Biomedical subjects

T Koji

Publications and source records attributed to T Koji.

At least 73 records · Page 4Linked to original sources

PubMed1998

Activation of bullous pemphigoid antigen gene in mouse ear epidermis by ultraviolet radiation.

Bullous pemphigoid (BP) is an autoimmune blistering disease and is a photoaggravated dermatosis, but the mechanism of the aggravation is still unknown. Since damage to DNA initiates transcription of some genes, we investigated in epidermis of mouse ears the relationship between DNA damage by ultraviolet (UV) radiation and BP antigen (BP-Ag) gene activation. For this, albino male mice were irradiated with 254 nm wavelength UV for a total dose of 500 J m-2. At fixed times (0.5, 2, 24, 48 and 72 h) post-UV irradiation, mouse ears were cut off, frozen and sectioned. In the sections, it was found that immunohistochemically detectable pyrimidine dimers were observed in nuclei of all epidermal cells at 0.5 h that were almost repaired by 72 h; a frequency of single strand breaks in DNA detected by in situ nick translation started to increase in nuclei of all epidermal cell layers at 0.5 h and the increase continued up to 24 h; mRNA for BP-Ag localized by non-radioactive in situ hybridization appeared in nuclei of basal cells at 0.5 h and in both nuclei and cytoplasm at 2 h; and immunoreactive BP-Ag started to increase in the basal cell cytoplasm and in the basement membrane zone at 2 h. BP-Ag started to accumulate in the basement membrane zone at 2 h. It is suggested that UV radiation increased BP-Ag synthesis through BP-Ag synthesis through BP-Ag gene activation and that this reaction is a factor which aggravates BP following UV irradiation in BP patients.

Animals↗

PubMed1998

Differential expression of IFN-gamma, IL-4, IL-10, and IL-1beta mRNAs in decalcified tissue sections of mouse lipopolysaccharide-induced periodontitis mandibles assessed by in situ hybridization.

To examine the role of T cell subgroups, Th1 and Th2, in the development of periodontitis, the expression of various cytokines was investigated in a mouse model of alveolar bone resorption using in situ hybridization (ISH) with digoxigenin-labeled oligonucleotides. When mice received repetitive injections with Escherichia coli lipopolysaccharide into the gingiva every 48 h, alveolar bone resorption was detectable after the fourth injection, reaching a maximum after the 13th injection. For the best performance of ISH, we first had to choose a decalcification protocol. Among various decalcification protocols, 10% EDTA (4 degrees C, 5-6 days) was the best for 28S rRNA staining. Positive cells for transcripts of interferon-gamma (Th1 product) were detected after the fourth injection, reaching a maximum after the tenth injection. A similar pattern was obtained for interleukin (IL)-10 mRNA (Th2 product) and IL-1beta, while the positive cell number reached a maximum after the 13th and 10th injections, respectively. The number of IL-4 mRNA (Th2 product)-positive cells remained low till the tenth injection, but increased thereafter. Consequently, we found that the population change from Th1 to Th2 in the inflammation site correlated with the transition from gingivitis to periodontitis, indicating differential roles of T cell subgroups in the development of periodontitis.

Alveolar Bone Loss↗

PubMed1998

Expression and function of Fas and Fas ligand on peripheral blood lymphocytes in normal subjects.

We investigated the expression and function of Fas and Fas ligand (FasL) on peripheral blood lymphocytes (PBLs). The cells were stimulated with various cytokines or 12-0-tetradecanoyl phorbol 13-acetate (PMA) plus ionomycin. About 30% of unstimulated PBLs expressed Fas, and the expression was augmented by interleukin-1beta (IL-1beta), IL-2, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), or PMA plus ionomycin. Although only minimal FasL expression was detected on unstimulated PBLs, FasL expression was markedly induced by IL-2 or PMA plus ionomycin, suggesting that Fas and FasL were both expressed on IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs. Although IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs were positive for both Fas and FasL, no significant increase in apoptosis was demonstrated in these activated PBLs. In addition, treatment of PBLs with IL-2 or PMA plus ionomycin did not change anti-Fas-induced apoptosis, although these activated PBLs expressed Fas strongly when compared with unstimulated PBLs. Only IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs killed Fas+ target cells efficiently via the interaction of Fas on target cells with FasL of PBLs. Bcl-2 was constitutively expressed on unstimulated PBLs, but its expression was significantly augmented by IL-2 or PMA plus ionomycin. The expression of Bax was clearly induced only on IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs and that of other Bcl-2 family proteins such as Bcl-x and Bad could not be detected on human PBLs, including IL-2-stimulated or PMA-plus-ionomycin-stimulated PBLs. Our results suggest that PBLs activated by IL-2 or PMA plus ionomycin express both Fas and FasL and that they kill Fas+ target cells by using FasL on the surface. The resistance of these activated PBLs to Fas-mediated apoptosis may be due to the augmented Bcl-2 expression or the presence of Bcl-2:Bax heterodimers on these cells.

