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G Klima

Publications and source records attributed to G Klima.

At least 37 records · Page 2Linked to original sources
PubMed1998

[A new method of orthotopic liver transplantation from the guinea pig to the rat].

Guinea pig to rat orthotopic liver transplantation is associated with serious technical problems contributing to impaired graft reperfusion and a high incidence of primary non function. In order to reduce the operation time and thereby organ damage during procurement a simplified technique for reconstruction of the infrahepatic vena cava was developed and is described in detail. Reduced operation time was associated with markedly improved lobular graft perfusion and significantly better graft survival. We suggest a modification of the donor operation for the guinea pig to rat xenograft liver model for the sake of reducing non immunological factors in this difficult setting.

Animals↗
PubMed1997

At what stage does pancreas allograft rejection become irreversible?: an experimental study.

BACKGROUND: It is commonly believed that abnormal blood glucose levels indicate irreversible rejection. We were interested in determining the stage at which rejection remains reversible. METHODS: A total of 54 Lewis rats were rendered diabetic with 55 mg/kg streptozocin and were then given a pancreas transplant from Brown Norway donors. Pancreatic juice was collected in a subcutaneous reservoir. All recipients received 15 mg/kg cyclosporine A (CsA) for 5 days. CsA was then discontinued for 2 days (n=7, group 1), 4 days (n=7, group 2), 6 days (n=9, group 3), 8 days (n=9, group 4), 9 days (n=11, group 5), and 10 days (n=11, group 6). Two animals of each group were euthanized at the end of the immunosuppressive-free interval, for histological assessment of the grade of rejection (G0, GI, GII, GIII). Rejection was treated with methylprednisolone (7 mg/kg body weight) and CsA (15 mg/kg body weight). The volume of pancreatic juice, together with juice cytology (C0, CI, CII) and blood glucose levels, was assessed daily. RESULTS: Blood glucose remained normal throughout the observation period in animals with GI and GII rejection. The numbers of animals that became diabetic were as follows: 5 of 9 (group 4), 7 of 11 (group 5), and 8 of 11 (group 6). Decreased amounts of pancreatic juice were observed in all animals, except those in group 1. The histology returned to normal after anti-rejection therapy in four animals (57%) of group 1, in two animals (28%) of group 2, and in one animal (11%) of groups 3 and 4, respectively. Although there was no animal in groups 5 and 6 with normal graft histology after treatment, there were still four (36%) and three (27%) animals, respectively, that were normoglycemic and that had pancreatic grafts with well-preserved islets. CONCLUSIONS: From these data, we conclude that even GIII rejection with severe endothelialitis and isleitis can be reversed. Therefore, we suggest that a trial of enhanced immunosuppression is justified in patients with advanced pancreas allograft rejection.

Animals↗
PubMed1996

Anatomy and innervation of the rhabdosphincter of the male urethra.

The striated sphincter of the male urethra and its innervation are still a subject of controversy. Essentially, two concepts of its anatomy can be found in the literature. Some authors describe the rhabdosphincter as part of the urogenital diaphragm caudal to the prostate, others as a striated muscle which extends from the base of the bladder to the "urogenital diaphragm." In a combined anatomic-histologic study the striated sphincter and the pudendal nerve were examined by means of anatomical dissections and serial anatomical as well as histological sections of 12 male pelves. Furthermore, radical prostatectomy was performed in a cadaver specimen; subsequently, the so-called "urogenital diaphragm" was excised and then examined histologically. The varying number of striated muscle fibers caudal to the prostate is of particular interest. In fetuses, there are abundant striated muscle fibers dorsal to the membranous urethra, where they are arranged as a circular collar around the urethra. In the adult male, hardly any striated muscle fibers can be found dorsal to the urethra; in a majority of cases this region is devoid of striated muscle fibers. Inserting dorsally in the perineal body, the fibers form an omega-shaped loop around the anterior and lateral aspects of the membranous urethra. The existence of a "urogenital diaphragm" and a strong, circular, striated "external sphincter urethrae" completely encircling the urethra caudal to the apex of the prostate could not be confirmed by our anatomical and histological investigations. Our study shows that the striated muscle fibers run in a cranial direction from the bulb of the penis to the base of the bladder along the anterior and lateral aspects of the prostate and the membranous urethra. Further dissection studies revealed that the rhabdosphincter is supplied by branches of the pudendal nerve after leaving the pudendal canal.

