Viable Mycobacterium avium subsp. paratuberculosis Colonizes Peripheral Blood of Inflammatory Bowel Disease Patients

Pathobionts, particularly Mycobacterium avium subsp. paratuberculosis (MAP) and Escherichia coli isolates with adherence/invasive ability (AIEC) have been associated with inflammatory bowel disease (IBD), particularly Crohn's disease (CD). This study aimed to evaluate the frequency of viable MAP and AIEC in a cohort of IBD patients. As such, MAP and E. coli cultures were established from faecal and blood samples (with a total n = 62 for each) of patients with CD (n = 18), ulcerative colitis (UC, n = 15), or liver cirrhosis (n = 7), as well as from healthy controls (HC, n = 22). Presumptive positive cultures were tested by polymerase chain reaction (PCR), for a positive confirmation of MAP or E. coli identity. E. coli-confirmed isolates were then tested for AIEC identity using adherence and invasion assays in the epithelial cell line of Caco-2 and survival and replication assays in the macrophage cell line of J774. MAP sub-culture and genome sequencing were also performed. MAP was more frequently cultured from the blood and faecal samples of patients with CD and cirrhosis. E. coli presumptive colonies were isolated from the faecal samples of most individuals, in contrast to what was registered for the blood samples. Additionally, from the confirmed E. coli isolates, only three had an AIEC-like phenotype (i.e., one CD patient and two UC patients). This study confirmed the association between MAP and CD; however, it did not find a strong association between the presence of AIEC and CD. It may be hypothesized that the presence of viable MAP in the bloodstream of CD patients contributes to disease reactivation.

DNA-based detection of Mycobacterium avium subsp. paratuberculosis in domestic and municipal water from Porto (Portugal), an area of high IBD prevalence

Mycobacterium avium subsp. paratuberculosis (MAP) may play a role in the pathology of human inflammatory bowel disease (IBD). Previously, we found a high frequency (98% in patients with active disease) of MAP DNA detection in the blood of Portuguese Crohn's Disease patients, suggesting this cohort has high exposure to MAP organisms. Water is an important route for MAP dissemination, in this study we therefore aimed to assess MAP contamination within water sources in Porto area (the residential area of our IBD study cohort). Water and biofilms were collected in a wide variety of locations within the Porto area, including taps connected to domestic water sources and from municipal water distribution systems. Baseline samples were collected in early autumn plus further domestic water samples in early winter, to assess the effect of winter rainfall. DNA was extracted from all 131 samples and IS900-based nested PCR used to assess the frequency of MAP presence. Our results show high MAP positivity in municipal water sources (20.7% of water samples and 41.4% of biofilm samples) and even higher amongst domestic sources (30.8% of water samples and 50% of biofilm samples). MAP positivity in biofilms correlated with positivity in water samples from the same sources. A significantly higher frequency of MAP-positivity was observed during winter rains as compared with samples collected in autumn prior to the winter rainfall period (61.9% versus 30.8%). We conclude that domestic and municipal water sources of Porto region have a high burden of MAP contamination and this prevalence increases with rainfall. We hypothesize that human exposure to MAP from local water supplies is commonplace and represents a major route for MAP transmission and challenge which, if positively linked to disease pathology, may contribute to the observed high prevalence of IBD in Porto district.

Human Immunodeficiency Virus (HIV) 2 Superinfection in a Patient Receiving Antiretroviral Therapy With Longstanding HIV-1 Viral Load Suppression

Dual human immunodeficiency virus (HIV) 1 and HIV-2 superinfections are rare but challenging. A HIV-1–infected patient receiving effective antiretroviral therapy was investigated for a severe CD4⁺ cell count decline. HIV-2 superinfection was diagnosed and genotypic test revealed mutations conferring resistance to most drug class, limiting options for treatment.

Life-Threatening Everolimus-Associated Pneumonitis: A Case Report and a Review of the Literature

INTRODUCTION

Noninfective pneumonitis is a class-related effect within mammalian target of rapamycin (mTOR) inhibitors, including everolimus, and can occasionally be severe.

