Intracranial microdialysis of salicylic acid to detect hydroxyl radical generation through dopamine autooxidation in the caudate nucleus: effects of MPP+

Ringer's solution containing salicylic acid (5 nmol/microliters/min) was infused directly through an intracranial microdialysis probe to detect the generation of hydroxyl radicals (.OH) reflected by the formation of dihydroxybenzoic acids (DHBA) in the caudate nucleus of anesthetized rats. Brain dialysate was assayed for dopamine, 2,3-, and 2,5-DHBA by a high-pressure liquid chromatography-electrochemical (HPLC-EC) procedure. 1-Methyl-4-phenylpyridinium ions (MPP+, 0 to 150 nmol) increased dose-dependently the release of dopamine and the formation of DHBA. A positive linear correlation between the release of dopamine and the formation of 2,3- or 2,5-DHBA was observed (R2 = .98). The present results demonstrate the validity of the use of not only 2,3-DHBA but also 2,5-DHBA as an in vivo index of oxidative damage generated by reactive .OH radicals. In conclusion, the present study demonstrates a novel use of intracranial microdialysis of salicylic acid to assess the oxidative damage elicited by .OH in living brain.

Fusarium polycaprolactone depolymerase is cutinase

Polycaprolactone (PCL), a synthetic polyester, is degraded by a variety of microorganisms, including some phytopathogens. Many phytopathogens secrete cutinase, a serine hydrolase that degrades cutin, the structural polymer of the plant cuticle. We compared wild-type strains and a cutinase-negative gene replacement mutant strain of Fusarium solani f. sp. pisi (D. J. Stahl and W. Schäfer, Plant Cell 4:621-629, 1992) and a wild-type strain of Fusarium moniliforme to show that Fusarium cutinase is a PCL depolymerase. The wild-type strains, but not the mutant strain, (i) degraded PCL and used it as a source of carbon and energy, (ii) showed induction of secreted PCL depolymerase and an esterase activity of cutinase when grown in the presence of cutin, and (iii) showed induction of PCL depolymerase and an esterase activity of cutinase when grown in the presence of a hydrolysate of PCL, which contains PCL oligomers that are structurally similar to the natural inducers of cutinase. These results together with other details of regulation and conditions for optimal enzyme activity indicate that the Fusarium PCL depolymerase, required for degradation and utilization of PCL, is cutinase.

Incidence and mortality of nasopharyngeal carcinoma: interim analysis of a cluster randomized controlled screening trial (PRO-NPC-001) in southern China

BACKGROUND

Previous mass screening studies have shown that IgA antibodies against Epstein-Barr Virus (EBV) can facilitate early detection of nasopharyngeal carcinoma (NPC), but the impact of EBV-antibody screening for NPC-specific mortality remains unknown.

PATIENTS AND METHODS

A prospective, cluster randomized, controlled trial for NPC screening (PRO-NPC-001) was conducted in 3 selected towns of Zhongshan City and 13 selected towns of Sihui City in southern China beginning in 2008. Serum samples of the screening group were tested for two previously selected anti-EBV antibodies. Subjects with serological medium risk were subsequently retested annually for 3 years, and those with serological high risk were referred to otorhinolaryngologists for diagnostic check-up. An interim analysis was carried out to evaluate the primary end points of the NPC-specific mortality and the early diagnostic rate, and the secondary end point of the NPC incidence, through linkage with the database of Zhongshan City.

RESULTS

Among 70 296 total subjects, 29 413 screened participants (41.8% of the total subjects) in the screening group and 50 636 in the control group, 153 (43.3 per 100 000 person-year), 62 (55.3 per 100 000 person-year) and 99 (33.1 per 100 000 person-year) NPC cases were identified. The early diagnostic rates of NPC were significantly higher in the participants (79.0%, P < 0.0001) and the screening group (45.9%, P < 0.0001) compared with the control group (20.6%). Although no differences were found between NPC-specific mortality of the screening group and the control group [relative risk (RR)= 0.82, 95% confidence interval (CI) 0.37-1.79], lower NPC-specific mortality was noticed among participants from the screening group versus the control group (RR = 0.22, 95% CI 0.09-0.49).

CONCLUSION

IgA antibodies against EBV can identify high-risk population and was effective in screening for early asymptomatic NPC. Although the mortality reduction was not significant in the primary end point, we noted encouraging evidence of a mortality reduction in screening participants in this interim analysis.

