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Macrophage colony-stimulating factor (CSF1) controls the proliferation and differentiation of cells of the mononuclear phagocyte system. CSF1, alongside a second ligand, interleukin-34 (IL-34), acts by binding to a cell surface receptor (CSF1R). We previously cloned and expressed pig CSF1 and IL-34. Here we produced a pig CSF1R-Ig+pFUSE Fc fusion protein and used it as an immunogen to produce three monoclonal antibodies (ROS8G11, ROS3A5 and ROS3B10) targeted against porcine CSF1R. Specific binding of each monoclonal antibody was confirmed by ELISA, Western blot, flow cytometry and immunocytochemistry. The antibodies did not block CSF1 signalling. The surface expression of CSF1R in pig peripheral blood was restricted to CD14-positive monocytes and was also detected on lung macrophages. These antibodies provided an opportunity to investigate the increase of available CSF1R during pig BMDM differentiation. The new monoclonal antibodies provide useful reagents to support the study of monocyte and macrophage biology in the pig.

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Testosterone synthesis depends on normal Leydig cell (LC) development, but the mechanisms controlling this development remain unclear. We recently demonstrated that androgen receptor (AR) ablation from a proportion of testicular peritubular myoid cells (PTM-ARKO) did not affect LC number, but resulted in compensated LC failure. The current study extends these investigations, demonstrating that PTM AR signalling is important for normal development, ultrastructure and function of adult LCs. Notably, mRNAs for LC markers [e.g. steroidogenic factor 1 (Nr5a1), insulin-like growth factor (Igf-1) and insulin-like factor 3 (Insl3)] were significantly reduced in adult PTM-ARKOs, but not all LCs were similarly affected. Two LC sub-populations were identified, one apparently 'normal' sub-population that expressed adult LC markers and steroidogenic enzymes as in controls, and another 'abnormal' sub-population that had arrested development and only weakly expressed INSL3, luteinizing hormone receptor, and several steroidogenic enzymes. Furthermore, unlike 'normal' LCs in PTM-ARKOs, the 'abnormal' LCs did not involute as expected in response to exogenous testosterone. Differential function of these LC sub-populations is likely to mean that the 'normal' LCs work harder to compensate for the 'abnormal' LCs to maintain normal serum testosterone. These findings reveal new paracrine mechanisms underlying adult LC development, which can be further investigated using PTM-ARKOs.

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The aims of this study were to examine the anti-proliferative effects of different concentrations of a commercial preparation of conjugated linoleic acids (CLA) mixture of isomers [cis-9, trans-11 CLA (c9,t11 CLA): trans-10, cis-12 CLA (50:50)] and their constituent isomers on PC-3, a human prostatic carcinoma cell line, and to study their effects on gene expression (mRNA and protein levels) of different enzymes and oncoproteins involved in oncogenesis and progression of prostate cancer. This includes pathways for arachidonic acid metabolism [cyclooxygenase 1 (COX-1), 2 (COX-2) and 5-lipoxygenase (5-LOX)], apoptosis (bcl-2) and cell cycle control (p21(WAF/Cip1)). Our results indicate a significant decrease in PC-3 proliferation elicited by CLA, although with high variability between isomers. The trans-10, cis-12 CLA was the most effective isomer (55% inhibition). This isomer was also able to decrease bcl-2 gene expression and to increase p21(WAF1/Cip1) mRNA levels (60% increase at highest concentration). In contrast, cis-9, trans-11 had no effect on these proteins but had a clear effect on 5-LOX expression and to a lesser degree on COX-2 protein level isomers. In conclusion, the anti-proliferative effects on PC-3 of CLA mixture and their constituent isomers are not equivalent, due to the different pathways involved for individual isomers. Trans-10, cis-12 seems to work preferentially through modulation of apoptosis and cell cycle control, while c9,t11 CLA isomer affects arachidonic acid metabolism.

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Infectious mononucleosis in its classical presentation consists of the clinical triad of fever, pharyngitis, and cervical lymphadenopathy. The majority of cases are caused by primary infection with the Epstein-Barr virus (EBV). There is, however, a wide clinical spectrum of disease manifestations, including pulmonary, hematologic, and neurologic findings and a series of associated laboratory abnormalities, such as lymphocytosis, heterophile antibodies, and anti-EBV antibodies. The disease is typically self-limited and treated with supportive therapy only. Rarely, serious complications such as airway obstruction, severe thrombocytopenia, or severe hemolytic anemia can occur. Infectious mononucleosis does not cause congenital anomalies, and pregnant women are not at increased risk of serious complications resulting from the disorder.

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Screening has been applied to normal populations to detect early cancers. Prostate cancer is very common and can be detected at an early stage. Screening has not been introduced in the UK for this disease and the possible reasons for this are discussed. There is a strong case for evaluation of screening programmes for this disease.

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Arterial or 'high-flow' priapism is a rare complication of penile or perineal trauma. The case is reported of a patient with a more than 2-week history of priapism who was successfully treated by selective arterial embolization, with maintenance of potency.