CASE REPORT

A 62-year-old man, medicated with everolimus due to a heart transplantation 17 years previously and with chronic kidney disease, was admitted to the intensive care unit (ICU) with acute respiratory failure, cardiovascular shock, and impaired renal function requiring dialysis. Computed tomography (CT) scan revealed right upper lobe consolidation. Extensive microbiological workup, autoimmune testing, and cytology were negative and echocardiography showed preserved heart function. Everolimus levels were normal (5.7-6.1 ng/mL) and the drug was suspended at day 9. The patient was difficult to ventilate and responded poorly to broad-spectrum antibiotic and antifungal therapy. On day 25, CT scan and bronchoscopy revealed left-sided alveolar hemorrhage, and corticosteroid pulses were performed. The patient gradually improved. After discharge and 6 months of follow-up, clinical recovery was complete and chest imaging substantially improved.

DISCUSSION

Pneumonitis occurs in up to 4.3% of transplant recipients using everolimus for immunosuppression. Despite usually presenting as a mild and self-limited disease, severe cases have been described. Alveolar hemorrhage can occur and is associated with poor outcome. Everolimus levels do not seem to accurately predict toxicity. Corticosteroid therapy has been used with success in severe disease. We review the pathophysiological, clinical, and management-related aspects of this entity with emphasis on its potential severity.

CONCLUSION

Our case was a rare occurrence of severe life-threatening pulmonary disease related to everolimus. Awareness of the potential severity of this entity is important for the management of patients using mTOR inhibitors.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Pain reduction and improvement of function following ultrasound-guided intra-articular injections of triamcinolone hexacetonide and hyaluronic acid in hip osteoarthritis

The scientific literature has shown positive results regarding intra-articular injections of hyaluronic acid in osteoarthritic joints. When injecting in the hip joint, the guidance of ultrasound can provide higher injection accuracy and repeatability. However, due to the methodological limitations in the current available literature, its recommendation in the current practice is still controversial. This study shows that ultrasound-guided intra-articular injections of triamcinolone hexacetonide and hyaluronic acid can improve pain, function and quality of life in patients with symptomatic and radiographic hip osteoarthritis. In addition, the administration of triamcinolone hexacetonide and hyaluronic acid to the hip joint in these patients can delay the need for interventional surgery.

[Ankle arthroscopy in treatment of Bosworth fracture]

The Bosworth fracture is a pattern of fracture-dislocation of the ankle joint with fixed dislocation of the proximal part of the fibula behind the posterior malleolus. It is a rare injury, which requires high index of suspicion for diagnosis. Fixed dislocation of the fibula does not allow for closed reduction, so open reduction and fixation of fibula or tibia is required. We present a case report of a patient who suffered a Bosworth fracture, with associated medial malleolus fracture. She underwent surgical treatment with open reduction and internal fixation of the fibula and tibia. We also performed anterior arthroscopy of the ankle, to evaluate the tibiofibular syndesmosis, remove loose osteochondral fragments, and perform debridement and microfracture of unstable chondral lesions of the talus. One year after injury, she remains with occasional pain and a normal range of motion comparing to the contralateral ankle joint. Bosworth fracture is a serious and rare injury, which requires early diagnosis and urgent surgical treatment. Performing ankle arthroscopy in the acute treatment of the Bosworth fracture allows for diagnosis and treatment of associated intra-articular injuries, as well as assisting with adequate fracture reduction and evaluation of the tibiofibular syndesmosis stability.

Ischaemic stroke in HIV-infected patients: a case-control study

OBJECTIVES

The aim of the study was to provide insights into the contributions of HIV infection stage, antiretroviral therapy (ART) and vascular risk factors to the occurrence of ischaemic stroke in HIV-infected patients.

METHODS

We performed a case-control study of HIV-infected patients followed in our clinic. We compared patients hospitalized between January 2006 and June 2014 with an ischaemic stroke or transient ischaemic attack to age- and gender-matched controls without stroke.

