2) (TGF-beta(2)) would produce a pleurodesis in rabbits. Single intrapleural injections of TGF-beta(2) at doses of 5.00 microg (n = 12), 1.67 microg (n = 10), 0.50 microg (n = 10), or 0.167 microg (n = 4), or of the parenteral buffer alone (n = 5) were given in a volume of 2 ml to New Zealand white rabbits. Chest tubes were left in place for at least 72 h. Pleural fluid was aspirated at 24-h intervals and was measured and subjected to chemical analysis. The animals were killed 14 d after the injection. The intrapleural injection of TGF-beta(2) resulted in a dose-dependent pleurodesis (on a scale of 0 to 4, where 0 = no pleurodesis and 4 = complete pleurodesis) with mean scores of 3.6, 2.6, 1.5, 0.7, and 0.3 for the groups that received 5.0, 1.67, 0.50, and 0.167 microg of TGF-beta(2) and buffer alone, respectively. Intrapleural injection of the larger doses of TGF-beta(2) resulted in the formation of a large amount of pleural fluid. The fluid had a significantly lower white blood cell (WBC) count and lactate dehydrogenase (LDH) level than did the fluid that results from the intrapleural injection of 10 mg/kg doxycycline or 400 mg/kg talc slurry. On the basis of this study we conclude that a single intrapleural injection of TGF-beta(2) induces pleurodesis in a dose-dependent manner. A dose of 5.0 microg produced satisfactory pleurodesis in almost all of the rabbits so treated. Larger doses of TGF-beta(2) induced larger pleural effusions with relatively low pleural fluid WBC counts and LDH levels. The ability of TGF-beta to produce a pleurodesis in patients with recurrent pleural effusions or pneumothorax should be investigated. A single intrapleural injection of TGF-beta(2) may produce a pleurodesis both safely and painlessly.

Animals↗
PubMed2000

Partial hepatectomy and laparoscopic-guided liver biopsy in rhesus macaques (Macaca mulatta): novel approach for study of liver regeneration.

BACKGROUND AND PURPOSE: Although valuable information has been gained using a rodent partial hepatectomy model to assess liver regeneration, the ability to apply this research to humans remains uncertain. Thus, liver regeneration was assessed in a non-human primate, the rhesus macaque (Macaca mulatta). METHODS: One animal underwent 60% hepatectomy, a second animal underwent 30% hepatectomy, and control surgery (cholecystectomy) was performed on two separate animals. Laparoscopic-guided liver biopsy was performed on days 1, 2, 7, 14, and 30 after surgery. Changes in hemoglobin concentration and alanine transaminase activity were assessed, and liver regeneration was evaluated by measuring the expression of Ki-67. RESULTS: All animals survived surgery and laparoscopy. Substantial liver regeneration was induced in the animal that underwent 60% hepatectomy. Excellent tissue specimens were obtained via laparoscopic-assisted liver biopsy. CONCLUSIONS: Sixty percent partial hepatectomy in rhesus macaques appears to be an excellent model for the study of hepatocellular regeneration. The procedure was safe, and effectively induced liver regeneration. In addition, laparoscopic-guided liver biopsy allows observation of changes in the liver remnant as regeneration develops, and provides excellent tissue specimens for analysis. Thus, this rhesus macaque partial hepatectomy model will allow further characterization of liver regeneration in a species closer to humans.

Animals↗
PubMed2000

Golden slumbers.

It is interesting to listen to theatre staff who have experienced surgery themselves. Sometimes they have totally changed their practice as a result of their experience, or at any rate have adjusted it. Jeannette has chosen on this occasion to share her distinctive patient's eye view of her trip behind the doors and to pass on her views on anaesthetics. Of course, Jeannette does it all in her own inimitable style, and other patients will not formulate their thoughts in quite the same fashion, nor deliver the message so amusingly ... but how often do we ask the patients for their views? Read the message and sing out....

Attitude of Health Personnel↗