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Fetal calf serum is a well known source of bovine beta2-microglobulin (beta2m) which can exchange with endogenous beta2m from, as well as promote peptide binding to, class I major histocompatibility (MHC I) molecules on cells cultured in vitro. Recombinant bovine beta2m was expressed and purified for direct functional comparison to human and murine beta2m for interactions with murine MHC I molecules H-2Kb, Db, Kd, Ld, and Dd. Bovine and human beta2m were equivalent in stabilizing MHC I heavy chains and facilitating peptide loading, suggesting similar affinities for murine MHC I heavy chains. The activity of murine beta2m was significantly weaker, consistent with previous work that demonstrated the lower affinity of murine human beta2m for murine heavy chains compared to human beta2m. Analysis of bovine beta2m in fetal calf serum revealed ten-fold higher concentrations than in adult bovine serum, levels shown to significantly affect MHC I stability and peptide loading. The ramifications for the study of MHC I molecules from cells in culture and the evolutionary implications of the higher affinity interactions of human and bovine beta2m are discussed.

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The bone of advanced teleost fishes such as those of the family Sparidae is said to lack osteocytes or to be acellular. Acellularity has been determined by apparent lack of osteocyte lacunae. This study questions the validity of this criterion. Scanning electron and light microscopy of paraffin and resin sections were used to show that the sides of sea bream mandibles consist of laminar parallel-fibred bone that we call tubular bone, because it contains tubules, and localised regions of Sharpey fibre bone. Osteocytes lie along the walls of tubules that also contain collagen fibril bundles (T-fibres), or in the lumens of tubules that do not contain T-fibres. We show that the osteocytes are derived from osteoblasts. The T-fibre system is different from other fibre systems that have been described. The tubules enclose wide T-fibres (lenticular in cross-section, maximum width about 8 microns) that taper at their ends and continue as thin T-fibres (round in cross-section, about 2 microns wide). The T-fibres originate in the periosteum. In mature tubular bone, spaces of increasing size develop around the osteocytes. Osteocytes are released from the bone matrix and become postosteocytes or bone-lining cells. Secondary bone lines the largest spaces. In Sharpey fibre bone, small osteocytes in small lacunae (about 2 microns wide) are found in columns parallel to the Sharpey fibres. Large osteocytes are found in large round spaces and are much larger than comparable osteocytes in lacunae in the bone of the salmon Salmo salar. We conclude that an absence of visible or conventional osteocyte lacunae does not mean that the cells themselves are absent. There are cells and two types of collagen fibre bundle in the tubules. The cells are osteocytes derived from osteoblasts, and these osteocytes apparently resorb bone with the result that large amounts of bone are destroyed. "Acellular" tubular and Sharpey fibre bone are types of cellular bone that differ from each other and from conventional cellular bone.

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Concentrations of fatty acids (FA) in prostatic tissue of patients with either benign or malignant prostatic disease have previously been shown to be significantly different. In particular, there was a significant reduction in arachidonic acid (AA, C20:4n-6) and docosapentaenoic acid (DPA, C22:5n-6) concentrations in malignant prostatic tissue (PCa) phospholipids (PL). It was suggested that the decreased AA concentration in PCa may be due to its increased metabolism via the cyclooxygenase (CO) and/or lipoxygenase (LO) pathways to produce eicosanoids such as prostaglandins (PGs) and/or leukotrienes (LTs) rather than an impairment in desaturase activity in situ. The eicosanoid production in benign prostatic tissue (BPH) and PCa was determined using [3H]AA. The only eicosanoid produced in significant amounts by either tissue was PGE2 and PCa converted radiolabelled AA to PGE2 at an almost 10-fold higher rate than BPH. PGE2 production from [3H]AA by PCa was investigated in the presence of oleic acid (OA, C18:1n-9), eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3), dihomo-gamma-linolenic acid (DGLA, C20:3n-6), eicosatetraynoic acid (ETYA) and ketoprofen (KPN) respectively. OA was found to be the most effective inhibitor of PGE2 production by PCa compared with DHA, EPA, ETYA and KPN, while DGLA was the least effective. Diacylglycerol (DAG) formation from labelled AA by PCa was about 4-fold greater than in BPH. Such high levels of DAG may be a means of promoting tumorigenesis through activation of protein kinase C as found with phorbol esters which can be regarded as DAG analogues.