Aged↗
PubMed1996

Comparison of different modes of high-frequency ventilation in surfactant-deficient rabbits.

Various modes of high-frequency ventilation (HFV) have been developed to avoid the disadvantages of conventional mechanical ventilation. In the present study, we examined the hypothesis that high-frequency oscillation (HFO) is superior to high-frequency positive pressure ventilation (HPPV) and combined high-frequency ventilation (CHFV) in surfactant-deficient rabbits. The aim of the ventilator strategy was to adjust the mean airway pressure to 2 cm above critical opening pressure of the inflation limb of the respiratory system pressure volume (P/V) curve, achieve a normal tidal volume (VT) (5 ml/kg body weight) and apply repeated sustained inflations. We studied the effect of these HFV modes on oxygenation, lung mechanics and lung histology in 15 New Zealand White rabbits during a 6-hour experiment. Statistically, the HFO group demonstrated significantly better oxygenation (P < 0.05), lung mechanics (lung stability index: P < 0.05), and better lung tissue histology compared to the HPPV and CHFV groups. In contrast to the HPPV and CHFV groups, the P/V curves of the HFO group showed significant recovery over the 6-hour period after lavage. The lungs of the HFO-treated group had a more uniform distribution of alveoli and less overdistention than the HPPV group (P < 0.002), and less atelectasis than the CHFV group (P < 0.05). The HFO group had less lung injury than the CHFV groups (P < 0.01) and its lungs contained significantly less water than both other groups (P < 0.05). We conclude that the relationship between mean and end-expiratory pressures impacts strongly on both oxygenation and the progression of injury during HFV at the same mean airway pressures. The HFO group showed less acute lung injury than the other ventilatory groups.

Animals↗
PubMed1996

The interface between ionomer cement and bone in the porcine cervical spine.

The interface between bone and ionomer cement has been studied in twelve young adult pigs 1-6 months after anterior cervical discectomy, removal of adjacent end plates and grafting of the bone defect with ionomer cement. Methods used to study the interface were fluorescence microscopy, scanning electron microscopy, electron microprobe analysis and radiological investigation. The interface in all animals consisted of collagenous tissue. The amount of collagenous fibres was related to the amount of residual movement within the motion segment: animals undergoing anterior plating after reconstruction of the bone defect presented with more or less compactly organized collagenous tissue. Sequential fluorochromic marking of osteoid formation revealed a vital bone bed around the interface but no signs of direct bone apposition to the ionomer cement plug. No signs of toxicity or graft rejection were noted. Ionomer bone cement contrary to experimental and clinical experience induces the formation of a connective tissue layer of different density in the porcine cervical spine.

Animals↗
PubMed1996

Simultaneous transplantation of isolated hepatocytes reduces rejection of small bowel allografts and improves survival in the rat.

Hepatocytes transplanted some days prior to vascularized allografts were shown to have the potential to prolong allograft survival in the rat. In the present study, hepatocytes and small bowel allografts were transplanted simultaneously in a Lewis (donor)-Brown Norway (recipient) rat model. 8-15 x 10(6) liver cells were injected into the spleen of small bowel recipients. The administration of at least 10 mg cyclosporine A (CyA)/kg over 3 days was necessary to prevent early rejection of hepatocytes. In groups simultaneously receiving hepatocytes, small bowel grafts and 10 mg CyA/kg over 3 days, a significant mitigation of rejection and a prolongation of survival was achieved, compared to groups receiving solely small bowel grafts and 10 mg CyA/kg over 3 days. We conclude that simultaneously transplanted hepatocytes exert a protective effect on a grafted organ from the same donor, provided that early rejection of hepatocytes is prevented by sufficient immunosuppression.

Animals↗
PubMed1996

Definite distinction between thyroidal inflammatory conditions and other soft tissue inflammations of the neck using ultrasound.

