J P Vroemen

Maastricht University, Maastricht, Provincie Limburg, Netherlands

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Publications (16)33.9 Total impact

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    ABSTRACT: Forty-one (impending) fractures were reviewed in 39 patients with metastatic bone disease. Thirty-one lesions were located in the femur, and the remaining ten lesions were located in the humerus. In 22 cases there were multiple lesions in the affected bone. All patients were treated with intramedullary nailing, 21 times because of a pathologic fracture and 20 times because of an impending pathologic fracture. There was no mortality related to the surgical procedures. In nine patients the postoperative course was complicated (four technical and five systemic complications). Pain relief was achieved in 29 patients. Ambulatory status was improved in 27 patients. A pathologic refracture in the same bone occurred in five cases, all located in the femoral neck. Intramedullary nailing is useful in the treatment of metastatic bone disease. This technique facilitates stabilization of the whole bone, which in our view, with respect to the presented data, is mandatory.
    The Journal of trauma 03/1994; 36(2):211-5. · 2.96 Impact Factor
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    ABSTRACT: The growing success in renal transplantation has resulted in an increase in the need for donor organs. Procurement of kidneys from heart-beating (HB) donors is unlikely ever to meet this demand. Non-heart-beating (NHB) donors offer a yet untapped source of renal grafts. Cadaver kidneys from patients who have sustained cardiac standstill are often considered unsuitable for transplantation due to prolonged warm ischemia time. Using an emergency in situ perfusion technique it is possible to limit warm ischemic damage and to salvage these kidneys for transplantation. The procedure requires prompt action and cooperation of emergency service personnel. This report presents a protocol for the emergency in situ preservation procedure that can be practiced in most hospitals. At the University Hospital of Maastricht, The Netherlands, implementation of this procedure resulted in 20% more kidneys available for transplantation. Although NHB donor kidneys showed a higher rate of delayed function compared with a matched HB donor kidney population, there was no significant difference in long-term graft survival between the two groups.
    Transplantation 10/1993; 56(3):613-7. · 3.78 Impact Factor
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    ABSTRACT: Immobilization of the knee as part of the treatment in bone or joint lesions leads to atrophy and consequently loss of functionally. In patients this atrophy and loss of functionality is difficult to quantify because of interfering symptoms and missing baseline data. In the present study structural and functional changes in thigh muscles were examined in eight healthy volunteers of whom one leg was immobilized in a cast for four weeks. Quadriceps cross-sectional area determined with computed tomography was 21% +/- 7% diminished after four weeks immobilization (p < 0.05). Muscle biopsies from the musculus vastus lateralis revealed an 16% decreased fiber diameter (p < 0.05) and no significant shift in fiber types. Isokinetic strength measurements of knee extensors and flexors demonstrated a fall in peak torque of 53% +/- 9% and 26% +/- 13% at an angular velocity of 60 deg.s-1 (p < 0.01). Aerobic power in one-leg-cycling exercise was not significantly affected, but isokinetic quadriceps endurance work decreased from 9.1 kJ to 5.6 kJ (p < 0.05). Despite the fall in quadriceps performance the subjects had only minor functional complaints for a few days. It is concluded that immobilization of the knee is an important factor in the development of thigh muscle atrophy in patients and should therefore be diminished as much as possible.
    International Journal of Sports Medicine 07/1993; 14(5):283-7. · 2.37 Impact Factor
  • Transplantation Proceedings 03/1993; 25(1 Pt 2):1503-4. · 0.95 Impact Factor
  • International Journal of Sports Medicine 01/1993; 14(05):292-292. · 2.37 Impact Factor
