Mikrothrombosierung der Endstrombahn als Ursache schockbedingter Organkomplikationen (unter besonderer Berücksichtigung der Schocklunge)

Der Kreislaufschock stellt ein akutes generalisiertes Versagen des Kreislaufs, insbesondere der Kreislaufperipherie mit oder ohne Blutdruckabfall und Gewebsschädigung durch Sauerstoffmangel dar. Kausalpathogenetisch sind Sauerstoffmangel, Endotoxinämie, Komlementfaktoren, vasoaktive Amine und Prostaglandine in einem noch nicht vollständig bekannten Zusammenspiel mit einer Mikrothrombose verantwortlich zu machen. Bezüglich der Organmanifestation des Schocks steht die Schocklunge als Krankheitsbild der modernen Intensivmedizin im Vordergrund. die sich klinisch als acute respiratorische Insuffizienz mit einer Perfusions und Diffusionsstörung für Sauerstoff, einer vermehrten Totraumventilation, einem vermehrten Shunt-Volumen und einer vermehrten Atmungsarbeit äuβert. Der pathologische Vorgang der Schocklunge verläuft biphasisch, beginnt mit einer exsudativen Alveolities und endet über eine sklerosierende Alveolitis in einer alveolären Fivrose, welche therapeutisch kaum mehr zu beherrschen ist. Diagnostisch und fur das weitere therapeutische Procedere entscheidend ist die exsudative Alveolitis. Sie kann in allen phasen der Schocklunge vorkommen oder wieder auftreten. Von ihrer Eindämmung hangt das weitere schicksal des Patienten ab.

The clinical impact of magnetic resonance imaging in fetuses with central nervous system anomalies on ultrasound scan

OBJECTIVES

Magnetic resonance imaging (MRI) was performed on fetuses with sonographically diagnosed central nervous system (CNS) anomalies to determine frequency and type of cases in which fetal MRI adds clinically relevant information.

PATIENTS AND METHODS

Forty-three cases presenting with CNS anomalies by ultrasonography were investigated by MRI. The potential effect of MRI on parental counseling and pre- or postnatal management were the main endpoints.

RESULTS

Fetal MRI confirmed the sonographic diagnosis in 28 of 43 cases, showed additional findings in 14 of 43 cases, and was inferior to sonography in 1 of 43 cases. The MRI diagnosis had therapeutic consequences in 11 of 43 patients, with the fetal MRI diagnosis influencing parental counseling in 8 of these 11 patients. Prenatal patient care was not influenced by the additional investigation with fetal MRI.

CONCLUSION

MRI is well suited as additional imaging method in fetuses with CNS anomalies. Additional fetal MRI is particularly indicated if the findings might have a therapeutic consequence.

Prenatal magnetic resonance imaging as a useful adjunctive to ultrasound-enhanced diagnosis in case of a giant foetal tumour of the neck

Large cervical masses in the prenatal period are rare and can cause life threatening situations after birth. All available diagnostic techniques should therefore be used to determine the best mode of delivery in the case of such malformation. A large cervical mass was detected by ultrasound in a 41-year-old women, gravida 4, para 3, at 29 + 5 weeks of gestation. US imaging was most consistent with the diagnosis of a large cervical teratoma, but it was not possible to sufficiently evaluate the cervical anatomy of the oropharynx and trachea. An MRI scan demonstrated a distorted oropharynx and a trachea displaced to the right and posteriorly, but not detectable from the middle of the neck up to the larynx. Based on these facts, an EXIT procedure was planned and performed at 30 + 5 weeks of gestation. Foetal MRI provided valuable anatomical information for all specialists deciding on the indication and the pre-therapeutic planning of the EXIT procedure.

Prenatal diagnosis of the Meckel-Gruber syndrome from 11th to 20th gestational week

INTRODUCTION

The Meckel-Gruber syndrome (MKS) is a rare autosomal recessive disorder that is characterized by typical sonographical findings: occipital encephalocele, postaxial polydactyly and cystic enlargement of the kidneys. Its recurrence risk of 25 % demands an exact diagnosis.

METHOD

Retrospective analysis of the sonographic characteristics in relation to the gestational age in eight cases with the pathologic diagnosis of MKS.

RESULTS

The sonographic characteristics depend on the gestational age. The classic trias was solely seen in the case diagnosed before 14 (th) week of gestation. In the other seven cases, diagnosed between the 17 (th) and 20 (th) week of gestational age, only two of three characteristic signs of MKS could be visualised by US. Polydactyly was missed by ultrasound in all seven cases due to the marked oligohydramnion.

CONCLUSION

The Meckel-Gruber syndrome can be confidently detected and diagnosed by sonography at the 11th to 14th gestational week. Later in the pregnancy, severe oligohydramnion makes it more difficult to establish the diagnosis by US alone. In these cases a meticulous autopsy is necessary to establish the diagnosis of MKS.

Fetal skeletal deformities - the diagnostic accuracy of prenatal ultrasonography and fetal magnetic resonance imaging

OBJECTIVE

To evaluate the diagnostic accuracy of prenatal ultrasonography and fetal magnetic resonance imaging (MRI) in fetuses with skeletal deformities (SD).

METHODS

Fourteen pregnant women of 21 - 34 weeks of gestation whose fetuses had SD on prenatal ultrasound (seven fetuses with spina bifida, four with complex malformation syndrome, two with scoliosis, and one with chondrodysplasia) were additionally investigated by fetal MRI using a 1.5T superconducting system with T1-and T2-weighted sequences in three section-planes. Main outcome measures were diagnostic accuracy, potential effect on parental counselling and influence on perinatal management of the additional investigation with fetal MRI.

RESULTS

In 10 cases ultrasound had a better diagnostic accuracy than MRI concerning the diagnosis of SD. In four cases with spina bifida MRI provided additional information towards preoperative evaluation for neurosurgery. In five cases parental counselling was improved. There was no influence on perinatal management.

CONCLUSION

MRI may provide additional information to ultrasound scan in fetuses with spina bifida and consecutive neurosurgery; in fetuses with other skeletal deformities additional information may be expected only in rare cases.

Foetal facial clefts: prenatal evaluation of lip and primary palate by 2D and 3D ultrasound

INTRODUCTION

To examine whether three-dimensional ultrasound (3D US) is an accurate diagnostic method of clinical use in the ability to define the location and extent of facial clefting prenatally, compared to two-dimensional ultrasound (2D US).

