Urological complications in women undergoing Cesarean section for placenta accreta spectrum disorders: systematic review and meta-analysis.

OBJECTIVE: To report on the occurrence of urological complications in women undergoing Cesarean section for placenta accreta spectrum disorders (PAS). METHODS: MEDLINE, EMBASE and the Cochrane databases were searched electronically up to 1 November 2022. Studies reporting on the urological outcome of women undergoing Cesarean section for PAS were included. Two independent reviewers performed data extraction using a predefined protocol and assessed the risk of bias using the Newcastle-Ottawa scale for observational studies, with disagreements resolved by consensus.The primary outcome was the overall occurrence of urological complications. Secondary outcomes were the occurrence of any cystotomy, intentional cystotomy, unintentional cystotomy, ureteral damage, ureteral fistula and vesicovaginal fistula. All outcomes were explored in the overall population of women undergoing surgery for PAS. In addition, we performed subgroup analyses according to the type of surgery (Cesarean hysterectomy, or conservative surgery or management), severity of PAS at histopathology (placenta accreta/increta and placenta percreta), type of intervention (planned vs emergency) and number of cases per year. Random-effects meta-analyses of proportions were used to analyze the data. RESULTS: There were 62 studies included in the systematic review and 56 were included in the meta-analysis. Urological complications occurred in 15.2% (95% CI, 12.9-17.7%) of cases. Cystotomy complicated 13.5% (95% CI, 9.7-17.9%) of surgical operations. Intentional cystotomy was required in 7.7% (95% CI, 6.5-9.1%) of cases, while unintentional cystotomy occurred in 7.2% (95% CI, 6.0-8.5%) of cases. Urological complications occurred in 19.4% (95% CI, 16.3-22.7%) of cases undergoing hysterectomy and 12.2% (95% CI, 7.5-17.8%) of those undergoing conservative treatment. In the subgroup analyses, urological complications occurred in 9.4% (95% CI, 5.4-14.4%) of women with placenta accreta/increta and 38.5% (95% CI, 21.6-57.0%) of those described as having placenta percreta, and included mainly cystotomy (5.5% (95% CI, 0.6-15.1%) and 22.0% (95% CI, 5.4-45.5%), respectively). Urological complications occurred in 15.4% (95% CI, 8.1-24.6%) of cases undergoing a planned procedure and 24.6% (95% CI, 13.0-38.5%) of those undergoing an emergency intervention. In subanalysis of studies reporting on ≥ 12 cases per year, the incidence of urological complication was similar to that reported in the primary analysis. CONCLUSIONS: Women undergoing surgery for PAS are at high risk of urological complication, mainly cystotomy. The incidence of these complications was particularly high in women described as having placenta percreta at birth and in those undergoing emergency surgical intervention. The high heterogeneity between the included studies highlights the need for a standardized protocol for the diagnosis of PAS to identify prenatal imaging signs associated with the increased risk of urological morbidity at delivery. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Peripartum echocardiographic changes in women with hypertensive disorders of pregnancy.

OBJECTIVE: Hypertensive disorders of pregnancy (HDP) are associated with significant myocardial dysfunction on echocardiography. The impact of hemodynamic changes related to volume redistribution following delivery on myocardial function in women with HDP has not been evaluated systematically. The aim of this study was to compare echocardiographic findings immediately before and after delivery in women with HDP. METHODS: This was a prospective longitudinal study including 30 women with a diagnosis of HDP who underwent two consecutive transthoracic echocardiographic (TTE) examinations, before delivery and in the early postpartum period. Paired comparisons of the findings from the two assessments were performed. RESULTS: Left-ventricular (LV) concentric remodeling or hypertrophy was detected in 21 (70%) patients. There was no significant difference in cardiac morphology indices such as LV mass index (78.9 ± 16.3 g/m2 vs 77.9 ± 15.4 g/m2 ; P = 0.611) or relative wall thickness (0.45 ± 0.1 vs 0.44 ± 0.1; P = 0.453) before vs after delivery. LV diastolic function did not demonstrate any peripartum variation, with similar left-atrial volume (52.4 ± 15.3 mL vs 51.0 ± 15.6 mL; P = 0.433), lateral E' (0.12 ± 0.03 m/s vs 0.12 ± 0.03 m/s; P = 0.307) and E/E' ratio (7.9 ± 2.2 vs 7.9 ± 1.7; P = 0.934) before vs after delivery. Systolic function indices, such as LV ejection fraction (57.5 ± 3.4% vs 56.4 ± 2.1%; P = 0.295) and global longitudinal strain (-15.3 ± 2.6% vs -15.1 ± 3.1%; P = 0.582), also remained unchanged between before vs after delivery. CONCLUSIONS: Maternal hemodynamic changes associated with delivery did not influence significantly peripartum TTE indices in women with HDP. Suboptimal maternal echocardiographic findings in HDP are likely to be the consequence of chronic pregnancy cardiovascular load changes or pre-existing maternal cardiovascular impairment. Severity and persistence of myocardial dysfunction in the postpartum period may be related to the long-term maternal cardiovascular disease legacy of HDP. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Effectiveness of contingent screening for placenta accreta spectrum disorders based on persistent low-lying placenta and previous uterine surgery.