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    ABSTRACT: The cytokinetic behavior of isolated hepatocytes transplanted into the spleen of syngenic normal Wistar rats was studied. Hepatocyte transplantation (HTX) was performed by the intrasplenic injection of 10(7) isolated hepatocytes. The proliferation index (PI) of intrasplenic donor hepatocytes was assessed by immunocytochemical visualization of DNA-synthesizing cells after pulse-labeling with bromodeoxyuridine (BrdU), a thymidine analogue. A method for determination of intrasplenic liver mass based on tissue glutamate dehydrogenase content was developed. The spontaneous PI of donor hepatocytes at 12 and at 20 weeks post-HTX amounted to around 3%. A significant increase of intrasplenic liver mass was demonstrated between the 12th and 20th week post-HTX (from 8.1 +/- 0.8% to 10.8 +/- 0.8% of spleen weight, P less than 0.05). After partial hepatectomy (PH) at 12 weeks post-HTX, the PI of liver cells in the spleen showed a transient increase up to about 10%, which rapidly declined to the "spontaneous" level of 3%. However, PH did not cause an additional increase in intrasplenic liver mass. This study shows that continuous mitotic activity of intrasplenic hepatocytes results in an actual increase of liver mass in spleen. Although a short-lived increase of proliferative activity of ectopically grafted hepatocytes was shown to occur after PH in the HTX-treated rat, this procedure did not result in an additional increase of intrasplenic liver tissue.
    Transplantation 04/1988; 45(3):600-7. · 3.78 Impact Factor
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    ABSTRACT: In previous research into hepatocyte transplantation (HTX) the spleen was the preferred acceptor organ for isolated donor hepatocytes. In this study the pancreas was tested as an acceptor organ for HTX. HTX into the pancreas or spleen was performed by injection of 10(7) isolated hepatocytes into the parenchyma of these organs. Intrapancreatic hepatocytes showed good viability 3 months after syngenic HTX as assessed by histological and immunocytochemical parameters. Definite proof of sustained metabolic activity of normal hepatocytes, 3 months after transplantation into the pancreas of congenitally jaundiced rats, was obtained by demonstration of bilirubin conjugates in bile of the recipients: 4.0% of total biliary bilirubin was conjugated. Intrasplenic HTX, however, was more effective and resulted in a conjugated fraction of 17.7% of total biliary bilirubin (p less than 0.001). Reduction of total plasma bilirubin was significant with both methods, but more pronounced in intra-splenic HTX. Bile drainage from the hepatocellular transplant via the pancreatic excretory system into the gut was not observed: conjugated bilirubins were not found in pancreatic juice of HTX-treated jaundiced rats. Intrapancreatic HTX did not adversely affect the host rat; evidence of pancreatitis or diabetes was not found. It is concluded that the pancreas is a suitable acceptor organ for HTX. However, intrapancreatic HTX appears to be less effective than intrasplenic HTX in the treatment of enzyme deficiency disease.
    European Surgical Research 02/1988; 20(1):1-11. · 1.43 Impact Factor
  • Transplantation Proceedings 11/1987; 19(5):3927-9. · 0.95 Impact Factor
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    ABSTRACT: In vivo dynamic 99mTc-HIDA scintigraphy was tested as a method for graft function monitoring after hepatocyte transplantation (HTX). Bilirubin uridyldiphosphate glucuronyl transferase-deficient rats received 10(7) viable isolated hepatocytes from congenic nondeficient donors by intrasplenic injection. The transplanted rats were divided into 2 groups. Three months after HTX, one group underwent 99mTc-HIDA scintigraphy, the other was subjected to bile analysis for the detection of bilirubin glucuronides (the presence of which would indicate biochemical activity of transplanted hepatocytes). Histological examination of the spleen of all animals was performed at the end of the experiment. The same experimental protocol was applied to 10 sham-treated enzyme-deficient rats serving as controls. The scintigraphic studies showed that spleens of transplanted rats did accumulate 99mTc-HIDA, this in contrast to sham-treated rats. Furthermore, time-activity curves of liver and spleen of HTX-treated rats showed similar kinetic patterns, suggesting a biologically normal function of the hepatocytes grafted in the spleen. Bilirubin glucuronides were excreted by transplanted rats, not by control rats. Histological examination of the spleen revealed hepatocyte survival in all HTX-treated rats. These findings demonstrated a correlation between increased splenic uptake of 99mTc-HIDA and biochemical activity and morphological survival of intrasplenic donor hepatocytes. In conclusion, in vivo dynamic 99mTc-HIDA scintigraphy appears to be an ideal method for noninvasive graft function monitoring after intrasplenic HTX.
