Temporary threshold shift after noise exposure in hypobaric hypoxia at high altitude: results of the ADEMED expedition 2011.

OBJECTIVES: To evaluate whether there is an increased risk for noise-induced hearing loss at high altitude rsp. in hypobaric hypoxia. METHODS: Thirteen volunteers got standard audiometry at 125, 250, 500, 750, 1000, 1500, 2000, 3000, 4000, 6000, and 8000 Hz before and after 10 min of white noise at 90 dB. The system was calibrated for the respective altitude. Measurements were performed at Kathmandu (1400 m) and at Gorak Shep (5300 m) (Solo Khumbu/Nepal) after 10 days of acclimatization while on trek. Temporary threshold shift (TTS) was analyzed by descriptive statistics and by factor analysis. RESULTS: TTS is significantly more pronounced at high altitudes. Acclimatization does not provide any protection of the inner ear, although it increases arterial oxygen saturation. CONCLUSION: The thresholds beyond which noise protection is recommended (> 80 dB) or necessary (> 85 dB) are not sufficient at high altitudes. We suggest providing protective devices above an altitude of 1500 m ("ear threshold altitude") when noise level is higher than 75 dB and using them definitively above 80 dB. This takes the individual reaction on hypobaric hypoxia at high altitude into account.

A prospective outcome study observing patients with severe traumatic brain injury over 10-15 years.

BACKGROUND: Severe traumatic brain injury (sTBI) can be divided into primary and secondary injuries. Intensive care protocols focus on preventing secondary injuries. This prospective cohort study was initiated to investigate outcome, including mortality, in patients treated according to the Lund Concept after a sTBI covering 10-15 years post-trauma. METHODS: Patients were included during 2000-2004 when admitted to the neurointensive care unit, Sahlgrenska University Hospital. Inclusion criteria were: Glasgow coma scale score of ≤8, need for artificial ventilation and intracranial monitoring. Glasgow Outcome Scale (GOS) was used to evaluate outcome both at 1-year and 10-15 years post-trauma. RESULTS: Ninety-five patients, (27 female and 68 male), were initially included. Both improvement and deterioration were noted between 1- and 10-15 years post-injury. Mortality rate (34/95) was higher in the studied population vs. a matched Swedish population, (Standard mortality rate (SMR) 9.5; P < 0.0001). When dividing the cohort into Good (GOS 4-5) and Poor (GOS 2-3) outcome at 1-year, only patients with Poor outcome had a higher mortality rate than the matched population (SMR 7.3; P < 0.0001). Further, good outcome (high GOS) at 1-year was associated with high GOS 10-15 years post-trauma (P < 0.0001). Finally, a majority of patients demonstrated symptoms of mental fatigue. CONCLUSION: This indicates that patients with severe traumatic brain injury with Good outcome at 1-year have similar survival probability as a matched Swedish population and that high Glasgow outcome scale at 1-year is related to good long-term outcome. Our results further emphasise the advantage of the Lund concept.

Mitochondria-targeted dodecyltriphenylphosphonium (C12TPP) combats high-fat-diet-induced obesity in mice.

