Examination of possible renal origin of the humoral factor responsible for saline diuresis in the dog

Summary The hypothesis of renal origin of the humoral factor responsible for the natriuresis which follows saline infusion in the dog was tested in a cross-circulation model especially designed for the purpose. Renal venous blood of saline loaded donor dogs was pumped directly into the system perfusing the right (assay) kidney of oliguric recipient animals. In control and recovery periods, recipients own renal venous blood was substituted for the blood of saline-infused donors.Sodium excretion increased slightly from the control value of 2.8±1.2 (S.D.) to 4.7±3.5 Eq/min (68 per cent increase,p<0.05), but only slight recovery toward control rate was noted within 25 min of cessation of cross-circulation. Simultaneously, filtered sodium decreased slightly from 2.8±1.15 (S.D.) to 2.7±1.10 mEq/min. Glomerular filtration rate (C _CR) and effective renal plasma flow (C _PAH) decreased gradually during the experiment. Urine flow,U/P _osm, hematocrit, and perfusion pressure of the assay kidney showed only minor changes.Since the slight increase in sodium excretion during cross-circulation constituted but a small fraction of natriuresis observed in saline-loaded donors, it was concluded that the results are incompatible with the release from the kidney of saline-infused animals of a potent natriuretic factor.This study was supported by American Heart Association Grant 66630.     

Block of non-L-, non-N-type Ca2+ channels in rat insulinoma RINm5F cells by ω-agatoxin IVA and ω-conotoxin MVIIC

The high-voltage-activated (HVA) Ba²⁺ currents of rat insulinoma RINm5F cells insensitive to dihydropyridines (DHP) and -conotoxin GVIA (-CTx-GVIA) have been studied for their sensitivity to -agatoxin-IVA (-Aga-IVA) and -CTx-MVIIC. Blockade of HVA currents by -Aga-IVA was partial (mean 24%), reversible and saturated around 350 nM (half block 60 nM). Blockade by -CTx-MVIIC was more potent (mean 45%), partly irreversible and saturated above 3 M. The effects of both toxins were additive with that of nifedipine (5 M) and were more pronounced at positive potentials. -Aga-IVA action was additive with that of -CTx-GVIA (3 M) but was largely prevented by cell pre-treatment with -CTx-MVIIC (3 M). In contrast, -CTx-MVIIC block was attenuated by -CTx-GVIA treatment ( 15%), suggesting that -CTx-MVIIC blocks the N-type ( 15%) and the non-L-, non-N-type channel sensitive to -Aga-IVA ( 30%). Consistent with this, cells deprived of most non-L-type channels by pre-incubation with -CTx-GVIA and -CTx-MVIIC exhibited predominant L-type currents that activated at more negative potentials than in normal cells (-30 mV in 5 mM Ba²⁺) and were effectively depressed by nifedipine (maximal block of 95% from -30mV to +40 mV). Our results suggest that, besides L- and N-type channels, insulin-secreting RINm5F cells possess also a non-L-, non-N-type channel that contributes significantly to the total current ( 30%). Although the pharmacology of this channel is similar to Q-type and ₁ class A channels, its range of activation (>-20 mV) and its slow inactivation time course resemble more that of N- and P-type channels. The channel is therefore referred to as Q-like.     

