Nanos3 of the frog Rana rugosa: Molecular cloning and characterization

Nanos is expressed in the primordial germ cells (PGCs) and also the germ cells of a variety of organisms as diverse as Drosophila, medaka fish, Xenopus and mouse. In Nanos3-deficient mice, PGCs fail to incorporate into the gonad and the size of the testis and ovary is thereby dramatically reduced. To elucidate the role of Nanos in an amphibian species, we cloned Nanos3 cDNA from the testis of the R. rugosa frog. RT-PCR analysis showed strong expression of Nanos3 mRNA in the testis of adult R. rugosa frogs, but expression was not sexually dimorphic during gonadal differentiation. In Nanos3-knockdown tadpoles produced by the CRISPR/Cas9 system, the number of germ cells decreased dramatically in the gonads of both male and female tadpoles before sex determination and thereafter. This was confirmed by three dimensional imaging of wild-type and Nanos3 knockdown gonads using serial sections immunostained for Vasa, a marker specific to germ cells. Taken together, these results suggest that Nanos3 protein function is conserved between R. rugosa and mouse.

Cutaneous Angioleiomyoma - A Rare Cause of Posterior Heel Pain: A Case Report

Heel pain is a common presentation in outpatient clinics. Here, we report a 69-year-old woman who complaint about a painful nodule on her left posterior heel. There was no history of trauma. The lesion developed during ten weeks without any bleeding or ulceration. On examination, we observed a subcutaneous firm nodule of about 1 cm in diameter. The lesion was hypoechoic in diagnostic sonography suggesting a fibromatous tumour, which was removed surgically. Histologic investigations confirmed the diagnosis of cutaneous angioleiomyoma. The occurrence of this benign tumour on the heel is quite uncommon but obvious a possible cause for heel pain. During follow-up, no recurrence was observed.

[Features of cytotrophoblast invasion in complete placenta previa and increta]

AIM

to investigate the characteristics of cytotrophoblast invasion in complete placenta previa and increta.

MATERIAL AND METHODS

Three groups of placentas and amputated uteri were examined. These were: 1) 10 placentas at 20-22 weeks' gestation after drug-induced abortion; 2) 4 uteri with typical placentation at 34-36 weeks and wall ruptures; 3) 12 uteri with ultrasound-confirmed complete placenta previa and subsequent hysterectomy (at 34-36 weeks.) due to massive bleeding. In all cases, the sections were stained with hematoxylin and eosin, azan by the Mallory's method; immunovisualization of invasive cells with the marker cytokeratin 8 was also used. In Groups 2 and 3, the uterine distribution density of invasive cells was compared in a standard slice area (×200) separately, within the endometrium and myometrium.

RESULTS

Complete placenta previa was found to have the following characteristics: 1) all the uteri exhibited focal or diffuse friable, or thick scars after cesarean section; 2) multiple active anchor villi with villous cytotrophoblast layers, which were characteristic of Group 1 placentas and absent in the uteri women of Group 2; 3) bays diagnosed in the basal endometrium with ingrown villi (placenta increta); 4) a morphometrically significant increase in the distribution density of interstitial cytotrophoblast in the endometrium and only a similar trend in the myometrium. Invasive cells did not penetrate into the area of scars. Failure of the second wave of cytotrophoblast invasion was confirmed by incomplete gestational restructuring and partial obliteration of the myometrial radial arteries.

CONCLUSION

Real risks for severe clinical forms of abnormal placentation declare more stringent indications for surgical delivery.

Interstitial photodynamic therapy and glioblastoma: Light fractionation in a preclinical model

BACKGROUND

Glioblastoma is a high-grade cerebral tumor with local recurrence and poor outcome. Photodynamic therapy (PDT) is a localized treatment based on the light activation of a photosensitizer (PS) in the presence of oxygen, which results in the formation of cytotoxic species. The delivery of fractionated light may enhance treatment efficacy by reoxygenating tissues.

OBJECTIVE

To evaluate the efficiency of two light-fractionation schemes using immunohistological data.

MATERIALS AND METHODS

Human U87 cells were grafted into the right putamen of 39 nude rats. After PS precursor intake (5-ALA), an optic fiber was introduced into the tumor. The rats were randomly divided into three groups: without light, with light split into 2 fractions and with light split into 5 fractions. Treatment effects were assessed using brain immunohistology.