OBJECTIVES: Maternal mortality related to placenta accreta spectrum (PAS) disorders remains substantial when diagnosed unexpectedly at delivery. The aim of this study was to evaluate the effectiveness of a routine contingent ultrasound screening program for PAS. METHODS: This was a retrospective study of data obtained between 2009 and 2019, involving two groups: a screening cohort of unselected women attending for routine mid-trimester ultrasound assessment and a diagnostic cohort consisting of women referred to the PAS diagnostic service with a suspected diagnosis of PAS. In the screening cohort, women with a low-lying placenta at the mid-trimester assessment were followed up in the third trimester, and those with a persistent low-lying placenta (i.e. placenta previa) and previous uterine surgery were referred to the PAS diagnostic service. Ultrasound assessment by the PAS diagnostic service consisted of two-dimensional grayscale and color Doppler ultrasonography, and women with a diagnosis of PAS were usually managed with conservative myometrial resection. The final diagnosis of PAS was based on a combination of intraoperative clinical findings and histopathological examination of the surgical specimen. RESULTS: In total, 57 179 women underwent routine mid-trimester fetal anatomy assessment, of whom 220 (0.4%) had a third-trimester diagnosis of placenta previa. Seventy-five of these women were referred to the PAS diagnostic service because of a history of uterine surgery, and 21 of 22 cases of PAS were diagnosed correctly (sensitivity, 95.45% (95% CI, 77.16-99.88%) and specificity, 100% (95% CI, 99.07-100%)). Univariate analysis demonstrated that parity ≥ 2 (odds ratio (OR), 35.50 (95% CI, 6.90-649.00)), two or more previous Cesarean sections (OR, 94.20 (95% CI, 22.00-656.00)) and placenta previa (OR, 20.50 (95% CI, 4.22-369.00)) were the strongest risk factors for PAS. In the diagnostic cohort, there were 173 referrals, with one false-positive and three false-negative diagnoses, resulting in a sensitivity of 96.63% (95% CI, 90.46-99.30%) and a specificity of 98.81% (95% CI, 93.54-99.97%). CONCLUSIONS: A contingent screening strategy for PAS is both feasible and effective in a routine healthcare setting. When linked to a PAS diagnostic and surgical management service, adoption of such a screening strategy has the potential to reduce the maternal morbidity and mortality associated with this condition. However, larger prospective studies are necessary before implementing this screening strategy into routine clinical practice. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Eficacia de la detección contingente para los trastornos del espectro de la placenta acreta a partir de la placenta baja persistente y en la cirugía uterina previa OBJETIVOS: La mortalidad materna relacionada con los trastornos de la gama espectral de la placenta acreta (EPA) sigue siendo considerable cuando se diagnostica de forma inesperada en el momento del parto. El objetivo de este estudio fue evaluar la efectividad de un programa rutinario de detección contingente mediante ecografía para el EPA. MÉTODOS: Este fue un estudio retrospectivo de datos obtenidos entre 2009 y 2019, en el que participaron dos grupos: una cohorte de detección de mujeres no seleccionadas que acudieron a la evaluación ecográfica rutinaria de mitad de trimestre y una cohorte de diagnóstico, integrada por mujeres remitidas al servicio de diagnóstico del EPA con un presunto diagnóstico del EPA. En la cohorte de detección, a las mujeres con una placenta baja en la evaluación de mitad de trimestre se les hizo un seguimiento en el tercer trimestre, y a aquellas con una placenta baja persistente (es decir, placenta previa) que habían tenido cirugía uterina previa se las remitió al servicio de diagnóstico del EPA. La evaluación ecográfica por el servicio de diagnóstico del EPA consistió en una ecografía Doppler bidimensional en escala de grises y en color, y a las mujeres con diagnóstico del EPA se las trató habitualmente con una resección conservadora del miometrio. El diagnóstico final del EPA se basó en una combinación de indicadores clínicos intraoperatorios y el examen histopatológico de la muestra quirúrgica. RESULTADOS: En total, 57179 mujeres se sometieron a una evaluación rutinaria de la anatomía fetal a mitad del trimestre, de las cuales a 220 (0,4%) se les diagnosticó con placenta previa en el tercer trimestre. Setenta y cinco de estas mujeres fueron remitidas al servicio de diagnóstico del EPA, debido a su historial de cirugía uterina, y 21 de los 22 casos de EPA fueron diagnosticados correctamente (sensibilidad, 95,45% (IC 95%, 77,16-99,88%) y especificidad, 100% (IC 95%, 99,07-100%)). El análisis univariante demostró que la paridad ≥2 (razón de momios (RM), 35,50 (IC 95%, 6,90-649,00)), dos o más cesáreas previas (RM, 94,20 (IC 95%, 22,00-656,00)) y la placenta previa (RM, 20,50 (IC 95%, 4,22-369,00)) fueron los factores de riesgo más fuertes para el EPA. En la cohorte de diagnóstico, se remitió a 173 mujeres, entre las cuáles hubo un diagnóstico de falso-positivo y tres diagnósticos de falsos-negativos, lo que dio como resultado una sensibilidad del 96,63% (IC 95%, 90,46-99,30%) y una especificidad del 98,81% (IC 95%, 93,54-99,97%). CONCLUSIONES: La adopción de una estrategia de detección contingente para el EPA es tanto factible como eficaz en un entorno de atención sanitaria rutinaria. Cuando se asocia a un servicio de diagnóstico y gestión quirúrgica del EPA, la adopción de esa estrategia de detección podría reducir la morbilidad y la mortalidad maternas asociadas a esta afección. Sin embargo, se necesitan estudios prospectivos más amplios antes de aplicar esta estrategia de detección en la práctica clínica habitual. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early maternal Zika infection predicts severe neonatal neurological damage: results from the prospective Natural History of Zika Virus Infection in Gestation cohort study.