Adult↗

PubMed1998

Apoptosis induction in synovial fibroblasts by ceramide: in vitro and in vivo effects.

Several lipid second messengers are important mediators of extracellular signals. Among them ceramide, which is formed by cell membrane sphingomyelin, influences the apoptotic signal pathway through Fas antigen. We examined the apoptotic effect of cell-permeable C2-ceramide on rheumatoid synovial fibroblasts in vitro and in vivo. Exposure of cultured human rheumatoid synovial fibroblasts to C2-ceramide for 24 hours produced internucleosomal DNA fragmentation and morphologic changes characteristic of apoptosis. This C2-ceramide-mediated apoptosis was dose dependent as confirmed by analysis of cytosolic oligonucleosome-bound DNA of treated synovial fibroblasts. We also demonstrated that intra-articular administration of C2-ceramide into Fas-deficient MRL lpr/lpr mice produced a profound reduction of synovial hyperplasia within 24 hours. In situ nick end labeling analysis confirmed the induction of apoptosis in synovial lining cells. Our results indicate that C2-ceramide may function as a potent inducer of apoptosis in the synovium and suggest that pharmacologically-induced apoptosis may be useful as a new therapeutic modality for rheumatoid arthritis.

Animals↗

PubMed1998

Apoptosis in labial salivary glands from Sjögren's syndrome (SS) patients: comparison with human T lymphotropic virus-I (HTLV-I)-seronegative and -seropositive SS patients.

Apoptosis is a type of cell death that occurs during morphogenesis and development of the immune system. One of the mechanisms is mediated through the Fas and Fas ligand (FasL) pathway. To determine the possible involvement of Fas and its ligand in salivary gland destruction, we analysed the appearance of nuclei with DNA fragmentation by using nick end labelling (TUNEL) and the expression of Fas and FasL by immunohistochemistry in labial salivary glands. Furthermore, we compared the features of apoptosis in labial salivary glands between HTLV-I- and HTLV-I+ SS. When the frozen sections of 10 primary SS patients in the absence of anti-HTLV-I antibody were examined, several apoptotic cells were found in the acinar and ductal epithelial cells as well as infiltrated mononuclear cells. Both Fas and FasL were detected in the infiltrated mononuclear cells. Acinar epithelial cells, which are surrounded by FasL+ mononuclear cells, were also double-positive with Fas and FasL, although the expression of FasL was localized at their apical border, suggesting that apoptosis of mononuclear cells was achieved by activation-induced mechanisms through Fas/FasL pathways, and that of acinar epithelial cells was mediated by FasL derived from either acinar epithelial cells themselves or infiltrated mononuclear cells. Interestingly, Fas expression in ductal epithelial cells was localized around the lumen side of the ducts, indicating that FasL secreted from acinar epithelial cells may induce Fas-mediated apoptosis of ductal epithelial cells. We also studied the labial salivary glands from nine SS patients with anti-HTLV-I antibodies. There was no significant difference in the occurrence of apoptotic cells or in the expression of Fas and FasL between HTLV-I+ and HTLV-I- SS patients. It was of note that neither the expression of Fas and FasL nor the presence of apoptotic cells were determined in labial salivary glands from subjects without SS. These findings indicate that Fas-mediated apoptosis in salivary glands could be involved in the pathological manifestations of SS, irrespective of HTLV-I seropositivity.

Adult↗

PubMed1998

CD4+ T-cell-mediated cytotoxicity against staphylococcal enterotoxin B-pulsed synovial cells.

