Aspirin treatment of the low-dose-endotoxin-treated pregnant rat: pathophysiologic and immunohistologic aspects

In the present study, we evaluated the effect of low-dose aspirin (acetylsalicylic acid (ASA); 1.0 mg/kg daily) on blood pressure, albumin excretion, glomerular fibrinogen deposits, and glomerular (basement) membrane-bound adenosine diphosphatase (ecto-ADPase) activity, as well as on glomerular inflammation in pregnant rats infused with low-dose endotoxin (1.0 mg/kg). Rats (day 14 of pregnancy) were infused with endotoxin (ET rats) or saline (control rats) and received ASA in their drinking water. These rats were compared with non-ASA-treated rats. Blood pressure and albumin excretion were measured from day 15 to day 21, and glomerular fibrinogen and ecto-ADPase activity were measured at day 21. Glomerular inflammation was evaluated at various times after the start of the infusion. The results show that treatment with ASA had a significant beneficial effect on hypertension and inflammation induced by endotoxin in pregnant rats, whereas it reduced albumin excretion and glomerular fibrinogen deposits in some of the rats.     

Fine mapping of the hereditary sensory neuropathy type I locus on chromosome 9q22.1-->q22.3: exclusion of GAS1 and XPA

BACKGROUND: Knowledge about the natural course of HPV infection is still limited. In this study we investigated the presence of HPV DNA after treatment and clinical clearance of infection. METHODS: Eighty-two women treated for genital HPV infection at the STD clinic in Uppsala were consecutively selected for the study. After treatment with podophyllotoxin, and in some cases laser vaporization, a cell sample was taken at the follow-up visit 6-12 months after clinical clearance of the lesions as evaluated by colposcopy. Samples were analysed with PCR to detect HPV DNA. As a reference group, women treated for cervical intraepithelial neoplasia (CIN) with laser surgery, either with cone biopsy or vaporization, were followed-up after 6 months for the presence of HPV DNA. RESULTS: Six to 12 months after clinical clearance of HPV infection, 39 (48%) of the women showed detectable HPV DNA in cell samples from the cervix. Of these, 26 (67%) were found to harbor high risk HPV, six (15%) low risk, and seven (18%) either had more than one HPV type or HPV that could not be classified. All but three of the women treated for CIN (90%) were negative for HPV DNA. CONCLUSION: After clinical clearance of genital HPV infection half of the women had detectable HPV DNA. This does not necessarily imply that transmission to a new partner may occur, but indicates this possibility. Only 10% of the CIN treated women harbored HPV DNA in the cell samples in spite of showing high risk HPV infection before treatment.     

Effects of prior exercise on exercise-induced arterial hypoxemia in young women

Insulin-like growth factor binding proteins (IGFBP) proteases have been proposed to be involved in changes of serum IGFBP pattern during pregnancy. IGFBP-4 and -5 are degraded specifically by proteases in pregnancy serum in vitro, whereas IGFBP-3 proteolytic activity was also detected in nonpregnancy serum. To identify and characterize IGFBP proteases, human pregnancy serum was fractionated by size exclusion chromatography revealing IGFBP-4 protease activities in fractions coeluting with proteins of approximately 600-kDa and 50- to 100-kDa molecular mass. In both fractions, a predominant 50-kDa gelatinase was found, suggesting that parts of the gelatinase activity might aggregate or are complexed with other proteins forming a higher molecular complex. Hydroxyapatite chromatography and chromatofocusing of the 50- to 100-kDa serum fraction showed that the IGFBP-4 protease and the 50-kDa gelatinase activity were copurified. When the 50-kDa gelatinase-containing band was excised from the polyacrylamide gel, it exhibited IGFBP-4 proteolytic activity, resulting in the formation of 17- and 10-kDa fragments. [125I] IGFBP substrate zymography combined with fragment blotting showed that the 1,10-phenanthroline-sensitive 50-kDa protease activity purified by chromatofocusing also cleaved IGFBP-3 and -5. Other proteases detected in pregnancy serum fractions with Mr estimates of 79-, 30-, and 22-kDa degraded IGFBP-3 and -5 but not IGFBP-4. [125I] IGFBP-5 substrate zymography revealed that the 30-kDa IGFBP protease was inhibited by serine protease inhibitors. Whereas 1,10-phenanthroline inhibited the IGFBP proteolytic activity in the solution assay, serine protease inhibitors failed to affect proteolysis, indicating the predominant contribution of the metalloproteinase to IGFBP proteolysis. Tissue inhibitors of matrix metalloproteinases-1 and -2 revealed weak or no inhibition of IGFBP-4 and -5 proteolytic activity, whereas a hydroxamic acid-based inhibitor, potentially inhibiting disintegrin metalloproteases, completely prevented the proteolysis of IGFBPs. Whereas no specific immunoreactivity of the 50-kDa protein with antimatrix metalloproteinase-1, -2, -3, -9, or -13 antibodies was observed, antidisintegrin domain-specific antibodies bound to the 50-kDa gelatinase. These studies provide the first direct biochemical evidence that human pregnancy serum contains a 50-kDa IGFBP protease with properties of a soluble disintegrin metalloproteinase that appears to be potentially involved in regulating IGF bioavailability for placental and fetal growth.     

