Immunoelectron microscopic analysis of Ia antigen expression in rat skin during limb allograft rejection

Using a whole-limb graft model in rats, morphologic changes and variations in the expression of Ia antigen on epidermal cells were investigated in the allografted skin during acute rejection. BN right limbs were transplanted to F344 recipients. Skin tissues were excised during acute rejection on days 1, 3, 5, 7, and 9 after the transplantation. Sections were examined for Ia antigen expression using immunohistologic techniques, and in situ quantification of Ia antigen was made using an immunogold method. Epidermal keratinocytes expressed Ia antigen before the grafts were rejected and the amount of Ia antigen expression increased and exceeded the amount of Ia antigen of Langerhans cells during the course of rejection. The progressive increase in class II antigen expression on EKs correlated with the appearance and relative accumulation of dermal lymphocytic cells. On the other hand, Ia antigen was not expressed on vascular endothelial cells during rejection. Our results suggest that the Ia-positive keratinocytes can serve as target cells in skin rejection of limb allografts. The immunogold technique we used seems most pertinent for a quantitative examination of cell-surface antigens in situ.     

Effects of erythropoietin on glial cell development; oligodendrocyte maturation and astrocyte proliferation

We investigated the effects of erythropoietin (Epo) in glial cell development, especially the maturation of late stage immature oligodendrocytes and the proliferation of astrocytes. Epo mRNA level in oligodendrocytes was much more prominent than those in neurons or astrocytes, which were the same as those in the young adult kidney, while Epo receptor (Epo-R) mRNA level were almost the same among neural cells, kidney and liver tissues. On immunohistochemical examination, Epo-R expression was also detected in O4-positive immature oligodendrocytes and glial fibrillary acidic protein positive astrocytes. These results suggested that types of both glial cells are responsive to Epo. The numbers of mature oligodendrocytes, which are characterized by myelin basic protein and process development, were increased by treatment with recombinant human Epo (rhEpo) (0.001-0.1 U/ml). The maturation of oligodendrocytes was also enhanced by coculture with astrocytes in vitro. However, when mixed cultured cells (oligodendrocytes+astrocytes) were treated with anti-Epo antibody and/or soluble Epo-R, the differentiation of oligodendrocytes was partially inhibited. Interestingly, high dose rhEpo (1, 3, 10 U/ml) markedly enhanced the proliferation of astrocytes. These results suggested that Epo not only promotes the differentiation and/or maturation in oligodendrocytes, but also enhances the proliferation of astrocytes. It is generally accepted that astrocytes produce Epo, and therefore Epo might act on astrocytes in an autocrine manner. The astrocytes stimulated with Epo may further accelerate the maturation of oligodendrocytes. These comprehensive effects of Epo might also affect the ability of oligodendrocyte lineage cells to promote myelin repair in the normal and damaged adult central nervous system.     

Transforming growth factor J3 type II receptor (TGFpRII) mutation in gastric lymphoma without mutator phenotype

A new mutation in the serine-threonine klnase domain of the transforming growth factor β type II receptor (TGFpRII) was found in a case of diffuse, B cell non-Hodgkin's lymphoma of the stomach. A mfssense mutation (ACA to GCA, Thr to Ala) was detected In exon 5, and a wild type allele was also present. This Is the first naturally occurring mutation in the klnase domain of this gene identified in human primary lymphoma. The replication error at three loci was negative, and the poly A tract of exon 3, which is frequently a target of mismatch repair genes, was intact. Malignant lymphoma of B cell origin in the stomach Is an addition to an expanding catalogue of tumors with TGFβRII alterations, and the biological sequelae of the change in the functional domain and the clinical characteristics of the patient in this study are intriguing.     

Histological grade in invasive ductal carcinoma of breast correlates with the proliferative activity evaluated by BrdU: An immunohistochemical study including correlations with p53, c-erbB-2 and estrogen receptor status

Thirty cases of invasive ductal carcinoma of the breast were classified to histological subtype according to the General Rules for Clinical and Pathological Recording of Breast Cancer of the Japanese Breast Cancer Society and histologically graded using the Nottingham method and the correlation of histology with proliferative activity was investigated using bromodeoxyuridine (BrdU). In addition, the overexpression of p53 protein, c-erbB-2 oncoprotein and estrogen receptor (ER) were immunohistochemically examined in order to discuss the relationship with histological subtype and histological grade. Histological grade correlated positively to the BrdU labeling index (LI) and overexpression of p53. High grade carcinoma demonstrated c-erbB-2 more frequently and exhibited a low incidence of ER. However, no significant relationship was found between BrdU LI, overexpression of p53 and c-erbB-2 and histological subtype. These results suggest that the histological grade does represent the proliferative activity of tumor cells and that adding the histological grade to the pathological diagnosis in invasive ductal breast carcinoma may be useful from the clinicopathological aspect concerning tumor behavior.     

