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Biomedical subjects

J Krauss

Publications and source records attributed to J Krauss.

At least 55 records · Page 3Linked to original sources

Increased endothelin and creatine kinase after electrical stimulation of paraplegic muscle.

The purpose of this study was to assess changes in creatine kinase (CK) and endothelin (ET) in individuals with spinal cord injury (SCI) after computerized functional electrical stimulation leg ergometry (CFES LE). Eight subjects (7 male and 1 female) with complete spinal cord lesions (C7 to L1) completed zero-loaded CFES LE tests at baseline, after 3, 6, and 12 wk of CFES LE training (30 min, 3 times/wk), and also after detraining (DT) (n = 5). Venous blood samples were drawn 24, 48, and 72 h after CFES LE for measurement of ET and CK. The CK response was largest (peak CK) 72 h after baseline tests (28.2 +/- 6.0 to 895.7 +/- 345.9 ktals/l) and was no different from baseline by weeks 3, 6, and 12. After DT, CK was similar before and after CFES LE (153.8 +/- 19.0 and 189.7 +/- 34.5 ktals/l, respectively). CFES LE also significantly increased peak ET after baseline (from 11.7 +/- 1.5 to 18.0 +/- 2.5 pg/ml). During the subsequent training, peak ET remained significantly higher than the baseline value at weeks 3, 6, and 12 (20.2 +/- 1.8, 18.0 +/- 1.1, and 16.9 +/- 2.2 pg/ml, respectively). After DT, peak ET increased significant relationship (r = 0.44) existed between ln peak CK activity and peak ET. In summary, the increase in circulating ET in spinal cord-injured individuals may have implications for baroreceptor function and therefore blood pressure control in SCI. Further research into CFES LE, ET, and baroreceptor function in SCI is warranted.

Adult↗

Regulation of dopamine receptors by bupropion: comparison with antidepressants and CNS stimulants.

Acute treatment of rats with the antidepressant bupropion increased [3H]spiperone binding to D2 receptors in vivo. This dose- and time-dependent effect was greatest in striatum and minimal in cerebellum and pituitary. A parallel behavioral stimulation occurred in the same rats. Among 21 antidepressants and CNS stimulants tested, only those that activate dopamine (DA) transmission had similar effects: nomifensine, amineptine, methylphenidate, D-amphetamine, amfonelic acid, cocaine, benztropine and GBR 12909. Decreasing DA transmission with reserpine plus alpha-methyl-p-tyrosine prevented the action of bupropion. Finally, bupropion was inactive in vitro and ex-vivo. Therefore, we propose that bupropion and other DA-enhancing agents modify the characteristics of [3H]spiperone binding through the intervention of a dynamic regulation of the D2 receptors by the neurotransmitter itself.

Animals↗

Anticardiolipin antibodies: a study of frequency in TIA and stroke.

We undertook a prospective study of consecutive patients to determine the frequency of elevated IgG and IgM anticardiolipin antibodies in transient ischemic attack and ischemic stroke and found elevated IgG antibodies in 8.2% (9 of 110) and IgM in 9.1% (10 of 110), only the former being significantly greater than in a healthy control population. We suggest that anticardiolipin screening be concentrated on the young.

Antibodies↗

Endogenous dopamine (DA) modulates [3H]spiperone binding in vivo in rat brain.

[3H]spiperone (SPI) binding in vivo, biochemical parameters and behavior were measured after modulating DA levels by various drug treatments. DA releasers and uptake inhibitors increased SPI binding in rat striatum. In other brain areas, the effects were variable, but only the pituitary remained unaffected. Surprisingly, nomifensine decreased SPI binding in frontal cortex. The effects of these drugs were monitored by measuring DA, serotonin (5-HT) and their metabolites in the same rats. The increased SPI binding in striatum was parallel to the locomotor stimulation with the following rank order: amfonelic acid greater than nomifensine greater than D-amphetamine greater than or equal to methylphenidate greater than amineptine greater than bupropion. Decreasing DA levels with reserpine or alpha-methyl-para-tyrosine reduced SPI binding by 45% in striatum only when both drugs were combined. In contrast, reserpine enhanced SPI binding in pituitary. Thus, the amount of releasable DA seems to modulate SPI binding characteristics. It is suggested that in vivo, DA receptors are submitted to dynamic regulation in response to changes in intrasynaptic concentrations of DA.

Animals↗

Movement of hemostatic clips from the ventricles through the aqueduct to the lumbar spinal canal. Case report.

The authors report a patient in whom rebleeding after operation for a left temporal arteriovenous malformation resulted in the dislocation of multiple hemostatic clips. Several clips, including a Yasargil aneurysm clip, were detected incidentally in the lumbar spinal canal. No clinical signs or symptoms were noted. Retrospectively, passage of the aneurysm clip through the aqueduct could be detected on computerized tomography scans performed to evaluate a series of epileptic seizures.

Cerebral Angiography↗

A case of "accessory falx cerebri".

We report on a 12-year-old boy who underwent a right frontotemporoparietal craniotomy for complete extirpation of three cavernous hemangiomas of the temporal lobe. On this occasion, an accessory dural septum was observed that spanned, in the direction of the corona, the temporo-occipital base upward to the lower parietal area. It produced a deep notch in the cortex, was supplied by a small leptomeningeal artery, and probably contained small venous sinus. Embryological considerations and clinical relevance are discussed.

Child↗

[Lumbosacral nerve root avulsion. Diagnosis using computed tomography, magnetic resonance tomography and myelography].

