U. Binswanger

Unidirectional duodenal and jejunal calcium and phosphorus transport in the rat: Effects of dietary phosphorus depletion, ethane-1-hydroxy-1,1-diphosphonate and 1,25 dihydroxycholecalciferol

SummaryUnidirectional calcium (Ca) and phosphorus (Pi) transport was studied in vitro by means of a modified Ussing technique in the absence of electrochemical gradients between the mucosal and serosal buffer medium. Duodenum and jejunum of male albino Sprague-Dawley rats were investigated after Pi depletion alone (0.03% diet-Pi), Pi depletion and EHDP treatment (40 mg/kg per day s.c. × 4), and Pi depletion, EHDP and 1,25(OH)2D3 (500 pmol i.v. × 2) treatment. Mucosal-to-serosal Ca and Pi fluxes (Jms) changed in parallel, depending on the 1,25(OH)2D3-status of the animals. Regarding serosal-to-mucosal fluxes (Jsm), Pi depletion resulted in an increase in Jsm for Ca and Pi, associated with a rise in Gt and Isc in the duodenum but not in the jejunum. EHDP administered to block synthesis of 1,25(OH)2D3 caused further augmentation in duodenal Jsm for calcium but not phosphorus, which was paralleled by an increase in Gt and Isc. After repletion with 1,25(OH)2D3, an increase in Jsm for Ca and Pi and a rise in Gt and Isc were observed in the duodenum and in the jejunum. Serosal-to-mucosal fluxes for Ca and Pi were related to tissue conductance (Gt) in the duodenum (r = 0.89,P < 0.001 andr = 0.84;P < 0.001, respectively), as well as in the jejunum (r = 0.55;P < 0.01 andr = 0.66;P < 0.001, respectively). Changes in Jsm also paralleled changes in transmural shortcircuit current (Isc). The data are compatible with the assumption of an increase in Jsm for Ca and Pi and a rise in Gt, both reflecting an increase in water recycling across the tight junctions caused by a rise in sodium absorption. They provide further evidence that the overall effect of 1,25(OH)2D3 on intestinal Ca and Pi transport is to increase both cell-mediated active mucosal-to-serosal transport and paracellular diffusional serosal-to-mucosal ion movement.

Calcium and inorganic phosphate secretion of rat ileum in vitro. Influence of uremia and 1,25 (OH)2D3 inhibition.

SummaryThe unidirectional ileal transport of calcium (Ca) and inorganic phosphorus (Pi) of rats was measured in vitro with the modified Ussing technique. Animal preparation included 5/6 nephrectomy and EHDP treatment. They were compared to controls as well as to 1,25 (OH)2D3 supplemented rats. The results show that the ileum is a secretory organ for Ca and Pi, the serosa to mucosa transport (Jsm) exceeds the mucosa to serosa transport (Jms). Ca and Pi transport in sm direction is 1,25 (OH)2D3 independent but exhibits a mutual strong correlation. Our observations together with published data are in favor of mainly paracellular, non electrogenic sm transport of both ions. However, the factor controlling sm transport of Ca and Pi remains unidentified. The mucosa to serosa transport (Jms) in the ileum is low for both ions. Ca ms is stimulated by 1,25 (OH)2D3, Pi ms is unchanged.

