[The diagnostic framework for screening Alzheimer's disease in the Chinese population].

Criteria for diagnosis of Alzheimer's disease (AD) is not available in China. The international criteria is not a proper choice due to issues such as translation and lead to low diagnostic rate and high rate of missed diagnosis. The research group of Alzheimer's Disease Chinese (ADC) reviewed knowledge and techniques in neuropsychology, neuroimaging, molecular biology, and clinical neurology, and systematically studied the detection techniques such as memory, language, visuospatial, executive function, and medial temporal lobe visual scores on MRI, and their optimal threshold and diagnostic value for the diagnosis of AD. Through a systematic review and consensus meeting, a diagnostic framework for screening AD in the Chinese population was established. Among these methods, an operational standard for clinical pathology models increased the diagnostic sensitivity by 15%. The sensitivity and specificity of screening memory impairment increased by 18.1% and 11.6%, respectively. The sensitivity of screening medial temporal lobe atrophy increased by 24.5% and missed diagnosis was decreased by 34.5%. An operational standard for clinical biology models, incorporating the latest molecular imaging and molecular biology techniques, has enabled the early diagnosis of AD in China. The framework combines a principled diagnostic guideline with an operational screening protocol, which is applicable to all clinical settings and of great significance for the early detection, early diagnosis and early treatment of AD.

Combination of a novel photosensitizer DTPP with 650 nm laser results in efficient apoptosis, arresting cell cycle and cytoskeleton protein changes in lung cancer A549 cells.

Photodynamic therapy (PDT) using photosensitized reaction to produce cytotoxicity was used for cancer therapy in recent years. To study the effectiveness of PDT mediated by a novel photosensitizer (PS), DTPP 5-(4'-(2″-dicarboxymethylamino)acetamidophenyl)-10, 15, 20-triphenylporphyrin, on lung cancer A549 cell lines in vitro, DTPP was employed in different concentrations (2, 4, 6, 8, 10, 12, 15, 20, 25, and 30 µg/ml) and combined with 650 nm laser of different power densities (0.6, 1.2, 2.4, 4.8, 7.2, and 9.6 J/cm(2)) that resulted in obvious inhibition of cell proliferation and apoptosis. Results showed that cell survival rates have a dependent relationship with time and PS concentrations and no significant cytotoxicity was induced by DTPP itself. Apoptosis and cell cycle S arrest were observed; cytoskeleton morphologic observation revealed collapse, sparkling, and shrunken shapes. Apoptosis-related protein caspase-3 overexpression was detected while caspase-9, bcl-2, and cytoskeleton protein beta-catenin were in low levels of expression than the control. Cleavage of beta-catenin by caspase-3 or other proteases from the lysosome might be the main reason for the cytoskeleton collapse as beta-tubulin and actin were at a stable level 12 h after PDT. This paper gives a better understanding of the effectiveness of DTPP-mediated PDT in lung cancer A549 cells both with regard to dosimetry and apoptosis changes.

Potential roles for prions and protein-only inheritance in cancer.

Inherited mutations are known to cause familial cancers. However, the cause of sporadic cancers, which likely represent the majority of cancers, is yet to be elucidated. Sporadic cancers contain somatic mutations (including oncogenic mutations); however, the origin of these mutations is unclear. An intriguing possibility is that a stable alteration occurs in somatic cells prior to oncogenic mutations and promotes the subsequent accumulation of oncogenic mutations. This review explores the possible role of prions and protein-only inheritance in cancer. Genetic studies using lower eukaryotes, primarily yeast, have identified a large number of proteins as prions that confer dominant phenotypes with cytoplasmic (non-Mendelian) inheritance. Many of these have mammalian functional homologs. The human prion protein (PrP) is known to cause neurodegenerative diseases and has now been found to be upregulated in multiple cancers. PrP expression in cancer cells contributes to cancer progression and resistance to various cancer therapies. Epigenetic changes in the gene expression and hyperactivation of MAP kinase signaling, processes that in lower eukaryotes are affected by prions, play important roles in oncogenesis in humans. Prion phenomena in yeast appear to be influenced by stresses, and there is considerable evidence of the association of some amyloids with biologically positive functions. This suggests that if protein-only somatic inheritance exists in mammalian cells, it might contribute to cancer phenotypes. Here, we highlight evidence in the literature for an involvement of prion or prion-like mechanisms in cancer and how they may in the future be viewed as diagnostic markers and potential therapeutic targets.

