bluuebunny/crossref_metadata_2025 huggingface dataset:
Rat bone marrow‐derived dendritic cells, but not ex vivo dendritic cells, secrete nitric oxide and can inhibit T‐cell proliferation
Authors: Powell Timothy J. , Jenkins Chris D. , Hattori Ryuichi , MacPherson G. Gordon
Published: May 2003

The relationships between different dendritic cell (DC) populations are not clearly established. In particular, it is not known how DC generated in vitro relate to those identified in vivo. Here we have characterized rat bone marrow‐derived DC (BMDC) and compared them with DC isolated from spleen (SDC) and pseudo‐afferent lymph (LDC). BMDC express typical DC markers and are mostly OX41 positive and CD4 negative. In contrast to ex vivo DC, some BMDC express Fc receptors. FcR+ and FcR− BMDC express similar levels of major histocompatibility complex class II molecules (MHC) and are B7 positive, but some FcR− BMDC express high levels of B7. In contrast to freshly isolated or cultured ex vivo SDC and LDC, both BMDC subpopulations can express inducible nitric oxide synthase (iNOS) and can secrete nitric oxide (NO) in amounts similar to those secreted by peritoneal macrophages. Despite expressing MHC class II and B7, FcR+ BMDC stimulate only a very weak MLR and inhibit stimulation by FcR− BMDC and ex vivo DC. Inhibition is only partially NO dependent. FcR+ BMDC are not macrophages, as judged by adherence and phagocytosis. Both subpopulations are able to present antigen to primed T cells in vitro and are able to prime naïve CD4 T cells in vivo. However, unlike SDC, BMDC are unable to stimulate cytotoxic T‐lymphocyte (CTL) responses to a minor histocompatibility antigen. Thus, BMDC show marked differences to ex vivo DC and their relationship to those of in vivo DC populations, to date, is unclear.
Analysis of differential immune responses induced by innate and adaptive immunity following transplantation
Authors: He Hongzhen , Stone James R. , Perkins David L.
Published: May 2003

The roles of innate and adaptive immunity in allograft rejection remain incompletely understood. Previous studies analysing lymphocyte deficient or syngeneic graft recipients have identified subsets of inflammatory chemokines and cytokines induced by antigen independent mechanisms. In the current study, we analysed a panel of 60 inflammatory parameters including serum cytokines, intragraft chemokines and cytokines, receptors, and cellular markers. Our results confirmed the up‐regulation of a subset of markers by innate mechanisms and also identified a subset of parameters up‐regulated only in the context of an adaptive response. Thus, we successfully differentiated markers of the innate and adaptive phases of rejection. Current paradigms emphasize that innate signals can promote a subsequent adaptive response. Interestingly, in our studies, expression of the markers induced by innate mechanisms was markedly amplified in the allogeneic, but not syngeneic or lymphocyte deficient, recipients. These results suggest that inflammatory mediators can have functional overlap between the innate and adaptive responses, and that the adaptive component of the rejection process amplifies the innate response by positive feedback regulation.
Isolation of proliferation factor of immature T‐cell clone in concanavalin A‐stimulated splenocyte culture supernatant
Authors: Kohama Yasuhiro , Shinoda Shinji , Hagihara Katsunobu , Hashimoto Takeshi , Yamaguchi Asuka , Nakamura Akihiro , Tsuchiya Takahiro , Tsujikawa Kazutake , Yamamoto Hiroshi
Published: May 2003

An athymic mouse‐derived immature T‐cell clone, N‐9F, was not maintained by interleukin‐2 alone but required another soluble factor, contained in concanavalin A‐stimulated rat splenocyte culture supernatant, namely T cell growth factor (TCGF), for its proliferation. An N‐9F‐proliferation factor (NPF) was isolated in a pure form from TCGF. N‐9F cells and immature thymocytes proliferated in the presence of NPF at 10−11−10−8 g/ml in a dose‐dependent manner, but adult thymocytes were not stimulated by NPF. NPF increased DNA synthesis of N‐9F. NPF increased CD4 and CD8 double negative thymocytes and CD8 single positive thymocytes in fetal thymus organ culture. A hamster anti‐NPF antiserum possessing the capacity to neutralize N‐9F proliferation activity of NPF decreased double negative thymocytes. The amino‐terminal amino acid sequence of NPF was identified to be Ser‐Leu‐Pro‐Cys‐Asp‐Ile‐Cys‐Lys‐Thr‐Val‐Val‐Thr‐Glu‐Ala‐Cys‐Asn‐Leu‐Leu‐Lys‐Asp‐ and was identical to that of rat saposin A. The apparent molecular weight of NPF, 16 000, was comparable to that of saposin A. A rabbit anti‐mouse recombinant His‐tag (mrH)‐saposin A antibody recognized a 16 000 MW molecule in TCGF. A Hitrap‐saposin A antibody column bound NPF and pulled down the NPF activity in TCGF. Thus, NPF in TCGF was a saposin A‐like protein possessing the capacity for growth and differentiation of immature thymocytes.
Infection with chicken anaemia virus impairs the generation of pathogen‐specific cytotoxic T lymphocytes
Authors: Markowski‐Grimsrud Carrie J. , Schat Karel A.
Published: May 2003

