Over-expression of anti-CD75 reactive proteins on distal and collecting renal tubular epithelial cells in calcium-oxalate stone-forming kidneys in Egypt.

OBJECTIVE: To assess the nature, distribution and expression pattern of CD75, a neuraminidase-sensitive lymphocyte cell surface differentiation antigen, in calcium oxalate (CaOx) stone disease, as cell-surface sialic acid might be involved CaOx crystal binding, and lectin-binding assays suggest that sialic acid in the alpha2,6 position is upregulated in stone-forming kidneys. MATERIALS AND METHODS: Human CaOx stone-forming and normal kidneys (13 each) and primary kidney epithelial cells (CAKI-1, three samples) were analysed. The protein pattern, distribution and expression of CD75 were analysed using Western blotting, immunohistology and semi-quantitative confocal laser scanning microscopy (cLSM). Production was investigated by alpha2,6-sialyltransferase specific reverse transcription-polymerase chain reaction. RESULTS: Western blotting showed one strong band at approximately 43 kDa that reacted with anti-CD75 when renal epithelial and CAKI-1 tumour cell extracts were analysed. However, in renal tissue extracts of CaOx stone formers there were additional bands at 120 and 205 kDa. Image processing after cLSM showed that anti-CD75 reactivity was significantly greater on E-cadherin-positive distal and collecting tubular cells from CaOx stone-forming kidneys, at a mean (sd) intensity of 87 (7), than on those from normal kidneys, at 41 (5) (P = 0.005). CONCLUSION: CD75 expression in human kidney was primarily on the luminal surface of distal tubules and collecting ducts. Whether increased epithelial CD75 expression in CaOx stone disease is a cause or result of the disease remains to be clarified.

Cell-surface matrix proteins and sialic acids in cell-crystal adhesion; the effect of crystal binding on the viability of human CAKI-1 renal epithelial cells.

OBJECTIVE: To investigate the role of sialic acids and cellular matrix proteins as crystal-binding molecules in human calcium-oxalate nephrolithiasis. MATERIALS AND METHODS: The well-defined human renal cancer cell line CAKI-1 was used a standard cell culture system. After enzymatic digestion of various cell surface molecules, the binding of alpha2,6 (Sambucus nigra, SN-) and alpha2,3 (Maackia amurensis, MA)-specific lectins to CAKI-1 cells was analysed. Simultaneously, the effect on adhesion and release of calcium oxalate monohydrate crystals was investigated (eight replicates). The effect of crystal adhesion on cell viability was assessed using Trypan blue exclusion (five replicates). RESULTS: Neuraminidase decreased MA-lectin binding of CAKI-1 cells by 39% (P < 0.05) but elevated SN-lectin binding by 812% (P < 0.05). Simultaneously, crystal binding to CAKI-1 cells was increased by 28% (P > 0.05). Pretreatment with collagenase type I, trypsin and dispase II reduced crystal-binding by 61-74% (P < 0.05) with no effect on sialic acid-specific lectin-binding. However, only collagenase type I and dispase (ratio 4 : 1) were also able to release crystals from their receptor-binding sites (P < 0.05). An increase in the number of cell surface-bound crystals correlated significantly with a decrease in cell viability (P < 0.05). CONCLUSIONS: alpha2,3-linked sialic acids protect cells from crystal-binding. Much greater SN-lectin binding associated with only moderately increased crystal binding argues against alpha2,6-linked sialic acids as a main target structure of crystals. In contrast, collagen type I, type IV and/or fibronectin seem to be potent crystal-binding molecules on human renal epithelial cells, with collagen type I involved in a potential second step of crystal-cell interaction.

Loss of CD38 correlates with simultaneous up-regulation of human leukocyte antigen-DR in benign prostatic glands, but not in fetal or androgen-ablated glands, and is strongly related to gland atrophy.

