Esophageal atresia with tracheoesophageal fistula: two case reports.

BACKGROUND: The incidence of esophageal atresia with tracheoesophageal fistula is 1 out of 3000-5000 live births. Its incidence in lower middle income countries is not known. The infants usually present with excessive secretions or choking while feeding and are at risk for aspiration. The outcome of these infants in lower middle income countries is not encouraging due to delays in referral, sepsis at presentation requiring preoperative stabilization, postoperative complications such as anastomosis leaks, pneumonia, and pneumothorax. CASE PRESENTATION: We present two African babies who were term infants at age 2 days (male) and 5 days (female) with diagnosis of esophageal atresia and tracheoesophageal fistula. The 5-day-old infant required preoperative stabilization due to sepsis and delayed surgery with a poor postoperative outcome. The 2-day-old infant was preoperatively stable and had a good postoperative outcome. The challenges faced in management of these two cases have been highlighted. CONCLUSION: Outcome of infants with esophageal atresia and tracheoesophageal fistula in lower middle income countries is not encouraging due to delays in referral and poor postoperative healing attributed to sepsis and recurrent pneumothorax. Timely referral, preoperative condition of the infant, and timely management has shown to be a contributory factor for an improved outcome.

"I abandoned my job to look after my baby." Understanding the unpriced cost of care of a preterm infant: Caregivers' lived experiences.

BACKGROUND: Preterm birth is associated with life-long cost implications on the infant, family, health system, and society at large. The costs related to lost productivity at contributions at work during care of preterm infants are difficult to measure. We aimed to explore and document the unpriced costs parents incur following birth of a preterm infant in the first year of life in a low resource setting. METHODS: Thirty-nine mothers and five fathers of preterm infants who had ever attended the preterm follow-up clinic after discharge from Mulago National Referral Hospital, were included in a qualitative study between November 2019 and February 2020. Participants were purposively selected, and data were collected using four focused group discussions with mothers and in-depth interviews with the fathers lasting 30-70 minutes each. These were audio-recorded, transcribed and translated. The data were manually analysed using the thematic approach. FINDINGS: Three themes were generated: i) complex nature of the infant, ii) time to care for the infant, iii) mother as the predominant caregiver. The parents perceived preterm infants as delicate, complicated and their care more costly compared to those born at term. Expressions of need for time to care for their infants, frequent hospital visits and readmission were raised. Availability of the mother as the predominant caregiver some of whose roles cannot be delegated and their experiences following return to work after birth of a preterm were cited by the participants. CONCLUSION: The results highlight the unpriced costs incurred by the parents through disruption of the work pattern due to the actual and perceived needs of a preterm infant and time to care in a low resource setting. We recommend guidance on financial planning, development of policies and programs on social and financial support for parents and future studies on indirect costs of preterm care.

Late diagnosis of congenital diaphragmatic hernia: a case report.

BACKGROUND: Congenital diaphragmatic hernia beyond the neonatal period is not uncommon. Its diagnosis in infancy and early childhood poses a challenge owing to different clinical presentation ranging from gastrointestinal to respiratory symptoms. These neonates are usually misdiagnosed as having pneumonia until radiological imaging picks up the defect during routine scan for worsening respiratory symptoms. In high-income countries, the survival rate for these patients has been reported to be high, while in Sub-Saharan Africa the survival rate is still low due to delayed diagnosis, delayed referral, and hence delayed management. CASE REPORT: We present an African male baby from non-consanguineous parents, 6 weeks old, diagnosed with congenital diaphragmatic hernia at 6 weeks of age after failure to respond to antibiotics for suspected pneumonia. Despite attempts at management, he died at 5 weeks post surgery. CONCLUSION: Our case emphasizes the importance of early clinical suspicion and early detection for a differential diagnosis of congenital diaphragmatic hernia in infants who present with respiratory symptoms not responding to antibiotics or recurrent pneumonia, and improving the availability of imaging in primary care facilities to diagnose such defects early and manage them accordingly.

CPAP failure in the management of preterm neonates with respiratory distress syndrome where surfactant is scarce. A prospective observational study.

