PMS2: a potential prognostic protein marker in oral squamous cell carcinoma.

BACKGROUND: An increase in oral squamous cell carcinoma (OSCC) cases was observed despite the reduction in exposure to classic risk factors. Although the exact cause of this trend remains unknown, epigenetic factors could be contributing to an increased occurrence of these tumors. This study aims to assess the influence of PMS2 protein immunoexpression on the prognosis of patients with OSCC. MATERIAL AND METHODS: This study comprised 76 cases of OSCC treated between 2011 and 2016. Immunohistochemical staining for PMS2 was performed. For evaluation, 10 fields per histological section were photographed at a 400x magnification and positively-stained cells were counted with Image J. Mann-Whitney and Kruskal-Wallis tests were used to compare the immunolabeling pattern with the clinical-pathological and prognostic characteristics. Survival analysis was performed with Chi-square, Long-Rank Mantel-Cox and Cox regression tests (p<0.05). RESULTS: An overexpression of PMS2 was observed in N0/1 tumors and in oral cancers found in unusual locations. In patients ≤60 years of age, high levels of PMS2 (>60%; p=0.041) were associated with low survival (p=0.029). In multivariate analysis, surgery combined with chemotherapy (p=0.030) and high PMS2 immunoexpression (p=0.042) significantly increased the risk of death for ≤60 years old patients. CONCLUSIONS: The findings of this study indicate that PMS2 can be a potential prognostic protein marker in OSCC patients 60 years of age and younger.

Purification and characterization of a mannose-containing disaccharide obtained from human pregnancy urine. A new immunoregulatory saccharide.

Endogenous mammalian lectin-like sugar-binding molecules have been previously described that have immunoregulatory properties. Further, the addition of defined simple saccharides to lymphocyte cultures has been shown to inhibit a variety of in vitro lymphocyte functions, presumably because these sugars are able to compete with the binding of endogenous lectins to critical membrane receptors. In this report, we describe the isolation and characterization of a D-mannose-containing disaccharide in human pregnancy urine that inhibits the proliferative response of human T lymphocytes. The inhibitory disaccharide was purified to homogeneity by sequential steps including affinity chromatography on immobilized concanavalin A and molecular sizing on Sephadex G-75 and then Fractogel 40S columns, with final purification on high-performance thin-layer chromatography. By mass spectrometry of the purified material as its permethylated derivative, the deduced structure of this compound was alpha-D-Manp 1-6-D-Man. To confirm that this disaccharide was in fact immunosuppressive, an identical disaccharide was prepared by sequential digestion of yeast cell wall polysaccharide. The urinary and yeast disaccharides had identical immunosuppressive properties. It has been previously reported that D-mannose is inhibitory for antigen-specific proliferative assays in the range of 10-50 mM. The purified alpha-D-Manp 1-6-D-Man disaccharide was inhibitory at 100-fold-lower concentrations. Further, while D-mannose inhibits T cell proliferation when added at anytime up to 24 h before harvest of a 6-d lymphocyte culture, alpha-D-Manp 1-6-D-Man disaccharide was inhibitory only if added at the initiation of culture and had no inhibitory effect if added just 24 h later. These data support the concept that simple sugar compounds can exhibit marked immunoregulatory activity in vitro. The impact of these molecules on the regulation of immune responses in vivo is unknown, as is their precise mechanism of action, but structural and chemical identification should now permit a detailed analysis of these issues.

Cooperative interaction of factor B and other complement components with mononuclear cells in the antibody-independent lysis of xenogeneic erythrocytes.

Synergistic cytotoxicity is a term used to describe a cytotoxic system in which xenogeneic erythrocyte target cells are lysed in the presence of nonimmune human mononuclear effector cells and antibody-depleted normal human serum. Neither the mononuclear cells nor the serum alone are cytolytic to the target erythrocytes. Previous studies have shown that the serum activity is not immunoglobulin and is heat-labile, suggesting a similarity to serum complement. In this report, sera deficient in various complement components as well as highly purified single complement components were tested with whole mononuclear cell populations and purified monocytes and lymphocytes to further characterize this cytotoxicity system. Whole mononuclear cell populations failed to mediate target cell lysis in sera deficient in C5 or factor B. However, C3-deficient serum, even in the presence of anti-C3 antibody, supported synergistic cytotoxicity normally. Purified lymphocytes were also normally cytotoxic in C3-deficient serum but failed to lyse targets in sera deficient in C5, C7, C8, or depleted of factor B. Purified monocytes failed to lyse the target cells only in factor B-depleted serum and could lyse the target cells in serum-free medium when purified factor B alone was added. Monocyte-mediated cytotoxicity induced by factor B was inhibited 73-100% by adding lymphocytes back to the purified monocytes. Thus, both lymphocytes and monocytes can serve as effector cells in this form of cytotoxicity but require cooperative interaction with different sets of complement components. In addition, lymphocytes can modulate the monocyte-mediated form of target cell lysis associated with factor B.