Thyroid and non-thyroid inflammations are acute conditions accompanied by severe pain. It is impossible for general practitioners who have to refer patients to various outpatients department or specialised hospitals to distinguish between these conditions, even with the help of medical history, palpation and findings of laberatory investigations. Therefore, patients are often falsely referred to nuclear medicine or ENT outpatient departments. With the help of ultrasound a definite distinction between inflammatory conditions of the thyroid and other soft tissue inflammations of the neck can be established.

Abscess↗
PubMed1995

The impact of jejunal transplant peristalsis on enteric flora.

The importance of phase III of the migrating myoelectric complex (MMC) for homeostasis of enteric flora is well documented. The goal of this study was to evaluate in an isogeneic rat model the effect of MMC changes on the self-purging capacity of the jejunal graft. The proximal 25% of the entire jejunoileum of Lewis rats was transplanted orthotopically. Electrodes were then fixed to the graft. Native bowel of five rats and five rats with analogue jejunal segmentation served as controls. Myoelectric recordings were carried out until day 21, when animals were killed for bacteriologic analysis of the segments analyzed myoelectrically and the of neighboring gut. MMCs were observed in all animals during all recordings. Phase III was irregular in transplants because of long-lasting periods of phase III absence alternating with phase III occurring more frequently. The variation coefficient of phase III periodicity calculated for grafts was 48.74, for native bowel 14.79, and for segmented jejunum 22.9. Enteric flora found in all specimens consisted of colonic-like microorganisms. Titers of microorganisms in grafts did not differ from control segments. These findings show that phase III periodicity is severely altered in jejunal grafts. Homeostasis of enteric flora, however, is not influenced by the transplant procedure.

Animals↗
PubMed1995

Considerations and problems in the development of the mini-spindle pump.

The premise for the development of the mini-spindle pump, planned as an implantable device for assisted circulation, was to transport 4 L of water/min in mock circulation with a speed of 12-15,000 rpm against an afterload of 90 mm Hg. After calculations, the resulting first prototype had a spindle rotor with 3 threads (outer diameter, 18 mm; inner diameter, 6.2 mm; length, 45 mm) in a U-shaped housing, driven by an electric motor with a cooling system. In mock circulation, this pump moved 7.8 L of water/min at 18,000 rpm. To avoid animal experiments, its influence on the blood was tested in a Maxima oxygenator. The device circulated 4.2 L of blood/min with the same speed. Because of its high traumatic hemolysis rate (> 250 mg% of free hemoglobin after 7 h of pumping), the rotor was modified, first without effect at 2.5 threads and then at 4 threads. In addition, in this third prototype, the flow direction was reversed. This prototype was more effective (4.3 L of blood/min at 12,000 rpm in the oxygenator) and the hemolysis rate, after a pumping duration of 8 h, could only be reduced to 180 mg% of free hemoglobin. As a result, a fourth prototype was developed (i.e., the U-shape of the housing was abandoned). This device functioned better than the third prototype (4.5 L of blood/min at 12,000 rpm in the oxygenator), but the blood trauma increased (220 mg% of free hemoglobin after 7 h of pumping).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Myoelectric activity during small bowel allograft rejection.

The effect of rejection on myoelectric activity of an orthotopically transplanted small intestinal segment (group I, N = 14) was studied. Electrodes were placed on grafts and recipient small bowel. Isografts (group II, N = 5) and native bowel (group III, N = 5) served as controls. The first morphological signs of rejection were seen on day 6 and steadily progressed until day 11, when the cellular infiltrate involved all layers of the bowel wall. Slow-wave frequencies remained unchanged throughout the observation period. No difference was detectable between grafts (group I: 31.9 +/- 1.65; group II: 31.36 +/- 0.7) and native bowel after transection (group I: 32.16 +/- 1.78; group II: 31.50 +/- 1.01), which was different (P = 0.0001) from intact bowel of group III animals (38.4 +/- 0.81). Irregular MMCs were detectable in grafts from day 5 on and replaced after food intake by random spiking activities. At day 8, spiking activities disappeared in allografts, which showed a still preserved mucosal architecture, while slow-wave activities continued. These findings demonstrate that intestinal allografts during rejection develop paralysis before mucosal destruction is established, which might be of clinical relevance.

Action Potentials↗
PubMed1994

Early diagnosis of fat embolism syndrome by automated image analysis of alveolar macrophages.

