[Cerclage using hollow screws for internal arthrodesis in cases of pronounced osteoporosis and osteopenia]. / Hohlschraubenunterstützte Rahmencerclage zur internen Arthrodese bei ausgeprägter Osteoporose und -penie.

Osteosynthesis of osteoporotic or osteopenic bone poses a considerable challenge for the surgeon, the type of osteosynthesis performed, and the osteosynthesis material employed. In osteoporotic and osteopenic bone, especially when circulation is decreased or sensitivity reduced, the principle of tension banding places great demands on the bone and surgeon since insufficient tightening of the wire results in inadequate immobilization while overtightening of the tension band can cause the wire to cut through the soft bone. This contribution describes a surgical technique, which prevents the wire from cutting through the bone. Cannulated screws are inserted vertically into the bone in the traction direction and the wire of the tension banding is passed through the cannulated screws. This ensures that the wire traction is distributed across the entire cross section of the bone. Thus, it is possible to completely tighten the tension band in osteopenic and osteoporotic bone. This technique is illustrated using the example of internal screw and tension band arthrodesis of the ankle joint, which achieved stable arthrodesis with weight bearing and recovered ambulation in a patient with pronounced diabetic foot syndrome and peripheral arterial occlusive disease.

[Secondary malignant melanoma of the gallbladder. A contribution to the differential diagnosis of pigmented lesions of the gallbladder]. / Sekundäres malignes Melanom der Gallenblase. Ein Beitrag zur Differenzialdiagnose pigmentierter Läsionen der Gallenblase.

The history of gallbladder involvement by a malignant melanoma in a 65-year-old woman is reported. The gallbladder, clinically resected for cholecystitis, harboured a polypoid dark pigmented tumour. The tumour was identified as a malignant melanoma immunohistochemically by positive reactions for gp100 (HMB45), melan A, and MiTF. Clinically, the patient was treated for cutaneous malignant melanoma by local excision 10 years earlier. The literature of pigmented lesions of the gallbladder is reviewed. In conclusion, the most important differential diagnosis of pigmented lesions of the gallbladder is the secondary gallbladder melanoma.

[Measurement of uranium isotope ratio in solid sample by laser ablation and double-beam diode laser atomic absorption].

The 235U/238U isotope ratio was determined by diode laser atomic absorption spectrometry in a plasma induced by a Nd:YAG laser. Two diode lasers, which probed almost the same plasma volume, were used as light sources. 235U and 238U absorption signals were simultaneously measured by tuning the diode lasers to the absorption lines 682.6736 nm and 682.0768 nm, respectively. The optimal focus position for the Nd:YAG laser was found to be 0.4 cm below the sample surface. The precision and accuracy of 235U/238U isotope ratio determination were obtained to be 5% and 2%, respectively. The detection limit of the 235U isotope, evaluated on the basis of 3sigma criteria, was estimated to be 18 microg x g(-1). All these results show an improvement compared with the method in which only one diode laser was used as a light source.

[Case management and functional outcome in persons aged 65 years and over with hip fracture]. / Case-Management und funktionelle Ergebnisse nach proximaler Femurfraktur im höheren Lebensalter.

The goal of the investigation was to study case management and functional outcome in older patients with hip fracture. A prospective observational survey was performed, including all patients aged 65 years and over presenting with hip fracture in Heidelberg, from 1 July 1999 to 30 June 2000. All patients were reassessed by telephone calls 6 months post-fracture. A total of 331 patients were included (mean age 81.5 years, 81% female,23.8% nursing home residents). Hip fracture incidence per 1,000 was 7.8/year, and nursing home residents had a six times higher incidence rate than those living at home. Prior to the fracture, half of the patients were dependent in ambulation and a third needed support in basic activities. With substantial comorbidity (42% cognitive impairment), complications were common. Geriatric care was needed for 82% of the survivors. In-hospital treatment costs were about 10,000 Euro per fracture. Mortality at 6 months was 19.9%. The majority of survivors showed loss of competence and mobility. Functional outcome in older patients with hip fracture is disappointing. As the majority of the patients are frail, clinical treatment is complicated by "geriatric" problems. Thus, improved interdisciplinary care, with close cooperation between geriatricians and surgeons might result in a better functional outcome.