Arterienstenosen nach Nierentransplantation

SummaryAfter 268 kidney allotransplants, 7 cases of renal artery stenosis were observed. An additional 3 patients were referred to us from another center. The outstanding symptom of all 10 patients was hypertension refractory to medical treatment, beginning not later then 10 months after transplantation. In 9 cases there was a murmur over the transplant. In 6 patients hypertension was accompanied by a deterioration of renal function which was resistant to antirejection therapy. The tentative diagnosis was confirmed by selective renal arteriography of the transplant. Two main types of stenoses could be diagnosed: Segmental stenoses, 0.5–2 cm distal to the anastomosis, which were due to intimal lesions caused during removal of the kidney or by the perfusion canula; and kinking stenoses due to a technically inadequate implantation. Hypertension was controlled in all but 1 patient with reconstruction of the artery. Therefore, hypertension after kidney transplantation refractory to medical treatment should be further investigated with selective renal arteriography of the transplant. Stenoses with clinical symptoms which are confirmed by arteriography should be surgically corrected.ZusammenfassungNach 268 Nierentransplantationen trat in 7 Fällen eine Transplantatarterienstenose auf. Drei weitere Patienten wurden von einem anderen Zentrum überwiesen. Das Hauptsymptom der Nierenarterienstenose war bei allen 10 Patienten eine innerhalb von 10 Monaten aufgetretene, medikamentös nicht beherrschbare Hypertonie. In 9 Fällen fand sich ein Stenosegeräusch über dem Transplantat. In 6 Fällen war die Hypertonie von einer leichten, auf Abstoßungstherapie nicht ansprechenden Funktionsverschlechterung begleitet. Bestätigt wurde die klinische Verdachtsdiagnose durch eine selektive Transplantatarteriographie. Es ließen sich 2 Haupttypen von Stenosen feststellen:Segmentstenosen, die immer 0,5-2 cm distal der Anastomose auftreten und durch Intimaläsionen anläßlich der Entnahme und Perfusion verursacht werden, und Knickstenosen infolge technisch fehlerhafter Arterienimplantation. Mit einer Ausnahme ließ sich die Hypertonie durch die Gefäßrekonstruktion unter Kontrolle bringen. Jede medikamentös nicht beherrschbare Hypertonie nach Nierentransplantation muß durch eine selektive Transplantatarteriographie abgeklärt werden. Angiographisch nachgewiesene, klinisch manifeste Stenosen sollten operiert werden.After 268 kidney allotransplants, 7 cases of renal artery stenosis were observed. An additional 3 patients were referred to use from another center. The outstanding symptom of all 10 patients was hypertension refractory to medical treatment, beginning not later then 10 months after transplantation. In 9 cases there was a murmur over the transplant. In 6 patients hypertension was accompanied by a deterioration of renal function which was resistant to antirejection therapy. The tentative diagnosis was confirmed by selective renal arteriography of the transplant. Two main types of stenoses could be diagnosed: Segmental stenoses, 0.5-2 cm distal to the anastomosis, which were due to intimal lesions caused during removal of the kidney or by the perfusion canula; and kinking stenoses due to a technically inadequate implantation. Hypertension was controlled in all but 1 patient with reconstruction of the artery. Therefore, hypertension after kidney transplantation refractory to medical treatment should be further investigated with selective renal arteriography of the transplant. Stenoses with clinical symptoms which are confirmed by arteriography should be surgically corrected.

Akute Leukämie nach Nierentransplantation

SummaryFour cases of acute myelogenous leukemia and six cases of chronic myelogenous leukemia after treatment with azathioprine and prednisone for renal allotransplantation have been described in the literature. We report another two cases of acute leukemia 10 and 5 years after successful renal allotransplantation. Patient 1, a 29-year-old farmer, exhibited the signs of acute lymphatic leukemia resistent to treatment with cytostatic agents. Death was due to pneumonia. Patient 2, a 47-year-old salesman, developed pancytopenia together with splenomegaly. After splenectomy an atypical subacute myeloid leukemia became apparent which was not treated due to withdrawal of the patient. He died 2 months after diagnosis. Both patients received long-term immunosuppressive therapy with azathiopine and prednisone until the leukemia was diagnosed. A relationship between long-term immunosuppression and the occurrence of leukemia is postulated.ZusammenfassungIn der Literatur sind vier Fälle mit Entwicklung einer akuten myeloischen und sechs Fälle mit Entwicklung einer chronischen myeloischen Leukämie unter Immunosuppression mit Azathioprin und Prednison bei nierentransplantierten Patienten beschrieben. Wir berichten über zwei weitere akute Leukämien während chronischer Immunosuppression bei Zustand nach Nierentransplantation. Der erste, 29jährige Patient entwickelte zehn Jahre nach erfolgreicher Nierentransplantation die Zeichen einer akuten lymphatischen Leukämie. Beim zweiten, 47jährigen Patienten wurden fünf Jahre nach erfolgreicher Nierentransplantation Hepatosplenomegalie und Pancytopenie beobachtet; nach Splenektomie wurde die Diagnose einer subakuten myeloischen Leukämie gestellt. Beide Patienten standen unter langdauernder immunosuppressiver Therapie (Azathioprin und Prednison),die in beiden Fällen nach der Diagnose einer Leukämie abgesetzt wurde. Ein Zusammenhang zwischen dem Auftreten der Leukämie und der chronischen Immunosuppression wird postuliert.Four cases of acute myelogenous leukemia and six cases of chronic myelogenous leukemia after treatment with azathioprine and prednisone for renal allotransplantation have been described in the literature. We report another two cases of acute leukemia 10 and 5 years after successful renal allotransplantation. Patient 1, a 29-year-old farmer, exhibited the signs of acute lymphatic leukemia resistent to treatment with cytostatic agens. Death was due to pneumonia. Patient 2, a 47-year-old salesman, developed pancytopenia together with splenomegaly. After splenectomy an atypical subacute myeloid leukemia became apparent which was not treated due to withdrawal of the patient. He died 2 months after diagnosis. Both patients received long-term immunosuppressive therapy with azathiopine and prednisone until the leukemia was diagnosed. A relationship between long-term immunosuppression and the occurrence of leukemia is postulated.

