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Biomedical subjects

D Steiner

Publications and source records attributed to D Steiner.

At least 19 recordsLinked to original sources

Microvascular ischemia-reperfusion injury in striated muscle: significance of "no reflow".

"No reflow" has been implicated as prominent phenomenon in microvascular injury associated with ischemia-reperfusion (I/R). The objectives of this study were 1) to elucidate the significance of no reflow in microvascular I/R injury of striated muscle and 2) to determine whether reactive oxygen metabolites play a role in the development of postischemic no reflow. By use of the hamster dorsal skinfold preparation and intravital microscopy, microvascular perfusion of capillaries and postcapillary venules of striated muscle was quantitatively assessed before and 30 min, 2 h, and 24 h after 4 h of tourniquet-induced ischemia. I/R was characterized by a significant reduction (P < 0.01) in functional capillary density to 35% of baseline values during initial reperfusion, with incomplete recovery after 24 h (n = 9). In addition, capillary perfusion was found to be extremely heterogeneous, and wall shear rate in postcapillary venules was significantly decreased (P < 0.01). Treatment with either superoxide dismutase (SOD; n = 9) or allopurinol (n = 9) resulted in maintenance of capillary density of 60% of baseline (P < 0.05). Furthermore, I/R-induced capillary perfusion inhomogeneities and decrease of wall shear rate in venules were attenuated significantly (P < 0.01) by SOD and allopurinol. Thus part of capillary perfusion disturbances during I/R in striated muscle may be caused by increased postcapillary vascular resistance, probably mediated by reactive oxygen metabolites. However, the fact that in SOD- and allopurinol-treated animals 40% of the capillaries were still found to be nonperfused indicates that mechanisms other than oxygen radicals play an important role in the development of postischemic no reflow.

Allopurinol

Microvascular ischemia-reperfusion injury in striated muscle: significance of "reflow paradox".

Ischemia-reperfusion (I/R)-induced microvascular injury is characterized by capillary "no-reflow" and reflow-associated events, termed "reflow paradox," including leukocyte-endothelium interaction and increase in microvascular permeability. The major objectives of this study were 1) to elucidate the significance of reflow paradox after 4 h of tourniquet-induced ischemia in striated muscle and 2) to determine the role of reactive oxygen metabolites in the pathogenesis of reflow paradox-dependent microcirculatory alterations. By use of in vivo fluorescence microscopy in a striated muscle preparation of hamsters, leukocyte-endothelium interaction in postcapillary venules and macromolecular extravasation from capillaries and venules were quantified before ischemia and after 30 min, 2 h, and 24 h of reperfusion. I/R elicited marked enhancement (P < 0.01) of leukocyte rolling during initial reperfusion and a 20-fold increase of leukocyte adherence (P < 0.01) lasting for the entire postischemic reperfusion period (n = 7). These phenomena were accompanied by significant leakage (P < 0.01) of macromolecules from capillaries and in particular from postcapillary venules (n = 9). Both superoxide dismutase (SOD, 20 mg/kg body wt, n = 7) and allopurinol (50 mg/kg body wt, n = 7) were effective in attenuating I/R-induced leukocyte rolling and adherence. In addition, microvascular leakage was significantly reduced by allopurinol (n = 9) and completely abolished by SOD (n = 9) (P < 0.01). These results support the concept that reactive oxygen metabolites contribute to I/R-induced reflow paradox, resulting in leukocyte accumulation, adherence, and increase in microvascular permeability.

Allopurinol

Evaluation of humoral responsiveness in children.

The evaluation of postvaccine antibody responses can provide a reasonably convenient and useful adjunct to the evaluation of possible humoral immune dysfunction syndromes. In patients whose clinical history is suspicious for an antibody deficiency syndrome, such studies can document normal antibody responsiveness. On the other hand the wide age-dependent variation in antibody responses makes careful interpretation necessary in concluding that a patient falls outside the "normal" pattern of antibody responsiveness. Finding a patient well below the mean values for age for multiple vaccines in concert with an appropriate clinical history would strongly suggest an abnormality of immune regulation. At this time the finding of abnormal antibody responses does not always imply that intervention with immunoglobulin therapy is indicated or that it would lead to improvement in clinical symptoms. It might help justify prophylactic antibiotic programs, however, similar to those used for recurrent otitis media. Interpretation of antibody responses in children younger than 2 years of age is probably hazardous since many patients may have relative retardation in their normal development of polysaccharide antibody responsiveness. Such patients usually develop a normal response as they grow older and do not need long term therapy. Until new technologies for measuring immune competence are developed, the above-mentioned measures of humoral immunity, when combined with clinical judgment, should be adequate to guide clinical decision-making in most cases.

Adolescent

[Indoor hockey: injuries and prevention].