RESULTS

Fractionated treatments induced intratumoral necrosis (P < 0.001) and peritumoral edema (P = 0.009) associated with a macrophagic infiltration (P = 0.006). The ratio of apoptotic cells was higher in the 5-fraction group than in either the sham (P = 0.024) or 2-fraction group (P = 0.01). Peripheral vascularization increased after treatment (P = 0.017), and these likely new vessels were more frequently observed in the 5-fraction group (P = 0.028).

CONCLUSION

Interstitial PDT with fractionated light resulted in specific tumoral lesions. The 5-fraction scheme induced more apoptosis but led to greater peripheral neovascularization. Lasers Surg. Med. 49:506-515, 2017. © 2016 Wiley Periodicals, Inc.

Verification of the Cross Immunoreactivity of A60, a Mouse Monoclonal Antibody against Neuronal Nuclear Protein

A60, the mouse monoclonal antibody against the neuronal nuclear protein (NeuN), is the most widely used neuronal marker in neuroscience research and neuropathological assays. Previous studies identified fragments of A60-immunoprecipitated protein as Synapsin I (Syn I), suggesting the antibody will demonstrate cross immunoreactivity. However, the likelihood of cross reactivity has never been verified by immunohistochemical techniques. Using our established tissue processing and immunofluorescent staining protocols, we found that A60 consistently labeled mossy fiber terminals in hippocampal area CA3. These A60-positive mossy fiber terminals could also be labeled by Syn I antibody. After treating brain slices with saponin in order to better preserve various membrane and/or vesicular proteins for immunostaining, we observed that A60 could also label additional synapses in various brain areas. Therefore, we used A60 together with a rabbit monoclonal NeuN antibody to confirm the existence of this cross reactivity. We showed that the putative band positive for A60 and Syn I could not be detected by the rabbit anti-NeuN in Western blotting. As efficient as Millipore A60 to recognize neuronal nuclei, the rabbit NeuN antibody demonstrated no labeling of synaptic structures in immunofluorescent staining. The present study successfully verified the cross reactivity present in immunohistochemistry, cautioning that A60 may not be the ideal biomarker to verify neuronal identity due to its cross immunoreactivity. In contrast, the rabbit monoclonal NeuN antibody used in this study may be a better candidate to substitute for A60.

Immunohistochemical localisation and effect of matrix metalloproteinases and their inhibitors on canine spontaneous periodontitis

Periodontitis is commonly observed in dogs. In human medicine, it is well documented that matrix metalloproteinases (MMPs) are involved in the destruction of the periodontium. Therefore, the aim of this prospective study was to investigate the impact of MMPs and their inhibitors, the TIMPs (tissue inhibitors of metalloproteinases), on canine periodontitis. The oral cavities of 57 dogs were examined clinically and radiologically. Gingival biopsies were obtained from the examined dogs and histologically analysed via haematoxylin and eosin stained sections. Immunohistological detection of MMP-2, MMP-3, MMP-8 and MMP-9 as well as TIMP-1 and TIMP-2 was performed by the avidin-biotin peroxidase complex technique. All sections were evaluated by light microscopy. Statistically significant positive correlations were detected between the histologically verified degree of inflammation and the expression of MMP-2, MMP-3, MMP-8 and MMP-9 as well as between changes in collagen fibre content and the occurrence of MMP-2, MMP-8 and MMP-9. Concerning TIMP-1 and TIMP-2, non-significant, generally negative correlations were observed. In summary, in canine periodontitis, an increased expression of the above mentioned MMPs and a tendentially decreased expression of TIMPs are present. In conclusion, in canine periodontitis, a MMP-TIMP imbalance is suggestive of contributing to the destruction of the periodontium.

Extracellular matrix-based intracortical microelectrodes: Toward a microfabricated neural interface based on natural materials

Extracellular matrix (ECM)-based implantable neural electrodes (NEs) were achieved using a microfabrication strategy on natural-substrate-based organic materials. The ECM-based design minimized the introduction of non-natural products into the brain. Further, it rendered the implants sufficiently rigid for penetration into the target brain region and allowed them subsequently to soften to match the elastic modulus of brain tissue upon exposure to physiological conditions, thereby reducing inflammatory strain fields in the tissue. Preliminary studies suggested that ECM-NEs produce a reduced inflammatory response compared with inorganic rigid and flexible approaches. In vivo intracortical recordings from the rat motor cortex illustrate one mode of use for these ECM-NEs.

Histopathology of rhinophyma - a clinical-histopathologic correlation

BACKGROUND

Whereas early rhinophyma is histopathologically thought to resemble fully developed rosacea, a fibromatous variant has previously been described for severe rhinophyma. In terms of clinical characteristics, recently a new Rhinophyma Severity Index (RHISI) was introduced.

