Current level of technology use, health and eHealth literacy in older Canadians with a recent fracture-a survey in orthopedic clinics

Among older adults who have recently sustained a fracture, there is substantial adoption of mobile technology. Furthermore, health and eHealth literacy level reported by participants supports the development of interactive eHealth interventions toward fostering better patient engagement in skeletal health management.

INTRODUCTION

Electronic health resources are increasingly used in the self-management of medical conditions. We aimed to identify the current level of technology adoption, health, and eHealth literacy among older adults with a recent fracture, to determine if the use of electronic interventions would be feasible and acceptable in this population.

METHODS

Adults ≥ 50 years with recent fractures were invited to complete a self-administered survey composed of 21 questions, including an 8-item perceived eHealth literacy scale.

RESULTS

A total of 401 participants completed the survey (women, 64%; ≥ 65 years, 59%; university education, 32%). Most participants reported no difficulty in reading printed health material (67%) and felt confident in filling out medical forms (65%). Younger age and higher levels of education were associated with higher health literacy. Most respondents (81%) owned at least one mobile device (smartphone, 49%; tablet, 45%). eHEALS scores were similar among men (29, IQR 24-32) and women (29, IQR 25-33), and between younger age group categories (50-64 years, 30; IQR 26-33; and 65-74 years, 29; IQR 25-32), but lower in the oldest age group (≥ 75 years, 24; IQR 21-29; p < 0.05). Compared with the youngest group, those ≥ 75 years had higher odds of an eHEALS < 26 (odds ratio, 4.2; 95% confidence interval 2.0-8.9) after adjusting for sex and education level.

CONCLUSION

There is significant adoption of mobile technology among older adults. Health and eHealth literacy reported by this study population supports the development of interactive eHealth interventions toward fostering better patient engagement in skeletal health management.

X-ray Absorption and Emission Spectroscopic Studies of [L2Fe2S2](n) Model Complexes: Implications for the Experimental Evaluation of Redox States in Iron-Sulfur Clusters

Herein, a systematic study of [L2Fe2S2](n) model complexes (where L = bis(benzimidazolato) and n = 2-, 3-, 4-) has been carried out using iron and sulfur K-edge X-ray absorption (XAS) and iron Kβ and valence-to-core X-ray emission spectroscopies (XES). These data are used as a test set to evaluate the relative strengths and weaknesses of X-ray core level spectroscopies in assessing redox changes in iron-sulfur clusters. The results are correlated to density functional theory (DFT) calculations of the spectra in order to further support the quantitative information that can be extracted from the experimental data. It is demonstrated that due to canceling effects of covalency and spin state, the information that can be extracted from Fe Kβ XES mainlines is limited. However, a careful analysis of the Fe K-edge XAS data shows that localized valence vs delocalized valence species may be differentiated on the basis of the pre-edge and K-edge energies. These findings are then applied to existing literature Fe K-edge XAS data on the iron protein, P-cluster, and FeMoco sites of nitrogenase. The ability to assess the extent of delocalization in the iron protein vs the P-cluster is highlighted. In addition, possible charge states for FeMoco on the basis of Fe K-edge XAS data are discussed. This study provides an important reference for future X-ray spectroscopic studies of iron-sulfur clusters.

Fast proton-coupled electron transfer observed for a high-fidelity structural and functional [2Fe-2S] Rieske model

