Vorschläge für die Versorgung von Rückenmarksverletzten

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Prejunctional effects of muscarinic agonists on 3H-acetylcholine release in the rat urinary bladder strip

Summary The inhibitory effects of some muscarinic agonists on tritiated acetylcholine release evoked by field stimulation were investigated in the rat urinary bladder strip. The acetylcholine stores of the preparation were labelled with ³H-choline. Electrical field stimulation caused an outflow of tritium, reflecting the release of ³H-acetylcholine. The release of ³H-acetylcholine was decreased in a concentration-dependent manner by all the agonists tested: oxotremorine, muscarone, muscarine, carbachol and methylfurtrethonium. On the contrary, only muscarine and muscarone enhanced the basal efflux of tritium in a concentration-dependent fashion. Concentration-response curves were determined both at 2 Hz and at 1 Hz by using intermittent administration of the drugs. Maximal depression in release (by 78 – 82%) was observed in experiments at 1 Hz. A similar inhibition was obtained at 2 Hz frequency only when a low concentration of calcium (0.6 mM) in the medium was used. Oxotremorine was the most potent among the tested compounds with the same intrinsic activity as the other drugs. In contrast to the other agonists investigated, oxotremorine showed in about 10-fold greater potency at pre- than at postjunctional muscarine receptors in the rat urinary bladder. This difference might depend either on heterogeneity of muscarine receptors or on different mechanism(s) relating to the transducing properties of receptors at the pre- and postjunctional level. A comparison between the relative prejunctional potencies in the rat urinary bladder and in the guinea pig myenteric plexus (data from the literature) suggests that prejunctional muscarine receptors are similar in these tissues. Furthermore, the findings obtained with a low concentration of calcium in the medium may support the view that intraneuronal availability of calcium plays a significant role in modulating the prejunctional negative feed-back mechanism in the rat urinary bladder.Send offprint requests to Dr. G. D'Agostino at the above address     

Internal urethrotomy]

Internal urethrotomy is the first treatment for all kinds of urethral strictures except meatal stenosis and complete urethral obstruction. After urethrotomy a urethral catheter is left indwelling for up to 3 days if the urine is already sterile. In the case of infection it remains in place for 2 weeks. Long-term results depend mainly on the extent of periurethral fibrosis. The over-all success rate is about 50%. Only in a few cases can a second or third urethrotomy be definitively curative. Further urethrotomies are clearly only a palliative treatment of the stricture, comparable in effect to repeated urethral dilatation.     

Laryngoskopische Befunde bei den Frühformen der Syphilis

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Formation of 6-nitro-norepinephrine from nitric oxide and norepinephrine in the spinal cord and its role in spinal analgesia

Spinally released norepinephrine is thought to produce analgesia in part by stimulating alpha(2)-adrenergic receptors, which in turn leads to nitric oxide synthesis. Also, nitric oxide is known to react with norepinephrine in vivo in the brain to form 6-nitro-norepinephrine, which inhibits neuronal norepinephrine reuptake. In the present study, we tested the hypothesis that formation of 6-nitro-norepinephrine occurs in the spinal cord and that intrathecal administration of 6-nitro-norepinephrine produces analgesia by stimulating norepinephrine release. 6-Nitro-norepinephrine was present in rat spinal cord tissue and microdialysates of the dorsal horn and intrathecal space. Intrathecal norepinephrine injection increased 6-nitro-norepinephrine. 6-Nitro-norepinephrine also stimulated norepinephrine release in dorsal spinal cord in vitro. Intrathecal injection of 6-nitro-norepinephrine produced antinociception and interacted additively with norepinephrine for antinociception. Spinal noradrenergic nerve destruction increased antinociception from intrathecally injected norepinephrine, but decreased antinociception from 6-nitro-norepinephrine.These results suggest a functional interaction between spinal nitric oxide and norepinephrine in analgesia, mediated in part by formation of 6-nitro-norepinephrine. Stimulation of auto-inhibitory alpha(2)-adrenergic receptors at noradrenergic synapses decreases norepinephrine release. Paradoxically, alpha(2)-adrenergic agonist injection increases and alpha(2)-adrenergic antagonist injection decreases norepinephrine release in the spinal cord. 6-Nitro-norepinephrine may be an important regulator of spinal norepinephrine release and could explain the positive feedback on norepinephrine release after activation of spinal alpha(2)-adrenergic receptors.     

Kinetoplast DNA signatures of Trypanosoma cruzi strains obtained directly from infected tissues.