Frequency and mechanisms of injuries in women's indoor-hockey are evaluated in a retrospective study of 89 players. Each athlete sustains 1.1 injury per season on the average. The goalkeeper's risk is about three times as high as that of the outfield players. The risk during match exceeds the risk during practice by a factor of 20. The most common site of injury is the lower limb (55%), 39% are related to the upper limb, 5% to head and trunk. Half of the lesions are caused by ball and stick, they involve especially hands and fingers. The facts allow to draw conclusions concerning preventive measures. The players must be protected by better equipment, special exercises and further development of the rules.

Adolescent

Depression in the elderly. Characteristics and clinical management.

Major depression and clinically significant depressive symptoms occur commonly in the community-dwelling, medically ill, and institutionalized elderly. Both major depression and depressive symptoms need thorough evaluation and treatment because of the significant morbidity and mortality associated with these syndromes. Depression may be difficult to diagnose, especially in the medically ill elderly, because of the masking of depressive symptoms by somatic complaints or the presumption that symptoms are attributable to concurrent medical illness. Therefore, the clinician must be alert to the possibility of depression in the elderly patient. Although no specific diagnostic test is available, rating scales can be useful in screening for depression in the elderly patient. It is necessary to rule out medical illness or medications as contributing factors to depression. Psychotherapy and psychopharmacology, alone or in combination, are effective treatments for most elderly patients with depression. ECT is a safe and effective treatment for major depression in this population. Depression in the elderly is potentially a chronic and relapsing illness with significant associated medical and social morbidity. Because of their frequent contact with the elderly, nurses play a particularly important role in the diagnosis and treatment of depression. They need to recognize typical and atypical symptoms of depression and must be familiar with the potential side effects of antidepressant treatment. Close monitoring for these potential side effects can minimize disability. By working as a team with physicians, psychologists, and others, nurses have a necessary role in the care of the elderly depressed patient.

Aged

Anaphylaxis and desensitization to the murine monoclonal antibody used for renal graft rejection.

The murine monoclonal antibody muromonab CD3 is currently used to reverse acute renal graft rejection. We report a case of systemic anaphylaxis during a muromonab CD3 infusion despite pretreatment with systemic antihistamines and corticosteroids. Rapid intravenous desensitization was performed the following day without untoward reactions and daily muromonab CD3 infusions were successful in reversing renal graft rejection. A second rapid desensitization to CD3 was performed 1 month later without any complications. Serum muromonab CD3-specific IgG and IgE antibodies were detected in serum samples obtained after the anaphylactic reaction. The anaphylactic reaction to muromonoab CD3 monoclonal antibody could have been due to allergen-specific antibodies noted in postreaction serum or a cross-reactive antibody to mouse antigens or both. More importantly, this case illustrates that rapid desensitization can be performed successfully without serious complications; therefore, systemic anaphylaxis can develop in susceptible atopic individuals receiving muromonab CD3 monoclonal antibody for renal graft rejection.

Adolescent

[Chronic impingement syndrome of the shoulder].

The most common manifestation of periarthritis of the shoulder is the chronic impingement syndrome, which represents an "entrapment situation". When the arm is raised, the supraspinatus tendon that forms part of the rotator cuff, comes into contact with the coracoacromial arch. The complains can often be improved by conservative treatment. If, however, the problem persists--in about 10 to 20% of the cases--surgical decompression of the coracoacromial arch by resecting the coracoacromial ligament and the subacromial bursa is indicated. This limited intervention carries only a low risk and, as studies have shown, has such a high rate of success that, in the individual case, the indication for surgery can be established earlier than has so far been assumed.

Bursa, Synovial

[Topography of the upper biceps tendon segment].

26 shoulders are studied by polariscopic and histologic examination. It can be confirmed that the origin of the long biceps tendon is not only at the supraglenoid tubercle, but also y-shaped in the glenoid labrum. This finding can be explained by phylogenetic means. Further details are found during the course of the tendon through the bicipital groove. A mesotenonium is seen regularly. This is fixed either to the roof or the ground of the sulcus by a band of connective tissue. It is shown also, that the roof of the groove is not a ligament (ligamentum transversum humeri) but consists of collagen fibers continuing from the subscapularis and capsular attachment at the lesser tubercle.

Adult

Audiotaped versus written administration of the Situational Competency Test.

The Situational Competency Test (SCT) is an audiotaped, verbal role-play measure of coping responses to eight drinking and eight non-drinking situations. The present investigation evaluated the comparability of response scores to audiotaped versus written administrations of the SCT in two samples of alcohol clients. The written administration of the SCT yielded significantly shorter durations of response in both clinical samples, but there were no other significant differences between the administration methods on the other scoring dimensions. Correlations of the audiotaped and written summary scores revealed no consistently significant or meaningful associations. Given the differences in duration, the generally poor correlations between summary scores, and the loss of the latency measure in the written format, we recommend retention of the audiotaped administration for use in research.