BACKGROUND: The mainstay in the management of preterm neonates with respiratory distress syndrome (RDS) include early Continuous Positive Airway Pressure (CPAP), timely surfactant replacement and mechanical ventilation. Preterm neonates with RDS who fail CPAP are at higher risk for chronic lung disease as well as death. Unfortunately, in low resource settings CPAP may be the only treatment available for these neonates. OBJECTIVE: To determine the prevalence of CPAP failure among premature newborns with RDS and associated factors. METHODS: We conducted a prospective observational study over the first 72 h of life on 174 preterm newborns with RDS receiving CPAP at Muhimbili National Hospital (MNH). At MNH newborns with Silverman Andersen Score (SAS) of ≥ 3 are commenced on CPAP; surfactant and mechanical ventilation are very scarce. Study newborns not maintaining oxygen saturation > 90% or with SAS score ≥ 6 despite being on 50% oxygen and PEEP of 6 cmH2O and those with > 2 episodes of apnoea needing stimulation or positive pressure ventilation in 24 h were considered as CPAP failure. The prevalence of CPAP failure was determined as a percentage and factors associated were determined by logistic regression. A p-value of < 0.05 was considered significant and 95% confidence interval was used. RESULTS: Of the enrolled newborns, 48% were male and 91.4% were in-born. The mean gestational age and weight were 29 weeks (range 24-34 weeks) and 1157.7 g (range 800-1500 g) respectively. Of the mothers 44 (25%) received antenatal corticosteroids. Overall CPAP failure was 37.4% and among those weighing ≤ 1200g, it was 44.1% . Most failure occurred within the first 24 h. No factor was identified to be independently associated with CPAP failure. Mortality among those who failed CPAP was 33.8% and 12.8% among those who did not. CONCLUSIONS: In resource limited settings like ours with low up take of antenatal corticosteroids and scarce surfactant replacement a significant portion of preterm neonates especially those weighing ≤ 1200 g with RDS fail CPAP therapy.

Early outcomes of preterm neonates with respiratory distress syndrome admitted at Muhimbili National Hospital, a prospective study.

BACKGROUND: Respiratory distress syndrome (RDS) is one of the commonest complication preterm neonates suffer and accounts for a significant morbidity and mortality in low and middle income countries (LMICs). Addressing RDS is therefore crucial in reducing the under 5 mortality in LMICs. This study aimed at describing early outcomes (death/survival) of preterm neonates with RDS and identify factors associated with the outcomes among neonates admitted at Muhimbili national hospital, Tanzania. METHODS: Between October 2019 and January 2020 we conducted a prospective study on 246 preterm neonates with RDS at Muhimbili National Hospital. These were followed up for 7 days. We generated Kaplan-Meier survival curve to demonstrate time to death. We performed a cox regression analysis to ascertain factors associated with outcomes. The risk of mortality was analyzed and presented with hazard ratio. Confidence interval of 95% and P-value less than 0.05 were considered as significant. RESULTS: Of the 246 study participants 51.6% were male. The median birth weight and gestational age of participants (Inter-Quartile range) was 1.3 kg (1.0, 1.7) and 31 weeks (29, 32) respectively. Majority (60%) of study participants were inborn. Only 11.4% of mothers of study participants received steroids. Of the study participants 49 (20%) received surfactant. By day 7 of age 77/246 (31.3%) study participants had died while the majority of those alive 109/169 (64.5%) continued to need some respiratory support. Factors independently associated with mortality by day 7 included birth weight of < 1500 g (AHR = 2.11 (1.16-3.85), CI95%; p = 0.015), lack of antenatal steroids (AHR = 4.59 (1.11-18.9), CI95%; p = 0.035), 5th minute APGAR score of < 7 (AHR = 2.18 (1.33-3.56), CI95%; p = 0.002) and oxygen saturation < 90% at 6 hours post admission (AHR = 4.45 (1.68-11.7), CI95%; p = 0.003). CONCLUSION: Our study reports that there was high mortality among preterm neonates admitted with RDS mainly occurring within the first week of life. Preterm neonates with very low birth weight (VLBW), whose mother did not receive antenatal steroid, who scored < 7 at 5th minute and whose saturation was < 90% at 6 hours were at higher risk of dying. There is need to scale up antenatal corticosteroids, neonatal resuscitation training and saturation monitoring among preterm neonates with RDS.

Limited resources restrict the provision of adequate neonatal respiratory care in the countries of Africa.