RESULTS

Of 2146 patients followed in our clinic, we included 23 cases (20 men and three women; mean age 51.3 years) and 23 controls. Eighty-three per cent of cases had had a stroke and 17% a transient ischaemic attack. According to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, small-vessel occlusion was the most frequent aetiology, followed by large-artery atherosclerosis and cardioembolism. Compared with controls, stroke was statistically significantly associated with diabetes, smoking and low concentrations of high-density lipoprotein (HDL) cholesterol. Illegal drug use, a low CD4 count and a high viral load were also associated with ischaemic cerebral events. There were no statistically significant differences between cases and controls in Centers for Disease Control and Prevention (CDC) HIV stage, CD4 count nadir and HIV infection time-to-event. No statistically significant differences were found concerning ART or treatment compliance.

CONCLUSIONS

In our single centre study, we found associations of illegal drug use, HIV replication and some traditional vascular risk factors with the occurrence of ischaemic cerebral events. The paradigm of the care of HIV-infected patients is changing. Concomitant diseases in the ageing patient with HIV infection, including cerebrovascular disease, must also be addressed in view of their impacts on morbidity and mortality. Apart from controlling the HIV infection and immunosuppression with ART, vascular risk factors must also be addressed.

An unusual case of delayed-type hypersensitivity to ceftriaxone and meropenem

Recent studies have demonstrated a low cross-reactivity between β-lactam antibiotics and carbapenems in IgE-mediated reactions. There are no studies on cross-reactivity of meropenem in patients with non-immediate hypersensitivity to cephalosporins. We describe a case of a 13-year-old male, admitted in Neurosurgery with a severe extradural empyema complicating frontal sinusitis, submitted to an emergent bifrontal craniotomy. A generalized maculopapular exanthema, fever and malaise, appeared by the 7th day of meningeal doses of ceftriaxone, clindamycin and vancomycin. Those were replaced by meropenem, with posterior worsening of the reaction and mucosal involvement. A new scheme with amikacin, metronidazole and linezolid was done with improvement. Skin prick, intradermal and patch tests to penicillins, ceftriaxone and meropenem were negative. Lymphocyte transformation test was positive to ceftriaxone and negative to meropenem.Non-immediate T cell mechanism seems to be involved. Diagnosis work-up couldn't exclude cross-reactivity between ceftriaxone and meropenem.

IL-4 and IL-6 levels and adipose tissue distribution in HIV-1 patients under antiretroviral therapy

PURPOSE

Combined antiretroviral therapy (cART) for the treatment of HIV-1 infection has been associated with complications, including lipodystrophy. Several interleukins have been implicated in the pathology and physiology of lipodystrophy. The present study aimed to compare the levels of IL-4 and IL-6 in HIV-1 patients under cART with and without, clinically and fat mass ratio defined, lipodystrophy and in four different groups of fat distribution: (1) no lipodystrophy; (2) isolated central fat accumulation; (3) isolated lipoatrophy and (4) mixed forms of lipodystrophy.

METHODS

In the present cross-sectional study we evaluated IL-4 and IL-6 levels, insulin resistance and insulin sensitivity indexes in 86 HIV-infected adults under cART.

RESULTS

No significant differences in IL-4 and IL-6 levels between the four groups of body composition were observed. Patients with HOMA-IR >4 presented higher levels of IL-6 and lower levels of IL-4, although without statistical significance. No correlation between IL-6, or IL-4, HOMA-IR and quantitative body fat mass distribution was found.

CONCLUSION

Although there was a tendency for patients with isolated lipoatrophy and isolated fat accumulation to present higher IL-6 levels, these differences were not statistically significant. No differences were found relating IL-4 levels.