Apoptosis of synovial cells in rheumatoid arthritis (RA) synovium determined in vivo is suggested to counteract the overgrowth of synovium. Immunohistological examination has revealed the infiltration of activated CD4+ T cells, which express Fas ligand (FasL), in RA synovium. The presence of a putative antigen (Ag) of autoimmune disorders in a target organ may induce the activation of specific T cells in the inflammatory region such as RA synovium. We examined the possible role of CD4+ T cells activated by synovial cells in a staphylococcal enterotoxin B (SEB)-dependent manner, inducing synovial cell apoptosis. Synovial cells were cultured with or without interferon-gamma (IFN-gamma) and further incubated with CD4+ T cells in the presence of SEB. After the cocultivation, both the cytotoxicity and FasL expression of CD4+ T cells were investigated. Constitutive Fas expression was detected on both unstimulated and IFN-gamma-stimulated synovial cells. CD4+ T cells did not kill SEB-pulsed unstimulated synovial cells efficiently. In contrast, when CD4+ T cells were incubated with IFN-gamma-stimulated synovial cells with SEB whose human leucocyte antigen (HLA)-DR and -DQ expression was markedly induced, significant cytotoxicity by these cells against synovial cells was detected. The addition of anti-HLA-DR and -DQ monoclonal antibodies (mAbs) or human Fas chimeric protein (hFas-Fc) reduced this cytotoxicity. FasL expression of CD4+ T cells cocultured with IFN-gamma-stimulated synovial cells with SEB was significantly induced. Furthermore, the addition of mAbs against CD54, CD58 and CD106 inhibited both the cytotoxicity and FasL expression of CD4+ T cells induced by IFN-gamma-stimulated synovial cells in the presence of SEB, indicating the importance of costimulatory molecules on synovial cells in activating CD4+ T cells. Our results suggest that CD4+ T cells are activated by synovial cells by an SEB-dependent manner and express FasL, inducing Fas-mediated apoptosis of the latter cells. These phenomena may regulate the overgrowth of synovial cells in RA synovium.

Antibodies, Monoclonal↗

PubMed1998

Expression of endothelial and inducible nitric oxide synthase in human glomerulonephritis.

The presence of nitric oxide (NO) in the kidney has been implicated in the pathogenesis of human glomerulonephritis. However, the exact type of glomerular cells that express NO synthase (NOS) and the NOS isoform involved in the local production of NO has not been identified in the human diseased kidney. We examined the expression of three isoforms of NOS, inducible NOS (iNOS), endothelial NOS (eNOS) and brain NOS (bNOS) in the renal tissue of patients with IgA nephropathy (IgAN, N = 10), lupus nephritis (LN, N = 5), membranous nephropathy (MN, N = 5) and minimal change nephrotic syndrome (MCNS, N = 5). Sections were immunostained and the correlation between the expression of each NOS and the degree of glomerular injury in that section was also examined. Normal portions of surgically resected kidneys served as controls. eNOS was present in glomerular endothelial cells and endothelium of cortical vessels in the control and diseased kidneys. iNOS was localized in mesangial cells, glomerular epithelial cells and infiltrating cells in the diseased glomeruli, whereas immunostaining for iNOS was hardly detected in control kidneys. In addition, the expression pattern of eNOS in each glomerulus was the reverse of that of iNOS. In IgAN and LN, the extent of staining for eNOS correlated negatively with the degree of glomerular injury, while the extent of staining for iNOS correlated positively with the degree of glomerular injury in the same tissues. bNOS was not detected in normal or nephritic glomeruli. Our results indicate the presence of a NO pathway in human diseased kidney, and suggest that NO derived from eNOS and iNOS may be involved in the progression of renal diseases and that NO derived from each NOS may play an important role in different way in human inflamed glomeruli.

Adult↗

PubMed1998

Expression of decay accelerating factor mRNA and complement C3 mRNA in human diseased kidney.