Infection with chicken anaemia virus (CAV), a circovirus, can result in immunosuppression and subsequent increased susceptibility to secondary infections. This is the first report of impairment of pathogen‐specific cytotoxic T lymphocytes (CTL) after natural and experimental infection of chickens with CAV and Marek's disease virus (MDV) or reticuloendotheliosis virus (REV). MDV‐ and REV‐specific CTL were generated at 7 days post infection by 9–30‐day‐old‐chickens that were positive for maternal antibodies to CAV at 9–17 days of age. Replication of CAV could not be demonstrated in these chickens using quantitative real‐time polymerase chain reaction (PCR) and reverse transcriptase (RT)–PCR assays. In contrast, REV‐specific CTL failed to develop when chickens negative for maternal antibodies at 9–17 days of age were infected. Infection with CAV at 45 days of age after CAV maternal antibodies had waned also caused a decreased REV‐specific CTL response. In these chickens increased levels of CAV DNA of up to 107 copy numbers per µg DNA and increased relative transcript levels of CAV by up to a factor of 106 were detected by quantitative real‐time PCR and RT–PCR. Interleukin (IL)‐1β and IL‐2 mRNA levels were not significantly affected by CAV infection at 7 or 14 days p.i. Similar assays for interferon‐γ (IFN‐γ) transcripts demonstrated a 10‐fold increase in IFN‐γ mRNA levels at 7 days post infection following REV or REV + CAV infection, while CAV alone caused a two‐ to fourfold increase. These results show a strong link between CAV antibody status, CAV replication, and the ability to generate REV‐specific CTL. It is likely that the immunosuppressive effects of subclinical infection have previously been underestimated.
Assessment of oral transmission using cell‐free human immunodeficiency virus‐1 in mice reconstituted with human peripheral blood leucocyte
Authors: Nakao Ryoma , Hanada Nobuhiro , Asano Toshihiko , Hara Takashi , Abdus Salam Md , Matin Khairul , Shimazu Yoshihito , Nakasone Tadashi , Horibata Shigeo , Aoba Takaaki , Honda Mitsuo , Amagasa Teruo , Senpuku Hidenobu
Published: May 2003

Oral–genital contact is one of the risk factors for the transmission of human immunodeficiency virus (HIV) in adults. In recent reports, oral exposure to simian immunodeficiency virus (SIV) was found to have important implications for the achievement of mucosal transmission of HIV in a rhesus monkey animal model. In the present study, we aimed first to establish a small animal model which did not develop tonsils suitable for HIV oral mucosa transmission, using non‐obese diabetic/severe combined immunodeficiency (NOD/SCID) mice and NOD/SCID B2mnull mice grafted with human peripheral blood leucocytes (hu‐PBL) and stimulated with interleukin (IL)‐4, and second to investigate whether oral exposure to cell‐free R5 and X4 HIV‐1 could lead to oral transmission of HIV through intact or traumatized mucosal tissues in humanized mice. Both low and high concentrations of cell‐free R5 and X4 viruses failed to cause oral transmission with or without trauma in hu‐PBL‐NOD/SCID and NOD/SCID Β2mnull mice, which presented a number of CD4+ cells in gingival tissues and oral cavities with or without tissue injury. The present results show that IL‐4‐administrated NOD/SCID B2mnull mice are useful as a small‐humanized model for the study of HIV oral infection, which may help to define the window of opportunity for oral transmission by the HIV virus in animal model experiments.
Increased interleukin‐10 expression is not responsible for failure of T helper 1 immunity to resolve airborne Mycobacterium tuberculosis infection in mice
Authors: Jung Yu‐Jin , Ryan Lynn , LaCourse Ronald , North Robert J.
Published: May 2003

With a view to determining whether failure of mice to resolve Mycobacterium tuberculosis (Mtb) infection is a consequence of downregulation of T helper 1 (Th1) immunity by interleukin (IL)‐10, mice deleted of the gene for IL‐10 were compared with wild‐type (WT) mice in terms of their ability to make IL‐10 mRNA, generate Th1‐mediated immunity [as measured by synthesis of mRNA for interferon‐γ (IFN‐γ)], IL‐12p40 and inducible nitric oxide synthase (iNOS), and to control lung infection. It was found that the response of WT mice to infection included a substantial and sustained increase in IL‐10 mRNA synthesis in the lungs. A Th1 response in the lungs of WT and IL‐10−/− mice was evidenced by a large and sustained increase in the synthesis of mRNA for IFN‐γ, IL‐12p40 and iNOS, with somewhat higher levels of these mRNA species being made in the lungs of IL‐10−/− mice, particularly at an early stage of infection. However, IL‐10−/− mice were no more capable than WT mice at combating infection.
Age‐related increase of peripheral CD4+ CD8+ double‐positive T lymphocytes in cynomolgus monkeys: longitudinal study in relation to thymic involution
Authors: Lee Won‐Woo , Nam Ki‐Hoan , Terao Keiji , Akari Hirofumi , Yoshikawa Yasuhiro
Published: May 2003

