Regulation of intracellular calcium in dispersed fat body trophocytes of the cockroach, Periplaneta americana, by hypertrehalosemic hormone

Incubation of trophocytes from dissaggregated fat body of Periplaneta americana with either of the hypertrehalosemic hormones, HTH-I or HTH-II, leads to an increase in the cytosolic concentration of Ca(2+) from approximately 80 to approximately 310nM with a rise time of approximately 110s. The Ca(2+) concentration then declines to the resting level during the ensuing 5min. In the absence of extracellular Ca(2+) the increase in [Ca(2+)](i) due to HTH is limited to approximately 100nM. The calmodulin inhibitors calmidazolium and W-7 also limit to a similar degree the ability of HTH to increase [Ca(2+)](i). Phorbol 12-myristate 13-acetate, an activator of protein kinase C, was shown to block Ca(2+) entry through the plasma membrane. Additional evidence to support the view that HTH enhances Ca(2+) influx has been obtained by measuring the quenching of fura-2 fluorescence when Ca(2+) is replaced with Mn(2+).

The proteinase-activated receptor 2 is involved in nociception

The proteinase-activated receptor 2 is expressed on a subset of primary afferent neurons and may participate in the neurogenic component of inflammation. We hypothesized that this receptor may also play a role in neuronal sensitization and contribute to the pathogenesis of pain in inflammatory conditions such as pancreatitis. Using a specific proteinase-activated receptor 2 activating peptide, we found evidence of such sensitization in vitro in the form of enhanced capsaicin- and KCl-evoked release of calcitonin gene-related peptide, a marker for nociceptive signaling. We then demonstrated that injection of the proteinase-activated receptor 2 activating peptide into the pancreatic duct can activate and sensitize pancreas-specific afferent neurons in vivo, as measured by Fos expression in the dorsal horn of the spinal cord. These observations suggest that proteinase-activated receptor 2 contributes to nociceptive signaling and may provide a novel link between inflammation and pain.

Low viscosity Ektacytometry and its validation tested by flow chamber

The flow chamber was used to observe the orientation and small deformation of red blood cells (RBCs) in a shear flow of low viscosity. With the aid of computer software, the percentage of RBCs oriented to the C=0 orbit (OI)(F) and the degree of deformation (DI)(F) of such RBCs were calculated by processing the photographs. It was found that these parameters were highly correlated, respectively, to the orientation index (OI)(E) and the small deformation index (DI)(E) obtained by our low viscosity Ektacytometry (LVE). Thus, our flow chamber research has provided direct evidence to validate the use of this low viscosity Ektacytometry. Although there are relative merits for the flow chamber method using low viscosity medium, the LVE is more likely to be applied in clinic for its simplicity and convenience.

A streamlined process to phenotypically profile heterologous cDNAs in parallel using yeast cell-based assays

To meet the demands of developing lead drugs for the profusion of human genes being sequenced as part of the human genome project, we developed a high-throughput assay construction method in yeast. A set of optimized techniques allows us to rapidly transfer large numbers of heterologous cDNAs from nonyeast plasmids into yeast expression vectors. These high- or low-copy yeast expression plasmids are then converted quickly into integration-competent vectors for phenotypic profiling of the heterologous gene products. The process was validated first by testing proteins of diverse function, such as p38, poly(ADP-ribose) polymerase-1, and PI 3-kinase, by making active-site mutations and using existing small molecule inhibitors of these proteins. For less well-characterized genes, a novel random mutagenesis scheme was developed that allows a combination selection/screen for mutations that retain full-length expression and yet reverse a growth phenotype in yeast. A broad range of proteins in different functional classes has been profiled, with an average yield for growth interference phenotypes of approximately 30%. The ease of manipulation of the yeast genome affords us the opportunity to approach drug discovery and exploratory biology on a genomic scale and shortens assay development time significantly.