OBJECTIVE: To determine whether CD38 loss in benign and malignant prostatic disease is related to human leukocyte antigen (HLA)-DR up-regulation, by assessing the histopathology of the prostate and the effect of androgen deprivation. MATERIALS AND METHODS: Serial sections of frozen fetal (eight), infant (six), normal adult (10), benign hyperplastic (BPH, 24), and primary (10) and hormone-treated (11) carcinomatous human prostatic tissues were analysed by immunohistology for anti-CD38 and HLA-DR antigens. RESULTS: In BPH samples there was a significant correlation between CD38 loss (mean 21% of acini) and HLA-DR up-regulation (mean 20%; P < 0.001). Moreover, 76% of all CD38-negative acini in BPH had HLA-DR up-regulation in the same prostate epithelial cells, predominantly in atrophic and cystic glands, and in cells with retained secretions (74%). In contrast to the uniform expression in normal adult prostate, CD38 was negative or partly expressed in fetal acini (mean 19%) and almost completely negative in acini of the early infant period (mean 0.7%). In contrast to BPH, cancer cells did not selectively up-regulate HLA-DR when CD38 was lost. In patients with cancer treated by androgen deprivation, cancer cells were CD38-negative. CONCLUSIONS: The absence of CD38 and presence of HLA-DR expression in prostatic epithelium is consistent in BPH and tissue surrounding tumour, and strongly related to gland atrophy. This is particularly interesting as HLA-DR triggering can induce apoptosis of cells, whereas CD38 prevents it. A permissive role for androgens to maintain full CD38 expression in epithelial cells is suggested.

Differential expression of interleukin-15, a pro-inflammatory cytokine and T-cell growth factor, and its receptor in human prostate.

BACKGROUND: Pro-inflammatory interleukin (IL)-15 plays a major role in host defense and chronic inflammation by stimulating T-lymphocyte recruitment and growth. Expression of IL-15 and IL-15 receptor (IL-15R) in human prostate was examined. METHODS: Normal and benign hyperplastic (BPH) prostate specimens (n = 23) were analyzed for IL-15 and IL-15Ralpha-chain expression by immunohistochemistry and Real-Time-PCR/RT-PCR. Regulation of prostatic stromal cell (PSC) IL-15 mRNA and effect of IL-15 on prostatic cell growth were analysed in vitro. RESULTS: In normal prostate, anti-IL-15 and anti-IL-15Ralpha-chain reactivity were restricted to smooth muscle and stromal cells. However, in BPH, in addition epithelial cells frequently exhibited discrete anti-IL-15R and often intense, membranous anti-IL-15 reactivity. IL-15/IL-15R mRNA were detected in all prostatic cells types. In BPH tissues, IL-15 mRNA content was variable (15-fold). IL-15 mRNA synthesis of PSC was significantly up-regulated by IFN-gamma. Furthermore IL-15 strongly stimulated the growth of BPH-T-lymphocytes and weakly that of carcinoma cell lines, but not of stromal cells. CONCLUSIONS: Overexpression of IL-15 and IL-15Ralpha-chain in BPH and massive proliferation of BPH-T-lymphocytes induced by IL-15 suggest a role for IL-15 in prostatic inflammation. Since IFN-gamma, a T-lymphocyte product, stimulates prostatic IL-15 production; chronic inflammation might be triggered by this paracrine loop.

Human accessory cells activate fresh, normal, tumor-distant T lymphocytes but not tumor-infiltrating T lymphocytes to lyse autologous tumor cells in a primary cytotoxic T lymphocyte assay in renal cell carcinoma.