AIM: Over two thirds of newborn deaths occur in Africa and South Asia, and respiratory failure is a major contributor of these deaths. The exact availability of continuous positive airway pressure (CPAP) and surfactant in Africa is unknown. The aim of this study was to describe the availability of newborn respiratory care treatments in the countries of Africa. METHODS: Surveys, in English, French and Portuguese, were sent to neonatal leaders in all 48 continental countries and the two islands with populations over 1 million. RESULTS: Forty-nine (98%) countries responded. Twenty-one countries reported less than 50 paediatricians, and 12 countries had no neonatologists. Speciality neonatal nursing was recognised in 57% of countries. Most units were able to provide supplemental oxygen. CPAP was available in 63% and 67% of the most well-equipped government and private hospitals. Surfactant was available in 33% and 39% of the most well-equipped public and private hospitals, respectively. Availability of CPAP and surfactant was greatly reduced in smaller cities. Continuous oxygen saturation monitoring was only available in 33% of countries. CONCLUSION: The availability of proven life-saving interventions in Africa is inadequate. There is a need to sustainably improve availability and use of these interventions.

Growth of preterm very low birth weight infants discharged with weight of less than 1500grams.

Early discharge of preterm very low birth weight (VLBW) infants is at times inevitable in low resource settings. The implication of such practice on the growth of this high-risk population is not known. We conducted a retrospective chart review to describe the growth of preterm VLBW infants discharged with a weight of less than 1500 g. OBJECTIVES: To describe the growth of discharged preterm VLBW infants over the first 12 weeks. METHOD: Between June 2013 and January 2014; 164 discharged preterm VLBW infants were followed up for 3 months. Among the survivors (132), we identified 111 infant records for this study. Relevant data was entered in STATA for analysis. Growth percentiles were determined at approximately 4 weeks, 8 weeks, and 12 weeks post-discharge using the intergrowth 21st growth charts. Growth velocities were computed using the 2-point average weight model. Regression analysis was used to identify factors associated with growth failure. Growth failure was defined as occipital frontal circumference (OFC), weight, and length < 10th centile by 12 weeks post-discharge. P-value of < 0.05 was considered significant at a 95% confidence interval. RESULTS: Among the study infants the median gestational age and weight at birth were 32 weeks (range 28-35 weeks) and 1250 g(range 850-1500 g) respectively; 60/111(54%) were Small for Gestational Age (SGA). The median discharge postmenstrual age (PMA) was 34 weeks (range 30-38 weeks) and weight was 1140 g (range 830-1490 g). The majority 88.2% had not recovered birth weight at discharge of whom 59.1% recovered by 2 weeks and 40.9% recovered between 2 and 4 weeks after discharge. By 12 weeks post-discharge the median PMA and weight were 46 weeks (range 37-51 weeks),and 3110 g (range 1750-5000 g) respectively, 38.7% of the infants had growth failure and 36.9% had OFC <3rd centile. Growth velocity < 15 g/kg/d in the first 4 weeks (OR 3.8, p 0.010) and subsequent 4 weeks (OR 2.5, p 0.049) post-discharge were independently associated with growth failure. CONCLUSION: Slow birth weight recovery was observed and growth failure was prevalent by 12 weeks post-discharge with more than a third having severe microcephaly. Poor post-discharge growth velocity was associated with subsequent growth failure. RECOMMENDATIONS: Growth velocity monitoring among preterm VLBW infants should be emphasized. The implication and interventions of this early growth failure needs to be explored.

Protective role of soluble adenylyl cyclase against reperfusion-induced injury of cardiac cells.