BACKGROUND: A membrane-penetrating cation, dodecyltriphenylphosphonium (C12TPP), facilitates the recycling of fatty acids in the artificial lipid membrane and mitochondria. C12TPP can dissipate mitochondrial membrane potential and may affect total energy expenditure and body weight in animals and humans. METHODS: We investigated the metabolic effects of C12TPP in isolated brown-fat mitochondria, brown adipocyte cultures and mice in vivo. Experimental approaches included the measurement of oxygen consumption, carbon dioxide production, western blotting, magnetic resonance imaging and bomb calorimetry. RESULTS: In mice, C12TPP (50 µmol per (day•kg body weight)) in the drinking water significantly reduced body weight (12%, P<0.001) and body fat mass (24%, P<0.001) during the first 7 days of treatment. C12TPP did not affect water palatability and intake or the energy and lipid content in feces. The addition of C12TPP to isolated brown-fat mitochondria resulted in increased oxygen consumption. Three hours of pretreatment with C12TPP also increased oligomycin-insensitive oxygen consumption in brown adipocyte cultures (P<0.01). The effects of C12TPP on mitochondria, cells and mice were independent of uncoupling protein 1 (UCP1). However, C12TPP treatment increased the mitochondrial protein levels in the brown adipose tissue of both wild-type and UCP1-knockout mice. Pair-feeding revealed that one-third of the body weight loss in C12TPP-treated mice was due to reduced food intake. C12TPP treatment elevated the resting metabolic rate (RMR) by up to 18% (P<0.05) compared with pair-fed animals. C12TPP reduced the respiratory exchange ratio, indicating enhanced fatty acid oxidation in mice. CONCLUSIONS: C12TPP combats diet-induced obesity by reducing food intake, increasing the RMR and enhancing fatty acid oxidation.

Prospective Assessment of Radiation in Pediatric Urology: The Pediatric Urology Radiation Safety Evaluation Study.

PURPOSE: Pediatric tissues are exquisitely sensitive to ionizing radiation from diagnostic studies and therapies involving fluoroscopy. We prospectively monitored radiation exposure in our pediatric urology patients during fluoroscopy guided operative procedures with single point dosimeters to quantify radiation dose. MATERIALS AND METHODS: Children undergoing fluoroscopy guided urological procedures were prospectively enrolled in the study from 2013 to 2015. Single point dosimeters were affixed to skin overlying the procedural site for the durations of the procedures to record dosimetry data. Patient demographics, procedural variables and fluoroscopic settings were recorded. RESULTS: A total of 78 patients underwent 96 procedures, including retrograde pyelography, ureteral stent insertion, ureteroscopy and percutaneous nephrolithotomy. Median patient age was 12 years (range 0.3 to 17) and median body mass index percentile for age was 70.7 (1.0 to 99.1). Median skin entrance radiation dose for all procedures performed was 0.56 mGy. Median dosages associated with the 29 diagnostic procedures and 49 definitive interventions were 0.6 mGy (mean 0.8, range 0.1 to 2.2) and 0.7 mGy (1.1, 0.0 to 5.5), respectively. The dose associated with the 18 procedures of temporization was significantly higher by comparison (median 1.0 mGy, mean 2.6, range 0.1 to 10.7, p = 0.02). CONCLUSIONS: Pediatric radiation exposure is not insignificant during urological procedures. Further multi-institutional work would provide context for our findings. Protocols to optimize fluoroscopic settings and minimize patient exposure, and guidelines for radiation based imaging should have a key role in all pediatric radiation safety initiatives.

Apolipoprotein E polymorphism in aneurysmal subarachnoid haemorrhage in West Sweden.

BACKGROUND AND PURPOSE: Aneurysmal subarachnoid haemorrhage (aSAH) is associated with high morbidity and mortality despite novel treatments. Genetic variability may explain outcome differences. Apolipoprotein E (ApoE) is a glycoprotein with a major role in brain lipoprotein metabolism. It has three isoforms encoded by distinct alleles: APOEε2, APOEε3 and APOEε4. The APOEε4 allele is associated with Alzheimer's disease and worse outcome after traumatic brain injury and ischaemic stroke. This prospective blinded study explored the influence of the APOEε4 polymorphism on the risk of aSAH, risk of cerebral vasospasm (CVS) and 1-year neurological outcome. METHODS: The APOΕε4 polymorphism was analysed in 147 patients with aSAH. Allele and genotype frequencies were compared to those found in a gender- and area-matched control group of healthy individuals (n = 211). Early CVS was identified and treated according to neurointensive care unit (NICU) guidelines. Neurological deficit(s) at admittance and at 1-year follow-up visit was recorded. Neurological outcome was assessed by the National Institute of Health Stroke Scale, Barthel Index and the Extended Glasgow Outcome Scale. RESULTS: APOEε4 and non-APOEε4 allele frequencies were similar in aSAH patients and healthy individuals. The presence of APOEε4 was not associated with the development of early CVS. We could not find an influence of the APOE polymorphism on 1-year neurological outcome between groups. Subgroup analyses of patients treated with surgical clipping vs endovascular coiling did not reveal any associations. CONCLUSIONS: The APOEε4 polymorphism has no major influence on risk of aSAH, the occurrence of CVS or long-term neurological outcome after aSAH.