Root lesions in the lumbo-sacral region are rare, compared with injuries of the roots of the brachial plexus. They occur almost exclusively in association with serious injuries of the pelvis. The present case, without pelvic injury, is a rarity. The appearances on myelography and CT are well known, but the findings on MRI are also described and the value of this non-invasive procedure is discussed.

Adult↗

[Leakage measurements with the dye extraction method and direct methotrexate level determination (enzyme immunoassay) during and after regional cytostatic limb perfusion].

The dye stuff extinction-method stood the test for checking the separation between the regional and the systemic circulation during the perfusion of extremity tumors by cytostatic drugs. On the other hand the use of an enzyme immunoassay for direct methotrexate-level measuring in serum is recommendable in the postoperative phase. Complications by methotrexate are recognized early by means of an enzyme immunoassay and an individualized application is possible.

Chemotherapy, Cancer, Regional Perfusion↗

Hydrocephalus in craniosynostosis.

Routine CT scanning in 221 patients with craniosynostosis revealed ventricular dilation in 40. In 5 hydrocephalus was obviously unrelated to the craniostenosis. The remaining 35 cases were associated almost exclusively with syndromic craniosynostosis. Ventricular dilation was mild in 22, moderate in 9, and marked in 4 patients. Clinical and radiological findings strongly suggest that three different mechanisms are involved in the pathogenesis of hydrocephalus: primary cerebral maldevelopment, brain atrophy, and CSF outflow obstruction. In the diagnosis of hydrostatic hydrocephalus with craniosynostosis, head circumference is no indicator of progressive hydrocephalus, and intracranial hypertension may be due either to CSF accumulation or to craniostenosis. The present study indicates that shunt treatment prior to correction of synostosis should be restricted to a few cases of rapidly progressing hydrocephalus. Secondary shunting of hydrocephalus may be considered if intracranial pressure remains high despite adequate cranial decompression. Shunting is not an appropriate treatment for craniostenosis--even in cases of concurrent ventricular dilation.

Adolescent↗

Structural relationship between the polyagglutinable antigen and the core polysaccharide of Pseudomonas aeruginosa.

It has been observed that each strain of the Pseudomonas aeruginosa species harbours the so-called polyagglutinable antigen (PA). Some strains may produce it in a form which is linked to the core moiety of lipopolysaccharide (LPS) and this type of PA can thus be detected by passive haemagglutination using the isolated LPS as coating antigen. Other strains synthesize PA exclusively in a free form, which is also coextractable with LPS, its presence can, however, be demonstrated by the haemagglutination inhibition test. From a polyagglutinable strain of P. aeruginosa an R-type LPS was isolated having the core-linked PA. This LPS preparation was highly immunogenic with regard to its PA moiety. The core-bound PA seems to exert an immunosuppression on the core region, hence, the polyagglutinable strains isolated from cystic fibrosis patients only engender anti-PA antibodies, whereas antibodies against both, side chain and core region of LPS, are not engendered. The mucoid exopolysaccharide also contains the PA which could possibly play an important role in the patient by protecting P. aeruginosa cells against anti-PA antibodies.

Antibodies, Bacterial↗

Interaction of the D1 receptor antagonist SCH 23390 with the central 5-HT system: radioligand binding studies, measurements of biochemical parameters and effects on L-5-HTP syndrome.

The interaction of SCH 23390 with dopamine (DA) and serotonin (5-HT) systems has been examined in vivo and in vitro. Like selective 5-HT2 blockers, SCH 23390 inhibited in vivo [3H]spiperone binding in the rat frontal cortex (ID50: 1.5 mg/kg) without interacting at D2 sites. SCH 23390 was equipotent to cinanserin and methysergide. In vitro, SCH 23390 inhibited [3H]ketanserin binding to 5-HT2 sites (IC50 = 30 nM). Biochemical parameters linked to DA and 5-HT were not changed excepted in striatum where SCH 23390 increased HVA and DOPAC. In the L-5-HTP syndrome model, SCH 23390 clearly showed antagonism of 5-HT2 receptors. SCH 23390 had weak affinity for 5-HT1B (IC50 = 0.5 microM), 5-HT1A (IC50 = 2.6 microM) and alpha 1-adrenergic receptors (IC50 = 4.4 microM).

5-Hydroxytryptophan↗

The D-1 dopamine receptor antagonist SCH 23390 also interacts potently with brain serotonin (5-HT2) receptors.

The interaction of SCH 23390 with central serotonin 5-HT2 receptors was studied in vivo on [3H]spiperone binding and in vitro on [3H]ketanserin binding. SCH 23390 inhibited [3H]spiperone binding in rat frontal cortex with an ID50 of 1.5 mg/kg i.p., thus being equipotent to the two 5-HT2 antagonists cinanserin and methysergide. In vitro, SCH 23390 competed with [3H]ketanserin with an IC50 of 30 nM. These data indicate that SCH 23390 also binds with high affinity to 5-HT2 receptors in rat brain.

Animals↗

[Renal dipeptidylpeptidase IV excretion in drug-induced kidney changes].

The course of the excretion of dipeptidyl-peptidase IV (DP IV)-alanine aminopeptidase, beta-glucuronidase and total protein with the urine was investigated during the treatment of 11 patients with pyelonephritis with gentamicin, after application of a renal radiographic contrast medium in 7 patients with arterial hypertension and after regional perfusion of an extremity in 10 patients with malignant melanoma. In the reference group in male test persons with 147.0 nmol/s X l a higher DP IV activity in the urine was recognized than in the female test persons (100.0 nmol/s X l). After application of the drugs a rhythmically intermitting increased excretion of all enzymes mentioned develops. The study confirms the usuability of the DP IV-activity for enzymological investigations of the urine.

Acute Kidney Injury↗