Uromodulin: a unique 85-kilodalton immunosuppressive glycoprotein isolated from urine of pregnant women.

Crude fractions of urine from pregnant women are immunosuppressive in vitro. An 85-kilodalton immunosuppressive glycoprotein purified to homogeneity from such urine inhibited in vitro assays of human T-cell and monocyte activity at concentrations of 10(-9) to 10(-11) molar. This material was nontoxic and blocked early events required for normal T-cell proliferation in vitro. On the basis of its tissue source and its in vitro activity, the name "uromodulin" is proposed for this glycoprotein.

Uromodulin (Tamm-Horsfall glycoprotein): a renal ligand for lymphokines.

The protein portion of the immunosuppressive glycoprotein uromodulin is identical to the Tamm-Horsfall urinary glycoprotein and is synthesized in the kidney. Evidence that the glycoproteins are the same is based on amino acid sequence identity, immunologic cross-reactivity, and tissue localization to the thick ascending limb of Henle's loop. Nucleic acid sequencing of clones for uromodulin isolated from a complementary DNA bank from human kidney predicts a protein 639 amino acids in length, including a 24--amino acid leader sequence and a cysteine-rich mature protein with eight potential glycosylation sites. Uromodulin and preparations of Tamm-Horsfall glycoprotein bind to recombinant murine interleukin-1 (rIL-1) and human rIL-1 alpha, rIL-1 beta, and recombinant tumor necrosis factor (rTNF). Uromodulin isolated from urine of pregnant women by lectin adherence is more immunosuppressive than material isolated by the original salt-precipitation protocol of Tamm and Horsfall. Immunohistologic studies demonstrate that rIL-1 and rTNF bind to the same area of the human kidney that binds to antiserum specific for uromodulin. Thus, uromodulin (Tamm-Horsfall glycoprotein) may function as a unique renal regulatory glycoprotein that specifically binds to and regulates the circulating activity of a number of potent cytokines, including IL-1 and TNF.

Activity of triciribine and triciribine-5'-monophosphate against human immunodeficiency virus types 1 and 2.

Triciribine (TCN) and its 5'-monophosphate (TCN-P) are novel tricyclic compounds with known antitumor activity; TCN-P is currently in phase II human clinical trials. We now report that these compounds have potent and selective activity against HIV-1 and HIV-2. Using a syncytial plaque assay, TCN and TCN-P were active against HIV-1 at 0.01-0.02 microM and had differential selectivities of 2250 and 1900, respectively, compared to 1850 for AZT. In contrast, TCN and TCN-P had minimal selectivity against human cytomegalovirus (50 and 27, respectively). TCN and TCN-P markedly inhibited HIV-1-induced p24 core antigen production, reverse transcriptase, and infectious virus production in a dose-dependent manner using HIV-1 acutely infected CEM-SS, H9, and persistently infected H9IIIB and U1 cells. In acutely infected PBL cells, TCN and TCN-P inhibited reverse transcriptase and infectious virus production but not p24 core antigen production. Using a microtiter XTT assay, TCN and TCN-P were active against a panel of HIV-1 and HIV-2 strains at IC50 values ranging from 0.02 to 0.46 microM. Evaluation of matched pairs of predrug and postdrug therapy HIV-1 isolates established that AZT-resistant and TIBO-resistant variants of HIV-1 were sensitive to TCN or TCN-P. Furthermore, unlike AZT and other fraudulent nucleosides, neither TCN, TCN-P, nor TCN-TP inhibited the viral reverse transcriptase. Thus, even though triciribine is a nucleoside chemically, it does not act biologically by classic nucleoside modalities but rather by a unique mechanism yet to be elucidated.

Effector cell sensitivity to sugar moieties. I. Inhibition of human natural killer cell activity by monosaccharides.

Human natural killer (NK) cells recognize multiple target antigens. The ligands (antigens) involved in the effector-target cell interaction have not been extensively identified. In the present study, assays of NK activity in the presence of a panel of monosaccharides demonstrated inhibition of cytolysis in a dose-response fashion. We propose that NK cell activity involves the recognition of carbohydrate structures on target cells via receptors on the effector cell surface.

Spontaneous cytotoxicity by human peripheral blood monocytes: inhibition by monosaccharides and oligosaccharides.