The age‐related increase of peripheral CD4+ CD8+ double‐positive (DP) T cells in cynomolgus monkeys has been reported previously. Because the percentage of DP T cells in cynomolgus monkeys increases abruptly in parallel with the thymic involution occurring at around 11 years of age, it was suggested that thymic involution was associated with this increase. Therefore, a longitudinal study was carried out over 5 years to clarify the exact time when DP T lymphocytes start to increase in relation to the thymic involution. Twelve cynomolgus monkeys at 6 years of age were classified into three groups, based on their percentage of DP T cells, as follows: DP‐High (>5% DP T cells); DP‐Middle (1–5% DP T cells); and DP‐Low (<1% DP T cells). In the DP‐High group, the percentage of DP T cells showed an abrupt increase, of >10%, in monkeys at 7 years of age, and the prevalence of this subset correlated with a distinctive increase in the percentage of memory T cells (CD4+ CD29high, CD8+ CD28−), indicating an association with the maturation of immune function, including thymic involution. To assess the thymic function, the coding joint of T‐cell receptor excision circles (cjTREC) levels in sorted T cells were analysed by polymerase chain reaction (PCR)‐enzyme‐linked immunosorbent assay (ELISA). The cjTREC in the T cells of the DP‐High group (4362 ± 3139 copies/105 T cells) was significantly lower than that (22 722 ± 4928 copies/105 T cells) of the DP‐Low group. Moreover, the mean copy number of cjTREC in naive T cells was also significantly different between the DP‐High and the DP‐Low group (0·457 ± 0·181 and 1·141 ± 0·107, respectively). These findings suggest that thymic involution has an influence on the age‐related increase of DP T cells in cynomolgus monkeys.
NIM‐R7, a novel marker for resting B1 and marginal‐zone B lymphocytes, is also expressed on activated T and B cells
Authors: Manjarrez‐Orduño Nataly , Parkhouse R Michael E. , Santos‐Argumedo Leopoldo
Published: May 2003

In mice, follicular B cells have been studied in detail, while two other B‐cell subpopulations – marginal‐zone B and B1 cells – are less well understood. In this work we report the expression pattern of p58, a lymphocyte‐activation marker, recognized by rat monoclonal antibody, NIM‐R7, and present on the latter two cell subpopulations. Staining with NIM‐R7 showed that undisturbed marginal‐zone B cells, as well as peritoneal cavity and splenic B1a cells, constitutively expressed p58, whereas follicular B cells and resting T lymphocytes did not. Ontogenic analysis of different compartments showed that p58 did not appear at any stage of development, prior to the development of mature T or B2 lymphocytes. Upon polyclonal stimulation, however, p58 appeared on both T and B2 lymphocytes. Finally, ricin A‐conjugated NIM‐R7 was able to kill the BCL1 lymphoma without effect on mature resting B2 cells. Therefore, p58 may be a potential target for diagnosis or therapy of B1 and marginal‐zone B‐cell malignancies.
Costimulation through OX40 is crucial for induction of an alloreactive human T‐cell response
Authors: Ukyo Naoya , Hori Toshiyuki , Yanagita Soshi , Ishikawa Takayuki , Uchiyama Takashi
Published: May 2003

The alloreactive immune response is a series of events initiated by the interaction of T cells with allogeneic dendritic cells (DCs), involving alloantigen recognition and costimulatory signals. In this study, we investigated the role of OX40 in alloreactivity in vitro. We first demonstrated that anti‐OX40 ligand (anti‐OX40L) monoclonal antibody (mAb) could markedly suppress the mixed leucocyte reaction (MLR) of peripheral blood mononuclear cells (PBMC). To further define the contribution of the OX40/OX40L system to the MLR, we set up a co‐culture system of CD4+ T cells and allogeneic monocyte‐derived dendritic cells (DCs). After 2 days, OX40 expression was induced on CD4+ T cells and this induction was strongly inhibited by the addition of cytotoxic T lymphocyte‐associated antigen‐4 (CTLA‐4)–Fc fusion protein, suggesting that the expression of OX40 during alloreaction is dependent on CD28 signalling. Next we examined the effects of anti‐OX40L mAb, CTLA‐4–Fc fusion protein and anti‐human leucocyte antigen (HLA)‐DR mAb on the proliferative response of CD4+ T cells to allogeneic DCs. The proliferation of T cells was almost completely suppressed by anti‐OX40L mAb, which was comparable with that of CTLA‐4–Fc. Measurement of interleukin‐2 (IL‐2) production in the culture supernatants showed that suppression of a proliferative response was at least in part ascribed to reduced IL‐2 production. Furthermore, purified OX40L− allogeneic DCs could induce considerable proliferation of CD4+ T cells, which was suppressed by anti‐OX40L mAb. These results suggest that the OX40/OX40L system is crucial for induction of the allogeneic T‐cell response and the OX40/OX40L system is subsequent to and dependent on CD28 signalling, but is crucial for the end outcome of the human alloreactive T‐cell response.
Soluble FcγRIIa inhibits rheumatoid factor binding to immune complexes
Authors: Wines Bruce D. , Gavin Amanda , Powell Maree S. , Steinitz Michael , Buchanan Russell R. C. , Mark Hogarth P.
Published: May 2003

Soluble low‐affinity receptors for IgG are known to inhibit immune complex (IC)‐mediated inflammation, and expression by leukocytes is elevated in several inflammatory diseases. Immunoglobulin M (IgM) rheumatoid factors (RF), anti‐Fc autoantibodies, are found in autoimmune diseases, such as rheumatoid arthritis (RA), as well as in normal immune responses. This study demonstrated that soluble FcγRIIa inhibits the interaction of rheumatoid factors with ICs. The recombinant soluble low‐affinity FcγR, rsFcγRIIa, partially inhibited (30–70%) the rate of precipitation of soluble ICs by RF‐positive RA sera. This required the normal interaction of FcγRIIa with Fc as the effect could be abrogated with the Fab fragment of the blocking mAb IV‐3. Furthermore, rsFcγRIIa partially inhibited (40%) the binding of a monoclonal IgM RF (RF‐AN) to an IC formed by IgG2 antibody binding to an antigen‐coated biosensor chip. Since RF‐AN has been characterized by crystallography to bind to the CH2/CH3 interface of the IgG‐Fc, and leukocyte FcγRIIa binds to a distinct site centred on the lower hinge, this inhibition is uncompetitive. Some inhibition (15%) of staphylococcal protein A binding to IC was also observed. As soluble FcγRIIa disrupts Fc:Fc interactions in IgG‐ICs, we propose that this alteration of the IC also reduces the accessibility of Fc portions in the IC, resulting in the partial inhibition of ligands, particularly IgM RF, which bind Fc. We propose that the high concentrations of soluble FcγR found during inflammation can affect the properties of ICs and their interaction with the immune system.
Effect of cytofectins on the immune response of murine macrophages to mammalian DNA
Authors: Zhu Fu‐Gang , Reich Charles F. , Pisetsky David S.
Published: May 2003

