Enzyme activities in the rabbit cornea during immunogenic keratitis

In rabbits inflammation of the cornea was induced by intrastromal injection of horse serum. Between 2 and 4 weeks after injection, infiltration of the cornea with leukocytes and neovascularization could be observed. During this period, the rabbits were killed and their corneas analyzed for protein, alkaline phosphatase, acid phosphatase,N-acetyl--D-glucosaminidase, and lactate dehydrogenase. The enzyme activities in the inflamed corneal stroma reflect the high lysosomal activity, which probably originates from the leukocytes. The enzyme activities in the epithelium indicate that the tissue is abnormal and undergoing repair processes.     

Optic nerve atrophy and CT scanning: the target sign

Three patients are described who demonstrate the "target-sign" of optic nerve atrophy on CT scanning. This sign is produced by the centrally located atrophic optic nerve surrounded by a patulous perioptic subarachnoid space. An explanation for this phenomenon is proposed.     

The "Ring" method: a semi-empirical method to calculate dose distributions of irregularly shaped photon beams

The "Ring" method provides a fast dose calculation and isodose presentation for photon beams with blocks. The method takes into account the change in scatter due to the blocks at each calculation point. Firstly, the dose in a point is calculated assuming that no blocks are present. Secondly, the scatter reduction caused by the blocks is calculated and subtracted. To determine the scatter reduction the irradiated surface is divided in concentric rings around a point at the surface at the intersection with a ray line between focus and calculation point. The scatter reduction caused by blocks for each ring is calculated. The effect of scatter for rings with an outer radius greater than 15 cm where the scatter contribution is less than 1.0% is neglected. Results of the method for 4 MV photons using eight rings are presented. Comparison of dose measurements with calculations in an arrow-shaped photon field showed maximum deviations of 4.0%, using the IRREG program of Cunningham, 6.5% using the BLKINP program of Schlegel, which is based on Clarkson's method, 5.0% using the method of Wrede and 2.2% using the "Ring" method. Contrary to the first two calculation programs, the programs using the last two calculation methods provide isodose lines dose values at points.     

173. Gibt es bakteriologische Diagnosekriterien des perforierten Gastroduodenalulcus?

Zusammenfassung Die entscheidenden Kriterien für die Prognose einer Ulcusperforation sind Alter, die Zeitdauer bis zur operativen Versorgung sowie das Geschlecht der Patienten. In der eigenen Klinik wurden von 1974 bis 1985 85 Patienten versorgt. Dies erfolgte mit der Tendenz zum kleinstmöglichen Eingriff. Eine synchrone definitive Operation der jeweiligen Ulcuskrankheit war die Ausnahme. In einer seit 1981 durchgeführten prospektiven Studie wurden Keimart, Keimzahl, Zellzahl, pH-Wert sowie der Nachweis von Toxinen untersucht. Es ergab sich keine Relation zur Letalität des Einzelfalles.     

Anthraquinones, Anthrones and Dianthrones in Callus Cultures of Rhamnus frangula and Rhamnus purshiana

Tissue cultures initiated from the cambial zone in branches of RHAMNUS FRANGULA L. and RHAMNUS PURSHIANA DC were grown on modified Murashige and Skoog medium with kinetin and 2,4-D as growth factors. To study the production of the genuine anthraquinone derivatives, the extraction of the fresh calli was performed in such a way that oxidation was prevented. In the fresh callus of RHAMNUS FRANGULA the glycosides of chrysophanoldianthrone and chrysophanolphys-ciondianthrone predominantly occurred, whereas in the freeze dried bark of RHAMNUS FRANGULA the glycosides of emodin and emodinanthrone were the main components. Aloe-emodin, which does not occur in the intact bark material of RHAMNUS FRANGULA, was proved to be present in the callus culture. In the fresh callus of RHAMNUS PURSHIANA the glycosides of chrysophanolanthrone and physcionanthrone dominated, while in the freeze dried bark of RHAMNUS PURSHIANA the glycosides of emodin, emodinanthrone and aloe-emodin were predominantly present. The total yields of the glycosidic bound aglycones produced in both cultures were approximately one third of the yields produced in the bark of the two intact species from which the cultures originated.     

Prolactin concentration in plasma and susceptibility to mammary tumors in female rats from different strains treated chronically with estradiol-17β

Summary Prolactin is associated with the development of mammary tumors in rats. The aim of the present study was to evaluate whether strain differences in susceptibility to the development of mammary tumors could be explained by genetic differences in the response of the pituitary to chronic stimulation by estrogens. Prolactin levels were measured in plasma from rats of the Sprague-Dawley, Wistar WAG/Rij and Brown Norway BN/BiRij strains before and at different times after subcutaneous implantation of estradiol-17 in cholesterol/paraffin pellets. In all strains plasma prolactin was elevated from the second week after implantation of the pellet, although there were quantitative differences between the responses. At 32 weeks after implantation of the pellets the plasma level of prolactin in Sprague-Dawley rats was 1247 ± 367 ng NIAMDD prolactin RP-1/ml (mean ± S.E.M), whereas Wistar WAG/Rij and Brown Norway BN/BiRij had plasma prolactin levels of 679 ± 211 and 182 ± 19 ng/ml respectively. Between 52 and 104 weeks after implantation these values rose to 4016 ± 1116, 5004 ± 1053 and 808 ± 129 ng/ml respectively. The plasma concentration of prolactin of rats in this age group was strongly associated with the occurrence of pituitary adenomas in all three strains. In untreated rats, the concentration of prolactin in the plasma increased with age to only 200–400 ng/ml at 12–24 months of age but no significant differences were observed between the three rat strains. It is concluded that observed differences in spontaneous and estrogen-mediated mammary tumor development in these rat strains cannot be explained by genetic differences in the plasma concentration of prolactin. The development of malignant mammary tumors after estrogen treatment appears to be associated with the extent of the increase in plasma prolactin induced by the estrogen.     