AIMS: Disturbance of mitochondrial function significantly contributes to the myocardial injury that occurs during reperfusion. Increasing evidence suggests a role of intra-mitochondrial cyclic AMP (cAMP) signaling in promoting respiration and ATP synthesis. Mitochondrial levels of cAMP are controlled by type 10 soluble adenylyl cyclase (sAC) and phosphodiesterase 2 (PDE2), however their role in the reperfusion-induced injury remains unknown. Here we aimed to examine whether sAC may support cardiomyocyte survival during reperfusion. METHODS AND RESULTS: Adult rat cardiomyocytes or rat cardiac H9C2 cells were subjected to metabolic inhibition and recovery as a model of simulated ischemia and reperfusion. Cytosolic Ca2+, pH, mitochondrial cAMP (live-cell imaging), and cell viability were analyzed during a 15-min period of reperfusion. Suppression of sAC activity in cardiomyocytes and H9C2 cells, either by sAC knockdown, by pharmacological inhibition or by withdrawal of bicarbonate, a natural sAC activator, compromised cell viability and recovery of cytosolic Ca2+ homeostasis during reperfusion. Contrariwise, overexpression of mitochondria-targeted sAC in H9C2 cells suppressed reperfusion-induced cell death. Analyzing cAMP concentration in mitochondrial matrix we found that inhibition of PDE2, a predominant mitochondria-localized PDE isoform in mammals, during reperfusion significantly increased cAMP level in mitochondrial matrix, but not in cytosol. Accordingly, PDE2 inhibition attenuated reperfusion-induced cardiomyocyte death and improved recovery of the cytosolic Ca2+ homeostasis. CONCLUSION: sAC plays an essential role in supporting cardiomyocytes viability during reperfusion. Elevation of mitochondrial cAMP pool either by sAC overexpression or by PDE2 inhibition beneficially affects cardiomyocyte survival during reperfusion.

Mortality among very low birth weight infants after hospital discharge in a low resource setting.

BACKGROUND: Early discharge of very low birth weight infant (VLBW) in low resource settings is inevitable but to minimize mortality of these infants after discharge we need to identify the death attributes. METHOD: A prospective cohort was conducted among 190 VLBW infants discharged from Mulago Special Care Baby Unit (SCBU) with discharge weight of < 1500 g over an 8 months period. These infants were followed up with the aims of determining the proportion dead 3 months after discharge, identifying factors associated and possible causes of death. Relevant data were captured, transferred in to STATA and imported to SPSS 12.0.1 for analysis. To determine factors associated with mortality bi-variable and multivariable regressions were conducted. A p-value of < 0.05 was considered significant and 95% confidence interval was used. RESULTS: Of the enrolled infants 164 (86.3%) completed follow up. The median gestational age of study participants was 32 weeks (range 26-35 weeks), the mean discharge weight was 1119 g (range 760-1470 g), and 59.8% were small for gestational age (SGA). During follow up 32 (19.5%) infants died. Infants discharged with weight of < 1200 g accounted for 81.2% of the deaths. Majority of the deaths (68.7%) occurred in the first month after discharge. Factors independently associated with mortality were discharge weight < 1000 g (OR 3.10, p 0.015) and not being SGA (OR 3.54, p 0.019). The main causes of death were presumed sepsis 50.0% and suspected cot death (25.0%). CONCLUSION: Mortality after hospital discharge among VLBW infants is high. Discharge at weight < 1200 g may not be a safe practice. Measures to prevent sepsis and suspected cot death should be addressed prior to considering early discharge of these infants.

Adverse Effects on ß-Adrenergic Receptor Coupling: Ischemic Postconditioning Failed to Preserve Long-Term Cardiac Function.

BACKGROUND: Ischemic preconditioning (IPC) and ischemic postconditioning (IPoC) are currently among the most efficient strategies protecting the heart against ischemia/reperfusion injury. However, the effect of IPC and IPoC on functional recovery following ischemia/reperfusion is less clear, particularly with regard to the specific receptor-mediated signaling of the postischemic heart. The current article examines the effect of IPC or IPoC on the regulation and coupling of ß-adrenergic receptors and their effects on postischemic left ventricular function. METHODS AND RESULTS: The ß-adrenergic signal transduction was analyzed in 3-month-old Wistar rats for each of the intervention strategies (Sham, ischemia/reperfusion, IPC, IPoC) immediately and 7 days after myocardial infarction. Directly after the infarction a cardioprotective potential was demonstrated for both IPC and IPoC: the infarct size was reduced, apoptosis and production of reactive oxygen species were lowered, and the myocardial tissue was preserved. Seven days after myocardial ischemia, only IPC hearts showed significant functional improvement. Along with a deterioration in fractional shortening, IPoC hearts no longer responded adequately to ß-adrenergic stimulation. The stabilization of ß-adrenergic receptor kinase-2 via increased phosphorylation of Mdm2 (an E3-ubiquitin ligase) was responsible for desensitization of ß-adrenergic receptors and identified as a characteristic specific to IPoC hearts. CONCLUSIONS: Immediately after myocardial infarction, rapid and transient activation of ß-adrenergic receptor kinase-2 may be an appropriate means to protect the injured heart from excessive stress. In the long term, however, induction and stabilization of ß-adrenergic receptor kinase-2, with the resultant loss of positive inotropic function, leads to the functional picture of heart failure.

