Sexual growth and destiny beliefs: Longitudinal associations with dyadic coping among couples seeking medically assisted reproduction

BACKGROUND

Medically assisted reproduction is a vulnerable time for couples' sexual health. Believing that sexual challenges can be worked through (i.e., sexual growth beliefs) or that these challenges indicate incompatibility (i.e., sexual destiny beliefs) may be related to dyadic coping-the strategies couples use to cope-with the physical and psychological stressors of medically assisted reproduction.

AIM

In the current study we aimed to examine the longitudinal associations between typical (i.e., average) levels of sexual growth and destiny beliefs and positive and negative facets of dyadic coping and how greater than typical levels of these constructs predicted each other across time.

METHODS

Couples (n = 219) seeking medically assisted reproduction were recruited for an online longitudinal, dyadic study.

OUTCOMES

Couples completed online measures of sexual growth and destiny beliefs and positive and negative dyadic coping at baseline, 6-and 12-months.

RESULTS

Random intercept cross-lagged panel models demonstrated that at the within-person level, reporting higher sexual growth beliefs at baseline, relative to their average across time points, was associated with lower negative dyadic coping at 6 months. Higher negative dyadic coping at 6 months, relative to their average, was linked to lower sexual growth beliefs at 12-months. When individuals reported higher sexual destiny beliefs at 6-months, relative to their average, they and their partners reported higher negative dyadic coping at 12 -months. At the between-person level, higher overall levels of sexual destiny beliefs were related to higher overall levels of negative dyadic coping. No associations with positive dyadic coping were identified.

CLINICAL IMPLICATIONS

Couples may benefit from identifying and reducing unhelpful beliefs about sex and negative dyadic coping.

STRENGTHS AND LIMITATIONS

Strengths of this study include our large, inclusive sample, engagement of community partners, and novel analytical approach to assess change over time. However, following couples in 6-month increments and not using questionnaires specific to medically assisted reproduction may have limited our ability to detect nuanced changes that couples experience during this time.

CONCLUSION

Lower sexual growth and higher sexual destiny beliefs may promote couples' engagement in less adaptive coping behaviors as they seek medically assisted reproduction.

Perceived financial burden is indirectly linked to sexual well-being via quality of life among couples seeking medically assisted reproduction

Introduction

Medically assisted reproduction is a difficult treatment process for couples both financially and sexually. Yet, these two domains have not been examined together among couples seeking treatment, leaving couples and practitioners without guidance on how to address these domains together.

Methods

In line with Couples and Finance Theory, we tested the hypothesis that perceived financial burden and couple income would predict quality of life during medically assisted reproduction, which would then predict four domains of sexual well-being (i.e., sexual satisfaction, desire, distress, and frequency). We also examined if the results differed by treatment status—that is, between partners who were receiving treatment and those who were not. Cross-sectional data from 120 couples who had undergone medically assisted reproduction in the past six months were analyzed via structural equation modeling through an actor-partner interdependence mediation model.

Results

An individual’s greater perceived financial burden predicted their own lower quality of life during medically assisted reproduction, which in turn predicted their lower sexual satisfaction, desire and distress, as well as their partner’s lower sexual satisfaction. Household income did not indirectly predict any sexual well-being domains, and results regarding treatment status were inconclusive.

Discussion

Clinicians can discuss with couples how perceived financial strain of medically assisted reproduction affects their quality of life and what ramifications that may have for their sexual well-being.

A Longitudinal Investigation of Couples' Sexual Growth and Destiny Beliefs in the Transition to Parenthood

Beliefs about sexuality tend to become more salient during sexual challenges and are associated with how individuals respond to these difficulties and, in turn, their sexual well-being. The transition to parenthood is marked by significant changes to couples' sexuality. As such, this period of vulnerability may be an important context in which these beliefs impact how couples manage sexual stressors and may have implications for their sexual well-being. In a longitudinal dyadic study, we examined whether couples' sexual growth beliefs (e.g., beliefs that sexual problems can be resolved through effort) and sexual destiny beliefs (e.g., beliefs that sexual problems reflect incompatibility with their partner) correspond with changes to various facets of couples' sexual well-being over time. First-time parent couples (N = 203) completed online surveys assessing these beliefs in pregnancy (32 weeks) and measures of sexual well-being (satisfaction, desire, and distress) in pregnancy (20 and 32 weeks) and across the postpartum period (3, 6, 9, 12 months). Dyadic latent growth curve models showed that expectant mothers who reported stronger sexual destiny beliefs in pregnancy reported higher sexual distress and lower sexual satisfaction at 3 months postpartum. When partners reported stronger sexual destiny beliefs in pregnancy, both they and new mothers reported greater sexual desire at 3 months postpartum. Unexpectedly, partners' higher sexual growth beliefs in pregnancy predicted mothers' lower sexual desire at 3 months postpartum. Sexual growth and destiny beliefs were not associated with change in couples' sexual well-being beyond 3 months postpartum. Findings shed light on the potential benefits and costs of sexual growth and destiny beliefs for couples' sexual well-being early in the postpartum period, but not over time.

Comparing Self-Reported Pain During Intercourse and Pain During a Standardized Gynecological Exam at 12- and 24-Month Postpartum

BACKGROUND

There is limited information about the physical indicators and biopsychosocial predictors of self-reported pain during intercourse and pain during a gynecological examination at 12- and 24-month following childbirth.

AIM

This longitudinal study aimed to (i) Compare the findings from gynecological exams at 12- and 24-month postpartum for women with minimal vs clinically significant pain during intercourse; (ii) Assess the biomedical and psychosocial correlates of self-reported pain during intercourse and the vestibular pain index (VPI) from the cotton-swab test at 12- and 24-month postpartum; (iii) Establish the relationship between self-reported pain during intercourse and the cotton-swab test.

METHODS

Women (N = 97 at 12 months postpartum and N = 44 at 24-month postpartum) recruited from a local women's hospital completed online surveys in their first trimester of pregnancy and at 12- and 24-month postpartum to assess pain during intercourse and biopsychosocial variables. Those with clinically significant (pain ≥4/10 on a visual analogue scale) were matched with those reporting minimal pain (pain <3/10) and underwent a gynecological exam including a cotton-swab test. Descriptive analyses, multiple regressions, and bivariate correlations were conducted to address each of the study aims, respectively.

MAIN OUTCOME MEASURES

(i) Findings from the gynecological examination (ii) Numerical rating scale for the VPI; (iii) Visual analogue scale of pain during intercourse.

RESULTS

The majority of women in both pain groups had normal physical findings in the gynecological exam. Greater sexual distress and pain catastrophizing at 12- and 24-month postpartum were significantly associated with greater pain during intercourse at each time-point, respectively. Greater pain catastrophizing at 12 months postpartum was significantly associated with greater pain during the cotton-swab test at that time-point. Lower relationship satisfaction at 12 months postpartum was associated with greater VPI ratings at 24 months postpartum. Pain during intercourse and the VPI were moderately and positively correlated.

CLINICAL IMPLICATIONS

Addressing psychosocial variables may interrupt the maintenance of postpartum pain. Following an initial assessment, self-reported pain intensity may be a suitable proxy for repeated examinations.

STRENGTHS & LIMITATIONS

This study is the first to describe the physical findings and psychosocial predictors of pain during intercourse and the VPI at 12- and 24-month postpartum. The homogenous and small sample may limit generalizability.

CONCLUSION

There were no observable physical indicators of clinically significant postpartum pain during intercourse. Psychosocial variables were linked to women's greater postpartum pain during intercourse and VPI ratings.

Tranquility: An adaptation co-design and fidelity evaluation of an internet-based cognitive-behavioural therapy (iCBT) program for anxiety and depression

Background

Internet-based cognitive behavioral therapy (iCBT) is a necessary step toward increasing the accessibility of mental health services. Yet, few iCBT programs have been evaluated for their fidelity to the therapeutic principles of cognitive behavioral therapy (CBT) or usability standards. In addition, many existing iCBT programs do not include treatments targeting both anxiety and depression, which are commonly co-occurring conditions.