Adaptation, Psychological

Arterial supply of the human long biceps tendon.

The present study deals with the question whether an insufficient vascular supply of certain areas can be made responsible for ruptures in the biceps tendon. The macroscopic and microscopic examination shows that the blood supply of the tendon in the part most prone to ruptures, that is in the bicipital groove, is guaranteed even in older individuals. It is at least much better than in the intra-articular portion where ruptures are seldom observed. This means that mechanical components such as friction are dominant. The vascular factors seem to play a minor part.

Adult

Papillary circulation dynamics in glaucoma.

The ability of glaucomatous eyes to adjust to a sudden increase in intraocular pressure was investigated in nine certain glaucoma cases and in ten normal subjects. The "dynamic provoked circulatory response" (DPCR) was determined by continuously measuring the brightness of the papilla before (baseline), during, and after an abrupt artificial elevation in intraocular pressure. Following the onset of intraocular pressure elevation, the period during which the baseline brightness of the papilla persisted (latency time) was significantly (P less than 0.001) shorter in glaucomatous eyes (0.64 +/- 0.25 s) than in normal eyes (2.39 +/- 0.68 s). This led to the suggestion that the extent to which an eye can adjust to abruptly higher intraocular pressure is measurably reduced in glaucoma. That this effect can be quantified indicates a potentially useful method for detection and follow-up of glaucoma.

Aged

[Shoulder and transducer position in sonographic soft tissue diagnosis. Anatomic principles].

The positions of the arm and of the transducer for the sonographic detection of soft tissue disorders of the shoulder have not yet been standardised. Anatomical studies were performed on 16 shoulders in different rotatory positions according to applied sonographic planes. 4 images in 3 different shoulder positions are necessary to evaluate the clinical important areas as completely as possible. With regard to the time and cost involved, this expenditure is acceptable in daily routine work.

Aged

A comparison of two ambulatory blood pressure monitors, the Del Mar Avionics Pressurometer IV and the Spacelabs 90202.

The purpose of this study was to evaluate the accuracy of two noninvasive ambulatory blood pressure (BP) monitors, the new Del Mar Avionics Pressurometer IV (PIV) and the second generation Spacelabs 90202. Two sets of comparisons were made between two trained observers and the monitors on 17 normotensive and 28 hypertensive subjects. The result of the first comparison showed that the average difference between observers and the PIV was 1.2/-2.2 mm Hg for systolic and diastolic BP. Comparisons of both monitors to the observers showed differences of 0.9/1.0 mm Hg for the PIV and 0.3/0.8 mm Hg for the 90202 (systolic/diastolic). Correlations between the average observer reading and the monitors over both sets of comparisons ranged from 0.90 (diastolic 90202 vs observer) to 0.98 (systolic PIV vs observer). The percentage of readings within 5 mm Hg between observer and monitor over all comparisons ranged from a low of 68% (90202, systolic and diastolic) to a high of 83% (PIV, diastolic). In general, both devices are satisfactory and reliable machines for ambulatory BP monitoring, but each has a slightly different bias compared to auscultatory readings.

Adult

Bioconstruction of the extrahepatic biliary duct system in minipigs. Comparing normal condition with experimental obstruction.

The extrahepatic biliary duct system is subject to a particular bioconstruction to secure its bile transport function. The dominant structure of the bile duct wall is a network of collagen fibres harboring muscle-fibre bundles. The collagen fibres are virtually inelastic, volumes can be changed only by rearranging the network. The ducts show different spatial arrangements of the fibres causing different extents of dilatation during obstruction. Extreme dilatation might cause a rupture of the network, and deficient postoperative retonisation could be the result.

Animals

Collagen fiber arrangement of the human shoulder joint capsule--an anatomical study.

The polariscopic examination of isolated shoulder joint capsules shows that the entire capsule does not have a homogeneous collagen structure. Most of the capsule is characterized by regular collagen fibers which cross at an obtuse angle in the area of the musculus supraspinatus and at an acute angle in the area of the m. infraspinatus. The density of the collagen network increases from the medial to the lateral part. Deviating from this basic pattern of the joint capsule, there is a different collagen texture in the area between the m. supraspinatus and the m. subscapularis. This texture has dissociated, rarefied and irregular collagen fibers. This means that the area--in comparison with the remainder of the capsule--is characterized not only by missing reinforcing ligaments but also by a deviating pattern of the collagen fibers. This different collagen structure is already existent in the fetus.

Adult

[Current and known aspects of the arterial supply of the rotator cuff].

The basic arterial supply of the shoulder is well known, some details for example the supply of the m. supraspinatus are not studied yet. Preparation of shoulder-specimens after injection of silicone-caoutchouc are done to examine the vascular system. The arterial supply of the shoulder is described as a system of four rings. The results are discussed in combination with the literature.

Arteries