CLINICAL TRIAL NUMBER

NCT00941538.

Adenovirus-mediated p21((WAF1/SDII/CIP1)) gene transfer induces apoptosis of human cervical cancer cell lines

p21((WAF1/SDII/CIP1)) (p21) arrests cell growth by inhibiting cyclin-depend kinases. To explore the potential of using p21 for the gene therapy of cervical cancer, we infected human papillomavirus (HPV)-positive cervical cancer cells (HeLa, SiHa, and Z172) and HPV-negative cervical cancer cells (C33A) with recombinant adenovirus encoding p21 cDNA. The results revealed that effective inhibition of cell growth could be achieved by sense p21 adenovirus but not antisense p21 adenovirus infection and occurred through apoptosis as measured by DNA fragmentation and chromatin condensation. Apoptosis was also observed in xenografts of human cervical cancer cells infected with sense p21 adenovirus, as confirmed by in situ terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL). The apoptosis was not prevented by overexpression of the bcl-2 transgene. To sum up, the apoptotic effect suggests that p21 should be a tumoricidal agent instead of a tumoristatic agent in preventing cervical cancers. In addition, our report substantiates the combination of the high efficiency of adenovirus vector-mediated gene delivery and the apoptotic effect of p21.

Pre-eclampsia is associated with dendritic cell recruitment into the uterine decidua

Pre-eclampsia is a leading cause of fetal and maternal morbidity and mortality that preferentially affects primiparous patients. It is associated with systemic inflammation and impaired trophoblast invasion of the decidua. Decidual cells are the major cell type of the pregnant endometrium. Macrophages and dendritic cells are major specialized antigen-presenting cells that promote both innate immunity and immune tolerance. Macrophage infiltration is implicated in impaired trophoblast invasion that leads to pre-eclampsia. By contrast, the potential modulating role of decidual dendritic cells in the genesis of pre-eclampsia has not been investigated. Interleukin-1beta (IL-1beta), a pro-inflammatory cytokine, has been implicated in the genesis of pre-eclampsia. Thus, we postulate that pre-eclampsia would be associated with enhanced decidual dendritic cells infiltration and that IL-1beta would enhance the production of relevant dendritic cell-recruiting chemokines. We used immunohistochemistry to demonstrate a marked infiltrate of immature and mature dendritic cells in pre-eclamptic decidua. Further, immunohistochemistry and immunoassays of placental bed biopsies revealed that pre-eclamptic decidua displays elevated levels of several monocyte- and dendritic cell-recruiting chemokines. Leukocyte-free first-trimester decidual cells were then treated with IL-1beta, which enhanced the mRNA and protein expression of these chemokines. The current study also confirmed previous reports that macrophages directly impaired trophoblast invasion and that this inhibitory effect is augmented by the conditioned medium of IL-1beta-treated first-trimester decidual cells. However, unlike macrophages, dendritic cells did not directly impede trophoblast invasion. This study demonstrates that the inflammatory milieu of pre-eclampsia induces decidual cells to promote dendritic cell infiltration. Given their unusual versatility in mediating both immunity and tolerance, these novel findings suggest that dendritic cells may play a critical role either in the pathogenesis of pre-eclampsia or its prevention in subsequent pregnancies.

Interleukin 3 stimulates proliferation via protein kinase C activation without increasing inositol lipid turnover

Interleukin 3 (IL-3) is required for the survival and proliferation of the FDCP-Mix 1 multipotent stem cell line. IL-3 or phorbol esters can rapidly translocate protein kinase C from a cytosolic to a membrane-bound form in these cells. Phorbol esters were able to partially replace the requirement of FDCP-Mix 1 cells for IL-3. Down-modulation of protein kinase C levels by chronic treatment with phorbol ester markedly reduced the ability of the cells to proliferate in response to either IL-3 or phorbol esters. These data indicate that IL-3 can activate protein kinase C, leading to the survival and proliferation of stem cells. Protein kinase C is activated conventionally by complexing with diacylglycerol which accumulates in the cell membrane after agonist-stimulated hydrolysis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2]. However, there was no detectable breakdown of PtdIns(4,5)P2 when IL-3 was added to FDCP-Mix 1 cells, nor was there detectable accumulation of inositol phosphates in response to IL-3. In contrast, rapid hydrolysis of PtdIns(4,5)P2 and accumulation of inositol 1,4,5-trisphosphate was elicited by readdition of horse serum to serum-starved cells, thus indicating that these cells possess the necessary machinery to undergo agonist-mediated inositol phospholipid breakdown. We conclude that the mechanism whereby IL-3 can activate protein kinase C leading to proliferation is not associated with inositol phospholipid hydrolysis.

