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Katalin Peto

Publications and source records attributed to Katalin Peto.

10 recordsLinked to original sources
PubMed2006

Measurement of erythrocyte deformability and methodological adaptation for small-animal microsurgical models.

Measuring erythrocyte deformability with bulk filtrometers is common, but there are problems with standardization and sample quantity in small laboratory animals. In this study, blood was drawn from mice, rats, and dogs, and then erythrocyte suspensions at 1-5% hematocrit were prepared. Bulk filtrometers with a 5- or 3-microm pore-diameter filter were used to determine the initial relative filtration rate (IRFR) and relative cell transit time (RCTT). Hematological composition was also tested. In all species, the highest IRFR values occurred at 1% hematocrit, and the lowest values at 5%. In mice and rats, RCTT values were lowest at 1% and highest at 5% using a 5-microm filter, whereas in dogs, RCTT was elevated at 1-2%. Using a 3-microm filter, each species showed the same phenomena under 3%. RCTT values may become distorted above a certain cell-size/pore-size ratio. In mice and rats, 1% suspension is applicable for bulk filtrometry, but only using 5-microm filters.

Animals↗
PubMed2006

Hemorheological follow-up after splenectomy and spleen autotransplantation in mice.

We previously reported on a spleen autotransplantation model in mice, with spleen function studies at 6 weeks. The present study was undertaken to investigate long-term hemorheological functions. A/J and BALB/c inbred mice were divided into four groups: control, sham surgery (SH), splenectomy (SE), and spleen autotransplantation (AU). Hematological and hemorheological parameters were determined. Leukocyte counts in the SE and AU groups were significantly higher than in controls, while hematocrit levels were markedly lower. Mean erythrocyte volume did not change significantly. Platelet counts in the AU group were significantly lower, and red blood cell deformability was significantly worse in the SE group. The AU group also had increased cell transit time, but it was less than that in the SE group. The SE group showed the highest fibrinogen levels. We conclude that there are some consistent differences in hematological parameters between splenectomy and spleen autotransplantation. These data suggest that spleen autotransplantation may partially restore hemorheological functions following splenectomy.

Animals↗
PubMed2005

[Can the injured spleen be preserved? Results of 20-year experiments].

Researches of different spleen salvaging techniques have begun in 1986 at our department. The early purpose was to develop new spleen preservation surgical techniques, such as spleen autotransplantation and spleen resection. Besides the morphological and radiological examinations we also performed different investigations including hemorheological, hemostaseological and immunological follow-up of the splenic function. From these parameters changes in red blood cell deformability and peripheral phagocyte activity could indicate the possible complications originated from the reduced splenic function. Recent paper takes a survey of these experiences.

Animals↗
PubMed2005

[The role of pneumoperitoneum and the "chimney effect" on the development of port site metastasis. A new experimental animal model using Furka's spleen tissue suspension].

Following the introduction of laparoscopic cholecystectomy, laparoscopic technology has been applied in many other fields of surgery, including surgery for malignancies, even before prospective, randomised trials were available. Many authors observed development of port site metastases following laparoscopic surgery in malignancies (1-2%). The studies report about the pathomechanism of the development of port site metastasis, some describe the role of pneumoperitoneum. We developed a new model to show the role of pneumoperitoneum and the "chimney effect" on the development of port site metastasis, using a large experimental animal with a suspension of its own spleen tissue. On follow up histology viable spleen tissue was found between the layers of the trocar incisions.

Abdominal Neoplasms↗
PubMed2005

[Laparoscopic versus open cholecystectomy: reaction in the liver bed].

The aim of this study was to compare the incidence, size and localisation of adhesion formation following open and laparoscopic cholecystectomy and to determine immune and foreign body reactions in the liver bed. The experimental animals were divided into two groups: open (OC) versus laparoscopic (LC) cholecystectomy. In the 14th postoperative day the animals were reoperated, types and size of adhesion were measured and tissue samples were extracted from the liver bed for histology. Dense, curtain-like adhesions were formed in OC group. The adhesions developed not only in the operation area but also on other organs. The thread used to ligate the cystic duct and cystic artery caused foreign body reaction, which resulted in granuloma formation. Numerous macrophages, histiocyte giant cell reactions were also present in OC group. Considerable fibrosis was also observed in the majority of the animals. Slender adhesion formation formed after LC. It was mostly detected in the liver bed. Foreign body granulomas around the laparoscopic clips did not develop in the cases. Moderate inflammatory reactions were noticeable. Laparoscopic operative technique is less traumatic. Its advantage over the open technique is lower adhesion rate and better immune function and reaction. This operation technique is less immunosuppressive and development of adhesions is less compared to OC.