Rieske cofactors have a [2Fe–2S] cluster with unique {His₂Cys₂} ligation and distinct Fe subsites. The histidine ligands are functionally relevant, since they allow for coupling of electron and proton transfer (PCET) during quinol oxidation in respiratory and photosynthetic ET chains. Here we present the highest fidelity synthetic analogue for the Rieske [2Fe–2S] cluster reported so far. This synthetic analogue 5^x– emulates the heteroleptic {His₂Cys₂} ligation of the [2Fe–2S] core, and it also serves as a functional model that undergoes fast concerted proton and electron transfer (CPET) upon reaction of the mixed-valent (ferrous/ferric) protonated 5H^2– with TEMPO. The thermodynamics of the PCET square scheme for 5^x– have been determined, and three species (diferric 5^2–, protonated diferric 5H^–, and mixed-valent 5^3–) have been characterized by X-ray diffraction. pK_a values for 5H^– and 5H^2– differ by about 4 units, and the reduction potential of 5H^– is shifted anodically by about +230 mV compared to that of 5^2–. While the N–H bond dissociation free energy of 5H^2– (60.2 ± 0.5 kcal mol^–1) and the free energy, ΔG°_CPET, of its reaction with TEMPO (−6.3 kcal mol^–1) are similar to values recently reported for a homoleptic {N₂/N₂}-coordinated [2Fe–2S] cluster, CPET is significantly faster for 5H^2– with biomimetic {N₂/S₂} ligation (k = (9.5 ± 1.2) × 10⁴ M^–1 s^–1, ΔH^‡ = 8.7 ± 1.0 kJ mol^–1, ΔS^‡ = −120 ± 40 J mol^–1 K^–1, and ΔG^‡ = 43.8 ± 0.3 kJ mol^–1 at 293 K). These parameters, and the comparison with homoleptic analogues, provide important information and new perspectives for the mechanistic understanding of the biological Rieske cofactor.

Characteristics of CD4+CD25+ regulatory T cells in the peripheral circulation of patients with head and neck cancer

Patients with squamous cell carcinoma of the head and neck (SCCHN) have depressed antitumour immunity. The presence of CD4+CD25+ (T_reg) cells in these patients might be, in part, responsible for downregulation of antitumour immune responses. To evaluate the frequency and characteristics of T_reg in the peripheral circulation of patients with SCCHN, we used multicolour flow cytometry. Expression of CCR7, CD62L, ζ chain and Annexin V binding to T_reg and non-T_reg CD4+ lymphocyte populations were evaluated. T_reg were confirmed to be Foxp3+ and GITR+. The T_reg frequency was significantly elevated in patients with active disease and those with no evidence of disease (NED) following curative therapies. Both T_reg and non-T_reg CD4+ T cells in patients were significantly enriched in CCR7⁻ and CD62L⁻ cell subsets. Although T_reg in patients contained a higher proportion of double negative (CCR7⁻CD62L⁻) cells, the majority of T_regs were CCR7⁻CD62L+. The proportion of Annexin V+CD4+ T cells was higher in patients (P<0.00005) than normal controls (NC), and T_reg were significantly more sensitive to apoptosis than non-T_reg in patients and NC. Expression of ζ was reduced in all subsets of CD4+ T cells obtained from patients vs NC. The data suggest that T_reg in patients with SCCHN largely contain T cells with the ‘effector’ phenotype, which bind Annexin V and have low ζ expression, consistent with their activation state and a rapid turnover in the peripheral circulation.

[Ki-67 antisense therapy in murine renal cell carcinoma models]

PURPOSE

The Ki-67 antigen is only expressed in proliferating cells. Previously, it was shown that Ki-67 derived antisense oligonucleotides (asONs) specifically inhibit the proliferation of tumor cells and tumour growth in vitro and in subcutaneous bladder and prostate tumor models. We intended to evaluate the effects of this therapeutic concept in two renal cell carcinoma (RCC) models.

MATERIAL AND METHODS

Human RCC cells (SK-RC 35) were initially transfected with FITC-labeled ONs and diffferent cationic lipids to analyze the transfection efficacy by flow cytometry (FACS). The potency of 14 different ONs sequences was compared by quantitative RT-PCR in vitro. For in vivo testing, ONs were administered to immunocompetent Balb/c mice bearing orthotopic RENCA tumors as well as to SCID mice bearing subcutaneous RCC SK-RC 35 xenografts. Tumor sizes and final tumor weights were documented. Additionally, several immunohistochemical staining procedures were performed.