OBJECTIVE: To define the prevalence of adverse outcomes of maternal infection in a large cohort of ZIKV-infected Brazilian women and their infants. DESIGN: Prospective population-based cohort study. SETTING: Ribeirão Preto's region's private and public health facilities. POPULATION: Symptomatic ZIKV-infected mothers and their infants. METHODS: Prenatal/early neonatal data were obtained for all mother-child pairs. A subgroup of infants had cranial ultrasonography, eye fundoscopy, hearing and neurological examinations and Bayley III screening tests within 3 months of age. MAIN OUTCOME MEASURES: Prevalence of pregnancy losses and anomalies detected at birth or within 3 months according to the gestational age of infection. RESULTS: Overall, 511 ZIKV-infected women were identified from a total of 1116 symptomatic women; as there were two twins, there were a total of 513 fetuses included. Of these, 13 (2.5%; 95% CI 1.5-4.3) presented with major signs of congenital Zika syndrome (CZS). Of the 511 women, there were 489 livebirths and 24 (4.7%) pregnancy losses (20 miscarriages and four stillbirths). ZIKV-related anomalies occurred in the offspring of 42/511 (8.2%) mothers. Microcephaly or other CNS malformations were diagnosed in 1/4 (25.0%) stillbirths and in 19/489 (3.9%; 95% CI 2.5-5.9) of the liveborn infants. Fetal abnormalities were 14.0 (95% CI 7.6-26.0) times more likely with gestational infection occurring in ≤11 weeks. On follow up of 280 asymptomatic infants, 2/155 (1.3%) had eye abnormalities, 1/207 (0.5%) had CNS imaging findings and 16/199 (8%) presented neurological alert signs. CONCLUSIONS: This prospective population-based study represents the largest Brazilian cohort study of ZIKV in pregnancy. Congenital anomalies potentially associated with CZS are less frequent than previously thought. There is a strong association between the gestational age of infection (≤11 weeks) and a poorer early infant prognosis. A notable proportion of apparently asymptomatic newborns can present with subclinical findings within 3 months of age. TWEETABLE ABSTRACT: ZIKV and pregnancy: adverse outcomes are less common, more prevalent for first-trimester infections, and potentially subclinical.