Is facility based neonatal care in low resource setting keeping pace? A glance at Uganda's National Referral Hospital.

OBJECTIVES: To identify reasons for neonatal admission and death with the aim of determining areas needing improvement. METHOD: A retrospective chart review was conducted on records for neonates admitted to Mulago National Referral Hospital Special Care Baby Unit (SCBU) from 1(st) November 2013 to 31(st) January 2014. Final diagnosis was generated after analyzing sequence of clinical course by 2 paediatricians. RESULTS: A total of 1192 neonates were admitted. Majority 83.3% were in-born. Main reasons for admissions were prematurity (37.7%) and low APGAR (27.9%).Overall mortality was 22.1% (Out-born 33.6%; in born 19.8%). Half (52%) of these deaths occurred in the first 24 hours of admission. Major contributors to mortality were prematurity with hypothermia and respiratory distress (33.7%) followed by birth asphyxia with HIE grade III (24.6%) and presumed sepsis (8.7%). Majority of stable at risk neonates 318/330 (i.e. low APGAR or prematurity without comorbidity) survived. Factors independently associated with death included gestational age <30 weeks (p 0.002), birth weight <1500g (p 0.007) and a 5 minute APGAR score of < 7 (p 0.001). Neither place of birth nor delayed and after hour admissions were independently associated with mortality. CONCLUSION AND RECOMMENDATIONS: Mortality rate in SCBU is high. Prematurity and its complications were major contributors to mortality. The management of hypothermia and respiratory distress needs scaling up. A step down unit for monitoring stable at risk neonates is needed in order to decongest SCBU.

Prevalence and immediate outcome of candida colonized preterm neonates admitted to Special Care Unit of Mulago Hospital, Kampala Uganda.

BACKGROUND: Candida species is the third commonest cause of sepsis among neonates. Colonization by Candida is a predictor for candidemia among preterm neonates. OBJECTIVES: To determine prevalence of early Candida colonization and early outcome among colonized preterm neonates admitted to Mulago hospital Special Care Unit. METHODS: A prospective observational cohort was conducted between December 2008 and April 2009. Preterm neonates aged >72 hours and less than one week were screened for Candida colonization of the groin, oral pharynx and rectum using CHROMagar. Colonized neonates were followed up for 14 days. Blood cultures were done for those with signs of septicaemia. The Fisher's exact tests and logistic regression were conducted for factors associated with colonization and mortality among colonized neonates. P values of < 0.05 were considered significant and confidence interval of 95% was used. RESULTS: Candida colonization occurred in 50/213 (23.5%) neonates. Gestational age ≤ 30 weeks was the only factor independently associated with colonization (p = 0.005). Of the colonized 14/46 (30.4%) died and 13/46 (28.3%) developed mucocutaneous candidiasis. No candidemia was identified. Multiple site colonization was independently associated with mortality (p=0.035). CONCLUSION: The consequence of high colonization observed in this study needs to be further elucidated in Uganda.

Mechanisms by which calcium receptor stimulation modifies electromechanical coupling in isolated ventricular cardiomyocytes.

The calcium-sensing receptor (CaR) is widely expressed throughout the entire cardiovascular system and is capable of activating signaling pathways in different cells. Alongside calcium, the CaR also responds to physiological polycations such as putrescine underlining a participation in physiological and pathophysiological processes. Here, we aimed to determine mechanisms as to how CaR activation affects the contractile responsiveness of ventricular cardiomyocytes under basal and stimulated conditions. For that purpose, cardiac myocytes from 3-month-old male Wistar rats were isolated, and the acute effects of an antagonist (NPS2390), agonists (putrescine and gadolinium), or of downregulation of the CaR by siRNA on cell shortening were recorded in a cell-edge-detection system. In addition, experiments were performed on muscle stripes and Langendorff preparations. Mechanistic insights were taken from calcium transients of beating fura-2 AM-loaded cardiomyocytes and western blots. Isolated ventricular cardiomyocytes constitutively express CaR. The expression in the atria is less pronounced. Acute inhibition of CaR reduced basal cell shortening of ventricular myocytes at nearly physiological levels of extracellular calcium. Inhibition of CaR strongly reduced contractility of ventricular muscle stripes but not of atria. Activation of CaR by putrescine and gadolinium influences the contractile responsiveness of isolated cardiomyocytes. Increased calcium mobilization from the sarcoplasmic reticulum via an IP3-dependent mechanism was responsible for amplified systolic calcium transients and a subsequent improvement in cell shortening. Alongside with these effects, activation of CaR increased relaxation velocity of the cells. In conclusion, ventricular CaR expression affects contractile parameters of ventricular heart muscle cells and modifies electromechanical coupling of cardiomyocytes.