The cysteine residue of the SoxY protein as the active site of protein-bound sulfur oxidation of Paracoccus pantotrophus GB17.

Four proteins of Paracoccus pantotrophus are required for hydrogen sulfide-, sulfur-, thiosulfate- and sulfite-dependent horse heart cytochrome c reduction. The lack of free intermediates suggested a protein-bound sulfur oxidation mechanism. The SoxY protein has a novel motif containing a cysteine residue. Electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry of the SoxYZ protein revealed one mass for SoxZ and different masses for SoxY, indicating native SoxY (10977 Da) and SoxY with additional masses of +32, +80, +112 and +144 Da, suggesting addition of sulfur, sulfite, thiosulfate and thioperoxomonosulfate. Reduction of SoxY removed the additional masses, indicating a thioether or thioester bond. N-Ethylmaleimide inhibited thiosulfate-oxidation and the kinetics suggested a turn-over-dependent mode of action. These data were evidence that the sulfur atom to be oxidized was covalently linked to the thiol moiety of the cysteine residue of SoxY and the active site of sulfur oxidation.

Dacron vs. polytetrafluoroethylene grafts for femoropopliteal bypass: a prospective randomised multicentre trial.

OBJECTIVES: To compare the patency of PTFE (Polytetrafluoroethylene) and unsealed knitted Dacron femoro-popliteal bypasses. DESIGN: Multi-centre prospective randomised trial. MATERIALS AND METHODS: Of 203 patients randomised, 194 were included in the final analysis (103 Dacron grafts and 91 PTFE grafts). The median follow-up was 36 months (range: 6-72 months); the distal anastomosis was above-knee in 141 and below-knee in 53 cases. Univariate comparisons of patency were made by the Kaplan-Meier method, multivariate calculations on the effects of covariables by a Cox regression analysis. RESULTS: There was no difference regarding primary and secondary patency or limb salvage between Dacron and PTFE. The primary 3-year patency for Dacron grafts was 64% (95% confidence interval [C.I.] 55-74%) and for PTFE grafts 61% (C.I. 49-72%). The corresponding 3-year secondary patency was 81% (C.I. 73-89%) and 75% (C.I. 65-86%) respectively, the limb salvage rate 90% (C.I. 84-96%) and 91% (C.I. 84-97%). Upon multivariate analysis below-knee anastomosis was the principal independent predictor of primary graft failure (risk ratio 1.7 [C.I. 1.05-2.8]), impaired secondary patency was associated with infragenicular bypass (risk ratio 3.3 [C.I. 1.8-6.3]) and distal gangrene (risk ratio [C.I. 1.01-3.8]p=0.048), major amputation was independently predicted by below-knee bypass, tissue necrosis, and poor run-off index. CONCLUSIONS: PTFE and Dacron are equally suitable for femoro-popliteal bypass.

Novel genes of the sox gene cluster, mutagenesis of the flavoprotein SoxF, and evidence for a general sulfur-oxidizing system in Paracoccus pantotrophus GB17.