To evaluate the value of automated semiquantitative analysis of fat within alveolar macrophages as an early diagnostic tool for fat embolism syndrome (FES), we investigated 3 patients with respiratory failure following long-bone fractures. The mean area of fat droplets per alveolar macrophage was determined in pixels and, additionally, the percentage of the evaluated areas was calculated. In 2 patients, the diagnosis of FES could be established as early as 24 hr after trauma. Both patients showed an increase in the area of fat per alveolar macrophage (pixels: 851, 1069) as well as in the percentage of fat area per alveolar macrophage area (40.04%, 52.73%), whereas the analysis of the bronchoalveolar lavage (BAL) specimens of a third patient, who later recovered without appearance of clinical signs of FES, revealed only minimal fat content (pixels: 82; 3.82%). Automated semiquantitative analysis of fat within alveolar macrophages may be helpful in the early diagnosis of FES.

Embolism, Fat↗
PubMed1993

[Hemorheologic effects of ginkgo biloba extract EGb 761. Dose-dependent effect of EGb 761 on microcirculation and viscoelasticity of blood].

METHOD: In a randomized open clinical trial involving 42 patients with pathological visco-elasticity values, the effect of a single intravenous injection of 50, 100, 150 or 200 mg of the Ginkgo biloba extract EGb 761, commercially available as Tebonin p.i. on the microcirculation of the skin (Doppler flowmetry) and the visco-elasticity of whole blood was investigated. RESULTS: A dose-dependent significant increase in the microcirculation was found. In the case of visco-elasticity, this dose-dependence was less marked. The present study thus confirms the positive effect of EGb 761 on the microcirculation and whole-blood visco-elasticity in patients with pathological visco-elasticity values, already found in earlier studies, and shows it to be dependent on the dose employed.

Aged↗
PubMed1993

The pattern of rejection after combined stomach, small bowel, and pancreas transplantation in the rat.

This study was designed to investigate whether in combined stomach, small bowel, and pancreas transplantation allograft rejection occurs in the individual organs concomitantly and with the same intensity. Heterotopic en-bloc transplantation of the stomach, small bowel, and pancreas was performed in a Lewis-to-Brown Norway rat combination. Group 1 animals received no immunosuppressive therapy while animals in group 2 were treated with cyclosporin (10 mg/kg body weight, orally) daily. Grafts were histologically evaluated on the 5th (subgroups 1a and 2a) and 10th (subgroups 1b and 2b) postoperative days. The degree of rejection was defined as moderate, intermediate, or severe according to predefined criteria. The results indicate that the small bowel is more susceptible to rejection than either the stomach or the pancreas. Mucosal biopsies of the stomach are unlikely to provide a reliable guide to rejection in the small bowel.

Animals↗
PubMed1993

Increase in intraepithelial lymphocytes as an early marker of rejection in a fully allogeneic rat small bowel transplantation model.

In a model of fully allogeneic heterotopic rat small bowel transplantation, the changes in intraepithelial lymphocyte (IEL) number and subpopulations were analysed. During early phases of rejection (5th postoperative day) a 4-fold increase in the number of IEL was observed when compared with native small bowel (4.05 vs. 15.84 IEL/100 epithelial cells). When cyclosporine was given, counts were still as high as 11.4 and 12.58 on the 5th and 10th postoperative days, respectively. The percentage of CD8+ IEL, constituting a major population (84%) in the untreated small bowel, was significantly decreased (46.4%) during early phases of rejection. At that time, the majority of intraepithelial mononuclear cells were both CD8- and CD4-. In cyclosporine-treated animals, this was not observed until the 10th postoperative day. Some 23% of IEL in untreated animals expressed MHC class I antigens of the host; 17.2% (5th postoperative day) and 19.8% (10th postoperative day) did so in the cyclosporine-treated animals. Transmission electron microscopy revealed lymphocytes that bore cytoplasmic buds and pseudopods protruding between the enterocytes. There was no morphological difference between the IEL of rejected allografts and native small bowel. Due to the unspecific histologic changes associated with rejection, interpretation of histopathologic findings in mucosa biopsies of the allograft can be rather troublesome. An increase in the number of IEL is therefore a welcome additional marker of rejection.

Animals↗