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Biomedical subjects

D Rose

Publications and source records attributed to D Rose.

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

Synovial chondromatosis of the elbow.

Synovial chondromatosis is an uncommon disorder with rare occurrence in the elbow. Case reports in the literature for elbow synovial chondromatosis have described presenting symptoms secondary to peripheral nerve compressions or localized bursitis. We discuss a case of synovial chondromatosis of the elbow that presented as an isolated soft-tissue mass over the radial head-more suggestive of a soft-tissue tumor than of synovial chondromatosis.

Chondromatosis, Synovial↗
PubMed2001

Informed consent for people with diminished capacity to consent.

This paper discusses the rights and responsibilities of patients and providers in New Zealand when a patient has diminished capacity to understand and provide consent for dental care. The Code of Health and Disability Services Consumers' Rights 1996, the Protection of Personal and Property Rights Act 1988, and the New Zealand Bill of Rights Act 1990 all affect decisions that relate to the provision of dental care for patients with diminished capacity to consent. A person's capacity to understand medical or dental procedures will vary with differing procedures and may vary at different points in time. Capacity to consent must be assessed by the dentist responsible for the proposed dental care in the first instance. Welfare guardians and power of attorney may exist for some patients with diminished capacity to consent, but the documentation of appointment to those roles should be read by the dentist to verify the extent of the appointment. When a patient is not competent to make an informed choice and give informed consent, treatment providers may provide care under Right 7.4 of the Code of Health and Disability Services Consumers' Rights 1996 if the appropriate provisions within the Code are satisfied.

Decision Making↗
PubMed2000

Intensified physiotherapy improves fitness to fly in cystic fibrosis patients.

OBJECTIVES: The life expectancy for patients with cystic fibrosis has risen constantly within the last 10 years to an average age over 20 years in western countries. However, most of these patients are partially respiratory insufficient. Frequently their physicians must decide whether it is acceptable to expose them to reduced air pressure on board of an aeroplane during long distance flights or how their fitness to fly can be improved prior to their annual vacation. We investigated the effect of intensified daily physiotherapy -carried out during a four weeks stay on Gran Canaria, Spain- on lung-function parameters, oxygen saturation and saliva neopterin as marker for ongoing inflammation in the respiratory tract. METHODS: 10 out of 12 patients (age 19 34 years, mean 28.6 years) were investigated two weeks prior and two weeks after their trip to the Canaries, Spain. Lung function on ground level and during flights to and from the island, oxygen saturation and saliva-flow adjusted neopterin in saliva were measured. RESULTS: Over the entire group vital capacity (VC) improved significantly from 2.89 l (range 1.37 3.95) to 3.36 l (range 1.23 5.24). Intrathoracic gas volume as a sign for pulmonary hyperinflation- declined slightly from 3.79 l (range 2.06 6.17) to 3.48 l (range 2. 18 5.85). The oxygen saturation increased from 89.5% (range 79 - 92%) during the flight to the Canaries to 94% (range 82 - 96%) during the return flight. Saliva neopterin dropped from 0.8 pmol/min. (range 0.2 6.8 pmol/min) to 0.6 ( range 0.1 2.6 pmol/min) pointing to diminished inflammation in the respiratory tract. CONCLUSION: Our results indicate that fitness to fly can be improved by intense physiotherapy as shown by improvement of vital capacity and oxygen saturation during flight. The influence of an additional climate change on the improvement of lung function in CF-patients needs further evaluation.

Adaptation, Physiological↗
PubMed2000

Acute exposure to the abused inhalant, isobutyl nitrite, reduced T cell responsiveness and spleen cellularity.