Characterization of lactic acid bacteria-based probiotics as potential heavy metal sorbents.

AIM: To isolate and characterize lactic acid bacteria (LAB) and determine whether they could potentially be used as heavy metal (cadmium and lead) absorbing probiotics. METHODS AND RESULTS: The study used 53 environmental (mud and sludge) samples to isolate cadmium- and lead-resistant LAB, by following spared plate technique. A total of 255 cadmium- and lead-resistant LAB were isolated from these samples. The survival of 26 of the LAB was found after passing through sequential probiotic characterizations. These 26 probiotic LAB exhibited remarkable variations in their metal-resistant and metal-removal abilities. Of 26, seven (Cd54-2, Cd61-7, Cd69-12, Cd70-13, Pb82-8, Pb96-19 and Cd109-16) and four (Pb71-1, Pb73-2, Pb85-9 and Pb96-19) strains displayed relatively elevated cadmium- and lead-removal efficiencies from water, respectively, compare with that of the remaining strains. Strains Cd70-13 and Pb71-1 showed the highest cadmium (25%) and lead (59%) removal capacity from MRS (De Man, Rogosa and Sharpe) culture medium, respectively, amongst the selected strains and showed a good adhesive ability on fish mucus. A phylogenetic analysis of their 16S rDNA sequences revealed that the strains Cd70-13 and Pb71-1 belong to Lactobacillus reuteri. CONCLUSION: Excellent probiotic, metal sorption and adhesive characteristics of newly identified Lact. reuteri strains Cd70-13 and Pb71-1 were isolated, which indicated their high potential abilities to survive in the intestinal milieu and to uptake the tested metals from the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first study that has aimed to isolate, characterize and identify metal-resistant LAB strains that have potential to be a probiotic candidate for food and in vivo challenge studies in the intestinal milieu of fish for the uptake and control of heavy metal bioaccumulation.

Cardiovascular disease in rheumatoid arthritis: medications and risk factors in China.

This study aims to assess the risk factors of cardiovascular disease (CVD) and to determine the association of traditional and biologic disease-modifying anti-rheumatic drugs (DMARDs) with risk for CVD in Chinese rheumatoid arthritis (RA) patients. A cross-sectional cohort of 2013 RA patients from 21 hospitals around China was established. Medical history of CVD was documented. The patients' social background, clinical manifestations, comorbidities, and medications were also collected. Of the 2013 patients, 256 had CVD with an incidence of 12.7%. Compared with non-CVD controls, RA patients with CVD had a significantly advanced age, long-standing median disease duration, more often male and more deformity joints. Patients with CVD also had higher rates of smoking, rheumatoid nodules, interstitial lung disease, and anemia. The prevalence of comorbidities, including hypothyroidism, diabetes mellitus (DM), hypertension, and hyperlipidemia, was also significant higher in the CVD group. In contrast, patients treated with methotrexate, hydroxychloroquine (HCQ), and TNF blockers had lower incidence of CVD. The multivariate analysis showed that the use of HCQ was a protective factor of CVD, while hypertension, hyperlipidemia, and interstitial lung disease were independent risk factors of CVD. Our study shows that the independent risk factors of CVD include hypertension, hyperlipidemia, and interstitial lung disease. HCQ reduces the risk of CVD in patients with RA.

Lentiviral vector-mediated tyrosinase-related protein 2 gene transfer to dendritic cells for the therapy of melanoma.

Dendritic cells (DCs) are the most potent professional antigen-presenting cells (APCs), which play a vital role in primary immune responses. Introducing genes into DCs will allow constitutive expression of the encoded proteins and thus prolong the presentation of the antigens derived therefrom. In addition, multiple and unidentified epitopes encoded by the entire tumor-associated antigen (TAA) gene may enhance T cell activation. This study demonstrated that an HIV-1-based lentiviral vector conferred efficient gene transfer to DCs. The transgene, murine tyrosinase-related protein 2 (mTRP-2), encodes a clinically relevant melanoma-associated antigen (MAA), which has been found to be a tumor rejection antigen for B16 melanoma. The transfer and proper processing of mTRP-2 in DCs, in terms of RNA transcription activity and protein expression, were verified by RT-PCR and specific antibody, respectively. Administration of mTRP-2 gene-modified DCs (DC-HR' CmT2) to C57BL/6 mice evoked strong protection against tumor challenge, for which the presence of CD4+ and CD8+ cells during both the priming and challenge phase was essential. In a therapy model, our results showed that four of seven mice with preestablished tumor remained tumor free for 80 days after therapeutic vaccination. Given the results shown in this study, mTRP-2 gene transfer to DCs provides a potential therapeutic strategy for the management of melanoma, especially in the early stage of the disease.

