ZIB

Hits per page

hits 1 - 4 | 4 hits

Sorting

Electronic Resource

Micropuncture studies on the renal handling of 2,4-diamino-6,7-dimethylpteridine (1979)

Häberle, D. A. ; Schiffl, H. ; Mayer, G. ; [et al.]

Springer

Naunyn-Schmiedeberg's archives of pharmacology 306 (1979), S. 287-293

add to mindlist on the mindlist

Details

ISSN: 1432-1912

Keywords: 2.4-diamino-6.7-dialkylpteridine ; Diuretics ; Micropuncture ; Tubular transport ; Rat kidney

Source: Springer Online Journal Archives 1860-2000

Topics: Medicine

Notes: Summary The excretion of the diuretic substance DADMP (2.4-diamino-6.7-dimethylpteridine) and of DMP (6.7-dimethylpterin) was studied on single nephrons of the rat kidney using microperfusion and microinjection techniques. In the proximal tubule only DADMP was reabsorbed to a significant degree. Fractional reabsorption rate was independent of the load applied and the permeability constant was found to be 2.2·10−4 cm·s−1. Similar results were obtained in nephrons in which the substances, with inulin, were injected from middle proximal tubular puncture sites and recovered in the urine. DMP appeared in the urine quantitatively and simultaneously with the injected inulin. DADMP recovery, however, was only 20–30% of the injected load during the injection period and after 2 h some 70% was recovered from the urine of both kidneys. The reabsorbed fractions were independent of the loads applied, which varied between 2·10−13 mol·min−1 and 10−9 mol·min−1. A comparison of the microperfusion and the microinfusion data suggests that the reabsorption of DADMP occurs predominantly in the proximal convolution, and it appears that the differences between the renal handling of DMP and DADMP are explicable by their different lipid solubilities.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00507116

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Rekonstruktion des vorderen Kreuzbands mit der All-inside-Technik (1998)

Ganzer, D. ; Minnich, S. ; Völker, L. ; [et al.]

Springer

Arthroskopie 11 (1998), S. 68-73

add to mindlist on the mindlist

Details

ISSN: 1434-3924

Keywords: Schlüsselwörter All-inside-Technik ; VKB-Rekonstruktion ; Anatomiegerechte Transplantatfixierung ; Scheibenwischereffekt ; Isokinetiktest ; Key words All-inside technique ; ACL reconstruction ; Anatomically correct graft fixation ; Windshield-wiper effect ; Isokinetic test

Source: Springer Online Journal Archives 1860-2000

Topics: Medicine

Description / Table of Contents: Biomechanically correct positioning of the replacement material is vital for a successful operation in anterior cruciate ligament (ACL) surgery. However, intra-articular fixation of the ACL to the anatomic origin and insertion has not yet been performed using any surgical technique. The transtibial canal is the principle underlying all previous ACL reconstruction operations. External fixation at such a distance exerts substantial strain on the graft in the tibial canal. This strain is due to a “windshield-wiper motion” occurring with each extension and flexion of the knee. Detrimental shearing forces at the graft’s point of exit additionally weaken the replacement material. The all-inside technique is an innovative development in arthroscopic ACL surgery which obviates the need for a transtibial canal and fixes the graft anatomically correctly to the femoral origin and tibial insertion. The way in which the lateral third of the patellar tendon is excised is new. No patellar bone core is removed. Thus long-term post-operative patellar pain, which is otherwise frequent, does not occur. The chief advantages of the all-inside technique are as follows: anatomic graft fixation to the origin and insertion of the ACL; no graft overloading in a transtibial canal, shear stresses and the windshield-wiper effect are eliminated; a dorsally open, tibial fixation angle of the graft, which counteracts ventral translation forces of the tibia; simplified revision possibilities; and a lower morbidity rate. The greatly reduced morbidity of patients operated on with this technique ensures a faster and more successful rehabilitation and a sufficient muscular build-up. For all isokinetic test parameters investigated, the all-inside technique consistently yielded the best results.