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Scanning electron and light microscopy were used to show that the pedicels of fish teeth (the so-called "bones of attachment") consist of three types of dentine that lie concentrically around a pulp cavity lined with typical odontoblasts with cytoplasmic processes in dentinal tubules. Circumpulpal canalar dentine forms on a thin layer of orthodentine that is encased in mantle dentine. Canalar dentine is a new name given to a dentine that is similar to vasodentine in canal arrangement, but not apparently in canal content. An inner series of wide, radial canals and an outer series of highly-branched thin canals of two diameters are inhabited by a population of cells, the osteodentocytes, and collagen fibril bundles. The flat, oval osteodentocytes appear to be quiescent cells, lying on the sides of the tubules and covered by a sheath. Plump, intensely metachromatic osteodentocytes appear to be more synthetically active. The canals and the osteodentocytes originate from blood capillaries enclosed in the predentine during dentinogenesis. New teeth begin within the small cavities present in spongy bone that were enlarged by multinucleated osteoclasts during tooth growth. Pedicel formation is initiated by the extension of the crown mantle dentine, forming the outer layer of the crimped ligament and outlining the future length and curvature of the pedicel. Central and inner ligament zones are subsequently formed as orthodentine is secreted in both crown and pedicel, and canalar dentine in the pedicel. Spongy bone osteogenesis begins during stage 1 of pedicel formation with the aggregation of osteoblasts and blood capillaries in the bone cavities and in the dermis between the pedicels. Loose fibrillar osteoid condenses into incomplete thin trabeculae bordered by intensely metachromatic osteoblasts. Osteoblasts become enclosed in the developing trabeculae that thicken to give mature spongy bone with osteocytes throughout. We conclude that the pedicels are the true bases of teeth, that the dental ridge is formed from pedicels and spongy bone, and that sea bream spongy bone is cellular. The term "bone of attachment" is inappropriate for the pedicel. It can be used for the spongy bone between the compact bone of the jaw and between adjacent pedicel.

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There is increasing evidence that essential fatty acids (EFA) may have a role to play in the aetiology of some types of cancer although their precise mode of action is unknown. Differences in the metabolism of EFA between patients with benign or malignant prostatic disease may help to elucidate their role in the latter. We have, therefore, measured the concentration of the essential fatty acids, and their metabolites, in the phospholipid fractions of both plasma and tissue, in patients with either benign or malignant prostatic disease. Comparison of the median concentration of fatty acids in each group (n = 10) revealed significant differences between them. The phospholipid component of total lipid was greater in malignant (P less than 0.04, unpaired t-test) than in benign tissue. The concentrations of linoleic acid (LA) and di-homo gamma linolenic acid (DGLA) in plasma and tissue were not different between the two groups of patients, but a significant reduction in arachidonic acid (ARA) (P less than 0.002, Mann-Whitney U-test) and docosapentaenoic acid (DPA) (P = 0.009) concentrations was observed in malignant tissue as compared to benign. Patients with malignant prostatic disease also had a significantly higher concentration of oleic acid in phospholipids from both plasma and prostatic tissue. The stearic to oleic acid ratio was similar in plasma but was significantly reduced in malignant tissue (P = 0.006). We suggest that the decreased arachidonic acid concentration in malignant tissue may be due to its increased metabolism, via the lipoxygenase and cyclooxygenase pathways to produce higher concentrations of eicosanoids, rather than an impairment in desaturase activity in situ.

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We have examined the composition of the essential fatty acids in the plasma phospholipid fractions of 98 patients with histologically proven bladder cancer. These patients were attending hospital for regular follow-up by check cystoscopy. Patients were divided into two groups, depending on the cystoscopic findings, of either active (tumour recurrence seen) or inactive (no evidence of tumour recurrence) disease. Compared with a normal population, the plasma levels of most of the fatty acids, including arachidonic acid, were significantly lower in the 98 cancer patients (P less than 0.001, t-test). We were unable, however, to demonstrate any significant differences (Mann-Whitney U-test) between the active and inactive disease groups. Plasma levels of the essential fatty acids are abnormal in patients with bladder cancer; they do not help, however, to distinguish those patients with active disease from those with inactive disease. This may arise because the deficit in essential fatty acids we have demonstrated is a predisposing factor for the development of bladder cancer rather than a metabolic consequence of the tumour. Further studies are needed to establish the possible clinical role of measurement of essential fatty acids in patients with bladder carcinoma.

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Mutants that fail to express the B2mb allele can be readily isolated from a B2ma/b heterozygous cell line called R8 by a single step immunoselection protocol using a mAb against beta 2 microglobulin protein in the presence of complement. We present data that demonstrate that the mutants preexist the selection and arise at a rate of about 10(-6)/cell per generation. Southern blot analyses suggest that the mutants have lost the B2mb gene and the linked allele at the Emv-15 proviral integration site telomeric to the B2m locus. Surprisingly, the deletion of the first exon of the B2mb gene that is observed in other cell lines is not found in R8. Possible reasons for this observation are discussed.

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Immunohistochemical methods have been used to study the relationship between epidermal growth factor receptor (EGF-R), T-lymphocyte infiltrate, interleukin-2 receptor (IL-2R) expression and the degree of cellular proliferation using the monoclonal antibody Ki-67. EGF-R was detected in only 2 out of the 19 malignant biopsies, but was present in the benign elements of all twelve of the heterogeneous biopsies examined. The level of immune response, as indicated by the percentage of T cells expressing the IL-2R, did not correlate with the expression of the nuclear proliferation antigen determined by Ki-67 monoclonal antibody staining intensity. This study fails to show a statistically significant correlation between the expression of EGF-R or nuclear proliferation antigen and the degree of the cell mediated immune response to the tumour.

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