Inhibitory dopamine receptors on sympathetic neurons innervating the cardiovascular system of the pithed rat

Summary Additional experimental evidence was obtained for an inhibitory function of prejunctional ₂-adrenoceptors and/or dopamine receptors located on noradrenergic neurons innervating the heart and resistance vessels of the pithed normotensive rat. Mixed ₂-adrenoceptor receptor agonists, differing in selectivity towards either receptor type, i.e. N,N-di-n-propyldopamine (DPDA), 2-N, N-di-n-propylamino-6, 7-dihydroxy-1,2,3,4-tetrahydronaphthalene (DP-6,7-ADTN), B-HT 920 and B-HT 933 (azepexole) were used.In pithed normotensive rats, DPDA (30 and 100 g/kg/min) dose-dependently inhibited the electrical stimulation-induced increase in diastolic pressure, but did not significantly affect the stimulation-evoked increase in heart rate. The inhibition exerted by DPDA was blocked by haloperidol and sulpiride (0.3 mg/kg of each), but not by yohimbine (1 mg/kg), indicating the involvement of dopamine receptors. In this respect, sulpiride and haloperidol were found approximately equipotent.DP-6,7-ADTN (10 and 30 g/kg/min) impaired both tachycardic and vasoconstrictor responses in a dose-dependent manner. Sulpiride (0.3 mg/kg) only partially restored the DP-6,7-ADTN-depressed stimulation-evoked increase in diastolic pressure, whereas yohimbine (1 mg/kg) alone was without effect. The combination of both antagonists completely prevented the inhibition caused by DP-6,7-ADTN. On the other hand, yohimbine (1 mg/kg), but not sulpiride (0.3 mg/kg), selectively antagonized the DP-6,7-ADTN-induced inhibition of stimulation-evoked tachycardia.B-HT 920 (1, 3 and 10 g/kg/min) very effectively reduced the increase in diastolic pressure and heart rate caused by electrical stimulation. Inhibitory dopamine as well as ₂-adrenoceptors participated in the vascular effects of B-HT 920, whereas ₂-adrenoceptors were only involved in the cardioinhibitory response to this agonist.B-HT 933 (0.6 and 1 mg/kg/min) dose-dependently reduced the stimulation-evoked increase in arterial pressure through selective stimulation of inhibitory ₂-adrenoceptors, dopamine receptors not taking a part.The results confirm and extend the observations that in addition to ₂-adrenoceptors inhibitory dopamine receptors are located on the sympathetic neurons connected with the arterial vasculature of the pithed normotensive rat. The sympathetic nerves innervating the rat heart do not contain inhibitory dopamine receptors; their activity only can be modulated by ₂-adrenoceptor stimulation. In the pithed normotensive rat, activation of prejunctionally located ₂-adrenoceptors more effectively inhibits the sympathetic activity directed to the heart than that to the resistance vessels.     

Interactions between the putative calcium entry promotor Bay k 8644 and pressor responses produced by α-1 and α2-adrenocepter agonists in the pithed normotensive rat

Summary Interactions between the putative calcium entry promotor Bay k 8644 and both -₁ and ₁-adrenocepter mediated increases in diastolic pressure were studied in the pithed normotensive rat. The ₁-adrenocepter mediated pressor responses elicited by B-HT920, TL-99, DP-6,7-ADTN and B-HT958 were potentiated by Bay k 8644, reflected by a leftward shift and an increase in the maximum of the log dose-pressor respinse curves. The -₁-adrenocepter effects elicited by cirazoline, methoxamine, (–)-amidephrine, St 587, (–)-phenylephrine and Sgd 101/75 were less enhanced by Bay k 8644. Only a leftward shift of the dose-response curves was observed, which was most pronounced for (–)-phenylephrine and Sgd 101/75. The -₁ and ₂-adrenocepter pressor components of (–)-noradrenaline were similarly distinguished by Bay k 8644 as observed for the selective -₁ or ₂-adrenocepter agonists.Effects of Bay k 8644 on the increase in diastolic pressure mediated by B-HT 920, St 587 and cirazoline were also studied after pretreatment with the calcium entry blocker nifedipine. After additional pretreatment with nifedipine the potentiation by Bay k 8644 observed for B-HT 920 and St 587 was more pronounced. The presence of nifedipine had no effect on the interaction between Bay k 8644 and cirazoline.It is concluded that Bay k 8644 behaves as a mirror image of nifedipine. The observation that Bay k 8644 enhances ₂-adrenocepter mediated pressor effects more effectively than ₁-adrenocepter increases in diastolic pressure is in accordance with the hypothesis of the more pronounced calcium dependency of ₂-adrenocepter mediated pressor responses. The data obtained for ceptor mediated pressor responses. The data obtained for St 587 and (–)-phenylephrine are in apparent contradiction to the finding that the pressor responses to the former drug are more markedly inhibited by calcium entry blockade than those of the latter. It is suggested that St 587 employs calcium channels which are already maximally modulated and that (–)-phenylephrine makes use of calcium channels which are in a rather inactive state. The hypothesis is put forward that the intrinsic activity of ₂-adrenocepter agonists reflects their ability to bring calcium channels in an active state.