Molecular mechanisms underlying IFN-{gamma}-mediated tumor growth inhibition induced during tumor growth inhibition induced during tumor immunotherapy with rIL-12

The present studnt Investigates the molecular by which IFN-produced as a result of in vitroIL-12 addministration exertsits anty-tumor,rIL-12 was administered three or five times intomice bearing CDA1M fibrosarcoma, OV-HM ovarian carcinoma orMCH-1-A1 fibosarcoma. This regimen induced complete regressionof CSA1M and OV-HM tumors but only transient growth inhibitionof MCH-1-A1 tumors. The anty-tumor effects of Il-12 were associatatedwith enhanced induction of IFN-becouse these effects were abrogatedby pretreatment of hosts with anti-IFN- antibody.Exposure inin vitro of the three types of tumor cells to rIFN- resultedin moderate to potent inhibition of tumor cell growth.IFNstimulatedthe expression of mRNAs for an inducible type of NO synthasa(INOS)in CSA1M cells and indoleamine 2,3-dioxygenasa (IDO),an enzyme capable of degrading tryptophan, in OV-HM cells ,but induced only marginal levels of these mRNAs in MCH-I-ALcells. In association withiNOS gene expression, INF--stimulatedCSA1M cells produced a large amount of NO which functioned toinhibit their own growth in vitro. Although OV-HM and MCH-1-A1cells did not produce NO, they also exhibited NO susceptibility.Whereasthe tumor masses from IL-12-treated CSA1M-bearing mice inducedhigher levels of INOS (for CSA1M) or IDO and iNOS (for OV-HM)mRNAs,the MCH-1-A1 tumor mass expressed lower levels of iNOS mRNAalone.Moreover, massive infiltration of CD4⁺and CD8⁺ T cellsand Mac-1⁺ cells was seen only in the CSA1M and OV-HM tumors.Thus, these results indicate that IFN- produced after IL-12treatment induces the expression of various genes with potentialto modulate tumor cells and growth by acting directly on tumorecells or stimulating tumor-infiltrating lymphold cells and thatthe effectiveness of IL12 therapy is assoiated with the operation if these mechanisms.     

Three-dimensional organization of the hepatic microvasculature in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant systemic fibrovascular dysplasia. Although hepatic vascular shunts are often observed in HHT, the responsible pathological mechanism is unknown. This issue was addressed by performing a 3-dimensional reconstruction study of the hepatic microvasculature of an HHT-involved liver in a 79-year-old woman. Clinical observation revealed high-output congestive heart failure and hepatic encephalopathy due to arteriovenous and portovenous shunts, respectively. Angiography revealed tortuous dilation of hepatic arterial branches and intrahepatic arteriovenous shunts. The 3-dimensional analysis of the autopsy liver revealed focal sinusoidal ectasia, arteriovenous shunts through abnormal direct communications between arterioles and ectatic sinusoids, and portovenous shunts due to frequent and large communications between portal veins and ectatic sinusoids. Type 1 HHT was suggested by the lack of endoglin immunoreactivity in the liver. The 3-dimensional reconstruction study of hepatic microvasculature was successful in identifying the pathological changes responsible for the intrahepatic shunts in HHT.     

Prevalence of chlamydia-pneumoniae-specific immunoglobulin M antibody and acute exacerbations of asthma in childhood]

BACKGROUND: Chlamydia pneumoniae is a frequent causative agent of acute respiratory disease and has been recently reported as a possible cause of asthma. We investigated the prevalence of C. pneumoniae infections in childhood patients with acute exacerbations of asthma. METHOD: One hundred twenty-six childhood patients with acute exacerbations of asthma, 77 with acute bronchitis and 22 Respiratory syncytial virus infections were studied. Serum samples were obtained and tested for C. pneumoniae-specific IgM antibody by Enzyme-Linked ImmunoSorbent Assay (ELISA). RESULTS: C. pneumoniae IgM-positive results were observed in 48.4% (Index value>or=1.60) and 23% (Index value>or=1.10) of patients with acute exacerbations of asthma. The prevalence of C. pneumoniae-specific IgM was significantly higher in asthma cases than in other subjects (p<0.05). CONCLUSION: Our data suggest that C. pneumoniae infection may trigger acute exacerbations of childhood asthma.     