The mechanism by which nonimmune cytotoxic effector cells recognize "foreign" targets for cytotoxic attack was investigated utilizing a model system in which cultured human monocytes become cytotoxic to a broad variety of xenogeneic erythrocyte target cells. Such spontaneously cytotoxic human monocytes lyse targets such as chicken (CRBC), horse (HRBC), and rat (RRBC) erythrocytes rapidly and without the addition of exogeneous lectin or antibody. It was found that a variety of simple sugars were capable of blocking the expression of cytotoxicity by precultured human monocytes, and that different oligosaccharides blocked the killing of different targets. For example, cellobiose, a beta 1-4 dimer of D (+) glucose, blocked, CRBC and HRBC lysis in vitro, but had no effect on RRBC lysis. Arabinogalactan (a complex polysaccharide with a galactose beta 1-3 galactose backbone and galactose beta 1-6 galactose side chains with terminal arabinoses), however, blocked HRBC killing, but exhibited only minor inhibition of CRBC killing. Other aspects of cell-mediated function, including lymphocyte transformation to PHA, cell viability as assessed by trypan blue exclusion, monocyte phagocytosis of opsonized CRBC's, and PHA-induced cellular cytotoxicity of CRBC targets, were essentially intact in the presence of identical concentrations of oligosaccharides. Such target-specific inhibition is consistent with the hypothesis that cytotoxic human monocytes recognize various targets through surface receptors which interact with specific monosacchardies, disaccharide, and oligosaccharide sequences present on the target surface.

Teaching resuscitation to pediatric residents: the effects of an intervention.

OBJECTIVE: To evaluate the effectiveness of an educational intervention on pediatric residents' resuscitation fund of knowledge, technical skills, confidence, and overall performance. DESIGN: Prospective, nonconcurrent, controlled interventional trial. SETTING: Urban pediatric tertiary care hospital. PARTICIPANTS: An intervention group (IG) of 28 pediatric residents graduating in 1997, and a control group (CG) of 30 pediatric residents graduating in 1996. INTERVENTIONS: Resuscitation course with didactic lectures and skills practice stations, as well as a minimum of 3 practice mock resuscitations with immediate feedback throughout postgraduate year 3. MAIN OUTCOME MEASURES: Fund of knowledge, using the Pediatric Advanced Life Support test and short answer test; technical skills, using the Airway and Vascular Access Skills Assessment; experience and confidence, using an anonymous survey; and overall performance, evaluated using a videotaped mock resuscitation test. RESULTS: The IG scored better on the short answer test (P<.001). A larger number of IG residents were successful in the completion of ancillary airway maneuvers and femoral vascular access (P =.02), as well as endotracheal intubation (P =.004) and intraosseous access (P =.002). The IG was more confident in their leadership role (P =.0001) and technical skills (P =.05). Trends toward improved overall performance were noted for the IG mock resuscitations. Residents in the IG were more likely to assess the airway in fewer than 2 minutes (P =.02), recognize the threat to life in fewer than 5 minutes (P =.02), and complete the primary survey in a timely fashion (P =.05). They required fewer prompts (P =.04) and made fewer mistakes (P =.07). CONCLUSIONS: A structured, formal curriculum can improve the necessary fund of knowledge, skills, confidence, and leadership required for resuscitation.

C-type natriuretic peptide modulates bidirectional plasticity in hippocampal area CA1 in vitro.

C-type natriuretic peptide (CNP) and the natriuretic peptide receptor B (NPR-B) are expressed throughout the hippocampus. We tested whether CNP affected long-term potentiation (LTP) or long-term depression (LTD) in area CA1. Field potentials (FP) were simultaneously recorded in stratum pyramidale (SP) and stratum radiatum (SR) of area CA1 in rat hippocampal slices. To induce LTD and LTP stimulation was applied to SR in area CA1 at 1 and 5 Hz and 30-100 Hz, respectively. CNP (100 nM) increased LTD magnitude while LTP induction was impeded. Thus, in the presence of CNP the threshold for LTP induction was shifted to higher stimulus frequencies, a modulation that showed layer-specific differences in area CA1. Effects of CNP were prevented by the NPR-B antagonist HS-142-1. In the presence of the GABA(A) receptor blocker bicuculline (BMI, 5 microM), CNP-mediated effects were attenuated in SP and SR. Intracellular recordings under this condition revealed that CNP significantly reduced number of action potentials generated during depolarizing current steps. The input resistance of CA1 cells and amplitude of isolated excitatory postsynaptic potential (EPSPs) were significantly increased by CNP whereas these changes were not observed in the absence of BMI. 100 Hz stimulation induced stable potentiation of the EPSP amplitude in CA1 pyramidal cells while this effect was strongly attenuated by CNP. This effect was prevented by BMI. Immunohistochemistry indicated that the peptide binds to receptors expressed on pyramidal cells and GAD(65/67)-immunopositive interneurons. 20 Hz stimulation, applied for 30 s, induced LTP in SR and SP. CNP attenuated LTP in SP and reversed LTP into LTD in SR. These effects were mimicked by low-dose dl-2-amino-5-phosphonopentanoic acid (dl-APV) (10 microM) suggesting partial N-methyl d-aspartate (NMDA) receptor dependency of CNP-mediated effects. Together, our data suggest that CNP is involved in the regulation of bidirectional plasticity in area CA1 potentially by modulating GABA(A)-mediated inhibition and NMDA receptors.