Mutant p53 cooperates with ETS and selectively up-regulates human MDR1 not MRP1

The most frequently expressed drug resistance genes, MDR1 and MRP1, occur in human tumors with mutant p53. However, it was unknown if mutant p53 transcriptionally regulated both MDR1 and MRP1. We demonstrated that mutant p53 did not activate either the MRP1 promoter or the endogenous gene. In contrast, mutant p53 strongly up-regulated the MDR1 promoter and expression of the endogenous MDR1 gene. Notably, cells that expressed either a transcriptionally inactive mutant p53 or the empty vector showed no endogenous MDR1 up-regulation. Transcriptional activation of the MDR1 promoter by mutant p53 required an Ets binding site, and mutant p53 and Ets-1 synergistically activated MDR1 transcription. Biochemical analysis revealed that Ets-1 interacted exclusively with mutant p53s in vivo but not with wild-type p53. These findings are the first to demonstrate the induction of endogenous MDR1 by mutant p53 and provide insight into the mechanism.

Re-engineering monovalent cation binding sites of methylamine dehydrogenase: effects on spectral properties and gated electron transfer

Methylamine dehydrogenase (MADH) is a tryptophan tryptophylquinone (TTQ)-dependent enzyme that catalyzes the oxidative deamination of primary amines. Monovalent cations are known to affect the spectral properties of MADH and to influence the rate of the gated electron transfer (ET) reaction from substrate-reduced MADH to amicyanin. Two putative monovalent cation binding sites in MADH have been identified by X-ray crystallography [Labesse, G., Ferrari, D., Chen, Z.-W., Rossi, G.-L., Kuusk, V., McIntire, W. S., and Mathews, F. S. (1998) J. Biol. Chem. 273, 25703-25712]. One requires cation-pi interactions involving residue alpha Phe55. An alpha F55A mutation differentially affects these two monovalent cation-dependent phenomena. The apparent K(d) associated with spectral perturbations increases 10-fold. The apparent K(d) associated with enhancement of the gated ET reaction becomes too small to measure, indicating that either it has decreased more than 1000-fold or the mutation has caused a conformational change that eliminates the requirement for the cation for the gated ET. These results show that of the two binding sites revealed in the structure, cation binding to the distal site, which is stabilized by the cation-pi interactions, is responsible for the spectral perturbations. Cation binding to the proximal site, which is stabilized by several oxygen ligands, is responsible for the enhancement of the rate of gated ET. Another site-directed mutant, alpha F55E MADH, exhibited cation binding properties that were the same as those of the native enzyme, indicating that interactions with the carboxylate of Glu can effectively replace the cation-pi interactions with Phe in stabilizing monovalent cation binding to the distal site.

Extracellular calmodulin stimulates light-independent RbcS-GUS expression in suspension-cultured cells of transgenic tobacco

The RbcS genes encode the small subunits of rubisco; the expression of these genes is controlled in a light-dependent and independent manner. It has been reported that intracellular calmodulin (CaM) is involved in light-dependent RbcS expression. In this report, the role of extracellular CaM in regulating expression of RbcS in darkness was examined. The time course of expression of RbcS-GUS and that of the secretion of CaM in the suspended transgenic tobacco cells in darkness were very similar. Both showed initial increase followed by decline with maximum CaM secretion preceding maximum GUS expression by 24 h. The concentration of CaM in the culture medium is regulated light independently. Purified CaM alone added to the media enhanced RbcS-GUS expression in darkness. The addition of membrane-impermeable CaM inhibitors, such as anti-CaM antiserum or W7-agarose, repressed the expression of RbcS-GUS in darkness, but this inhibitory effect was completely reversed by adding exogenous purified CaM. These results provide the first evidence that extracellular CaM is involved in the regulation of light-independent RbcS gene expression.