Periodate-oxidized ATP modulates macrophage functions during infection with Leishmania amazonensis.

Previously, we showed that treating macrophages with ATP impairs the intracellular growth of Leishmania amazonensis, and that the P2X7 purinergic receptor is overexpressed during leishmaniasis. In the present study, we directly evaluated the effect of periodate-oxidized ATP (oATP) on parasite control in Leishmania-infected macrophages. We found that oATP impaired the attachment/entrance of L. amazonensis promastigotes to C57BL/6 mouse macrophages in a P2X7 receptor-independent manner, as macrophages from P2X7(-/-) mice were similarly affected. Although oATP directly inhibited the growth of axenic promastigotes in culture, promoted rapid ultrastructural alterations, and impaired Leishmania internalization by macrophages, it did not affect intracellular parasite multiplication. Upon infection, phagosomal acidification was diminished in oATP-treated macrophages, accompanied by reduced endosomal proteolysis. Likewise, MHC class II molecules expression and ectoATPase activity was decreased by oATP added to macrophages at the time of parasite infection. These inhibitory effects were not due to a cytotoxic effect, as no additional release of lactate dehydrogenase was detected in culture supernatants. Moreover, the capacity of macrophages to produce nitric oxide and reactive oxygen species was not affected by the presence of oATP during infection. We conclude that oATP directly affects extracellular parasite integrity and macrophage functioning.

Predictors of adverse pregnancy outcomes in women infected with HIV in Latin America and the Caribbean: a cohort study.

OBJECTIVE: To examine maternal characteristics associated with adverse pregnancy outcomes among women infected with HIV. DESIGN: Prospective cohort study. SETTING: Multiple sites in Latin America and the Caribbean. POPULATION: Women infected with HIV enrolled in the Perinatal (2002-2007) and the Longitudinal Study in Latin American Countries (LILAC; 2008-2012) studies of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) International Site Development Initiative (NISDI). METHODS: Frequencies of adverse pregnancy outcomes assessed among pregnancies. Risk factors investigated by logistic regression analysis. MAIN OUTCOME MEASURES: Adverse pregnancy outcomes, including preterm delivery (PT), low birthweight (LBW), small for gestational age (SGA), stillbirth (SB), and neonatal death. RESULTS: Among 1512 women, 1.9% (95% confidence interval, 95% CI, 1.3-2.7) of singleton pregnancies resulted in a stillbirth and 32.9% (95% CI 30.6-35.4) had at least one adverse pregnancy outcome. Of 1483 singleton live births, 19.8% (95% CI 17.8-21.9) were PT, 14.2% (95% CI 12.5-16.1) were LBW, 12.6% (95% CI 10.9-14.4) were SGA, and 0.4% (95% CI 0.2-0.9) of infants died within 28 days of birth. Multivariable logistic regression modelling indicated that the following risk factors increased the probability of having one or more adverse pregnancy outcomes: lower maternal body mass index at delivery (odds ratio, OR, 2.2; 95% CI 1.4-3.5), hospitalisation during pregnancy (OR 3.3; 95% CI 2.0-5.3), hypertension during pregnancy (OR 2.7; 95% CI 1.5-4.8), antiretroviral use at conception (OR 1.4; 95% CI 1.0-1.9), and tobacco use during pregnancy (OR 1.7; 95% CI 1.3-2.2). The results of fitting multivariable logistic regression models for PT, LBW, SGA, and SB are also reported. CONCLUSIONS: Women infected with HIV had a relatively high occurrence of adverse pregnancy outcomes, and some maternal risk factors were associated with these adverse pregnancy outcomes. Interventions targeting modifiable risk factors should be evaluated further.

A new mammography dosimetric phantom.

Breast phantoms produced with tissue-equivalent materials are used in an attempt to simulate glandular and adipose tissues, in terms of X-ray attenuation and density. In this work, a set of breast tissue-equivalent phantoms (BTE phantoms) with semicircular shapes of different thicknesses and compositions were produced. Such phantoms may be used in the measurement of the incident air kerma (K(i)) and the mean glandular dose (D(G)) delivered to patients undergoing mammography. To characterise the materials used to produce the phantoms, a series of 17-keV X-ray attenuation coefficient measurements were performed. The carbon-nitrogen-hydrogen elemental composition and the densities of the tissue-equivalent materials were also determined and compared with values available in the literature. Linear attenuation coefficients of 0.724 and 0.923 cm(-1) were determined, respectively, for adipose and glandular tissues. Such values agree with data available in the literature. On the basis of the results obtained in this work, it is suggested that BTE phantoms are used instead of polymethyl methacrylate phantoms to select exposure parameters (kV, mAs and target/filter combination) specific for breast glandularities from 0 to 50 % in the optimisation of doses in mammography.