Notes: Die biomechanisch und anatomisch korrekte Plazierung des Transplantats ist Grundlage für den Operationserfolg in der vorderen Kreuzbandchirurgie. Eine anatomiegerechte Fixierung am anatomischen Ursprung und Ansatzes des vorderen Kreuzbands konnte aber bisher von keiner Operationstechnik realisiert werden. Grundprinzip aller Ersatzoperationen des vorderen Kreuzbands ist ein transtibialer Kanal, in welchem die Fixierung des Transplantats fern des eigentlichen anatomischen Ansatzes erfolgt. Diese nichtanatomische Fixierung verursacht eine erhebliche Transplantatbeanspruchung im transtibialen Kanal, die auch als Scheibenwischereffekt bezeichnet wird. Zusätzlich erfolgt eine erhebliche Scherbelastung an der Transplantataustrittsstelle, die zu einer zusätzlichen Tranplantatschwächung führt. Die All-inside-Technik ist eine neue, innovative Operationstechnik zur vorderen Kreuzbandrekonstruktion, die auf einen transtibialen Kanal verzichtet und das Transplantat anatomiegerecht fixiert. Das laterale Patellarsehnentransplantat wird mit einer neuen Entnahmetechnik ohne patellaren Knochenblock entnommen. Die postoperative Patellarsehnenproblematik entfällt dadurch. Hauptvorteile der All-inside-Technik sind die anatomiegerechte Transplantatfixierung am anatomischen Ursprung und Ansatz, die fehlende Transplantatüberanspruchung in einem transtibialen Kanal, ein nach dorsal offener tibialer Fixierungswinkel, welcher ventralen Transplantationskräften der Tibia entgegenwirkt, vereinfachte Revisionsmöglichkeiten und eine geringere Gesamtmorbidität. Die Reduktion der Morbidität erlaubt eine schnelle und erfolgreiche postoperative Rehabilitation. Bei allen im Isokinetiktest untersuchten Parametern zeigte die All-inside-Technik die besseren Ergebnisse.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001420050013

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Renal balance of pterin cofactors in the rat (1978)

Häberle, D. A. ; Schiffl, H. ; Mayer, G. ; [et al.]

Springer

Pflügers Archiv 375 (1978), S. 9-16

add to mindlist on the mindlist

Details

ISSN: 1432-2013

Keywords: Pterins ; Micropuncture ; Tubular transport ; Rat kidney

Source: Springer Online Journal Archives 1860-2000

Topics: Medicine

Notes: Abstract In rat kidney, the rate of urinary biopterin [biopterin (B), 7,8-dihydrobiopterin (BH2), and 5,6,7,8-tetrahydrobiopterin (BH4)] excretion as measured by Crithidia assay, was found to be at least 3 times greater than the rate at which it is filtered (GFR·PBiopt.). At a renal blood flow of 6.43±1.34 ml/min per g kidney wt., biopterin concentrations in arterial and renal venous blood and plasma were similar [art. blood: 250±50 ng/ml, ren. venous blood: 247.3±50.9 ng/ml, art. plasma: 23.1±5.8 ng/ml, ren. venous plasma: 23.4±6.9 ng/ml (means±S.D.)]. 14C-BH4 and3H-inulin, infused by means of a micropump into late proximal segments of single nephrons at concentrations of 10−4–10−6 mol, were excreted at similar fractional rates (inulin: 0.85–0.97, BH4: 0.87–0.92, total recovery 1.00–1.09 and 0.99–1.11, respectively). Similar results were obtained with 6,7-dimethylpterin, but not with 6,7-dimethyl-5,6,7,8-tetrahydropterin. The latter is reabsorbed at a fractional rate of 0.20 at concentrations of 10−7 and 10−6 mol. In microperfusion studies in isolated proximal tubular segments in vivo et situ, no reabsorption of 6,7-dimethylpterin could be detected. In case of 6,7-dimethyl-5,6,7,8-tetrahydropterin (DMPH4) at concentrations of 5·10−5 and 10−5 mol/l, however, a permeability constant of 2.39·10−5 cm/s has been measured. From the fact that more biopterin leaves the kidney with urine plus venous blood than entered it is concluded that reduced biopterin is synthesized de novo in the kidney. With the exception of DMPH4, all types of biopterin are not significantly reabsorbed, but rather, are excreted into the urine due to an anisotropic permeability characteristic of the nephron.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00584142