The novel genes soxFGH were identified, completing the sox gene cluster of Paracoccus pantotrophus coding for enzymes involved in lithotrophic sulfur oxidation. The periplasmic SoxF, SoxG, and SoxH proteins were induced by thiosulfate and purified to homogeneity from the soluble fraction. soxF coded for a protein of 420 amino acids with a signal peptide containing a twin-arginine motif. SoxF was 37% identical to the flavoprotein FccB of flavocytochrome c sulfide dehydrogenase of Allochromatium vinosum. The mature SoxF (42,832 Da) contained 0.74 mol of flavin adenine dinucleotide per mol. soxG coded for a novel protein of 303 amino acids with a signal peptide containing a twin-arginine motif. The mature SoxG (29,657 Da) contained two zinc binding motifs and 0.90 atom of zinc per subunit of the homodimer. soxH coded for a periplasmic protein of 317 amino acids with a double-arginine signal peptide. The mature SoxH (32,317 Da) contained two metal binding motifs and 0.29 atom of zinc and 0.20 atom of copper per subunit of the homodimer. SoxXA, SoxYZ, SoxB, and SoxCD (C. G. Friedrich, A. Quentmeier, F. Bardischewsky, D. Rother, R. Kraft, S. Kostka, and H. Prinz, J. Bacteriol. 182:4476-4487, 2000) reconstitute a system able to perform thiosulfate-, sulfite-, sulfur-, and hydrogen sulfide-dependent cytochrome c reduction, and this system is the first described for oxidizing different inorganic sulfur compounds. SoxF slightly inhibited the rate of hydrogen sulfide oxidation but not the rate of sulfite or thiosulfate oxidation. From use of a homogenote mutant with an in-frame deletion in soxF and complementation analysis, it was evident that the soxFGH gene products were not required for lithotrophic growth with thiosulfate.

Cystic lymphangioma of the small-bowel mesentery: case report and a review of the literature.

Cystic lymphangioma of the small-bowel mesentery is a rare manifestation of an intraabdominal tumor in elderly patients. We present a case of a small-bowel mesentery lymphangioma, causing fever and chills and present clinical and pathologic features. Furthermore, etiology and differential diagnosis of this tumor are discussed.

Novel genes coding for lithotrophic sulfur oxidation of Paracoccus pantotrophus GB17.

The gene region coding for lithotrophic sulfur oxidation of Paracoccus pantotrophus GB17 is located on a 13-kb insert of plasmid pEG12. Upstream of the previously described six open reading frames (ORFs) soxABCDEF with a partial sequence of soxA and soxF (C. Wodara, F. Bardischewsky, and C. G. Friedrich, J. Bacteriol. 179:5014-5023, 1997), 4,350 bp were sequenced. The sequence completed soxA, and uncovered six new ORFs upstream of soxA, designated ORF1, ORF2, and ORF3, and soxXYZ. ORF1 could encode a 275-amino-acid polypeptide of 29,332 Da with a 61 to 63% similarity to LysR transcriptional regulators. ORF2 could encode a 245-amino-acid polypeptide of 26,022 Da with the potential to form six transmembrane helices and with a 48 to 51% similarity to proteins involved in redox transport in cytochrome c biogenesis. ORF3 could encode a periplasmic polypeptide of 186 amino acids of 20,638 Da with a similarity to thioredoxin-like proteins and with a putative signal peptide of 21 amino acids. Purified SoxXA, SoxYZ, and SoxB are essential for thiosulfate or sulfite-dependent cytochrome c reduction in vitro. N-terminal and internal amino acid sequences identified SoxX, SoxY, SoxZ, and SoxA to be coded by the respective genes. The molecular masses of the mature proteins determined by electrospray ionization spectroscopy (SoxX, 14,834 Da; SoxY, 11,094 Da; SoxZ, 11,717 Da; and SoxA, 30,452 Da) were identical or close to those deduced from the nucleotide sequence with differences for the covalent heme moieties. SoxXA represents a novel type of periplasmic c-type cytochromes, with SoxX as a monoheme and SoxA as a hybrid diheme cytochrome c. SoxYZ is an as-yet-unprecedented soluble protein. SoxY has a putative signal peptide with a twin arginine motif and possibly cotransports SoxZ to the periplasm. SoxYZ neither contains a metal nor a complex redox center, as proposed for proteins likely to be transported via the Tat system.

Characterization of a new type of sulfite dehydrogenase from Paracoccus pantotrophus GB17.