Synthesis and characterization of a new interpenetrated poly(2-hydroxyethylmethacrylate)-gelatin composite polymer

Poly(2-hydroxyethylmethacrylate) [poly(HEMA)] is a widely used biomaterial which does not allow cell adhesion and growth on its surface, limiting its use in biomedical applications in which cell cohesion is detrimental. We have prepared a poly(HEMA)-gelatin composite hydrogel using a sequential interpenetrating polymer network technique. The properties of this material were compared with poly(HEMA) freeze-dried sponges in terms of morphology, mechanical properties and biocompatibility. Moreover, in vivo biocompatibility experiments highlighted the occurrence of cellular interactions on the surface of the poly(HEMA)-gelatin interpenetrating polymer network, which are usually absent when unmodified poly(HEMA) hydrogels are implanted in the same host organism. These tests also showed a progressive gelatin degradation from the surface to the bulk of the poly(HEMA)-gelatin specimens during short-term (7 d) implantation. Finally, in vitro tests confirmed an improved ability of this composite to scaffold for the cells.

The expression of HPV-16 E5 protein in squamous neoplastic changes in the uterine cervix

To investigate the expression of human papillomavirus type 16 (HPV-16) E5 protein in squamous neoplastic changes in the uterine cervix, the specific E5 antibody was generated and used to identify the expression of E5 protein in 40 cases of HPV-16-positive tissues and 5 previously identified HPV-negative normal cervical tissues. The results revealed that E5 protein was primarily expressed in the lower third of the epithelium in low-grade squamous intraepithelial lesions (SILs) and throughout the whole epithelium in high-grade SILs. In invasive squamous carcinoma, 60% of HPV-16-infected cancers which contained the episomal viral genome had the E5 gene, and could express E5 protein which was located throughout the whole epithelium. Previously, we documented the expression of type I growth factor receptors [ERBB1/EGFR (epidermal growth factor receptor), ERBB2, ERBB3 and ERBB4] in the full range of cervical neoplasias by immunohistochemistry assay. Hence, in this study, we extensively analyzed the correlation between the expression of E5 protein and the expression of type I growth factor receptors. Among 40 HPV-16- infected cervical neoplasias, we found that the expression of E5 protein was significantly correlated with either the expression of the ERBB1 or the ERBB4 receptor.

Increased B-type natriuretic peptide (BNP) level is a strong predictor for cardiac dysfunction in intensive care unit patients

Patients admitted to an Intensive Care Unit (ICU) frequently have underlying cardiac dysfunction. Early interventions are sometimes difficult to initiate because of diagnostic uncertainty as to whether cardiac failure is present As B-type natriuretic peptide (BNP) has been shown to be increased in cardiac dysfunction, we sought to demonstrate whether BNP can be used as a screening tool for cardiac dysfunction in patients admitted to ICU. All patients admitted to a combined medical and surgical ICU over a four-week period were included in the study. BNP was measured on the point of admission using a hand-held meter. Clinicians were blinded from the measurement when diagnoses were made as to whether or not the patients had clinically significant cardiac dysfunction. Patients with cardiac dysfunction had a significantly higher level of BNP when compared to the non-cardiac dysfunction group: 516 +/- 385 pg/ml (n = 26) v 67 +/- 89 pg/ml (n = 58) (P < 0.0001) A BNP cut-off value at 144 pg/ml exhibited a 92% sensitivity, 86% specificity and 96% negative predictive value. The sensitivity improved to 96% when the analysis was confined to patients > or = 55 years. At this cut-off value, BNP is a strong predictor of cardiac dysfunction. BNP measurement offers a rapid and affordable way to screen for cardiac dysfunction in patients admitted to ICU. An increased BNP level warrants further cardiac investigations so as to implement early interventions for cardiac decompensation in ICU patients.