DNA, depending on base sequence, can induce a wide range of immune responses. While bacterial DNA is stimulatory, mammalian DNA is inactive alone and can, moreover, inhibit the response to bacterial DNA. To determine whether the mode of cell entry affects the immune properties of mammalian DNA, we have investigated the effects of the cytofectin agents Fugene 6 (Roche Diagnostics Corp., Indianapolis, IN), Lipofectin and Lipofectamine (Life Technologies, Grand Island, NY) on the responses of murine macrophages to DNA from calf thymus and human placenta. Whereas calf thymus and human placenta DNA alone failed to stimulate J774 or RAW264·7 cell lines or bone marrow‐derived macrophages, these DNAs in complexes with cytofectin agents stimulated macrophages to produce nitric oxide but not interleukin 12. Both single‐stranded and double‐stranded DNAs were active in the presence of cytofectins. Macrophage activation by the DNA–cytofectin complexes was reduced by chloroquine, suggesting a role of endosomal acidification in activation. As shown by flow cytometry and confocal microscopy, the cytofectins caused an increase in the uptake of DNA into cells. Our findings indicate that macrophages vary in their response to DNA depending on uptake pathway, suggesting that activation by DNA reflects not only sequence but also context or intracellular location.
Immunotherapy of spontaneous mammary carcinoma with fusions of dendritic cells and mucin 1‐positive carcinoma cells
Authors: Chen Dongshu , Xia Jianchuan , Tanaka Yasuhiro , Chen Hongsong , Koido Shigeo , Wernet Oliver , Mukherjee Pinku , Gendler Sandra J. , Kufe Donald , Gong Jianlin
Published: May 2003

The tumour‐associated antigen mucin 1 (MUC1) is a multifunctional protein involved in protection of mucous membranes, signal transduction, and modulation of the immune system. More than 70% of cancers overexpress MUC1, making MUC1 a potential target for immunotherapy. In the present study, MUC1 transgenic mice were crossed with syngeneic strains that express the polyomavirus middle‐T oncogene (PyMT) driven by the mouse mammary tumour virus promoter long‐terminal repeat (MMTV‐LTR). The resultant breed (MMT mice) developed spontaneous MUC1‐expressing mammary carcinomas with 100% penetrance at 8–15 weeks of age. As found in human breast cancer, the mammary carcinoma in MMT mice arose in multiple stages. Immunization with fusions of dendritic cells and MUC1‐positive tumour cells (FC/MUC1) induced MUC1‐specific immune responses that blocked or delayed the development of spontaneous breast carcinomas. In contrast, there was no delay of tumour development in MMT mice immunized with irradiated MC38/MUC1 tumour cells. The efficacy of fusion cells was closely correlated with the timing of initial immunization. Immunization with FC/MUC1 initiated in MMT mice at < 1, 1–2 and 2–3 months of age rendered 33, 5 and 0% of mice free of tumour, respectively, up to 6 months. Whereas mice immunized in the later stage of tumour development succumbed to their disease, immunization resulted in control of tumour progression and prolongation of life. These results indicate that immunization with FC/MUC1 can generate an anti‐MUC1 response that is sufficient to delay the development of spontaneous mammary carcinomas and control tumour progression in MMT mice.
Innate self recognition by an invariant, rearranged T‐cell receptor and its immune consequences
Authors: Stanic Aleksandar K. , Park Jang‐June , Joyce Sebastian
Published: May 2003

This review attempts to illuminate the glycolipid antigen presentation properties of CD1d, how CD1d controls the function of natural T (iNKT) cells and how CD1d and iNKT cells interact to jump‐start the immune system. It is postulated that the CD1d‐iNKT cell system functions as a sensor, sensing alterations in cellular lipid content by virtue of its affinity for such ligands. The presentation of a neo‐self glycolipid, presumably by infectious assault of antigen‐presenting cells, activates iNKT cells, which promptly release pro‐inflammatory and anti‐inflammatory cytokines and jump‐start the immune system.
Host's innate immune response to fungal and bacterial agents in vitro: up‐regulation of interleukin‐15 gene expression resulting in enhanced natural killer cell activity
Authors: Tran Phay , Ahmad Rasheed , Xu Jingwu , Ahmad Ali , Menezes José
Published: May 2003