The periplasmic sulfite dehydrogenase of Paracoccus pantotrophus GB17 was purified to homogeneity by a four-step procedure from cells grown lithoautotrophically with thiosulfate. The molecular mass of native sulfite dehydrogenase was 190 kDa as determined by native gradient PAGE. SDS-PAGE showed sulfite dehydrogenase to comprise two subunits with molecular masses of 47 kDa and 50 kDa, suggesting an alpha2beta2 structure. The N-terminal amino acid sequence and immunochemical analysis using SoxC-specific antibodies identified the 47-kDa protein as the soxC gene product. SoxD-specific antibodies identified the 50-kDa protein as SoxD. Based on the molecular masses deduced from the nucleotide sequence for mature SoxC (43,442 Da) and SoxD (37,637 Da) sulfite dehydrogenase contained 1.30 mol molybdenum/mol alpha2beta2 sulfite dehydrogenase. The iron content was 3.17 mol/mol alpha2beta2 sulfite dehydrogenase, and 3.53 mol heme/mol alpha2beta2 sulfite dehydrogenase was determined by pyridine hemochrome analysis. These data are consistent with the two heme-binding domains (CxxCH), characteristic for c-type cytochromes, deduced from the soxD nucleotide sequence. Electrospray ionization revealed two masses for SoxC of 43,503 and 43,897 Da. The difference in molecular mass was attributed to the molybdenum cofactor of SoxC. For SoxD a mass of 38,815 Da was determined; this accounted for the polypeptide and two covalently bound hemes. Reconstitution of the catalytic activity of sulfite dehydrogenase required additional fractions; these eluted from Q Sepharose at 0.05, 0.25, and 0.30 M NaCl. The K(m) of sulfite dehydrogenase for sulfite was 7.0 microM and for cytochrome c 19 microM. Sulfite dehydrogenase activity was inhibited by sulfate and phosphate. The structural and catalytic properties make sulfite dehydrogenase from P. denitrificans GB17 distinct from sulfite oxidases of other prokaryotic or eukaryotic sources.

The classic nail in the therapy of trochanteric fractures.A prospective, controlled study.

In a prospective controlled study we analysed the classic nail, a new intramedullary implant for the fixation of peritrochanteric fractures. By means of lateral bending of 4 degrees, unreamed implantation is generally possible. Our collective of 85 patients was characterized by elderly mean age (82.3 years), a predominance of female patients (4.3 : 1), a minor trauma aetiology without relevant additional injuries, and a high rate of concomitant disease (92%). Only 31A-type femur fractures were treated, with a low specific complication rate of 13%, whereby operative revision was necessary in only two patients (3%). A good anatomic reconstruction and full weight-bearing with the osteosynthesis was achieved in the majority of patients. No secondary shaft fractures and only one case of cutting out was observed. The mortality (30 days: 18%, 6 months: 25%) as well as the high rate of unspecific complications (20%) were caused by the patients' multiple morbidity. Deficits in the Merle d'Aubigne score at follow-up after 6 months can be interpreted within the same context. Nevertheless, 85% could return to their former social environment and only 15% became dependent on a nursing institution in connection with the fracture treatment.

[The Richard classic nail (intramedullary hip screw, IMHS) as unreamed intramedullary nail in osteosynthesis treatment of pertrochanteric fractures]. / Der Classic Nagel nach Richards (Intramedullary Hip Screw, IMHS) als unaufgebohrter Marknagel bei der osteosynthetischen Versorgung pertrochanterer Frakturen.

The treatment of 85 patients with pertrochanteric femoral fractures (average age 82.3 years) with the Richards classic nail allowed full weight-bearing in 94.1% and unreamed implantation in 91.8%. In the follow-up period (11.2 months post-operatively) few complications (1.2% infections, 1.2% cutting out) could be documented. The Sanders and Regazzoni score revealed that 66% of the patients reached their preoperative status again. Statistical analysis showed a negative influence of patient age and fracture type on the postoperative walking ability.

