Biomedical subjects

Endre Brath

Publications and source records attributed to Endre Brath.

9 recordsLinked to original sources

PubMed2006

Learning microsurgical suturing and knotting techniques: comparative data.

Correctly performed surgical sutures are the basis of surgical safety. This retrospective survey was conducted among participants (n = 263) taking graduate and postgraduate courses between 2000-2004. Placement of sutures, time to perform knotting, safety of knots, and quality of knot stability were tested. None of the students had been previously instructed in microsurgical techniques. At the beginning of the training program, 90-95% of participants damaged the suturing thread at several places. By the end of the course, knotting times significantly decreased in both groups. Graduates decreased their time from 6.8 +/- 2.34 min to 3.28 +/- 0.71 min (mean +/- standard error of the mean), and postgraduates decreased their time from 5.02 +/- 3.25 min to 1.54 +/- 0.54 min (mean +/- standard error of the mean). In our opinion, "mass training" to teach the basics of microsurgery is not a good approach. Instead, individual training should be provided, as tutors offer invaluable advice, and adjust almost each stitch and knot during teaching sessions.

Clinical Competence↗

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↗

PubMed2006

Distribution of peripheral blood cells in mice after splenectomy or autotransplantation.

Our aim was to compare the distribution changes of peripheral leukocytes and erythrocytes in splenectomized and spleen-autotransplanted BALB/c female mice (n = 96), 2 and 8 months after surgery. In total, there were eight groups of animals: splenectomy, autotransplantation, sham, and untreated controls at both time points. We used the spleen-apron method of Furka et al. (Khirurgiia (Mosk) 1989;9:125-127), inserting five spleen chips into the greater omentum, for autotransplantation. Quantitative and qualitative blood cell counts and the phagocytic activity of cells (stimulated with zymosan) were determined. In splenectomized animals, the number of neutrophils significantly increased 8 months after surgery. The greatest phagocytic activity of neutrophils, however, was observed in autotransplanted animals of the same age. In splenectomized animals, erythrocyte volumes were significantly higher in the second postoperative month, but normalized by the eighth month. In conclusion, spleen autotransplantation has some beneficial effects, including clearing erythrocytes and preserving the phagocytic activity of neutrophils in peripheral blood.

Animals↗

PubMed2004

Influence of moderate and profound hyperventilation on cerebral blood flow, oxygenation and metabolism.

OBJECTIVE: The aim of the present study was to examine the impact of moderate and profound hyperventilation on regional cerebral blood flow (rCBF), oxygenation and metabolism. MATERIALS AND METHODS: Twelve anesthetized pigs were subjected to moderate (mHV) and profound (pHV) hyperventilation (target arterial pO(2): 30 and 20 mmHg, respectively) for 30 min each, after baseline normoventilation (BL) for 1 h. Local cerebral extracellular fluid (ECF) concentrations of glucose, lactate, pyruvate and glutamate as well as brain tissue oxygenation (p(ti)O(2)) were monitored using microdialysis and a Licox oxygen sensor, respectively. In nine pigs, regional cerebral blood flow (rCBF) was also continuously measured via a thermal diffusion system. RESULTS: Both moderate and profound hyperventilation resulted in a significant decrease in rCBF (BL: 37.9+/-4.3 ml/100 g/min; mHV: 29.4+/-3.6 ml/100 g/min; pHV: 23.6+/-4.7 ml/100 g/min; p<0.05) and p(ti)O(2) (BL: 22.7+/-4.1 mmHg; mHV: 18.9+/-4.9 mmHg; pHV: 13.0+/-2.2 mmHg; p<0.05). A p(ti)O(2) decrease below the critical threshold of 10 mmHg was induced in three animals by moderate hyperventilation and in five animals by profound hyperventilation. Furthermore, significant increases in lactate (BL: 1.06+/-0.18 mmol/l; mHV: 1.36+/-0.20 mmol/l; pHV: 1.67+/-0.17 mmol/l; p<0.005), pyruvate (BL: 46.4+/-7.8 micromol/l; mHV: 58.0+/-10.3 micromol/l; pHV: 66.1+/-12.7 micromol/l; p<0.05), and lactate/glucose ratio were observed during hyperventilation. (Data are presented as mean+/-S.E.M.) CONCLUSIONS: Both moderate and profound hyperventilation may result in insufficient regional oxygen supply and anaerobic metabolism, even in the uninjured brain. Therefore, the use of hyperventilation cannot be considered as a safe procedure and should either be avoided or used with extreme caution.

