Oral hairy leukoplakia. Histopathologic and cytopathologic features of a subclinical phase

Accurate diagnosis of oral hairy leukoplakia (OHL) is important because it may be an early indicator of undiagnosed HIV infection; moreover, it may be a prognostic indicator. Our purpose was to investigate the histopathologic features of subclinical OHL and to evaluate and support the rationale of detecting subclinical OHL with cytopathology. The Epstein-Barr virus (EBV) was detected by immunohistochemistry and in situ hybridization in 4 cases of macroscopically normal lateral borders of tongue mucosa from 8 AIDS necropsies and in none of 8 controls. The histopathologic features were specific when based on nuclear changes: Cowdry type A inclusion, ground glass, and nuclear beading. Smears were obtained from 50 patients with AIDS, without OHL, from the scraping of lateral borders of the tongue. Numerous clusters of the cells were associated with Candida organisms (30% of cases). Nuclear changes were observed in 12 patients (24%) on both sides of the tongue. We describe the histopathologic features of subclinical OHL, and our observations suggest that cytopathology can detect OHL in the subclinical phase.     

The haemotoxicity of mitomycin in a repeat dose study in the female CD-1 mouse

Mitomycin (MMC), like many antineoplastic drugs, induces a predictable, dose-related, bone marrow depression in man and laboratory animals; this change is generally reversible. However, there is evidence that MMC may also cause a late-stage or residual bone marrow injury. The present study in female CD-1 mice investigated the haematological and bone marrow changes induced by MMC in a repeat dose study lasting 50 days. Control and MMC-treated mice were dosed intraperitoneally on eight occasions over 18 days with vehicle, or MMC at 2.5 mg/kg, autopsied (n = 6-12) at 1, 7, 14, 28, 42 and 50 days after the final dose and haematological changes investigated. Femoral nucleated bone marrow cell counts and levels of apoptosis were also evaluated and clonogenic assays carried out; serum levels of FLT3 ligand (FL) were assessed. At day 1 post-dosing, MMC induced significant reductions in RBC, Hb and haematocrit (HCT) values, and there were decreases in reticulocyte, platelet, and femoral nucleated cell counts (FNCC); neutrophil, lymphocyte and monocyte values were also significantly reduced. On days 7 and 14 post-dosing, all haematological parameters showed evidence of a return towards normal values, but at these times, and at day 28, values for RBC and FNCC remained significantly reduced in comparison with controls. At days 42 and 50 post-dosing, many haematological parameters in MMC-treated mice had returned to control levels; however, there remained evidence of late-stage effects on RBC, Hb and HCT values, and FNCC also continued to be significantly decreased. Results for granulocyte-macrophage colony-forming units and erythroid colonies showed a profound decrease immediately post-dosing, but a return to normal values was evident at day 50. Serum FL concentrations demonstrated very significant increases in the immediate post-dosing period, but a return to normal was seen at day 50 post-dosing; a relatively similar pattern was seen in the number of apoptotic femoral marrow nucleated cells. The histopathological examination of kidney tissues from MMC animals at day 42 and 50 post-dosing showed evidence of hydronephrosis with cortical glomerular/tubular atrophy and degeneration. It is therefore concluded that MMC administered on eight occasions over 18 days to female CD-1 mice at 2.5 mg/kg induced profound changes in haematological and bone marrow parameters in the immediate post-dosing period with a return to normal levels at day 50 post-dosing; however, there was evidence of mild but significant late-stage/residual effects on RBC and FNCC, and on cells of the erythroid lineage in the bone marrow.     

Clostridium difficile vaccine and serum immunoglobulin G antibody response to toxin A

There is a strong association between serum antibody responses to toxin A and protection against Clostridium difficile diarrhea. A parenteral C. difficile toxoid vaccine induced very-high-level responses to anti-toxin A immunoglobulin G (IgG) in the sera of healthy volunteers. After vaccination, the concentrations of anti-toxin A IgG in the sera of all 30 recipients exceeded the concentrations that were associated with protection in previous clinical studies. Furthermore, the median concentration of serum anti-toxin A IgG in the test group was 50-fold higher than the previous threshold. These findings support the feasibility of using a vaccine to protect high-risk individuals against C. difficile-associated diarrhea and colitis.     

Proteomic and postproteomic characterization of keratan sulfate-glycanated isoforms of thyroglobulin and transferrin uniquely elaborated by papillary thyroid carcinomas

