Two brothers with characteristic facial appearance, severe psychomotor retardation, hypospadias, contractures, and other symptoms: a new recessive syndrome?

We report on two severely mentally retarded male children of consanguineous parents who seem to be affected by an identical syndrome. The main physical anomalies are typical facial stigmata with a broad nasal bridge, a bulbous nose, upward slanting palpebral fissures, microretrognathia, low hair line, and large ears with an incompletely developed upper helix. In addition, both brothers had hypospadias type II, limb contractures, and delayed bone age.

In man histamine and muscarinergic mechanisms are essential mediators of acid secretion in response to synthetic human gastrin (1-17).

It is still controversial whether gastrin stimulates acid secretion by interacting with specific gastrin receptors on parietal cells or via endogenous mediators, e.g., histamine.

Leukotrienes C4 and D4 potentiate acid production by isolated rat parietal cells.

The effects of leukotrienes (LTs) B4, C4, and D4 on acid production by enriched (80%-85%) rat parietal cells were investigated. Acid production was indirectly measured by [14C]aminopyrine uptake into the cells. Leukotriene B4 (10(-10)-10(-6) mol/L) had no effect on basal or prestimulated [14C]aminopyrine uptake.

The medullary microcirculation.

Like other regional circulations, the medullary circulation supplies oxygen and other primary substrates to the medulla and removes carbon dioxide and other waste metabolites. It also acts as a countercurrent exchanger and simultaneously removes water reabsorbed from the renal tubule to preserve mass balance. Our present understanding of how the medulla serves both these functions at the same time is illustrated in Figure 3.

The shape of renal vasa recta capillaries and its effect on calculation of single capillary blood flow.

Previous studies of the renal papilla of the rat have suggested that the vasa recta capillaries can be well approximated by elliptical cylinders (C. Holliger, K. V.

Erythrocyte flow and dynamic hematocrit in the renal papilla of the rat.

The microcirculation of the renal papilla was investigated in 32 vasa recta of Wistar rats. Using fluorescence microscopy in combination with a high-sensitivity television system we measured the velocity and flux of fluorescent-tagged erythrocytes in descending (DVR) and ascending vasa recta (AVR). After staining the plasma with fluorescent high molecular weight dextran we determined the diameters of DVR and AVR.

Effect of arginine vasopressin on renal medullary blood flow. A videomicroscopic study in the rat.

The role of arginine vasopressin (AVP) in the regulation of renal medullary blood flow is uncertain. To determine if AVP has a direct vasoconstrictive action on vasa recta, the effect of AVP on erythrocyte velocity (VRBC), diameter, and blood flow (QVR) in descending vasa recta (DVR) and ascending vasa recta (AVR) was studied in the exposed renal papilla of four groups of chronically water diuretic rats using fluorescence videomicroscopy. There were three periods: control (period 1), experimental (period 2), and recovery (period 3).

Use of digital cross-correlation for on-line determination of single-vessel blood flow in the mammalian kidney.

The empirical relationship between erythrocyte velocity (Vrbc) and mean blood velocity (Vblood) was studied in quartz capillaries by television microscopy using the dual-slit technique. A newly designed desktop digital on-line cross-correlator was combined with a computer to determine Vrbc. The accuracy of the digital correlator was tested for velocities ranging from 0 to 3 mm/sec and compared with values determined using an analog tracking correlation device.

Fluid uptake in the renal papilla by vasa recta estimated by two methods simultaneously.

Fluid uptake by vasa recta was determined by two independent methods, videomicroscopy and the micropuncture technique, in the exposed papilla of nine antidiuretic rats to reconcile differences in values previously obtained by the two techniques. Erythrocyte velocity (Vrbc) and diameter (D) in descending vasa recta (DVR) (n = 22) and ascending vasa recta (AVR) (n = 31) near the "base" of the papilla were measured. Using a conversion function determined in vitro, Vrbc was transformed into mean blood velocity (Vblood).

Videomicroscopic method for direct determination of blood flow to the papilla of the kidney.

We adapted the technique of videomicroscopy for direct determination of blood flow in individual capillaries of the papilla of the kidney, the ascending vasa recta (AVR) and descending vasa recta (DVR). The papilla was exposed in anesthetized rats and positioned under a video-camera-microscope and viewed under epiillumination. The intravenous infusion of fluorescein-isothiocyanate (FITC)-labeled gamma globulin was combined with fluorescence microscopy to enhance the contrast among plasma, red blood cells and capillary walls.

Influence of systemically applied angiotensin II on the microcirculation of glomerular capillaries in the rat.

The effect of intravenous infusion of angiotensin II on microvascular parameters of the renal microcirculation of rats was studied. With the aid of fluorescence microscopy and a high sensitivity video system we observed the passage of fluorescence-labeled erythrocytes through single glomerular capillaries on the surface of the rat kidney. From videotaped recordings, we measured the velocity and the flux of erythrocytes using a modified dual-slit technique with support of a microprocessor system.

The use of fluorescent labeled erythrocytes for intravital investigation of flow and local hematocrit in glomerular capillaries in the rat.

Fluorescence labeled erythrocytes are suitable markers for red cell velocity and red cell flux through glomerular capillaries in incident light fluorescence microscopy. Mean velocity of the labeled cells was measured from a video recording with a microprocessor using a modified dual slit photometric technic. Red cell flux through the capillary was derived from the labeled cell frequency in capillary flow and systemic concentration of the fluorescent cells.

Intraglomerular microcirculation: measurements of single glomerular loop flow in rats.

With the use of a new fluorescent microscopic technique, we were able to measure the mean intracapillary velocities and pressures of single capillary loops of renal glomeruli of living rats. The technique involved photographing and recording the flow of fluorescent latex particles through the glomerular loops with a television monitor. In 25 rats the single glomerular loop flow velocity was 781 +/- (SD) 271 micrometers .