METHODS

18 foetuses suspected or diagnosed to suffer from a facial cleft by 2D US were examined with a targeted 3D US. 2D US and 3D US results were compared with postnatal outcome.

RESULTS

Comparison of the number of foetuses with a cleft lip + primary palate diagnosed correctly with 2D US with the results of adjunctive 3D US (true positive + true negative) showed that adjunctive 3D US correctly diagnosed more cleft lips (100 %; 15/15 foetuses vs. 66 %; 12/18 foetuses) and more cleft primary palates (100 %; 12/12 foetuses vs. 58 %; 7/12 foetuses).

CONCLUSION

Interactive review of standardised 3D multiplanar images allows to systematically evaluate lip defects and abnormalities of the maxillary tooth-bearing alveolar ridge. The accuracy of adjunctive 3D ultrasound is superior to 2D ultrasound alone for extensive prenatal diagnosis of cleft lip with or without cleft primary palate.

Prenatal diagnosis of a giant foetal lymphangioma and haemangiolymphoma in the second trimester using 2D and 3D ultrasound

Lymphangiomas are benign tumours of the lymphatic system. Early prenatal diagnosis is important to permit a planned delivery and provide adequate postnatal care. It thereby improves prognosis and allows the option of terminating the pregnancy if poor outcome is predicted. We report two cases, a giant haemangiolymphoma and a lymphangioma. 2D and 3D US findings are presented and differential diagnosis, therapeutic options and prognosis are discussed.

Magnetic resonance imaging in foetuses with bilateral moderate ventriculomegaly and suspected anomaly of the corpus callosum on ultrasound scan

OBJECTIVE

The diagnosis of anomalies of the corpus callosum (ACC) in foetuses with bilateral moderate ventriculomegaly (BMV) is difficult by means of ultrasound scan. The aim of this study was to examine the value of the additional investigation with magnetic resonance imaging (MRI) in foetuses with BMV and suspected ACC on ultrasound scan. Pathogenesis and clinical presentation of BMV and ACC are discussed.

METHODS

41 foetuses with central nervous system (CNS) anomalies on ultrasound scan were assessed by ultrasonography and MRI from 1999 to 2001. Eight of these 41 foetuses presented with BMV and suspected ACC on ultrasound scan and were prospectively included in the study. Foetal investigations with sonography and MRI were analysed with regard to diagnostic confidence; results were correlated with post partum findings. Six of these 41 foetuses presented with BMV without suspected ACC on ultrasound scan and were retrospectively analysed.

RESULTS

Ultrasonography suspected ACC in 8 foetuses with BMV. MRI confirmed the presence of ACC in 4 of these 8 cases. MRI additionally showed ACC in two of the six retrospectively analysed foetuses with BMV without suspected ACC on ultrasound scan. Prenatal MRI diagnosis was confirmed after delivery in all cases.

CONCLUSION

MRI is more sensitive than ultrasonography in the evaluation of ACC in foetuses with BMV. For prenatal screening ultrasound still remains the investigation of choice.

Prenatal diagnosis of a de novo inversion of chromosome (2)(p21q11)

Prenatal diagnosis of "apparently balanced" chromosomal rearrangements, if not inherited from a parent, are problematic for genetic counsellors and families. Although the parents need to be informed about the increased risk of multiple congenital anomalies, the anomalies that the fetus is at risk can not be discussed unless a similar breakpoint and accompanying phenotype have been reported in the literature. In the reported case prenatal ultrasound examination revealed a massive hydrocephalus internus and IUGR. The karyotype of the fetus was inv(2)(p21q11) de novo. Postmortem examination revealed short palpebral fissures, hypertelorism, atypical nasiolabial configuration, microgenia, extended position of the fingers, atypical proximal inserted first toe, hydrocephalus internus, hypoplasia of the cerebellum and bulbi olfactorii, bilateral hypoplastic lungs, atrial septal defect II, small right ventricle, dysplasia of the pulmonary valve, hypoplastic pulmonary artery, right proximal ureterostenosis, hypoplastic gall bladder. This is the first description of a de novo inversion (2)(p21q11) in a fetus with multiple malformations.

[Pathology of implants]

Progress in the surgery of implants and biomaterials can be accomplished by: 1. Painstakingly analysing and registering of defaulting implants after explantation within a "National Registry of Implant Pathology". 2. Development of a DNA-microarray named "Implantat/Chronic Wound" in order to discover the differential transcriptional activities of cells brought into contact with different foreign surfaces. 3. Predictive cell-engineering combined with custom-made implant surfaces with the aim of optimal patient care.

Fetal ovarian cysts: development and neonatal outcome

INTRODUCTION

The aim of the study was to evaluate the outcome of fetal ovarian cysts in relation to their size and ultrasonic appearance.

METHODS

We retrospectively analysed pre- and postnatal charts of 61 infants with a prenatal diagnosis of ovarian cysts between 1991 and 2000.

RESULTS

In a total of 61 fetuses 65 ovarian cysts were detected by transabdominal ultrasound: 35 (57 %) cysts on the left side, 22 (36 %) on the right side and 4 fetuses (7 %) had bilateral cysts. Three patients with uncomplicated cysts were lost to follow-up and one fetus with bilateral cysts died in the 27th week of gestation. In 17 cysts treatment was necessary. 14 cysts (all complicated) were operated after delivery because of persistence or enlargement. The histological results were either follicular or theca lutein cysts in 12 cases, one lymphangioma and one teratoma. Two cysts were aspirated in utero and one after delivery. In the remaining 40 fetuses, 43 cysts where only controlled by ultrasound. 8 cysts regressed before delivery and 35 cysts after delivery independent of their sonographic appearance. The mean diameter of cysts that required treatment was significantly different from the mean diameter of cysts that resolved spontaneously (6.8 [SD 2.4] cm vs. 3.3 [SD 0.8] cm; p < 0.01).

CONCLUSION

Complicated cysts which do not regress should be treated either by laparotomy or laparoscopically after delivery. Uncomplicated cysts which exceed 5 cm could be treated by in utero aspiration or aspiration after delivery to avoid further complications. Cysts smaller than 5 cm, presenting the tendency to regress, should be left untouched independent of their sonographic appearance.

