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With a lung ultrasound (LUS) the typical findings are interstitial pneumonia. COVID-19 pneumonia is often manifested in sub-pleural areas, which is preferably detected by sonography. An RT-PCR test cannot always ensure a safe differentiation of COVID-19- and non-diseased cases. Clinically challenging is that a reliable and time efficient decision regarding COVID-19 suspects requiring isolation. Therefore, this study was aimed at evaluating the significance of LUS in symptomatic patients with COVID-19 suspicion at hospital admission. A total of 101 patients admitted to a suspect ward with COVID-19-typical symptoms were assessed. All patients received prospectively a standardized LUS at admission. Patients were classified as LUS-positive and -negative cases based on a specific LUS score. The RT-PCR test in combination with the clinical findings served as a reference. Correctly classified were 14/15 COVID-19 diseased suspects as LUS-positive (sensitivity: 93.3%). Twenty-seven out of 61 non-positive cases were classified as false positive with LUS (specificity: 55.7%). In 34/35 patients who were assessed as LUS negative, no COVID-19 disease was detected during the hospitalization. The PPV and NPV of the LUS were 34.1% and 97.1%. LUS is a valuable tool in symptomatic patients for the assessment of COVID-19-disease. The high negative predictive value of LUS is helpful to rule out the disease.

Lung ultrasound (LUS) is a practical tool for lung diagnosis when computer tomography (CT) is not available. Recent findings suggest that LUS diagnosis is highly advantageous because of its mobility and correlation with radiological findings for viral pneumonia. Simple models for both educational evaluation and technical evaluation are needed. Therefore, this work investigates the usability of a large animal model under aspects of LUS features of viral pneumonia using saline one lung flooding. Six pigs were intubated with a double-lumen tube, and the left lung was instilled with saline. During the instillation of up to 12.5 ml/kg, the sonographic features were assessed. All features present during viral pneumonia were found, such as B-lines, white lung syndrome, pleural thickening, and the formation of pleural consolidations. Sonographic findings correlate well with current LUS scores for COVID19. The scores of 1, 2, and 3 were dominantly present at 1-4-, 4-8-, and 8-12-ml/kg saline instillation, respectively. The noninfective animal model can be used for further investigation of the LUS features and can serve in education, by helping with the appropriate handling of LUS in clinical practice during management of viral pneumonia.

Calciphylaxis is a rare syndrome mostly affecting patients with secondary hyperparathyroidism and in some cases with functional protein C or protein S deficiency. Skin lesions begin as superficial painful patches that progress to deep necrotic lesions. The findings are often misdiagnosed as livedo vasculitis and the prognosis is poor. Histopathologically, calcification in the media of small arteries and arterioles with intimal hyperplasia is seen. It is unclear if this morphologic hallmark is pathogenetic. Therapeutically, the calcium-phosphate product should be lowered pharmacologically by an intensified and modified dialysis treatment and parathyroidectomy.

Unlabelled: Intrarenal handling of 99mTc-DMSA is still controversial, particularly in the existence of tubular reabsorption from the tubular fluid. Experiments were performed with micropuncture technique on the rat kidney in an attempt to elucidate this question., Methods: The concentration profile of 99mTc-DMSA along the nephron was measured in fluid from Bowman's space of surface glomeruli and from the proximal and distal tubules collected by micropuncture. Superficial loops of proximal tubules were micropunctured and microperfused with 99mTc-DMSA or [99mTc] pertechnetate for 10 or 20 min at physiological flow rates; the recovery of activity was measured in the final urine., Results: Bowman's space urine contained only 14% of the 99mTc activity of arterial plasma, indicating low filtration of 99mTc-DMSA, likely due to high plasma protein binding. Tubular fluid-to-plasma activity ratios of 0.31 in the proximal tubules and 1.31 in the distal tubules suggest that 99mTc-DMSA is neither secreted nor reabsorbed along the nephron. Ninety-eight percent of the 99mTc-DMSA activity was recovered in the final ipsilateral urine, while only 0.5% was found in the urine of the contralateral kidney., Conclusion: A low fraction of 99mTc-DMSA enters the tubule by glomerular filtration and is not reabsorbed from the tubular fluid. Thus, only peritubular extraction by the tubular cell is responsible for renal uptake of 99mTc-DMSA.

Indications for intercorporal fusion are progressive spondylolisthesis in children and adolescents, painful segmental instability in adults (spondylolisthesis, post-discectomy-syndrome, failed-back-syndrome). From 1980-86 152 isolated anterior intercorporal fusions had been realized, and in 1987/88 we carried out 79 combined anterior-posterior fusions. The rate of pseudarthrosis has been 25% with isolated anterior fusion and on the contrary 9% with combined fusion. With combined fusion the rate of complications did not increase, but the objective and subjective results became better. The postoperative period became more convenient, the stay in hospital and the consolidation of fusion were shorter. The reposition of spondylolisthesis was durable and the spine channel was accessible. We consider the instrumented fusion to be a complex reconstructive operation with high chances of success.