RESULTS

FACS analysis showed highly effective transfection conditions in vitro. Systemic administration of asONs significantly decreased the tumour growth in the RENCA model (p < 0.05) and in the SCID mouse model (p = 0.009). Immunohistochemical staining of tumor specimens revealed a marked down-regulation of target protein and a slight increase in apoptotic cells after antisense treatment while the microvessel count was not significantly altered.

CONCLUSION

These results demonstrate that the Ki-67 antigen represents a suitable antiproliferative target and that asONs directed against this target are potent drugs that induce a significant inhibition of renal tumor growth in different mouse models.

[Molecular biology of cystinuria]

Cystine stones belong to the kidney stones diseases which are difficult to manage due to the high rate of recidivation and the necessary surgical procedures. Cystinuria is an autosomal recessive defect of the transport of cystine and the dibasic amino acids in the proximal kidney tube. Recently, two subunits of a renal cystine transporter have been identified. Mutations in these genes have been shown to lead to the cystinuria phenotype. Genetic and functional analyses have helped to modify the classification of cystinuria which had previously been exclusively based on biochemical data. Furthermore, first steps towards a molecular genetic testing have been carried out replacing the so far diagnostic procedure which are stressing for the patients. The results of these testings make an individual therapy possible.

Analysis of the genes SLC7A9 and SLC3A1 in unclassified cystinurics: mutation detection rates and association between variants in SLC7A9 and the disease

Cystinuria is a common inherited disorder of defective renal reabsorption of cystine and dibasic amino acids. Recently, 2 responsible genes have been identified: mutations in the SLC3AI gene encoding the glycoprotein rBAT cause cystinuria type I, while variants in the SLC7A9 gene have been demonstrated in non-type I cystinuria; its gene product b(0)+AT is the light chain of the renal cystine transport system rBAT/b(0),+-AT. To estimate the role of both genes in the etiology of cystinuria, we searched for sequence alterations in SLC7A9 and SLC3AI: 30 unclassified cystinurics were investigated. In 50% of patients (15/30), point mutations in SLC3A1 were detected. Screening of the SLC7A9 gene revealed 10 mutations in 8 patients corresponding to a frequency of 27%. In addition to previously published mutations in the SLC7A9 gene, we detected 2 new mutations (F 140S, c747delG). An overall detection rate of 73% (22/30) in unclassified patients is delineated for mutations in both genes. In 33% (10/30), 2 mutations were detected, in 40% (12/30) 1 mutation. Furthermore, 5 new polymorphic sites were identified in SLC7A9. While the base pair variation in intron 9 is homogeneously distributed in patients and control individuals, the allelic and genotypic distributions of the polymorphisms in 3 exons of SLC7A9--exons 2, 5 and 6--and intron 3 differ significantly between both groups. Our results suggest that some haplotypes defined through the exons 2, 5 and 6 and intron 3 might be markers of a functional variant in the SLC7A9 gene. Evidently, since the mutation detection rates in the 2 so far known cystinuria genes never reach 100%, further genes and modulating factors should influence the phenotype in a subset of patients. However, the presented data show that testing for mutations in the 2 currently known cystinuria genes is already a meaningful approach to the molecular diagnostics of the disease.

Effects of the serine/threonine kinase SGK1 on the epithelial Na(+) channel (ENaC) and CFTR: implications for cystic fibrosis