Tracking of radiation exposure in pediatric stone patients: The time is now.

BACKGROUND: Despite the increasing incidence of pediatric nephrolithiasis, there is little data quantifying the radiation exposure associated with treatment of this disease. In this study, pediatric patients with nephrolithiasis who were managed at a single institution were identified, and the average fluoroscopy time and estimated radiation exposure associated with their procedures were reported. METHODS: Stone procedures performed on pediatric patients between 2005 and 2012 were retrospectively identified. Procedures were classified as primary ureteroscopy (URS), stent placement prior to ureteroscopy (SURS), percutaneous nephrolithotomy (PCNL), and bilateral ureteroscopy (BLURS). Patient demographic information, stone size, stone location, number of radiographic images, and fluoroscopy times were analyzed. RESULTS: A total of 152 stone procedures were included in the final analysis (92 URS, 38 SURS, eight BLURS and 14 PCNL). Mean patient age at time of stone treatment was 15.94 ± 4.1 years. Median fluoroscopy times were 1.6 (IQR 0.8-2.4), 2.1 (IQR 1.6-3.0), 2.5 (IQR 2.0-2.9), and 11.7 (IQR 5.0-18.5) minutes for URS, SURS, BLURS and PCNL, respectively. There was a moderate correlation between stone size and fluoroscopy time (r = 0.33). When compared with ureteroscopic procedures, PCNL was associated with a significantly higher fluoroscopy time (11.7 vs 2.1 min, P < 0.001). The estimated median effective dose was 3 mSv for ureteroscopic procedures and 16.8 mSv for PCNL. In addition to radiation exposure during treatment, patients in this cohort were exposed to an average of one (IQR1-3) CT scan and three (IQR 1-8) abdominal X-rays. No new malignancies were identified during the limited follow-up period. CONCLUSIONS: Radiation exposure during treatment of pediatric stone disease is not trivial, and is significantly greater when PCNL is performed. Given the recommended maximum effective dose of 50 mSv in any one year, urologists should closely monitor the amount of fluoroscopy used, and consider the potential for radiation exposure when choosing the operative approach. Prospective studies are currently underway to elucidate precise dose measurements and localize sites of radiation exposure in children during stone treatment.

In-hospital C-reactive protein predicts outcome after aneurysmal subarachnoid haemorrhage treated by endovascular coiling.

BACKGROUND: This study aimed to examine prospectively whether the inflammatory marker C-reactive protein (CRP) increases in patients with aneurysmal subarachnoid haemorrhage (aSAH) treated by endovascular coiling and investigate whether CRP could be used as prognostic factor for long-term neurological outcome. METHODS: This single-hospital study comprised 98 consecutive patients with confirmed aSAH treated by endovascular coiling. Admission status was classified according to the World Federation of Neurosurgical Societies (WFNS) Scale and initial cerebral computed tomography according to Fisher scale. CRP was analysed on days 0, 1, 2, 3, 4, 6 and 8 after the initial bleed. A neurological follow up was performed 1 year later according to the Extended Glasgow Outcome Scale (GOSE) for overall outcome and National Institute of Health Stroke Scale (NIHSS) for focal deficit. RESULTS: CRP values increased from normal to peak at 53 mg/l at day 3-4 and then declined, without normalising, at day 8. Patients with a higher increase in CRP had a poorer neurological outcome after 1 year. CRP during the first week had a stronger correlation to outcome (r = 0.417) and NIHSS (r = 0.449) than initial clinical status (WFNS; r = 0.280 and 0.274) and radiology (Fisher scale; r = 0.137 and 0.158). CRP increase indicated a risk of poor outcome (GOSE) (P < 0.001) and permanent loss of neurological function (NIHSS) (P < 0.001). Logistic regression analysis suggested that elevated CRP already on day 2 is an independent prognostic marker for outcome. CONCLUSION: Early CRP values can perhaps be used as a prognostic factor for long-term neurological outcome prediction after endovascular treatment of aSAH.