    European Surgical Research 02/1987; 19(3):140-50. · 1.43 Impact Factor
  • Source
    R Leyten, J. P. A. M. Vroemen, N Blanckaert, K. P. M. Heirwegh
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    ABSTRACT: In this paper the production of the R/APfd-j/j strain which is congenic with the R/APfd strain is reported. The R/APfd-j/j completely lacks hepatic bilirubin UDP-glucuronyltransferase activity, as do our GUNNXR/Pfd-j/j rat strain and various other stocks of GUNN rats (j/j) described in the literature. Our recombinant inbred strain GUNNXR/Pfd-j/j was produced from non-inbred GUNN (j/j) rats. This GUNNXR/Pfd-j/j rat was used as a donor of the jaundice gene j, the R/APfd rat serving as the recipient. After eight backcross-intercross cycles (16 generations) the R/APfd-j/j strain was obtained which is congenic with the R/APfd strain. Congenicity was demonstrated by various techniques including transplantation of skin tissue, strain-specific tumour cells and hepatocytes, the mixed lymphocyte reaction, and comparison of biochemical markers. The potential of the novel inbred strain of jaundiced rat, R/APfd-j/j, and the corresponding control strain R/APfd for biochemical and clinical studies of bilirubin metabolism are briefly discussed.
    Laboratory Animals 11/1986; 20(4):335-42. · 0.80 Impact Factor
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    ABSTRACT: Long-term effects of hepatocyte transplantation (HTX) in the treatment of enzyme deficiency disease were studied. Congenic enzyme-deficient (R/APfd-j/j) and non-enzyme-deficient (R/APfd) rats were used as recipients and donors, respectively. The R/APfd-j/j rat strain is congenitally deficient of bilirubin uridyldiphosphate (UDP)-glucuronyl transferase. R/APfd-j/j rats underwent HTX by intrasplenic injection of 10(7) isolated R/APfd hepatocytes (group 1A). Another group of R/APfd-j/j rats was treated similarly, but underwent splenectomy after 11 weeks (group 1B). Controls consisted of R/APfd-j/j rats grafted with 10(7) R/APfd-j/j hepatocytes (group 2), and R/APfd-j/j rats that underwent a sham operation (group 3). Total plasma bilirubin (TB) levels were significantly reduced in groups 1A and 1B during the experiment (both P less than 0.01). In the control groups TB reduction was not observed. Bile analyses at 30 weeks after HTX showed that in group 1A 13.7 +/- 2.7% of total biliary bilirubin was conjugated. In group 1B a significantly lower fraction was conjugated: 6.6 +/- 1.1% (P less than 0.05). Conjugated bilirubin was not found in bile of groups 2 and 3. Histology showed survival of hepatocytes in all spleens of rats of groups 1A, 1B and 2. It is concluded that congenic hepatocytes from R/APfd donors are not rejected after transplantation into the R/APfd-j/j rat, and maintain long-term function. Splenectomy does not abolish, but does reduce, the therapeutic effect significantly, indicating that part of the transplanted hepatocytes maintains function in the enzyme-deficient host liver. The congenic R/APfd-j/j and R/APfd rat strains represent a new animal model for research in metabolic deficiency disease.
    Transplantation 09/1986; 42(2):130-5. · 3.78 Impact Factor
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    ABSTRACT: The inbred, homozygous Gunn rat exhibits unconjugated hyperbilirubinemia due to a hereditary absolute deficiency of bilirubin UDP-glucuronyltransferase activity. The mechanism of action of hepatocyte transplantation (HTX) in the treatment of enzyme deficiency has been investigated in this study. Gunn rats underwent HTX by the injection of isolated hepatocytes from a nondeficient donor rat (Wistar) into the spleen. A transient, statistically significant decrease in total plasma bilirubin (TB) levels was observed. Gunn rats receiving Gunn hepatocytes did not show such a decrease. Histological examination 2-3 months post-HTX of the recipient spleens showed the absence of grafted hepatocytes in the first group and graft survival in the second. Bile specimens from sublethal irradiated Gunn rats, collected 6 days after HTX with viable Wistar hepatocytes, all contained bilirubin mono- and diglucuronides. Control groups consisting of Gunn rats receiving nonviable Wistar hepatocytes or Gunn hepatocytes, and sham-operated Gunn rats did not excrete bilirubin glucuronides in bile. It was also demonstrated that bilirubin UDP-glucuronyltransferase activity, which appeared in Gunn rats after HTX with Wistar hepatocytes, was only transient. It is concluded that the decrease of TB in the Gunn rat after HTX with nondeficient hepatocytes is explained by the appearance of the enzyme, which was absent in the recipient animal. Viable, nondeficient hepatocytes are required for the elicited bilirubin conjugation. Rejection of the transplanted hepatocytes abolishes this effect.
