Über das bradykininbildende Prinzip des Schlangengiftes

Summary 1. The bradykinin releasing principle of the venom of Bothrops jararaca and of Crotalus atrox is partly dialysable through cellophane. With Crotalus venom about 10% of the total activity are found in the dialysate.2. The dialysates are free of the proteolytic and coagulating (Bothrops) as well as of the tryptic principle of the venoms as measured by the hydrolysis of benzoyl-argininamid. Beside the bradykinin releasing principle they contain an esteratic activity, which splits the methylester of benzoylarginin.3. It is concluded from the results that the bradykinin releasing principle may be identical with the esteratic principle but not with the proteolytic and tryptic nor with the fibrinogen coagulating principle. On the other hand it may belong to the group of Kontaktstoffe which like agar, inulin, starch and the dextranes, release anaphylatoxin when they get into contact with serumproteins.4. Rabbits are about 8 times more sensitive than cats against the bloodpressure lowering action of bradykinin.5. The question is discussed whether the snake venoms contain only one bradykinin releasing factor which is dialysable and of low molecular weight, or whether there are different factors, some of which have a high molecular weight and are therefore not dialysable.

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Mit 7 Textabbildungen

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Herrn Professor Dr. Paul Wels zum 70. Geburtstag gewidmet.

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Die Arbeit wurde mit finanzieller Unterstützung der U.S. Department of the Army, European Research Office, durchgeführt.Eine kurze Mitteilung erfolgte in den Naturwissenschaften (Contzen, Holtz u. Raudonat 1959).     

Our experience with perfluorohexyloctane (F6H8) as a temporary endotamponade in vitreoretinal surgery

PURPOSE: To evaluate the use of F6H8 as a temporary endotamponade for complicated and special cases of retinal detachment instead of silicone oil. METHODS: We have used F6H8 with 14 patients since February 1999. Eight suffered from rhegmatogenous retinal detachment (RRD) with multiple tears located inferiorly. Three presented inferior traction retinal detachment (TRD) under silicone oil, two suffered from ocular trauma with inferior TRD, and one had idiopathic macular hole. The substance was introduced into the eye after pars plana vitrectomy and membrane peeling if needed, and we tried to introduce as much as possible. RESULTS: With F6H8 the retina was easily reattached in all cases, like with perfluorocarbon liquids. The postoperative view was very good. F6H8 was removed in all cases after 3-8 weeks. Anatomical success was achieved in 12 out of 14 eyes. Two eyes presented severe PVR. F6H8 entered the anterior chamber in 4 cases, but no corneal complications occurred. In one case there was a marked IOP rise due to an anterior block, treated with superior iridotomy. In two cases retinal detachment (RD) occurred in the upper part and was treated with additional surgery, F6H8 removal and silicone oil injection. CONCLUSIONS: F6H8 seems to be a promising tamponade agent for special cases of RD.     

Detection of inducible nitric oxide synthase and vascular endothelial growth factor in choroidal neovascular membranes

Vascular endothelial growth factor (VEGF) is among the cytokines which have been implicated in the pathogenesis of choroidal neovascularization secondary to age-related macular degeneration (ARMD). There is, however, evidence that intercellular signaling molecules, such as nitric oxide (NO), are involved in this process. NO is synthesized via the inducible isoform of NO synthase (iNOS), which is expressed after induction by cytokines. In the current study, we investigated whether VEGF and iNOS are coexpressed in choroidal neovascular membranes (n = 7) from patients with ARMD. Immunohistochemistry was performed on cryosections with anti-iNOS and anti-VEGF. Moderate to intense immunostaining for iNOS and VEGF was observed in retinal pigment epithelial cells, macrophages, and in spatial relation to vessel walls. As scored by light microscopy, we found a significant correlation between immunoreactivity for VEGF and iNOS (p < 0.0341) in vascular endothelial cells. Our study supports a significant role for iNOS in the pathogenesis of neovascularization and membrane growth in ARMD. Moreover, our findings suggest a possible relationship between NO and VEGF in the regulation of pathologic angiogenesis in this disease.     