Intravenous spiral support for the prevention of outflow-tract stenosis in av-shunts for hemodialysis?

SummaryIntraluminal spiral support of bovine heterografts (Solcograft-P) offers promising mechanical characteristics for av-shunts. Using a tunneling technique the spiral prevents twisting and kinking during subcutaneous placement and allows prolonged and vigorous post-puncture compression for hemostasis without compromising shunt flow. Canine experiments (femorofemoral loop) suggest that additional insertion of the spiral into the efferent vein for some centimeters can prevent or delay the development of outflowtract stenosis, the main cause of late shunt failure (0% (0/5) vs. 75% (3/4) significant stenosis; total patency rate 90% (9/10); follow-up 3 months). Preliminary clinical results with brachio-cephalic/basilic av-shunts in the forearm (loop) support our experimental investigations. In all eight patients the shunt is functioning perfectly without reinterventions being necessary (mean follow-up 8.8 months, totally 55 dialysis months). In five patients the shunt was used early for hemodialysis (days 1–10 post operation). Angiographically, stenoses developed in the outflow-tract in five of six shunts, but only one stenosis was observed in the spiral-supported venous segment where it usually occurs. In some cases shunt function was preserved by collaterals from the nonstenotic spiral-supported venous segment despite occlusion of the main efferent vein. Thus, it appears that a spiral placed into the graft and efferent vein is suitable to prolong the functional life of av-shunts.

[Colonic complications after renal transplantation (author's transl)].

SummaryFrom December 1964 to June 1980, 569 kidney allotransplants were performed in 524 patients at the University Hospital in Zurich. Necrokidneys were used exclusively. Twelve of these patients exhibited severe colonic complications: four perforations (1 perforated diverticulitis of the sigmoid, 1 perforation of the cecum during cytomegalovirus infection, 2 cases of ischemic colitis), 5 cases of ischemic colitis without perforation, and 3 patients with erosive colitis. In 9 of the 12 patients, hypotonic episodes were noted 4–17 days previously. The 2 % complication rate in our patients is comparable with the mean rate of complications mentioned in the literature (2.4 %). The lethality of 75 % also corresponds with the results of other authors. The most important pathogenetic factor for colonic complications is ischemia; prevention of hypotonic episodes after renal transplantation is therefore mandatory.ZusammenfassungVom Dezember 1964 bis Ende Juni 1980 wurden im Universitätsspital Zürich bei 524 Patienten total 596 Nierenallotransplantationen durchgeführt unter ausschließlicher Verwendung von Nieren Frischverstorbener. Bei einer Nachkontrollzeit von minimum 1

Acute leukemia after kidney allotransplantation

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Colonic complications after renal transplantation

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Arterial stenosis after kidney transplantation

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