METHODS

We studied 24 patients who had been treated with wide shave excisions for rhinophyma. Specimens were stained with hematoxylin-eosin, periodic acid-Schiff reaction and a panel of immunohistochemical stains and observed for any correlation between clinical severity and histopathologic features as well as for predictive markers of clinical recurrence.

RESULTS

There were no significant histopathologic differences between the groups reflecting the different clinical expressions. From a histopathologic perspective, clinically severe forms did not show with exclusive fibrotic changes. Further, there was no histopathologic marker predicting the clinical course or possible recurrence of the disease after surgical treatment. Only the clinical pre-operative RHISI score correlated with the postoperative outcome, with a high pre-operative RHISI being a risk factor for recurrence.

CONCLUSION

Histopathologic features do not correlate with the clinical expression of rhinophyma. An exclusively 'fibrotic' rhinophyma form does not appear to exist and could possibly be the result of sampling error based on small biopsies studied.

Heterogeneity of stromal cells in the human splenic white pulp. Fibroblastic reticulum cells, follicular dendritic cells and a third superficial stromal cell type

At least three phenotypically and morphologically distinguishable types of branched stromal cells are revealed in the human splenic white pulp by subtractive immunohistological double-staining. CD271 is expressed in fibroblastic reticulum cells of T-cell zones and in follicular dendritic cells of follicles. In addition, there is a third CD2711- and CD271+/) stromal cell population surrounding T-cell zones and follicles. At the surface of follicles the third population consists of individually variable partially overlapping shells of stromal cells exhibiting CD90 (Thy-1), MAdCAM-1, CD105 (endoglin), CD141 (thrombomodulin) and smooth muscle α-actin (SMA) with expression of CD90 characterizing the broadest shell and SMA the smallest. In addition, CXCL12, CXCL13 and CCL21 are also present in third-population stromal cells and/or along fibres. Not only CD27+ and switched B lymphocytes, but also scattered IgD++ B lymphocytes and variable numbers of CD4+ T lymphocytes often occur close to the third stromal cell population or one of its subpopulations at the surface of the follicles. In contrast to human lymph nodes, neither podoplanin nor RANKL (CD254) were detected in adult human splenic white pulp stromal cells. The superficial stromal cells of the human splenic white pulp belong to a widespread cell type, which is also found at the surface of red pulp arterioles surrounded by a mixed T-cell/B-cell population. Superficial white pulp stromal cells differ from fibroblastic reticulum cells and follicular dendritic cells not only in humans, but apparently also in mice and perhaps in rats. However, the phenotype of white pulp stromal cells is species-specific and more heterogeneous than described so far.

Salivary duct carcinoma of the parotid gland: A case report and review of the literature

Salivary duct carcinoma (SDC) is a rare and aggressive parotid malignancy that most commonly affects males in the fifth and sixth decades of life. Histopathology specimens obtained from SDC patients demonstrate a resemblance to ductal carcinoma of the breast. Therefore, to distinguish SDC from breast ductal carcinoma, several immunohistochemical markers exist that may enable surgeons to make an accurate diagnosis. In this study, the case of a 54-year-old male with salivary duct carcinoma of the right parotid gland is presented. The results of the present case study revealed that the SDC sample was positive for the expression of human epidermal growth factor 2 (Her-2), cytokeratin (CK) 8/CK 18, p63, high molecular weight CK and calponin, and negative for expression of the estrogen receptor and progesterone receptor. Based on the result, an ipsilateral selective neck dissection followed by adjuvant post-operative radiation therapy was suitable at the primary treatment stage. At one year of follow-up, the patient was alive and free of recurrence. In advanced cases of SDC, treatment with anti-HER-2 monoclonal antibodies, such as trastuzumab, is recommended.