Atrial natriuresis under the condition of a constant renal perfusion pressure

An experimental elevation of left atrial pressure (eLAP ) by means of a reversible mitral stenosis is accompanied with an increase in sodium excretion (UNa—) and arterial blood pressure (by about 20 mm Hg, 2.7 kPa), and by a decrease in plasma renin activity.It is well established that an increase in renal perfusion pressure (Pren) can augment UNa—. Therefore the present study was undertaken to examine whether the eLAP -induced natriuresis was caused by the increased Pren. — Four female beagle dogs were kept under controlled environmental conditions. They received asodium rich diet (14.5 mmol/Na/kg/d). The dogs were chronically instrumented: purse string around the mitral annulus, catheter in the left atrium, carotid loop, pneumatic cuff above the renal arteries, pressure transducer below the renal arteries. Pren was kept constant by means of a digital servofeedback control circuit. The dogs served as their own controls (13 experiments without and 15 experiments with a controlled renal perfusion pressure were performed).After eLAP(+1.0 kPa), UNa— rose from 4.1±2.6 to 10.3±3.9 mol Na/min/kg. If Pren was kept constant, the corresponding values were 4.2±2.8 and 9.3±2.9 mol/min/kg. These data clearly indicate that the atrial natriuresis is not mediated by an augmentation of renal perfusion pressure. Therefore these results support the hypothesis that atrial natriuresis probably is due to an eLAP-induced suppression of the renin-angiotensin-system or other natriuretic mechanisms.Abbreviations ADP 3×20 min After distension period - AN Atrial natriuresis - bw kg Body weight - CP 3×20 min Control period - DP 3×20 min Distension period - eLAP kPa Experimental increase of left atrial pressure (during all DP's about +1.0 kPa) - HR l/min Heart rate - LAP kPa Left atrial pressure - n ₁ Number of dogs used - n ₂ Number of experiments (1 expt/day) - n ₃ Number of collection periods (urine) or number of samples (HR) - Part kPa Mean systemic arterial blood pressure (carotid artery) - Pren kPa Mean renal perfusion pressure (aorta, below the renal arteries) - UCI— mol/min/kg Chloride excretion - UK— mol/min/kg Potassium excretion - UNa— mol/min/kg Sodium excretion - Uosm— osm/min/kg Osmolar excretion - — l/min/kg Urine volume Preliminary parts of this work have been presented in Kiel (Spring meeting of the Deutsche Physiologische Gesellschaft, March 1979) and in Stockholm, Sweden (III. European Colloquium on Renal Physiology, June 1979).     

Determination of glomerular intracapillary and transcapillary pressure gradients from sieving data

Summary Determination of glomerular intracapillary and transcapillary pressure gradients from sieving data. A biomathematical model is described to calculate the intracapillary and transcapillary glomerular pressure gradients from the sieving coefficients (: fractional clearances/GFR) of macromolecules such as polyvinylpyrrolidone (PVP). Two differential equations have been developed. The first one calculates local values for GFR in terms of local values forPGC (intracapillary hydrostatic pressure) and (oncotic pressure). The second equation calculates the clearance of PVP equimolecular fractions, the sieving equations previously described (24) being used to derive the concentrations of PVP in the filtrate (c ₂). Two variants of the second equation have been considered, assuming the filtrate in contact with the membrane either well stirred or unstirred (constantc ₂ and localc ₂ gradient models respectively).Computer simulations have been used to illustrate how the sieving curve is modified when the five parameters on which depends the shape of the curve are changed one by one. The sieving curve relates toa _s (hydrodynamically equivalent molecular radius). The determining parameters are: , the mean effective glomerular filtration pressure, , the slope of the intracapillary pressure,FF, the filtration fraction,Cp ₀, the protein concentration in arterial plasma andr, the pore radius which is the only structural parameter involved when one assumes the glomerular membrane crossed by cylindrical pores of uniform size and length.The shape of the sieving curve is modified significantly enough by changing ,FF andr within reasonable limits, to make it possible to derive andr from experimental sieving data for macromolecules such as PVP or dextrans.     

Usefulness of low-priming-volume cardiopulmonary bypass circuits and dilutional ultrafiltration in neonatal open-heart surgery

In neonate open-heart surgery, cardiopulmonary bypass (CPB) with extreme hemodilution induces an increased capillary permeability and accumulation of extravascular fluid, resulting in organ dysfunction. We evaluated the effects of a reduced priming volume for CPB and dilutional ultrafiltration (DUF) during neonatal open-heart surgery. Nineteen consecutive neonates with complete transposition of the great arteries who underwent an arterial switch operation were retrospectively assigned into two groups: the high-priming-volume circuit group (group A, n = 9) and the low-priming-volume circuit group (group B, n = 10). Patients in group B underwent surgery with a miniaturized CPB circuit and using the DUF technique. The priming volume of group B was nearly two-thirds that of group A. The water balance value after CPB and surgery was significantly lower in group B (–126 ± 118ml, –116 ± 116ml) than in group A (88 ± 218ml, 83 ± 165ml). Systolic blood pressure just after CPB was higher in group B (67.9 ± 9.1mmHg) than in group A (55.4 ± 10.3mmHg). Postoperative ventilatory support was shorter in group B (45 ± 19h) than in group A (68 ± 27h). In neonatal cardiac surgery, low-priming-volume CPB circuits and DUF improve the water balance during surgery and may attenuate any inflammatory reaction, which would help preserve postoperative organ function.     