Epileptogenesis induces long-term alterations in intracellular calcium release and sequestration mechanisms in the hippocampal neuronal culture model of epilepsy

Calcium and calcium-dependent processes have been hypothesized to be involved in the induction of epilepsy. It has been shown that epileptic neurons have altered calcium homeostatic mechanisms following epileptogenesis in the hippocampal neuronal culture (HNC) and pilocarpine models of epilepsy. To investigate the mechanisms causing these alterations in [Ca2+]i homeostatic processes following epileptogenesis, we utilized the HNC model of in vitro 'epilepsy' which produces spontaneous recurrent epileptiform discharges (SREDs). Using [Ca2+]i imaging, studies were initiated to evaluate the mechanisms mediating these changes in [Ca2+]i homeostasis. 'Epileptic' neurons required much longer to restore a glutamate induced [Ca2+]i load to baseline levels than control neurons. Inhibition of Ca2+ entry through voltage and receptor gated Ca2+ channels and stretch activated Ca2+ channels had no effect on the prolonged glutamate induced increase in [Ca2+]i in epileptic neurons. Employing thapsigargin, an inhibitor of the sarco/endoplasmic reticulum calcium ATPase (SERCA), it was shown that thapsigargin inhibited sequestration of [Ca2+]i by SERCA was significantly decreased in 'epileptic' neurons. Using Ca2+ induced Ca2+ release (CICR) cell permeable inhibitors for the ryanodine receptor (dantrolene) and the IP3 receptor (2-amino-ethoxydiphenylborate, 2APB) mediated CICR, we demonstrated that CICR was significantly augmented in the 'epileptic' neurons, and determined that the IP3 receptor mediated CICR was the major release mechanism altered in epileptogenesis. These data indicate that both inhibition of SERCA and augmentation of CICR activity contribute to the alterations accounting for the impaired calcium homeostatic processes observed in 'epileptic' neurons. The results suggest that persistent changes in [Ca2+]i levels following epileptogenesis may contribute to the long-term plasticity changes manifested in epilepsy and that understanding the basic mechanisms mediating these changes may provide an insight into the development of novel therapeutic approaches to treat epilepsy and prevent or reverse epileptogenesis.

Discrimination of complete hydatidiform mole from its mimics by immunohistochemistry of the paternally imprinted gene product p57KIP2

The p57KIP2 protein is a cell cycle inhibitor and tumor suppressor encoded by a strongly paternally imprinted gene. We explored the utility of p57KIP2 as a diagnostic marker in hydatidiform mole, a disease likely the result of abnormal dosage and consequent misexpression of imprinted genes. Using a monoclonal antibody on paraffin-embedded, formalin-fixed tissue sections, the authors evaluated p57KIP2 expression in normal placenta and in 149 gestations including 59 complete hydatidiform moles, 39 PHMs, and 51 spontaneous losses with hydropic changes. p57KIP2 was strongly expressed in cytotrophoblast and villous mesenchyme in normal placenta, all cases of partial hydatidiform moles (39 of 39) and all spontaneous losses with hydropic changes (51 of 51). In contrast, p57KIP2 expression in cytotrophoblast and villous mesenchyme was absent or markedly decreased in 58 of 59 complete hydatidiform moles. In all gestations p57KIP2 was strongly expressed in decidua and in intervillous trophoblast islands, which served as internal positive controls for p57KIP2 immunostaining. p57KIP2 immunohistochemistry can reliably identify most cases of complete hydatidiform mole irrespective of gestational age and is thus a useful diagnostic adjunct, complementary to ploidy analysis, in the diagnosis of hydatidiform mole.

G-quadruplex DNA binding by a series of carbocyanine dyes

We have examined a number of carbocyanine dyes for their ability to bind intramolecular G-quadruplex DNA structures (G4'-DNA) using a Taq polymerase stop assay. Of the five dyes examined, only one, N,N'-diethylthiacarbocyanine iodide (DTC), was found to bind to G4'-DNA. DTC was also the only dye found to inhibit human telomerase at 50 microM concentration.

Active-site residues are critical for the folding and stability of methylamine dehydrogenase