Inhibition of TNF-alpha induced cell death in human umbilical vein endothelial cells and Jurkat cells by protocatechuic acid

The Chinese herb radix Salviae miltiorrhizae (RSM) is used in traditional Chinese medicine as a treatment for cardiovascular and cerebrovascular diseases. Several components of the plant extract from salvia mitorrhiza bunge have been determined previously, one of which is protocatechuic acid (PAC). It has been found, in the study, that PAC inhibited TNF-alpha-induced cell death of human umbilical vein endothelial cells (HUVECs) and Jurkat cells in a concentration of 100 microM when applied 2 h prior to TNF-alpha exposure. Molecular studies revealed that PAC activated NF-kappaB with a maximum effect after 30 min of treatment. Inhibition of NF-kappaB action by MG132 and NF-kappaB inhibitory peptide suppressed the cell-protective effect of PAC. Further, degradation of IkBalpha occurred in response to PAC treatment. The results provide evidence that activation of NF-kappaB plays an important role in mediating the cell-protecting effect of PAC on HUVECs and Jurkat cells. Further studies are required to test whether PAC, a component of radix salviae miltiorrhizae, could be useful in preventing in vivo cell death resulting from cardiovascular or cerebrovascular diseases.

[Is disease grounded in the mind, the spirit or communication? Pathology as a leading path in learning about disease]

What is the reason, why pathology could command a dominating position as a central teaching discipline in the last 150 years? Furthermore: can this position be maintained in the future? Pathology takes its definitive stand in the philosophic confrontation of "Mind" versus "Matter". It guards the dogma of Morgagni: every disease is reflected by its typical morphological substrate. As long as this dogma is guarded and defended by the discipline of pathology, we will stay at the helm of teaching in medicine. Recently information as a third reality (besides mind and matter) has come into existence. Information is defined here as genomic information specifically the differentially activated functional genomics. In extension to the old dogma of Morgagni we recognize now an extension to "functional" diseases where we do not (yet) find a pathological anatomical manifestation. In these cases "information" is defined as differences in physical states. They can be converted to information in the sense of meaning and purpose by communication. Pathology provides the bridge between functional genomics and morphological manifestations of diseases (phenomics). The future of pathology is based on the amalgamation of the old and reliable Morgagni-Virchow dogma with the new informational dogma. If pathology provides sense, meaning and significance to phenomics, morphology in relation to functional genomics it will retain and even enlarge its influence as the most important teaching discipline in medicine.

Incidence and tumour stages of breast cancer in the region of Aachen, Germany

We present epidemiological data of female breast cancer in the region of Aachen (Germany) including incidence and tumour stages for the period 1996-1997. Furthermore, we compare epidemiological data from Aachen with data from the directly neighbouring Dutch region South-Middle Limburg before and after the introduction of a national mammographic screening programme. The field study of breast cancer was undertaken at the Institute of Pathology and Comprehensive Cancer Center at the University of Aachen, supported by the Federal Ministry of Health (Germany), using data files from the Cancer Registry Aachen. The patient's consent to collect all data concerning her epidemiological and social situation as well as information on the outcome of disease was obtained in 83.4% of all cases. The remaining 16.6% of the cases without a patient's consent are based on histopathological reports. Only those patients are included who were documented as residing in the region of Aachen at the time of diagnosis. Tumour cases were counted according to International Agency for Research on Cancer rules and tumour stages are classified according to UICC guidelines. Incidence rates are calculated as crude value, adapted to the European and World Standard population (ESR, WSR), and the age specific incidence is presented in 5-year intervals. The cumulative risk is assessed for a certain life span by summarizing the age-specific incidences. The age-standardized breast cancer incidence rate in Aachen was 94 per 100 000 women in 1996 and 90 cases of invasive breast cancer per 100 000 women in 1997 according to the ESR. The cumulative risk of developing breast cancer in the life span ranging from 0 to 74 years is approximately 8%. The stage distribution of breast cancer reveals only 4% favourable carcinomata in situ, but 12% advanced T4 tumours. T1 and T2 tumour stages count for about 40% and T3 tumour stages about 4%. Incidence rates and the tumour stages of breast cancer in the region of Aachen during 1996 and 1997 are similar to the data obtained from the directly neighbouring Cancer Center of the region South-Middle Limburg, in the Netherlands, in 1989/1990 before the beginning of the national breast cancer screening programme. However, major differences are found in terms of the incidence and the tumour stages between Aachen 1996/1997 and South-Middle Limburg 1995/1996 after the introduction of the mammographic screening. The incidence of female breast cancer in Aachen, Germany, was high and in the range of the data from other cancer registries in Europe without national screening programmes. The tumour stages at diagnosis in Aachen were not very favourable, especially in elderly women. An increase of the cancer incidence and a shift of the tumour stages to more favourable ones were observed in the neighbouring Dutch region of South-Middle Limburg, comparing data from 1989/90 and 1995/96. This is probably as a result of the national mammographic screening programme. As data from Aachen were similar to Limburg's data from 1989/90 before the mammographic screening was introduced, it will be important to follow and compare the cancer incidence and the tumour stages in the future.

Benign solitary fibrous pleural tumour. Evidence of primitive features and complex genomic imbalances, including loss of 20q

AIMS

Cytogenetic data on solitary fibrous tumours (SFT) are very limited. We studied a benign pleural SFT for its ultrastructural and immunohistochemical details, and made cytogenetic analyses for comparison with other genetic and ultrastructural studies of SFT.

RESULTS

Immunohistochemistry showed strong positivities for CD34 and vimentin, but no reactions with anti-cytokeratins and epithelial membrane antigens. Electron microscopy revealed primitive desmosomes in our SFT. The results thus evinced fibroblast-like cells with intermediate epithelial-mesenchymal character. Comparative genomic hybridization of the tumour revealed losses of 1p33-->pter, 17pter q21, entire copies of chromosomes 19 and 22, and gains of 1p21-p22, 2q23-q32.3, 3pl2-q13.2, 4p14-q28, 6p12-q21, 9p21-->pter and 13q21-q31. Furthermore, there was loss of 20q, as was previously reported elsewhere in a case of benign and a case of malignant SFT.

CONCLUSIONS

The results furnish further evidence of the involvement of -20q in SFT. In addition, they show that SFT may have complex genomic imbalances and primitive features, despite having a benign appearance.