Antiapoptotic marker Bcl-X(L), expression on Reed-Sternberg cells of Hodgkin's disease using a novel monoclonal marker, YTH-2H12.

Inhibitors of apoptosis may regulate tissue differentiation and promote cell survival in neoplasia. A new apoptosis inhibitor of the bcl-2 gene family, bcl-X(L), was recently found in some types human neoplasia but not in normal tissue. We investigated bcl-X(L) expression in 419 cases of normal and neoplastic lymphoid lesions using immunohistochemistry with the monoclonal antibody bcl-X(L) (YTH-2H12). Ninety-four percent (141/150) of classic Hodgkin's disease (HD) were positive for bcl-X(L) with strong intensity in most Reed-Sternberg (RS) cells. Forty-eight percent (38/80) of nodular lymphocyte predominance (LPHD) were positive. In the non-Hodgkin's lymphomas (NHL), bcl-X(L) was expressed in a low percentage of cases (< 20%), with the exception of follicle center lymphoma, grade III/III (78%). All reactive hyperplastic lesions were negative for bcl-X(L). RS cells, which expressed bcl-X(L), were not labeled by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). We found RS cells expressing bcl-X(L) were absent of DNA fragmentation (apoptosis). Our data provide evidence that bcl-X(L) is abnormally expressed in the RS cells of HD and some types of NHL raising speculation that inhibition of apoptosis may be important in the pathogenesis of lymphoma, specifically HD. In addition, the previously reported correlation between bcl-X(L) and Epstein-Barr virus expression in HD was not supported by this study.

Typing of methicillin-resistant Staphylococcus aureus with IS256.

A simple one-step procedure is described for specifically amplifying and labelling insertion element IS256 which is associated with the gentamicin-resistance transposon Tn4001. The product has been used to probe DNA digests of methicillin-resistant Staphylococcus aureus. The resulting restriction fragment length polymorphisms were found to be able to distinguish isolates which were indistinguishable by other typing methods. The probe also hybridised with methicillin-resistant Staphylococcus aureus which were isolated before the emergence of gentamicin resistance, demonstrating its usefulness in typing species other than those that are gentamicin-resistant.

Conjugative trimethoprim resistance in Staphylococcus aureus.

A multiply resistant Staphylococcus aureus isolate, WBG7410, harbours plasmids of 38, 26, 2.8, 2.4 and 1.9 kb and transfers trimethoprim and kanamycin resistance at high frequencies by conjugation. The transconjugants contained the 38-kb plasmid, pWBG707, and the 2.8-kb plasmid. Plasmid pWBG707 was shown to encode trimethoprim resistance, was conjugative and mobilised at high frequencies the 2.8-kb plasmid which presumably encodes kanamycin resistance. Plasmid pWBG707 was isolated mostly in the open circular form and analysis with EcoRI restriction endonuclease suggests that pWBG707 is a new conjugative plasmid distinct from the other conjugative plasmids reported in S. aureus.

Typing of Australian methicillin-resistant Staphylococcus aureus strains by pulsed field gel electrophoresis.

Twenty-six clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) collected from six Australian hospitals by a National Staphylococcal Study Group were examined by analysis of restriction fragment length polymorphisms (RFLPs) of chromosomal DNA with pulsed field gel electrophoresis. Digestion with the restriction endonuclease SmaI produced 13-17 bands of 7-700 kb. The digestion patterns were easily distinguished and isolates could be classified into 17 groups based on their RFLPs. Isolates giving a pattern associated with one group were from four hospitals in four different states. In another group, the isolates responsible were from three hospitals in two states and in a further group, the isolates were derived from two hospitals in different states. The remaining groups comprised only one member each. The method has promise for typing and studying the epidemiology of MRSA.

Use of contour-clamped homogeneous electric field (CHEF) electrophoresis to type methicillin-resistant Staphylococcus aureus.