OBJECTIVES: Search for an ideal responder T-lymphocyte source for adoptive T-lymphocyte therapy in renal cell carcinoma (RCC). METHODS: Cytotoxic T-lymphocyte (CTL) activity of (a) normal, tumor-distant, renal T lymphocytes, (b) tumor-infiltrating T lymphocytes and (c) peripheral blood T lymphocytes against autologous tumor epithelial cells (EC) of 10 patients with organ-confined, primary RCC was analyzed in a primary CTL assay. Freshly enriched T lymphocytes were cultured with or without autologous, mitomycin-C-treated normal or tumor EC in the presence or absence of antigen-presenting cells (APC) for 7 days. RESULTS: Both tissue T-lymphocyte populations displayed a similar CD4:CD8 ratio (1:1). Elevated CD62L coexpression of CD4+ T lymphocytes in normal, tumor-distant, renal tissue resulted in a significantly higher transient T-cell activation than that seen in renal tumor tissue (46 vs. 27%; p = 0.002). All trials to induce significant lysis of autologous, renal tumor EC in tumor-infiltrating and peripheral blood T lymphocytes failed. Only when normal, tumor-distant, renal T lymphocytes were stimulated by autologous APC and tumor EC was significant autologous tumor EC lysis obtained (mean 14%; p<0.05). Costimulation by anti-CD3 (mean 21%; p<0.05) or interleukin-2 (mean 31%; p<0.05) further increased tumor EC lysis significantly. CONCLUSIONS: Increased turnover of T lymphocytes in normal, tumor-distant, renal tissue was associated with a higher yield of pre-CTL which can be transformed into a functionally active effector T-cell pool by stimulation via antigen plus APC. Thus, tumor-distant renal tissue has to be included in the tissue-sampling procedure for adoptive immunotherapy.

Local intratumoral tumor necrosis factor-alpha and systemic IFN-alpha 2b in patients with locally advanced prostate cancer.

To examine tolerability and activity of local, intratumoral tumor necrosis factor-alpha (TNF-alpha) and systemic interferon-alpha2b (IFN-alpha2b) in locally advanced, hormone-resistant prostate cancer (LA-HRPC), 10 patients with LA-HRPC (T4N x M0, n = 3, T4N x M1, n = 5; T4N1M1, n = 2) were treated with recombinant TNF-alpha injected locally into prostate tumor tissue at 4-week intervals (maximum of four cycles) combined with intermittent subcutaneous (s.c.) administration of 5 x 10(6) IU IFN-alpha2b. Twenty-nine TNF-alpha cycles were administered. Despite significant TNF-alpha leakage into the systemic circulation 2 h after intraprostatic application (from a mean of 9 to a mean of 416 pg/ml; p = 0.0034), TNF-alpha (and IFN-alpha2b) was well tolerated (WHO grade 1-2 toxicity), possibly because of its rapid neutralization by increasing soluble 55-kDa and 75-kDa TNF receptor levels in the serum (mean increase 268% and 91%, respectively) at the same time. TNF-alpha induced prostate tumor cell necrosis in all patients, leading to a significant reduction of prostate volume in 9 of 10 cases (mean 38%; p = 0.0025). The significant short-term increase of prostate-specific antigen (PSA) (mean 65%; p < 0.001), tissue polypeptide-specific antigen (TPS) (mean 85%; p = 0.001), and possibly interleukin-8 (IL-8) (mean 2687%; p < 0.009) serum levels within 4 h after TNF-alpha confirmed the cytotoxic effect in vivo. In the long term, serum PSA levels dropped by 18%-87%, reaching the nadir value 7 weeks after baseline. Objective responses of metastases were not seen. Intraprostatic administration of TNF-alpha is feasible at a tolerable toxicity in patients with LA-HRPC and, thus, may be a new treatment option for these patients.

Angiogenesis stimulation in explanted hearts from patients pre-treated with intravenous prostaglandin E(1).