Myofibril and sarcoplasmic reticulum changes with exercise and growth

Summary The intent of this study was to observe the effects of different treadmill running programs upon selected biochemical properties of soleus muscle from young rats. Young 10 day litter-mates were assigned to endurance (E), sprint (S) and control (C) groups. Each was partitioned into either 21 or 51 day exercising groups and 10 day controls. For C the myofibril ATPase activity at 21 and 51 days were lower than 10 day activity (p0.05). In the 51 day E group ATPase activity (0.378±0.009 mol Pi·mg^–1·min^–1) was greater than at 10 and 21 days (0.307±0.006 and 0.323±0.008 mol Pi·mg^–1·min^–1) (p0.05). No change occurred in the S group from 10 to 21 and 51 days (p0.05). Both the 21 and 51 day S (0.318±0.011 and 0.399±0.010 mol Pi·mg^–1·min^–1) and E (0.323±0.008 and 0.378±0.009 mol Pi·mg^–1·min^–1) groups had higher activity compared to the C group (0.193±0.029 and 0.172±0.031 mol Pi·mg^–1·min^–1) (p0.05). Maturation (10–51 day) resulted in a lowered sarcoplasmic reticulum (SR) yield and Ca²⁺ binding (p0.05) while Ca²⁺ uptake ability did not change (p0.05). SR yield, Ca²⁺ binding and uptake were not altered with S training (p0.05). The E training resulted in greater Ca²⁺ uptake at 51 days compared to C and S (p0.05), with no change in Ca²⁺ binding (p0.05). The data suggest that E training alters the normal development pattern of young rat soleus muscle.Supported by grants A-6449 and A-0425 from the Natural Sciences and Engineering Research Council of Canada     

Effect of posture on arterial baroreflex control of heart rate in humans

Summary Altered baroreflex function may contribute to the cardiovascular changes associated with weightlessness. Since central blood volume (CBV) increases during simulated weightlessness, we have examined the possibility that acute changes in CBV may modify baroreceptor function. We used graded head-up tilt (HUT) and head-down tilt (HDT) to induce changes in CBV, and neck suction to stimulte carotid baroreceptors, in 6 subjects. The increase in pulse interval induced by a negative pressure of 8.2 kPa (62 mm Hg) imposed for 10 s while supine was compared with the increase while tilted for 8 min at ± 15, ± 30 and ± 45. During HDT at 15 the pulse interval over the first 5 cardiac cycles following suction onset was 51 ± (SEM) 18 ms longer (p<0.05), at 30 it was 61±20 ms longer (p<0.05), and at 45 it was 74±35 ms longer (p<0.01), compared with supine. During HUT at 15 the pulse interval was 25±9 ms shorter (p<0.05) than when supine, but was not significantly different at 30 and 45. These responses occurred independently of changes in brachial blood pressure. Attenuation was also observed after 5 min (56±17 ms; <0.05), and after 40 min (25±9 ms; p<0.05) of 60 HUT compared with supine. We conclude that posture does modify arterial baroreflex control of heart rate. If this occurs primarily as a result of a change in CBV, then the acute effect of weightlessness may be an accentuation, not an attenuation, of baroreflex function.M. H. Harrison was a National Research Council postdoctoral research fellow on leave from the Ministry of Defence, UK     

Central venous pressure and plasma arginine vasopressin during water immersion in man

Summary The influence of increased central venous pressure (CVP) on the plasma concentration of arginine vasopressin (pAVP) was examined in 7 healthy males subjected to water immersion (WI) up to the neck following overnight food- and fluid restriction. During WI the subject sat upright in a pool (water temperature=35.0 C) for 6 h. In control experiments the subject assumed the same position outside the pool wearing a water perfused garment (water temperature=34.6 C). CVP increased markedly during WI and after 20 min of immersion it attained a level which was significantly higher than the control value (10.9±1.5 (mean ± SE) vs. 2.2±1.3 mm Hg, p<0.01). This increase was sustained throughout the 6 h WI period. Simultaneously, after 20 min pAVP during WI was significantly lower than control values (1.8±0.3 vs. 2.2±0.3 pg·ml^–1, p<0.05) and sustained throughout WI. Systolic arterial pressure increased significantly by 7–10 mm Hg (p<0.05) after 2 h of WI, while diastolic arterial pressure was unchanged. Heart rate was decreased by 10 bpm throughout immersion. There was no change in plasma osmolality when comparing control with immersion. A pronounced osmotic diuresis, natriuresis and kaliuresis occurred during WI, counteracting an acute significant increase in plasma volume of 6.5±1.9% (P<0.01 within 20 min of immersion). We conclude that an increase in CVP due to WI is accompanied by suppressed pAVP.This investigation was supported by the Danish Space Board, grant nr. 1112-32/83, 1112-33/83 and 1112-19/84     