Von Willebrand's factor mediates the adherence of human tumoral cells to human endothelial cells and ticlopidine interferes with this effect

The aim of this study was to explore whether von Willebrand's factor (vWF) plays a role in the adhesion of human colon tumor cells to human endothelial cells in our coculture system. Cell colony density was evaluated basally (endothelial plus colon tumor cells) and following the addition of: purified vWF, vWF plus vWF-blocking antibodies, antibodies against various integrins and adhesion molecules (alpha2 b integrin, beta1 integrin, beta3 integrin, intercellular adhesion molecule-I, intercellular adhesion molecule-II, vitronectin receptor CD61 CD51, laminin alpha6/beta4 receptor), and various drugs inhibiting the hemostatic system (ticlopidine, heparin, acetyl salicylic acid [ASA], defibrotide, indobuphen, dipyridamole, sulfinpyrazone). Furthermore, vWF concentration was measured in the supernatant fluid of the coculture system basally and following the addition of the above-listed drugs. Cell colony density (as measured by light absorption) increased by 33% following the addition of vWF and returned to a value similar to the basal level with antibodies against vWF, while it did not change significantly following the addition of antibodies against the other integrins or adhesion molecules tested. The same parameter was reduced by 35% following the addition of ticlopidine, while it showed a smaller or no change with the other drugs tested. Similarly, vWF concentration in the cell coculture supernatant showed the greatest reduction (from 0.22 to 0.11 mg/mL) following the addition of ticlopidine. These data suggest that vWF mediates the adherence of human tumor cells to human endothelial cells and that ticlopidine interferes with this effect.

[Expanded, radical perineal prostatectomy]

One hundred and twenty-five consecutive patients with prostate cancer underwent an extended, radical perineal prostatectomy according to the technique described by VE Weldon. This technique was modified by an initial complete mobilization of the posterior aspect of the prostate and seminal vesicles from the rectum and pelvic wall, incision of the endopelvic fascia, and partial resection of the dorsal vein complex after suture ligature. The perioperative morbidity was low. An operative revision was necessary in four (3.2%) patients because of arterial bleeding from a drainage channel (n = 1), wound infection (n = 2), and rectocutaneous fistula (n = 1). The in-dwelling catheter was removed on day 4-8 in 104 (83%) patients. Positive surgical margins were diagnosed in 22 (17.6%) patients only. These patients had pT3 (n = 17) and pT4 (n = 5) tumors with a Gleason score > or = 7 (n = 17) mostly; extensive, multifocal capsular penetration (n = 18); seminal vesicle invasion (n = 11); and lymph node metastases (n = 4). The unifocal positive margins were localized at the apex (n = 3), dorsolateral (n = 6) aspect, and bladder neck (n = 4). In nine patients, multifocal positive surgical margins were noted. The risk for a positive surgical margin depends on the serum PSA level, Gleason score, and tumor volume. In case potency preservation is not considered, the extended, radical perineal prostatectomy with the above mentioned modifications should be considered to guarantee a low rate of surgical margins.

Effects of Nd:YAG-laser irradiation on monolayer cell cultures

BACKGROUND AND OBJECTIVE

The clinical applications of Nd:YAG lasers on oral soft tissues include a wide field of surgical and periodontal procedures. This in vitro study focuses on the histological effects of Nd:YAG-laser irradiation on a fibroblast monolayer cell culture especially with regard to thermal damage and cell necrosis. The results of this basic research study provide us with clear power settings for a safe soft tissue laser treatment.

STUDY DESIGN/MATERIALS AND METHODS

Two hundred forty multiwell cell cultures and 24 micro-slide Leighton tubes were laser treated. Laser irradiation was performed with a commercial free-running pulse Nd:YAG laser and a quartz fiber with a diameter of 200 microns on L-929 fibroblast cell cultures. The variable parameters were pulse energy (30-120 mJ), pulse rate (20-100 Hz), power output (1.5-3.0 W), and time of irradiation (10-60 s). The cultures were analyzed with help of vital staining, autoradiography, and cytomorphology examination.

RESULTS

Depending on the different settings the laser irradiation caused inhibitions of the DNA metabolism rate and the cell division rate, a degeneratively changed cytomorphology up to cell pyknosis. An increasing pulse energy, pulse rate, or an increased time of irradiation created an extended diameter of the pyknotic cell zone.

CONCLUSIONS

The laser beam creates an exactly bordered damage between cells. The cells had a very good inherent mobility, but the border between eliminated and unloaded cell zone was sharp, even after an incubation of 24 h. These stable results prove that the laser can be applied up to a micrometer distance. With the help of cell clusters it was proved that the laser beam is also able to eliminate exactly one monolayer. Cells which had been covered by another cell layer (in a cluster) were not eliminated.

MIB-1 immunohistometry of follicular adenoma and follicular carcinoma of the thyroid gland

OBJECTIVE

To analyze cellular proliferative activity, MIB-1 immunopositivity of normal tissue (n = 20), follicular adenoma (n = 30) and follicular carcinoma (n = 32) of the thyroid gland was analyzed by means of immunohistometry.

STUDY DESIGN

Immunohistochemical reactions were performed on 3-micron sections from routinely formalin fixed and paraffin embedded surgical specimens using an indirect peroxidase method. The rate of immunostained cells was determined using the CM-2 TV image analysis system (Hund, Wetzlar, Federal Republic of Germany). Forty viewing fields (1.94 mm2) were measured with 20:1 objective magnification. An average of 5,965 cells were assessed in each case.

RESULTS

Mean MIB-1 immunopositivity was higher in follicular carcinoma (average, 2.30%) and follicular adenoma (0.58%) than in normal thyroid tissue (0.14%). The distribution of single values differed significantly between groups (P < .001). To test the suitability of MIB-1 immunohistometry for the differential diagnosis of follicular adenoma and follicular carcinoma, different four-field tables with varying thresholds were calculated. Using a threshold of 0.9%, follicular carcinoma could be detected with a sensitivity of 75% (24/32) and a specificity of 83% (25/30). If a specificity of 90% is required (27/30), the sensitivity of the test decreases to 69% (22/32), based on a threshold of 1.1%.

CONCLUSION

As some overlap of single values has to be considered, MIB-1 immunohistometry, although presenting new insights into the proliferative potential of thyroid lesions, is of only limited value for the differential diagnosis of follicular lesions in routine surgical pathology.