BACKGROUND: Prostaglandin E(1) (PGE(1)) is a potent vasodilator and induces angiogenesis in animal tissues. Previous clinical studies demonstrated that PGE(1) improves hemodynamic parameters in patients with heart failure listed for heart transplantation (HTX). Therefore, we designed a retrospective immunohistochemistry study to investigate various markers of angiogenesis using hearts explanted from PGE(1)-treated patients with idiopathic dilated cardiomyopathy (IDCM). METHODS AND RESULTS: We investigated neovascularization in 18 hearts explanted from patients with IDCM: 9 patients received treatment with chronic infusions of PGE(1) for end-stage heart failure before HTX, whereas the remaining patients with IDCM did not receive PGE(1) and served as controls. We used immunoreactivity against CD34, von Willebrand factor (vWf), vascular endothelial growth factor (VEGF), and MIB-1 (Ki-67) to quantify angiogenesis, and used sirius red staining to determine the degree of fibrosis. Compared with the control group, PGE(1)-treated patients had significantly more CD34-, vWf- and MIB-1-positive cells in the sub-endocardium, myocardium and sub-epicardium (p < 0.01). The degree of fibrosis in the hearts of PGE(1)-treated patients was significantly lower than in control patients (p < 0.05), but we did not see any difference in the percentage of muscle mass. Finally, throughout the ventricles, we found significantly more VEGF-positive capillaries in the PGE(1) group (p < 0.0001). CONCLUSIONS: The data suggest that PGE(1) could be a potent inducer of angiogenesis and the angiogenic factor VEGF, and could cause reduced fibrosis in the failing human heart.

Vascular endothelial growth factor receptor 2 (VEGFR2) expression in squamous cell carcinomas of the head and neck.

OBJECTIVES: Vascular endothelial growth factor receptor 2 (VEGFR2; Flk-1 [fetal liver kinase]/KDR [kinase insert domain containing receptor]) has been identified as a high affinity receptor for vascular endothelial growth factor (VEGF) on vascular endothelium. Head and neck squamous cell carcinomas (HNSCC) have already been shown to produce substantial amounts of VEGF. VEGFR2 is supposed to play a major role in tumor-neoangiogenesis. METHODS: We investigated 24 tumor specimens and 4 HNSCC cultured tumor cell lines for the incidence and distribution of VEGFR2 by immunohistochemistry using monoclonal antibodies (mAbs) and RT-PCR. RESULTS: Analysis of frozen sections by immunohistochemistry showed that in 90% of tumor specimens VEGFR2-positive cells were found which were associated with vascular endothelium. VEGFR2 was also expressed on tumor cells and vessels, which was confirmed by double immunolabeling of tumor cells with an a-cytokeratin mAb. Furthermore, 2 (JPPA, SCC9) of 4 HNSCC cultured tumor cell lines revealed positive VEGFR2 immunoreactivity. Synthesis of VEGFR2 mRNA on all 4 HNSCC cultured tumor cell lines (JPPA, SCC9, SCC25, and LFFR) and in 6 tumor specimens was confirmed by RT-PCR. In conclusion, our results showed that VEGFR2 is expressed in HNSCCs on tumor cells. VEGFR2 expression is associated with the beginning of vasculogenesis represented by accumulation of VEGFR2-positive cells budding into new vessels ("hot spots"). The focal expression pattern of VEGFR2 on tumor cells suggests an autocrine loop for VEGF in tumor cell growth.

Expression of the VEGF-receptor Flt-1 in benign, premalignant and malignant prostate tissues.