Renal intracortical blood flow distribution,function and sodium excretion in response to saline loading of anesthetized and unanesthetized dogs

Summary In order to study the effect of anesthesia on the canine response to saline loading, experiments were performed on 10 dogs, first while awake and then during pentobarbital anesthesia. Individual kidney function and intrarenal blood flow response to saline loading (7.5% body weight) were measured in each condition and all data are reported as the average of a single kidney. C_IN is considerably reduced under anesthesia (24.7±3.2 vs. 43.2±3.9 ml/min,P<0.01). A directionally similar reduction of PAH clearance was noted (89±17 vs. 122±13 ml/min). The natriuretic response to saline loading of the dogs reached 290±61 Eq/min while awake, but only 70±27 Eq/min while anesthetized. No measurable increase of C_IN or C_PAH occurred in response to saline loading either in the anesthetized or unanesthetized state. The natriuresis was entirely due to a rise of C_NA/GFR in both circumstances. The change of C_NA/GFR in response to saline load was also appreciably larger while awake (1.24.7% vs. 0.71.8%). Although the fraction of blood flow to the outermost quarter of the kidney was initially the same (31±3 vs. 29±3%) awake or anesthetized, the changes with saline loading were in the opposite direction and the values reached were significantly different (37±3, awake, vs. 27±3%,P<0.05). We conclude that while increased outer cortical blood flow is not necessary for natriuresis, it may occur during sodium loading and may facilitate sodium excretion.Supported by VA Program 3385-01     

Suppression of Adjuvant Arthritis and Synovial Macrophage Inducible Nitric Oxide by N-iminoethyl-L-Ornithine, A Nitric Oxide Synthase Inhibitor

Nitric oxide NO is a pro-inflammatory effector molecule in certain inflammatory diseases, including arthritis. We investigated the production of NO by adjuvant arthritis (AA) synovial macrophages, and studied the effects of a NO synthase inhibitor, N-iminoethyl-L-ornithine (L-NIO). Compared to control rats, rats treated with L-NIO in vivo exhibited significantly lower articular index (p < 0.05), paw volume (p < 0.05), and synovial fluid cell count (p < 0.05). No effect on cutaneous delayed-type hypersensitivity to the disease-initiating antigen was observed. Inducible NO synthase (iNOS) was detected in AA synovial macrophages, and cultured AA synovial macrophage iNOS levels were increased by a factor of 138 ± 17% (p < 0.01) by 1 g/ml LPS in vitro. Constitutive NO production by AA synovial macrophages (43 ± 1 nmol/10⁵ cells/24 h) was significantly inhibited by 10 mM L-NIO in vitro (32 ± 0.5, p<0.01). NO production induced by 1 g/ml LPS (48 ± 2) was also decreased by L-NIO (39 ± 2, p<0.05). In vivo L-NIO treatment also inhibited alveolar macrophage NO production (p < 0.05). The ability of L-NIO to decrease iNOS-mediated synovial macrophage NO production and inhibit the clinical parameters of AA implicate macrophage-derived NO in the pathogenesis of this disease.     

Sodium chloride preference in hypertensive (H) and normotensive (N) rats

Summary Salt consumption was compared in two strains of rats, selected for their disparate proneness (strain H) or resistance (strain N) to Doca-salt hypertension.NaCl intake was similar in H and N rats prior to an following administration of Doca, while their respective blood pressures at the end of this experiment was 178±5 mm Hgvs. 134±3 mm Hg. Thus, disparate responses of the blood pressure to Doca in the two strains cannot be ascribed to differences in salt intake.In another study, salt preference was tested in H and N rats by two-bottle self-selecting technique. Before Doca, saline preference in H rats averaged 60.3±5.8% of total daily fluid consumption,vs 18±4.2% in N rats. Following Doca treatment for 3 weeks the respective values were 96±1.7%vs. 67±6.6%. Thus Doca treatment enhanced salt appetite in both strains, but salt preference remained significantly higher in the H rats.The increased susceptibility to hypertension and the enhanced salt appetite in the H rat, corroborates similar reports in the Okamoto SH rat. In the Brookhaven S rat, however, susceptibility to hypertension is associated with salt avoidance. The conflicting data do not support a unified concept of a genetically determined link between salt appetite and proneness to hypertension.This work was supported in part by a grant from the joint research fund of the Hebrew University-Hadassah Medical School, Jerusalem, and by a grant in aid from Merck Sharpe and Dohme, Research Laboratories.     