Objective

This study aims to evaluate the usability of Tranquility—a novel iCBT program for anxiety—and its fidelity to CBT principles. This study also aims to engage in a co-design process to adapt Tranquility to include treatment elements for depression.

Methods

CBT experts (n=6) and mental health–informed peers (n=6) reviewed the iCBT program Tranquility. CBT experts assessed Tranquility’s fidelity to CBT principles and were asked to identify necessary interventions for depression by using 2 simulated client case examples. Mental health–informed peers engaged in 2 co-design focus groups to discuss adaptations to the existing anxiety program and the integration of interventions for depression. Both groups completed web-based surveys assessing the usability of Tranquility and the likelihood that they would recommend the program.

Results

The CBT experts’ mean rating of Tranquility’s fidelity to CBT principles was 91%, indicating a high fidelity to CBT. Further, 5 out of 6 CBT experts and all mental health–informed peers (all participants: 11/12, 88%) rated Tranquility as satisfactory, indicating that they may recommend Tranquility to others, and they rated its usability highly (mean 76.56, SD 14.07). Mental health–informed peers provided suggestions on how to leverage engagement with Tranquility (eg, adding incentives and notification control).

Conclusions

This preliminary study demonstrated the strong fidelity of Tranquility to CBT and usability standards. The results highlight the importance of involving stakeholders in the co-design process and future opportunities to increase engagement.

Sexual Function and Satisfaction in Couples with Infertility: A Closer Look at the Role of Personal and Relational Characteristics

BACKGROUND

Research to date suggests that couples undergoing assisted reproductive technology (ART) are at a high risk of experiencing sexual difficulties.

AIM

This dyadic cross-sectional study aimed to provide a better understanding of the infertility-specific personal (ie, emotional, mind-body) and relational stressors associated with the sexual desire, orgasm, arousal, and sexual satisfaction of infertile couples seeking ART.

METHODS

The sample included 185 mixed-sex infertile couples seeking ART. Participants completed online the Fertility Quality of Life tool and either the Female Sexual Function Index or the International Index of Erectile Function. Data were analyzed using path analyses based on the Actor-Partner Interdependence Model.

OUTCOMES

Individuals' own and their partners' sexual function (desire, orgasm, arousal domains) and sexual satisfaction.

RESULTS

For men and women, infertility-related emotional stressors were associated with their own and their partner's lower sexual desire. For women, experiencing greater infertility-related emotional stressors was also associated with their partner's lower sexual satisfaction. While experiencing greater infertility-related mind-body stressors was not associated with men and women's own sexual desire, arousal, orgasm, and satisfaction, for women, it was associated with their partner's lower sexual arousal. Lastly, for men and women, infertility-related relational stressors were associated with their own lower sexual arousal, as well as with their own and their partner's lower sexual satisfaction. For women, experiencing greater relational stressors was also associated with their own lower sexual desire and orgasm.

CLINICAL IMPLICATIONS

Interventions addressing the emotional, mind-body, and relational spheres of infertile couples seeking ART may help facilitate improvements in sexual function and satisfaction and better serve their needs.

STRENGTHS & LIMITATIONS

This study included a large sample of couples. Our sample was heterogeneous with regards to couples' cause of infertility and treatment stage. The use of an infertility-related measure allowed us to better capture personal and relational stressors specific to couples seeking ART. Given the cross-sectional design of our study, causality between infertility-related stressors and sexual function and satisfaction cannot be inferred. Our sample included predominantly White, mixed-sex individuals with a high level of education, which may reduce the generalizability of our findings.

CONCLUSION

Couples' subjective experience of infertility and treatment (personal and relational stressors) seems to be strongly associated with their sexual health, allowing us to identify potential targets of intervention with couples seeking ART. S.E. Amiri, A Brassard, N.O. Rosen, et al. Sexual Function and Satisfaction in Couples with Infertility: A Closer Look at the Role of Personal and Relational Characteristics. J Sex Med 2021;18:1984-1997.

Biased Partner Perceptions of Women's Pain Self-Efficacy in Postpartum Pain During Intercourse: A Dyadic Longitudinal Examination

Postpartum pain during intercourse is a prevalent and distressing problem that has substantial consequences for affected couples. Partner perceptions-such as how partners perceive women's pain self-efficacy-contribute to an individual's pain experience. This study examined whether partners under- or over-estimate women's intercourse pain self-efficacy at 3-months postpartum and the implications of this bias for women's pain and couples' sexual functioning at 3- and 6-months postpartum. Women who reported pain during intercourse and their partners (N = 89 couples) completed online measures assessing pain self-efficacy (own or partner perceptions), pain intensity, and sexual functioning at 3- and 6-months postpartum. Analyses were based on the Truth and Bias Model of Judgement and Response Surface Analysis. Partners were accurate in their estimates of women's pain self-efficacy (ie, their estimates were positively correlated with women's), but they also underestimated it by perceiving women to be less efficacious than women themselves reported. When couples showed greater agreement for lower levels of pain self-efficacy at 3 months, women reported greater pain intensity and both partners reported poorer sexual functioning at 3- and 6-months postpartum. Findings may inform interventions that promote pain self-efficacy to improve partner support and couples' sexual functioning. PERSPECTIVE: When women report-and their partners perceive-low levels of women's self-efficacy for managing painful intercourse, women report greater postpartum pain during intercourse and couples indicate poorer sexual functioning. These findings suggest that interventions aimed at promoting couples' agreement at high pain self-efficacy may improve their adjustment to postpartum pain.

A Descriptive and Longitudinal Analysis of Pain During Intercourse in Pregnancy

INTRODUCTION

Pain during vaginal intercourse in pregnancy has largely been ignored despite physiological and psychological components of pregnancy that may be associated with its onset and persistence.

AIM

The current study aimed to determine the prevalence and the characteristics of clinically significant pain during intercourse in the second (18-24 weeks) and third (32-36 weeks) trimesters of pregnancy.

METHODS

Pregnant women (N = 501) recruited from a local women's hospital completed an online survey in the second and third trimesters of their pregnancy regarding the presence, intensity, and characteristics of pain during intercourse. Women with clinically significant pain (ie, pain greater than or equal to 4 of 10 on a numerical rating scale) were grouped according to whether the pain was resolved, persistent, or new onset across the 2 pregnancy time points. Following guidelines outlined by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT), we conducted a descriptive analysis assessing the intensity and characteristics (eg, quality, onset, degree of improvement over time, and treatment strategies utilized) of clinically significant pain during intercourse.

MAIN OUTCOME MEASURE

The main outcome measures in this study were the prevalence, intensity, and characteristics of clinically significant pain during intercourse.

RESULTS

Overall, 21% of pregnant women (106/501) reported clinically significant pain during intercourse. We found that 22% (N = 16/106) of women who had this pain at 20 weeks reported that it had resolved at 34 weeks, 33% (40/106) reported persistent pain at both time points, and 46% (50/106) reported new onset of pain during intercourse at 34 weeks. The majority of women across all pain groups reported that the pain began during pregnancy and remained at the same intensity. Most women reported not using any pain management strategies to cope with their pain.

CLINICAL IMPLICATIONS

One in 5 women experienced clinically significant pain during intercourse in pregnancy, with the majority of women not seeking treatment.

STRENGTHS & LIMITATIONS

This study is the first to comprehensively assess and describe the prevalence and characteristics of clinically significant pain during intercourse across 2 time points in pregnancy using IMMPACT guidelines. Small sample sizes in our pain groups may limit the generalizability of pain characteristics.

CONCLUSION

Findings suggest that many pregnant women in this study experienced significant pain during intercourse in pregnancy. Understanding the characteristics of this pain may improve its identification by health care providers and inform better prevention and treatment recommendations. Rossi MA, Mooney KM, Binik YM, et al. A Descriptive and Longitudinal Analysis of Pain During Intercourse in Pregnancy. J Sex Med 2019;16:1966-1977.