Natural killer (NK) cells play an important role in the first line of defence against viral infections. We have shown earlier that exposure of human peripheral blood mononuclear cells (PBMC) to viruses results in rapid up‐regulation of NK cell activity via interleukin‐15 (IL‐15) induction, and that this mechanism curtails viral infection in vitro. By using Candida albicans, Escherichia coli and Staphylococcus aureus, we now show here that exposure of PBMC to fungi and bacteria also results in an immediate increase of NK cytotoxicity. Reverse transcriptase–polymerase chain reaction and Western blot analyses as well as the use of antibodies against different cytokines revealed that IL‐15 induction played a predominant role in this NK activation. These results indicate that IL‐15 is also involved in the innate immune response against fungal and bacterial agents.
The combination of plasmid interleukin‐12 with a single DNA vaccine is more effective than Mycobacterium bovis (bacille Calmette–Guèrin) in protecting against systemic Mycobacterim avium infection
Authors: Martin Ela , Kamath Arun T. , Briscoe Helen , Britton Warwick J.
Published: May 2003

Sub‐unit vaccines utilizing purified mycobacterial proteins or DNA vaccines induce partial protection against mycobacterial infections. For example, immunization with DNA vaccines expressing the gene for the immunodominant 35 000 MW protein, common to Mycobacterium avium and Mycobacterium leprae but absent from the Mycobacterium tuberculosis complex, conferred significant protection against infection with either virulent M. avium or M. leprae in mice. However, the level of protection was equivalent to that obtained with the viable, attenuated vaccine, Mycobacterium bovis, bacille Calmette–Guèrin (BCG). The cytokine, interleukin (IL)‐12, is essential for priming naïve CD4+ T lymphocytes to differentiate into interferon‐γ (IFN‐γ)‐secreting T cells. We have used a novel self‐splicing vector expressing both chains of murine IL‐12 to determine if plasmid IL‐12 would increase the efficacy of a vaccine expressing the M. avium 35 000 MW protein (DNA‐Av35). Co‐immunization with p2AIL‐12 and DNA‐Av35 led to a significant increase in the number of antigen‐specific IFN‐γ secreting cells and total amount of IFN‐γ released, but a concomitant fall in the antibody response to the 35 000 MW protein. This pattern of response was associated with enhanced clearance of M. avium from the liver and spleen of coimmunized mice, and was significantly more effective than BCG or DNA‐Av35. alone. Following M. avium challenge there was significant increase in the expansion of the 35 000 MW antigen‐reactive T cells in the coimmunized mice. Therefore, plasmid‐delivered IL‐12 acts as an effective adjuvant to increase the protective efficacy of a single DNA vaccine against M. avium infection above that achieved by BCG, and this strategy may improve the efficacy of subunit vaccines against M. leprae and M. tuberculosis.
Hyporesponsiveness of murine B lymphocytes exposed to the filarial nematode secreted product ES‐62 in vivo
Authors: Wilson Emma H. , Deehan Maureen R. , Katz Elad , Brown Kirsty S. , Houston Katrina M. , O'Grady John , Harnett Margaret M. , Harnett William
Published: May 2003

ES‐62 is a phosphorylcholine (PC)‐containing glycoprotein secreted by filarial nematodes, parasites of vertebrates including humans. We have previously demonstrated that pre‐exposure to this molecule in vitro interferes with subsequent B‐cell receptor (BCR)‐dependent activation of murine splenic B lymphocytes. To investigate the significance of this during filarial nematode infection, we now employ mice exposed to ES‐62, at concentrations equivalent to those found for PC‐containing molecules in the bloodstream of parasitized humans, via release from implanted osmotic pumps. Using this approach, we reveal that splenic and lymph node mononuclear cells, and also purified splenic B cells recovered from these mice have reduced ability ex vivo to proliferate in response to BCR ligation. The effect on BCR‐induced proliferation was further investigated with respect to elucidating the mechanism of action of the parasite product and was shown to be associated with impaired signal transduction affecting the ErkMAPkinase pathway. Also, it was found that ES‐62 did not act by promoting apoptosis or by priming for apoptosis following subsequent stimulation, but rather, appeared to render cells hyporesponsive to stimulation. ES‐62 is thus shown for the first time to be a potent modulator of B lymphocyte function in vivo at a concentration relevant to natural filarial nematode infection. This finding considerably strengthens the idea that ES‐62 plays a role in evasion of the immune response during parasitism.
Erectile dysfunction after surgical treatment*
Authors: Mirone Vincenzo , Imbimbo Ciro , Palmieri Alessandro , Longo Nicola , Fusco Ferdinando
Published: May 2003

Erectile dysfunction is a recognized complication of prostate and bladder radical surgery, although there is significant variation in the reported risk, much of this variability is related to the retrospective nature of most previous studies. Undoubtedly, the quality of life of bladder and prostate cancer patients would be much improved if both normal micturition and potency are preserved, which is the subject of this article. Quality of life studies can delineate sexual function after radical prostatectomy, including the use of sexual aids. Penile erection is a neurovascular event modulated by neurotransmitters and hormonal status. The penis is innervated by autonomic and somatic nerves. Both surgery and radiation therapy appear to affect such a mechanism. Radiation is thought to produce Erectile Dysfunction (ED) by accelerating microvascular angiopathy causing cavernosal fibrosis or stenosis of the pelvic arteries and by accelerating existing arteriosclerosis, leading to vascular impotence. Years may elapse before clinically significant ED occurs. Criteria that influence recovery of erections after surgery include younger patient age, stronger erections before operation, preservation of the neurovascular bundles, and attention to fine details in the surgical technique. Recovery of erections occurs in 68% of preoperatively potent men treated with bilateral nerve‐sparing surgery and in 47% of those treated with unilateral nerve‐sparing surgery.
Suppression of testosterone stimulates recovery of spermatogenesis after cancer treatment
Authors: Meistrich Marvin L. , Shetty Gunapala
Published: May 2003