PURPOSE: Vascular endothelial growth factor (VEGF) is one of the most potent regulators of angiogenesis and has been shown to act upon two tyrosine kinase family receptors: c-fms-like tyrosine kinase (Flt-1) and fetal liver kinase. Preliminary reports have emphasized that expression of VEGF receptors is endothelial cell-specific. In this study we verified the localization and distribution of Flt-1 protein and mRNA expression in prostatic adenocarcinoma (CaP) as well as prostate intraepithelial neoplasia (PIN) and benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: 30 selected surgical specimens exhibiting areas with CaP, PIN and BPH histology were evaluated for Flt-1 protein expression by immunohistochemistry. Results were compared with tumor differentiation (Gleason-Score), serum-PSA and clinical followup. Flt-1 synthesis by prostatic carcinoma cell lines, freshly isolated BPH epithelial cells (BPH-EC) and stromal cells was investigated using RT-PCR and intron spanning primer. RESULTS: VEGF receptor Flt-1 specific anti-sera revealed significant staining of prostatic endothelial cells, but the reactivity was not restricted to endothelial cells. BPH-epithelial cells of all specimens reacted significantly with anti-Flt-1. In contrast, tumor cells failed to react with anti-Flt-1 in 56% of the specimens. BPH-EC revealed a uniform anti-Flt-1 reactivity, which was less pronounced and weaker in PIN. Loss of anti-Flt-1 reactivity of prostatic tumor cells did not correlate with preoperative PSA serum levels but increased with tumor dedifferentiation. Interestingly, tumor cells of all CaP specimens with a Gleason score of >8 exhibit no anti-Flt-1 immunoreactivity. Accordingly while PC3, DU145 and LNCaP cells were negative when tested using RT-PCR all BPH tissue derived BPH-EC revealed Flt-1 coding mRNA expression. CONCLUSIONS: Widespread distribution of VEGF receptor Flt-1 in BPH, PIN and prostate cancer specimens suggests that VEGF function in prostate is not restricted to endothelial cells and angiogenesis. However, since the receptor is lost in CaP cells and with tumor dedifferentiation, these yet unknown effects of VEGF on epithelial cells are obviously suppressed with malignant transformation.

Automated data acquisition by confocal laser scanning microscopy and image analysis of triple stained immunofluorescent leukocytes in tissue.

The aim of the study was to develop a novel system permitting automated analysis of multicolor immunofluorescence-staining of cells in solid tissues which would be comparable to the analytical capacity of flow cytometry. In the user friendly automated data acquisition and image processing system which was established, the software includes a set of pre-defined processing steps for improved object identification and can be either interactive or fully automatic. As with multi color flow cytometry, stained cells can be analyzed in a fully automated manner regardless of tissue type. The software organizes computerized sample movement, autofocus, laser readjustment, data capture and storage as well as calculation. Data are presented as histograms indicating the staining intensity and frequency of each antigen, and in dotplots with each channel plotted against the other. The calculated statistics give information about how many of the cells are single-, double- or triple-reactive and how intensely they react with the respective antibodies. Comparison of data generated by this automated fluorescence confocal laser scanning microscopy (AF-CLSM) with flow cytometry using triple stained peripheral blood lymphocytes revealed a highly significant correlation between the methods (P<0.001). A correlation was also observed when sections triple stained for anti-CD45, -CD3 and -CD8 were analyzed by AF-CLSM and the data were compared to visual/manual cell counting (P<0.01). The AF-CLSM system permits for the first time, fast (online) and reproducible analysis of immunofluorescence staining of an unlimited number of cells in tissue sections. The software, including a manual, is available for a small fee to cover the costs of printing and postage.

Role of bacteria in the development of kidney stones.

Currently, only struvite stones are regarded as deriving from bacteria. Recent work has suggested that calcium-based stones might also have an infectious origin. Nanobacteria, small intracellular bacteria found in human kidney stones, are capable of forming a calcium phosphate shell, and thus could serve as crystallization centres for renal calculi formation. Until now, however, all trials performed to confirm the presence of nanobacteria in human calculi, serum or urine have failed. In a hyperoxaluric rat model, tissue-residing macrophages were able to remove interstitial crystals and thus may not be primarily engaged in defending against micro-organisms, if present.

MHC-class-I expression in human breast cancer correlates with nuclear localization of the 90 kDa heat-shock-protein.