Expression of heat shock proteins 72/73 in human peritoneal mesothelial cells in vivo and in vitro

Leukocyte accumulation during peritonitis leads to an injurious microenvironment which is involved in the host defense reaction but is also thought to cause peritoneal damage. We tested the hypothesis that mesothelial cells (MC) respond to the injurious microenvironment during peritonitis by an increased expression of heat shock proteins (HSP 72/73), a basic way by which cells are protected against injury. Comparison of resting MC and activated MC during peritonitis in vivo by means of immunohistochemistry revealed an increased expression of HSP 72/73. As assessed by Western immunoblotting, incubation of MC in vitro with tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) caused a time-dependent induction of HSP 72/73 expression, which was maximal 6 h after stimulation. We suggest that the increased HSP 72/73 expression of MC during peritonitis is in part induced by TNF-alpha and IL-1beta and may exert a cell-protective function, lessening MC damage during peritonitis.

Increased apoptosis of hepatocytes in vascular occlusion after orthotopic liver transplantation

Early vascular occlusion is liable to cause graft failure, and differential diagnosis between this condition and primary nonfunction (PNF) caused by preservation injury may be difficult. Apoptosis has been detected in immunomediated cytotoxicity and is known to be triggered by mild ischemia. In a retrospective analysis we investigated the role of apoptosis in vascular occlusion, PNF, and acute allograft rejection to improve the differential diagnosis of early graft failure. The liver graft histology of 75 patients (46 male, 29 female) a median 47 (1-64) years of age was screened semiquantitatively for the rate of apoptosis on the hematoxylin-eosin stain (HE) and by the in situ end nick labeling technique (TUNEL). This cohort included all patients who developed PNF (n = 9) or vascular occlusion (n = 11) after orthotopic liver transplantation (OLT) in the years 1992 to 1996. Within this period of time we performed 205 OLTs on 189 patients. We further included 22 patients with early acute rejection and 11 controls. The highest rates of apoptotic hepatocytes were seen in vascular occlusion (P < 0.001). Grafts with PNF were explanted 1-3 days after OLT and showed hepatocytes that were 100% necrotic. Cases of acute early rejection showed a significantly higher apoptotic cell count than did normal controls (P < 0.003), increasing in direct proportion to the severity of rejection. Screening biopsies for the rate of apoptosis can improve the efficacy and accuracy of differential diagnosis of early graft failure.

Interphase cytogenetics of multicentric renal cell tumours confirm associations of specific aberrations with defined cytomorphologies

To demonstrate associations of certain chromosomal aberrations with defined renal cell tumour (RCT) subtypes, we analysed 239 tumour nephrectomy cases for specimens with multicentric tumours. Chromosomal in situ hybridization was then performed on 15 cases with 34 foci (16 conventional renal cell carcinomas (RCCs), and 18 papillary RCTs (11 carcinomas and seven adenomas) for specific chromosomal aberrations, using alpha-satellite probes for chromosomes 3, 7 or 17. Particular preference was given to cases which had separate foci with different cytomorphologies. Furthermore, we compared aberrations in relation to tumour size, stage, grade and between different foci in a specimen. Thirty-four cases had multiple tumours. Forty-seven per cent of the multicentric tumours were conventional RCCs and 53% papillary RCTs (against 83% solitary conventional RCCs and 5% solitary papillary RCTs). Three conventional RCCs sized 8 mm (G3), 13 cm (pT2, G2) and 15 cm (pT3b, G3), respectively, revealed monosomy 3, and 13 were disomic. Seventeen papillary RCTs (11 carcinomas and six adenomas) displayed trisomy 17, irrespective of size or grade. Four papillary carcinomas and six papillary adenomas had trisomy 7, and the rest (seven papillary carcinomas and one papillary adenoma) revealed disomy 7. In conclusion, papillary RCTs were tendentially multicentric. Although specific for conventional RCCs heedless of size, monosomy 3 was only observed in high-grade and/or advanced tumours. Trisomy 17 was only detectable in papillary RCTs irrespective of tumour state, showing increased copies with tumour growth. Papillary RCTs also appeared to lose some copies of chromosome 7 with tumour progress, possibly reflecting malignancy.

Expression of heat shock protein 70 (HSP70) at the interface of polymer-implants in vivo

Synthetic polymer meshes are widely applied in the modern surgical approach for repairing abdominal wall defects. The implanted material is often observed leading to post-operative complications such as deficient abdominal wall mobility and adhesion formation with the abdominal cavity and/or abdominal organs. However, the functioning of the implant is primarily affected by the wound healing process guided by inflammatory events occurring at the tissue-material interface. This could presumably be influenced by the physicochemical properties of the polymer. With regard to it, the cellular and molecular processes involved in the successful restoration of the abdominal wall function are poorly understood. The present in vivo study, therefore, exemplary investigated in a rat model, the commercially available polymer-meshes Prolene (polypropylene, PP), Mersilene (polyester, PE) and Vicryl (polyglactin 910), as well as new mesh variants consisting either of PP (EB) or a combination of PP and polyglactin 910 (A plus or Vypro). The implanted material was evaluated by light and electron microscopy, immunohistochemistry as well as morphometry over an implantation period of 90 days. The data show that polymers induce heat shock protein (HSP)70, and its expression at the interface correlates inversely with the activity of the inflammatory reaction in vivo. Further, an ascent in HSP70 expression parallels the increasing implantation period and evolving foreign-body granulomas. Accordingly, a major role for HSP70 in modulating the local acceptance of polymers and as an additional marker for in vivo testing of polymers is suggestive.

Simultaneous appearance of an adenomyoma and pancreatic heterotopia of the stomach

Adenomyomas of the stomach are rare tumours characterised by duct/gland-like structures embedded within a smooth muscle stroma. Although the histogenesis of adenomyomas remains unclear, the histological appearance has justified the assumption that these are abortive forms of pancreatic heterotopia. We report an unusual case with simultaneous and independent appearance of both adenomyoma and pancreatic heterotopia of the stomach including immunohistochemical characterisation, supporting the concept of a common histiogenetic origin of both lesions.

Successful long-term implantation of electrically inactive epiretinal microelectrode arrays in rabbits

BACKGROUND

In the ongoing discussion concerning the realization of an epiretinal prosthesis for electric stimulation of retinal ganglion cells, long-term fixation of such a device is a crucial question. We evaluated surgical techniques for implantation and fixation of electrically inactive microelectrode arrays (MA) into the retinas of rabbits and secondary tissue reactions to the implant.