It is important to develop methods to prevent or reverse the infertility caused by chemotherapy or radiation therapy for cancer in men. Radiation and some chemotherapeutic agents kill spermatogonial stem cells, but we have shown that these cells survive in rats, although they are unable to differentiate. There is evidence that this phenomenon also occurs in men. The block to spermatogonial differentiation in rats is caused by some unknown change, either in the spermatogonia or the somatic elements of the testis, such that testosterone inhibits spermatogonial differentiation. In the rat, the spermatogenesis and fertility lost following treatment with radiation or some chemotherapeutic agents can be restored by suppressing testosterone with gonadotropin releasing hormone (GnRH) agonists or antagonists, either before or after the cytotoxic insult. The applicability of this procedure to humans is still unknown. Some anticancer regimens may kill all the stem cells, in which case the only option would be spermatogonial transplantation. However, in some cases stem cells survive and there is one report of stimulation of recovery of spermatogenesis with hormonal treatment. Clinical trials should focus on treating patients with hormones during or soon after anticancer treatment. The hormone regimen should involve suppression of testosterone production with minimum androgen supplementation used to improve the diminished libido.
Male age is not an independent factor to affect the outcome of assisted reproductive techniques
Authors: Kumtepe Yakup , Yakin Kayhan , Kahraman Semra , Sertyel Semra , Vanlioğlu Faruk , Cengiz Sami , Dönmez Ersan
Published: May 2003

Controversy exists whether advanced male age is associated with poor sperm quality and subsequent failure in the assisted reproductive techniques (ART). The purpose of this study was to evaluate the effect of male age on sperm quality and the outcome of ART as well as the association of male age with other relevant factors, particularly with the female age. A retrospective study was performed in order to evaluate the effect of male age on the sperm parameters in 880 routine seminal analyses. Additionally, sperm parameters were also compared among different age groups in 919 cases with male factor infertility who had been included in an ART programme. The laboratory and clinical results of ART (fertilization rate, number and quality of embryos transferred, as well as pregnancy rates) were compared according to different age groups. The results were also evaluated by one‐way correlation and also step‐wise logistic regression analysis to identify the interactions and correlations between different parameters. There were no statistically significant differences between male age groups in terms of sperm concentration, motility and morphology either in routine seminal analyses or in ART groups. In the ART group, a statistically significant linear correlation was present between male and female ages. Male age was increasing in parallel to female age. Female age was also correlated significantly with ART results. In one‐way correlation analysis, male age was found to be correlated with the pregnancy rate, but not with fertilization rate and the quality of the transferred embryos. However, regression analysis revealed that correlation between male age and pregnancy results was simply dependent on the effect of the female age. Seminal parameters did not reveal a significant change with the increasing male age. The effect of male age on ART results in cases with male factor infertility is not a direct effect but a reflection of the negative impact of the parallel increase in the female age.
Microtubule‐associated epithelial protein E‐MAP‐115 is localized in the spermatid manchette
Authors: Penttilä Tarja‐Leena , Parvinen Martti , Paranko Jorma
Published: May 2003

A microtubule‐associated protein E‐MAP‐115 has been originally isolated and characterized from HeLa cells. Because of its predominant expression in cultured cells of epithelial origin, it has been suggested to be involved in the regulation of cell polarization. The present immunocytochemical, Northern blot and in situ hybridization analysis of E‐MAP‐115 in the mouse and rat seminiferous epithelium indicates its distinct association with the spermatid manchette, a unique microtubular structure which appears in the cytoplasm of spermatids at step 8 when nuclear polarization and elongation starts. At steps 15–16 when manchette has been disassembled, immunoreactivity for E‐MAP‐115 disappeared. At immunoelectron microscopical level, E‐MAP‐15 was associated with the microtubules of the manchette. In the Western and Northern blot analysis, a distinct stage‐dependent expression of a single E‐MAP‐115 polypeptide and two mRNA species (3.4 and 2.4 kb) could be identified. MTEST 60, a spermatid‐specific transcript, showed a 100% homology over region of 68–193 bp of E‐MAP‐115 sequence. The reported specific localization of E‐MAP‐115 to the spermatid manchette strongly supports its role as a regulator of cell polarization. This, in turn, supports the hypotheses concerning the dynamic function of the manchette during spermiogenesis.
TGF‐βs: their role in testicular function and Sertoli cell tight junction dynamics
Authors: Lui Wing‐Yee , Lee Will M. , Cheng C. Yan
Published: May 2003

Transforming growth factor‐βs (TGF‐βs) are known to regulate multiple physiological functions in the testis, which include spermatogenesis, Leydig cell steroidogenesis, extracellular matrix synthesis and testis development. More recent studies have shown that TGF‐β3 also regulates Sertoli cell tight junction (TJ) dynamics in vitro via the p38 mitogen‐activated protein (MAP) kinase pathway, suggesting that this cytokine plays a crucial role in regulating the opening and closing of the blood–testis barrier (BTB). This in turn regulates the passage of pre‐leptotene and leptotene spermatocytes across the BTB at stages VIII‐XI of the seminiferous epithelial cycle. This review summarizes recent advances of studies on TGF‐βs in the testis, highlighting their regulatory role in TJ dynamics.
Effects of hepatocyte growth factor on urokinase‐type plasminogen activator (uPA) and uPA receptor in DU145 prostate cancer cells
Authors: Nishimura Kenji , Matsumiya Kiyomi , Miura Hidenobu , Tsujimura Akira , Nonomura Norio , Matsumoto Kunio , Nakamura Toshikazu , Okuyama Akihiko
Published: May 2003