Analysis of Glutathione-Dependent Enzyme Activities in two Different Rat Hepatomas and in Normal Liver in Relation to their Role in Resistance to Oxidative Stress

The importance of some glutathione metabolic pathways was examined in two highly dedifferentiated hepatomas, Yoshida AH-130 and Morris 3924 A hepatomas, and in normal liver in relation to their role against oxidative stress. The cytosol prepared from Yoshida hepatoma cells decreased the peroxidation rate in normal liver microsomes and mitochondria, but this antioxidant property was not displayed by Morris hepatoma. Glutathione peroxidase and glutathione-S-transferases activities were extremely low in both hepatomas; glutathione reductase activity values were about half the normal liver values. The large decrease in glutathione peroxidase and glutathione-S-transferases suggests that in these two tumors only small amounts of GSH can be used in reduction or conjugation reactions, such as the reduction of hydrogen peroxide and lipid hydroperoxides or the conjugation of GSH with the end products of lipoperoxidation, aldehydes or ketones. The hypothesis of a more efficient GSSG reduction in hepatomas, due to the low glutathione peroxidase/glutathione reductase activity ratio, is also discussed. The described changes in glutathione related enzymes do not seem to have any correlation with the protective effect against the lipoperoxidative processes displayed by some tumors since these enzymatic activities were similar in both hepatomas whereas only Yoshida hepatoma showed antioxidant properties.

Vulvodynia: a consideration of clinical and methodological research challenges and recommended solutions

Vulvodynia, an idiopathic chronic vulvar pain, is a prevalent genital pain condition that results in significant impairment to sexual, relational, and psychological functioning of affected women and their romantic partners. Despite its high prevalence, there remain gaps in knowledge and health care access for women coping with vulvodynia, given its varied clinical presentation and no widely accepted treatment protocol. The past several decades have seen important advancements in understanding vulvodynia and developing effective treatments; however, progress has been impeded due to clinical and methodological challenges in conducting research with this vulnerable population. This review presents a brief overview of vulvodynia correlates, consequences, etiology, and treatment, and then turns its attention to considering the clinical and methodological challenges that hinder vulvodynia research. Identifying these barriers alongside potential mitigating solutions is essential to developing empirically supported treatments for all women affected by vulvodynia, across all age and minority groups. Potential solutions will require researchers to broaden eligibility criteria, examine subgroups of women, and expand definitions of treatment outcomes, and may be best facilitated by more active collaboration among research groups and across relevant disciplines. Engagement in these solutions may contribute to more representative findings and the development and dissemination of empirically based treatment options for this complex pain condition.

The left lung is preferentially targeted during experimental paracoccidioidomycosis in C57BL/6 mice

Paracoccidioidomycosis (PCM) is a chronic systemic mycosis caused by the inhalation of the thermally dimorphic fungus Paracoccidioides brasiliensis as well as the recently described P. lutzii. Because the primary infection occurs in the lungs, we investigated the differential involvement of the right and left lungs in experimental P. brasiliensis infection. Lungs were collected from C57BL/6 mice at 70 days after intravenous infection with 1×10⁶ yeast cells of a virulent strain of P. brasiliensis (Pb18). The left lung, which in mice is smaller and has fewer lobes than the right lung, yielded increased fungal recovery associated with a predominant interleukin-4 response and diminished synthesis of interferon-γ and nitric oxide compared with the right lung. Our data indicate differential involvement of the right and left lungs during experimental PCM. This knowledge emphasizes the need for an accurate, standardized protocol for tissue collection during studies of experimental P. brasiliensis infection, since experiments using the same lungs favor the collection of comparable data among different mice.

Survey of the levels of antimicrobial resistance in Argentina: WHONET program--1991 to 1994

The World Health Organization has implemented an international program of antibiotic resistance survey, called WHONET, with the participation of 121 laboratories from 41 countries around the world. Argentina joined WHONET program in 1989. Five hospitals from Buenos Aires are taking part, under the coordination of the National Institute of Microbiology 'Dr. C. Malbran'. From the results obtained between 1991 and 1994, the low level of susceptibility to aminopenicillins, cephalosporins and aminoglycosides is remarkable. On the other hand, vancomycin-resistant Enterococcus spp. and Staphylococcus spp. have not been detected and imipenem resistance in Pseudomonas aeruginosa, and Acinetobacter spp. isolates has not overcome 7% and 11%, respectively. Analytical programs utilizing these data aid in the understanding of the epidemiology of antibiotic resistance and in the development of rational antibiotic prescription practices and infection control procedures.

Evidence of the presence of T helper type 17 cells in chronic lesions of human periodontal disease

INTRODUCTION

Periodontal disease is a chronic inflammation of the attachment structures of the teeth, triggered by potentially hazardous microorganisms and the consequent immune-inflammatory responses. In humans, the T helper type 17 (Th17) lineage, characterized by interleukin-17 (IL-17) production, develops under transforming growth factor-beta (TGF-beta), IL-1beta, and IL-6 signaling, while its pool is maintained by IL-23. Although this subset of cells has been implicated in various autoimmune, inflammatory, and bone-destructive conditions, the exact role of T lymphocytes in chronic periodontitis is still controversial. Therefore, in this study we investigated the presence of Th17 cells in human periodontal disease.

METHODS

Gingival and alveolar bone samples from healthy patients and patients with chronic periodontitis were collected and used for the subsequent assays. The messenger RNA expression for the cytokines IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 in gingiva or IL-17 and receptor activator for nuclear factor-kappaB ligand in alveolar bone was evaluated by real-time polymerase chain reaction. The production of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 proteins was evaluated by immunohistochemistry and the presence of Th17 cells in the inflamed gingiva was confirmed by immunofluorescence confocal microscopy for CD4 and IL-17 colocalization.

RESULTS

Our data demonstrated elevated levels of IL-17, TGF-beta, IL-1beta, IL-6, and IL-23 messenger RNA and protein in diseased tissues as well as the presence of Th17 cells in gingiva from patients with periodontitis. Moreover, IL-17 and the bone resorption factor RANKL were abundantly expressed in the alveolar bone of diseased patients, in contrast to low detection in controls.

CONCLUSION

These results provided strong evidence for the presence of Th17 cells in the sites of chronic inflammation in human periodontal disease.

B cells are involved in the modulation of pathogenic gut immune response in food-allergic enteropathy

Food enteropathies involve uncontrolled or hypersensitivity reactions to ingested nutrients and may result in IgE and T-helper type 2 (Th2) responses as in food allergy. However, the precise role of B cells in the development of food enteropathies remains uncertain. In this work, we used B cell-deficient mice (B KO) and a model of peanut sensitization to examine the involvement of B lymphocytes in the pathogenesis of food allergy. Results showed that priming of wild-type (WT) mice with peanut proteins induced specific IgG1 and IgE responses in serum, with edema, tissue destruction, epithelial exulceration and inflammatory infiltrate in the gut of sensitized and challenged (S + Peanut) WT animals. In contrast, there was no sera immunoglobulin detection and absence of tissue destruction in the gut of B KO mice, which presented moderate inflammatory infiltrate and villous enlargement after peanut challenge. These animals presented marked decrease in IL-4 and TNF-alpha and high levels of IL-10, TGF-beta, IL-12p40 and IFN-gamma mRNA in the gut. Moreover, the expression of CCL5, CCL11 and CXCL1 was reduced in the gut of B KO mice, in contrast to elevated messages of CCL2 or similar detection of Th1-related chemokines in S + Peanut WT mice. Finally, we provided evidence that B cells are necessary to the development of food-related enteropathies and induction of gut inflammation during allergic reactions to food.

Modulation of mucosal immunity in a murine model of food-induced intestinal inflammation

BACKGROUND

Hypersensitivity or uncontrolled responses against dietary antigens can lead to inflammatory disorders like food allergy and current models reflect a variety of causes but do not reveal the detailed modulation of gut immunity in response to food antigens after breakdown in mucosal tolerance.

OBJECTIVE

To develop and characterize a murine model for food-induced intestinal inflammation and to demonstrate the modulation of gut immune response by dietary allergenic antigens.