Purification and characterization of the hydrogenase from Thiobacillus ferrooxidans.

Hydrogenase of Thiobacillus ferrooxidans ATCC 19859 was purified from cells grown lithoautotrophically with 80% hydrogen, 8.6% carbon dioxide, and 11.4% air. Hydrogenase was located in the 140,000 x g supernatant in cell-free extracts. The enzyme was purified 7.3-fold after chromatography on Procion Red and Q-Sepharose with a yield of 19%, resulting in a 85% pure preparation with a specific activity of 6.0 U (mg protein)-1. With native PAGE, a mol. mass of 100 and 200 kDa was determined. With SDS-PAGE, two subunits of 64 (HoxG) and of 34 kDa (HoxK) were observed. Hydrogenase reacted with methylene blue and other artificial electron acceptors, but not with NAD. The optimum of enzyme activity was at pH 9 and at 49 degrees C. Hydrogenase contained 0.72 mol nickel and 6.02 mol iron per mol enzyme. The relationship of the T. ferrooxidans hydrogenase to other proteins was examined. A 9.5-kb EcoRI fragment of T. ferrooxidans ATCC 19859 hybridized with a 2.2-kb XhoI fragment from Alcaligenes eutrophus encoding the membrane-bound hydrogenase. Antibodies against this enzyme did not react with the T. ferrooxidans hydrogenase in Western blot analysis. The N-terminal amino acid sequence (40 amino acids) of HoxK was 46% identical to that of the hydrogen sensor HupU of Bradyrhizobium japonicum and 39% identical to that of the HupS subunit of the Desulfovibrio baculatus hydrogenase. The N-terminal sequence of 20 amino acids of HoxG of T. ferrooxidans was 83.3% identical to that of the 60-kDa subunit. HupL, of the hydrogenase of Anabaena sp. Sequences of ten internal peptides of HoxG were 50-100% identical to the respective sequences of HupL of the Anabaena sp. hydrogenase.

Comparative investigation on copper oxides by depth profiling using XPS, RBS and GDOES.

Depth profiling has been performed by using X-ray photoelectron spectrometry (XPS) in combination with Ar-ion sputtering, Rutherford backscattering spectrometry (RBS) and glow discharge optical emission spectrometry (GDOES). The data obtained by XPS have been subjected to factor analysis in order to determine the compositional layering of the copper oxides. This leads to two or three relevant components within the oxide layers consisting of Cu(2)O or CuO dependent on the sample preparation. GDOES measurements show sputtering profiles which are seriously influenced by a varying sputter rate. To ensure the results obtained so far, RBS measurements of the oxide layers have been carried out in order to discover artefacts of the other methods used and to demonstrate the excellent suitability of RBS for quantitative analysis of these layers. Chemical analysis consisting of (1) carrier-gas fusion analysis (CGFA) and (2) selective dissolution of Cu(2)O/CuO allows the determination of the total amount of oxygen and copper, respectively, and can serve as a cornerstone of quantitative analysis.

Differential expression of beta 1 integrins in nonneoplastic smooth and striated muscle cells and in tumors derived from these cells.