Action of antimicrobial substances produced by different oil reservoir Bacillus strains against biofilm formation.

Microbial colonization of petroleum industry systems takes place through the formation of biofilms, and can result in biodeterioration of the metal surfaces. In a previous study, two oil reservoir Bacillus strains (Bacillus licheniformis T6-5 and Bacillus firmus H(2)O-1) were shown to produce antimicrobial substances (AMS) active against different Bacillus strains and a consortium of sulfate-reducing bacteria (SRB) on solid medium. However, neither their ability to form biofilms nor the effect of the AMS on biofilm formation was adequately addressed. Therefore, here, we report that three Bacillus strains (Bacillus pumilus LF4 -- used as an indicator strain, B. licheniformis T6-5, and B. firmus H(2)O-1), and an oil reservoir SRB consortium (T6lab) were grown as biofilms on glass surfaces. The AMS produced by strains T6-5 and H(2)O-1 prevented the formation of B. pumilus LF4 biofilm and also eliminated pre-established LF4 biofilm. In addition, the presence of AMS produced by H(2)O-1 reduced the viability and attachment of the SRB consortium biofilm by an order of magnitude. Our results suggest that the AMS produced by Bacillus strains T6-5 and H(2)O-1 may have a potential for pipeline-cleaning technologies to inhibit biofilm formation and consequently reduce biocorrosion.

Hydatid cyst of the cardiac interventricular septum: report of two cases.

Cardiac hydatid cysts are rare and represent less than 2% of all hydatid cases. They can occur as part of a widespread systemic infection or as an isolated event. Cardiac hydatid cysts rarely involve the interventricular septum. Here, we present two cases of cardiac hydatid disease in which one patient had the lesion in the interventricular septum and the other in both the interventricular septum and the apex of the heart. A brief overview of the disease and the role of echocardiography, dynamic enhanced multidetector computed tomography (MDCT) and MRI imaging in establishing the diagnosis are discussed.

Production of antimicrobial substances by Bacillus subtilis LFE-1, B. firmus HO-1 and B. licheniformis T6-5 isolated from an oil reservoir in Brazil.

AIMS: Forty Bacillus strains isolated from a Brazilian oil reservoir were tested against each other to select strains producing antimicrobial substances (AMS). Three strains, Bacillus subtilis (LFE-1), Bacillus firmus (H2O-1) and Bacillus licheniformis (T6-5), were selected due to their ability to inhibit more than 65% of the Bacillus strains tested. These three strains were also investigated for their capability to inhibit sulphate-reducing bacteria (SRB). Furthermore, physiological and biochemical characteristics of the antimicrobial compounds produced by the selected strains were determined. METHODS AND RESULTS: Among the forty strains tested, 36 (90%) strains were able to inhibit at least one Bacillus strain used as indicator in plate assays and three of them (LFE-1, T6-5 and H2O-1) were able to inhibit 65, 70 and 97.5% of the 40 strains studied here respectively. Clear zones of inhibition were observed when H2O-1 was tested against SRB-containing consortium T6-lab and Desulfovibrio alaskensis strain NCIMB 13491, while strain T6-5 was able to inhibit only the D. alaskensis strain. The three substances showed to be insensitive to different enzymes and chemicals, were heat stable and the substances produced by strains T6-5 and H2O-1 were active over a wide pH range. CONCLUSIONS: Three different AMS produced by Bacillus strains from an oil reservoir, two of them with activity against SRB, are presented here. SIGNIFICANCE AND IMPACT OF THE STUDY: The preliminary characterization of these AMS points to their potential use as biocides in the petroleum industry for controlling problems associated with SRB.

Increased Trypanosoma cruzi invasion and heart fibrosis associated with high transforming growth factor beta levels in mice deficient in alpha(2)-macroglobulin.