BACKGROUND: Decay accelerating factor (DAF), a product of mesangial cells in vitro, is expressed on the surface of cells and is a candidate for the focal suppression of complement activation. It is not clear at present whether the levels of expression of DAF and intrarenal C3 synthesis correlate with the level of tissue injury. METHODS: Immunohistochemistry for DAF and C3 and nonradioactive in situ hybridization with digoxigenin-labeled oligonucleotide probe for DAF and C3 mRNA were performed in 22 tissue samples of kidneys from patients with IgA nephropathy (IgAN), 6 with membranous nephropathy (MN), 6 with lupus nephritis (LN), and five normal kidneys. RESULTS: In the normal kidney, DAF was confined to the juxtaglomerular apparatus and little or no C3 was detected; however, a few glomerular cells were positive for DAF mRNA but no C3 mRNA positive cells were detected. In diseased kidneys, DAF and C3 as well as their mRNAs were detected in mesangial cells, tubular cells and infiltrating cells. Glomerular epithelial cells and Bowman's capsule cells contained little or no DAF and C3 but were positive for their mRNAs. The mean percentages of mesangial cells positive for DAF and C3 mRNAs were 49.3 +/- 11.5% and 50.7 +/- 10.3% in IgAN, and 17.0 +/- 6.3% and 19.4 +/- 9.0% in MN, respectively. The percentage of mesangial cells positive for DAF and C3 mRNAs among intraglomerular cells correlated positively with the degree of mesangial proliferation and glomerular sclerosis in IgAN. In contrast, in LN the percentage of glomerular cells positive for DAF mRNA correlated negatively with the degree of glomerular injury, while the percentage of cells positive for C3 mRNA did not change with the progression of the disease. The ratio of C3 mRNA/DAF mRNA of glomerular cells correlated with the degree of glomerular injury in both IgAN and LN. In the tubulointerstitium, the percentage of cells expressing mRNA, and C3 mRNA/DAF mRNA radio correlated with the degree of tubular atrophy and interstitial broadening in both IgAN and LN. CONCLUSIONS: We conclude that DAF and C3 mRNAs are synthesized in human diseased kidneys, and that a balance between locally synthesized DAF and C3 may be important in the progression of glomerulonephritis.

Adult↗

PubMed1998

Expression of vascular endothelial growth factor and its receptors in rats with protein-overload nephrosis.

BACKGROUND: Based on the fact that vascular endothelial growth factor (VEGF) increases vascular permeability, it is speculated that VEGF might be involved in the development of proteinuria, although this remains unconfirmed. The production and site of action of VEGF remains unclear in nephrotic renal diseases. METHODS: Non-radioactive in situ hybridization was performed to examine the expression of VEGF mRNA and its receptors, flt-1 and KDR/flk-1, in a rat model of nephrosis induced by intraperitoneal injection of bovine serum albumin (BSA). Saline injected rats were served as control animals. RESULTS: Neither morphological changes nor deposition of immunoglobulin or complement were observed in our model. Proteinuria developed, reaching a maximum level in rats injected with BSA for 3 days, followed by persistent proteinuria until day 14. The expression of mRNA for VEGF and the two receptors was markedly upregulated in glomeruli of BSA-induced nephritis compared with the control group. VEGF mRNA was localized in glomerular cells, including cells in mesangium, visceral and parietal epithelial cells. In contrast, flt-1 mRNA and KDR/flk-1 mRNA were expressed on glomerular endothelial cells and cells in mesangium. The ratio of glomerular cells positive for VEGF mRNA and its receptors mRNA increased proportionately with the severity of proteinuria. Immunohistochemistry for ED-1 and proliferating cell nuclear antigen showed no significant increase in infiltrating macrophage or cellular proliferation. CONCLUSIONS: Our results suggest that altered glomerular expression of VEGF and its receptors is not associated with proliferation of endothelial cells, but rather with proteinuria in BSA-induced nephritis in rats. VEGF may play a different role in different renal diseases.

Animals↗

PubMed1998

Autonomous cell death of mouse male germ cells during fetal and postnatal period.