Breast cancer cells frequently exhibit a reduction in expression of major-histocompatibility-complex (MHC) class I proteins which blocks cytotoxic T-lymphocyte (CTL) mediated apoptosis. Recent studies indicate that the 90 kD heat-shock-protein (HSP90) plays a major role in the transfer of antigenic peptides to the MHC class I complex. HSP90 is a molecular chaperone which is involved in signal transduction and regulation of apoptosis. Since HSP90 is described to be elevated in breast cancer, its relationship with MHC class I expression was investigated. Using immunohistochemistry we analyzed the expression and localization of HSP90 and MHC class I in 17 human breast tumors. Positive correlation (p < 0.025) between strong nuclear staining for HSP90 and high MHC class I expression was observed. In tumors with reduced MHC class I expression, no nuclear localization of HSP90 was detectable. These findings lead to the hypothesis that tumor cells with high MHC class I expression and susceptibility to CTL action may escape apoptosis by a mechanism which involves increased nuclear HSP90.

Regulation of heat shock protein 27 expression of prostatic cells in response to heat treatment.

BACKGROUND: The clinical value of heat-induced coagulation of prostatic tissue is evaluated as a minimally invasive treatment for patients with benign prostatic hyperplasia (BPH) and, more recently, localized prostate cancer (PC). To obtain a more detailed insight on the effect of heat on prostatic cells, heat shock protein (HSP) 27 expression of normal and malignant prostatic cells was studied. METHODS: In vitro, HSP27 expression of prostatic stromal cells and the human prostate cancer cell line LNCaP was studied by Western blotting when cultured at 37 degrees C. Subsequently, the effect of a sublethal heat shock from 43-49 degrees C for 60 min on HSP27 expression of LNCaP was determined. In vivo, HSP27 expression pattern of nine human prostates, which were treated in vivo by thermoablation with transrectal high-intensity focused ultrasound (HIFU) 3 hr-8 days prior to surgical removal, was analyzed by immunohistochemistry. Untreated BPH (n = 10) and PC (n = 7) specimens served as controls. RESULTS: Under physiologic conditions (37 degrees C), LNCaP and prostatic stromal cells expressed a 27-kD and 56-kD anti-HSP27 reactive molecule. Following sublethal cell heating, HSP27 (27 kD) expression of LNCaP increased by 3-4-fold in a temperature-dependent manner. In untreated BPH specimens (n = 10), muscle cells stained HSP27-positive in all samples, while epithelial cells (EC) were negative in 6 out of 10 specimens. At the border of the high-intensity focused ultrasound (HIFU) necrosis, increased HSP27 expression was consistently demonstrable (n = 9). HSP27 upregulation was strongest 2-3 hr after HIFU but still demonstrable after 5-8 days. In this border zone, basal and secretory EC as well as muscle cells stained strongly for HSP27. CONCLUSIONS: Benign and malignant human prostatic cells respond to heat by increased expression of HSP27 in vitro and in vivo. Transrectal HIFU therapy induces intraprostatic thermonecrosis surrounded by a zone characterized by a massive upregulation of HSP27 expression.

Serial tissue polypeptide specific antigen determination in the followup of hormone treated carcinoma of the prostate.

PURPOSE: We determined the impact of serum cytokeratin-18-related tissue polypeptide specific antigen (TPS) in monitoring hormone treated carcinoma of the prostate. MATERIALS AND METHODS: From 1991 to 1996, serial TPS and prostate specific antigen (PSA) determinations (3,882) in 443 hormone treated prostate carcinoma patients were correlated with the clinical course for a mean of 22 months. RESULTS: Elevated TPS levels were significantly associated with disease progression in hormone treated stage M1 carcinoma of the prostate (p = 0.001), even in high grade, PSA negative tumors. Post-therapy TPS declines following second line therapy in hormone refractory prostate cancer patients (92) correlated significantly with subjective response (p = 0.001, PSA p = 0.02) and progression-free survival time (r(s) = -0.76, PSA r(s) = -0.32). A TPS decrease of more than 50% coincided with palliation in 90% of patients (PSA 64%) and predicted the best chance of a longer progression of free survival (p < 0.00005, PSA p = 0.036). Vice versa, rising TPS levels (more than 20%) coincided with subjective response in only 1 of 37 patients (PSA 9 of 33). CONCLUSIONS: TPS may be a useful adjunct to PSA in monitoring hormone refractory, metastasized prostate cancer.