Integrins are a superfamily of transmembrane alpha beta heterodimers that play an important role in cell-matrix and cell-cell interactions by acting as receptors for extracellular matrix proteins and for cell adhesion molecules. Using monoclonal antibodies against beta 1, alpha 1 to alpha 6, and alpha v subunits, the in situ distribution pattern of beta 1 integrins was examined immunohistochemically in nonneoplastic smooth and striated muscle cells and in their tumors. Nonneoplastic smooth muscle cells were beta 1+, alpha 1+, alpha 3+, alpha v+ and, in diverse localizations, also alpha 5+ or even alpha 6+. The expression of the beta 1 chain was conserved in all leiomyomas and leiomyosarcomas. The distribution pattern of the alpha subunits by contrast underwent several changes during malignant transformation of smooth muscle cells. These alterations consisted in a neoexpression of alpha 2, alpha 4, and alpha 6 as well as in an abnormal abrogation of alpha 1 and alpha 3 in some leiomyosarcomas. Except for the absence of alpha 5 in the majority of epithelioid leiomyosarcomas, expression of the alpha 5 and alpha v subunits was mainly conserved. In addition, tumors with epithelioid differentiation differed from typical cases by the absence of alpha 1 and the simultaneous presence of alpha 4. Adult striated muscle cells were beta 1+ but alpha 1- to alpha 6- and alpha v-, whereas fetal striated muscle cells were not only beta 1+ but also alpha 3+/-, alpha 4+/-, alpha 5+ and alpha 6+. In all rhabdomyosarcomas the expression of beta 1 was retained. Furthermore, the majority of cases showed the expression of one or more alpha subunits most of which, ie, alpha 4, alpha 5, and alpha 6, were also found in fetal striated muscle cells. In conclusion, beta 1 integrins exhibited a differential expression pattern along the two lines of myogenic differentiation. This integrin profile underwent characteristic changes during malignant transformation. Nevertheless, the compiled distribution patterns of the alpha 1, alpha 3, and alpha v subunits allowed in most instances the discrimination between tumors of smooth (alpha 1+/alpha 3+/alpha v+) and striated muscle (alpha 1-/alpha 3-/alpha v-) differentiation.

Evaluation of the secretory component as a prognostic variable in colorectal carcinoma.

Expression of the secretory component (SC) of IgA was investigated in normal colonic mucosa, in adenomas and in 188 colon carcinomas. Of the carcinoma patients, 149 underwent potentially curative surgical treatment. In particular, it was of interest to determine whether pathohistological or clinical parameters showed any association with the mode of SC expression in carcinomas. Irrespective of anatomical site, normal colon mucosa was generally SC-positive. Normal epithelium, however, displayed microheterogeneity in SC content, which was related to columnar and goblet-cell type and microtopographical site, implying a subtle regulatory mechanism. In contrast to adenomas, which were evenly SC-positive and showed focally weak SC expression in only 2 out of 20 cases, carcinomas were rather heterogeneous in their SC-expression pattern. In all, 48 carcinomas were entirely positive, 48 were completely negative and the remaining 92 showed various patterns of heterogeneous SC expression. The mode of SC expression was correlated with tumor staging, i.e., complete absence of SC was more often found in Dukes' C and D groups. In addition, the presence of SC in carcinomas was statistically correlated with the mucinous type. The mode of SC expression was not correlated with tumor grading and tumor location. The rate of disease-free survival and the risk of tumor-related death revealed a significant correlation with the mode of SC expression when patients who had received potentially curative or non-curative treatment were included in the log-rank test. Absence or low levels of SC expression were more frequent in the group that suffered a tumor relapse than in the recurrence-free cohort. Tumor-related death was more frequent when primaries were characterized by absence or low levels of SC expression. We conclude that absence or low levels of SC expression are an unfavorable prognostic variable in colorectal carcinoma.

Expression of APO-1 (CD95), a member of the NGF/TNF receptor superfamily, in normal and neoplastic colon epithelium.