Regulation of monocyte/macrophage function by factor VII activating protease (FSAP).

OBJECTIVE: Factor VII activating protease (FSAP) is a novel regulator of vascular inflammation and hemostasis. However, the molecular mechanism by which circulating FSAP influences inflammatory events and progression of atherosclerosis is not yet entirely understood. Here we have investigated the influence of FSAP on monocyte/macrophage functions. METHODS: We stimulated human monocyte-derived macrophages with FSAP and analyzed their cellular responses. RESULTS: FSAP induced IκB-dependent NF-κB activation in a time- and concentration-dependent fashion. FSAP also activated the phosphorylation and proteolytic degradation of the inhibitor protein IκBα. The phosphorylation of the p65 subunit of NF-κB was induced by FSAP, which is known to contribute to the enhancement of DNA-binding activity of NF-κB. Concomitantly, FSAP up-regulated the expression of pro-inflammatory cytokines, matrix metalloproteinases, cell adhesion molecules and tissue factor. In the presence of FSAP there was increased monocytes adhesion and transendothelial migration in a beta2 integrin dependent manner. CONCLUSIONS: Our findings suggest that FSAP activates the NF-κB pathway and the associated downstream pro-inflammatory factors in monocytic cells. This adds to a spectrum of FSAP effects on the vascular system that may explain its association with cardiovascular diseases.

Mechanisms involved in postconditioning protection of cardiomyocytes against acute reperfusion injury.

Experimental and clinical studies demonstrated that postconditioning confers protection against myocardial ischemia/reperfusion injury. However the underlying cellular mechanisms responsible for the beneficial effect of postconditioning are still poorly understood. The aim of the present study was to examine the role of cytosolic and mitochondrial Ca(2+)-handling. For this purpose adult rat cardiomyocytes were subjected to simulated in vitro ischemia (glucose-free hypoxia at pH6.4) followed by simulated reperfusion with a normoxic buffer (pH7.4; 2.5 mmol/L glucose). Postconditioning, i.e., 2 repetitive cycles of normoxic (5s) and hypoxic (2.5 min) superfusion, was applied during the first 5 min of reoxygenation. Mitochondrial membrane potential (ΔΨm), cytosolic and mitochondrial Ca(2+) concentrations, cytosolic pH and necrosis were analysed applying JC-1, fura-2, fura-2/manganese, BCECF and propidium iodide, respectively. Mitochondrial permeability transition pore (MPTP) opening was detected by calcein release. Hypoxic treatment led to a reduction of ΔΨm, an increase in cytosolic and mitochondrial Ca(2+) concentration, and acidification of cardiomyocytes. During the first minutes of reoxygenation, ΔΨm transiently recovered, but irreversibly collapsed after 7 min of reoxygenation, which was accompanied by MPTP opening. Simultaneously, mitochondrial Ca(2+) increased during reperfusion and cardiomyocytes developed spontaneous cytosolic Ca(2+) oscillations and severe contracture followed by necrosis after 25 min of reoxygenation. In postconditioned cells, the collapse in ΔΨm as well as the leak of calcein, the increase in mitochondrial Ca(2+), cytosolic Ca(2+) oscillations, contracture and necrosis were significantly reduced. Furthermore postconditioning delayed cardiomyocyte pH recovery. Postconditioning by hypoxia/reoxygenation was as protective as treatment with cyclosporine A. Combining cyclosporine A and postconditioning had no additive effect. The data of the present study demonstrate that postconditioning by hypoxia/reoxygenation prevents reperfusion injury by limiting mitochondrial Ca(2+) load and thus opening of the MPTP in isolated cardiomyocytes. These effects seem to be supported by postconditioning-induced delay in pH recovery and suppression of Ca(2+) oscillations.