Regulation of chemokine production in response to pro-inflammatory cytokines in first trimester decidual cells

OBJECTIVE

Chemokines initiate the immune response by controlling leukocyte migration and lymphocyte development. Macrophage infiltration of the decidua has been implicated in the genesis of recurrent miscarriage and preeclampsia. Therefore, we determined whether cultured human decidual cells produce monocyte/macrophage-recruiting chemokines in response to a potent pro-inflammatory cytokine, interleukin-1beta (IL-1beta), and whether decidual cell-conditioned medium contains monocyte- and macrophage-chemoattractant activity.

METHODS

Leukocyte-free first trimester decidual cells were treated for 6h with estradiol (E(2)) and medroxyprogesterone acetate (MPA) to mimic the steroidal milieu of pregnancy, or E(2) and MPA and IL-1beta (1 ng/ml) to mimic inflamed decidua. Total RNA was used for cDNA synthesis. Biotinylated cRNAs were generated and chemically fragmented for hybridization on Affymetrix HG_U133 Plus 2.0 chips followed by fluorescence labeling and optical scanning. Raw data generated from Affymetrix GCOS 1.2 (GeneChip Operating Software) were analyzed by GeneSpring 7.2 software. Subsequently microarray results were validated by real time RT-PCR and Western blotting. A functional study of monocyte migration was carried out also using conditioned media from culture.

RESULTS

Five chemokines responsible for monocyte/macrophage chemoattraction and activation, including C-C motif ligand 2 (CCL2), CCL5, C-X-C motif ligand 2 (CXCL2), CXCL3 and CXCL8, were markedly elevated from 29- to 975-fold after exposure to IL-1beta in cultured first trimester decidual cells. The results of real-time RT-PCR (up-regulation from 43- to 3069-fold) and Western blotting (up-regulation from 15- to 300-fold) confirmed the microarray findings. Monocyte migration was significantly induced by the conditioned medium from IL-1beta-treated decidual cells.

CONCLUSIONS

Treatment of first trimester decidual cells with IL-1beta induces secretion of monocyte/macrophage recruiting-chemokines and promotes monocyte migration. Extrapolation of these in vitro results to the milieu of implantation site suggests a mechanism whereby IL-1beta could mediate excessive macrophage infiltration of the decidua.

Enhanced hydroxyl radical generation by 2'-methyl analog of MPTP: suppression by clorgyline and deprenyl

Sodium salicylate was infused through a microdialysis probe placed in the striatum of anesthetized rats in order to assay the formation of hydroxyl radical (.OH) in the extracellular fluid in vivo. In addition to causing sustained dopamine release, intrastriatal infusion of the 2'-methyl analog of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (2'CH3-MPTP) increased the formation of 2,3-dihydroxybenzoic acid (2,3-DHBA), the nonenzymatic .OH adduct of salicylate in the brain dialysate. Inhibition of monoamine oxidase (MAO) by clorgyline and deprenyl completely blocked the formation of 2,3-DHBA and the sustained dopamine overflow induced by 2'-CH3-MPTP. The results indicate that the enhanced formation of cytotoxic .OH by 2'-CH3-MPTP is suppressed by MAO inhibitors. These data support the hypothesis that the protective effect of MAO inhibitors on the neurotoxicity induced by MPTP analogues may be due not only to the inhibition of MPTP metabolism by MAO but also the blockade of the formation of .OH free radicals. An enhanced generation of cytotoxic .OH free radicals in the striatum which in turn leads to oxidant damage may be relevant to the development of parkinsonism-like changes in animals produced by MPTP analogues.

Induction of CD8 T cells by vaccination with recombinant adenovirus expressing human papillomavirus type 16 E5 gene reduces tumor growth

The potential of the E5 protein as a tumor vaccine candidate has not been explored yet. In this study, we evaluate the human papillomavirus type 16 (HPV-16) E5 protein delivered by an adenovirus vector as a tumor vaccine for cervical lesions. The results demonstrate that a single intramuscular injection of a recombinant adenovirus carrying the HPV-16 E5 gene into syngeneic animals can reduce the growth of tumors which contain E5 gene expression. Moreover, the E5 vaccine-induced tumor protection occurs through CD8 T cells but not through CD4 T cells in in vitro assays. In addition, our studies using knockout mice with distinct T-cell deficiencies confirm that cytotoxic T-lymphocyte-induced tumor protection is CD8 dependent but CD4 independent. Hence, HPV-16 E5 can be regarded as a tumor rejection antigen.