Neutrophilic myeloid-derived suppressor cells in cord blood modulate innate and adaptive immune responses.

Neonates show an impaired anti-microbial host defence, but the underlying immune mechanisms are not understood fully. Myeloid-derived suppressor cells (MDSCs) represent an innate immune cell subset characterized by their capacity to suppress T cell immunity. In this study we demonstrate that a distinct MDSC subset with a neutrophilic/granulocytic phenotype (Gr-MDSCs) is highly increased in cord blood compared to peripheral blood of children and adults. Functionally, cord blood isolated Gr-MDSCs suppressed T cell proliferation efficiently as well as T helper type 1 (Th1), Th2 and Th17 cytokine secretion. Beyond T cells, cord blood Gr-MDSCs controlled natural killer (NK) cell cytotoxicity in a cell contact-dependent manner. These studies establish neutrophilic Gr-MDSCs as a novel immunosuppressive cell subset that controls innate (NK) and adaptive (T cell) immune responses in neonates. Increased MDSC activity in cord blood might serve as key fetomaternal immunosuppressive mechanism impairing neonatal host defence. Gr-MDSCs in cord blood might therefore represent a therapeutic target in neonatal infections.

Skeletal muscle uncoupling-induced longevity in mice is linked to increased substrate metabolism and induction of the endogenous antioxidant defense system.

Ectopic expression of uncoupling protein 1 (UCP1) in skeletal muscle (SM) mitochondria increases lifespan considerably in high-fat diet-fed UCP1 Tg mice compared with wild types (WT). To clarify the underlying mechanisms, we investigated substrate metabolism as well as oxidative stress damage and antioxidant defense in SM of low-fat- and high-fat-fed mice. Tg mice showed an increased protein expression of phosphorylated AMP-activated protein kinase, markers of lipid turnover (p-ACC, FAT/CD36), and an increased SM ex vivo fatty acid oxidation. Surprisingly, UCP1 Tg mice showed elevated lipid peroxidative protein modifications with no changes in glycoxidation or direct protein oxidation. This was paralleled by an induction of catalase and superoxide dismutase activity, an increased redox signaling (MAPK signaling pathway), and increased expression of stress-protective heat shock protein 25. We conclude that increased skeletal muscle mitochondrial uncoupling in vivo does not reduce the oxidative stress status in the muscle cell. Moreover, it increases lipid metabolism and reactive lipid-derived carbonyls. This stress induction in turn increases the endogenous antioxidant defense system and redox signaling. Altogether, our data argue for an adaptive role of reactive species as essential signaling molecules for health and longevity.

[Mediastinal fibrosis and mirtazapin]. / Fibrose médiastinale et mirtazapine.

We report a 61-year-old woman who developed a superior vena cava syndrome due to mediastinal fibrosis. This mediastinal fibrosis resolved after the discontinuation of a chronic treatment by mirtazapin that the patient was receiving for the previous six years, suggesting a role of this treatment in the genesis of the mediastinal fibrosis.

An improved method to culture Staphylococcus aureus from bovine milk.

