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Biomedical subjects

A Turk

Publications and source records attributed to A Turk.

At least 19 recordsLinked to original sources

Do we need to measure total serum IgA to exclude IgA deficiency in coeliac disease?

BACKGROUND: Screening for IgA deficiency in patients with coeliac disease is essential because of the increased incidence of IgA deficiency associated with the disease, which usually relies on the estimation of IgA levels in each case. AIM: To devise a method of excluding IgA deficiency without measuring total serum IgA in each case. MATERIALS AND METHODS: The optical density readings on enzyme-linked immunosorbent assay (ELISA) of 608 routine samples received for tissue transglutaminase (TTG) antibody testing for coeliac disease were compared with their total IgA concentrations. Dilution experiments were also carried out to ensure linear relationships between optical density on ELISA and IgA concentrations and to compare the sensitivities for TTG and endomysium antibodies in TTG-positive samples. RESULTS AND DISCUSSION: A clear relationship was shown between total IgA concentration and TTG optical density readings by ELISA. To ensure a positive TTG result if antibodies are present, it was possible to recommend an optical density level above which all samples have sufficient IgA. Samples with optical density <0.05 should be investigated further by estimating total IgA and, if low, samples should be subjected to immunofluorescence microscopy testing for IgA and IgG endomysium antibodies. CONCLUSIONS: An easier, more cost-effective and practical way of excluding IgA deficiency in the investigation on coeliac disease is reported.

Autoantibodies↗

Recording CSF pressure with a transducer-tipped wire in an animal model of Chiari I.

In dogs, a wire with a pressure-sensitive transducer was inserted percutaneously into the subarachnoid space and manipulated under fluoroscopic monitoring in the posterior fossa or upper cervical spinal canal. Pressure recordings from the wire showed fluctuations in pressure corresponding to the cardiac cycle. When a balloon was distended in the foramen magnum, maximum and minimum pressures increased. Continuous monitoring of CSF pressure remote from the site of cannulation was feasible with a wire-based pressure transducer.

Animals↗

[Quality of long-term oral anticoagulation: an observation study].

The aim of this observation study was to analyse the quality of the oral anticoagulation in a non-randomised field. Prospectively all patients with an oral anticoagulation were registered when entering the hospital. An assessment was made of the indication for the oral anticoagulation, the co-medication (especially the ones that influence the effect of the anticoagulation), the current International Normalized Ratio (INR), as well as any possible complications. All INR values were taken from the personal anticoagulation card of the patient. 140 patients were identified for the study. 16% of these patients had no obvious indication for an oral anticoagulation. Of the 1278 registered INR values, 582 (46%) were within the recommended range, according to the common guidelines. 359 (28%) INR values were too high and 337 (26%) were too low. 39 (28%) anticoagulation cards had been kept with the prothrombin time instead of INR measurements. The results of this observation survey show that the quality of the oral anticoagulation in a non-randomised field is mostly insufficient.

Administration, Oral↗

Endovascular treatment of experimental canine aneurysms: feasibility with MR imaging guidance.

PURPOSE: To evaluate the feasibility of using magnetic resonance (MR) imaging to guide and monitor endovascular therapeutic procedures. MATERIALS AND METHODS: Endovascular therapeutic procedures were performed with MR imaging guidance in eight dogs by using a 1.5-T MR unit with echo-planar imaging capabilities. Carotid arterial aneurysms were surgically created in four dogs. The ability to depict, track, and position catheters, guide wires, and Guglielmi detachable coils was assessed. Catheters were first positioned with fluoroscopic guidance. Tracking and depiction were achieved with MR imaging by using commercially available catheters filled with a gadopentetate dimeglumine solution and a fast, two-dimensional, time-resolved, variable-rate k-space sampling technique. RESULTS: When either a catheter or the coaxial space between a catheter and a guide wire was filled with a solution of gadopentetate dimeglumine, catheter movement was always depicted. In the animals with aneurysms, it was possible to depict movement of a catheter into and out of the aneurysm. This was achieved by superimposing reconstructed images obtained during catheter movement onto a previously acquired MR angiogram ("road map"). Prototype Guglielmi detachable coils were successfully positioned and detached. Aneurysm obliteration was monitored with the acquisition of new road map images. CONCLUSION: The results demonstrate the feasibility of using MR imaging to guide endovascular therapeutic procedures.

Aneurysm↗

Basic fibroblast growth factor and transforming growth factor beta-1 expression in the developing dura mater correlates with calvarial bone formation.