Morphology of the murine optic nerve

PURPOSE: To study the morphology of the murine optic nerve (ON). METHODS: Eyes of C57/Bl6 and BalbC mice were studied by light and electron microscopy. Microvascular castings of the ON region were prepared by transcardial injection of liquid plastic and studied with a scanning electron microscope. Immunohistochemistry was performed using antibodies against glial fibrillary acidic protein (GFAP), connexin 43, carbonic anhydrase II, and collagen types I and III. RESULTS: The transition between nonmyelinated and myelinated portion of the ON started approximately 0.6 mm behind the globe. A lamina cribrosa was completely absent. Instead, ON axons passed through a scleral hole that was surrounded by a ring of type III and type I collagen fibers. Instead of connective tissue beams within the nerve, layers of elongated astrocytes traversed the ON. All astrocytes stained for GFAP, but not for carbonic anhydrase II. The arterial supply of the nonmyelinated ON derived from branches of the central retinal artery. None of the capillaries derived from choroidal vessels. CONCLUSIONS: The mouse ON head differs from that of other species, because it lacks a lamina cribrosa and a choroidal vascular supply. Studies in glaucomatous mice might help to identify the importance of the lamina cribrosa and the choroidal vascular supply for optic nerve damage in glaucoma.     

Mitochondrial DNA content affects the fertilizability of human oocytes

Mitochondrial DNA content varies considerably in oocytes, even when collected from the same patient. In the present study, real-time quantitative polymerase chain reaction analysis of 113 unfertilized oocytes obtained from 43 patients revealed an average of 193,000 (range: 20,000 to 598,000) mitochondrial genomes per cell. We compared several groups of oocytes to investigate the relationship between mitochondrial DNA content and fertilizability. The average mitochondrial DNA copy number was significantly lower in cohorts suffering from fertilization failure compared to cohorts with a normal rate of fertilization. In addition, the mitochondrial copy number of oocytes from patients with fertilization failure due to unknown causes was significantly lower than that of oocytes from patients in which IVF failure was due mainly to a severe sperm defect. The lower mtDNA copy number could be due to defective cytoplasmic maturation of oocytes. We conclude that low mitochondrial DNA content, due to inadequate mitochondrial biogenesis or cytoplasmic maturation, may adversely affect oocyte fertilizability.     

Auditive Verarbeitungs- und Wahrnehmungsstörungen Konsensus-Statement der Deutschen Gesellschaft für Phoniatrie und Pädaudiologie

Ohne Zusammenfassung     

LASIK mit superiorem Hinge und Scanning-Spot-Excimerlaserablation zur Korrektur von Myopie und myopem Astigmatismus Einjahresergebnisse einer prospektiven klinischen Studie an 100 Augen

Purpose. Recently laser-in-situ-keratomileusis (LASIK) has been increasingly used to correct refractive errors. The purpose of this investigation was to evaluate the safety, efficacy, predictability, stability and complications using the scanning spot excimer LASIK technology. Patients and methods. The results of 100 consecutive LASIK operations carried out between 2/1998 and 2/1999 on 60 patients (mean age 37 years, range 20–55 years) have been evaluated. The Hansatome? microkeratome with a superior hinge (flap diameter: 9.5 mm) and a scanning spot excimer laser (Technolas C-Lasik 217) were used in all cases. The mean spherical equivalent of the subjective manifest refraction was ?6.96±2.87 diopters (D), the mean sphere was ?6.47±2.71 D and the mean astigmatism was ?0.98±0.94 D. In 6% of the eyes preoperative visual acuity was not better than 20/40. Examinations were performed preoperatively, after 1 and 7 days, after 1, 4 and 12 months. Safety, efficacy, predictability, stability and complications were calculated using the datagraph software (version 1.11). Results. All 100 eyes were examined after 1 day and 1 week, 96 after 1 month, 95 after 4 months and 92 after 1 year. Following 1 year none of the eyes lost 2 or more lines of best corrected visual acuity, 99% were within ±1 line and 1% gained 2 lines (safety index 1.03). In 92% of all eyes an uncorrected visual acuity of ≥0.5 was reached, in 77% ≥0.8 and in 51% ≥1.0 (efficacy index 0.89). For 60 eyes (65.21%) a refractive correction of±0.5 D was necessary, for 82 eyes (89.13%) ±1.0 D and for 91 eyes (98.91%) ±2.0 D. The mean spherical equivalent after 1 year was ?0.15±1.31 D. Between 1 and 12 months a mean regression of ?0.14 D occurred. On the request of the patients, 5 eyes were retreated during the study period for under- or overcorrection. Complications due to the microkeratome did not occur. Corneal infections were not observed, a diffuse lamellar keratitis (DLK) was seen in 12 cases, but all cases healed with no loss of visual acuity. In 7 eyes a slight decentration of the ablation was observed using corneal topography, which in one case caused an increase in glare sensitivity. Conclusions. LASIK with superior hinge and scanning spot excimer photoablation is suitable for the correction of myopia (up to a maximum of ?12 D) and for myopic astigmatism (up to a maximum of ?5 D). The refractive results showed a high stability during the 12-month study period but there is still room for improvement of the predictability.