METHODS

Vitrectomy and laser coagulation of the prospective fixation area were performed in rabbits. Implantation of MAs was performed 3 weeks later in 10 animals. The MA was fixated using retinal tacks. The follow-up included ophthalmoscopy and electrophysiology. At the end of the follow-up, the enucleated eyes were processed for light microscopy using standard procedures and grinding techniques.

RESULTS

Nine of 10 rabbits were implanted without serious complications. Clinical and electrophysiologic data through 6 months of follow-up did not indicate any adverse effect of the surgery, the implant, or the tack itself. No change in retinal architecture underneath the implant was found by light microscopy. In these cases, the implant was stable at its original fixation area. In three cases, mild cataract formation was observed, and in one case, a total retinal detachment was found.

CONCLUSION

Tack fixation of electrode arrays for electric stimulation of the inner retinal surface seems to be a useful approach in long-term implantation of an epiretinal prosthesis.

Elevated soluble adhesion molecules in women with pre-eclampsia. Do cytokines like tumour necrosis factor-alpha and interleukin-1beta cause endothelial activation

OBJECTIVE

The purpose of the present study was to evaluate the clinical significance of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) for endothelial cell activation in pre-eclampsia. Therefore, we determined and compared the correlations between these cytokines and circulating adhesion molecules in the sera of pre-eclamptic pregnant women, normotensive pregnant women and nonpregnant women.

METHODS

The soluble adhesion molecules VCAM-1, ICAM-1, E-selectin, and P-selectin were determined in the serum of 38 pre-eclamptic pregnant women and 40 normotensive pregnant and nonpregnant controls using ELISA-techniques. We correlated these serum concentrations with the serum levels of TNF-alpha and IL-1beta, respectively, also determined by ELISA.

RESULTS

Elevated serum levels of VCAM-1 and E-selectin could be detected in pre-eclamptic patients, with and without HELLP-syndrome. In contrast, no increased serum concentration of ICAM-1, P-selectin, TNF-alpha and IL-1beta were found in these patients. While significant correlation between VCAM-1 and E-selectin could be determined (r=0.604; p<0.001) no unambiguous correlations, however, were found between TNF-alpha or between IL-1beta and the examined adhesion molecules or the selectins.

CONCLUSIONS

In contrast to in vitro investigations on cultured umbilical vein endothelium, our experimental results indicate that the cytokines TNF-alpha and IL-1beta can not explain endothelial cell activation, and that their measurement in serum is not useful for the detection of pre-eclampsia.

Preservation solutions for transplantation

Eurocollins has almost been abandoned because of the glucose disadvantage. UW is certainly the most used preservation solution for livers, kidneys, and pancreases with excellent clinical and experimental preservation data. UW can certainly be considered the current golden standard solution. However, the disadvantage of high viscosity, high price, uneasy handling of many 1-L bags, and the fact that the radical scavenger glutathion cannot be detected in the bags by chemical analysis (presumably due to diffusion) encourage competitors to produce new compounds with better cost to effect ratios. HTK has a firm place in cardiac preservation; by demonstration of equal safety and efficacy in preserving livers and kidneys, at least in the middle and lower range of cold ischemia time, HTK will be sued more frequently, particularly with the consideration of lower price and more easy handling aspects. The suggested high volume perfusion is not really necessary, calculation based on a total volume of 10 L for a multiorgan donor show significant cost reductions. Celsior is current only used for cardiac preservation. Beyond all aspects of conservation and preservation potencies of all these fluids, it must not be forgotten that cold ischemia itself is a risk factor for organ function. Therefore, cold ischemia time should be kept as short as possible. People are willing to accept 24 hours or more cold ischemia time in kidney transplantation because organ failure can be treated by dialysis. In other organs, where immediate organ function is essential, like in clinical heart transplantation, cold ischemia is hardly ever extended beyond 6 hours. Why are hearts and kidneys so different? Very likely, there is no difference, and the outstanding results in living unrelated kidney transplants is mostly due to short cold ischemia time.

Intraperitoneal transplantation of isologous mesothelial cells for prevention of adhesions

OBJECTIVE

To study the effect of transplantation of mesothelial cells on the formation of adhesions after peritoneal abrasion.

DESIGN

Animal study.

SETTING

Teaching hospital, Germany.

ANIMALS

30 isologous eight-week old Lewis rats to allow for harvesting of the greater omentum from a separate group.

INTERVENTIONS

The first group (n = 10) served as mesothelial cell donors. The other animals had laparotomy and induction of adhesions by standardised abrasion of the peritoneum. The trial group (n = 10) were given a suspension of 10(6) mesothelial cells/100 g body weight intraperitoneally and the control group (n = 10) an equal volume of culture medium. After 10 days the animals were killed.

MAIN OUTCOME MEASURES

Measurements of the areas of adhesions by computer aided morphometry.

RESULTS

The trial group developed a mean (SD) adhesion area of 122.7 (176.7) mm2, and the controls 310.5 (179.1) mm2. The corresponding medians (range) were 51.2 (0-547.1) and 274.3 (100.6-575.4). Transplantation of mesothelial cells resulted in a significant reduction in adhesion formation (Wilcoxon test, p<0.01).

CONCLUSION

Intraperitoneal transplantation of mesothelial cells is an effective way of reducing the formation of adhesions.

Inhaled nitric oxide in a patient with severe pulmonary embolism

We describe a 66-year-old woman with right-sided heart failure and cardiogenic shock resulting from severe pulmonary embolism. Her hemodynamic status improved dramatically with the use of inhaled nitric oxide. A proposed mechanism of action and a review of the literature are presented.

Inhalation of nitric oxide as a life-saving therapy in a patient after pulmonary embolectomy

We describe a 54-yr-old man with cardiogenic shock caused by acute right heart failure after pulmonary embolectomy. Inhalation of nitric oxide led to immediate improvement in respiratory and haemodynamic variables. Inhaled nitric oxide can be used to reduce acute right heart failure until conventional therapy can provide successful haemodynamic stability.

Diagnostic relevance of chromosomal in-situ hybridization in Merkel cell carcinoma: targeted interphase cytogenetic tumour analyses

AIMS

To resolve the conflicting diagnoses of five pathologists (which included well-differentiated neuroendocrine carcinoma, malignant carcinoid, undifferentiated small-cell carcinoma, primitive neuroectodermal tumour, metastases of small-cell lung carcinoma (SCLC) and Merkel cell carcinoma (MCC)), and tumour-free lungs after necropsy, we investigated an alarmingly metastasizing MCC in a 32-year-old Caucasian man using chromosomal in-situ hybridization (CISH). Differences in incidence and course in males and females also prompted targeted analyses for chromosomes X and Y. The lesion was also analysed for p53 gene mutations.