METHODS

C57BL/6 mice were sensitized with peanut proteins, challenged with peanut seeds and their sera and gut segments were collected for subsequent analyses.

RESULTS

Sensitization and challenged with peanut seeds led to alterations in gut architecture with inflammatory response characterized by oedema in lamina propria and cell infiltrate composed mainly by eosinophils, mast cells, phagocytes, natural killer and plasma cells, together with low percentage of gammadelta+ and CD4+CD25+Foxp3+ cells in Peyer's patches. These animals also presented high levels of specific IgE and IgG1 in sera and modulation of mucosal immunity was mediated by increased expression of GATA-3, IL-4, IL-13 and TNF-alpha in contrast to low IFN-gamma in the gut.

CONCLUSION

A murine model for food-induced intestinal inflammation was characterized in which modulation of gut immunity occurs by peanut antigens in consequence of T-helper type 2 (Th2) allergic response and failure of regulatory mechanisms necessary for mucosa homeostasis, resembling food allergy. This work shed some light on the understanding of the pathogenesis of gastrointestinal disorders and intolerance in the gut and supports the development of therapies for food-related enteropathies like food allergy, focusing on gut-specific immune response.

Peroxynitrite mediates the failure of neutrophil migration in severe polymicrobial sepsis in mice

BACKGROUND AND PURPOSE

Sepsis is a systemic inflammatory response resulting from the inability of the host to restrict local infection. The failure of neutrophil migration to the infection site is one of the mechanisms involved in this process. Recently, it was demonstrated that this event is mediated by nitric oxide (NO). The present study addresses the possibility that peroxynitrite (ONOO(-)), a NO-derived powerful oxidizing and nitrating compound, could also be involved in neutrophil migration failure.

EXPERIMENTAL APPROACH

Male C57Bl/6 mice were subjected to moderate (MSI) or severe (SSI) septic injury, both induced by cecal ligation and puncture (CLP). The leukocyte rolling and adhesion in the mesentery was evaluated by intravital microscopy. Cytokines (TNF-alpha and MIP-1alpha) were measured by ELISA and 3-nitrotyrosine (3-NT) by immunofluorescence.

KEY RESULTS

Compared with saline pretreatment of SSI mice, pre-treatment with uric acid, a ONOO(-) scavenger, partially restored the failure of neutrophil rolling, adhesion and migration to the site of infection. These mice also presented low circulating bacterial counts and diminished systemic inflammatory response. Pretreatment with uric acid reduced 3-NT labelling in leukocytes in mesenteric tissues and in neutrophils obtained from peritoneal exudates. Finally, uric acid pretreatment enhanced significantly the survival rate in the SSI mice. Similarly, treatment with FeTPPs, a more specific ONOO(-) scavenger, re-established neutrophil migration and increased mice survival rate.

CONCLUSIONS AND IMPLICATIONS

These results indicate that ONOO(-) contributed to the reduction of neutrophil/endothelium interaction and the consequent failure of neutrophil migration into infection foci and hence susceptibility to severe sepsis.

Morphometric analysis of experimentally induced periapical lesions: radiographicvshistopathological findings

OBJECTIVES

To evaluate the accuracy and reliability of conventional (Kodak Ektaspeed Plus film) and digitized radiographic images to detect the presence as well to estimate the size, as measured by an image analysis programme, of periapical radiolucencies induced in dog teeth in comparison with the histomorphometric data obtained from the same lesions by conventional and fluorescence microscopy.

METHOD

After the removal of pulp, the root canals of five premolars from the same animal were left exposed for 7 days after which they were sealed for 60 days. At day 53, three more premolars were opened and left exposed to the oral cavity for 7 days. Intact premolars were used as control. Conventional radiographs were taken at day 0, day 7, day 30, day 45 and day 60. Morphometry in digitized radiographic images and histological sections were compared at day 7 and day 60 after setting the experimental series.

RESULTS

Radiographically, periapical lesions were only detected 30 days after coronal sealing. A progressively increasing radiolucent lesion area was observed at day 45 and day 60. Histopathologically, 7 days after pulp removal dense inflammatory infiltrate and root resorption in the periapical region was observed. At day 7 and day 60, the lesion sizes were similar when evaluated by both conventional and fluorescence microscopy. Lesion size was about 20% larger in digitized radiographs in comparison with histological measurements.

CONCLUSIONS

Although image digitization could not improve the detection of the early stages of periapical lesions, it provides a valuable quantitative assessment of extensive periapical lesions. In addition, fluorescence light microscopy enhances the visualization of the apical and periapical structures and seems to be a highly useful tool for histological evaluation, valuable for both qualitative and quantitative studies of periapical disease.

Mitochondrial damage as an early event of monensin-induced cell injury in cultured fibroblasts L929

The present study was designed to identify, submicroscopically, the primary organelle or target structure for monensin in cultured murine fibroblasts L929. In addition, the effect of the drug on cell size and surface membranes of the cells were analysed; cellular proliferation, collagen secretion, and necrosis and apoptosis were re-evaluated. At the lowest concentration of monensin the foremost ultrastructural alteration occurred in the mitochondria, characterized by increased matrix density with disorganized and less distinct crystae. Incubation with monensin at higher concentrations resulted in severe mitochondrial damage and marked dilatation of the Golgi apparatus and rough endoplasmic reticulum cisternae. Fibroblasts exposed to higher concentrations of monensin were enlarged with decreased number of filopodia and hollows in the surface membrane. Moreover, monensin inhibited the cell proliferation, increased immunohistochemical positiveness for collagen type I in a dose-dependent manner, and, at high concentrations, caused cell necrosis whereas apoptosis was not induced. Taken together, these results show that monensin induces early mitochondrial damage, possibly causing an energy deficit that led to inhibition of fibroblasts proliferation and accumulation of collagen causing dilatation of Golgi apparatus and rough endoplasmic reticulum. Moreover, the mitochondrial damage would also explain the monensin-induced necrosis.

Spatial memory in aged rats is related to PKCgamma-dependent G-protein coupling of the M1 receptor

In the present study, individual differences in spatial memory in aged Fischer 344 (F344) rats were associated with the extent of G-protein coupling of the M1 muscarinic receptor and the dendritic-to-somal ratio of hippocampal PKCgamma (d/sPKCgamma) immunogenicity. Following testing in the eight-arm radial maze task, 7 young and 13 aged rat brains were sectioned through the dorsal hippocampal formation (HF). G-protein coupling of the M1 receptor was assessed autoradiographically using competition binding studies in the presence and absence of a G-protein uncoupler to determine high (K(H)) and low (K(L)) affinity states for agonist in the HF, neocortex, and amygdala. In aged animals, a relationship between choice accuracy in the maze and K(H), a measure of M1 receptor-G-protein coupling was seen in the dentate gyrus, CA3, CA1, and neocortex. Furthermore, choice accuracy and d/sPKCgamma immunogenicity showed a significant relationship in CA1. Lastly, a correlation was seen in the CA1 of aged animals between K(H) and d/sPKCgamma. These relationships did not hold for the amygdala. Thus, individual differences in a naturally occurring age-dependent disruption of cholinergic-PKCgamma signal transduction is associated with spatial memory dysfunction.

Characterization of a bovine collagen–hydroxyapatite composite scaffold for bone tissue engineering

Different biomaterials have been used as scaffolds for bone tissue engineering. Here we characterize a biomaterial composed of sintered (1100 degrees C) and powdered hydroxyapatite (HA) and type I collagen (Coll), both of bovine origin, designed for osteoconductive and osteoinductive scaffolds. Coll/HA proportions were 1/2.6 and 1/1 (wet weight), and particles sizes varied from 200 to 400 microm. Vv (volume density) and Sv (surface to volume density) for the HA particles in the composite ranged from 0.48 +/- 0.06 to 0.55 +/- 0.02 and 5.090 +/- 0.545 to 6.366 +/- 0.289 microm(-1), respectively. Due to the relatively small changes in Vv and Sv, a macroporosity could be characterized for the biocomposite. X-ray diffraction and infrared spectroscopy showed that the sintered bone was composed essentially of HA with minimum additional groups such as surface calcium hydroxide, surface and crystal water, free carbon dioxide and possibly brushite. Mass spectrometry detected carbonates at A and B sites of HA, and weakly bound to the structure. Human osteoblasts adhered and spread on both the HA particle surface and the collagen fibers, which seemed to guide cells between adjacent particles. The biocomposite studied has several characteristics considered as ideal for its use as a scaffold for osteoconduction and osteoinduction.