C-type natriuretic peptide decreases hippocampal network oscillations in adult rats in vitro.

C-type natriuretic peptide (CNP) is an abundant neuropeptide in the human brain and the cerebrospinal fluid. CNP is involved in anxiogenesis and exerts its effects through the natriuretic peptide receptor B (NPR-B), which is expressed in the hippocampus. Hippocampal network oscillations of distinct frequency bands like gamma (gamma)-oscillations and sharp wave-ripple complexes (SPW-Rs) are likely involved in various cognitive functions such as the storage of information and memory consolidation in vivo. Here, we tested the effects of CNP on distinct network oscillations in horizontal slices of rat hippocampus. We found that CNP decreased the power of stimulus- and ACh/physostigmine-induced gamma-oscillations. In contrast to stimulus-induced gamma-oscillations, CNP increased the frequency of ACh-induced, persistent network oscillations. Moreover, the peptide hormone reduced the incidence of LTP-associated SPW-Rs in area CA3 and CA1. Immunohistochemistry indicates that the peptide binds to receptors expressed on a subset of GAD 65-67-immunopositive cells in addition to binding to principal and other presumably non-neuronal cells. CNP caused a hyperpolarization of CA3 neurons increased their input resistance and decreased inhibitory conductance. Together, our data suggest that the effects of CNP on synchronized hippocampal network oscillations might involve effects on hippocampal interneurons.

Severe gastrointestinal disease due to HIV-1-seronegative AIDS.

An HIV-1 seronegative man presented with odynophagia, dysphagia, diarrhea, tenesmus and a 50-lb weight loss. A large esophageal ulcer and a rectal fissure were identified endoscopically. Stool samples and biopsy specimens from the esophageal ulcer, duodenum, colon and rectum were negative for pathogens. Seronegative AIDS was suspected, and high levels of HIV-1 mRNA (> 242,000 copies/mL) were detected. The esophageal ulcer responded to oral steroids and the HIV-1 infection to highly active anti-retroviral therapy (HAART). The virus isolated from the patient and an HIV-1 seropositive, asymptomatic, female sex worker with whom he had recently terminated a one-year heterosexual relationship showed sequence homology, indicating her as the source of his virus. The unusual presentation of severe gastrointestinal disease in an HIV-1 seronegative man with HIV-1 viremia underscores the importance of including AIDS in the differential diagnosis of wasting syndrome (i. e., B-type symptoms such as fever, night sweats, weight loss) in patients who are HIV-1 seronegative but at risk for AIDS.

Neutralizing antibody responses in acute human immunodeficiency virus type 1 subtype C infection.

The study of the evolution and specificities of neutralizing antibodies during the course of human immunodeficiency virus type 1 (HIV-1) infection may be important in the discovery of possible targets for vaccine design. In this study, we assessed the autologous and heterologous neutralization responses of 14 HIV-1 subtype C-infected individuals, using envelope clones obtained within the first 2 months postinfection. Our data show that potent but relatively strain-specific neutralizing antibodies develop within 3 to 12 months of HIV-1 infection. The magnitude of this response was associated with shorter V1-to-V5 envelope lengths and fewer glycosylation sites, particularly in the V1-V2 region. Anti-MPER antibodies were detected in 4 of 14 individuals within a year of infection, while antibodies to CD4-induced (CD4i) epitopes developed to high titers in 12 participants, in most cases before the development of autologous neutralizing antibodies. However, neither anti-MPER nor anti-CD4i antibody specificity conferred neutralization breadth. These data provide insights into the kinetics, potency, breadth, and epitope specificity of neutralizing antibody responses in acute HIV-1 subtype C infection.