Trypanosoma cruzi proteinases are involved in host cell invasion in human patients and in mouse models. In mice, murine alpha(2)-macroglobulin (MAM) and murinoglobulin are circulating plasma proteinase inhibitors that also have important roles in inflammation and immune modulation. To define their role in experimental Chagas disease, we investigated the susceptibility to T. cruzi infection of mice that are deficient only in alpha2-macroglobulins (AM-KO) or in both MAM and monomeric murinoglobulin-1 (MM-KO), relative to the wild type (WT). Despite the high parasite load, parasitemia was lower in AM-KO and MM-KO mice than in WT mice. Nevertheless, we observed a significantly higher parasite load in the hearts of AM-KO and MM-KO mice, i.e., more amastigote nests and inflammatory infiltrates than in WT mice. This result demonstrates a protective role for MAM in the acute phase of murine T. cruzi infection. We further demonstrated in vitro that human alpha2-macroglobulins altered the trypomastigote morphology and motility in a dose-dependent way, and that also impaired T. cruzi invasion in cardiomyocytes. Finally, we demonstrated that the levels of transforming growth factor beta in AM-KO mice increased significantly in the third week postinfection, concomitant with high amastigote burden and important fibrosis. Combined, these in vivo and in vitro findings demonstrate that the MAM contribute to the resistance of mice to acute myocarditis induced by experimental T. cruzi infection.

Dissection of the intracranial internal carotid artery producing isolated oculomotor nerve palsy with sparing of pupil.

Dissection of the internal carotid artery usually occurs in the cervical segment, but rarely may involve the artery in the intracranial course (1). The clinical course of intracranial dissection is often catastrophic, with rapid onset of profound neurological deficit, as a result of middle and/or anterior cerebral artery involvement. When this occurs the mortality rate is generally considered high. We describe a case of intracranial internal carotid artery dissection following trivial trauma presented with an isolated painful pupillary sparing oculomotor nerve palsy.

1H MR spectroscopy evidence for the varied nature of asymptomatic focal brain lesions in neurofibromatosis type 1.

We present the MRI and 1H MR spectroscopy findings in six patients with neurofibromatosis type 1 (NF1) and asymptomatic focal brain lesions. Variations in imaging appearances were seen, including regression of a previously identified lesion. MR spectra for the lesions and corresponding areas of normal brain show significant differences. The lesions could be separated into two groups, one demonstrating only slight metabolite ratio changes relative to normal brain and the other group showing significant increase in choline and decrease in N-acetyl aspartate. The lesion which regressed fell into the second group. These findings are not in agreement with those previously reported and provide evidence for the varied and possibly transient nature of these asymptomatic lesions. The spectroscopy findings suggest that metabolite changes may be present without visible changes on MRI.

Trypanosoma cruzi: acute infection affects expression of alpha-2-macroglobulin and A2MR/LRP receptor differently in C3H and C57BL/6 mice.

Although a complete cellular and humoral immune response is elicited in Chagas' disease, recent data suggest that other natural elements of innate immunity may also contribute to the initial host primary defense. alpha-Macroglobulins are a family of plasma proteinase inhibitors that are acute-phase reactants in Trypanosoma cruzi-infected mice and humans. Mice contain a tetrameric alpha-2-macroglobulin (MAM) and a monomeric murinoglobulin (MUG). Heterogeneity in their reactions was observed in murine T. cruzi-infected plasma A2M levels despite an overall increase. In addition, up-regulation of the A2M receptor (A2MR/LRP) was observed in peritoneal macrophages during T. cruzi infection. Here, we show that during T. cruzi infection (Y strain), the MAM and MUG hepatic mRNA levels and the corresponding plasma protein levels were up-regulated in C3H and C57BL/6 (B6) mice, but with different kinetics. On the contrary, A2MR/LRP mRNA levels increased in acutely infected C3H mice, but decreased in B6 mice, in both liver and heart. Immunocytochemistry of infected B6 heart cryosections confirmed a less intense endothelium labeling by the fluoresceinated ligand for A2MR/LRP. On the other hand, infected B6 spleen cells displayed higher F-A2M-FITC binding and MAC1 expression, confirming higher A2MR/LRP expression in macrophages. In uninfected mice, as well as after T. cruzi infection, higher A2M plasma levels were measured in C3H mice than in B6 mice. The lower tissue T. cruzi parasitism found in C3H-infected mice could reflect an inhibitory effect of A2M on parasite invasion. Our present data further contribute to clarifying aspects of the role of A2MR/LRP in a model of acute Chagas' disease in different mouse strains.