Isobutyl nitrite is an inhalant abused principally by male homosexuals. We have reported that subchronic inhalation exposure (45 min/day for 14 days) to 900 ppm isobutyl nitrite was immunosuppressive. In the present study, the effects of acute exposure to the inhalant were examined. Mice were exposed in an inhalation chamber to 900 ppm isobutyl nitrite for 45 min. One day later, spleen cellularity was reduced by 39% without selectively depleting CD4(+) or CD8(+) cells. The numbers of peripheral blood leukocytes and peritoneal cells were also reduced. Following acute inhalation exposure, T cell proliferative responses stimulated with allogeneic cells or anti-CD3 and anti-CD28 antibodies were inhibited, while mitogen-induced responses were not affected. Purified T cells exposed to the inhalant also had compromised responses, suggesting a direct effect on T cells. However, the cumulative effects of multiple exposures were necessary to inhibit T-dependent antibody responses or T cell or macrophage cytotoxicity.

Administration, Inhalation↗
PubMed2000

Synaptic target recognition at Drosophila neuromuscular junctions.

Every synaptogenesis begins with "synaptic target recognition," a cell-cell recognition event in which a neuron and its target stably adhere. Despite its importance in developing nervous systems, synaptic target recognition has been difficult to study in complex systems. The relatively simple and genetically accessible Drosophila NMJ model system provides a repertoire of target recognition cues. We describe how these molecules control the targeting of specific growth cones in either a positive (synaptogenic) or negative (anti-synaptogenic) manner. We also propose two alternate signaling paradigms to explain how these initial cell recognition events are coupled to the intracellular signaling pathways that begin the process of synapse maturation.

Animals↗
PubMed2000

Cytology of thymomas: emphasis on morphology and correlation with histologic subtypes.

BACKGROUND: Aspirates of thymomas are distinguishable from other lesions and fine-needle aspiration (FNA) is a proven method for investigating mediastinal masses. METHODS: Thirty-four cytology specimens of thymomas from 31 patients were examined. Corresponding surgical materials were available in 32 cases. Ten cases were benign and 22 were malignant. Cytologic features of these thymomas were correlated with various histologic classification systems and with biologic behavior. Dual epithelial and lymphoid populations and irregular cohesive tissue fragments of varying proportions of lymphoid and epithelial cells were characteristic of all aspirates. RESULTS: Using the Lattes-Bernatz classification, 10 cases predominately were lymphocytic, 3 cases predominately were epithelial, 3 cases predominately were spindle, 15 cases predominately were mixed, and 1 case was a thymic carcinoma. In the Muller-Hermelink classification, 3 cases were medullary, 12 were mixed, 8 predominately were cortical, 2 were cortical, 6 were well differentiated thymic carcinoma, and 1 was a poorly differentiated thymic carcinoma. In the majority of the cases the epithelial cells were round to oval. Spindle cells and a mixture of round to oval and spindle cells also were observed. No cytologic feature was found to correlate significantly with any classification scheme. Necrosis was present in 5 of the 32 aspirates, most frequently in malignant tumors. Thymomas showing predominately spindle cells frequently were encapsulated. Tumors with predominantly round to oval cells or a mixed population behaved more aggressively than those with spindle cells. Tumors that were well encapsulated and benign clinically tended to possess benign-appearing nuclei. Among the 22 invasive or malignant lesions, 8 exhibited moderate to marked cytologic atypia and 14 showed little or no atypia. No atypia was observed in benign tumors. CONCLUSIONS: The presence of cytologic atypia of epithelial cells may be helpful in predicting aggressiveness. However, the absence of atypia and necrosis may not imply a benign course. Correlation with clinical and radiographic findings should be sought.

Adult↗
PubMed2000

The ultrastructural interactions of identified pre- and postsynaptic cells during synaptic target recognition in Drosophila embryos.