Urokinase‐type plasminogen activator (uPA) and the uPA receptor (uPAR) are involved in a proteolytic cascade resulting of extracellular matrix degradation. Upstream, uPA and uPAR are regulated by various factors including hepatocyte growth factor (HGF), which stimulates the uPA/uPAR proteolytic system and increases invasion of cancers. We recently demonstrated that HGF induces invasion of DU145 prostate cancer cells into collagen gel matrix. We therefore examined effects of HGF on uPA and uPAR expression in DU145 cells. Effects of HGF on uPA expression in culture medium were determined by Western blotting and fibrin zymography, effects on uPAR expression in cell‐associated protein were examined by Western blotting. HGF increased uPA and uPAR production in a dose‐dependent manner up to 10 ng/mL, while effects of 20 ng/mL were approximately equal to those of 10 ng/mL. HGF stimulated uPA production beyond that in control cultures from 8 h until 48 h after HGF addition. HGF stimulated a uPA/uPAR proteolytic network in DU145 cells, which may be important for acquisition invasive potential by prostate cancer.
The polymorphic androgen receptor gene CAG repeat, pituitary–testicular function and andropausal symptoms in ageing men
Authors: Härkönen Kati , Huhtaniemi Ilpo , Mäkinen Juha , Hübler Doris , Irjala Kerttu , Koskenvuo Markku , Oettel Michael , Raitakari Olli , Saad Farid , Pöllänen Pasi
Published: May 2003

The activity of androgen receptor (AR) is modulated by a polymorphic CAG trinucleotide repeat in the AR gene. In the present study, we investigated hormonal changes among ageing men, and whether the number of AR CAG triplets is related to the appearance of these changes, as well as symptoms and diseases associated with ageing. A total of 213 41–70‐year‐old men donated blood for hormone analyses (LH, testosterone, oestradiol and SHBG) and answered questions concerning diseases and symptoms associated with ageing and/or androgen deficiency. Of these men, 172 donated blood for the measurement of the CAG repeat length of AR. The CAG repeat region of the AR gene was amplified by polymerase chain reaction (PCR) and the products were sized on polyacrylamide gels. The repeat number was analysed as a dichotomized variable divided according to cut‐off limits of the lowest (≤20 repeats) and the highest quartile (≥23 repeats), and as a continuous variable. The proportion of men with serum LH in the uppermost quartile (>6.0 IU/L) with normal serum testosterone (>9.8 nmol/L, above the lowest 10%) increased significantly with age (p = 0.01). There were fewer men with this hormonal condition among those with CAG repeat number in the uppermost quartile (≥23 repeats) (p = 0.03). These men also reported less decreased potency (p < 0.05). The repeat number was positively correlated with depression, as expressed by the wish to be dead (r = 0.45; p < 0.0001), depressed mood (r = 0.23; p = 0.003), anxiety (r = 0.15; p < 0.05), deterioration of general well‐being (r = 0.22; p = 0.004), as well as decreased beard growth (r = 0.49; p < 0.0001). A hormonal condition where serum testosterone is normal but LH increased is a frequent finding in male ageing. Only certain types of age‐related changes in ageing men were associated with the length of the AR gene CAG repeat, suggesting that this parameter may play a role in setting different thresholds for the array of androgen actions in the male.
A stereological study of the effects of experimental inguinal cryptorchidism and subsequent orchiopexy on spermatogenesis in adult monkeys
Authors: Zhang R. D. , Peng B. , Deng X. Z. , Wan Y. , Yang Z. W.
Published: May 2003

Our previous study demonstrated that experimental intra‐abdominal cryptorchidism in adult rabbits for 13 weeks resulted in severe spermatogenic arrest: type A spermatogonia was the only germ cell type seen in the seminiferous epithelium and its number per testis was reduced by 84%. Seven weeks following orchiopexy, the type A spermatogonial number returned to the near‐normal range in most animals and spermatogenesis partially recovered (Reproduction 2002, 124, 95–105). This study aimed to determine whether inguinal cryptorchidism would produce less‐severe damage to spermatogenesis and whether subsequent orchiopexy would better restore spermatogenesis. Five normal adult male rhesus monkeys (Macaca mulatta) underwent bilateral artificial inguinal cryptorchidism. Half a year later, one testis together with the ipsilateral epididymis were removed from each animal and then unilateral orchiopexy was performed on the contralateral side, with the remaining testis and epididymis being removed another half a year later. A contemporary unbiased and efficient stereological tool, the optical disector, was used to estimate numbers of all types of spermatogenic cells in the testis and spermatozoa in the epididymis. Spermatogenic arrest was induced by cryptorchidism at the stage of spermatogonia (n = 1), spermatocytes (n = 2) or early spermatids (n = 1), with the type A spermatogonial numbers per testis being reduced to 14.8–57.2% of the control average; in one of the five cryptorchid animals, however, spermatogenesis remained normal. Subsequent orchiopexy, which was successfully performed on two animals with cryptorchidism‐induced spermatogenic arrest, brought on a full or partial recovery of spermatogenesis. In conclusion, inguinal cryptorchidism induces less severe (in comparison with an intra‐abdominal one) and variable damage to spermatogenesis, which is restored, at least in part, by subsequent orchiopexy.
Interactions between root‐infecting fungi and plant density in an annual legume, Kummerowia stipulacea
Authors: Mihail J.D. , Alexander H.M. , Taylor S.J.
Published: May 2003

Population dynamics of an annual legume, Kummerowia stipulacea, were followed in permanent plots in a mown field for 4 years. There was a large reduction in the number of plants within seasons.