Mutational analysis of the yeast multidrug resistance ABC transporter Pdr5p with altered drug specificity

Multidrug resistance ABC transporter Pdr5p of Saccharomyces cerevisiae is particularly important due to its ability to export a wide range of unrelated substrates. To clarify its function, we generated Pdr5p mutants by random mutagenesis and screened for mutants with altered drug specificity in vivo by using 5 drug compounds. Nine point mutations that caused significant changes in drug specificity distributed throughout the length of Pdr5p, namely, in the extracellular, transmembrane or cytoplasmic regions of the transporter. We then investigated their effects upon drug resistance, using 36 chemically related or distinct substrates. From this study, overall geometry of the Pdr5p was suggested to contribute in acquiring the enormous range of drug specificity. Based on their ability to inhibit the growth of the mutant strains, the 36 tested drugs were classified into: drugs to which the mutants responded differently (Group 1), drugs to which all the mutants showed sensitivity (Group 2), and drugs to which all the mutants exhibited resistance (Group 3). The ability of the compounds to be partitioned to the plasma membrane seemed an important factor for recognition by Pdr5p.     

Fate redirection of hippocampal astrocytes toward neuronal lineage by aggregate culture

Mammalian cells that have been committed to a certain cell lineage cannot be directed to other lineages. However, some astrocytes in the mammalian brains have been reported to represent plasticity to redirect to other cell lineages. We found that mouse hippocampal astrocytes cultured in aggregate forms of "astrosphere", redirected to MAP2-positive immature neurons. In astrospheres, basic HLH factors positively regulating neuronal differentiation were up-regulated and Id3 inhibiting basic HLH factors was down-regulated. Ectopic Id3 induction repressed redirection of astrocytes to a neuronal lineage, suggesting that astrosphere formation induced plasticity of astrocytes by changing the gene expression patterns.     

Genitourinary phenotype in XX patients with distal 9p monosomy

Although testicular development has been shown to be variably impaired in XY patients with distal 9p monosomy, ovarian and other genitourinary phenotype has poorly been studied in XX patients monosomic for the distal 9p region. Thus, we studied a 13-month-old infant with 46,XX,der(9)t(9;10)(p23;p13) (case 1) and an 11-year-old girl with 46,XX,der(9)t(9;16)(p23;q22) (case 2). Case 1 had primary hypogonadism (basal serum follicle stimulating hormone [FSH], 40.0 mIU/mL; leteinizing hormone [LH], 1.2 mIU/mL; estradiol [E2], <10 pg/mL), whereas case 2 had age-appropriate pubertal development (breast, Tanner stage 4; pubic hair, Tanner stage 3; menarche 11.7 years of age) and hormone values (FSH, 7.3 mIU/mL; LH, 6.7 mIU/mL; E2, 47 pg/mL). In addition, case 1 had hypoplastic labia majora, short distance between the vaginal orifice and the anus, and five renal cysts, and case 2 had anal atresia, short distance between the vaginal orifice and the anus, bilateral hydronephrosis of grade 3 with probable ureteropelvic junction stenosis, and renal dysfunction (serum creatinine, 1.52 mg/dL; urea nitrogen, 34.5mg/dL). Fluorescence in situ hybridization analysis for five regions and microsatellite analysis for 10 loci on 9p confirmed hemizygosity for the distal 9p region with the breakpoints between IFNA and D9S285 in case 1 and between D9S168 and D9S286 in case 2. The results, in conjunction with the previous data in XX patients with molecularly defined distal 9p monosomy, are consistent with the presence of a gene(s) involved in the development of indifferent gonad or subsequent ovarian differentiation in a approximately 11 Mb region distal to D9S168. In addition, it is possible that a gene(s) for anoperineal and renal development also maps distal to D9S168 and that for external genital development maps distal to D9S285 at the position approximately 16 Mb from the 9p telomere.