Site-directed mutagenesis was used to alter active-site residues of methylamine dehydrogenase (MADH) from Paracoccus denitrificans. Four residues of the beta subunit of MADH which are in close proximity to the tryptophan tryptophylquinone (TTQ) prosthetic group were modified. The crystal structure of MADH reveals that each of these residues participates in hydrogen bonding interactions with other active-site residues, TTQ or water. Relatively conservative mutations which removed the potentially reactive oxygens on the side chains of Thr122, Tyr119, Asp76 and Asp32 each resulted in greatly reduced or undetectable levels of MADH production. The reduction of MADH levels was determined by assays of activity and Western blots of crude extracts with antisera specific for the MADH beta subunit. No activity or cross-reactive protein was detected in extracts of cells expressing D76N, T122A and T122C MADH mutants. Very low levels of active MADH were produced by cells expressing D32N, Y119F, Y119E and Y119K MADH mutants. The Y119F and D32N mutants were purified from cell extracts and found to be significantly less stable than wild-type MADH. Only the T122S MADH mutant was produced at near wild-type levels. Possible roles for these amino acid residues in stabilizing unusual structural features of the MADH beta subunit, protein folding and TTQ biosynthesis are discussed.

Effects of calorie restriction on polymicrobial peritonitis induced by cecum ligation and puncture in young C57BL/6 mice

Calorie restriction (CR) is known to prolong the life span and maintain an active immune function in aged mice, but it is still not known if rodents under CR can respond optimally to bacterial infection. We report here on the influence of CR on the response of peritoneal macrophages to lipopolysaccharide, splenic NF-kappaB and NF-interleukin-6 (IL-6) activities, and mortality in polymicrobial sepsis induced by cecal ligation and puncture (CLP). Macrophages from 6-month-old C57BL/6 mice on a calorie-restricted diet were less responsive to lipopolysaccharide, as evidenced by lower levels of IL-12 and IL-6 protein and mRNA expression. Furthermore, in vitro lipopolysaccharide-stimulated macrophages from mice under CR also expressed decreased lipopolysaccharide receptor CD14 levels as well as Toll-like receptor 2 (TLR2) and TLR4 mRNA levels. In addition, the phagocytic capacity and class II (I-A(b)) expression of macrophages were also found to be significantly lower in mice under CR. Mice under CR died earlier (P < 0.005) after sepsis induced by CLP, which appeared to be a result of increased levels in serum of the proinflammatory cytokines tumor necrosis factor alpha and IL-6 and splenic NF-kappaB and NF-IL-6 activation 4 h after CLP. However, mice under CR survived significantly (P < 0.005) longer than mice fed ad libitum when injected with paraquat, a free radical-inducing agent. These data suggest that young mice under CR may be protected against oxidative stress but may have delayed maturation of macrophage function and increased susceptibility to bacterial infection.

[Assessing health state utility using the short form 36]

OBJECTIVE

To explore the methods of utility assessment using the short form 36.

METHODS

The authors selected 70 people stratified by age, sex, and occupation in a city in Sichuan province, and investigated the preference of the population on each domain or item by paired comparison with other domains or items. Based on the preference, the weights of the domains and items were calculated.

RESULTS

The weights of all the 8 domains and the items within 7 domains except the first domain "physical functions" were identified. The total score and the scores of the domains calculated by weighted adding method were significantly different from those calculated by simple adding method. However, only little variation of the scores of the domains between the two methods appeared.

CONCLUSION

Utility calculated by weighted adding method may reflect people's preference to the health states more accurately. However, the value is limited in using weighted adding method for calculating the scores of domains.

Expression of Na(+)-K(+)-Cl(-) cotransporter in rat brain during development and its localization in mature astrocytes

Na(+)-K(+)-Cl(-) cotransporter has been proposed to play an important role in the regulation of intracellular Cl(-) concentration in neurons during development. In this study, the expression pattern of the cotransporter in different regions of rat brain was examined at birth (P0), postnatal days 7 (P7), P14, P21, and adult by Western blotting analysis. In cortex, thalamus, cerebellum and striatum, the cotransporter expression level was low at P0 and significantly increased at P14 (P<0.05). The expression peaked at P21 and was maintained at the same level in adulthood. However, in hippocampus, a peak level of the cotransporter expression was detected in adult brain. The immunocytochemistry study of adult rat brain revealed that an intense staining of the Na(+)-K(+)-Cl(-) cotransporter protein was observed in dendritic processes of CA1-CA3 hippocampal pyramidal neurons. In contrast, abundant immuno-reactive signals of the cotransporter were found in somata of thalamic nucleus. Immunofluorescence double staining demonstrates that the Na(+)-K(+)-Cl(-) cotransporter was expressed in astrocytes within cortex, corpus callosum, hippocampus and cerebellum. In addition, co-localization of the cotransporter and glial fibrillary acidic protein (GFAP), or with aquaporin 4, was found in perivascular astrocytes of cortical cortex and white matter. The results indicate that a time-dependent expression of the Na(+)-K(+)-Cl(-) cotransporter protein occurs not only in cortex but also in hippocampus, striatum, thalamus and cerebellum. In addition, the cotransporter is expressed in astrocytes and perivascular astrocytes of adult rat brain.