Laboratory studies showed that biotic factors were responsible for seed death in the soil. Using soil from the field plot location, we isolated fungi pathogenic to K. stipulacea seeds and seedlings.

Two pathogenic fungi (Rhizoctonia solani and Pythium irregulare) were used in a glasshouse study of the effects of pathogens and intraspecific competition on plant mortality and growth. Our null hypothesis was that death of individual plants due to disease would be balanced by increased growth of survivors. A factorial experiment was established with five soil treatments (three controls, P. irregulare and R. solani) and seven seed densities.

Inoculation by both R. Solani and P. irregulare led to a reduction in final numbers of plants, with the reduction greatest for populations inoculated with R. solani. Average biomass per plant was reduced with increased sowing density in all treatments except the R. solani inoculation, where surviving plants in high‐density pots may be larger because of the reduced density resulting from pathogen‐induced death. No treatment differences in size hierarchies were evident.

Surviving plants in both inoculation treatments could not take full advantage of the reduced density, and thus total biomass and number of trifoliate leaves per population (a surrogate for seed production) were reduced compared to controls, leading us to reject the null hypothesis. The reduction was more severe at high sowing densities. These results suggest that disease has the potential to reduce seed production and thus plant population numbers, if populations are seed limited. Shapes of yield‐sowing density relationships were asymptotic for all treatments; thus, disease‐induced ‘overcompensation’ leading to fluctuating population dynamics was not suggested.
Yield–density functions as predictors of community structure in a serpentine annual grassland
Authors: Moloney Kirk A. , Chiariello Nona
Published: May 2003

Two series of competition experiments involving the four annual plant species Bromus hordeaceus, Calycadenia multiglandulosa, Plantago erecta and Microseris douglasii were conducted in an experimental array of pots located at the Jasper Ridge Biological Preserve, San Mateo County, California, USA. One experiment was conducted during the 1988‐89 growing season, the other during the 1989‐90 growing season.

A four‐species yield‐density model was constructed using seed yield data from the 1988‐89 experiment. Model predictions were tested against seed yield data from the 1989‐90 experiment. A systematic bias in predicted seed yields was found. As a consequence, the original model was reparameterized to provide a better fit to the observed yields for the 1989‐90 experiment.

Analyses were conducted to determine the importance of potential sources of bias in the original model, including (i) mis‐specification of density effects at low densities due to the parameterization protocol; (ii) interaction effects among competing species; and (iii) year‐to‐year variability in competitive interactions. All three sources had a significant effect on at least one of the species in the experiment, although significant sources differed between species.

Using two forms of sensitivity analysis, a comparison was made between the original and modified versions of the yield–density model to determine how they differed in predictions of long‐term plant community dynamics. Rank order of average densities among species did not differ between models; however, there were several important differences in their predictions with respect to overall community structure. Implications of these results with respect to the use of yield–density models in studying plant community dynamics are discussed.

The present study indicates that the effectiveness of the generally employed yield–density model at characterizing competitive interactions under different environmental conditions depends upon the criteria employed in making an assessment. One possible explanation is that competitive interactions within the serpentine community are highly sensitive to changes in environmental conditions and we found some evidence for this in Calycadenia and Plantago
The ecology of the climbing fern Dicranopteris linearis on windward Mauna Loa, Hawaii
Authors: Russell Ann E. , Raich James W. , Vitousek Peter M.
Published: May 2003

Dicranopteris linearis (Gleicheniaceae), a native fern common throughout the Old World tropics and Polynesia, forms dense thickets > 3m deep over large areas of open‐canopy, oligotrophic, wet Hawaiian rainforests. Our objectives were to identify leaf‐ and whole plant‐level traits that are key to its success and to determine its community‐and ecosystem‐level consequences in primary successional sites.

Along an elevational gradient from 90 to 1660m, mean maximum net assimilation rates of Dicranopteris ranged from 2.9 to 5.0 μmol m−2 s−1, compared with 3.6–9.5 μmol m−1 s−1 in the codominant tree Metrosideros polymorpha. Gas‐exchange characteristics did not explain Dicranopteris' success, nor its trends in production.

However, indeterminate, clonal growth form, shallow rhizomes, marcescent leaves with low decomposability, and a mat‐forming capacity enabled Dicranopteris to colonize sites and to maintain dominance via high effective leaf area, despte its low biomass. Phosphorus use efficiency, which reached 24 kg g−1, was exceptionally high, allowing colonization of phosphorus‐poor sites.

Dicranopteris contributed up to 74% of above‐ground net primary productivity in a site where it contained only 14% of live biomass. It accounted for up to 57% and 47% of total nitrogen and phosphorus uptake by plants, respectively, where it contained only 24% and 30% of plant nitrogen and phosphorus. Dicranopteris leaves are short‐lived and slow to decompose; thus, fixed carbon is transferred quickly to soil detrital pools where it contributes to aggrading soil organic matter pools and may exacerbate oligotrophic conditions, thereby strongly influencing soil genesis and ecosystem development.

The fern therefore influences forest‐floor light regimes and directs later community development. An exclusion experiment demonstrated that Dicranopteris competed with Metrosideros, but lack of revegetation in 40% of the exclusion area after 39 months showed that Dicranopteris also colonized microenvironments unavailable to its endemic codominants. Dicranopteris may play an important role in resisting invasions of exotic species into Hawaiian rainforests.