The mechanisms of energy crisis in human astrocytes after subarachnoid hemorrhage.

BACKGROUND: Calcium (Ca2+) is a cofactor of multiple cellular processes. The mechanisms that lead to elevated cytosolic Ca2+ concentration are unclear. OBJECTIVE: To illuminate how bloody cerebrospinal fluid (bCSF) from patients with intraventricular hemorrhage causes cell death of cultured human astrocytes. METHODS: Cultured astrocytes were incubated with bCSF. In control experiments, native CSF was used. Cytosolic Ca2+ concentration was measured by fura-2 fluorescence. Apoptosis and necrosis were evaluated by staining with Hoechst-3342 and propidium iodide. RESULTS: Incubation of astrocytes with bCSF provoked a steep Ca2+ concentration peak that was followed by a slow Ca2+ rise during the observation period of 50 minutes. Necrosis, but not apoptosis, was induced. Blockade of ATP-sensitive P2 receptors with suramin inhibited the bCSF-induced initial Ca2+ peak and necrosis. Blockade of P1 receptors with 8-phenyltheophylline or of N-methyl-D-aspartate receptors with D(-)-2-amino-5-phosphopentanoic acid had no significant effect. Preincubation with xestospongin D, a blocker of inositol 1,4,5-trisphosphate receptors, prevented the initial Ca2+ rise and reduced the rate of necrosis. Preemptying of the endoplasmic reticulum with thapsigargin protected astrocytes from the bCSF-induced Ca2+ peak. Inhibition of mitochondrial permeability transition pores opening with cyclosporin A reduced the rate of astrocytic necrosis significantly, although it did not influence the initial Ca peak. CONCLUSION: bCSF elicits a steep, transient Ca rise when administered to human astrocytes by activation of ATP-sensitive P2 receptors and subsequent inositol 1,4,5-trisphosphate-dependent Ca release from endoplasmic reticulum. This massive Ca overload leads to subsequent mitochondrial permeability transition pores opening and necrosis of the cells.

Factor seven activating protease (FSAP) expression in human placenta and its role in trophoblast migration.

OBJECTIVES: Factor seven activating protease (FSAP) is a plasma serine protease known to play a critical role in hemostasis and remodeling processes: FSAP levels increase markedly during normal pregnancy. In order to define the role of FSAP in vascular pathophysiology in pregnant women and particularly in the placenta, we performed this study (i) to evaluate the FSAP expression in human placenta and (ii) to identify the role of FSAP in human trophoblast migration. STUDY DESIGN: FSAP expression in placental tissues was analyzed by using immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). To determine whether FSAP plays any role in trophoblast migration, we used human trophoblast cells in transwell migration assays. RESULTS: Immunohistochemistry showed that FSAP protein was expressed by syncytiotrophoblast and in the cytoplasma of invasive extravillous trophoblasts (EVT) within the maternal decidua (DC) in implantation sites of human first trimester placenta. Furthermore, FSAP mRNA and protein decreased with gestational age (p<0.05, 1st vs 3rd trimester). FSAP (10µg/ml) had a significant stimulatory effect on the migration of human trophoblast cells. This effect was abolished by addition of aprotinin to block the enzymatic activity of FSAP. CONCLUSIONS: The high expression level of FSAP in the placenta supports a relevant role of this protease in trophoblast migration and vascular remodeling, identifies a new concept of coagulation/fibrinolysis at the feto-maternal interface and may be essential for the maintenance of pregnancy.

Nicotine modulation of factor VII activating protease (FSAP) expression in human monocytes.