Numerous studies have found dura mater-calvarial mesenchyme interactions during calvarial bone induction; however, the exact molecular mechanisms governing these inductive events remain unknown. Recent studies have implicated basic fibroblast growth factor (FGF-2) and transforming growth factor-beta1 (TGF-beta1) in regulating bone formation. The purpose of this study was, therefore, to investigate the expression of FGF-2 and TGF-beta1 during calvarial bone formation in rats. Eight rats were killed on embryonic days 14, 18, and 20 and neonatal day 1 (n = 32). Four animals at each time point were analyzed by in situ hybridization, and the remainder were analyzed by immunohistochemistry. The results indicated that the dura mater underlying the developing calvarial bone strongly expressed FGF-2 and TGF-beta1 mRNA at all time points examined. In contrast, minimal growth factor expression was noted in the overlying calvarial mesenchyme until embryonic day 18, but it increased significantly with increasing age. Importantly, FGF-2 and TGF-beta1 mRNA expression in the dura mater underlying the developing calvarium preceded and was significantly greater than expression in the calvarium mesenchyme (p < 0.05). Interestingly, minimal expression of FGF-2 and TGF-beta1 mRNA was noted for all time points in the dura mater underlying the posterior frontal suture and within the posterior frontal suture connective tissue (p < 0.01 when compared with the dura mater underlying the developing calvarium). Immunohistochemical findings closely paralleled mRNA expression, with intense staining for FGF-2 and TGF-beta1 in the dura mater underlying the developing calvarial mesenchyme. Increasing FGF-2 and TGF-beta1 staining was noted within calvarial osteoblasts with increasing age, particularly in cells located near the endocranial surface (i.e., in contact with the developing dura mater). These findings, together with the known biologic functions of FGF-2 and TGF-beta1, implicate these growth factors in the regulation of calvarial bone growth by the developing dura mater. The possible mechanisms of this interaction are discussed.

Animals↗

Increased gastrointestinal symptoms in chronic alcoholics.

Although chronic alcoholics frequently present with gastrointestinal (GI) symptoms, the precise prevalence of GI symptoms in this group is unknown. Accordingly, we compared the frequency and severity of GI symptoms in 48 male alcoholics with those of 48 nonalcoholic controls. A standardized questionnaire was administered on two separate occasions to all subjects, and 14 GI symptoms were evaluated for three periods (during active drinking, early withdrawal, and sobriety). Symptom severity was assessed with a visual analog scale (1-10). Both actively drinking and withdrawing alcoholics had more frequent heartburn, nausea, vomiting, diarrhea, and flatulence, and more severe chest pain, milk intolerance, and postprandial fullness. These symptoms were transient and did not correlate with the quantity of alcohol consumed. Thus, alcoholics have more frequent and more severe GI symptoms which resolve quickly during abstinence and which predominantly occur while actively drinking rather than during withdrawal.

Adult↗

Smell of danger: an analysis of LP-gas odorization.

LP-gas derives warning properties from the odorants ethyl mercaptan or thiophane. Laboratory tests have implied that the average person has the ability to smell the odors before leaking LP-gas reaches one-fifth its lower limit of flammability. Generally, however, laboratory tests ignore or discard persons with a poor sense of smell, especially the elderly and persons with certain types of hyposmia. Some persons who apparently can smell the warning agents when directed may otherwise fail to notice or identify them. Elderly men seem particularly vulnerable to instances of incidental anosmia and olfactory agnosia. Psychophysical testing of the warning agents has been rather unsophisticated. There exists neither a standard protocol for testing nor adequate specification of the perceptual properties that might make one warning agent better than another. Without such developments, improvement in warning agents will fail to occur. Possible improvements include increases in concentration, the use of blends to insure more uniform delivery of agent and, to decrease the perceptual vulnerability of relatively insensitive people, use of agents with favorable psychophysical (stimulus-response) functions and use of agents with favorable adaptation characteristics. Even without a change in existing products, it seems advisable to learn more about the vulnerability of LP-gas users and to employ educational means to reduce risks.

Diffusion↗

Penicillin hypersensitivity in systemic lupus erythematosus.

The prevalence of positive immediate-type skin tests to penicillin antigens among patients with systemic lupus erythematosus (SLE) was compared with hospitalized controls without SLE and found not to differ significantly. On the other hand, we confirmed previous reports that the prevalence of histories of prior penicillin reaction was significantly higher in SLE patients than among controls. This is felt to be related to the primary disease process, and we conclude that patients with SLE do not have an increased risk of IgE-mediated allergic reactions to penicillin.

Antigens, Fungal↗