Platelet-activating factor-induced hydrolysis of phosphatidylinositol 4,5-bisphosphate stimulates the production of reactive oxygen intermediates in macrophages

To investigate the relationship between inositol lipid hydrolysis and reactive oxygen-intermediate (ROI) production in macrophages we have examined the effect of platelet-activating factor (PAF) on normal bone marrow-derived macrophages. Addition of PAF to macrophages prelabelled with [3H]inositol caused a marked and rapid increase in [3H]inositol trisphosphate levels. Similarly when PAF was added to [3H]-glycerol prelabelled macrophages there was a rapid increase in 1,2-diacyl[3H]glycerol levels. These events preceded any increase in the rate of PAF-stimulated ROI production by a discernible period of several seconds. Increasing concentrations of PAF led to a markedly similar increase in both ROI production and [3H]inositol lipid hydrolysis suggesting that inositol lipid hydrolysis may lead to the generation of ROI in macrophages. Further evidence that this is the case came from experiments in which pretreatment of macrophages with phorbol esters was shown to inhibit both PAF-stimulated [3H]inositol phosphate production and ROI production to a markedly similar degree. Similarly pertussis toxin inhibited both PAF-stimulated ROI production and [3H]inositol phosphate production. Phorbol esters were shown to activate ROI production in normal bone marrow-derived macrophages whereas the Ca2+ ionophore, A23187, did not. These experiments suggest that PAF stimulates a pertussis toxin-sensitive activation of inositol lipid hydrolysis leading to the formation of inositol trisphosphate and diacylglycerol. The diacylglycerol formed can then activate protein kinase C leading to the stimulation of ROI production in normal bone marrow-derived macrophages.

Workplace smoking related absenteeism and productivity costs in Taiwan

OBJECTIVE

To estimate productivity losses and financial costs to employers caused by cigarette smoking in the Taiwan workplace.

METHODS

The human capital approach was used to calculate lost productivity. Assuming the value of lost productivity was equal to the wage/salary rate and basing the calculations on smoking rate in the workforce, average days of absenteeism, average wage/salary rate, and increased risk and absenteeism among smokers obtained from earlier research, costs due to smoker absenteeism were estimated. Financial losses caused by passive smoking, smoking breaks, and occupational injuries were calculated.

RESULTS

Using a conservative estimate of excess absenteeism from work, male smokers took off an average of 4.36 sick days and male non-smokers took off an average of 3.30 sick days. Female smokers took off an average of 4.96 sick days and non-smoking females took off an average of 3.75 sick days. Excess absenteeism caused by employee smoking was estimated to cost USD 178 million per annum for males and USD 6 million for females at a total cost of USD 184 million per annum. The time men and women spent taking smoking breaks amounted to nine days per year and six days per year, respectively, resulting in reduced output productivity losses of USD 733 million. Increased sick leave costs due to passive smoking were approximately USD 81 million. Potential costs incurred from occupational injuries among smoking employees were estimated to be USD 34 million.

CONCLUSIONS

Financial costs caused by increased absenteeism and reduced productivity from employees who smoke are significant in Taiwan. Based on conservative estimates, total costs attributed to smoking in the workforce were approximately USD 1032 million.

Infection with a periodontal pathogen induces procoagulant effects in human aortic endothelial cells

BACKGROUND

Multiple studies have demonstrated a link between periodontal infections and vascular disease. Porphyromonas gingivalis, a major periodontal pathogen, has been shown to adhere to and invade endothelial cells.

OBJECTIVE

In order to dissect mechanisms underlying these observations, we assessed the role of P. gingivalis infection in modulating properties of endothelial cells linked to atherothrombosis.

METHODS

Primary human aortic endothelial cells (HAEC) were infected with either P. gingivalis 381 or its non-invasive fimbriae-deficient mutant, DPG3. Markers of coagulation and thrombosis were assessed 8 h and 18 h postinfection in cell lysates and supernatants.

RESULTS

Infection with P. gingivalis 381 significantly enhanced tissue factor expression and activity, and suppressed levels of tissue factor pathway inhibitor. Furthermore, P. gingivalis infection decreased levels and activity of tissue plasminogen activator, and enhanced plasminogen activator inhibitor-1 antigen and activity. Consistent with an important role for bacterial adhesion/invasion in this setting, infection with DPG3 failed to induce procoagulant properties in HAEC. Most of the above effects of P. gingivalis 381 were more apparent at the later time point (18 h postinfection). This suggests that P. gingivalis infection, rather than having an immediate and direct effect, might activate pathways that, in turn, trigger endothelial procoagulant mechanisms.