Adaptation and habituation of the vestibulo-ocular reflex in intact and inferior olive-lesioned rats

Summary The gain of the vestibulo-ocular reflex (VOR) of intact pigmented rats was adaptively modified by training protocols that created a visual-vestibular conflict. For training, head restrained animals were oscillated on a turntable in front of an optokinetic pattern projected onto a cylindrical wall. The optokinetic pattern either moved the same amplitude with the animal (in-phase: 0.05 Hz ± 20°/s) or opposite in direction (out-of-phase: turntable and pattern 0.05 Hz ± 10°/s each). VOR responses were tested in darkness before and after each 8 min training period for a duration of 40 min. During out-of-phase training the gain of compensatory eye movements measured in light was close to 2 from the beginning on and the VOR tested in darkness increased in gain progressively from 0.48 (±0.12) to 0.9 (±0.3; P < 0.05) in 5 out of 7 rats. Two rats did not adapt their VOR gain. Phase values decreased slightly by about 10°. During in-phase stimulation compensatory eye movements were almost completely suppressed (gain close to 0) from the beginning on and the VOR tested in darkness decreased gradually in gain from 0.62 (±0.17) to 0.13 (±0.1; P<0.001) in all 6 trained rats. Phase values decreased in parallel from 151° to 119° (P< 0.01). The effectiveness of the in-phase training paradigm in the absence of compensatory eye movements indicates that retinal image slip is the relevant signal for adaptation. In seven rats with histologically verified almost complete inferior olive (IO) lesions (chemically induced at least 45 days prior to training), out-of-phase and in-phase stimulation evoked compensatory eye movements with gains comparable to those in intact rats. VOR parameters measured in darkness were altered with respect to those of control rats. Gain differed extremely between individuals and phase lag re acceleration was in all IO-lesioned rats larger than in intact rats. The time constant of the VOR in response to table velocity steps was significantly longer (17 s ±4) than in intact rats (11 s ± 3). Training did not alter the gain of the VOR in 5 out of 7 IO-lesioned rats. One rat increased its gain during out-of-phase training in the first, but not during a second training session (and not during in-phase training) and another rat decreased its gain during in-phase training (but not during out-of-phase training). These changes in VOR gain might have occurred by chance rather than by learning. The absence of adaptation in IO-lesioned rats can be explained either by the absence of climbing fiber mediated slip signals in the cerebellar cortex or by lesion-induced secondary changes which result in a long-term reduction of the inhibitory efficacy of Purkinje-cells. In the absence of arousing stimuli VOR responses of intact rats exhibit a strong decrement during table oscillations in darkness. Between trials, with the rat at rest, response magnitude recovered spontaneously. Six out of 8 IO-lesioned rats expressed a very similar modification of their VOR gain. These results indicate that the neural mechanisms responsible for adaptive gain decrease during in-phase training and those responsible for a gain decrease during short-term habituation are different.     

Evidence for Na+/Ca2+ exchange in isolated smooth muscle cells: a fura-2 study

Isolated smooth muscle cells (SMC) from guinea pig taenia coli were employed. Suspension of cells were externally loaded in saline with the fluorescent calcium indicators quin-2/AM or fura-2/AM at 20–40 M or 4 M respectively, resulting in an estimated intracellular concentration of 100–200 M for quin-2 or 10–20 M fura-2 (free acid). On addition of 100 M carbachol or high K _o ⁺ (80 mM) depolarization, fura-2 loaded cells contracted (104±47 m,n=121 rest: 39±13 m,n=59 contracted) identically to control (103±35 m,n=232 rest: 39±16 m,n=89 contracted) cells, whereas quin-2 loaded cells were unresponsive to these protocols and there was no significant length change. The Ca _i ²⁺ of fura-2 loaded cells was 100±18 nM (mean±SD,n=15) and was not significantly different from quin-2 loaded cells 107±26 nM (n=13). Treatment of fura-2 loaded cells with 100 M ouabain saline for 10–60 min progressively elevated the Ca _i ²⁺ to a mean of 266±83 nM (n=15). Reduction of Na _p ⁺ (96% Li⁺ replaced) significantly increased Ca _i ²⁺ to 317±77 nM (n=8). After pretreatment with ouabain (100 M), Na _o ⁺ replacement (Li⁺) increased Ca _i ²⁺ at a significantly faster rate [3.6 nM min^–1 (control) cf. 19.8 nM min^–1 (ouabain)].     