Germ cell degeneration is common in mammalian testes during the developmental as well as the adult period. To investigate the extent and mechanisms of male germ cell death during fetal and neonatal life, the testes of mice at various fetal and postnatal ages extending from 13 days of gestation to 7 wk after birth were examined by electron microscopy and/or terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Electron microscopy revealed that the number of cells with typical features of spermatogenic cell apoptosis was highest at 13 days of gestation, coinciding with the time of immigration of primordial germ cells into gonads. A second peak was observed around 10-13 days after birth when the first wave of spermatogenesis had started and active spermatogonial proliferation was present. Surprisingly, we found a significant number of dying cells around birth, which exhibited morphological features of necrotic death. In agreement with the results of electron microscopy, TUNEL staining revealed that the dying germ cells present around birth were TUNEL negative, while positive nuclei were abundant in the lumen of seminiferous tubules of testes of 10- to 13-day-old mice. To investigate the mechanisms of induction of germ cell death, we examined the expression of Fas antigen immunohistochemically using rabbit antiserum raised against synthetic peptides for part of mouse Fas antigen. We found that among various developmental stages investigated, positive immunostaining for Fas antigen was present between 17 days of gestation and 1 day after birth, with the most intensive staining occurring on 17 days of gestation. Therefore, Fas-induced pathways may be implicated in embryonic male germ cell death, not prepubertal spermatogenic cell death.

Animals↗

PubMed1998

Role of apoptosis of thyrocytes in a rat model of goiter. A possible involvement of Fas system.

Apoptosis, a physiological process of cell death, may modulate the mass of the thyroid gland. We investigated the role of apoptosis and the possible involvement of Fas/Fas ligand (FasL) system in apoptosis during goiter formation and involution in a rat model of goiter. Rats were fed a low iodine diet and a goitrogen, 6-propyl-2-thiouracil, to induce goiter. Rats with goiter were then fed a high iodine diet to study the phase of involution. We examined the presence of apoptosis by electron microscopy (EM) and terminal deoxy-UTP nick end labeling (TUNEL). We also investigated the association between Fas and FasL expression and thyrocyte apoptosis using immunohistochemistry and Western blotting. To evaluate the proliferation of thyrocytes, proliferating cell nuclear antigen was examined immunohistochemically. The number of apoptotic cells increased during goiter formation and the early stage of involution, which were also associated with increased number of Fas-positive thyrocytes, and some of these cells contained TUNEL-positive nuclei. However, the expression of FasL was almost constant throughout the experiment. Proliferating cell nuclear antigen/TUNEL ratio markedly increased during goiter formation but decreased particularly during the late stage of goiter involution. Our results indicate that apoptosis of thyrocytes is a main factor of cell loss during goiter formation and involution and suggest that the Fas/FasL system is involved in the induction of apoptosis of these cells. Moreover, the delicate balance between apoptosis and cell proliferation may play an important role in the control of thyroid gland mass.

Animals↗

PubMed1998

Evidence for an inverse relationship between apoptosis and inducible nitric oxide synthase expression in rat granulosa cells: a possible role of nitric oxide in ovarian follicle atresia.

Ovarian follicle atresia is thought to be induced through apoptosis of granulosa cells. This study was designed to investigate the possible involvement of nitric oxide (NO) in granulosa cell apoptosis. In immature rat ovaries obtained 48 h after pregnant mare serum gonadotropin administration, immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), a method to detect apoptotic cells, revealed that inducible NO synthase (iNOS) was predominantly localized in granulosa cells in most healthy immature follicles with TUNEL-negative granulosa cells. In contrast, all atretic follicles with TUNEL-positive granulosa cells were iNOS-negative whatever the developmental stage of the follicle. In cultured granulosa cells, the addition of S-nitroso-N-acetyl-DL-penicillamine (SNAP), an NO generator, directly inhibited spontaneously occurring apoptosis. These results suggest that NO produced by iNOS in granulosa cells of immature follicles may prevent ovarian follicle atresia by inhibiting granulosa cell apoptosis in an autocrine/paracrine manner.

Animals↗

PubMed1998

Induction of apoptosis in ischemia-reperfusion model of mouse kidney: possible involvement of Fas.