Cystic fibrosis (CF) is characterized by impaired Cl(-) secretion and increased Na(+) reabsorption in several tissues including respiratory epithelium. Many CFTR mutations have been identified over the past years. However, only a poor correlation between the genotype and lung phenotype was found suggesting additional factors influencing the phenotype and course of the disease. The serine/threonine kinase SGK1 has recently been shown to stimulate the activity of the epithelial Na(+) channel ENaC. A variety of stimuli such as aldosterone, cell shrinkage, insulin or TGF-beta1 stimulate transcription and activate the SGK1 kinase. Here we further examined the effects of SGK1 on ENaC and CFTR which have mutual interactions and we analyzed sgk1 mRNA abundance in lung tissue from CF patients. Coexpression of CFTR and h-SGK1 in Xenopus oocytes increased ENaC currents as previously described. In addition CFTR mediated currents were also stimulated. h-SGK1 accelerated the expression of the amiloride sensitive Na(+)- current in Xenopus oocytes paralleled by increased ENaC-protein abundance in the oocyte membrane, an effect which was reversed by a h-SGK1(K127R) mutation lacking the ATP-binding site. The cation selectivity or Na(+) affinity were not affected. However, coexpression of h-SGK1 with ENaC altered the sensitivity of the Na(+)-channel to the inhibitors amiloride and triamterene. The inhibitory effect of CFTR expression on ENaC current was not affected by coexpression of h-SGK1 in Xenopus oocytes. Lung tissue from CF patients strongly expressed the serine/threonine kinase h-sgk1 which was not the case for non-CF lung tissue. Loss of CFTR function itself in a CF lung epithelial cell line did not increase SGK1 expression. In summary, enhanced expression of h-SGK1 in epithelial cells of CF-lung tissue may be a novel pathophysiological factor contributing to increased Na(+) channel activity and thus to increased Na(+) transport in CF.

Na+ transport by the neural glutamine transporter ATA1

Transfer of glutamine between astrocytes and neurons is an essential part of the glutamate-glutamine cycle in the brain. Here we have investigated how the neural glutamine transporter (rATA1/GlnT) works. Rat ATA1 was expressed in Xenopus laevis oocytes and examined using two-electrode voltage-clamp recordings, ion-sensitive microelectrodes and tracer flux experiments. Glutamine transport via rATA1 was electrogenic and caused inward currents that did not reverse at positive holding potentials. Currents were induced by a variety of neutral amino acids in the following relative order Ala>Ser/Gln/Asn/His/Cys/Met >MeAIB/Gly>Thr/Pro/Tyr/Val, where MeAIB is the amino acid analogue N-methylaminoisobutyric acid. The uptake of glutamine and the corresponding currents depended on Na+ and pH. Hill-coefficient and flux studies with 22NaCl indicated a cotransport stoichiometry 1 Na+ per transport cycle. The transporter also showed uncoupled Na+ transport, particularly when alanine was used as the substrate. Although substrate uptake increased strongly with increasing pH, no change of intracellular pH was observed during transport. A decrease of the intracellular pH similarly inhibited glutamine transport via ATA1, suggesting that the pH dependence was an allosteric effect on the transporter.

Therapeutic vaccination against metastatic carcinoma by expression-modulated and immunomodified autologous tumor cells: a first clinical phase I/II trial

Therapeutic vaccination of tumor patients with cytokine gene-transfected tumor cells leads to tumor regression in animal models but has so far not resulted in significant clinical benefit. We and others demonstrated that tumor cells transfected to mediate overexpression of a cytokine gene activate immunologic effector cells for an improved proliferation rate and significantly higher antitumoral cytotoxic activity. Here, we performed a pilot study of therapeutic vaccination in patients with metastatic disease. Autologous tumor cells were simultaneously transfected with novel minimalistic, immunogenically defined, gene expression constructs (MIDGE) for overexpression of the two cytokines interleukin 7 (IL-7) and GM-CSF and newly designed double stem-loop immunomodulating oligodeoxyribonucleotides (d-SLIM) as a Th1-promoting and NK cell-stimulating adjuvant. Transfection was performed ex vivo by ballistomagnetic gene transfer. Patients received four subcutaneous injections of at least 1 x 10(6) of their expression-modulated and immunomodified autologous tumor cells. Ten patients have been enrolled in the study protocol. In all patients no adverse effects could be detected. IL-7 and interferon gamma levels were elevated in the serum of the patients after treatment. Interestingly, cytotoxicity of patient-derived PBLs increased significantly during treatment. All 10 patients had progressive disease when entering our protocol. One complete, one partial, and one mixed response with progression of abdominal metastases and regression of lung metastases were observed. Two patients showed a stable disease after treatment and five patients remained in progressive disease. Our observations confirm the capability of autologous expression-modified and immunomodulated tumor cell vaccines to stimulate a strong immune response in patients with metastatic cancer even in the presence of a large tumor burden.