Strains of methicillin-resistant Staphylococcus aureus (MRSA) from Australia and the UK were compared by digesting their chromosomal DNA with the low-frequency-cutting restriction enzyme SmaI and separating the restriction fragment length polymorphisms (RFLPs) by contour-clamped homogeneous electric field (CHEF) electrophoresis. The numbers of restriction fragments produced were in the range 14-17 and the sizes of the bands were 7-700 kb. Generally, the results confirmed previous conclusions based on antimicrobial resistance and plasmid profiles. The earlier MRSA isolates were different from more recent isolates, and the epidemic MRSA from eastern Australia (EA MRSA) was the same as the epidemic MRSA (EMRSA) found in London hospitals. However, contrary to previous results, the EA MRSA did not constitute a homogeneous group. The results showed that comparison of RFLPs by CHEF electrophoresis is a useful technique for studying the epidemiology of MRSA.

Typing of methicillin-resistant Staphylococcus aureus with an M13 repeat probe.

A bacteriophage M13 tandem repeat has been used to probe EcoRI digested genomic DNA of methicillin-resistant Staphylococcus aureus (MRSA). The patterns generated were found to be useful in typing MRSA and generally confirmed the relationships that had previously been recognized in other studies based on antimicrobial resistance and plasmid profiles. The epidemic MRSA of London hospitals (EMRSA) and the majority of the epidemic MRSA of eastern Australian hospitals (EA MRSA) gave the same pattern. However, two isolates previously classified as EA MRSA gave a different pattern and a third another pattern. One isolate from Dublin, two isolates from Nuneaton and two isolates from Singapore gave the same pattern as the two EA MRSA. With the exception of the early or classic MRSA all the other isolates examined gave their own distinctive patterns. With one exception the classic MRSA belonged to a separate group. The exception was of particular interest because it gave the same pattern as the majority of the EA MRSA. This suggests that there may be an evolutionary relationship between some of the classic MRSA and the EMRSA of London and the EA MRSA of Australia.

Development of disabled, replication-defective gene transfer vectors from the Jembrana disease virus, a new infectious agent of cattle.

Jembrana disease virus (JDV) is a newly isolated and characterised bovine lentivirus. It causes an acute disease in Bali cattle (Bos javanicus), which can be readily transmitted to susceptible cattle with 17% mortality. There is as yet no treatment or preventive vaccine. We have developed a gene transfer vector system based on JDV that has three components. The first of the components is a bicistronic transfer vector plasmid that was constructed to contain cis-sequences from the JDV genome, including 5'- and 3'-long terminal repeats (LTRs), 0.4kb of truncated gag and 1.1kb of 3'-env, a multiple cloning site to accommodate the gene(s) of interest for transfer, and an internal ribosome entry site plus the neomycin phosphotransferase (Neo) gene cassette for antibiotic selection. The second element is a packaging plasmid that contains trans-sequences, including gag, pol, vif, tat and rev, but without the env and packaging signals. The third is a plasmid encoding the G glycoprotein of vesicular stomatitis virus (VSV-G) to supply the vector an envelope for pseudotyping. Cotransfection of 293T cells with these three plasmid components produced VSV-G pseudotyped, disabled, replication defective, bicistronic JDV vectors encoding the green fluorescent protein (EGFP) and the Neo resistance selection maker simultaneously with a titre range of (0.4-1.2)x10(6)CFU/ml. Transduction of several replicating primary and transformed cells from cattle, primate and human sources and importantly growth-arrested cells with the JDV vectors showed high efficiency of EGFP gene transfer at 35-75%, which was stable and the expression of EGFP was long term. Furthermore, these JDV vectors were designed to suit the inclusion and expression of genes corresponding to JDV specific proteins, such as gag or env, for the development of vaccines for Jembrana disease. This strategy should also be applicable to other bovine diseases as well. The design and construction of the JDV vector system should facilitate the study of the lentivirology and pathogenesis of the diseases associated with JDV or other bovine virus infections. To our knowledge, this is the first such vector system developed from a cattle virus.

Combination of a novel photosensitizer DTPP with 650 nm laser results in efficient apoptosis and cytoskeleton collapse in breast cancer MCF-7 cells.