We report here a polymerase chain reaction (PCR)-based DNA profiling technique that permits Trypanosoma cruzi strain characterization by direct study of infected tissues. This is based on application of a recently developed method of DNA fragment identification, called low-stringency single specific primer PCR (LSSP-PCR), to the study of the variable region of kinetoplast DNA (kDNA) minicircles from T. cruzi Thus, we can translate the intraspecific polymorphism in the nucleotide sequence of kDNA minicircles into a specific and highly reproducible kDNA signature. Comparison with the phenogram obtained by DNA fingerprinting analysis of a set of T. cruzi strains showed good qualitative correlation between the degree of divergence of the LSSP-PCR profiles and the genetic distance between the strains. kDNA signatures of heart tissue from acutely or chronically infected animals revealed perfect concordance with the patterns obtained from cultured parasites for the CL and Colombiana strains but not for the Y strain, which is known to be multiclonal. However, the match was perfect for studies with two clones of the Y strain. We take this as evidence that in some multiclonal strains there is heterogeneity among the clones in the degree of tropism for the heart tissue. Finally, we showed that it is possible to obtain a T. cruzi kDNA signature from the heart of a human patient with chronic Chagasic myocardiopathy. kDNA signatures obtained by LSSP-PCR of sequences amplified from infected tissues constitute a new tool to study the molecular epidemiology of Chagas' disease.     

Trypanosomicidal kaurane diterpenes from Wedelia paludosa

The diterpenes ent-kaur-16-en-19-oic acid, ent-kaur-9(11),16(17)-dien-19-oic acid and 3 alpha-angeloiloxy-ent-kaur-16-en-19-oic acid were identified as trypanosomicidal compounds of the ethanolic extract from the aerial parts of Wedelia paludosa D.C. (Asteraceae), showing activity up to the lowest dose of 0.68 mg/mL in the in vitro assay against trypomastigotes of T. cruzi, the causative agent of Chagas' disease (American trypanosomiasis). The other isolates, friedelan-3 beta-ol, ent-kaur-16 alpha-ol-19-oic acid, beta-amyrin acetate and (22-E)-stigmasta-5,22-dien-3 beta-ol, were inactive. This is the first report on the trypanosomicidal activity of ent-kaur-9(11),16(17)-dien-19-oic acid and 3 alpha-angeloiloxy-ent-kaur-16-en-19-oic acids; this effect was already known for ent-kaur-16-en-19-oic acid.     

Conservative surgery for Stage I ovarian carcinoma in women of childbearing age

Objective To assess the results of a policy of tailored conservative surgical management for young women with stage I ovarian carcinomas.
Design Retrospective study.
Participants Ninety-nine women aged 40 years or younger who underwent either primary surgery in our department or were referred after primary surgery performed elsewhere.
Methods Of the 99 women in our study, 56 underwent fertility-sparing surgery and 43 more radical surgery. Minimal requirements for conservative management were adequate staging and complete information about the therapeutic options. Factors important in the choice of the treatment were, age, wish to preserve fertility, histologic type and grade, and the stage of the tumour.
Results Conservative treatment was conducted in 84% of nulliparous and in 33% of parous women; 62% of grade 1 tumours, 48% of grade 2, and 50% of grade 3 were treated conservatively. With a median follow up of seven years, we observed five recurrences (9%) of carcinoma in women treated conservatively and five (12%) in those treated more radically. Two women (one in each treatment arm) were saved after recurrence. Two recurrences after conservative surgery involved the residual ovary (3.6%). Two women developed borderline tumour in the contralateral ovary and both were treated by surgery.
Conclusion After adequate staging and accurate information is given to the patient, conservative treatment may be safe in some women with early ovarian cancer. The risk of recurrence in the contralateral ovary is low. Conservative surgery may be also considered in some Stage I grade 3 tumours and in some women with stage IC tumours.     

An improved technique for the extraction of stochastic parameters from stabilograms

An improved characterization of the dynamics of postural sway can provide a better understanding about the functional organization of the postural control system as well as a more robust tool for postural pattern recognition. To this aim, a novel parameterization was applied to the stabilogram diffusion analysis formerly proposed by Collins and De Luca [Collins JJ, De Luca CJ. Open-loop and closed-loop control of posture: a random-walk analysis of center-of-pressure trajectories. Exp Brain Res 1993;95:308–18] that considered the act of maintaining posture as a stochastic process. The main purpose of the present technique was to overcome some drawbacks of the model presented by Collins and De Luca that may restrain its potential application in clinical practice. The approach uses a unique non-linear model to describe the center of pressure (COP) dynamics that reduces the number of parameters and decreases their intra-subject variability; consequently, fewer trials are required to perform reliable estimates of stochastic parameters and this is of particular importance for subjects that cannot afford many repeated measurements because of age or pathology. Four new statistical mechanics parameters (NSMP) were computed on the log–log stabilogram diffusion plots and their estimates were compared in terms of reliability and sensitivity to the visual conditions with: (1) a minimal set of four summary statistic scores (SSS); and (2) the six statistical mechanics parameters (SMP) proposed by Collins and De Luca. All four NSMP showed at least a fair-to-good reliability (intraclass correlation coefficient, ICC>0.49) while SMP (ICC>0.20) showed some poor reliability. A better overall reliability was also observed with respect to SSS. Moreover, only NSMP had a similar score for eyes open and eyes closed conditions. Three out of four NSMP were also significantly sensitive to eyes open or closed conditions (P<0.001) while only three out of six SMP were sensitive to operating conditions (P<0.01).