Although ischemia-reperfusion of mouse kidney is known to cause severe renal failure due to tubular cell death, the exact cellular mechanism responsible for this phenomenon is not clear. To investigate the spatial and temporal development of renal cell death and the role of Fas/APO-1/CD95 (Fas) in this process, the left renal vessels were occluded in a group of mice for 30, 60, or 120 min followed by reperfusion for 24 h (n = 4 for each group). Analysis of the isolated DNA in agarose-gel electrophoresis revealed a typical ladder pattern of bands consisting of multiples of 180 to 200 bp, considered the hallmark of apoptosis. The intensity of the bands increased proportionately with the duration of ischemia. Histochemical analysis using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling showed the presence of nuclei with DNA double-strand breaks specifically in distal renal tubules of the outer medulla. The presence of apoptosis was also confirmed by electron microscopy. Analysis of total RNA by Northern blotting revealed one appropriate-sized band for Fas mRNA in the normal kidney, which intensified in the ischemia-reperfused kidney. Moreover, nonradioactive in situ hybridization revealed that distal renal tubular epithelial cells were positive for Fas mRNA in the outer medulla. Fas antigen was also localized to the renal tubular epithelial cells of the outer medulla by immunohistochemistry. The number of apoptotic cells in the ischemia-reperfusion kidney of the lpr/lpr mouse was low. These findings strongly indicate that ischemia-reperfusion of the kidney induces apoptosis of a specific area of tubular epithelial cells in the outer medulla through the Fas system.

Animals↗

PubMed1998

[Detection of receptor mRNAs using nonradioactive in situ hybridization].

To understand better the regulatory mechanism of cell function through bioactive substance such as hormones and cytokines, analysis of the gene expression of their receptors at the individual cell level is required. Since the presence of specific mRNA is a good index of gene expression, in situ hybridization (ISH) has been recognized as a powerful tool. Especially, nonradioactive ISH with synthetic oligodeoxynucleotide probe is a safe, quick and highly sensitive method. We have developed a unique method with thymine-thymine (T-T) dimer as a nonradioactive labeling, in which adjacent thymines are dimerized by ultraviolet light irradiation. The T-T dimers in hybrids are immunohistochemically recognized using an anti-T-T dimer antibody. In this article, we will present an example of ISH protocol, which works very well both T-T dimer and digoxigenin-labeled probes.

Animals↗

PubMed1998

[Experience of coronary and great vessel angiography by transradial puncture].

The introduction of 5F and even 4F catheters allows transradial coronary arteriography and aortography. The efficacy and limitation of angiography via the radial artery using 5F catheter was prospectively evaluated in 200 consecutive patients. Cardiac catheterization with diagnostic angiography was successfully performed in 198 of 200 patients, including 11 patients with acetylcholine provocation test, 21 with bypass graft angiography, 38 with aortography and 5 with biopsy of the left ventricular myocardium. The transradial approach was not indicated in one patient without normal Allen's test and in one with weak radial pulse. In four patients, guide wire support was needed during manipulation because of marked tortuosity in the innominate artery. The sheath was removed immediately after the completion of the procedure, followed by 5 hours of tourniquet hemostasis without manual compression. The postoperative resting period was reduced. Peripheral vasospasm occurred in 2.5% of cases, but could be eliminated by administration of isosorbide dinitrate and lidocaine. Subcutaneous hemorrhage in the puncture site was observed in 3.0% of cases, but required no additional compression. Transradial catheterization is a minimally invasive, safe and practical alternative to the brachial or femoral artery approach in patients with normal Allen's test.

Aortography↗

PubMed1998

Expression profile of prostate-specific antigen messenger RNA assessed by in situ hybridization is a novel prognostic marker for patients with untreated prostate cancer.

The present study was undertaken to define the relationship between histological grade (Gleason grade) and prostate-specific antigen (PSA) mRNA expression and to evaluate the level of PSA mRNA expression as a possible prognostic marker for untreated prostate cancers. The primary grade areas of 104 prostatic biopsy specimens were analyzed for the expression of PSA mRNA and its protein by nonradioactive in situ hybridization and immunohistochemistry, respectively. A multivariate survival analysis was performed to examine the correlation between PSA mRNA expression and several clinicopathological parameters, e.g., the immunostaining level of PSA protein in biopsy specimens. The percentage of specimens positive for PSA mRNA increased significantly with advanced histological grade. Image analysis of the signal intensity for PSA mRNA showed a significant correlation between the signal intensity in both primary and secondary grade areas of each specimen and the histological grade (P < 0.0001). Only 26.0% of specimens positive for PSA protein were also positive for PSA mRNA (and vice versa, 6.7%). Other tumors were either positive for both (66.3%) or negative for both (1.0%). When the Cox's proportional hazards regression model was used to analyze cancer-specific survival, untreated patients with higher levels of PSA mRNA expression in the higher grade (representing higher grade of either primary or secondary grade) area of tumors were at high risk for cancer-related death (P = 0.017). Furthermore, in cancer-specific survival curves based on PSA mRNA expression status, patients with high levels of PSA mRNA expression in the higher grade area of tumors had a significantly poorer prognosis (P = 0.001), compared with those with tumors expressing low levels of PSA mRNA. Our results suggested that analysis of PSA mRNA expression in specific areas in biopsy specimens of patients with untreated prostate cancer may provide a good assessment of prognosis of prostate cancers.