Uromodulin. An immunosuppressive 85-kilodalton glycoprotein isolated from human pregnancy urine is a high affinity ligand for recombinant interleukin 1 alpha.

Uromodulin is an 85-kDa immunosuppressive glycoprotein originally isolated from human pregnancy urine. It exhibits immunosuppressive activity in vitro at concentrations between 10(-9) and 10(-11) M. Recent data demonstrate that uromodulin is able to specifically inhibit in vitro assays dependent upon interleukin 1 (IL-1). We now present evidence that uromodulin is a high affinity ligand for recombinant murine IL-1 alpha. Since uromodulin has been purified to homogeneity, this should allow extensive further characterization of the mechanism of action of both uromodulin and IL-1.

Evidence that recombinant IL 1 alpha exhibits lectin-like specificity and binds to homogeneous uromodulin via N-linked oligosaccharides.

Uromodulin, a recently described immunosuppressive glycoprotein isolated from human pregnancy urine, has been shown to inhibit T cell proliferative assays dependent upon interleukin 1 (IL 1). We have also recently demonstrated that uromodulin binds specifically to IL 1. We now show that not only the biologic activity but also the binding affinity of uromodulin for recombinant IL 1 is dependent upon intact glycosylation. Furthermore, oligosaccharides isolated from pronase-digested uromodulin are immunosuppressive by themselves and are able to compete with native uromodulin for binding to IL 1. We conclude that recombinant IL 1 exhibits lectin-like specificity, and uromodulin is a biologically functional glycoprotein target of the lectin-like specificity of IL 1.

The immune system: relation to sepsis and multiple organ failure.

The immune system plays a dual role in the pathogenesis of sepsis and organ failure, intended for host defense but also possessing significant cytodestructive capacity. As the understanding of the epidemiology and pathophysiology of these disorders improves, so too does the appreciation for the complexity of this system. No longer is the immune response viewed as simply cellular or humoral but rather as a network of cells, chemical mediators, and molecular elements. The interactions between these various components serve to regulate and coordinate the inflammatory response. When this fine balance is lost, the inflammatory response becomes pathologic and self-destructive. Organ injury ensues, and with this injury, further escalation of the inflammatory response occurs; becoming a self-perpetuating process. Conventional therapy is limited to supportive care and has been ineffective in improving mortality. To date, efforts to modulate the inflammatory response by inhibition of specific components have been unsuccessful. In the future, better patient selection, combination therapy (perhaps using strategies of early augmentation followed by inhibition), and alternative techniques such as blood purification may prove to be more effective.

The lectin-like interaction between recombinant tumor necrosis factor and uromodulin.

The polypeptide of uromodulin, an immunosuppressive glycoprotein isolated from human urine, has been shown to be identical to that of Tamm-Horsfall glycoprotein and is synthesized exclusively in the kidney (Hession, C., Decker, J. M., Sherblom, A. P., Kumar, S. (1987) Science 237, 1479-1484). Uromodulin binds recombinant murine interleukin 1 alpha with high affinity, and this binding can be inhibited by addition of specific saccharides (Muchmore, A. V., and Decker, J. M. (1987) J. Immunol. 138, 2541-2546). We now report that uromodulin binds recombinant human tumor necrosis factor (rTNF) with high affinity. Both diacetylchitobiose and Man(alpha 1-6)(Man(alpha 1-3]-Man-O-ethyl are effective inhibitors of the binding, whereas a wide variety of other saccharides are not inhibitory. Although Tamm-Horsfall glycoprotein contains predominantly tetraantennary N-linked chains, the binding to rTNF is unaffected by removal of terminal sialic acid, galactose, and N-acetylhexosamine residues. Fractionation of a Pronase digest of uromodulin by gel filtration yields material that inhibits the binding of uromodulin to rTNF but is of lower molecular weight than the major oligosaccharide. Uromodulin does not inhibit the cytotoxic activity of rTNF as monitored by lysis of tumor cell targets but effectively protects mice from lethal challenge with lipopolysaccharide, an event that may involve lymphokine toxicity. We have previously shown that rTNF binds to sections of human kidney and is localized in the same region as uromodulin. Thus, rTNF interacts with uromodulin via carbohydrate chains that are less processed than the major tetraantennary chain, and this interaction may be critical in promoting clearance and/or reducing toxicity of TNF and other lymphokines.

Evolutionary and developmental aspects of T-cell recognition.

Studies relating to the nature of the antigen-specific T-cell receptor are reviewed in the light of present knowledge of phylogenetic and ontogenetic development. It is suggested that this evidence supports the concept that immunoglobulin (Ig) is the T-cell receptor, and that the following conclusions may be tentatively drawn.