Staphylococcus aureus is an important udder pathogen often associated with subclinical mastitis in dairy cows. Identification of Staph. aureus-positive udder quarters and cows is an important part of control programs to reduce spread of Staph. aureus within and between dairy herds. Therefore, accurate and easy-to-perform culturing methods of Staph. aureus in milk are needed. In the present study, 8 methods for isolation of Staph. aureus in bovine milk samples were investigated. The methods involved different culturing volumes, enrichment, incubation, and freezing processes as well as sedimentation and use of the Mastistrip cassette (SVA, Uppsala, Sweden). Three different sets of milk samples were collected, and 6, 5, and 4 methods were used in each subset of samples. Our results indicate an increased probability of detecting Staph. aureus in milk samples when a simple incubation step (37 degrees C for 18 h) without additives was included before culturing. Using this incubation method, the number of Staph. aureus-positive udder quarters and cows increased by 50 and 29%, respectively, compared with using the standard method of direct culturing of 10 microL of milk. The improved method may be especially useful for detection of low concentrations of Staph. aureus in milk; for example, when screening herds for Staph. aureus.

Microbial aetiology of acute clinical mastitis and agent-specific risk factors.

A nation wide study on the microbial aetiology of cases of acute clinical mastitis in Swedish dairy cows was conducted with the aim to investigate changes in the microbial panorama compared to a previous study performed 1994-1995. Another aim was to investigate some agent-specific environmental and individual risk factors. Milk samples were collected from 987 udder quarter cases from 829 cows during six 2-month periods from May 2002 to April 2003, and data on risk factors and demography were collected at sampling by means of a questionnaire. In total, 1056 bacteriological diagnoses were made. The most frequently isolated bacterial species was Staphylococcus aureus constituting 21.3% of the diagnoses, followed by Escherichia coli (15.9%), Streptococcus dysgalactiae (15.6%), Streptococcus uberis (11.1%), coagulase-negative staphylococci (6.2%), Arcanobacterium pyogenes (6.1%) and Klebsiella spp. (4.2%). Samples with no growth or contamination constituted 10.6% and 4.5% of the diagnoses, respectively. A major shift in the panorama of udder pathogens was not observed compared to the survey in 1994-1995. Isolation of Klebsiella spp. was strongly associated with the use of sawdust as bedding material. On the other hand, using sawdust as bedding reduced the risk of isolating S. uberis relative to using straw or peat. The risk of isolating E. coli increased with increasing milk yield and was higher in loose housing systems than in tie stalls. Isolation of S. aureus was associated with tie stalls, and A. pyogenes with low yielding cows and teat lesions. S. dysgalactiae infections were also associated with teat lesions.

Apolipoprotein E polymorphism and gender difference in outcome after severe traumatic brain injury.

BACKGROUND: Traumatic brain injury (TBI) is one of the most common causes of death and dismal outcome among children and young adults. The morbidity and mortality differ but more aggressive monitoring and more designated neuro intensive care units have improved the results. Studies have demonstrated a connection between apolipoprotein E (APOE) genotype and outcome after TBI, but few are prospective and none is from northern Europe. APOE has three alleles: epsilon2, epsilon3 and epsilon4. METHODS: A total of 96 patients with Glasgow coma score (GCS) < or =8 were prospectively and consecutively included. APOE genotypes were all analyzed at the same laboratory from blood samples by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: All patients were assessed at 1 year with Glasgow outcome scale extended (GOSE), National Institute of Health Stroke Scale (NIHSS) and the Barthel daily living index. The genotype was available in all patients. Twenty-six patients expressed APOE epsilon4 while 70 patients did not. Outcome demonstrated that patients with APOE epsilon4 had worse outcome vs. those lacking this allele. When subdividing patients into gender, males with APOE epsilon4 did worse, a difference not detected among female patients. CONCLUSIONS: APOE epsilon4 correlated to worse outcome in TBI patients. We also found that males with APOE epsilon4 had poor outcome while females did not. Thus, the results indicate that genetic polymorphism may influence outcome after TBI.

Serum levels of S100B, S100A1B and S100BB are all related to outcome after severe traumatic brain injury.