Previous studies have suggested that surface components of papillary thyroid carcinoma (PTC) cells may be aberrantly glycanated, but the precise nature of these molecules has not been unveiled nor documented to be of clinical relevance. A monoclonal antibody was raised against a unique keratan sulfate (KS) determinant and used to differentially screen benign and malignant thyroid tissue for the expression of components carrying these moieties. In a total of 349 cases of benign and malignant thyroid lesions, 100% of the 115 PTC cases examined (including various histological subtypes) were found to contain KS-bearing molecules, whereas these were virtually absent from benign tissues and other thyroid tumors, with the exception of 21% of the follicular carcinoma cases analyzed. A composite immunoaffinity chromatography, immunochemistry, and mass spectrometric approach revealed that the PTC-specific KS-bearing macromolecules were unique glycoforms of thyroglobulin and transferrin. Combined, reciprocal immunoprecipitation and Western blotting further indicated that the former glycoform predominated and that most of the transferrin produced by PTC was glycanated with KS moieties. Fluorescent keratanase II-based fingerprinting of the KS moieties bound to these isoforms further demonstrated several PTC-specific peculiarities: 1) that a considerable portion of the moieties was covalently attached via a novel core protein linkage structure; 2) they had an unusual extended average length; 3) an unusual relative ratio of highly sulfated disaccharides terminating with alpha (2-3)-linked N-acetylneuraminic acid capping residues; and 4) a novel unidentified oligosaccharide moiety at the nonreducing terminus. Comparative analysis of the relative distribution of transferrin in benign versus PTC tissues highlighted a marked malignancy-associated abundance of the molecule, with a >75% frequency in expression in PTC. These findings demonstrate that PTC cells synthesize unique post-translationally modified thyroglobulin and transferrin variants in situ that may be directly exploitable for diagnosis, through histological and noninvasive cytological procedures; for devising novel strategies for antibody-guided imaging of this tumor in vivo; and for postsurgery follow-up of PTC patients.     

Astrocytes give rise to oligodendrogliomas and astrocytomas after gene transfer of polyoma virus middle T antigen in vivo

The cells of origin for oligodendrogliomas and astrocytomas are not known but are presumed to be oligodendrocyte and astrocyte precursors, respectively. In this paper we report the generation of mixed gliomas from in vivo transformation of glial fibrillary acidic protein (GFAP)-positive cells (differentiated astrocytes) with polyoma virus middle T antigen (MTA). MTA is a powerful oncogene that activates a number of signal transduction pathways, including those proposed to be involved in gliomagenesis, and has been shown to induce tumors in many cell types. We have achieved transfer of MTA expression specifically to GFAP(+) cells in vivo using somatic cell gene transfer, and find resultant formation of anaplastic gliomas with mixed astrocytoma and oligodendroglioma morphological features. We conclude that GFAP- expressing astrocytes, with appropriate signaling abnormalities, can serve as the cell of origin for oligodendrogliomas, astrocytomas, or mixed gliomas.     

Severe maternal psychopathology and infant-mother attachment

Eighty-two mother-infant dyads, comprising women with psychiatric disorder and individually matched controls, were followed up over the children's 1st year of life. The mothers with mental illness consisted of two subgroups: first, 25 severely mentally ill mothers who had been admitted to a psychiatric unit with their infants; and second, 16 mothers from a community sample meeting research diagnostic criteria for unipolar, nonpsychotic depression. With the exception of six dyads in the in-patient group, observations were made of the mother-infant interaction and the quality of the infant-mother attachment relationship at 12 months. The nature and course of the mothers' illness was also documented. Although few residual symptoms of maternal mental illness were detected at 1 year postpartum, interactional disturbances were evident among the case group dyads. A strong association was revealed between infant-mother attachment quality and maternal diagnosis; a manic episode of illness in the postpartum period was related to security in the attachment relationship, and psychotic or nonpsychotic depression was related to insecurity. Concurrent patterns of mother-infant interaction provided support for this finding.     

Proximal tubular epithelial cell integrins respond to high glucose by altered cell-matrix interactions and differentially regulate matrixin expression

Thickening of the tubular basement membrane (TBM) occurs in diabetic nephropathy, but the effects of high glucose on the functional aspects of proximal tubular epithelial cells are not clearly understood. In the present study, we examined the effects of elevated glucose concentrations on (a) integrin expression by human proximal tubular epithelial cells (HK-2) and integrin-mediated interactions with type IV collagen (colIV) and laminin, major components of TBM; (b) the expression of matrixins/matrix metalloproteinases (MMPs), which is regulated by integrins; and (c) the expression of tissue inhibitors of metalloproteinases (TIMPs). HK-2 cells cultured in 25 mM glucose underwent a reduction of the expression of alpha3, beta1, alpha(v)beta3, and alpha5 integrin subunits, with a concomitant increase of the alpha2 subunit, compared with cells grown in 5 mM glucose. Adhesion experiments demonstrated that high glucose led to increased cell adhesion on either colIV or laminin. Experiments of competition of adhesion using anti-integrin antibodies indicated that HK-2 cells in 5 mM glucose used mainly alpha(v)beta3 and alpha5beta1 integrins to adhere to colIV, whereas in 25 mM glucose they additionally used alpha2beta1. In the case of laminin, a beta1-mediated adhesion was observed when HK-2 cells were in 5 mM glucose, whereas in 25 mM glucose, alpha2beta1 and alpha(v)beta3 were also involved. Elevated glucose concentrations resulted in decreased expression of MMP-9 and MMP-2, whereas an increase in TIMP-1 and a decrease in TIMP-2 expression were observed. We also examined which integrins mediated the expression and secretion of matrixins MMP-2 and MMP-9. Ligation of alpha3beta1 with mAbs resulted in induction of MMP-2 expression and secretion, whereas antibody ligation of alpha(v)beta3 led to down-regulation of MMP-9. The above data implicate integrins of proximal tubular epithelial cells in the regulation of MMPs and in the development of TBM thickening in diabetic nephropathy.