Interleukin 12 and B7-1 costimulatory molecule expressed by an adenovirus vector act synergistically to facilitate tumor regression

Stimulation of antitumor immune mechanisms is the primary goal of cancer immunotherapy, and accumulating evidence suggests that effective alteration of the host-tumor relationship involves immunomodulating cytokines and also the presence of costimulatory molecules. To examine the antitumor effect of direct in vivo gene transfer of murine interleukin 12 (IL-12) and B7-1 into tumors, we developed an adenovirus (Ad) vector, AdIL12-B7-1, that encodes the two IL-12 subunits in early region 1 (E1) and the B7-1 gene in E3 under control of the murine cytomegalovirus promoter. This vector expressed high levels of IL-12 and B7-1 in infected murine and human cell lines and in primary murine tumor cells. In mice bearing tumors derived from a transgenic mouse mammary adenocarcinoma, a single intratumoral injection with a low dose (2.5 x 10(7) pfu/mouse) of AdIL12-B7-1 mediated complete regression in 70% of treated animals. By contrast, administration of a similar dose of recombinant virus encoding IL-12 or B7-1 alone resulted in only a delay in tumor growth. Interestingly, coinjection of two different viruses expressing either IL-12 or B7-1 induced complete tumor regression in only 30% of animals treated at this dose. Significantly, cured animals remained tumor free after rechallenge with fresh tumor cells, suggesting that protective immunity had been induced by treatment with AdIL12-B7-1. These results support the use of Ad vectors as a highly efficient delivery system for synergistically acting molecules and show that the combination of IL-12 and B7-1 within a single Ad vector might be a promising approach for in vivo cancer therapy.     

Requirement for both Shc and phosphatidylinositol 3' kinase signaling pathways in polyomavirus middle T-mediated mammary tumorigenesis

Transgenic mice expressing the polyomavirus (PyV) middle T antigen (MT) develop multifocal mammary tumors which frequently metastasize to the lung. The potent transforming activity of PyV MT is correlated with its capacity to activate and associate with a number of signaling molecules, including the Src family tyrosine kinases, the 85-kDa Src homology 2 subunit of the phosphatidylinositol 3' (PI-3') kinase, and the Shc adapter protein. To uncover the role of these signaling proteins in MT-mediated mammary tumorigenesis, we have generated transgenic mice that express mutant PyV MT antigens decoupled from either the Shc or the PI-3' kinase signaling pathway. In contrast to the rapid induction of metastatic mammary tumors observed in the strains expressing wild-type PyV MT, mammary epithelial cell-specific expression of either mutant PyV MT resulted in the induction of extensive mammary epithelial hyperplasias. The mammary epithelial hyperplasias expressing the mutant PyV MT defective in recruiting the PI-3' kinase were highly apoptotic, suggesting that recruitment of PI-3' kinase by MT affects cell survival. Whereas the initial phenotypes observed in both strains were global mammary epithelial hyperplasias, focal mammary tumors eventually arose in all female transgenic mice. Genetic and biochemical analyses of tumorigenesis in the transgenic strains expressing the PyV MT mutant lacking the Shc binding site revealed that a proportion of the metastatic tumors arising in these mice displayed evidence of reversion of the mutant Shc binding site. In contrast, no evidence of reversion of the PI-3' kinase binding site was noted in tumors derived from the strains expressing the PI-3' kinase binding site MT mutant. Tumor progression in both mutant strains was further correlated with upregulation of the epidermal growth factor receptor family members which are known to couple to the PI-3' kinase and Shc signaling pathways. Taken together, these observations suggest that PyV MT-mediated tumorigenesis requires activation of both Shc and PI-3' kinase, which appear to be required for stimulation of cell proliferation and survival signaling pathways, respectively.     