Mediation of tubuloglomerular feedback by adenosine: evidence from mice lacking adenosine 1 receptors

Adenosine is a determinant of metabolic control of organ function increasing oxygen supply through the A2 class of adenosine receptors and reducing oxygen demand through A1 adenosine receptors (A1AR). In the kidney, activation of A1AR in afferent glomerular arterioles has been suggested to contribute to tubuloglomerular feedback (TGF), the vasoconstriction elicited by elevations in [NaCl] in the macula densa region of the nephron. To further elucidate the role of A1AR in TGF, we have generated mice in which the entire A1AR coding sequence was deleted by homologous recombination. Homozygous A1AR mutants that do not express A1AR mRNA transcripts and do not respond to A1AR agonists are viable and without gross anatomical abnormalities. Plasma and urinary electrolytes were not different between genotypes. Likewise, arterial blood pressure, heart rates, and glomerular filtration rates were indistinguishable between A1AR(+/+), A1AR(+/-), and A1AR(-/-) mice. TGF responses to an increase in loop of Henle flow rate from 0 to 30 nl/min, whether determined as change of stop flow pressure or early proximal flow rate, were completely abolished in A1AR(-/-) mice (stop flow pressure response, -6.8 +/- 0.55 mmHg and -0.4 +/- 0.2 in A1AR(+/+) and A1AR(-/-) mice; early proximal flow rate response, -3.4 +/- 0.4 nl/min and +0.02 +/- 0.3 nl/min in A1AR(+/+) and A1AR(-/-) mice). Absence of TGF responses in A1AR-deficient mice suggests that adenosine is a required constituent of the juxtaglomerular signaling pathway. A1AR null mutant mice are a promising tool to study the functional role of A1AR in different target tissues.

Role of endothelial [Ca2+]i in activation of eNOS in pressurized arterioles by agonists and wall shear stress

In cultured endothelial cells, Ca2+-dependent and -independent activation of nitric oxide (NO) synthesis to agonists and flow/wall shear stress (WSS) has been demonstrated. However, the presence and function of these pathways are less well known in microvessels that can be exposed to a high level of WSS. We hypothesized that the role of changes in endothelial intracellular calcium concentration ([Ca2+]i) is different in agonist- and WSS-induced release of NO. Thus changes in endothelial [Ca2+]i and diameter of intact pressurized (approximately 100 microm at 80 mmHg) gracilis skeletal muscle arterioles of rats were measured by fluorescent videomicroscopy. Acetylcholine (ACh) and increases in WSS (by increasing intraluminal flow) elicited dilations (maximum 91 +/- 2% and 34 +/- 4%) that could be inhibited by N(omega)-nitro-L-arginine methyl ester (L-NAME), a NO synthase blocker. In diameter-clamped arterioles, ACh caused substantial increases in the endothelial calcium fluorescence ratio (ER(Ca), maximum 43 +/- 5%), which was significantly greater than changes in ER(Ca) (maximum approximately 10%) to increases in WSS. The Ca(2+) ionophore A-23187 also substantially increased ER(Ca) (maximum 38 +/- 5%) and elicited significant L-NAME-sensitive arteriolar dilations (maximum 45 +/- 7%). Intraluminal administration of the tyrosine kinase inhibitor genistein had no effect on dilations induced by ACh or the NO donor sodium nitroprusside, whereas it eliminated WSS-induced dilations. Collectively, our data suggest that, in endothelium of skeletal muscle arterioles, NO synthesis is activated by shear stress without a substantial increase in [Ca2+]i, most likely by activation of tyrosine kinase pathways, whereas NO release by ACh and A-23187 is associated with substantial increases in [Ca2+]i.