AIM: Factor VII activating protease (FSAP) is a plasma serine protease involved in hemostasis and remodeling processes. Increased levels of circulating FSAP during pregnancy and in women using oral contraceptives (OCs) indicate that the hormonal status critically influences FSAP expression. In this respect, the aim of this study was to quantify nicotine modulation of FSAP expression in human monocytes/macrophages isolated from healthy female smokers and non-smokers, and from women who use OCs and smoke. METHODS: FSAP concentration and activity were measured in plasma samples obtained from healthy non-pregnant, pre-menopausal, non-smoking women who did not use OCs (n=69), non-pregnant, pre-menopausal women who currently smoke and use OCs (n=43), and women who are only smokers (n=40) or currently use OCs (n=48). Expressions of FSAP mRNA and protein in monocytes isolated from healthy non-pregnant female or healthy male donors were analyzed. RESULTS: Strongest circulating FSAP concentration and activity occurred in women with combined smoking and use of OCs compared to the control group. Enhanced FSAP levels were also observed in smoking women when compared to non-smokers. Ex vivo experiments demonstrated enhanced FSAP expression in monocytes isolated from women using OCs and currently smoking. Nicotine enhanced FSAP mRNA and protein levels in monocytes. CONCLUSIONS: Monocytes from healthy female smokers show a constitutively enhanced FSAP expression and this effect could be replicated in vitro by stimulating monocytes with nicotine. The upregulation of FSAP due to nicotine and OC usage may be linked to a higher incidence of arteriothromboembolic diseases related to their usage.

Effects of cerivastatin on adrenergic pathways, hypertrophic growth and TGFbeta expression in adult ventricular cardiomyocytes.

The effects of statin treatment in the setting of heart failure have already been shown. Nevertheless, there is little knowledge about its influence on adrenergic pathways in cardiomyocytes. Therefore, this study investigated the impact of cerivastatin on adrenoceptor-mediated signalling pathways in isolated adult ventricular cardiomyocytes. It focused on two endpoints: hypertrophic growth and TGFbeta expression. Cultured cardiomyocytes were used to study rac activation (analysed by its translocation into the membrane fraction), ROS formation (H(2)DCF fluorescence) and hypertrophic growth ((14)C-phenylalanine incorporation). Alpha- and beta-adrenoceptor stimulation showed significant differences regarding rac activation, ROS formation, and p38 MAP kinase activation. Both alpha- and beta-adrenoceptor stimulation induced TGFbeta expression. Upon activation of alpha-adrenergic signalling - although ROS formation was not influenced by cerivastatin - TGFbeta expression decreased. Following beta stimulation, TGFbeta expression as well as rac and p38 MAP kinase activation were reduced after pre-treatment with cerivastatin. Statin treatment did not show any influence on hypertrophic growth. In summary, this study clearly demonstrates the ability of adrenoceptor stimulation to increase TGFbeta expression. One component of the beneficial effects of statin therapy on heart failure might therefore be due to a dominant reduction and inhibition of TGFbeta, which is involved in many pathophysiological processes in cardiomyocytes.

Opposing effects of ATP and adenosine on barrier function of rat coronary microvasculature.

ATP can differentially affect the micro- and macrovascular endothelial barrier. It has been shown that it can both increase and/or decrease macromolecule permeability of microvascular endothelial cells and microvessels, in vivo. We hypothesised that the barrier stabilising effect is mediated by ATP itself via P2 receptors, while barrier-disrupting effect is mediated by its metabolite adenosine via adenosine receptors. The effects of ATP, ADP, AMP and adenosine on barrier function were studied in cultured rat coronary microvascular endothelial monolayers (RCEC) in vitro, as well as in rat mesentery vessels, and in rat hearts in vivo. ATP and ADP showed a biphasic effect on permeability of RCEC monolayers with a reduction followed by a later increase in albumin permeability. The permeability decreasing effect of ATP was enhanced by ecto-nucleotidase inhibitor ARL67156 while permeability increasing effect was enhanced by apyrase, an extracellular ecto-nucleotidase. Moreover, the permeability increasing effect was abrogated by adenosine receptor antagonists, 8-phenyltheophylline (8-PT) and DMPX. Adenosine and adenosine receptor agonists 5'-(N-ethylcarboxamido)-adenosine (NECA), CGS21680, and R-PIA enhanced albumin permeability which was antagonised by 8-PT, A(1), and A(2) but not by A(3) receptor antagonists. Likewise, immunofluorescence microscopy of VE-cadherin and actin showed that NECA induces a disturbance of intercellular junctions. Pre-incubation of ATP antagonised the effects of NECA on permeability, actin cytoskeleton and intercellular junctions. Similar effects of the applied substances were observed in rat mesentery artery by determining the vascular leakage using intravital microscopy as well as in rat hearts by assessing myocardial water contents in vivo. In conclusion, the study demonstrates that in RCEC, ATP, ADP, and its metabolite adenosine play opposing roles on endothelial barrier function.