Aged↗

PubMed1997

Fas/Fas ligand interaction regulates cytotoxicity of CD4+ T cells against staphylococcal enterotoxin B-pulsed endothelial cells.

Infiltration of activated CD4+ T cells and apoptosis of endothelial cells are present in the synovium of rheumatoid arthritis (RA). Using staphylococcal enterotoxin B (SEB) as an antigen, we examined the possible role of antigen (Ag)-dependent activation of CD4+ T cells by endothelial cells, in inducing endothelial cell apoptosis. The human endothelial cell line, EA.hy926 cells, was cultured with or without interferon-gamma (IFN-gamma) and further incubated with CD4+ T cells in the presence or absence of SEB. After this cocultivation, the cytotoxicity and Fas ligand (FasL) expression of CD4+ T cells were examined. A small percentage of EA.hy926 cells expressed HLA-DR and -DQ, and this expression was significantly augmented after IFN-gamma stimulation. Anti-Fas IgM-induced apoptosis was exhibited by both unstimulated and IFN-gamma-stimulated EA.hy926 cells. Cytotoxicity of CD4+ T cells toward SEB-pulsed unstimulated EA.hy926 cells was detected. Furthermore, when CD4+ T cells were incubated with IFN-gamma-stimulated, SEB-pulsed EA.hy926 cells with augmented HLA-DR and -DQ expression, this cytotoxicity was more significant. The addition of anti-HLA-DR and -DQ monoclonal antibodies (mAbs) or human Fas chimeric protein (hFas-Fc) reduced the cytotoxicity. FasL expression was induced in CD4+ T cells cocultured with SEB-pulsed EA.hy926 cells, especially when the EA.hy926 cells were IFN-gamma-stimulated. Furthermore, the addition of mAbs against CD54 and CD58 inhibited both the cytotoxicity and FasL expression of CD4+ T cells induced by SEB-pulsed EA.hy926 cells, indicating the importance of costimulatory molecules on EA.hy926 cells in activating CD4+ T cells. Our results suggest that CD4+ T cells are activated by endothelial cells in an Ag-dependent manner and subsequently express FasL, which induces Fas-mediated apoptosis of endothelial cells. This phenomenon may counteract the growth of RA synovium by inhibiting the proliferation of endothelial cells.

Antibodies, Monoclonal↗

PubMed1997

Frequency of apoptosis relates inversely to invasiveness and metastatic activity in human colorectal cancer.

The frequency of apoptosis was determined in 102 cases of human colorectal cancer. The results were correlated with the frequency of cell proliferation and with clinicopathological characteristics such as degree of differentiation, invasiveness and metastasis. As a marker of apoptosis, intranuclear DNA strand breaks were localized with in situ nick translation (ISNT). As a marker of proliferation, proliferating cell nuclear antigen (PCNA) was localized immunohistochemically. The numbers of nuclei positive with ISNT and for PCNA per 1,000 nuclei on tissue sections were obtained. The labelling indices were compared with clinicopathological characteristics for each tumour. The ISNT labelling index of well differentiated colon carcinomas was higher than that of poorly differentiated carcinomas. Among similarly differentiated cancers, ISNT L.I. of colon carcinomas classified as Dukes A was higher than Dukes B/C, and L.I. of carcinomas which did not metastasize to lymph node or liver was higher than that of carcinomas which metastasized. The PCNA labelling index did not correlate with any of the clinicopathological characteristics or with the ISNT labelling index. The data suggest that apoptosis indices severe as a marker of tumour progression.

Aged↗