CONCLUSIONS

Taken together these data demonstrate for the first time that infection with a periodontal pathogen induces procoagulant responses in HAEC.

Properties of cAMP-dependent and Ca(2+)-dependent whole cell Cl- conductances in rat epididymal cells

Single rat epididymal cell studied under whole cell patch-clamp condition responded to 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (CPT-cAMP) (500 microM) and to ionomycin (1 microM) by an increase in whole cell conductance. A major part of the stimulated current was carried by Cl-, although a small part was due to nonselective cation current. After elimination of the cation current component by using impermeant cation, the cells revealed different Cl- conductance properties in response to adenosine 3',5'-cyclic monophosphate (cAMP) and ionomycin. The cAMP-stimulated Cl- conductance was independent of time and voltage and showed a linear current-voltage relationship. The anion permselectivity was NO3- > Br- > Cl- approximately I- >> SO(4)2-. The ionomycin-stimulated Cl- conductance showed marked time and voltage dependency. In contrast to the cAMP-induced anion permselectivity, the ionomycin-induced anion permselectivity was I- > Br- approximately NO3- > Cl- >> SO(4)2-. These results indicate that the epididymal epithelial cells exhibit different Cl- conductances sensitive to cAMP and Ca2+. The cAMP-activated conductance has properties resembling the type associated with the cystic fibrosis transmembrane conductance regulator found in cystic fibrosis-affected epithelia. This finding supports the notion that the epididymis is a cystic fibrosis epithelium.

Pro-inflammatory cytokine-stimulated first trimester decidual cells enhance macrophage-induced apoptosis of extravillous trophoblasts

OBJECTIVE

As human blastocyst-derived extravillous trophoblasts (EVTs) invade the early decidua, they are positioned to interact with immune cells and resident decidual cells, and remodel spiral arteries into high capacity vessels that increase blood flow to the developing fetal-placental unit. Shallow EVT invasion elicits incomplete vascular transformation and reduces uteroplacental blood flow that presages adverse pregnancy outcomes. Excess macrophages in the decidua induce EVT apoptosis via tumor necrosis factor-alpha (TNF-α) secretion. Our previous observation that pro-inflammatory cytokines enhance neutrophil and macrophage activator granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in first trimester decidual cells is now extended to include: (1) the specific macrophage activator M-CSF; (2) macrophage activation and subsequent enhancement of EVT apoptosis by both GM-CSF and M-CSF.

STUDY DESIGN

Quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay assessed M-CSF expression in first trimester decidual cells incubated with interleukin-1 beta (IL-1β) or TNF-α. Peripheral monocyte-derived macrophages pre-incubated with conditioned media from decidual cell cultures were co-cultured with a first trimester EVT cell line, HTR-8/SVneo cells. Macrophage activation was examined and EVT apoptosis evaluated by DNA fragmentation, caspase activation and cell membrane asymmetry.

RESULTS

IL-1β or TNF-α significantly enhanced M-CSF expression in first trimester decidual cells. The conditioned media from these cultures activates macrophages, which promote caspase 3/7-dependent EVT apoptosis with antibodies against GM-CSF or M-CSF blocking this effect.

CONCLUSIONS

Pro-inflammatory cytokines increases synthesis of M-CSF in first trimester decidual cells. Both GM-CSF and M-CSF activate macrophages, which initiate caspase-dependent EVT apoptosis.

Effect of angiotensins on electrogenic anion transport in monolayer cultures of rat epididymis