METHODS AND RESULTS

Paraffin sections of the thorax, buccal lymph nodes and scalp tumours were stained with haematoxylin and eosin. Immunohistochemistry was performed with antibodies against pancytokeratin, keratin 20, neuron-specific enolase (NSE), chromogranin, neurofilaments and vimentin, among others. Sections (5-6 microm) of the tumours were analysed with alpha-satellite probes for chromosomes 1, 6, 7, 11, 12, 17, 18, X and Y using CrSH; and exons 5-9 of the p53 gene were examined by polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP) methods. Although positive for pancytokeratin, keratin 20, chromogranin, NSE, synaptophysin and vimentin, the similarity in antigen profiles expressed by SCLC and MCC prevented a definitive tumour diagnosis. Chromosomal in-situ hybridization, however, revealed trisomies 1 and 11, two frequent aberrations in MCC, and trisomy 18. Moreover, 71% of the tumour cells had two to three copies of X, whereas 98% of the cell nuclei in the hair follicles and normal epidermis (purported Merkel cell origins) displayed one X chromosome. No mutations were detected in the five exons of the p53 gene examined.

CONCLUSIONS

Had CISH been performed earlier, treatment may have been tailored specifically to suit MCC, since MCC and SCLC have different therapeutic strategies. Finally, chromosome X may be of prognostic relevance in MCC, which apparently predominates in females and yet shows poorer prognosis in males, and hence be worthy of further investigation.

Absence of epidermal growth factor receptor expression in squamous cell carcinoma of the uterine cervix is an indicator of limited tumor disease

The expression of growth factors is considered as an important diagnostic and prognostic feature in tumor pathology. We investigated the value of the immunohistochemical EGF-receptor expression (EGF-R) in 30 squamous cell carcinomas of the uterine cervix, treated by radical hysterectomy and lymphadenectomy according to the Wertheim-Meigs-Okabayashi technique. Immunohistochemical reactions were performed on 4 microm sections from paraffin-embedded tissue, using an indirect peroxidase method. The staining results were evaluated semiquantitatively as negative (n=9; 30%) or as slightly, moderately or severely positive (n=21; 70%). The EGF-R-negative tumors were found in less advanced tumor stages. None had invaded into the parametrium (100%), eight were staged as T1 (89%), seven as N0 (78%), and seven showed no evidence for lymphangiosis carcinomatosa (78%). The respective values for the EGF-R-positive tumors ranged from 52% to 67%. However, only the difference in parametral invasion (EGF-R-negative: 0%, EGF-R-positive: 38%) was statistically significant (p=0.0306), probably due to the small number of cases. The EGF-R-expression was not correlated to histomorphological tumor grading. The results of this study indicate an inverse correlation between EGF-R expression and tumor spread. Assuming that this trend could be confirmed by a larger group of patients, immunostaining for EGF-R in a tumor biopsy could be useful to adapt surgical strategies and adjuvant therapy in the individual patient. Moreover, the EGF-R is an interesting target for immunotherapeutic approaches in squamous cell cervical carcinoma.

The role of soluble adhesion molecules in evaluating endothelial cell activation in preeclampsia

OBJECTIVE

Adhesion molecules, such as vascular cell adhesion molecule 1, are known to be increased in the serum of patients with preeclampsia, indicating that these molecules are possible markers of endothelial cell activation. We investigated the influence of serum from women with preeclampsia on the expression of adhesion molecules by cultured endothelial cells.

STUDY DESIGN

Human umbilical vein endothelial cells were cultured in Ham/Iscove modified Dulbecco's medium containing 20% pooled human serum, l -glutamine (200 mmol/L), penicillin, and streptomycin. We stimulated these cells for 24 hours with sera from patients with preeclampsia and then determined the levels of vascular cell adhesion molecule 1, intercellular cell adhesion molecule 1, E-selectin, and P-selectin in the supernatant and in the maternal serum by means of enzyme-linked immunosorbent assay. These results were compared with those of sera obtained from normotensive pregnant and nonpregnant women. In addition, the expressions of these adhesion molecules on the endothelial surface were determined by immunofluo-rescence microscopy.

RESULTS

Only for vascular cell adhesion molecule 1 and E-selectin were elevated plasma levels found in hypertensive patients, whereas intercellular cell adhesion molecule 1 and P-selectin showed similar plasma levels in all the patients. No differences in the levels of the adhesion molecules were found between the supernatants of endothelial cell cultures after stimulation with sera from patients with preeclampsia and those after stimulation with normotensive control sera. In contrast, with immunofluorescence microscopy we could detect higher amounts of vascular cell adhesion molecule 1, intercellular cell adhesion molecule 1, and E-selectin on the endothelial surface after stimulation with sera from women with preeclampsia.

CONCLUSION

Although vascular cell adhesion molecule 1 and E-selectin were elevated in maternal serum samples from women with preeclampsia and on the endothelial surface after stimulation with such sera, there were no detectable increases in the levels of both of these adhesion molecules in the supernatant of cultured endothelial cells. We therefore assume that sera from women with preeclampsia may cause endothelial cell activation. Because we could not detect elevated concentrations of any of the investigated adhesion molecules in the supernatant of endothelial cells, we believe that factors other than sera from women with preeclampsia seem to play a major role in the release of soluble forms of adhesion molecules from the endothelial membrane.

Uremic medium increases cytokine-induced PAI-1 secretion by cultured endothelial cells

The overall fibrinolytic activity is depressed in patients with chronic renal failure where a prothrombotic state is described, thereby enhancing the risk of vascular occlusive events. The mechanism responsible for fibrinolysis derangement has not yet been elucidated. To evaluate the effect of the uremic environment on the fibrinolytic activity of endothelial cells, we studied plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) production by human umbilical vein endothelial cells (HUVEC) in culture, exposed either to uremic or normal sera, before and after cytokine stimulation. Twenty uremics were studied: 11 were on conservative dietary treatment and nine were on maintenance hemodialysis. Eight healthy subjects served as controls. Before cytokine stimulation, no difference in the HUVEC supernatant concentration of t-PA and PAI-1 was found among the groups studied. After stimulation with interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha, the HUVEC supernatant levels of PAI-1 in the uremics were higher than in the controls, whereas the supernatant levels of t-PA did not differ. Our data provide evidence that uremic serum, in concert with IL-1 or TNF-alpha, can enhance PAI-1 secretion by endothelial cells, thereby depressing the fibrinolytic system. This impaired endothelial fibrinolytic response to hypercoagulation could favor vascular events, which are the major cause of morbidity and mortality in patients with chronic uremia.