Genetic alterations in Ki-ras and Ha-ras genes in juvenile nasopharyngeal angiofibromas and head and neck cancer.

CONTEXT: Ras gene mutations have been associated to a wide range of human solid tumors. Members of the ras gene family (Ki-ras, Ha-ras and N-ras) are structurally related and code for a protein (p21) known to play an important role in the regulation of normal signal transduction and cell growth. The frequency of ras mutations is different from one type of tumor to another, suggesting that point mutations might be carcinogen-specific. OBJECTIVES: To study the occurrence of Ki-ras and Ha-ras mutations. We also studied the relative level of Ha-ras mRNA in 32 of the head and neck tumors. DESIGN: Case series. SETTING: University referral unit. PARTICIPANTS: 60 head and neck tumors and in 28 Juvenile Nasopharyngeal Angiofibromas (JNA). DIAGNOSTIC TEST: Using PCR-SSCP we examined the occurrence of Ki-ras and Ha-ras mutations. The relative level of Ha-ras mRNA was examined by Northern blot analysis. RESULTS: None of the head and neck tumors or JNA samples showed evidence of mutations within codons 12, 13, 59 and 61 of Ki-ras or Ha-ras genes. However, 17 (53%) of the tumors where gene expression could be examined exhibited increased levels of Ha-ras mRNA compared with the normal tissue derived from the same patient. CONCLUSIONS: Our results demonstrate for the first time that mutations of Ki-ras and Ha-ras genes are not associated with the development of JNA and confirm previous reports indicating that activating ras mutations are absent or rarely involved in head and neck tumors from western world patients. Furthermore, our findings suggest that overexpression of Ha-ras, rather than mutations, might be an important factor in the development and progression of head and neck tumors.

Detection of alpha-macroglobulin in the heart of mice infected with Trypanosoma cruzi.

The aim of this work was to investigate the presence of alpha-macroglobulin (AM) in the heart of mice during acute experimental Chagas' disease and to study its localization as related to the presence of the parasite and/or to their antigens. Frozen heart tissue sections obtained from Swiss albino male mice at different days postinfection with Trypanosoma cruzi were examined for triple immunofluorescence in response to parasite antigen (green), AM (red), and nuclei (blue) from both cells. AM was found in the heart of all the infected animals studied. Parasites were seen arranged in nests inside heart muscle cells. Usually, AM staining corresponded in position to parasite nests and to their antigens spread in large areas of the myocardium. The most intense staining of AM was observed at days 9 and 11 postinfection, when the highest tissue-infection level occurs. These observations relate the presence of AM to that of T. cruzi antigen in the same areas of the inflamed myocardium of the chagasic animals.

Alpha-2-macroglobulin receptor is differently expressed in peritoneal macrophages from C3H and C57/B16 mice and up-regulated during Trypanosoma cruzi infection.

Chagas' disease is caused by the protozoan Trypanosoma cruzi. The acute phase of T. cruzi infection, which can be conveniently studied in mouse models, is thought to be a determinant of survival and of the pathological features of the chronic phase. With regard to the occurrence of early death and parasitaemia levels C3H and C57/B16 mice are classically classified as 'susceptible' and 'resistant' to T. cruzi infection, respectively. Alpha-2-macroglobulin (A2M) is a physiological proteinase inhibitor found in tissues and in the plasma of mammals. Previous studies showed that A2M plasma levels increase in C3H mice acutely infected by T. cruzi but do not change in C57/B16 mice. This difference might involve two possible phenomena, concerning A2M synthesis and/or clearance by its receptor (A2M-R). In this study, we examined by flow cytometry the binding of A2M-trypsin conjugated with FITC to macrophages from normal and T. cruzi-infected C3H and C57/B16 mice. Our present results show for the first time that A2M-R is expressed more (by approximately 33%) in the surface of cells from normal C57/B16 as compared to C3H mice. We also show that A2M-R expression is up-regulated in both strains during acute T. cruzi infection, but at higher levels and earlier in C57/B16 mice. At the same time, peritoneal cells become activated as judged by: (1) increase of their size and granularity; (2) gradual increase of Fc gamma RII/III expression assayed by 2.4G2 binding; (3) down-modulation of F4/80 binding, a mAb that recognizes an antigen typically expressed in resident macrophages. Finally, our results indicate that as macrophages become activated in vivo a higher expression of A2M-R is observed.