Interleukin-10 inhibits polymethylmethacrylate particle induced interleukin-6 and tumor necrosis factor-alpha release by human monocyte/macrophages in vitro

Periprosthetic membranes commonly observed at sites of total joint implant loosening exhibit abundant macrophages and particulate debris. Macrophages phagocytose orthopedic debris and release the pro-inflammatory mediators interleukin-1, interleukin-6, tumor necrosis factor-alpha, and prostaglandin E2. Populations of activated lymphocytes are often seen in periprosthetic membranes. These lymphocytes may modulate the monocyte/macrophage response to particulate debris and influence aseptic loosening. In addition, other immunologic agents, such as interleukin-10, are present in tissues harvested from the bone-implant interface of failed total joint arthroplasties. The present study examined the effects of interleukin-10 on polymethylmethacrylate (PMMA) particle challenged human monocyte/macrophages in vitro. Human monocyte/macrophages isolated from buffy coats of five healthy individuals were exposed to 1-10 microm PMMA particles. Interleukin-10 was added to the monocyte/macrophages with and without the addition of PMMA particles. Interleukin-10-induced alterations in monocyte/macrophage metabolism were determined measuring interleukin-6 and tumor necrosis factor-alpha release by the cells following exposure to PMMA particles. Exposure of the monocyte/macrophages to PMMA particles resulted in a dose-dependent release of interleukin-6 and tumor necrosis factor-alpha at 48 h. Interleukin-10 reduced the levels of interleukin-6 and tumor necrosis factor-alpha release by macrophages in response to PMMA particles in a dose-dependent manner. At 48 h, particle-induced interleukin-6 release was inhibited by 60 and 90% with 1.0 and 10.0 ng/ml treatments of interleukin-10, respectively. At 48 h, particle-induced tumor necrosis factor-alpha release was inhibited by 58 and 88% with 1.0 and 10.0 ng/ml treatments of interleukin-10, respectively. Interleukin-10 challenge alone did not significantly alter basal interleukin-6 or tumor necrosis factor-alpha release relative to control cultures. The data presented in this study demonstrate that the anti-inflammatory cytokine, interleukin-10, inhibits monocyte/macrophage release of the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in response to PMMA particle challenge in vitro.

[Intravesical instillation of cytotoxic T-lymphocytes induced by soluble tumor antigen in the prophylaxis of recurrence of bladder cancer]

OBJECTIVE

To explore a new method for preventing the recurrence of bladder cancer.

METHODS

With the adjuvant of BCG, cytotoxic T-lymphocytes (CTLs) were induced from human peripheral blood mononuclear cells (PBMC) by bladder tumor soluble antigen which was extracted through salt-infiltrating biochemical procedures from autologous bladder tumor. Intravesical instillation of CTLs together with their supernatants after culture for 8 to 10 days was performed in 37 patients with superficial bladder cancer after surgery. The effects of the treatment were evaluated by endocytoscopy, pathological examinations and ELISA assays for the levels of cytokines IL-2, TNF-alpha and IFN-gamma in the patients' serum and urine. The distribution of T-lymphocyte subpopulations was also monitored by SAP immuno-histochemical techniques.

RESULTS

The proportion of CD3+ and CD4+ T-lymphocyte subpopulations increased significantly while CD8+ T-lymphocyte subpopulation was stable. The ratio of CD4+ to CD8+ increased to 1.60 +/- 0.29. The levels of cytokines IL-2, TNF-alpha and IFN-gamma in serum and urine increased significantly, especially the level of TNF-alpha in urine. Pathological studies revealed that non-specific inflammation is the major change in the bladder mucosa after therapy. Follow-up for 6-26 months showed that 1 patient havd moderate heterogeneity in bladder mucosa. The recurrence rate was 2.7%. Side effects were not found except transient lower fever or hematuria.

CONCLUSION

Intravesical insitillation of CTLs could effectively prevent the recurrence of superficial bladder cancer after the improvement of immunological reactivity in the whole body.