During the development of neural networks, what sets synaptogenic interactions apart from nonsynaptogenic interactions is not well understood at the subcellular level. Using a combination of intracellular dye injection and electron microscopy, we show that a specific motoneuron (RP3) and its synaptic partners (muscles 6 and 7), both often bearing microprocesses, develop intimate membrane contact sites characterized by junctional structures, prior to their initiating synaptogenesis in Drosophila embryos. Other motoneuron growth cones that extend alongside the RP3 growth cone to innervate surrounding muscles do not form such contacts with muscles 6 and 7. We also examined how specific target recognition molecules affect the development of these ultrastructural associations between synaptic partner cells. When Fasciclin III (Fas3), a "positive" target recognition molecule for RP3, is ectopically expressed in neighboring muscles, the RP3 growth cone ectopically develops membrane contact sites with Fas3-misexpressing muscles with which it would not normally associate. In contrast, when Toll, a "negative" target recognition molecule normally expressed by a subset of muscles that surrounds muscles 6 and 7, is misexpressed on muscles 6 and 7, the RP3 growth cone fails to exhibit its normal close contact with these muscles. We propose that the formation of close membrane associations and junctional structures can be regulated under the influence of synaptic target recognition molecules and signifies the beginning of subcellular events during synaptic target recognition.

Animals↗
PubMed2000

Social class differences in mortality using the National Statistics Socio-economic Classification--too little, too soon: a reply to Chandola.

Chandola's (2000; Social Science and Medicine, 50(5), 641-649) claims that the UK National Statistics Socio-economic Classification (NS-SEC) is not significantly related to mortality are examined. It is shown that this result is likely to be an artefact of the data and methods he uses. Other findings and interpretations in his paper are also critically discussed. In the process, various theoretical, measurement and analysis issues relating to the use of classifications such as the NS-SEC in health research are reviewed.

Humans↗
PubMed2000

Respiration of arsenate and selenate by hyperthermophilic archaea.

A novel, strictly anaerobic, hyperthermophilic, facultative organotrophic archaeon was isolated from a hot spring at Pisciarelli Solfatara, Naples, Italy. The rod-shaped cells grew chemolithoautotrophically with carbon dioxide as carbon source, hydrogen as electron donor and arsenate, thiosulfate or elemental sulfur as electron acceptor. H2S was formed from sulfur or thiosulfate, arsenite from arsenate. Organotrophically, the new isolate grew optimally in the presence of an inorganic electron acceptor like sulfur, selenate or arsenate. Cultures, grown on arsenate and thiosulfate or arsenate and L-cysteine, precipitated realgar (As2S2). During growth on selenate, elemental selenium was produced. The G+C content of the DNA was 58.3 mol%. Due to 16S rRNA gene sequence analysis combined with physiological and morphological criteria, the new isolate belongs to the Thermoproteales order. It represents a new species within the genus Pyrobaculum, the type species of which we name Pyrobaculum arsenaticum (type strain PZ6*, DSM 13514, ATCC 700994). Comparative studies with different Pyrobaculum-species showed, that Pyrobaculum aerophilum was also able to grow organotrophically under anaerobic culture conditions in the presence of arsenate, selenate and selenite. During growth on selenite, elemental selenium was formed as final product. In contrast to P. arsenaticum, P. aerophilum could use selenate or arsenate for lithoautotrophic growth with carbon dioxide and hydrogen.

Anaerobiosis↗
PubMed2000

Colorectal carcinomas with high microsatellite instability: defining a distinct immunologic and molecular entity with respect to prognostic markers.

Molecular analysis of hereditary nonpolyposis colorectal carcinomas (HNPCC) has identified DNA mismatch repair deficiencies with resulting microsatellite instability (MSI) as a pathway of carcinogenesis that appears to be relevant for prognosis, treatment, and possibly prevention. In this study, expression of cell cycle proteins and other known prognostic markers is correlated with the microsatellite status of colorectal cancers (CRC). One hundred consecutive cases from the CRC Registry at Thomas Jefferson University were analyzed for MSI. Immunohistochemistry was performed for the mismatch repair proteins hMLH1 and hMSH2, tumor suppressor p53, apoptosis inhibitor bcl-2, cell cycle proteins p21(WAF1/CIP1), and p27 and the proliferation markers Ki-67 and topoisomerase II. High MSI (MSI-H) is significantly correlated with loss of either hMLH1 or hMSH2, presence of bcl-2, and absence of p53. p21(WAF1/CIP1) is positive in all tumors with MSI-H. Previous findings of a lower proliferation rate were confirmed with a topoisomerase II stain. Microsatellite stable (MSS) tumors generally express both MSH2 and MLH1. Other highly significant differences are positive p53 in 56% of MSS cases and negative bcl-2 in 98% of MSS cases. p27 expression is found in approximately 50% of all CRCs irrespective of the microsatellite status. MSI-H tumors follow the mutator pathway, with loss of expression of one mismatch repair protein, wild-type p53, lower proliferation, and positivity for p21(WAF1/CIP1). MSS tumors follow the suppressor pathway, characterized by p53 overexpression, higher proliferation, and absence of bcl-2 expression; p21(WAF1/CIP1) expression can be variable. These data provide a molecular basis for the clinical observation that patients with HNPCC appear to have a more favorable prognosis. HUM PATHOL 31:1506-1514.