Identification of interstitial maternal uniparental disomy (UPD) (14) and complete maternal UPD(20) in a cohort of growth retarded patients

The association of uniparental disomy (UPD) and short stature has been reported for different chromosomes and in several conditions. Therefore, we investigated a cohort of 21 patients referred because of intrauterine and postnatal growth retardation for UPD of chromosomes 2, 7, 9, 14, 16, and 20. Typing of short tandem repeats showed maternal UPD(14) and maternal UPD(20) in two cases. In the first case, an interstitial UPD(14) was detected and the growth retarded newborn showed some additional clinical signs in common with the putative "maternal UPD(14) syndrome". The maternal UPD(20) patient showed minor features. However, since it is only the second maternal UPD(20) case it is too early to delineate a specific syndrome and the role of this constitution in growth remains to be investigated. Our data suggest that searching for UPD in growth retarded patients is a helpful approach to getting more information on the role of UPD in growth retardation. Based on our results, general considerations and indications for UPD testing are discussed.

The heterodimeric amino acid transporter 4F2hc/LAT1 is associated in Xenopus oocytes with a non-selective cation channel that is regulated by the serine/threonine kinase sgk-1

System L is the major Na(+)-independent amino acid transporter of mammalian cells. It is constituted of the type II membrane protein 4F2hc (CD98) which is covalently linked to the polytopic membrane protein LAT1 via a disulfide bridge. The transporter is known to be regulated by the mineral corticoid aldosterone in Xenopus A6 cells. To understand the regulation of the transporter, the 4F2hc/LAT1 heterodimer was functionally expressed in Xenopus laevis oocytes and its transport properties were analysed using flux measurements and the two-electrode voltage-clamp technique. Expression of 4F2hc/LAT1 resulted in a rapid increase in a Na(+)-independent neutral amino acid antiport activity and simultaneously gave rise to a cation conductance. The cation channel was non-rectifying and non-selective, conducting Li(+) > Cs(+) = Na(+) > K(+). After replacement of Na(+) by NMDG, however, the currents were suppressed almost completely. The cation channel was not inhibited by amiloride, Ba2(+), TEA, Hoe293B, flufenamic acid or substrates of the system L amino acid transporter. Significant inhibition, however, was observed in the presence of La3(+), Gd3(+) and quinidine. Channel activity was upregulated by coexpression of 4F2hc/LAT1 with the aldosterone-regulated protein kinase sgk-1. The cation conductance was sensitive to changes in the redox potential, being inhibited following incubation of the oocytes with DTE for 30 min. Mutation of either of the disulfide bridge-constituting cysteines to serine resulted in a loss of ion channel activity whereas amino acid transport was unaffected. It is concluded that the 4F2hc/LAT1 heterodimer regulates a closely associated cation channel or even constitutes a cation channel itself.

