Tagesgeschichte

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Alterations of peripheral blood lymphocyte cyclic AMP and cyclic GMP in untreated patients with hodgkin's disease

Cyclic AMP and cyclic GMP are important regulatory agents of lymphocyte functions. Depressed T-lymphocyte functions are frequently associated with Hodgkin's disease and suppressor monocytes have been implicated in the pathogenesis of this defect. In the present study cAMP and cGMP resting levels were measured in lymphocytes from 18 untreated patients with Hodgkin's disease using a sensitive radioimmunoassay. A significant decrease of cAMP (P less than 0.001) and, to a lesser degree, of cGMP (P less than 0.01) was found in monocyte-depleted lymphocyte suspensions from the patients compared to controls. Studies of patient and control lymphocyte subpopulations showed in patients a clear deficit of cAMP in T-depleted lymphocytes, rather than in T cells, with a low cAMP/cGMP molar ratio in both subpopulations. From this data it is clear that factors other than prostaglandin-mediated suppression of monocyte origin are involved in the pathogenesis of the T-lymphocyte depression associated with Hodgkin's disease.     

Influence of calcium and ionophore 23187 on tubular phosphate reabsorption

In previous studies it has been demonstrated that a decline of plasma calcium concentration accounts for the decrease of phosphate reabsorption in thyroparathyroidectomized (TPTX) rats undergoing phosphate loading.Microinfusion studies were performed in TPTX rats in order to discriminate between a systemic effect of calcium an a direct renal effect.Thyroparathyroidectomized animals were infused with a phosphate solution continuously. When plasma calcium concentration fell below 1.30 mmol/l, proximal convoluted tubules were microinfused with a phosphate tracer solution for 42 min. After 18 min a calcium chloride-containing solution was applied superficially (superfused) to the area of the microinfused tubule. This elevation of peritubular calcium concentration led to an immediate increase of phosphate reabsorption up to 12% of the microinfused phosphate load within 24 min.In another series of experiments, the calcium specific ionophore A 23187 — a substance which is known to increase intracellular calcium — was superfused on the microinfused tubule. This resulted again in an increase of fractional phosphate reabsorption of about 15% after 24 min. In contrast, when calcium chloride-free as well as ionophore-free solutions were superfused fractional phosphate reabsorption decreased (7%).From these data we conclude that 1. calcium has a direct renal effect on phosphate reabsorption in the absence of parathyroid hormone and 2. intracellular calcium appears to be a major parameter in the regulation of renal phosphate transport under these conditions.This study was supported by Dr. Legerlotz StiftungParts of this study were presented at the fall meeting of the Nephrologische Gesellschaft in Bonn, 1977 and at the spring meeting of the Deutsche Physiologische Gesellschaft in Göttingen, 1978     

Modulating parameters of excitability during and after transcranial direct current stimulation of the human motor cortex

Weak transcranial direct current stimulation (tDCS) of the human motor cortex results in excitability shifts which occur during and after stimulation. These excitability shifts are polarity-specific with anodal tDCS enhancing excitability, and cathodal reducing it. To explore the origin of this excitability modulation in more detail, we measured the input–output curve and motor thresholds as global parameters of cortico-spinal excitability, and determined intracortical inhibition and facilitation, as well as facilitatory indirect wave (I-wave) interactions. Measurements were performed during short-term tDCS, which elicits no after-effects, and during other tDCS protocols which do elicit short- and long-lasting after-effects. Resting and active motor thresholds remained stable during and after tDCS. The slope of the input–output curve was increased by anodal tDCS and decreased by cathodal tDCS. Anodal tDCS of the primary motor cortex reduced intracortical inhibition and enhanced facilitation after tDCS but not during tDCS. Cathodal tDCS reduced facilitation during, and additionally increased inhibition after its administration. During tDCS, I-wave facilitation was not influenced but, for the after-effects, anodal tDCS increased I-wave facilitation, while cathodal tDCS had only minor effects. These results suggest that the effect of tDCS on cortico-spinal excitability during a short period of stimulation (which does not induce after-effects) primarily depends on subthreshold resting membrane potential changes, which are able to modulate the input-output curve, but not motor thresholds. In contrast, the after-effects of tDCS are due to shifts in intracortical inhibition and facilitation, and at least partly also to facilitatory I-wave interaction, which is controlled by synaptic activity.     

Buchbesprechungen

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The ophthalmic artery and its branches,measurements and clinical importance

Summary Seventy-one Caucasian orbits (36 right, 35 left) were studied by dissection. The diameter of the ophthalmic a. (2 mm from the origin) was 1.54 ± 0.04 mm (male) and 1.31 ± 0.05 mm (female). In individual cases, there were no significant differences in vessel diameter between the right and left sides but, differences in vessel diameter between males and females were more commonly observed in the arteries which leave the orbit (extraorbital group), the individual vessels having a larger diameter in males. The incidence of the ophthalmic a. passing in the orbit medially under the optic n. was 18.6%. The lacrimal a. was observed to arise from the ophthalmic a. in only 82.5% of the cases examined, 15.9% of the cases showed the origin to be at the anastomotic branch of the middle meningealThis article is dedicated to Pr Dr Hoepke on occasion of his 100th birthday     

The measurements of the clivus, the foramina on the external base of the skull and the superior vertebrae

Anatomical measurements are made on the clivus and the upper cervical column. These values are important for transoral, transpalatinal approaches to the clivus and to atlas and axis. The mean-values of the length of clivus in adults were 45 mm on the internal cranial base, on the external the length between the basion and the vomer was estimated with 27.9 mm, the tuberculum pharyngeum is situated on our material 11.2 mm rostral of the basion. The anterior part of clivus in the external cranial base has a width of 22.5 mm, the posterior part has one of 42.8 mm. Included are measurements of the hypoglossal canal and measurements of foramen lacerum externum. The postnasal enlargement of the most portals of the cranial base is given in Fig. 5. The occipital condyles are 22.9 mm in length, the angle between the condyles was 51.4 degrees. The thickness of clivus was 18.3 mm in a level 28 mm rostral of basion and 9.3, 11 mm rostral of basion. Given are also the thickness of substantia corticalis of clivus and the area of posterior wall of sphenoid sinus. Measured are also the distances between dens axis and anterior arch of atlas and basion. The height of anterior arch was found larger than by other researchers. Included are length and width values of the upper cervical column and the insertion areas of the longus capitis and rectus capitis anterior muscles.