Luminal A type breast cancer was suitable for Photodynamic therapy (PDT) as its strong adhesion ability, low malignancy and easily being exposed to laser. To examine the novel photosensitizer agent 5-5-(4-N, N-diacetoxylphenyl-10, 15, 20-tetraphenylporphyrin)(DTPP) mediate PDT in breast cancer cell, Luminal A type breast cancer MCF-7 cells were used in this study, various concentrations of DTPP (0, 2, 4, 6, 8, 10, 12, 15, 20, 25, 30 µg/mL) and different time intervals (0, 0.5, 1, 2, 4, 6, 8 min) of laser exposure at 650 nm wavelength (power of 20 mW) were tested in PDT. The survival rates of MCF-7 cells were measured using a sensitive cell proliferation assay (MTT) to establish optimal semilethal dose and optimal time exposure, a further study of effects on cytoskeleton and apoptosis were also performed. Cell cycle and apoptosis variation were assayed by flow cytometry. Microtubule, microfilament, and nuclei were observed using laser scanning confocal microscopy. Oncoproteins Bcl-2, beta-tubulin, and beta-catenin were detected by means of electrophoresis. The novel DTPP showed an efficient growth inhibition of MCF-7 during PDT, effective combinations in MCF-7 cells were shown to be 4 µg mL(-1) PS irradiated for 8 min at least or 15 µg mL(-1) irradiated for 2 min at least. Microtubule, microfilament, and nucleus staining demonstrated that cytoskeletal collapse occurs at 0.5 h after PDT. Bcl-2 and skeleton adhesion proteins beta-catenin were reduced in the level of expression; whereas, skeleton proteins beta-tubulin and actin maintained similar levels of expression 12 h after PDT. These results provided a better understanding of DTPP-PDT in MCF-7 cells.

Effects of metoprolol and small intestine RNA on marrow-derived endothelial progenitor cells applied for autograft transplantation in heart disease.

AIMS: The objective of this project was to improve the effect of EPC autograft transplantation and observe the tolerance of EPCs to I/R injury affected by metoprolol and small intestine RNA. MATERIALS AND METHODS: We isolated bone marrow-derived EPCs and examined the effects of metoprolol and small intestine RNA on EPCs to ischemia at different time points after reperfusion. EPCs growth curve, secretion, apoptosis and mortality were also analyzed. RESULTS: EPCs will be better protected if the blood can be recovered within 4 hours after ischemia for cardiac muscle cells and pretreatment of EPCs with metoprolol or small intestine RNA could protect and promote EPCs proliferation. CONCLUSIONS: Our study demonstated that pretreatment of EPCs with metoprolol or small intestine RNA will increase the EPCs proliferation and may improve the EPCs autograft transplantation ability.

Immunotoxin-mediated targeting of claudin-4 inhibits the proliferation of cancer cells.

Immunotoxins are engineered chimeric proteins that consist of a fragment of a toxin fused to a modified antibody or growth factor capable of targeting specific cells. Furthermore, these proteins can be targeted to receptors that are commonly overexpressed on cancer cells. The majority of immunotoxins function by binding to cells, translocating into the cytosol and inhibiting protein synthesis. In this study, the expression of claudin­4 (CLDN4) in various cancer cells was analysed as a potential target for immunotoxins. To target CLDN4-expressing cancer cells, the c-terminal CLDN4­binding domain of Clostridium perfringens enterotoxin (CPE) was fused to the Pseudomonas aeruginosa exotoxin A (ETA) domain to create an immunotoxin (CPE­ETA'). Subsequently, the capacity of such an immunotoxin in suppressing the proliferation of CLDN4-positive cancer cells was investigated. We report that head and neck squamous carcinoma cells (HN5) have an elevated CLDN4 expression compared to the other cell lines tested. Our findings further demonstrate that CPE­ETA' is highly potent against MCF-7 breast [50% inhibitory concentration (IC50) 9.8 ng/ml] and HN5 head/neck (IC50 8.8 ng/ml) cancer cell lines, while it has no cytotoxic effects on HeLa cells (CLDN4­negative). The immunotoxin was subsequently expressed in the tumour colonising oncolytic strain, Clostridium ghonii. Most importantly, the strictly anaerobic Clostridium ghonii was able to overexpress and secrete a functional CPE­ETA' fusion protein. Our findings open the possibility of the targeted delivery of the immunotoxin locally to tumour sites at a high concentration using strictly anaerobic Clostridium ghonii for the treatment of CLDN4-positive cancer cells.

Long-term correction of diabetes in rats after lentiviral hepatic insulin gene therapy.