A survey of Sertoli cell differentiation in men after gonadotropin suppression and in testicular cancer

It is widely held that the somatic cell population that is responsible for sperm development and output (Sertoli cells) is terminally differentiated and unmodifiable in adults. It is postulated, with little evidence, that Sertoli cells are not terminally differentiated in some phenotypes of infertility and testicular cancer. This study sought to compare markers of Sertoli cell differentiation in normospermic men, oligospermic men (undergoing gonadotropin suppression) and testicular carcinoma in situ (CIS) and seminoma samples. Confocal microscopy was used to assess the expression of markers of proliferation (PCNA and Ki67) and functional differentiation (androgen receptor). As additional markers of differentiation, the organization of Sertoli cell tight junction and associated proteins were assessed in specimens with carcinoma in situ. In normal men, Sertoli cells exhibited a differentiated phenotype (i.e., PCNA and Ki67 negative, androgen 40 receptor positive). However, after long-term gonadotropin suppression, 1.7 ± 0.6% of Sertoli cells exhibited PCNA reactivity associated with a diminished immunoreactivity in androgen receptor, suggesting an undifferentiated phenotype. Ki67-positive Sertoli cells were also observed. PCNA-positive Sertoli cells were never observed in tubules with carcinoma in situ, and only rarely observed adjacent to seminoma. Tight junction protein localization (claudin 11, JAM-A and ZO-1) was altered in CIS, with a reduction in JAM-A reactivity in Sertoli cells from tubules with CIS and the emergence of strong JAM-A reactivity in seminoma. These findings indicate that adult human Sertoli cells exhibit characteristics of an undifferentiated state in oligospermic men and patients with CIS and seminoma in the presence of germ cell neoplasia.

Activation of lateral hypothalamus-projecting parabrachial neurons by intraorally delivered gustatory stimuli

The present study investigated a subpopulation of neurons in the mouse parabrachial nucleus (PbN), a gustatory and visceral relay area in the brainstem, that project to the lateral hypothalamus (LH). We made injections of the retrograde tracer Fluorogold (FG) into LH, resulting in fluorescent labeling of neurons located in different regions of the PbN. Mice were stimulated through an intraoral cannula with one of seven different taste stimuli, and PbN sections were processed for immunohistochemical detection of the immediate early gene c-Fos, which labels activated neurons. LH projection neurons were found in all PbN subnuclei, but in greater concentration in lateral subnuclei, including the dorsal lateral subnucleus (dl). Fos-like immunoreactivity (FLI) was observed in the PbN in a stimulus-dependent pattern, with the greatest differentiation between intraoral stimulation with sweet (0.5 M sucrose) and bitter (0.003 M quinine) compounds. In particular, sweet and umami-tasting stimuli evoked robust FLI in cells in the dl, whereas quinine evoked almost no FLI in cells in this subnucleus. Double-labeled cells were also found in the greatest quantity in the dl. Overall, these results support the hypothesis that the dl contains direct a projection to the LH that is activated preferentially by appetitive compounds; this projection may be mediated by taste and/or postingestive mechanisms.

[Peripheral keratinizing ameloblastoma in a dwarf rabbit (Oryctolagus cuniculus f. dom.)]

A 3.5-year-old, male, neutered dwarf rabbit was presented with a history of a fast-growing gingival mass at the maxilla. The neoplasm was surgically completely excised. Histopathologically, an expansively growing, multilobulated, partially cystic, peripheral, keratinizing ameloblastoma was diagnosed. The immunohistochemical phenotyping of the tumour cells resulted in cytoplasmic labelling with various pan-cytokeratin antibodies. The cytokeratins 5/6, 7, 10 and 14 were expressed variably. Cytokeratin 20 was not detected. Vimentin was expressed in the cytoplasm of mesenchymal cells of the tumour stroma. In addition, in the nuclei of approximately 10% of the tumour cells the protein of the tumour suppressor gene p53 was expressed while in approximately 5% the proliferation marker Ki67 was expressed. Odontogenic tumours should be considered as a differential diagnosis of oral masses in rabbits.

[Congenital embryonal rhabdomyosarcoma of the head in a red and white German Holstein calf]

Tumours with skeletal-muscle differentiation are rare in companion animals. They are differentiated into benign rhabdomyomas and malignant rhabdomyosarcomas. A female German Holstein calf displayed a congenital, spherical, subcutaneous mass at the lateral side of the head. Histology revealed an encapsulated, expansile, highly cellular mass consisting of a reticular meshwork of moderately pleomorphic, small spindle-shaped to round cells within a fibrovascular to myxoid stroma as well as multifocal, large, blunt, multinucleated myotube-like cells (strap cells). Electron microscopy demonstrated characteristic cytoplasmic bundles of myofilaments and Z-stripes within the strap cells. Immunoreactivity for vimentin was observed in the small spindle-shaped cells and for desmin in the strap cells. The results are consistent with the spectrum of findings characteristic for a bovine congenital embryonal rhabdomyosarcoma.