OBJECTIVES: S100B is an established marker of brain damage. Used in the context as a biochemical marker, S100B denotes a measurement of all S100 proteins, including at least one S100B monomer, i.e. the sum of the two dimers S100A1B and S100BB. Almost all published studies are based on this "sum concentration". However, the brain specificity of S100B has been questioned and increased serum levels have also been reported after trauma without head injury. Since the S100B monomer dominates in the brain, we hypothesised that the S100BB dimer should be better related to outcome after severe traumatic brain injury than S100A1B or the "sum concentration". METHODS: Daily serum samples were collected from 59 patients with severe traumatic brain injury. Three different ELISA methods were used for measurements of S100B, S100A1B and S100BB respectively. Outcome was assessed after one year and categorised according to the Glasgow Outcome Scale. RESULTS: Serum levels of S100B, S100A1B and S100BB followed the same temporal course, with early maximum and rapidly decreasing values over the first days after the trauma. Maximum serum concentrations of each of the parameters were increased in the patient group with an unfavourable outcome compared with those with a favourable outcome (p = 0.01, 0.006 and 0.004, respectively). CONCLUSION: Both S100A1B and S100BB were related to outcome after severe traumatic brain injury. Even though this study is small, it seems unlikely that separate analyses of the dimers are of any advantage compared with measuring S100B alone.

Initial CSF total tau correlates with 1-year outcome in patients with traumatic brain injury.

OBJECTIVE: We investigated if tau, microtubular binding protein, in serum and ventricular CSF (vCSF) in patients with severe traumatic brain injury (TBI) during the initial posttraumatic days correlated to 1-year outcome. METHODS: Patients with severe TBI (n = 39, Glasgow Coma Scale score 2,126 pg/mL on days 2 to 3 discriminated between dead and alive (sensitivity of 100% and a specificity of 81%). A vCSF total tau level of >702 pg/mL on days 2 to 3 discriminated between bad (GOSE 1 to 4) and good (GOSE 5 to 8) outcome (sensitivity of 83% and a specificity of 69%). Patients with GOSE 1 (dead) had higher vCSF total tau levels on days 2 to 3 (p < 0.001) vs both surviving patients (GOSE 2 to 8) and those with NPH. Total tau was not detected in serum throughout the study. CONCLUSION: The increase in ventricular CSF (vCSF) total tau probably reflects axonal damage, known to be a central pathologic mechanism in traumatic brain injury (TBI). These results suggest that vCSF total tau may be an important early biochemical neuromarker for predicting long-term outcome in patients with a severe TBI.

CSF -neurofilament correlates with outcome after aneurysmal subarachnoid hemorrhage.

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating event. Following the bleeding, a number of pathophysiological changes and clinical factors determine outcome. Not surprisingly, attempts to predict outcome based on a single factor have failed. The neurological status graded at admission to hospital and distributions of the blood on CT are the strongest predictors. There is evidence that cerebrospinal fluid (CSF) proteins may serve as markers of the extent of brain damage. The present study is focused on the light unit of neurofilament protein (NFL), previously not evaluated in aSAH. Lumbar puncture (LP), neurological grading according to World Federation of Neurological Surgeons (WFNS) and neurological examination according to the National Institute of Health Stroke Scale (NIHSS) were performed in 48 consecutive patients with aSAH 10-14 days after the hemorrhage. CSF-NFL concentrations were analyzed using an ELISA. Outcome was assessed after 1 year and categorised according to the extended Glasgow Outcome Scale (GOSE). A significant correlation between CSF-NFL and GOSE was detected at follow up after 1 year. CSF-NFL also correlated with WFNS and NIHSS on the day of the lumbar puncture. CSF-NFL is a biochemical marker of brain damage correlating to neurological status and long-term outcome after aneurysmal subarachnoid hemorrhage.

Increased serum-GFAP in patients with severe traumatic brain injury is related to outcome.