Adenoma↗
PubMed2000

Cognitive-behaviour therapy as a treatment for irritable bowel syndrome: a pilot study.

OBJECTIVE: The irritable bowel syndrome (IBS) is a chronic and often disabling functional bowel disorder. Psychological treatments, in particular cognitive and behavioural interventions, have been shown to be effective for this disorder. The aim of this study was to test the efficacy of a cognitive-behaviour program. METHOD: Eight participants (seven female, one male) aged between 24 and 71 years, with a diagnosis of IBS according to the Rome criteria, were recruited from among the gastroenterology outpatients at Nepean Hospital, in Sydney, Australia. Participants were administered pretreatment on measures of psychological function and bowel symptom severity. Following a 2-week baseline period, participants began a structured psychological treatment comprising eight sessions of cognitive-behaviour therapy. Throughout treatment, participants maintained daily records of symptom severity and completed homework assignments to ensure treatment compliance. The pretreatment assessment measures were repeated 1 week post-treatment. RESULTS: After treatment, five of the eight patients no longer met the Rome diagnostic criteria for IBS. There was no significant reduction in bowel symptom frequency. There were, however, significant improvements in the distress and disability associated with bowel symptoms. Anxiety and depression were also significantly reduced. CONCLUSIONS: Cognitive-behaviour therapy reduced the distress and disability associated with IBS, but not the frequency of bowel symptoms. This supports the proposed cognitive model for IBS, and cognitive-behaviour therapy appears to have its effect by altering the cognitive response to visceral hypersensitivity.

Adult↗
PubMed2000

Superior labrum anterior-posterior lesions: diagnosis with MR arthrography of the shoulder.

PURPOSE: To determine the accuracy of magnetic resonance (MR) arthrography in the diagnosis of superior labrum anterior-posterior (SLAP) lesions of the shoulder. MATERIALS AND METHODS: From January 1995 to June 1998, MR arthrography of the shoulder was performed in 159 patients with a history of chronic shoulder pain or instability. Fifty-two patients underwent arthroscopy or open surgery 12 days to 5 months after MR arthrography. Diagnostic criteria for SLAP lesion included marked fraying of the articular aspect of the labrum, biceps anchor avulsion, inferiorly displaced bucket handle fragment, and extension of the tear into the biceps tendon fibers. Surgical findings were correlated with those from MR arthrography. RESULTS: SLAP injuries were diagnosed at surgery in 19 of the 52 patients (37%). Six of the 19 lesions (32%) were classified as type I, nine (47%) as type II, one (5%) as type III, and three (16%) as type IV. MR arthrography had a sensitivity of 89% (17 of 19 patients), a specificity of 91% (30 of 33 patients), and an accuracy of 90% (47 of 52 patients). The MR arthrographic classification showed correlation with the arthroscopic or surgical classification in 13 of 17 patients (76%) in whom SLAP lesions were diagnosed at MR arthrography. CONCLUSION: MR arthrography is a useful and accurate technique in the diagnosis of SLAP lesions of the shoulder. MR arthrography provides pertinent preoperative information with regard to the exact location of tears and grade of involvement of the biceps tendon.