Scanning electron microscopic study of the cleaning ability of chlorhexidine as a root-canal irrigant

AIM

To evaluate in vitro the cleaning of root-canal walls after irrigation with different irrigants.

METHODOLOGY

A total of 36 recently extracted human teeth were divided into four experimental groups according to the irrigating solution used: saline; 2% chlorhexidine; 2.5% sodium hypochlorite; and 2.5% sodium hypochlorite + EDTA. The cleaning of the apical, middle and coronal thirds of the root canals was evaluated by scanning electron microscope examination using a 4-point scoring system.

RESULTS

The best cleaning was obtained using 2.5% sodium hypochlorite and EDTA, followed by 2.5% sodium hypochlorite only (P < 0.05), whose cleaning was similar to chlorhexidine only in the cervical third. Cleaning by saline and 2% chlorhexidine was worse than the other two groups and was similar in all thirds. Better cleaning was found in the cervical and middle thirds for all groups with the worst results in the apical third.

CONCLUSIONS

The apical third of the root canals was not cleaned as well as the middle and coronal thirds. Cleaning by chlorhexidine and saline was inferior compared to the cleaning by sodium hypochlorite with and without EDTA.

Experimental studies on the mechanism of phospholipase C activation by the lipid peroxidation products 4-hydroxynonenal and 2-nonenal

The effects of three lipid peroxidation end-products, 4-hydroxynonenal (HNE), 2-nonenal (NE) and nonanal, on phosphoinositide-specific phospholipase C (PL-C) activity were studied in HL-60 cells. Enzymatic activity was determined by measuring the amounts of inositol-P3 (Ins-P3) produced by the cells incubated at 37 degrees C in the presence of the various compounds. HNE was shown to activate PL-C at concentrations of between 10(-8) and 10(-6) M; 10(-9) and 10(-8) M of NE also strongly stimulated PL-C. In contrast, nonanal failed to modify enzymatic activity. The concentrations of HNE and NE active on PL-C showed good correspondence with those that have been reported to be chemotactic towards rat neutrophils. The pretreatment of cells with 1 microM pertussis toxin completely prevented the increase of Ins-P3 production induced by HNE and NE. Maximal PL-C stimulation was produced by 10 nM NE; the degree of inositol-P3 production induced by the simultaneous addition of an equimolar dose of HNE was not significantly different from the activity value induced by NE alone, suggesting a possible competition between the two compounds. The data indicate that both HNE and NE share a common mechanism of action which, as with other better-known chemoattractants, involves PL-C activation through a G regulatory protein.

Chronic inhibition of NO synthesis per se promotes structural intimal remodeling of the rat aorta

OBJECTIVE

We characterized, using histomorphometry and transmission and scanning electron microscopy, the intimal remodeling of the thoracic aorta of normocholesterolemic young rats chronically-treated with N(omega)-nitro-L-arginine methylester (L-NAME) and examined the question whether these changes were caused by the lack of NO per se or by the hypertension which L-NAME administration induces.

METHODS

Male Wistar rats were divided randomly into three sets: control group, standard diet/L-NAME-treated group, and standard diet/L-NAME + captopril-treated group.

RESULTS

The treatment of rats with L-NAME for 4 weeks resulted in increased blood pressure (by 32% at the end of the treatment) as compared with the control value and intimal remodeling comprising a continuous layer of enlarged endothelial cells with irregular nuclear and cytoplasmic contours, lying over a thickened layer of fibrocollagenous support tissue focally expanded with lymphomononuclear cells and mainly diffuse foci of smooth muscle cells. In addition, the NO synthase inhibition caused a marked thickened tunica intima (150% thicker than the control value) and a significantly augmented intima : media ratio (126% higher than the control value). On the other hand, captopril prevented hypertension in rats simultaneously treated with L-NAME as compared with controls, and induced intimal remodeling comprising the same qualitative changes as those observed in L-NAME-treated rats. The tunica intima of l-NAME + captopril-treated rats was moderately thickened (60% increase in comparison with that of controls and 65% thinner as compared with L-NAME-treated rats). In the same way, the mean intima : media ratio of rats concomitantly treated with L-NAME and captopril was moderately increased (45% more) as compared with controls and significantly lower in comparison with rats administered L-NAME alone (36% less).

CONCLUSIONS

Chronic inhibition of NO synthesis per se promotes structural intimal remodeling of the rat aorta, which is potentiated by L-NAME-induced hypertension. Most important, the present findings favor the idea that blockade of NO synthesis by causing intimal remodeling might be a primary cause, as individual biologic phenomenon, in the development of an atherosclerotic plaque.

Further experiments on lipid peroxidation in transplanted and experimental hepatomas

The results of experiments on the subject of lipid peroxidation in hepatomas are described. It is now clear that lipid peroxidation is strongly decreased in most highly dedifferentiated hepatomas. It seems evident that the extent of the decline is strictly related to the degree of dedifferentiation. The model of diethylnitrosamine carcinogenesis, according to the method by Solt, Medline and Farber, has been now adopted to study the stages of carcinogenesis. It was shown that a net decline in lipid peroxidation occurs as early as at the stage of reversible nodules and progresses until the development of clear hepatomas. This change is practically simultaneous with a decline in the efficiency of the enzymes of the drug metabolizing system and in the content of cytochrome P450-Glutathione content and metabolism show also important changes. In fact, a dramatic increase in gamma-glutamyl-transpeptidase takes place very early during carcinogenesis, and is responsible for large decline in total glutathione during incubation of the homogenates. Glutathione peroxidase activity, on the contrary, is decreased, whereas glutathione reductase does not show significant changes. The supernatant of highly anaplastic tumors inhibits lipid peroxidation in normal liver homogenates, suggesting the presence of substances provided with antioxidant properties. These cannot be, however, related to a higher glutathione content. Supernatants from early nodules seem to be unable to block lipid peroxidation in normal liver homogenates. Preliminary experiments done to study the aldehyde pattern produced during lipid peroxidation, both in hepatomas and in nodules, confirm the presence of very poor lipid peroxidation and possibly of different peroxidation kinetics.

Connective tissue skeleton in the normal left ventricle and in hypertensive left ventricular hypertrophy and chronic chagasic myocarditis

Pictures certainly are worth a thousand words in the case of the structure of the connective tissue skeleton of normal and diseased myocardium. This report reviews the connective tissue matrix of the normal human myocardial tissue and the pathological myocardial fibrosis in left ventricular hypertrophy due to chronic arterial hypertension in humans and in human chronic chagasic myocarditis. The myocardial connective tissue matrix was studied employing a cell-maceration method that removes the myocardial tissue non-fibrous elements, and leaves behind a non-collapsed matrix, thus allowing a better three-dimensional view. Such information extends our knowledge of the expression of interstitial myocardial fibrous tissue in normal hearts and in hypertensive left ventricular hypertrophy and chronic chagasic myocarditis. The progressive accumulation of interstitial collagen fibers in both chronic cardiac diseases may be expected to decrease myocardial compliance and disrupt synchronous contractions of the ventricles during systole, contributing to a spectrum of ventricular dysfunction that involve either the diastolic or systolic phase of the cardiac cycle or both. In hypertensive heart disease myocardial fibrosis can be also implicated in the genesis of ventricular dysrhythmias, possible causes of sudden death among chronic hypertensive patients. Regarding chronic chagasic myocarditis, myocardial fibrosis is probably implicated in the genesis of malignant ventricular tachyarrhythmias (ventricular tachycardia and ventricular fibrillation), major causes of sudden death among patients with chronic Chagas' heart disease. The collagen distribution could interfere on the electrical properties of the myocardium. Fibrosis can block the cardiac impulse that may recycle (re-entry) through an alternative route and could slow conduction. In addition, the thick collagenous septa encompassing muscle fiber bundles could interfere with lateral impulse conduction, which would favor re-entry. Moreover, the methodology used is a useful tool to study the spatial organization of the collagen fibrils of the myocardium under normal and pathological conditions.