OBJECTIVES: Several studies have established the relevance of S-100 in blood as a marker of brain damage after traumatic brain injury. However, a more specific marker is required and glial fibrillary acidic protein (GFAP) is considered to be a good candidate. METHODS: In order to assess the increase of GFAP in serum (s-GFAP) after a severe traumatic brain injury (TBI) we collected daily serum samples from 59 patients with severe TBI starting on the day of the trauma. S-GFAP was measured using a sandwich ELISA. The Glasgow outcome scale (GOS) assessed outcome after 1 year. RESULTS: All but one patient had maximal s-GFAP values above the laboratory reference value (median increased 10-fold). The highest detected levels were seen during the first days after TBI and then decreased gradually. Patients with unfavourable outcome had significantly (p<0.001) higher maximal s-GFAP values in the acute phase compared with patients with favourable outcome. All patients (n=5) with s-GFAP>15.04 microg /L died (reference level<0.15 microg/L). We found no significant difference in the maximal s-GFAP levels of patients with isolated brain injury in comparison with patients with multiple traumas. CONCLUSION: Serum-GFAP is increased during the first days after a severe traumatic brain injury and related to clinical outcome.

[Bilateral breast masses]. / Masses mammaires bilatérales.

A 76 year old woman is hospitalized for bilateral breast masses and neurological impairment. Her medical history is marked by rheumatoid arthritis treated with gold salts and methylprednisolone. Blood tests reveal pancytopenia; the MRI scan of the brain is suggestive of a CNS lymphoma. The pathologic examination of a breast mass specimen confirms the lymphoid nature of the neoplasm. This case report highlights the multifocal or systemic nature of non hodgkin's lymphoma and the diagnostic pitfalls of breast lymphomas. Rheumatoid arthritis and its medical management are reviewed for their possible roles in oncogenesis.

Expression of mRNA for phospholipase A2, cyclooxygenases, and lipoxygenases in cultured human umbilical vascular endothelial and smooth muscle cells and in biopsies from umbilical arteries and veins.

Arachidonic acid (AA) is released by phospholipase A2 (PLA2) and then converted into vasoactive and inflammatory eicosanoids by cyclooxygenases (COX) and lipoxygenases (LOX). These eicosanoids are important paracrine regulators of vascular permeability, blood flow, local pro- and anticoagulant activity and they play a major role in the local inflammatory response. We have investigated the presence of mRNAs for PLA2 and for isoforms of COX and LOX in both human endothelial cells (EC) and in human smooth muscle cells (SMC) in culture and in vascular biopsies of human umbilical veins (HUVB) and arteries (HUAB) by using the reversed transcription-polymerase chain reaction (RT-PCR) technique. Results show detectable levels of PLA2 type IV (cPLA2) in cultured EC and SMC and in vascular wall biopsies from HUAB and HUVB. The cultured EC and SMC demonstrate higher levels of both COX-1 and COX-2 with PCR analyses than do vascular wall biopsies from HUAB and HUVB. This indicates a difference in the native expression of COX-1 and COX-2 in cultures of EC and SMC compared to that in biopsies from intact vessel walls. The EC and SMC in culture do not express mRNA for 5-LOX, that was, however, expressed in the vascular wall biopsies. This speaks in favour of a constitutive, i.e. in vivo expression of 5-LOX in SMC in the vascular wall of both umbilical vein and arteries. Thus results from in vitro studies of constitutive COX and LOX expression in EC and vascular SMC in culture cannot simply be extrapolated to represent in vivo conditions.

Different induction mechanisms of mRNA for inducible nitric oxide synthase in rat smooth muscle cells in culture and in aortic strips.

The expression of mRNA for the inducible form of nitric oxide synthase, (iNOS), was studied in rat aortic smooth muscle cells, (SMCs) in cell culture and in strips of rat aorta by reverse transcriptase coupled to the polymerase chain reaction. iNOS mRNA expression was weak in cultured SMCs when exposed to either interferon-gamma (IFN gamma) or lipopolysaccharide (LPS), but the combination LPS+IFN gamma enhanced the expression. In aortic strips LPS alone induced a pronounced expression, with no further increase by IFN gamma. Cycloheximide potentiated the expression of iNOS mRNA in SMCs in culture stimulated with LPS+IFN gamma but attenuated the response in aortic strips. The results indicate different cellular signaling pathways for the induction of iNOS mRNA by LPS and/or IFN gamma, in cultured SMCs and in rat aortic strips.