Towards understanding region-specificity of triplet repeat diseases: coupled immunohistology and mass spectrometry imaging

Many trinucleotide repeat disorders exhibit region-specific toxicity within tissues, the basis of which cannot be explained by traditional methods. For example, in Huntington's Disease (HD), the toxic disease-causing protein is ubiquitously expressed. However, only the medium spiny neurons in the striatum are initially targeted for death. Many changes are likely to initiate in these cells at an intracellular and microstructural level long before there is a measureable phenotype, but why some regions of the brain are more susceptible to death is unknown. This chapter describes a method to detect functional changes among brain regions and cell types, and link them directly with region-specific physiology. Due to the neurodegeneration that accompanies many triplet repeat disorders, we focus on the brain, although the methods described in this chapter can be translated to other tissue types. We integrate immunohistology and traditional mass spectrometry with a novel mass spectrometry imaging technique, called nanostructure initiated mass spectrometry (NIMS). When used together, these tools offer unique insights into region-specific physiology of the brain, and a basis for understanding the region-specific toxicity associated with triplet repeat disorders.

Squamous cell carcinoma originated from an epidermal cyst

Epidermal cyst (EC) of the skin is a very common condition. Squamous cell carcinoma (SCC) very infrequently arises from EC. A 76-year-old Japanese woman was admitted to our hospital because of multiple papules in the nose and nasal cavity. The clinical diagnosis was sebaceous hyperplasia. An excisional biopsy was obtained from one papule. Histologically, the papule showed an EC. The EC communicated with the epidermis. Islands of atypical cells with hyperchromatic nuclei and infrequent pearl formation were recognized around and adjacent to EC. No connections were seen between the atypical cell islands and epidermis. The atypical cells had hyperchromatic nuclei and nucleoli. Mitotic figures and keratinous pearls were scattered. The HE diagnosis was probable SCC probably arising from EC. Immunohistochemically, the atypical cells were positive for pancytokeratin AE1/3, cytokeratin (CK) 5/6, CK14, CK18, CK 34BE14, EMA, p53, Ki-67 (labeling 90%), and p63. They were negative for pancytokeratin CAM5.2, CK7, CK8, CK19, CK20, vimentin, S100 protein, HMB45, synaptophysin, and CD56. CD68 was positive in histiocytes and giant cells in the foreign body reaction. The EC showed the same immunoprofile as the SCC, except for negative p53 and low Ki-67 labeling in the EC. The histological and immunohistochemical diagnosis was definite SCC arising from EC.

Gluten affects epithelial differentiation-associated genes in small intestinal mucosa of coeliac patients

In coeliac disease gluten induces an immunological reaction in genetically susceptible patients, and influences on epithelial cell proliferation and differentiation in the small-bowel mucosa. Our aim was to find novel genes which operate similarly in epithelial proliferation and differentiation in an epithelial cell differentiation model and in coeliac disease patient small-bowel mucosal biopsy samples. The combination of cDNA microarray data originating from a three-dimensional T84 epithelial cell differentiation model and small-bowel mucosal biopsy samples from untreated and treated coeliac disease patients and healthy controls resulted in 30 genes whose mRNA expression was similarly affected. Nine of 30 were located directly or indirectly in the receptor tyrosine kinase pathway starting from the epithelial growth factor receptor. Removal of gluten from the diet resulted in a reversion in the expression of 29 of the 30 genes in the small-bowel mucosal biopsy samples. Further characterization by blotting and labelling revealed increased epidermal growth factor receptor and beta-catenin protein expression in the small-bowel mucosal epithelium in untreated coeliac disease patients compared to healthy controls and treated coeliac patients. We found 30 genes whose mRNA expression was affected similarly in the epithelial cell differentiation model and in the coeliac disease patient small-bowel mucosal biopsy samples. In particular, those genes involved in the epithelial growth factor-mediated signalling pathways may be involved in epithelial cell differentiation and coeliac disease pathogenesis. The epithelial cell differentiation model is a useful tool for studying gene expression changes in the crypt-villus axis.