Abdomen↗
PubMed2005

[Intraoperative laser doppler flowmetry of the tissue microcirculation of extraperitoneal transplanted omental flaps on dogs].

The aim of this study was to develop a new method to check of the viability of an extraabdominally transplanted omental flap. We performed free omental transplantation to the left lateral neck region in the frame of a formerly published new esophageal resection series on 5 dogs. Intraoperative laser Doppler flowmetry was performed, before and after isolation, after transplantation, and 14 days after the operation. From the 5 transplanted flaps, 4 survived the transplantation. The flap microcirculation deteriorated immediately after the transplantation, but at the time of re-operation the measurements showed similar microcirculation as control tissues, which proves the viability of the transplanted flaps. In our opinion, in dogs for the intraoperative monitoring of viability and microcirculation of free transplanted omental flaps, laser Doppler flowmetry is a feasible method.

Animals↗
PubMed2005

[Kidney neovascularization by the greater omentum after pretreatment with omental angiogenic factor].

BACKGROUND: Several diseases may affect the renal artery and the circulation of the kidney. In these cases alternative blood flow should be secured to preserve renal function. There are experimental methods for this, such as omentonephropexy. In this model the new vessels grow into the kidney from the omentum. METHODS: Thirty mongrel dogs were anaesthetized and operated on. The left kidney was exposed, partially decapsulated, then omental angiogenic factor extractum was placed on the renal surface and the greater omentum was fixed there. After 4 weeks the left renal artery was ligated, and further 4 weeks later the right kidney was removed. Hematology tests were performed, urea, creatinine levels were measured and urine samples were tested after each operations. For statistical analysis Mann-Whitney rank sum and Wilcoxon signed rank tests were used. RESULTS: The survival rate was 20%. Significant elevations were observed in serum creatinine and urea levels after each operation, mostly after the third one and in non-surviving animals. Moderate anaemia was also present. CONCLUSION: The efficacy of the neovascularization presented in this study and the survival rate indicate further investigations are necessary in order to explore the mechanism and the dynamics of the vascularization processes.

Angiogenesis Inducing Agents↗
PubMed2005

[Determination of urinary NAG to detect renal ischemia-reperfusion injury and the protective effect of Allopurinol].

We analysed the effect of ischemia-reperfusion injury to renal parenchyma after unilateral renal artery clamping using urinary N-acetyl-beta-D-glucosaminidase (NAG) that is a sensitive parameter of early renal tubular injury. In the study 60 mongrel dogs were divided into 3 groups: in the 1st group the left renal artery was clamped for 45 minutes, in the 2nd group Allopurinol was administered before the clamping, the 3rd was the control group, where only laparotomy and closure of the abdomen was performed. Urinary NAG activity referring to urinary creatinine (NAG index) was determined before the operation, at the beginning of the reperfusion, in the 60th and 120th minute of the reperfusion then 1, 2, 3 and 5 days after the operation. The highest NAG indices relating to injury of the proximal tubuli were found at the beginning of the reperfusion, in the 60th and 120th minutes of the reperfusion, then NAG returned to preoperative level in each group. Significantly higher NAG indices were found in the ischemia-reperfusion group compared to the group with Allopurinol pretreatment. Renal ischemia-reperfusion injury and the protective effect of Allopurinol could be detected by lysosomal NAG enzyme. The injury of the tubular function was reversible so it could be a change in tubular function.

Acetylglucosaminidase↗
PubMed2005

[The importance of hemorheological examinations in experimental limb ischemia-reperfusion injuries].

Rheological properties of the blood are determined by several factors and if they change it may be diagnostic for many diseases. It is well-known that during ischemia and reperfusion different free-radical liberating pathways are inducted besides the local physical and metabolical changes. These processes may harm red blood cells by increasing their rigidity and impairing their deformability. In ischemia-reperfusion models measurements of erythrocyte deformability is important. Characteristic alterations were observed in both rat and dog hind limb ischemia-reperfusion with vascular clamping on femoral vessels for 1 or 3 hours. Erythrocyte deformability was significantly impaired on the postoperative 1st-3rd days. The acute limb ischemia-reperfusion experimental models seem suitable for further in vivo rheological studies.

Animals↗