Microfilarial clearance in loiasis involves elevation of Th1 and Th2 products and emergence of a specific pattern of T-cell populations.

Diethylcarbamazine (DEC) induced clearance of microfilaraemia in loiasis is associated with severe posttreatment reactions. To define the switch from hypo- to hyper-responsiveness associated with DEC treatment, phenotypic alterations of T-lymphocytes, characterized by flow cytometry, and cytokines, determined by enzyme linked immunosorbent assay, were monitored in a microfilaraemic patient. In contrast to reports on onchocerciasis and lymphatic filariases, no elevation of interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha was observed. The most severe side effects coincided with an elevation of interferon (IFN)-gamma on day 3, followed by IL-10, transforming growth factor (TGF)-beta 2 and macrophage inflammatory protein-1 alpha (MIP-1 alpha) peaking on day 5. Phenotypically, T-cell activation markers CD38, CD54 and CD25 were significantly expressed before treatment, with high CD38 expression still existing one year after clearance of microfilaraemia. Treatment-related increases were observed with anti-CD122, anti-HLA-DR and anti-CD69. CD28 was expressed before treatment on almost 100% of CD4+ and CD8+ T cells and dropped to 20% by day 5, reaching again baseline levels on day 21. Furthermore, there emerged 20% TCR alpha beta+/CD3+ T cells and 10% anti-beta V5(c)+ T cells, altogether indicating a specific pattern of T-helper (Th) 1 and Th2 cytokines as well as expansion of certain pauciclonal T-cell populations in response to microfilarial clearance.

Phenotypic characterization of infiltrating leukocytes in benign prostatic hyperplasia.

This study for the first time elaborates on cells of the immune system present in benign prostatic hyperplasia (BPH). Compared with normal prostate, all BPH-derived specimens revealed a marked increase of CD45+ leukocytes, characterization of which demonstrated three major cell types, i.e., CD3+ T lymphocytes, CD11c+ macrophages and CD20+ B lymphocytes. Frequencies of CD3+ cells/mm2 of cryocut sections were increased at least 10 times in BPH specimens, and the CD8+:CD4+ T suppressor/cytotoxic:T helper cell ratio was reversed. The infiltrating leukocytes predominantly populate the interstitium and accumulate around epithelial ducts which, however, were found to be invaded and/or destroyed only in a number of cases. Phenotypic alterations of surface antigen expression on prostate epithelial cells in BPH that might be due to the presence of lymphocytes were examined by using monoclonal antibodies (mAb) directed against human leukocyte antigens (HLA). Whereas anti-HLA-DR reactivity in normal prostate is restricted to small numbers of macrophages and includes neither prostate epithelial cells nor prostate T cells, it was found to be dramatically increased in BPH, comprising CD45+ cells and prostate epithelial cells as demonstrated by double-staining with anti-cytokeratin or anti-prostate-specific antigen. A mean of 40% of analyzed epithelial glands in BPH reacted with anti-HLA-DR, but not with anti-DQ or -DP monoclonal antibodies. A new method for the enrichment of prostate-derived lymphocytes was established to facilitate phenotypic analysis by flow cytometry, demonstrating 70 to 80% of enriched CD45+ cells to stain for CD3, approximately 60% thereof for CD4, 30% for CD8, and the remaining 10% with anti-CD20, a pan-B-cell marker. Flow cytometry showed that, in contrast to peripheral T cells, both CD4+ and CD8+ prostatic T cells were positive for the T cell activation markers HLA-DR and interleukin-2-receptor.

Lipofibroma of the median nerve: a report of two cases.

Two cases of lipofibroma of the median nerve are described. The literature is reviewed and the clinical and treatment aspects of this unusual condition are discussed.