Experiments were conducted to establish whether diminished solute reabsorption in the loop of Henle during acute renal failure could explain the loss of urinary concentration and participate in generating a tubuloglomerular feedback-mediated reduction in filtration rate. The electrolyte content of the fluid in the ascending limb of the loop of Henle was determined in situ by monitoring its electrical conductivity after propulsion into the distal tubule with a sudden burst perfusion. The value of the minimum electrolyte concentration decreased exponentially with increasing equilibration time, reaching a steady-state value equivalent to 27 +/- 9 mM NaCl in normal kidneys, 34 +/- 15 mM in mercuric chloride kidneys and 53 +/- 22 mM following ischaemia. A mathematical model was derived to describe the process of sodium chloride dilution from which it was possible to calculate both the permeability and transport velocity of the cortical thick ascending limb. In the normal kidney, the transport velocity was calculated to be 4.65 +/- 0.92 . 10(-5) cm/s, a value not significantly different from that of the mercuric chloride of ischaemic kidneys, and the estimated permeability was 1.13 +/- 0.52 . 10(-5) cm/s, not different from that of the mercuric chloride kidneys but significantly lower than that calculated for the ischaemic kidneys. It is concluded that for the more severely damaged ischaemic model, the loss of urinary concentrating ability was accompanied by a reduction in diluting ability of the ascending limb of the short loop of Henle, which appears to be due, at least in part, to an elevation of the passive permeability to sodium chloride in this segment.

Distal convoluted tubule reabsorptive fluxes for various substances have been measured using the technique of in vivo microperfusion with quantitative sampling of the perfusate after it traverses a known length of tubule. It is unclear, a priori, whether physiologic pressures can be maintained under these sampling conditions. The present experiments were designed to monitor these pressure changes continuously by means of a microtransducer. We have found that over the range of 10-20 nL/min, during repeat sampling, the rise in pressure is 0.11 mmHg X nL-1 X min-1 (1 mmHg = 133.322 Pa) a value which is similar to 0.15 mmHg X nL-1 X min-1 obtained without sampling. This small rise in pressure over the microperfusion range supports the view that this technique does not introduce unphysiologic pressure effects. The present study also provides for the first time directly measured in vivo distal tubule pressure values over a wide flow range without changing whole kidney urine flow.

Unlabelled: In order to analyze the role of afferent vasomotor activity in mediating tubuloglomerular feedback response, we studied the effect of the intravenously applied Ca++ antagonist Verapamil on proximal stop flow pressure (SFP). In Wistar rats SFP was recorded continuously upstream of a solid paraffin block under either zero or 50 nl/min loop perfusion rate with artificial tubular fluid. The latter elicits maximal feedback response. Similar experiments were performed on heminephrectomized rats which are known to exhibit a highly sensitive feedback response., Results: Verapamil given as a single dose (0.05-0.15 mg/kg b.w., i.v.) resulted in a transient decrease of mean arterial blood pressure of about 10 to 20 mmHg (1 to 3 min), SFP was unaltered during zero loop perfusion. Verapamil applied during a feedback stimulated SFP decrease (50 nl/min loop perfusion) caused restoration of normal SFP for 6 to 10 min indicating an acute and reversible interference of this drug with feedback regulation. Reversal of feedback response was complete in both groups of rats irrespective of the large difference in their feedback sensitivity. Thus: 1. The Ca++ antagonist is a complete inhibitor of feedback mediated SFP changes, 2. decreased SFP during high loop perfusion rate could be titrated back to normal by continuous infusion of Verapamil (dose 0.04 mg/kg-min), 3. Furthermore, feedback regulation of SFP could be prevented by infusion of the drug just prior to increasing loop perfusion rate.

Micropuncture experiments were carried out on rat kidneys in order to analyze the diluting ability of the thick ascending limb of Henle's loop (TAL) after acute and chronic administration of cyclosporine. Male albino Wistar rats weighing 190 to 250 g were either given cyclosporine (CSA) orally for 10 days or received single i.v. infusions of the drug before the micropuncture experiments. Drug free vehicle was administered to animals of two respective control groups. The electrolyte concentration of fluid from individual TALs was measured by continuous conductivity monitoring of early distal tubular fluid during pulse perfusion procedures. The transport dependent decrease of the electrolyte concentrations within the diluting segment showed a semi-logarithmic time course in all groups of rats. Lowest conductivity values were reached within 60 seconds of flow equilibrium in controls as well as in CSA treated rats. Chronic CSA feeding (15 mg/24 h/kg b.w., dissolved in 0.3 ml olive oil) as well as a single i.v. infusion of 5 mg/kg b.w. resulted in a significantly higher electrolyte concentration of TAL fluid. Infusion of the solvent alone was without significant effect on the diluting segment. We conclude that the impairment of the diluting ability of the TAL and hence the delivery of tubular fluid with increased NaCl concentrations to the macula densa should lead to a stimulation of the tubulo-glomerular feedback mechanism. Feedback activation per se could be the cause of the consistent GFR decrease and thus contribute to the basic nephrotoxicity of CSA.

To assess the action of piretanide, bumetanide, and furosemide on the thick ascending limb of Henle's loop, perfusion experiments were performed on rat kidneys, using a recently developed conductivity microprobe for the analysis of distal tubular fluid. Surface nephrons were perfused downstream from a solid paraffin block through Henle's loop with isotonic saline solution containing either 10(-6), 3 X 10(-6), or 10(-5) mol/L piretanide, bumetanide, or furosemide, respectively. For control values, diuretic-free saline was used. Conductivity measurements of early distal tubular fluid were performed in situ with a conductivity microprobe and were recorded continuously during variations of loop perfusion rate. A recently described micro-stop-flow technique was used to measure the conductivity of fluid emerging from the ascending limb, thereby evaluating the amount of sodium chloride reabsorbed. A significant electrolyte transport inhibition occurred within the concentration range between 10(-6) and 10(-4) M. Bumetanide and piretanide were slightly more effective than furosemide. Luminal diuretic concentrations of 10(-6) M or below were without influence on electrolyte reabsorption. Concentrations of 10(-4) M resulted in complete inhibition of the diluting segment electrolyte transfer.