Mutations in the SLC3A1 gene in cystinuric patients: frequencies and identification of a novel mutation

Cystinuria is a frequent autosomal recessive transport disorder characterized by defective renal resorption of cystine and other dibasic amino acids. Biochemically, three types of cystinuria can be defined. Here we present our results of screening for mutations in the SLC3A1 gene, which codes for a dibasic amino acid transporter protein and appears to be involved in the pathogenesis of cystinuria type I. Our study population consists of 5 Italian cystinuria type I patients and 10 cystinuric patients as yet unclassified as to clinical type. The latter were of different ethnic origin. In total, we found 13 point mutations and 8 genomic rearrangements in 15 cystinuric patients, i.e., our detection rate was 70% (23/30 chromosomes). Remarkably, in patients known to be suffering from cystinuria type I, the mutation detection rate was only 50%, whereas in patients unselected as to cystinuria type, we found 80% of mutations. Additionally, our results, as with those published in the literature, indicate a possible population specific distribution of mutations: Each of the 4 Greek patients analyzed here showed homozygosity for mutation T216M in exon 3. Analysis of a Yugoslavian patient showed homozygosity for a novel mutation, R365L, in exon 6 (nt1094G > T). Findings from molecular genetic studies, as well as physiological investigations, suggest that there are further genes that play a role in the etiology of cystinuria. Nevertheless, our results show that screening for mutations in the SLC3A1 gene can be a meaningful step toward molecular genetic diagnosis of cystinuria in patients without biochemical classification. As with cystic fibrosis, the finding of specific mutations in particular ethnic populations, suggest that the diagnostic approach should take into consideration a patient's ethnic origins.

Retinoic acid receptor gamma1 expression determines retinoid sensitivity in pancreatic carcinoma cells

BACKGROUND & AIMS

Retinoids inhibit growth and induce differentiation in a variety of pancreatic carcinoma cells. The goal of this study was to examine the molecular mechanisms responsible for retinoid sensitivity.

METHODS

Anchorage-independent growth was examined in AR42J, DSL-6A/C1, and Capan-2 cells using a human tumor clonogenic assay. Retinoid receptors were characterized by a reverse-transcription polymerase chain reaction. Retinoic acid receptor gamma1 (RARgamma1) was stably transfected into AR42J cells using lipofectamin and into DSL-6A/C1 using ballistomagnetic gene transfer. Receptor expression was verified using Southern and Northern blotting as well as electrophoretic mobility shift assays.

RESULTS

Retinoid treatment resulted in a dose-dependent growth inhibition of Capan-2 cells, whereas growth was not affected in AR42J and DSL-6A/C1 cells. A selective loss of RARgamma1 expression was observed in both retinoid-resistant cell lines, whereas all other retinoid receptor subtypes showed an identical expression pattern. Retinoid treatment of three independent RARgamma1-expressing cell clones of AR42J and DSL-6A/C1 cells resulted in pronounced growth inhibition compared with wild-type control cells.

CONCLUSIONS

RARgamma1 expression determines sensitivity of pancreatic carcinoma cells to retinoid-mediated growth inhibition and might therefore serve as a valuable predictive marker for retinoid treatment of pancreatic cancer.

Optimized non-radioactive protein truncation test for mutation analysis of the adenomatous polyposis coli (APC) gene

Germline mutations in the adenomatous polyposis coli gene cause familial adenomatous polyposis, a colon cancer predisposition syndrome. More than 95% of the identified mutations result in the generation of stop codons or reading frame shifts and encode a truncated gene product, a mutation profile also found in other tumor predisposition genes such as the breast cancer or the hereditary non-polyposis coli. Therefore the protein truncation test is ideally suited for screening of mutations in these genes, starting from simple blood samples. Gene segments of interest are amplified from genomic DNA or mRNA, thereby incorporating a T7 promoter at the 5'-end. After in vitro transcription and translation of the PCR products, the resulting protein is analysed by gel electrophoresis. Truncated translation products indicate the presence of a stop mutation. We have developed a non-radioactive protein truncation test that uses a biotinylated Lys-t-RNA to label the translation products and allows a chemiluminescent detection instead of the standard radioactive method. This generic protein truncation test kit was then used to develop a parameter-specific protein truncation test for adenomatous polyposis coli. The adenomatous polyposis coli gene was divided in 5 overlapping segments, and primers were optimized to produce distinct bands with very low background in the protein truncation test. The assay was tested on 20 familial adenomatous polyposis patient samples, where 18 mutations were found, demonstrating the efficiency of this method.