Confluent monolayers cultured from the rat cauda epididymidis have been shown to respond to angiotensin I (AI) and angiotensin II (AII) when studied under short-circuit conditions and bathed on both sides with Krebs-Henseleit solution. Both the decapeptide AI and the octapeptide AII elicited transient increases in short-circuit current (SCC) when added to the basolateral as well as to the apical surfaces, with the effect of basolateral application greater than that of apical application. The maximal responses produced by AI and AII were similar with median effective concentrations of 20 to 80 nmol/l. The increase in SCC by AII was dependent upon extracellular Cl- and was inhibited by addition of a Cl- channel blocker, diphenylamine 2-carboxylate, to the apical surface. These patterns of activity suggest that the SCC responses to angiotensins result from electrogenic chloride secretion. Pretreating the monolayers with captopril (100 nmol/l), an angiotensin-converting enzyme (ACE) inhibitor, reduced the response to basolateral application of AI, but completely abolished the response to AI added apically. These results suggest that the response to apical addition of AI was due to conversion of AI to AII which interacts with apical angiotensin receptors. This conversion was mediated by ACE which has been detected in epididymal monolayers. Of the endogenous ACE activity, 86% was found to be inhibited by captopril (100 nmol/l). Responses of the epididymal monolayers to angiotensins were mediated by specific angiotensin receptors. [Sar1,Ile8]-AII, a specific antagonist of the AII receptor, completely inhibited the responses to AI and AII but had no effect on the responses to bradykinin and endothelin.(ABSTRACT TRUNCATED AT 250 WORDS)

Decidual hemostasis, inflammation, and angiogenesis in pre-eclampsia

Invasion of the decidua by extravillous trophoblasts (EVTs) is accompanied by thrombin generation from decidual cell (DC)-expressed tissue factor (TF). This TF protects against hemorrhage as EVTs breach capillaries and subsequently invade and remodel spiral arteries and arterioles. Pre-eclampsia (P-EC) is the world's leading cause of fetal and maternal morbidity and mortality. It is associated with decidual hemorrhage and maternal thrombophilias, which form excess thrombin from DCs, and with maternal infections and other inflammatory conditions that are associated with excess expression of the proinflammatory cytokines interleukin (IL)-1 β and tumor necrosis factor (TNF) α. In human first-trimester leukocyte-free DCs, (1) thrombin enhances expression of soluble fms-like tyrosine kinase-1 (sFlt-1), a potent inhibitor of angiogenesis; (2) thrombin, IL-1β and TNF-α increase monocyte-recruiting chemokine expression leading to a macrophage excess in the pre-eclamptic decidua. The pathogenesis of P-EC likely stems from shallow EVT invasion leading to impaired decidual vascular remodeling. The resulting reduced uteroplacental blood flow is associated with a hypoxic placenta, which appears to secrete excess sFlt-1 into the maternal plasma. A regulatory role for DCs in vascular remodeling is indicated because impaired decidual vascular remodeling could stem from an aberrant local antiangiogenic milieu elicited by excess sFlt-1 and/or macrophage-inhibited EVT decidual invasion.

Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption

Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Among the cell types at the maternal fetal interface at term, TF expression is highest in decidual cells indicating that this TF meets the hemostatic demands of labor and delivery. TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggesting that the maintenance of elevated circulating progesterone provides hemostatic protection and that abruption-generated thrombin acts in an autocrine/paracrine fashion on decidual cells to promote hemostasis via enhanced TF expression.

Copolymers of itaconic anhydride and methacrylate-terminated poly(lactic acid) macromonomers

In an effort to design cyclic anhydride copolymers that have biodegradable characteristics and are derived from renewable resources, the copolymerization of itaconic anhydride and methacrylate-terminated poly-(L-lactic acid) (PLLA) was studied. Polymers with anhydride concentrations from 85 to 15 mol% have been synthesized successfully with retention of the cyclic anhydride. Molecular weights range from 9000 to 70,000 with higher molecular weights for higher concentrations of PLLA macromonomer. High conversions are observed for samples containing 50% and less itaconic anhydride with a slight tendency for the polymer to be enriched in the monomer in smaller concentration. These copolymers show glass transition temperatures between 31 and 73 degrees C, increasing with increased itaconic anhydride content. No evidence of crystallinity from the PLLA is observed for these copolymers.