    Journal of Surgical Research 10/1985; 39(3):267-75. · 2.12 Impact Factor
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    ABSTRACT: The influence of warm and cold ischemic time (WIT and CIT) on renal allograft function and allograft survival rates was analyzed from the Eurotransplant data. From 1977 through 1980 renal allograft recipients were divided into three groups, according to the length of the WIT of their graft: group I, 0-10 min (n = 2,636); group II, 11-20 min (n = 108); group III, 21-35 min (n = 17). Differences in graft function or graft survival have not been observed between these groups. It is concluded that donor kidneys with a WIT up to 20 min are acceptable for transplantation. The transplantation results in group III suggest that 35 min is a safe limit for acceptance, but the small number of transplantations in this group does not justify a firm conclusion. A combined analysis of warm and cold ischemia shows that simple cold storage up to 50 h is safe and acceptable, provided that warm ischemia is kept minimal (less than 10 min). It seems advisable to keep hypothermic preservation within the limit of 30 h, when WIT exceeds 10 min.
    European Surgical Research 02/1984; 16(3):175-81. · 1.43 Impact Factor
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    ABSTRACT: The influence of warm and cold ischemic time (WIT and CIT) on renal allograft function and allograft survival rates was analyzed from the Eurotransplant data. From 1977 through 1980 renal allograft recipients were divided into three groups, according to the length of the WIT of their graft: group I, 0–10 min (n = 2,636); group II, 11–20 min (n = 108); group III, 21–35 min (n = 17). Differences in graft function or graft survival have not been observed between these groups. It is concluded that donor kidneys with a WIT up to 20 min are acceptable for transplantation. The transplantation results in group III suggest that 35 min is a safe limit for acceptance, but the small number of transplantations in this group does not justify a firm conclusion. A combined analysis of warm and cold ischemia shows that simple cold storage up to 50 h is safe and acceptable, provided that warm ischemia is kept minimal ( < 10 min). It seems advisable to keep hypothermic preservation within the limit of 30 h, when WIT exceeds 10 min.
    European Surgical Research 01/1984; 16(3):175-181. · 1.43 Impact Factor
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    ABSTRACT: Transplantation results after kidney preservation by means of cold storage and machine perfusion were analyzed. Graft survival and function of 75 machine-perfused kidneys were the same as those of 2,686 kidneys preserved by cold storage. Cold storage, a relatively simple, safe, and inexpensive procedure, was preferred for the preservation of kidneys that had not been subjected to prolonged periods of warm ischemia. Machine perfusion could be used for kidneys damaged by ischemia, although its advantage over cold storage in these circumstances was not firmly established.
    Archives of Surgery 11/1983; 118(10):1166-8. · 4.30 Impact Factor
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    ABSTRACT: It is current practice to only consider heart-beating donors as suitable for organ donation. Patients who have sustained a permanent cardiac arrest are believed to be unsuitable for kidney retrieval, in the knowledge that the kidneys will have received extensive ischemic damage. In situ kidney preservation (ISP), using the double balloon triple lumen (DBTL) catheter, offers the possibility of harvesting valuable kidneys from these, otherwise unsuitable, donors. With this technique human kidneys can be cooled in situ prior to the donor nephrectomy. During ISP, nephrectomy can be performed under optimal surgical conditions. In this report indications for ISP, insertion technique of the DBTL catheter, legal aspects, and transplantation outcome of kidneys harvested by means of ISP are discussed.
    The Netherlands journal of surgery 06/1983; 35(2):55-60.

Publication Stats

320 Citations
33.90 Total Impact Points

Institutions

  • 1984–1993
    • Maastricht University
      • Algemene Heelkunde
      Maastricht, Provincie Limburg, Netherlands
  • 1987
    • Academisch Medisch Centrum Universiteit van Amsterdam
      • Department of Surgery
      Amsterdam, North Holland, Netherlands