Adult↗
PubMed2000

HyCoSy--as good as claimed?

Hysterosalpingo contrast sonography (HyCoSy) has been compared favourably in the literature with hysterosalpingography (HSG). It does not require ionizing radiation and demonstrates the uterus and ovaries. HyCoSy is reported as being a safe, well tolerated, quick and easy investigation of Fallopian tube patency. Over a 1-year period HyCoSy was performed by two operators on 118 consecutive women who were thought likely to have patent Fallopian tubes. The examinations were graded using a local scale to assess discomfort and were correlated with tubal patency. HSG was performed on 116 patients by the same operators and discomfort recorded. 15 patients underwent both examinations. The degree of pain or reaction was graded 0 (no pain) to 4 (maximum) according to a locally devised scale. Costs of the two examinations were estimated. 89 patients examined by HyCoSy were graded 0-2. However, 23 had severe protracted pain and/or vasovagal reactions with bradycardia and hypotension. Of these, seven required resuscitation owing to prolonged symptoms, requiring treatment with atropine. 19 of the 23 had bilaterally patent Fallopian tubes. Where subsequent HSG was performed, tubal occlusion was confirmed in 8 of 15 women. Other pathologies were noted in 29 of the HyCoSy patients and there were six technical failures. During the same period no severe adverse reactions occurred in 116 patients having HSG performed by the same operators. Three of the HSG examinations were technically unsuccessful. Discomfort following HyCoSy was much greater than that reported previously. Possible mechanisms are discussed but it does not appear to be related to tubal occlusion. Diagnostic accuracy, costs and discomfort compare unfavourably with HSG.

Fallopian Tube Patency Tests↗
PubMed2000

An integrated program for evidence-based medicine in medical school.

To provide optimal care for their patients, clinicians must be able to locate and interpret the most current literature. Teaching the necessary skills to medical students is essential, if we wish to train clinicians to be able to keep up with the expansion of biomedical knowledge for their entire working lives. In this paper, we describe our school's four-year curriculum in evidence-based medicine and the performance of three senior classes on the summative evaluation exercise devised to measure the program's success.

Curriculum↗
PubMed1999

A single growth cone is capable of integrating simultaneously presented and functionally distinct molecular cues during target recognition.

A variety of cell recognition pathways affect neuronal target recognition. However, whether such pathways can converge at the level of a single growth cone is not well known. The RP3 motoneuron in Drosophila has previously been shown to respond to the muscle cell surface molecules TOLL and fasciclin III (FAS3), which are normally encountered during RP3 pathfinding in a sequential manner. TOLL and FAS3, putative "negative" and "positive" recognition molecules, respectively, affect RP3 antagonistically. Under normal conditions, TOLL and FAS3 together improve the accuracy of its target recognition. Here, we show that, when presented with concurrent TOLL and FAS3 expression, RP3 responds to both, integrating their effects. This was demonstrated most succinctly by single cell visualization methods. When a balance in relative expression levels between the two antagonistic cues is achieved, the RP3 growth cone exhibits a phenotype virtually identical to that seen when neither TOLL nor FAS3 is misexpressed. Thus, growth cones are capable of quantitatively evaluating distinct recognition cues and integrating them to attain a net result, in effect responding to the "balance of power" between positive and negative influences. We suggest that the ability to integrate multiple recognition pathways in real-time is one important way in which an individual growth cone interprets and navigates complex molecular environments.

Animals↗
PubMed1999

Microdispensing technologies in drug discovery.

Because of the advent of managed care,the pharmaceutical industry is entering a new era, characterized by increased competition and pricing pressures. As a result, drug discovery within pharmaceutical companies is rapidly embracing new paradigms to help bring more novel drugs to the market as rapidly as possible. One paradigm currently being pursued is the miniaturization of the processes involved in the exploratory phase of drug discovery. This reduction in scale has led to the development of new dispensing technologies. This review examines several microdispensing technologies for drug discovery.

Journal Article↗