Cytogenetic analysis of 11 renal oncocytomas: further evidence of structural rearrangements of 11q13 as a characteristic chromosomal anomaly

We carried out cytogenetic analysis on 11 renal oncotytomas by using G-banding and DAPI-banding techniques. Four of our tumors exhibited structural rearrangements affecting chromosome 11 at band q13. Together with another case previously described by us, our tumors constitute the largest series of renal oncocytomas displaying translocations involving 11q13. A review of the literature disclosed only 6 similar oncocytomas, 1 tumor with a t(9;11)(p23;q12), 2 tumors with a nearly identical t(9;11)(p23;q13), and 3 tumors with a t(5;11)(q35;q13). Therefore, our findings provide further cytogenetic evidence that genes located on 11q12-13 may be involved in the tumorigenesis of renal oncocytomas.

Modulation of pro- and antifibrinolytic properties of human peritoneal mesothelial cells by transforming growth factor beta1 (TGF-beta1), tumor necrosis factor alpha (TNF-alpha) and interleukin 1beta (IL-1beta)

A decreased fibrinolytic activity of serosal surfaces appears to be a major factor in the development of peritoneal fibrous adhesions. Serosal fibrinolysis is regulated by mesothelial release of tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor types 1 and 2 (PAI-1 and PAI-2). We investigated the influence of tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta1) and interleukin 1beta (IL-1beta) on pro- and antifibrinolytic properties of mesothelial cells (HOMC) using a cell/fibrin clot assay. TGF-beta1, TNF-alpha and IL-1beta induced a dose dependent 2.9, 2.3 and 1.9-fold increase of PAI-1 antigen, respectively, whereas t-PA concentrations decreased to one third of the control values. This modified PAI-1/t-PA secretion pattern leads to a significant delay of fibrinolysis. Analysis of m-RNA levels revealed increased PAI-1 m-RNA concentrations after 12 h and decreased m-RNA concentrations for t-PA after 6 h. Serosal hypofibrinolysis during peritonitis may be explained at least in part by cytokine effects which thus may favor adhesion formation.

Monocyte-biomaterial interaction inducing phenotypic dynamics of monocytes: a possible role of monocyte subsets in biocompatibility

For the in vitro study of cell-biomaterial surface interactions, the choice of cell type is crucial. In vivo data indicate that during the healing of the implant in the tissues, the pivotal cell types are the macrophages. These cells, upon interaction with any foreign material, might initiate a spectrum of responses, which could lead to acute and chronic inflammatory changes affecting the biocompatibility of the implant. Whether the mechanisms governing the type of evolving inflammatory reaction could be attributed to the macrophages functional differentiation mirrored by monocyte subsets during the polymer interaction, is poorly described. This in vitro study, therefore, attempted to investigate whether different biomaterials influence monocyte cellular activity, determined by the myeloperoxidase level and mitochondrial XTT cleavage, and phenotype dynamics characterized by the presence of CD14, RM 3/1 and 27E10 antigens. It is shown that different polymers exert differential potential to influence monocytes, both in their cellular activity and their phenotypic pattern. Thus, these findings demonstrating material-induced monocyte activation and monocyte phenotype modulation, are suggestive of the monocyte role as reporter cells in evaluating the biocompatibility of a synthetic medical device.

[Reduction of cataract by plasma etching of intraocular lenses. An animal experiment study]

BACKGROUND

We studied if a modification of the silicon intraocular lens (IOL) by plasma etching is able to promote a bonding of the IOL surface and the capsular bag which might inhibit proliferation and migration of lens epithelial cells.

METHODS

Silicon-disc lenses (90D, Adatomed), as disposable for regular cataract surgery, were used. Their haptic surface was etched via the use of a SO2 plasma, leaving the optic unmodified. The experiments were done on dwarf rabbits to allow for tight apposition of IOL and bag. Nine rabbits underwent extracapsular lensectomy using propofol anaesthesia and phaco/clear cornea surgical technique. Six eyes each received either no, a regular or a modified IOL. After 11 weeks the eyes were enucleated. Capsular bag and IOL were digitized using a flatbed scanner with transparency adapter. The data obtained were calibrated against a densitometric standard. The densities of the various specimen were analyzed quantitatively using self designed software.

RESULTS

In aphacic eyes no significant posterior capsule opacification (PCO) was detectable. In the same time-span the regular IOL had developed a dense, heterogenous PCO. The plasma-treated IOL showed, especially in the central areas, a significant reduction of PCO as compared to untreated IOL.

CONCLUSION

The reduction of PCO could not be explained by adhesion of the IOL surface and the capsular bag, which would impair migration of lens epithelial cells and thereby PCO. Likewise, lower PCO may be related to improved hydrophilic properties of the surface-modified IOL.

Screening of biomedical polymer biocompatibility in NMRI-mice peritoneal cavity: a comparison between ultra-high-molecular-weight polyethylene (UHMW-PE) and polyethyleneterephthalate (PET)

The peritoneal resident cell population is influenced by various inflammatory and immunogenic stimuli. The influence of intraperitoneal application of polyethyleneterephthalate (PET) (group A) and ultra-high-molecular-weight polyethylene (UHMW-PE) (group B) powders on peritoneal cell count and macrophage activity was investigated. Powders were tested to mimic wear particles from solid implant devices as these particles often cause chronic granulomatous inflammation. The results were compared with the inflammatory response following an abdominal midline incision (group C) and untreated animals (group D). On days 1, 7, 14 and 30 peritoneal cells were quantified and the number of active macrophages was assessed. Groups A and C mice showed a significant loss of macrophages in the peritoneal lavage at day 1 but this returned to normal values (group D) on day 7. In contrast, group B animals remained at low peritoneal cell counts but showed the highest number of active macrophages. Only in this latter group was adhesion formation and granulomatous clustering of polymer powder observed. Applying the parameters macrophage count and the number of active macrophages it can be concluded that PET elicits a weaker inflammatory reaction than UHMW-PE in mice peritoneal cavity. Thus this animal model may be used as a screening test for biomedical materials, especially their wear products.