Untersuchungen zur Bedeutung des β1C/1A-Gehaltes im Serum von Patienten mit sog. „lupoider“ Hepatitis

Zusammenfassung 111 Patienten mit chronischentzündlichen Lebererkrankungen, darunter 13 Kranke mit sog. lupoiden Verlaufsformen (12 Frauen und 1 Mann), wurden auf mögliche Zusammenhänge zwischen dem Auftreten und dem Titer antinucleärer Faktoren (ANF) und der _1C/1A-Globulinkonzentration im Serum untersucht. Die Titer der ANF des lupoiden Kollektivs (N=13) lagen zwischen 1:8 und 1:512. Der Mittelwert der _1A-Globulinkonzentration betrug 91,9±26,8 mg/100 ml. Für die negative Kontrollgruppe ohne ANF (N=98) wurde die _1A-Globulinkonzentration im Mittel mit 91,1±29,92 mg/100 ml bestimmt. Bei einem Korrelationskoeffizienten von 0,0916 bot das Verhalten der C3-Komponente somit keinen Hinweis auf eine besondere immunologische Reaktionsweise sog. lupoider Hepatitiden bzw. Cirrhosen.

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Summary 111 patients suffering from chronic-inflammatory liver disease, including 13 individuals with lupoid hepatitis or cirrhosis (12 female, 1 male), were studied for a possible relationship between the occurrence and the titier of antinuclear factors (ANF) and the concentration of the _1C/1A-globulin in the serum. The titers of the ANF in the lupoid group (N=13) varied between 1:8 and 1:512. The mean value of the _1A-globulin was 91.9±26.8 mg/100 ml. For the ANF-negative group (N=98) the mean value of _1A-globulin was determined as 91.1±29.92 mg/100 ml. The calculated correlation coefficient was 0.0916. Thus, using the content of the C3-component of serum as a parameter there was no evidence of a particular immunologic reactivity of patients with lupoid hepatitis resp. cirrhosis.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Skull radiograph measurements of normals and patients with basilar impression; use of Landzert's angle

Summary One hundred normal lateral skull radiographs were studied and those of ten patients with basilar impression attending Kenyatta Hospital, Nairobi. The mean shortest distance of the odontoid tip to McGregor's basal line was 1.2±2.28 mm below the basal line (range 6 mm below to 3 mm above basal line), in normals and 9±2.7 mm (6–14 mm) above basal line in patients. The mean basal angle was 113±7 (102–133) in normals and 122±6 (113–125) in patients. The mean nasion-basion-opisthion angle was 162±4 (154–169) in normals and 178±5 (173–185) in patients. The mean total length of clivus was 48±3.7 mm (43–56 mm) in normals and 44±6.6 (36–48 mm) in patients group. The mean median diameter of the foramen magnum was 39±5 mm (30–48 mm), atlas 21±3 mm (18–25 mm) axis 18±3 mm (14–23 mm), third cervical vertebra 16±2 mm (13–22 mm) in normals and in patients: 39±4 mm (36–45 mm), atlas 23±6 (l5–30 mm) axis 19±4 mm (16–25 mm), third cervical vertebra 16±3 (14–20). There was a significant difference in the position of the odontoid tip and the nasion-basion-opisthion angle between the normal and patient groups. All the other parameters measured in this work did not differ significantly between the two groups.