Schirrous invasive ductal carcinoma of the breast overexpress p53 oncoprotein

CONTEXT

Breast cancer is the most important neoplasm in adult women, and its worldwide incidence is growing. The tumoral stroma is very important for modulating the growth and invasion of the tumor itself. The relationship between these two components is not completely understood. Schirrous carcinoma is a variant of ductal invasive carcinoma in which the stroma is very desmoplastic, and the importance of this finding still a motive for debate in the literature.

OBJECTIVE

To compare the desmoplastic reactions against biological markers, such as estrogen and progesterone receptors, oncoprotein c-erbB-2 and oncoprotein p53, with the objective of studying the relationship between the tumoral stroma and epithelial cancer cells.

TYPE OF STUDY

Retrospective study.

SETTING

Cancer Hospital A C Camargo and Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.

SAMPLE

107 adult women operated because of ductal invasive carcinoma. The cases were separated into 4 groups according to the desmoplastic reaction - less than 15 per cent, between 15-50 per cent, 51-85 per cent, and more than 85 per cent fibrosis. The grade of fibrosis was determined by picrus-sirius staining and quantified by using a microscope with a stereo-imaging grid. Immunohistochemical methods were used to determine the expression of the hormonal receptors and c-erbB-2/p53 oncoprotein.

MAIN MEASUREMENTS

Extent of desmoplastic reaction versus expression of estrogen and progesterone receptors, oncoprotein c-erbB-2, and oncoprotein p53.

RESULTS

The results showed that schirrous carcinoma expresses oncoprotein p53 more frequently than other carcinomas with less extensive desmoplastic reaction. There were no differences between the grade of fibrosis and the other biological markers.

CONCLUSION

The intense stromal reaction in invasive ductal carcinoma may modulate the expression of p53. Further investigations should be made with the aim of understanding how this expression determines the proliferative activity in schirrous carcinoma, and whether this overexpression is secondary to mutation of the p53 gene or due to modulation of other molecules of the stroma.

Action of 2-nonenal and 4-hydroxynonenal on phosphoinositide-specific phosopholipase C in undifferentiated and DMSO-differentiated HL-60 cells

The promyelocytic cell line HL-60 has been used as an in vitro model to study the mechanism of action of two chemotactic aldehydes, 2-nonenal and 4-hydroxynonenal. Increasing aldehyde concentrations have been added to undifferentiated and DMSO-differentiated cells incubated at 37 degrees C and their effect on phosphoinositide-specific phospholipase C has been analysed by using a specific inositol-1,4,5-tris-phosphate assay system. Concentrations of 2-nonenal between 10(-9) and 10(-7) M significantly increased the enzymatic-activity in DMSO-differentiated HL-60 cells, while 10(-9) and 10(-8) M concentrations were active in the undifferentiated cells. 4-Hydroxynonenal was able to activate phospholipase C both in undifferentiated and DMSO-differentiated cells at concentrations ranging from 10(-8) to 10(-6) M. The concentrations of both compounds active on phospholipase C displayed a good correspondence with those which had been reported to be chemotactic towards rat neutrophils. In the case of 4-hydroxynonenal, the present results confirm its ability to activate phospholipase C, which we had previously shown in isolated neutrophil plasma membranes. The comparison of the effects of 2-nonenal and 4-hydroxynonenal on chemotaxis and phospholipase C activation suggests a common mechanism of action for both aldehydes, for which the presence of the double bond seems to be required.

Long-term survivors of heart transplantation: the Hartford Hospital experience

Heart transplantation has been a clinical program at Hartford Hospital for the past 15 years, resulting in 206 transplants. The five-year survival rate is 69% and is 43% at 10 years. The first recipient is surviving and has had full rehabilitation. Thirteen patients have survived 10 years or more. Advances in immunosuppression are ongoing and will result in further long-term survivors. Graft vasculopathy and lack of organ donation are current problems.

Is apoptosis a mechanism of cell death of cardiomyocytes in chronic chagasic myocarditis?

The micropathology of chronic Chagas' myocarditis reveals foci of myocardial cell loss associated with an inflammatory infiltrate composed predominantly of lymphomononuclear cells and interstitial fibrosis. The loss of myocardial cells, a devastating phenomenon in this cardiopathy, has been classically attributed to necrosis. In the present study we examined whether the loss of myocardial cells in human chronic Chagas' heart disease could result from cell death by apoptosis. A total of 11 cases of chronic chagasic myocarditis were studied: four hearts were obtained at autopsy within 8 h after death and seven endomyocardial biopsies were taken from chagasic patients with an arrhythmogenic form of the disease. The coronary arteries of all chagasic cases showed no obstructive lesions. The diagnosis of Chagas' disease was based on previously established criteria. Five cases were selected as controls: three hearts were obtained at autopsy within 8 h after death and two endomyocardial biopsies were taken from nonchagasic patients with normal myocardium morphology. As positive controls we used cardiac muscles of myocardial infarction and rat mammary glands on the fourth day after weaning. The TUNEL method was used to identify apoptotic cells in the myocardium. The expression of p53 protein, which directly or indirectly triggers apoptosis, was evaluated using immunohistochemical technique. A few apoptotic cells were stained in chronic chagasic hearts, both biopsy and autopsy cases. However, the stained nuclei were restricted to the mononuclear infiltrate accounting for about 0.5% of the mononuclear cells in the infiltrate. In contrast, the nuclei of cardiomyocytes in both regions bordering on and distant from the microfoci of myocardial cell loss were not stained by the TUNEL method. Moreover, the expression of the protein p53 in cardiomyocytes in chagasic hearts was absent. The results of the present study demonstrating negative in situ labeling of fragmented DNA associated with absence of expression of p53 provide support to the hypothesis that apoptosis is not the mechanism of cell death in chronic chagasic myocarditis. This reinforces the general opinion that the loss of cardiac muscle fibers in chagasic cardiopathy is produced by necrosis. On the other hand, the present results give support to the concept that apoptosis probably play a role in the clearing of lymphomononuclear cells in the inflammatory infiltrate in chronic chagasic myocarditis.

Microcirculation and Chagas' disease: hypothesis and recent results

This review focuses on studies that support the microvascular hypothesis, as well as on immunological and neurogenic mechanisms, and the role of the parasite itself, to explain further the pathology and clinical course of myocardial involvement in chagasic cardiomyopathy. The salient features of coronary microcirculation and Chagas' disease are discussed.

[Diagnostic imaging in Cushing's disease and its correlation with postsurgical clinical course]

The purpose of this paper was to assess the accuracy of computed tomography (CT) and magnetic resonance (MR) in the preoperative identification of corticotropin-secreting pituitary adenomas and to evaluate the concordance with the postoperative outcome. A total of 44 images of patients with Cushing's disease were retrospectively taken into consideration; 23 CT and 29 MR were evaluated. Patients were subdivided into remission or persistence, following the postoperative outcome and biochemical tests. In 13 out of 23 CT performed, an adenoma was found, the remaining 10 being negative. TC sensitivity was 56.5%. Twenty five MR were positive and 4 were negative. The overall sensitivity of MR in detecting ACTH-secreting adenoma was greater (86.0%, P: 0.0373, after Yates correction). After operation, 31 patients (70.5%, Cl 0.70 +/- 0.13) were considered to be in remission (27 total remission and 4 partial remission); 23 had had preoperative visualization of the pituitary tumor and 8 negative neuroradiological evaluation. Thirteen patients had persistence of disease as shown by sustained hypercotisolism in biochemical tests. In 11 of these patients, an adenoma had been preoperatively identified whereas in the remaining 2 no evidence of tumor lesion had been detected. An histologically proven tumor was found in 33 patients but findings were negative in the remaining 11 cases. Lack of histological evidence of an ACTH-secreting adenoma was more frequent in patients with persistent hypercortisolism (P < 0.0078).