Cell adhesion to the apical pole of epithelium: a function of cell polarity

Human uterine epithelium displays a distinct polarized organization with apical, lateral, and basal plasma membrane domains. Although non-adhesive throughout most of the menstrual cycle, epithelial cells allow attachment of trophoblast cells to their apical pole during embryo implantation. A recent hypothesis postulates that epithelial cells turn off genes for apical-basal polarity and turn on genes for a more mesenchyme-like phenotype allowing cell-cell interaction with trophoblast. Using an in vitro assay human uterine cell lines (RL95-2, HEC-1-A, AN3-CA) were selected on the basis of adhesiveness for trophoblast-type cells (JAR). Subsequently, uterine cells were examined for epithelium-specific ultrastructure using transmission electron microscopy, and for the expression of E-cadherin, alpha 6-, beta 1-, beta 4-integrin subunits and cytokeratin using immunocytochemistry, confocal laser scanning microscopy, and surface replication technique. HEC-1-A monolayers are non-adhesive for JAR cells and appear highly polarized expressing E-cadherin, alpha 6-, beta 1-, beta 4-integrin subunits, and cytokeratin. Both, integrins and E-cadherin, are present at the lateral membrane. RL95-2 monolayers which are adhesive for JAR cells appear non-polarized. Like HEC-1-A cells, RL95-2 cells express E-cadherin, alpha 6-, beta 1-, and beta 4-integrin subunits, and cytokeratin. In contrast to HEC-1-A cells, integrins and E-cadherin are distributed at the entire cell surface. AN3-CA monolayers are non-adhesive for JAR cells and appear non-polarized. Cells lack epithelial-specific markers such as keratin and E-cadherin. They show only low expression of alpha 6-, beta 1-integrin subunits and lack beta 4-integrin subunit. Conversely, they express vimentin. Thus, modulation of the epithelial phenotype of uterine cells, i.e. loss of apical-basal polarity, might prepare the apical cell pole for cell-cell interaction with trophoblast. However, loss of cell polarity would not lead to enhancement of adhesiveness for trophoblast if accompanied by a loss of epithelium-specific adhesion molecules.

Differential expression and localization of integrins and CD44 in the membrane domains of human uterine epithelial cells during the menstrual cycle

Human uterine epithelium displays a distinctly polarized organization with basal, lateral, and apical plasma membrane domains. Although nonadhesive throughout most of the menstrual cycle, uterine epithelial cells allow attachment of trophoblast cells to their apical pole during embryo implantation. Development of the receptive state might involve expression of cell adhesion molecules and/or redistribution of such molecules with respect to their localization at the basal, lateral, and apical membrane domains of cells. Expression and distribution of alpha 1-, alpha 3-, alpha 5-, alpha 6-, beta one-, beta 3- and beta 4-integrin subunits as well as of CD44 were examined in the luminal epithelium of human endometrium by immunohistochemistry in different phases of the menstrual cycle. The luminal epithelium was found to express alpha 1-, alpha 3-, alpha 6-, beta 1-, beta 4-integrin subunits and CD44. alpha l6-Integrin subunits and CD44 displayed cycle dependency. The alpha 6-integrin subunits were detected in the basal membrane domains in all phases. However, in correlation with increasing expression during the secretory phase of cycle, these subunits newly appeared in the lateral membranes of epithelial cells. CD44 showed increased expression in the secretory phase but was always restricted to the lateral membranes. The conspicuous behavior of alpha 6-integrin subunits and CD44 is discussed with respect to its possible functional significance for embryo implantation, and in relation to a hypothesis postulating that steroid-controlled master genes direct the acquisition of the receptive state of the luminal uterine epithelium by changing elements of the apicobasal polarity of these cells.