Linking postdoctoral general dentistry programs with managed care programs and settings

Sleep-disordered breathing is a chronic problem of the inappropriate mechanical collapse of the upper airway. Symptoms range from mild occasional snoring to severe obstructive sleep apnea. The standard of care for the diagnosis and treatment of sleep-disordered breathing by sleep medicine has been the use of the polysomnogram and continuous positive airway pressure. This approach is burdensome, costly, and ineffective due to lack of compliance with or rejection of treatment. Oral appliances are highly effective in managing the mild snorer to the moderate sleep apneic and are approaching the efficacy of continuous positive airway pressure with the severe apneic. The dentist can and should manage these patients. However, the dental practitioner must acquire sufficient training and knowledge to appropriately treat these patients.     

Role of estrogen receptor gene demethylation and DNA methyltransferase.DNA adduct formation in 5-aza-2'deoxycytidine-induced cytotoxicity in human breast cancer cells

The cytosine analog 5-aza-2'-deoxycytidine is a potent inhibitor of DNA methyltransferase. Its cytotoxicity has been attributed to several possible mechanisms including reexpression of growth suppressor genes and formation of covalent adducts between DNA methyltransferase and 5-aza-2'-deoxycytidine-substituted DNA which may lead to steric inhibition of DNA function. In this study, we use a panel of human breast cancer cell lines as a model system to examine the relative contribution of two mechanisms, gene reactivation and adduct formation. Estrogen receptor-negative cells, which have a hypermethylated estrogen receptor gene promoter, are more sensitive than estrogen receptor-positive cells and underwent apoptosis in response to 5-aza-2'-deoxycytidine. For the first time, we show that reactivation of a gene silenced by methylation, estrogen receptor, plays a major role in this toxicity in one estrogen receptor-negative cell line as treatment of the cells with anti-estrogen-blocked cell death. However, drug sensitivity of other tumor cell lines correlated best with increased levels of DNA methyltransferase activity and formation DNA.DNA methyltransferase adducts as analyzed in situ. Therefore, both reexpression of genes like estrogen receptor and formation of covalent enzyme. DNA adducts can play a role in 5-aza-2'-deoxycytidine toxicity in cancer cells.     

Model for a one-step plasma treatment device: feasibility of cholesterol removal

A self-contained plasmapheresis device based on Starling flow has been proposed. A computer model was developed to describe the device performance, and a device using conventional cellulose tri-acetate (CTA) fibers was modeled. Predicted pressure drops and ultrafiltration flow agreed well with measurements using bovine blood in prototype devices made with CTA fibers. The model predicted the expected Starling flow and predicted the observed high hematocrit region near the fiber wall and a layer of packed red cells on the wall. Typically, 15% of the ultrafiltration flow occurred in the first 2-3% of the fiber length where no packed cell layer was present. The entrance header was predicted to cause lower blood pressures in the peripheral fibers, producing a net plasma migration from the central to the peripheral fibers. As an example application for this device, the computer model was used to assess the feasibility of reducing LDL-cholesterol in patients. The use of sequential 1 hour treatments by a modified device was predicted to reduce the cholesterol in a standard man from 200 mg% to 150 mg% in less than 3 hours.     

Surface carbohydrates involved in the adhesive interactions of metastatic cells

Extracellular proteases can trigger intracellular events via at least two members of the super-family of G protein coupled receptors: the thrombin receptor and PAR-2. The two receptors have a similar structure, share a common mechanism of activation and may have arisen by gene duplication, but there are differences as well as similarities in their tissue distribution, the proteases by which they are activated and potentially in the consequences of their activation. Human platelets express the thrombin receptor, but not PAR-2, while at least some types of human endothelial cells express both. This review briefly summarizes current information about the two receptors and considers their roles in platelet and endothelial cell biology, their interactions with proteases, and the known mechanisms for receptor redistribution and replacement.