IN CONCLUSION

1) MR seems to be more sensitive than CT for detecting ACTH-secreting adenomas (P: 0.037, after Yates correction); 2) no relationship was disclosed between the absence of imaging signs of adenoma and the postsurgical outcome; 3) the remission rate was significantly higher in patients with positive than in those with negative histological findings.

Fibrosis and inflammatory cells in human chronic chagasic myocarditis: scanning electron microscopy and immunohistochemical observations

The present study deals with both pathologic fibrosis and matrix connective tissue in chronic chagasic myocarditis. A total of 12 hearts were obtained at autopsy. Eight cases of chronic chagasic myocarditis were selected. Four cases without evidence of cardiac disease were used as controls. The diagnosis of chronic Chagas' heart disease was based on previously established criteria. A cell-maceration method was utilized to evaluate the spatial organization of the fibrillar collagen accumulation after removal of the myocardial tissue non-fibrous elements. The relationship between inflammatory cells identified by monoclonal antibodies and interstitial fibrosis stained with picrosirius red was assessed. Striking structural alterations of the collagen matrix in the perimysium were detected: increase in number and thickness of tendon-like structures, and markedly thickened and aggregated collagen strands. Besides, a diffuse increase in the thickness of collagen fibers surrounding individual myocytes, consisting of the endomysial matrix, mainly adjacent to the perimysium, could be observed. The dense-weave endomysial meshwork was composed of fine collagen fibrils, and it was continuous with those of adjacent myocytes, obscuring the lateral struts. Sometimes, thicker struts tethering myocytes to myocytes could be seen. These changes were associated with scattered dense scar-like foci, probably reflecting repair fibrosis associated with myocyte necrosis. Furthermore, the present results clearly showed the colocalization of foci of myocyte necrosis and degeneration and associated fibrosed areas and fibroblasts with T lymphocytes and macrophages. The accumulation of interstitial collagen fibers in chronic chagasic myocarditis may be expected to decrease myocardial compliance and disrupt synchronous contraction of the ventricles during systole, contributing to a spectrum of ventricular dysfunction that involve either the diastolic or systolic phase of the cardiac cycle or both. Myocardial fibrosis can be also implicated in the genesis of malignant ventricular tachyarrhythmias, major causes of sudden death among chronic chagasic patients. The increase in myocardial fibrosis could be directly related to an inflammatory reaction mainly composed of T lymphocytes and macrophages.

Pathologic fibrosis and connective tissue matrix in left ventricular hypertrophy due to chronic arterial hypertension in humans

OBJECTIVE

To investigate pathologic fibrosis and connective tissue matrix in left ventricular hypertrophy due to chronic arterial hypertension in humans.

DESIGN AND METHODS

Seventeen human hearts were studied. Group 1 consisted of control hearts (four hearts, weighing 280 +/- 40 g each), from subjects who had had no evidence of heart disease and for whom the diagnoses of death were noncardiac. Groups 2 (five hearts, weighing 440 +/- 50 g each), 3 (five hearts, weighing 560 +/- 50 g each), and 4 (three hearts, weighing 680 +/- 60 g each) consisted of hearts from subjects who had had a history of systemic hypertension. All hearts had no valvular deformities and no evidence of ischemic disease at the postmortem examination. A cell-maceration method was employed to evaluate the myocardial connective matrix after removal of the nonfibrous elements of myocardial tissue, leaving behind a noncollapsed matrix, thus allowing a better three-dimensional view. Myocardial tissue was also processed for conventional light microscopic and morphometric studies.

RESULTS

The minor transverse diameter of myocytes from hearts in groups 1-4 hearts were 13.7 +/- 7.8, 23.7 +/- 3.4, 26.6 +/- 3.7, and 32.8 +/- 5.8 microm, respectively. The volume fraction of fibrosis of the controls was 6.5%, whereas the volume fractions in hypertensive hearts increased progressively according to heart weight: 15.4, 22.9, and 31.1% for hearts in groups 2, 3, and 4, respectively. The most striking feature was the diffuse marked increase in amount of pericellular collagen weave fibers (endomysial matrix), parallel to the increase of heart weight. The hypertrophied myocytes were encased in a dense weave of collagen fibrils continuous with those of adjacent myocytes. The muscle fibers in hypertrophied hearts were markedly larger than normal, although this was extremely variable from an area to another. Besides, a diffuse increase in the number of thick collagen fibers constituting broad bands and sheets of collagen surrounding disorganized muscle bundles (perimysial matrix) was observed. Scattered dense scar-like foci, apparently replacing areas of myocyte loss, could be seen, mainly on the periphery of muscle bundles. This latter finding was more commonly observed among hypertrophied hearts from group 3 and, mainly, among hypertrophied hearts of group 4. Importantly, a progressive disarray of the connective tissue skeleton of the myocardium could be seen in parallel to the progressive increase of cardiac hypertrophy.

CONCLUSIONS

The progressive accumulation of interstitial collagen fibers in left ventricular hypertrophy, in parallel to an increase in heart weight, can be expected to contribute to a spectrum of ventricular dysfunction involving either the diastolic or systolic phase of the cardiac cycle, or both, that is associated with the greater than normal arrhythmogenic risk for a hypertensive heart. Moreover, the methodology used is useful for studying the spatial organization of the collagen fibrils of the myocardium under normal and pathologic conditions.

CD40 ligand is not essential for the development of cell-mediated immunity and resistance to Mycobacterium tuberculosis

It has been proposed that the induction of cellular immunity and resistance to intracellular pathogens is dependent upon CD40 ligand (CD40L). In the present study we show that this proposal is not ubiquitously supported. Mice genetically deficient in CD40L (CD40LKO) were resistant to i.v. infection with Mycobacterium tuberculosis when assessed by survival and bacteriologic burden in the spleen, liver, and lungs. Infected CD40LKO mice developed granulomas that lacked epithelioid cells and were less numerous and markedly smaller than those observed in control mice. Upon stimulation with purified protein derivative of M. tuberculosis, CD4+ T cells from infected CD40LKO mice proliferated and produced high levels of IFN-gamma but not IL-4. Finally, spleen cells from CD40LKO mice stimulated with M. tuberculosis produced IL-12, TNF, and nitric oxide levels comparable to those produced by control cells. In contrast to original proposals, these data clearly show that protective Thl immunity can be achieved against intracellular pathogens (e.g., Mycobacterium) independently of CD40L.

Infrarenal aortic coarctation and diffuse hypoplasia of the aortoiliac-femoral system

Infrarenal aortic coarctation and diffuse hypoplasia is a very uncommon vascular disease. It has been named as hypoplasia of the abdominal aorta, mid-aortic dysplasia, mid-aortic syndrome, atrophy of aorta, atresia of the terminal aorta, and atypical coarctation. The pathogenesis is still controversial. This is in part due to the fact that among the reported cases pathological studies have been rarely carried out. We recently came across an autopsy case of an adult patient with coarctation of the infrarenal aorta and severe hypoplasia of the aortoiliac-femoral system. The pathological findings found explain the pathogenesis of this particular case.

The increase of phospholipase C activity induced by orotic acid is unrelated to lipid peroxidation

Liver phospholipase-C (PL-C) activity proved to be promptly modified in rats fed with an orotic acid (OA) supplemented diet; an increased of PL-C basal activity was demonstrated after 2 days of diet. In the present work the possible involvement of lipid peroxidation was investigated, since 4-hydroxynonenal (HNE) and 4-hydroxyoctenal (HOE), two end-products of lipid peroxidation, have been shown to induce a strong stimulation of hepatic PL-C. Membrane-bound PL-C activity was evaluated together with the rate of TBArs production by liver homogenates obtained from rats fed with a diet containing 1% OA for 2 and 5 days. PL-C activity was measured by following the rate of formation of Ins-P3 from labelled PtdIns-P2 added to isolated liver membranes. TBArs production was unchanged in the livers of rats fed the OA diet, while basal and GTPgammaS-stimulated PL-C activity increased; furthermore PL-C stimulation by bombesin was deeply impaired by OA.