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Etude anatomo-radiologique de crânes normaux et de crânes pathologiques avec impression basilaire; utilisation de l'angle de Landzert

Résumé Cent crânes normaux ont été étudiés sur des radiographies de profil ainsi que dix crânes pathologiques présentant des impressions basilaires chez des patients traités à l'HÔpital Kenyatta de Nairobi. La plus courte distance moyenne entre le sommet de l'odontoÏde et la ligne basale de McGregor a été de 1,2±2,28 mm au-dessous de la ligne basale (extrÊmes étendues de 6 mm au-dessous à 3 mm au-dessus de la ligne basale), chez les sujets normaux et de 9±2,7 mm (6–14 mm) au-dessus de la ligne basale chez les sujets pathologiques. L'angle basai moyen était de 113±7 (102–133) chez les sujets normaux et 122±6 (113–125) chez les sujets pathologiques. L'angle moyen nasion-basion-opisthion était de 162±4 (154–169) chez les sujets normaux et 178±5 (173–185) chez les sujets pathologiques. La longueur moyenne totale du clivus était de 48±3,7 mm (43–56 mm) chez les sujets normaux et 44±6,6 (36–48 mm) chez les sujets pathologiques. Le diamètre moyen du foramen magnum était de 39±5 mm (30–48 mm), celui du foramen vertébral de l'atlas était de 21±3 mm (18 à 25 mm), celui de l'axis (18±3 mm (14–23 mm), celui de la troisième vertèbre cervicale: 16±3 mm (13–22 mm) chez les sujets normaux; chez les sujets pathologiques les chiffres étaient les suivants: foramen magnum 39±4 mm (39–45 mm), atlas 23±6 (15–30 mm), axis 19±4 mm (16–25 mm), troisième vertèbre cervicale 16±3 mm (14–20 mm). Il existe une différence significative dans la position du sommet de l'odontoÏde et la valeur de l'angle nasion-basion-opisthion entre les deux groupes. Aucun des autres paramètres mesurés dans ce travail ne présentait de différence significative entre les deux groupes.

     

Effects of sustained intrathoracic vascular distension on body fluid distribution and renal excretion in man

Summary Intrathoracic blood volume was increased by prolonged immersion in thermo-indifferent (34 C) water. Urinary excretion patterns of free water and electrolytes during immersion were compared with those for an identical period of the previous day when the subjects were performing routine activity. Plasma volume changes during immersion were compared with the concomitant urine volume which under these conditions can be equated with total fluid loss. The nature of the immersion diuresis depended on the state of hydration. Normally hydrated subjects showed a rise in free water clearance whereas a hydropenic group increased urine volume by an augmentation of osmolar clearance. Sodium excretion during immersion rose from 118±48 (SD) to 180±51.7 (SD) eq./h×kg in normally hydrated subjects (p>0.05) and from 66.8±22.5 (SD) to 152±43.3 (SD) eq./h×kg (p<0.01) in the hydropenic group.Immersion led to plasma volume reduction in all cases. Plasma volume reduction constituted a much greater percentage of the urine volume in hydropenic subjects (98.8±35.4 (SD)%) than in the normally hydrated ones (19.3±8.56 (SD)%). It is concluded that engorgement of the intrathoracic volume-sensitive vascular areas may not only lead to increased fluid elimination by the kidney but at the same time to a shift of fluid from plasma into the interstitial space. Both effects serve the homeostatic control of blood volume.This study was supported by Contract F 61052-68-C-0069 of the USAF School of Aerospace Medicine, European Office of Aerospace Research (OAR), U.S. Air Force, and a Grant from the Deutsche Ibero-Amerika Stiftung, Hamburg, Germany.     

Erhöhtes atriales natriuretisches Peptid (ANP) bei essentieller Hypertonie — Abhängigkeit vom rechtsatrialen Druckverhalten

Summary The role of atrial natriuretic peptide (ANP) in the pathogenesis of essential hypertension has not yet entirely been clarified. We investigated whether the increase of ANP in essential hypertension may be explained by elevated right atrial pressures and/or a different relationship between right atrial pressures and ANP secretion. Patients with stable essential hypertension undergoing right and left heart catheterization because of suspected coronary heart disease had significantly higher ANP levels than normotensives: 58.7±6.7 pg/ml in hypertensives versus 42.0±4.1 pg/ml in normotensives (p<0,01). Matching hypertensives with normotensives at identical levels of left ventricular enddiastolic pressure revealed significantly higher mean pulmonary artery pressures in hypertensives. Right atrial diastolic pressure (v-wave) after matching for LVEDP was 4.8±0.5 mm Hg in hypertensives and 3.1±0.2 mm Hg in normotensives (p<0.05). In addition, at any given mean right atrial pressure hypertensives showed higher ANP levels than normotensives. These results demonstrate that hypertensives exhibit raised pressures in the pulmonary artery independent of left ventricular pressure load. The elevation in right atrial pressures and the steeper relationship between these pressures and ANP are a suitable explanation for raised ANP levels in hypertension. ANP in essential hypertension may represent a counterregulation against elevated pulmonary resistance.