The differential effects of poly(2-hydroxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate)/poly(caprolactone) polymers on cell proliferation and collagen synthesis by human lung fibroblasts

Because of its chemical versatility and demonstrated biocompatibility, poly(2-hydroxyethyl methacrylate) (pHEMA) has been widely used as a polymer for biomedical applications. Since this hydrophilic material shows a poor interface with cells, blendings with other polymers were done to improve cytocompatibility. In our polymer, the presence of hydrophobic dominions on the material surface, due to the interpenetrating polymerization of pHEMA with poly(caprolactone) (PCL), seems to ameliorate the cytocompatibility in terms of cell adhesion and metabolism. For our experiments, we used IMR-90 human fibroblasts, as these cells strongly regulate DNA, RNA, and protein synthesis as anchorage-dependent variables. Cell attachment on a pHEMA/PCL interpenetrating polymer network was optimal, suggesting a strong adhesion between the cells and the polymer surface. Cell adhesion was weaker on pHEMA, as a significant fraction of the fibroblasts revealed a lack of spreading, with most cells remaining spherical. Moreover, only fibroblasts seeded on pHEMA significantly decreased mRNA synthesis; collagen production and cell shapes ranged from fully flat and proliferating, to minimally spread and nonproliferating. Finally, DNA synthesis, as a measure of cell proliferation, was markedly inhibited in cells cultured on pHEMA but not on pHEMA/PCL. In conclusion, our results suggest that control of cell growth and metabolism by biomedical polymers is based on physicochemical mechanism(s) in which the hydrophilicity/hydrophobicity ratio of the material surfaces may play an important role.

Changes in hemodynamics of the carotid and middle cerebral arteries before and after endoscopic sympathectomy in patients with palmar hyperhidrosis: preliminary results

OBJECT

The purpose of this study was to analyze the change in carotid and middle cerebral artery (MCA) hemodynamics before and after endoscopic upper thoracic sympathectomy in patients with palmar hyperhidrosis (PH).

METHODS

Sixty-eight patients with PH (35 males and 33 females) for whom the average age was 24.5+/-10.7 years (+/- standard deviation) were recruited into this study. These patients all underwent routine upper T-2 sympathectomy to treat their PH. Ultrasonography studies of the carotid arteries (CAs) and MCA were obtained in each patient before and after T-2 sympathectomy. The blood flow volume, flow velocity, and resistivity index (RI) in the bilateral common CAs (CCAs), internal CAs (ICAs), and external CAs (ECAs) were evaluated using duplex ultrasonography. The systolic peak velocity, mean velocity, diastolic peak velocity, pulsatility index, and RI of the bilateral MCAs were evaluated using transcranial Doppler ultrasonography. Blood pressure and heart rate were also recorded during this study. The Student paired t-test was used to analyze the differences between studies before and after bilateral T-2 sympathectomy. There was a significant reduction in diastolic pressure after T-2 sympathectomy (p = 0.003), but not in systolic pressure or heart rate. The vessel diameter was increased after sympathectomy in the left CAs and right CCA. The T-2 sympathectomy led to significant elevation of blood flow volume and RI in the left CCA, ICA, and ECA (p < 0.05). The authors found significant increases in maximum flow velocity and RI in the left MCA (p < 0.05).

CONCLUSIONS

Patients who underwent T-2 sympathectomy demonstrated a significant increase in blood flow volume and flow velocities of the CAs and MCA, especially on the left side. Asymmetry of sympathetic influence on the hemodynamics of the CAs and MCA was noted. The usefulness of sympathectomy for the treatment of ischemic cardiovascular and cerebrovascular disease deserves further investigation.

The Correlation between Airborne Methicillin-resistant Staphylococcus aureus with the Presence of MRSA Colonized Patients in a General Intensive Care Unit

Air sampling directly onto a methicillin-resistant Staphylococcus aureus (MRSA) selective agar was performed at six locations three times weekly over a period of 32 weeks in a new, initially MRSA-free Intensive Care Unit to examine if MRSA is present in air sample cultures and, if so, whether it is affected by the number of MRSA colonized patients present. A total of 480 air samples were collected on 80 days. A total of 39/480 (8.1%) samples were found to be MRSA positive of which 24/160 (15%) positive air samples were from the single rooms, where MRSA colonised patients were isolated, and 15/320 (4.7%) were from the open bed areas. A significant correlation was found between the daily number of MRSA colonized or infected patients in the Unit and the daily number of MRSA positive air samples cultures obtained (r2=0.128; P<0.005). The frequency of positive cultures was significantly higher in the single rooms than in the open bed areas (relative risk=3.2; P<0.001). The results from one of the single rooms showed a strong correlation between the presence of MRSA patients and MRSA positive air samples (relative risk=11.4; P<0.005). Our findings demonstrate that the presence of airborne MRSA in our unit is strongly related to the presence and number of MRSA colonized or infected patients in the Unit.