APO-1 is a 48-kDa cell-membrane protein identical to the Fas antigen now designated CD95. It is a member of the NGF/TNF receptor superfamily. Anti-APO-1 monoclonal antibody induces apoptosis in a variety of cell types expressing this antigen. We immunohistochemically investigated APO-1 expression in normal colon mucosa, 20 adenomas, 258 colon carcinomas and 10 liver metastases and carried out in vitro studies using a panel of colon-carcinoma cell lines. Immunohistochemically, APO-1 was regularly expressed at the basolateral membrane of normal colon epithelia. In a minor fraction of colon adenomas and in 39.1% of colon carcinomas APO-1 expression was diminished and in 48.1% of carcinomas, predominantly of the non-mucinous type, APO-1 expression was completely abrogated. The normal level of APO-1 in carcinomas was correlated with the mucinous type. Reduced/lost APO-1 expression was more frequent in rectal carcinomas. Complete loss of APO-1 was more frequent in tumors that had already metastasized. APO-1 expression in liver metastases essentially corresponded to that of the primary tumors. Comparative analysis with data from previous studies revealed that the mode of APO-1 expression is correlated with that of HLA-A,B,C./beta 2m, HLA-DR, HLA-D-associated invariant chain and of the secretory component. Surface expression of APO-1 was heterogeneous in colon-carcinoma cell lines; SW480 expressed considerable amounts of APO-1 on all cells, while HT-29 constitutively did less so and only in a minority of cells. Surface density of APO-1 and the fraction of positive cells in HT-29 was enhanced by interferon-gamma (IFN-gamma) and, additively, by tumor necrosis factor-alpha (TNF-alpha), whereas in SW480 APO-1 expression was not modulated by these cytokines. We conclude that neoplastic transformation of colon epithelium often leads to a loss of the physiologic, high level of surface APO-1 by giving rise either to a stable lack of APO-1 or to an IFN-gamma/TNF-alpha-sensitive phenotype of inducible APO-1 expression.

Differential expression of beta 1, beta 3, and beta 4 integrin subunits in nonneoplastic neural cells of the peripheral and autonomic nervous system and in tumors derived from these cells.

BACKGROUND: Extracellular matrix proteins and their receptors take part in physiologic neural development and organization and also in abnormal neoplastic growth and spread. There is increasing evidence for the implication of integrins in these processes. EXPERIMENTAL DESIGN: Human tissues containing nonneoplastic neural cells of the peripheral and autonomic nervous system and a comprehensive series of neural tumors were examined for the in situ expression of beta 1, beta 3, and beta 4 integrins. Serial frozen sections of each tissue sample were immunostained using an indirect streptavidin/biotin-peroxidase method and monoclonal antibodies against beta 1, alpha 1 to alpha 6, beta 3, alpha v, and beta 4 subunits. RESULTS: Both small- and large-diameter nerve fibers of normal peripheral nerve trunks were consistently beta 1+, alpha 6+, and beta 4+ in the absence of alpha 3, alpha 4, alpha 5, and beta 3. Small-diameter nerve fibers further expressed alpha 1, alpha 2, and alpha v. Meissner's corpuscles and inner cores of Pacinian corpuscles shared the integrin repertoire of small-diameter nerve fibers with additional expression of alpha 3; outer cores of Pacinian corpuscles were beta 1+, alpha 3+, alpha 6+, and beta 4+. Regenerating nerve fibers paralleled the integrin profile of normal peripheral nerves. By contrast, malignant schwannomas showed considerable changes in integrin expression. These alterations consisted mainly in a neoexpression of alpha 3, alpha 4, and alpha 5 and in an abnormal loss of alpha 6 and beta 4. Expression of alpha 1, alpha 2, and alpha v was variable; absence of beta 3 was generally conserved. In ganglion cells, integrin expression was restricted to beta 1 and alpha 3 subunits, and chromaffine cells of the adrenal medulla even lacked any detectable beta 1, beta 3, and beta 4 integrin subunits. (Ganglio)-neuroblastomas, however, were beta 1+, alpha 1+, and alpha 3+, whereas primitive peripheral neuroectodermal tumors were beta 1+ and alpha 5+. CONCLUSIONS: Nonneoplastic human neural cells exhibit a complex and, at the same time, differential pattern of beta 1, beta 3, and beta 4 integrin subunit expression. Malignant transformation leads to considerable changes in this integrin profile. The observation of neoplasia-associated abnormalities underlines the important role of integrins in the orderly development and maintenance of human neural tissue. Some aspects of the emerging integrin subunit patterns are useful for the differential diagnosis of neural soft-tissue tumors.