Ki-67, cyclin E, and p16INK4 are complimentary surrogate biomarkers for human papilloma virus-related cervical neoplasia

Prior studies of Ki-67, cyclin E, and p16 expression have suggested that these biomarkers may be preferentially expressed in cervical neoplasia. This study examined and compared the distribution of staining for these three antigens in 1) normal and reactive epithelial changes, 2) diagnostically challenging cases (atypical metaplasia and atypical atrophy), 3) squamous intraepithelial lesions (SIL), and 4) high-and low-risk human papilloma virus (HPV) type-specific SIL. One hundred four epithelial foci from 99 biopsies were studied, including low-grade squamous intraepithelial lesions (LSIL; 24), high-grade squamous intraepithelial lesions (HSIL; 36), mature or immature (metaplastic) squamous epithelium (29), and atrophic or metaplastic epithelium with atypia (15). Cases were scored positive for Ki-67 expression if expression extended above the basal one third of the epithelium, for cyclin E if moderate to strong staining was present, and for p16 if moderate to strong diffuse or focal staining was present. HPV status was scored by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of extracted DNA. Immunohistochemical findings were correlated with histologic and viral data. Overall, a histologic diagnosis of SIL correlated strongly with all of the biomarkers used (p <0.001). Positive scores for Ki-67, cyclin E, and p16 were seen in 68.4%, 96.7%, and 100% of LSILs and 94.7%, 91.6%, and 100% of HSILs, respectively. Positive predictive values of these three biomarkers for HPV were 82.4%, 89.5%, and 91.4%, respectively. The positive predictive value for HPV of either cyclin E or p16 was 88.7%. Strong diffuse staining for p16 was significantly associated with high-risk HPV-associated lesions. Normal or reactive epithelial changes scored positive for the three biomarkers in 7.7%, 8.0%, and 12%, respectively. Limitations in specificity included minimal or no suprabasal staining for Ki-67 in immature condylomas and occasional suprabasal staining of reactive epithelial changes (10%), diffuse weak nuclear cyclin E staining in some normal or metaplastic epithelia, and diffuse weak basal p16 staining and occasional stronger focal positivity in normal epithelia. Ki-67, cyclin E, and p16 are complementary surrogate biomarkers for HPV-related preinvasive squamous cervical disease. (Because cyclin E and p16 are most sensitive for LSIL and HSIL [including high-risk HPV], respectively, use of these biomarkers in combination for resolving diagnostic problems, with an appreciation of potential background staining, is recommended.)

Myelin antigen-specific CD8+ T cells are encephalitogenic and produce severe disease in C57BL/6 mice

Encephalitogenic T cells that mediate experimental autoimmune encephalomyelitis (EAE) are commonly assumed to be exclusively CD4+, but formal proof is still lacking. In this study, we report that synthetic peptides 35-55 from myelin oligodendrocyte glycoprotein (pMOG(35-55)) consistently activate a high proportion of CD8+ alphabetaTCR+ T cells that are encephalitogenic in C57BL/6 (B6) mice. The encephalitogenic potential of CD8+ MOG-specific T cells was established by adoptive transfer of CD8-enriched MOG-specific T cells. These cells induced a much more severe and permanent disease than disease actively induced by immunization with pMOG(35-55). CNS lesions in pMOG(35-55) CD8+ T cell-induced EAE were progressive and more destructive. The CD8+ T cells were strongly pathogenic in syngeneic B6 and RAG-1(-/-) mice, but not in isogeneic beta2-microglobulin-deficient mice. MOG-specific CD8+ T cells could be repeatedly reisolated for up to 287 days from recipient B6 or RAG-1(-/-) mice in which disease was induced adoptively with <1 x 10(6) T cells sensitized to pMOG(35-55). It is postulated that MOG induces a relapsing and/or progressive pattern of EAE by eliciting a T cell response dominated by CD8+ autoreactive T cells. Such cells appear to have an enhanced tissue-damaging effect and persist in the animal for long periods.