AIMS/HYPOTHESIS: Type 1 diabetes results from the autoimmune destruction of pancreatic beta cells. Exogenous insulin therapy cannot achieve precise physiological control of blood glucose concentrations, and debilitating complications develop. Lentiviral vectors are promising tools for liver-directed gene therapy. However, to date, transduction rates in vivo remain low in hepatocytes, without the induction of cell cycling. We investigated long-term transgene expression in quiescent hepatocytes in vitro and determined whether the lentiviral delivery of furin-cleavable insulin to the liver could reverse diabetes in rats. MATERIALS AND METHODS: To improve transduction efficiency in vitro, we optimised hepatocyte isolation and maintenance protocols and, using an improved surgical delivery method, delivered furin-cleavable insulin alone or empty vector to the livers of streptozotocin-induced diabetic rats by means of a lentiviral vector. Rats were monitored for changes in body weight and blood glucose, and intravenous glucose tolerance tests were performed. Expression of insulin was determined by RT-PCR, immunohistochemistry and electron microscopy. RESULTS: We achieved long-term transgene expression in quiescent hepatocytes in vitro (87 +/- 1.2% transduction efficiency), with up to 60 +/- 3.2% transduction in vivo. We normalised blood glucose for 500 days-a significantly longer period than previously reported-making this the first successful study using a lentiviral vector. This procedure resulted in the expression of genes encoding several beta cell transcription factors, some pancreatic endocrine transdifferentiation, hepatic insulin storage in granules, and restoration of glucose tolerance. Liver function tests remained normal. Importantly, pancreatic exocrine transdifferentiation did not occur. CONCLUSIONS/INTERPRETATION: Our data suggest that this regimen may ultimately be employed for the treatment of type 1 diabetes.

High-titer bicistronic retroviral vectors employing foot-and-mouth disease virus internal ribosome entry site.

Bicistronic retroviral vectors were constructed containing the foot-and-mouth disease virus (FMDV) internal ribosome entry site (IRES) followed by the coding region of beta-galactosidase (beta-gal) or therapeutic genes, with the selectable neomycin phosphotransferase gene under the control of the viral long terminal repeat (LTR) promoter. LNFX, a vector with a multiple cloning site 3' to foot-and-mouth disease virus IRES, was used to construct vectors encoding rat erythropoietin (EP), rat granulocyte colony-stimulating factor (G-CSF), human adenosine deaminase (ADA) and beta-gal. In transduced primary rat vascular smooth muscle cells the cytokines were expressed at high levels, similar to those obtained from vectors employing the viral LTR promoter. LNFZ, a vector encoding beta-gal, had a 10-fold increase in titer over that of LNPoZ, a comparable vector containing the poliovirus (Po) internal ribosome entry site. Primary canine vascular smooth muscle cells infected with LNFZ and LNPoZ expressed similar activities of beta-gal and neomycin phosphotransferase (NPT). Overall, these vectors had titers between 10(6) and 2 x 10(7) c.f.u./ml, indicating that foot-and-mouth disease virus IRES provides high-titer bicistronic vectors with high-level two gene expression.

Silicone gel-filled breast and testicular implant capsules: a histologic and immunophenotypic study.

The immunophenotypic characteristics of silicone gel-filled breast and testicular implant capsules have not been well described. Therefore, we studied 17 paraffin-embedded tissue sections from 9 breast implant patients and 1 testicular implant patient to assess the type and extent of inflammatory responses present. Immunohistochemical analyses were performed on paraffin-embedded tissue sections for expression of CD20, CD45RO, betaF1, CD68, CD44, kappa and A immunoglobulin light chains, and bcl-XL (a member of the bcl-2 family of proteins involved in apoptosis). The most common histologic features included prominent T-cell and foamy macrophage reactions with foreign body giant cells and granulomas in a dense fibrovascular connective tissue. Foci of polyclonal plasma cells and acute inflammatory cells were variably present. In one case, there was reactive germinal center formation, a novel finding. A "pseudosynovium" at the implant capsule interface was present in the majority of cases as previously described; it showed reactivity with CD68. Thin strands of highly refractile, nonpolarizable material, consistent with silicone, were regularly noted in intra- and extracellular locations. The immunohistochemical results included reactivity of the majority of lymphocytes with CD45RO and/or betaF1 (confirming an anamnestic reactive T-cell phenotype), and reactivity of the macrophages, giant cells, and "pseudosynovium" with the macrophage/histiocyte marker, CD68. The reactive germinal centers were positive for CD20. Reactivity for CD44, an activation and intracellular adhesion marker, was frequently observed in the foamy macrophages and foreign body giant cells and has not been previously reported. The plasma cells demonstrated polyclonal immunoglobulin light-chain reactivity, consistent with a reactive process. These findings suggest that silicone implants induce chronic inflammatory responses in many adjacent capsules, which consist of anamnestically responding T cells, reactive B-lymphocytes, and macrophages.