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Abkürzungsverzeichnis ANP Atriales natriuretisches Peptid - LVEDP Left ventricular enddiastolic pressure (Linksventrikulärer enddiastolischer Druck) - RAO Right anterior oblique (Aufnahmetechnik von rechter schräger Bildröhrenposition aus) - SEM Standard estimate of the mean (Standardabweichung dividiert durch die Wurzel aus der Fallzahl) - HT Hypertoniker - NT Normotoniker Mit Unterstützung der Deutschen Forschungsgemeinschaft     

Zur flammenphotometrischen Calciumbestimmung im Urin

Zusammenfassung Für die Calciumbestimmung im Urin wird eine einfache und rasche flammenphotometrische Methode ohne vorherige Fällung des Calciums beschrieben. Der Kationenfehler kann dabei durch das Korrekturverfahren weitgehend ausgeschaltet werden, der Phosphat- und Sulfatfehler durch das Parallelverfahren, während der Bicarbonatfehler infolge Ansäuerung entfällt.Der mittlere Gesamtfehler der Methode beträgt etwa ± 7% (± 2).     

Progesteron im peripheren Venenblut von Schwangeren mit Spätgestosen

Zusammenfassung 1. Mit einer Modifikation der Methode vonZander undSimmer wird Progesteron im peripheren Venenblut von Schwangeren im IX. und X. Monat und sub partu bestimmt.2. Bei 33 gesunden Schwangeren finden sich durchschnittlich 26,0 Progesteron-% Plasma mit einer mittleren Abweichung von ±15,5, während bei 31 Patientinnen mit essentiellen Spätgestosen im Durchschnitt 29,5±18,0 bestimmt werden. Es besteht hiernach kein sicherer Unterschied zwischen normalen Schwangerschaften und Spätgestosen.3. Auch beim Vergleich einzelner Schwangerschaftsstadien ergeben sich keine Unterschiede. Bei den gesunden Schwangeren werden im IX. Monat 19,0±10,5-%, im X. Monat 33,0±16,5-% und sub partu 24,5±14,5-% gefunden. Die Progesteronwerte betragen bei Patientinnen mit Spätgestosen im IX. Monat 18,5±17,5-%, im X. Monat 31,0±25,0-% und sub partu 34,5±15,5-%.4. Die Unterschiede zwischen den Werten im IX. und X. Monat und sub partu sind deutlich, aber nicht signifikant.5. Die Methode ist nicht empfindlich genug, umdie gestagenen ⁴-3-Ketopregnenole exakt zu bestimmen.6. Die Ergebnisse werden in ihrer Bedeutung für die Schwangerschaftsödeme diskutiert. Es wird in Frage gestellt, ob Progesteron an der Pathogenese der Ödeme bei Patientinnen mit Spätgestosen beteiligt ist.     

Increase in TCRγδ T lymphocytes in synovia from rheumatoid arthritis patients with active synovitis

To determine the relative presence of TCR+ and TCR+ T cells in synovial tissue from patients with various types of inflammatory synovitis and in tissues from patients with a number of chronic T cell-mediated conditions, we stained frozen tissue sections with monoclonal antibodies in indirect immunofluorescence assays. In tissues obtained from patients with chronic T cell-mediated granulomatous conditions (Wegener's granulomatosis, lymphomatoid granulomatosis, granuloma annulare, Langerhan's cells granulomatosis, pigmented villonodular synovitis, Takayasu's arteritis, and talc granulomatosis), the T cells present were predominantly TCR+, without an increased presence of TCR+ cells. In contrast, 6 of 14 (43%) synovia from patients with rheumatoid arthritis (RA) showed increased TCR+ T cells (3–10 cells/hpf). The RA synovia with increased TCR+ cells present had an increased tissue inflammation score compared to RA synovia with few TCR+ cells [18.6±5.8 versus 11.6±4.2 (mean±SE),P<0.05]. In contrast, synovia from patients with osteoarthritis, systemic lupus erythematosus, and trauma did not show an increased presence of TCR+ T cells. Thus, in cellular inflammatory infiltrates the presence of increased TCR cells is not a component of noninfectious granulomatous inflammation but is found in approximately 40% of RA synovia with high levels of inflammation.