Smooth muscle cell proliferation but not neointimal formation is dependent on alloantibody in a murine model of intimal hyperplasia

Transplant coronary artery disease is the pre-eminent cause of late cardiac allograft failure. It is primarily characterized by a concentric intimal hyperplasia, which we designate transplant intimal hyperplasia (TIH). Although the pathogenesis of TIH is predominately immune driven, the specific role of alloantibodies in the disease process remains undefined. In this study we investigated the contribution of alloantibodies to the development of TIH in a murine model. Orthotopic, carotid artery transplantation was performed between B10A(2R) (H-2(h2)) donor mice and B-cell deficient muMT(-/-) knockout or wild-type C57BL/6 (H-2(b)) recipients in the absence of immunosuppression. Grafts were harvested at 35 days and subjected to planimetry and immunohistochemistry. Alloantibodies were detectable in wild-type recipients within 7 days of transplantation and recipients developed marked TIH at 35 days. Allografts harvested from B-cell deficient recipient mice also developed TIH, which was comparable in severity with wild-type recipients. However, whereas allografts from wild-type recipients showed marked intimal smooth muscle cell (SMC) proliferation, the neointima in B-cell deficient recipients lacked SMCs. Post-transplantation administration of anti-donor serum to muMT(-/-) recipients restored neointimal SMC population but did not influence the severity of TIH. Significant neointimal formation occurs in the absence of alloantibodies but lacks a SMC component. Therefore, SMC migration and proliferation is antibody dependent.

Immunohistological examination of open sacroiliac biopsies of patients with ankylosing spondylitis: detection of tumour necrosis factor alpha in two patients with early disease and transforming growth factor beta in three more advanced cases

OBJECTIVE

To characterise the immunohistological features of sacroiliitis in ankylosing spondylitis (AS) at different disease stages.

METHODS

Biopsy samples from sacroiliac joints (SIJs) of five patients with AS, two with early, three with advanced changes and samples from age matched controls from one necropsy SIJ and two iliac bone marrow (BM) biopsies were studied. Paraffin sections were immunostained in triplicate for T cells (CD3, CD8), macrophages (CD68), and the cytokines tumour necrosis factor alpha (TNFalpha), interferon gamma, interleukin (IL) 1beta, IL6, IL10, and transforming growth factor beta1 (TGFbeta1). Stained cells were counted over one entire high power field (x400) per section in BM, cartilage, and other connective tissue (CT). Results are the mean of three sections.

RESULTS

CD3+ T cells were numerous in the BM of early AS, and in the CT of one patient with early and one with late AS, with variable proportions of CD8+ T cells. All patients with AS had more CD68+ macrophages than controls in BM and CT; in cartilage, one patient with early and one with late AS had increased CD68+ cells, some being osteoclasts. The patient with very early AS had large numbers of TNFalpha cells in the three tissular areas; for the other patient with early disease they were found only in CT and cartilage. IL6 was seen in 4/4 patients with AS in most areas. Patients with early disease had more T cells, TNFalpha, and IL6, and patients with advanced AS more TGFbeta1.

CONCLUSION

The immunohistological findings of a limited sample suggest a role for BM in sacroiliitis, for TNFalpha and IL6 in early, active lesions, and for TGFbeta1 at the time of secondary cartilage and bone proliferation.

Strain-specific differences in perivascular inflammation in lungs in two murine models of allergic airway inflammation

Histological data show perivascular recruitment of inflammatory cells in lung inflammation. However, the process of perivascular inflammation is yet-to-be characterized in any systematic manner at cell and molecular levels. Therefore, we investigated impact of genetic background on perivascular inflammation in acute or chronic airway inflammation in different strains of mice. Further, to address molecular mechanisms of perivascular inflammation, we examined immunohistochemical expression of vascular adhesion protein-1 (VAP-1) in chronic airway inflammation. Histological scoring revealed time and strain specific differences in perivascular recruitment of inflammatory cells in chronic and acute airway inflammation (P < 0.05). The data show that A/J strain is significantly more susceptible for perivascular inflammation followed by BALB/c and C57BL/6, while C3H/HeJ strain showed no perivascular accumulation of inflammatory cells. Of the two strains examined for perivascular inflammation in acute airway inflammation, BALB/c showed more accumulation of inflammatory cells compared to C57BL/c. VAP-1 expression occurred in the endothelium of pulmonary arteries but not in alveolar septa or airways in the control as well as challenged mice. In the inflamed lungs from A/J mice, the VAP-1 staining in pulmonary arteries was more intense compared to the other strains. VAP-1 staining was generally observed throughout the pulmonary arterial wall in chronic lung inflammation. These data show that periarterial inflammation is influenced by the genetic background, and may be partially regulated by VAP-1.