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Das Verhalten der Plasmaaminosäuren bei parenteraler Ernährung mit verschiedenen Aminosäurelösungen (1974)

Miller, B. ; Knauff, H. G. ; Mayer, G. ; [et al.]

Springer

Research in experimental medicine 162 (1974), S. 109-124

add to mindlist on the mindlist

Details

ISSN: 1433-8580

Keywords: Parenteral nutrition ; Amino acid solutions ; Plasma amino acids ; Parenterale Ernährung ; Aminosäure ; Infusionslösungen ; Aminosäuremuster im Plasma

Source: Springer Online Journal Archives 1860-2000

Topics: Medicine

Description / Table of Contents: Zusammenfassung 1. Bei gesunden Versuchspersonen, die mit einer calorisch ausreichenden stickstofffreien Diät ernährt wurden, wurden 3 verschiedene Aminosäurelösungen als einzige Stickstoffquelle parenteral zugeführt. Am 3. Infusionstag wurde die Konzentration der freien Aminosäuren im Plasma vor, während und am Ende der Infusion sowie 30, 60 und 180 min nach dem Absetzen bestimmt. Die Nüchternwerte wurden am 1., 3. und 5. Infusionstag bestimmt und miteinander verglichen. Am 3. Infusionstag wurde außerdem die Ausscheidung der verschiedenen Aminosäuren im Harn gemessen. 2. Während und nach der Infusion ergaben sich starke Veränderungen in der Konzentration der meisten Aminosäuren im Plasma. Dadurch wurde die physiologische Relation der einzelnen Plasmaaminosäuren mehr oder weniger verschoben. Die langfristige Verabreichung der Infusionslösungen führte zu Verschiebungen auch der Nüchternwerte und zu einem Anstieg des Gesamtaminostickstoffs im Plasma. 3. Die Unterschiede zwischen dem Verhalten der Plasmaaminosäuren nach den verschiedenen Infusionslösungen lassen sich mit der durch Stickstoffbilanzuntersuchungen an den gleichen Versuchspersonen gesicherten unterschiedlich guten biologischen Wertigkeit der Lösungen korrelieren. Die Lösung, die die beste Stickstoffbilanz ergeben hatte, bewirkte auch die geringsten Veränderungen im Aminosäurespektrum des Plasmas.

Notes: Summary Three different amino acid solutions as only source of nitrogen were infused in healthy volunteers taking a nitrogen-free high-caloric diet orally. On the 3rd day of parenteral nutrition the concentration of the free plasma amino acids were determined before, during, on termination, and 30, 60 and 180 min after the infusion. The fasting levels were determined on the 1st, 3rd and 5th day of infusion. The urinary amino acid excretion was measured on the 3rd day. During and after the infusion significant alterations in the concentration of most amino acids were observed. The physiological pattern of plasma amino acids was altered temporarily. The long-term administration of plasma amino acid solutions altered the fasting levels somewhat and increased the total amino nitrogen in the plasma. The different effect of the three solutions on amino acid levels in plasma was correlated to differences in the biological value of these solutions as observed in nitrogen balance studies in the same subjects. The amino acid solution with the best results in nitrogen balance studies lead to the smallest changes in the pattern of plasma amino acids.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF01851609

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

hits 1 - 4 | 4 hits