Aortic endothelial cell changes in the acute septicemic phase of experimental Trypanosoma cruzi infection in rats: scanning and transmission electron microscopic study

In the acute phase of Chagas' disease, the micropathology of the heart reveals a diffuse focal myocarditis, sometimes of a phlegmonous type and of an intensity not seen in any other inflammatory heart disease. Foci of myocytolytic necrosis and degeneration are seen microscopically with an intense mononuclear infiltrate associated with exudative phenomena and marked parasitism of myofibers. Abnormalities of the coronary microcirculation have been demonstrated in acute chagasic myocarditis as possible cause of transient ischemia consistent with the hypothesis of microvascular factor as a cause of the myocardial changes. Considering that the endothelium plays a key role as controller of the vessel tone regulation and vascular permeability, this investigation was carried out to study the structure of the endothelial lining of the thoracic and abdominal aorta obtained from Trypanosoma cruzi-infected rats in the acute septicemic phase by using scanning and transmission electron microscopy. The findings clearly demonstrate that the infected rats developed changes of the endothelial layer characterized by endothelial cell swelling and a few points of cell cytoplasm discontinuity appearing as holes exposing the subendothelial collagen usually associated with platelet-fibrin aggregates. These changes could disturb the generation of vasoactive substances, impairing the equilibrium between opposing forces. The exposition of the subendothelial collagen due to holes in the endothelial lining would favor platelet-fibrin aggregation. This way, the present results allow speculation that similar endothelial cells changes could be present in the microcirculation, reflecting a reduction in the protective role of the endothelium, participating in the genesis of vasospasm and platelet aggregation within coronary microvessels, and leading to the focal pathology in acute chagasic myocarditis.

Interactions between propofol and lipid mediator receptors: inhibition of lysophosphatidate signaling

As a highly lipophilic drug, propofol may interact with lipophilic domains in addition to its likely primary site of action on the gamma-aminobutyrateA) (GABA(A)) receptor. Likely candidates for such interaction are the G protein-coupled membrane receptors for lipid intercellular mediators. The phospholipid lysophosphatidate (LP) has attracted attention as such a signaling molecule. It has a variety of biological actions, including vasoconstriction. We therefore studied the interaction between propofol and the LP receptor. Intracellular Ca2+ release in response to LP was assessed by measuring C1- flux through Ca(2+)-activated C1- channels in Xenopus oocytes. The average charge movement in response to LP 10(-7)M was 2.0 +/- 0.2 microCoulombs. Propofol in Intralipid (0.01%) dose-dependently inhibited LP signaling (50% inhibitory concentration [IC50] 5.38 microM). Propofol 28 microM inhibited LP signaling by 81%. Intralipid (0.01%) was without effect. To ascertain that intracellular signaling pathways and the Ca(2+)-activated C1- channel were not affected by propofol, we tested the effects of propofol (5.6 microM) on currents induced by methylcholine (10(-7)M) in oocytes expressing the m1 muscarinic acetylcholine receptor. No inhibition was observed. As both receptors share the same intracellular signaling pathway, we conclude that clinically relevant concentrations of propofol most likely inhibit the LP receptor or its G protein. Inhibition of LP signaling may explain some of propofol's vasodilating actions.

Congenital coronary arteriovenous fistula: spontaneous rupture and cardiac tamponade

Congenital coronary arteriovenous fistula is an unusual, but not rare, coronary anomaly. Management of asymptomatic fistulas is controversial because of great variability in natural history. We describe an 82-year-old female patient with spontaneous rupture of a previously undetected left main coronary artery-to-pulmonary artery coronary arteriovenous fistula, with resulting hemopericardium and cardiac tamponade. Emergent surgical exploration and repair provided successful treatment.

Purification and characterization of the vaccinia virus deoxyuridine triphosphatase expressed in Escherichia coli

The deoxyuridine triphosphatase gene of vaccinia virus, encoded by the open reading frame F2L, was cloned into Escherichia coli and expressed under the control of a bacteriophage T7 promoter. After induction of T7 RNA polymerase by isopropyl beta-D-thiogalactopyranoside, a 16.5-kDa peptide accumulated to high levels. This 16.5-kDa protein was purified to homogeneity and characterized. Gel filtration of the purified protein revealed a trimeric native structure. Biochemical analysis revealed the enzyme to be a metalloenzyme; enzymatic activity is inhibited by EDTA. This inhibition was reversed by the addition of Mg2+, Mn2+, or Zn2+. While the enzyme activity was highly specific for dUTP with an apparent Km of 0.94 microM, inhibition studies show that 8-azido-ATP acted as a competitive inhibitor of dUTP with a Ki of approximately 173 microM. Also, protection studies demonstrated that nucleotide competitors inhibit photoincorporation of the photoaffinity analogues [gamma-32P]5-azido-dUTP and [gamma-32P]8-azido-ATP. This suggests that while catalytic activity is limited to dUTP, other nucleotides can bind the active site.

[Determination of serum aminoglycoside and vancomycin concentrations by the microbiological method in the presence of other antimicrobials]

The determination of serum concentrations of antimicrobials with a narrow therapeutic range by microbiological method requires some modifications when the patient is under combined antimicrobial therapy. The methodological conditions for the appraisal of aminoglycosides and vancomycin in the presence of other drugs were evaluated by using strains with selective sensitivity to the antimicrobial to be tested or by the adding crude extracts of beta-lactamases for the inactivation of the beta-lactam antimicrobials. These beta-lactamases were obtained from Enterobacter cloacae P99 (derepressed mutant) cultures for the inactivation of penicillins and first, second and third generation cephalosporins, as well as from Stenotrophomonas (Xanthomonas) maltophilia M 1484 cultures for the hydrolysis of imipenem. The strains allowing vancomycin appraisal and indifferent to the synergic activity of other drugs in the mixture were S. aureus M 2120, when the accompanying antimicrobials were gentamicin, ciprofloxacin or rifampicin, and E. faecalis M 2113, E. avium M 2091 and S. aureus M 2101 when the drugs in the mixture were amikacin, lincomycin or trimethoprim-sulfamethoxazole, respectively. For the appraisal of gentamicin in the presence of vancomycin or fluoroquinolones (ciprofloxacin or norfloxacin), E. coli M 1376 was the most suitable strain, while the use of K. pneumoniae ATCC 10031 was required for the appraisal of amikacin or netilmicin. When rifampicin was the accompanying antimicrobial, E. coli M 1495 turned out more adequate. E. coli M 1462 proved to be more satisfactory for gentamicin, amikacin and netilmicin dosages in samples also containing chloramphenicol, trimethoprim-sulfamethoxazole or tetracycline.

Glucocorticoids: their role on gonadal function and LH secretion

The aim of the study was to investigate gonadal function and LH reserve in patients on chronic therapy with supraphysiological doses of GC. We clinically evaluated 17 male subjects (aged 23-56 years-old) on chronic GC therapy. In four subjects (aged 23-39 years-old) randomly selected, three basal blood samples were drawn and pooled for measurement of SHBG, total, free and bioavailable testosterone. Following baseline samples, a GnRH stimulation test was performed. Starting with a priming of 5 micrograms, a bolus of 50 micrograms of GnRH was injected intravenously and samples obtained every 30 minutes for assessment of LH. Four healthy men (aged 24-28 years-old) were used as controls. Patients on steroids referred decreased libido (58%) and impotence (52%) and lower back pain (41%). Total, free and bioavailable serum testosterone were significantly lower than controls (p < 0.01, p < 0.05 and p < 0.05, respectively) while SHBG levels persisted unchanged. Baseline LH and its rise after GnRH was normal. This study shows that chronic GC administration involves gonadal function reducing sexual steroids without changes in baseline and stimulated LH secretion. In addition, the priming with physiological doses of GnRH optimizes the pituitary response to higher GnRH doses.