Lack of evidence for an association of Epstein-Barr virus infection with breast carcinoma

BACKGROUND

Epstein-Barr virus (EBV) is a ubiquitous human gamma-herpes virus infecting more than 90% of the population worldwide. EBV is associated with certain malignancies (e.g. Burkitt lymphoma, Hodgkin lymphoma and nasopharyngeal carcinoma). Recent studies have raised the possibility that EBV may also be involved in the pathogenesis of breast carcinoma, the most common carcinoma of females. If substantiated, this finding would have major implications regarding prevention and therapy of the disease. The studies published so far have employed diverse methods, however, and the results have been controversial.

METHODS

Using the EBV DNA PCR, EBV DNA in situ hybridisation and in situ hybridisation for the detection of the EBV-encoded RNAs, and using immunohistochemistry for the demonstration of the EBV-encoded nuclear antigen 1, we have studied a series of 59 invasive breast carcinomas for evidence of EBV infection.

RESULTS

EBV-encoded RNA-specific in situ hybridisation and EBV-encoded nuclear antigen 1 immunohistochemistry were negative in all cases. Using the PCR, EBV DNA was detected in four out of 59 cases. These cases were further studied by EBV DNA in situ hybridisation, showing an absence of viral DNA from the tumour cells.

CONCLUSION

These results indicate that breast carcinoma is not an EBV-associated tumour.

Generation of human anti-MUC3 IgG antibodies after in vitro immunization of naive peripheral blood B-lymphocytes

It has been demonstrated that IgG antibodies can be generated to self-antigen peptides as well as against viral antigens by an antigen-specific in vitro immunization system of resting human peripheral B-lymphocytes. Using a synthetic peptide from the consensus variable tandem-repeat region of the MUC3 mucin (TSSITTTGTTSHSTPSP) as the B cell epitope, we immunized blood donor B-lymphocytes in vitro and tested for MUC3-specific antibodies by ELISA. After the primary activation step all antibodies were IgM. At the end of the secondary immunization step we obtained 1.8% (21/1138) of the cultures with IgG-switched antibodies. In a competitive inhibition ELISA using the MUC1, MUC2, MUC3, MUC4 and PIP2 peptides, only one culture (F8.1) gave satisfactory specific inhibition. Using this antibody in fluorometric studies, it stained cells from two colon carcinoma cell lines predominantly in the cytoplasm, whereas those from a breast cancer cell line stained predominantly the cell surface. In a preliminary immunohistological evaluation with formalin-fixed sections, the antibody appeared to moderately stain colon sections, but not breast sections or lymph node. This method of in vitro immunization may be a useful tool in generating IgG antibodies specific to self-antigens and could find applications in tumour targeting and immunotherapy.

Immunohistological studies of metabotropic glutamate receptor subtype 6-deficient mice show no abnormality of retinal cell organization and ganglion cell maturation

Immature retinal ganglion cells (RGCs) initially show a multistratified dendritic pattern, and, during the postnatal period, these dendrites gradually monostratify into ON and OFF sublaminae. The selective agonist of group III metabotropic glutamate receptors (mGluR), L-2-amino-4-phosphonobutyrate (L-AP-4), hyperpolarizes ON bipolar cells and reduces glutamate release. On the basis of L-AP-4-evoked inhibitory effects on ON-OFF segregation of developing RGCs, it has been hypothesized that glutamate-mediated synaptic activity is crucial for formation of the ON-OFF network. Gene-targeted ablation of mGluR6 specifically expressed in ON bipolar cells blocks normal ON responses but has been predicted to enhance glutamate release from ON bipolar cells. The mGluR6 knock-out mouse therefore provides a unique opportunity to investigate whether glutamate release and ON responses are important factors in the development of ON-OFF segregation. The combination of several different morphological analyses indicates that ON bipolar cells, as well as several distinct amacrine cells, in mGluR6 knock-out mice are normally distributed and correctly extend their terminals to defined retinal laminae. Importantly, both alpha and delta RGCs in adult mGluR6 knock-out mice are found monostratified into cell type-specific layers. Furthermore, no difference between wild-type and mGluR6 knock-out mice is observed in the maturation and dendritic stratification of developing RGCs. Hence, despite a deficit in normal ON responses, mGluR6 deficiency causes no abnormality in the retinal cellular organization nor in the stratifications of both ON bipolar cells and developing and mature RGCs. Based on these findings, we discuss several possible mechanisms that may underlie ON-OFF segregation of RGCs.