Animals↗

PubMed2003

Hematological, hemorheological, immunological, and morphological studies of spleen autotransplantation in mice: preliminary results.

Using a spleen autotransplantation model, we conducted hematological, hemorheological, immunological, and morphological studies in mice 6 weeks after splenectomy. Sixty male and female A/J inbred mice were equally divided into 3 groups: 1) SE group, splenectomy was performed; 2) AU group, spleen chips were autotransplanted into the omentum without vascular anastomosis following splenectomy; and 3) C group (controls), no intervention in these mice. At postoperative week 6, the following studies were performed: 1) measurement of hematological parameters; 2) hemorheological studies, including relative cell transit time (RCTT) and fibrinogen levels; and 3) activity of peripheral phagocytes, measured by zymozan-induced chemiluminescence, which was calculated in stimulation index values (SI). In addition, histological investigations of autotransplants were conducted. Erythrocyte mean cell volume and platelet counts, RCTT, fibrinogen levels, and activity of phagocytes were significantly higher in the SE group, compared to those in the C group. In the AU group, these parameters were similar to those in the C group. Morphologically, the transplanted spleen showed normal histology. These data indicate that the transplanted spleens restored their function. We conclude that spleen autotransplantation reserves the normal morphology of spleen and restores most of the spleen's hematological, hemorheological, and immunological functions. Both SI index and erythrocyte deformability can be an informative detection of decreasing splenic function. These data suggest that spleen autotransplantation may provide a useful tool to prevent complications following splenectomy in a clinical setting.

Animals↗

PubMed2003

Multiorgan transplantation with a new organ-chip technique in mice: preliminary histological data.

A simple model was developed for multiorgan liver-kidney-spleen-intestine transplantation on 108 inbred mice. Donor operations included hepatectomy, nephrectomy, splenectomy, and jejunum segment resection. Following removal of the organ, small slices or abdominal organ "chips" were prepared. During multiorgan recipient operations, chips from each of these organs were transplanted into the omentum; in the control single-organ groups, only 1 organ was transplanted. All animals survived. Biopsies were taken for histology after 6 weeks. All organs were found to have developed a blood supply. In the liver chips, hypertrophied cells could be detected. In the margin of the kidney tissue, both the glomeruli and tubules were preserved. Lymphoid zone and red pulp were intact in spleen chips. All layers of the intestinal chips were identifiable and contained intraluminal mucinous substances. This model is a simple surgical intervention with the possibility of the investigation of 4 organs.

Animals↗

PubMed2003

Changes in microcirculation after ischemic process in rat skeletal muscle.

Laser Doppler flowmetry (LDF) is a good method to investigate tissue microcirculation, but it has many standardization and measuring problems. To exclude these effects, we performed a test using LDF on rat skeletal muscle. In 12 CD outbred anesthetized rats, bilateral femoral vessels and the quadriceps femoris muscle were exposed. The left femoral artery and vein were clamped for 1 h by microvascular clips (ischemic side). On the right side, no other intervention was made (control side). An LDF probe was applied on the medial vastus muscle. Short-term occlusions (2-3 s) were performed before and after the 1-h clamping and on the control side while LDF curves were registered. The halftimes of ascending curves on the ischemic side were significantly elongated vs. the condition before clamping (P = 0.0007) or the control side (P = 0.0017). Microcirculatory changes caused by 1-h ischemia were shown by this simple, quick, and well-reproducible test on rat skeletal muscle.

Animals↗

PubMed2003

Transplantation and microsurgical anastomosis of free omental grafts: experimental animal model of a new operative technique in dogs.

Our objective was the elaboration of a new animal model for the free transplantation of an omental flap and the examination of its viability in dogs. The cooled omental flap from the abdomen was freely transplanted to the lateral cervical region, and its blood supply was established with microsurgical anastomoses. The technique was developed in 5 dogs, and short-term survival examinations were later carried out in 3 cases by means of this method. Postoperative viability was assessed by angiography, methylene blue testing, and histology. Of the 3 transplanted grafts, 2 still survived 1 week after the operation. For technical reasons, 1 flap thrombotized. For determination of the viability of the transplanted graft, histology proved best. Vital reactions, including granulation tissue and angiogenesis, were present on the histological slides. The short-term survival of an omental flap can be ensured with microsurgical transplantation in dogs.

Anastomosis, Surgical↗