EDHF mediates flow-induced dilation in skeletal muscle arterioles of female eNOS-KO mice

Vasodilation to increases in flow was studied in isolated gracilis muscle arterioles of female endothelial nitric oxide synthase (eNOS)-knockout (KO) and female wild-type (WT) mice. Dilation to flow (0-10 microl/min) was similar in the two groups, yet calculated wall shear stress was significantly greater in arterioles of eNOS-KO than in arterioles of WT mice. Indomethacin, which inhibited flow-induced dilation in vessels of WT mice by approximately 40%, did not affect the responses of eNOS-KO mice, whereas miconazole and 6-(2-proparglyoxyphenyl)hexanoic acid (PPOH) abolished the responses. Basal release of epoxyeicosatrienonic acids from arterioles was inhibited by PPOH. Iberiotoxin eliminated flow-induced dilation in arterioles of eNOS-KO mice but had no effect on arterioles of WT mice. In WT mice, neither N(omega)-nitro-L-arginine methyl ester nor miconazole alone affected flow-induced dilation. Combination of both inhibitors inhibited the responses by approximately 50%. 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) alone inhibited flow-induced dilation by approximately 49%. ODQ + indomethacin eliminated the responses. Thus, in arterioles of female WT mice, nitric oxide and prostaglandins mediate flow-induced dilation. When eNOS is inhibited, endothelium-derived hyperpolarizing factor substitutes for nitric oxide. In female eNOS-KO mice, metabolites of cytochrome P-450, via activation of large-conductance Ca2+-activated K+ channels of smooth muscle, mediate entirely the arteriolar dilation to flow.

[Effects of the alterations of membrane shear elastic modulus and viscosity on the deformation and orientation of RBCs]

Neuraminidase can partly remove the surface charge of RBCs through a biochemical interaction; thus it can give rise to alterations in the microstructure of membrane, the shear elastic modulus (E) and the viscosity(micron) of membrane. Changing the time of treatment and the dose of neuraminidase and using a new ektacytometry that can separate deformation index DI into orientation index (DI)or and small deformation index (DI)d for RBCs in shear flow field of low viscosity, we measured (DI)d and the half time t0.5 when the DI recovered to half of the maximum in the process of relaxation for every treated sample. (DI)d and t0.5 were put respectively into the RBC membrane shear elastic modulus formula and the membrane viscosity formula which were put forward by Wen Zong-yao and Yan Zong-yi et al[1]. The rules of the alterations of E and micron were obtained. We also measured DI and (DI)or. It was found that E and micron increased greatly but DI and (DI)or decreased when the dose of neuraminidase and the time of treatment were increased. There was a contrary correlation between them. These data demonstrated that the increase of E and micron weakened the deformability and the ability of orientation of RBCs.

Gender-specific compensation for the lack of NO in the mediation of flow-induced arteriolar dilation

Flow-induced dilation of gracilis muscle arterioles was examined in both genders of control rats and rats chronically treated with N ω-nitro-l-arginine methyl ester (l-NAME). After l-NAME treatment (4 wk), systolic blood pressure was significantly increased compared with control, whereas the plasma concentration of nitrate/nitrite was significantly reduced. Isolated and pressurized arterioles dilated significantly in response to increases in flow (0–25 μl/min). Flow-induced dilation was comparable in arterioles of control andl-NAME-treated rats but was significantly greater in female than in male rats. l-NAME + indomethacin, which abolished flow-induced dilation in arterioles of male control rats, inhibited the dilation by only ∼75% in female control rats. The residual portion of the response was eliminated by additional administration of miconazole, an inhibitor of cytochrome P-450. Indomethacin did not affect the dilation in femalel-NAME-treated rats but completely inhibited the response in male l-NAME-treated rats. The indomethacin-insensitive, flow-induced dilation in female l-NAME-treated arterioles was abolished by miconazole, 6-(2-proparglyoxyphenyl)hexanoic acid, or charybdotoxin. Thus an augmented release of endothelial prostaglandins accounts for the preserved flow-induced dilation in arterioles of male rats, whereas a metabolite of cytochrome P-450 is responsible for the maintenance of flow-induced dilation in female rats, suggesting important differences in the adaptation of the endothelium of arterioles from male and female rats to the lack of nitric oxide (NO) synthesis.