Cellular composition, coronavirus antigen expression and production of specific antibodies in lesions in feline infectious peritonitis

Twenty-three cats with spontaneous feline infectious peritonitis (FIP) were examined by light microscopy including immunohistology and histochemistry in order to determine the cellular composition and the expression of viral antigen in lesions in FIP. Furthermore, the presence of plasma-cells producing coronavirus-specific antibodies was evaluated in situ. Macrophages and neutrophils were demonstrated by an antibody against calprotectin (leukocyte protein L1, myeloid/histiocyte antigen), neutrophils were recognized due to their chloroacetate esterase activity, and B- and T-lymphocytes were identified by antibodies against the CD3 antigen and the CD45R antigen, respectively. Expression of viral antigen was immunohistologically demonstrated by a monoclonal antibody (mAb) against coronavirus while coronavirus-specific antibodies in situ were identified by the application of feline coronavirus prior to the coronavirus antibody. Lesions were classified as diffuse alterations at serosal surfaces, granulomas with areas of necrosis, granulomas without extended necrosis, focal and perivascular lymphoplasmocytic infiltrates, and granulomatous-necrotizing vasculitis. Diffuse alterations on serosal surfaces were represented either by activated mesothelial cells with single coronavirus antigen-bearing macrophages or by layers of precipitated exudate containing single to numerous granulomas with areas of necrosis. In liver and spleen, the exudate was often underlaid by a small band of subcapsular B-cells with an occasional plasma-cell producing coronavirus-specific antibodies. In other locations, a variably broad band of B-cells and plasma-cells, often infiltrating between underlying muscle fibers, separated the exudate from the unaltered tissue. Some of these plasma-cells were positive for coronavirus-specific antibodies. In granulomas with areas of necrosis, the central necrosis was surrounded by macrophages usually expressing considerable amounts of viral antigen. Few B-cells and plasma-cells were found in the periphery. In granulomas without extended necrosis, the number of macrophages were lower. Only few macrophages expressing low amounts of viral antigen were present. B-cells and plasma-cells formed a broad rim. Few plasma-cells stained positive for coronavirus-specific antibodies. In both types of granulomas, few neutrophils were found between macrophages. Few T-cells were seen scattered throughout the lesions. Focal and perivascular lymphoplasmocytic infiltrates were mainlyseen in omentum and leptomeninx. B-cells were the predominant cells; some plasma-cells were positive for coronavirus-specific antibodies. Viral antigen was not readily detected in these alterations. Granulomatous-necrotizing vasculitis was occasionally found in kidneys and leptomeninx. It was dominated by macrophages which often stained strongly positive for coronavirus antigen. Different types of alteration were often seen in the same animal and even the same tissue. There was no obvious correlation between the cat's age, gross pathological changes, and the histological types of alteration. Single plasma-cells positive for coronavirus-specific antibodies were found around blood vessels distant from inflammatory alterations, within the lung parenchyma, as infiltrating cells in the mucosa of the small intestine, and in spleen and mesenteric lymph node. Results show that alterations in FIP are heterogeneous concerning cellular composition and expression of viral antigen. The dominance of B-cells in part of the lesions together with the presence of plasma-cells positive for coronavirus-specific antibodies indicate that these cells may play a role in the maintenance of inflammatory processes in FIP.

Subtractive isolation of phage-displayed single-chain antibodies to thymic stromal cells by using intact thymic fragments

In the murine thymus, the stroma forms microenvironments that control different steps in T cell development. To study the architecture of such microenvironments and more particularly the nature of communicative signals in lympho-stromal interaction during T cell development, we have employed the phage antibody display technology, with the specific aim of isolating thymic stromal cell-specific single-chain antibodies from a semisynthetic phage library. A subtractive approach using intact, mildly fixed thymic fragments as target tissue and lymphocytes as absorber cells generated monoclonal phages (MoPhabs) detecting subsets of murine thymic stromal cells. In the present paper we report on the reactivity of single-chain antibodies derived from three MoPhabs, TB4-4, TB4-20, and TB4-28. While TB4-4 and TB4-20 are both epithelium specific, TB4-28 detects an epitope expressed on both epithelial- and mesenchymal-derived stromal cells. TB4-4 reacts with all cortical epithelial cells and with other endoderm-derived epithelia, but this reagent leaves the majority of medullary epithelial cells unstained. In contrast, MoPhab TB4-20 detects both cortical and medullary thymic epithelial cells, as well as other endoderm- and ectoderm-derived epithelial cells. Cross-reaction of single-chain antibodies to human thymic stromal cells shows that our semisynthetic phage antibody display library, in combination with the present subtractive approach, permits detection of evolutionary conserved epitopes expressed on subsets of thymic stromal cells.