Prevalence of Mycobacterium avium subsp. paratuberculosis and Escherichia coli in blood samples from patients with inflammatory bowel disease

Mycobacterium avium subsp. paratuberculosis (MAP) and adherent-invasive Escherichia coli (AIEC) have been implicated as primary triggers in Crohn's disease (CD). In this study, we evaluated the prevalence of MAP and E. coli (EC) DNA in peripheral blood from 202 inflammatory bowel disease (IBD) patients at various disease periods and compared against 24 cirrhotic patients with ascites (CIR) (non-IBD controls) and 29 healthy controls (HC). MAP DNA was detected by IS900-specific nested PCR, EC DNA by malB-specific nested PCR and AIEC identity, in selected samples, by sequencing of fimH gene. CD patients with active disease showed the highest MAP DNA prevalence among IBD patients (68 %). Infliximab treatment resulted in decreased MAP detection. CIR patients had high individual and coinfection rates (75 % MAP, 88 % EC and 67 % MAP and EC), whilst HC controls had lower MAP prevalence (38 %) and EC was undetectable in this control group. EC DNA prevalence in IBD patients was highly associated with CD, and 80 % of EC from the selected samples of CD patients analyzed carried the fimH30 allele, with a mutation strongly associated with AIEC. Our results show that coinfection with MAP and AIEC is common and persistent in CD, although the high MAP and EC detection in CIR patients suggested that colonization is, at least, partially dependent on increased gut permeability. Nevertheless, facilitative mechanisms between a susceptible host and these two potential human pathogens may allow their implication in CD pathogenesis.

Infliximab therapy increases the frequency of circulating CD16(+) monocytes and modifies macrophage cytokine response to bacterial infection

Crohn's disease (CD) has been correlated with altered macrophage response to microorganisms. Considering the efficacy of infliximab treatment on CD remission, we investigated infliximab effects on circulating monocyte subsets and on macrophage cytokine response to bacteria. Human peripheral blood monocyte-derived macrophages were obtained from CD patients, treated or not with infliximab. Macrophages were infected with Escherichia coli, Enterococcus faecalis, Mycobacterium avium subsp. paratuberculosis (MAP) or M. avium subsp avium, and cytokine levels [tumour necrosis factor (TNF) and interleukin (IL)-10] were evaluated at different time-points. To evaluate infliximab-dependent effects on monocyte subsets, we studied CD14 and CD16 expression by peripheral blood monocytes before and after different infliximab administrations. We also investigated TNF secretion by macrophages obtained from CD16(+) and CD16(-) monocytes and the frequency of TNF(+) cells among CD16(+) and CD16(-) monocyte-derived macrophages from CD patients. Infliximab treatment resulted in elevated TNF and IL-10 macrophage response to bacteria. An infliximab-dependent increase in the frequency of circulating CD16(+) monocytes (particularly the CD14(++) CD16(+) subset) was also observed (before infliximab: 4·65 ± 0·58%; after three administrations: 10·68 ± 2·23%). In response to MAP infection, macrophages obtained from CD16(+) monocytes were higher TNF producers and CD16(+) macrophages from infliximab-treated CD patients showed increased frequency of TNF(+) cells. In conclusion, infliximab treatment increased the TNF production of CD macrophages in response to bacteria, which seemed to depend upon enrichment of CD16(+) circulating monocytes, particularly of the CD14(++) CD16(+) subset. Infliximab treatment of CD patients also resulted in increased macrophage IL-10 production in response to bacteria, suggesting an infliximab-induced shift to M2 macrophages.

Acute hepatitis E complicated by Guillain-Barre syndrome in Portugal, December 2012--a case report

Autochthonous hepatitis E virus (HEV) infection has been increasingly reported in Europe and the United States, mostly arising from genotype 3 and less frequently genotype 4. We report here on a patient with HEV genotype 3a infection complicated by Guillain-Barré syndrome in Portugal in December 2012. We draw attention to the diagnosis of autochthonous HEV infection and to its rare, but important, neurological complications.

Prevalence of obesity and its relationship to clinical lipodystrophy in HIV-infected adults on anti-retroviral therapy

BACKGROUND

Combination antiretroviral therapy (cART) is associated with lipodystrophy (lipoatrophy and lipoaccumulation) and several metabolic abnormalities that together can contribute to an increased cardiovascular risk. The aim of this study was to evaluate the prevalence of obesity in patients on cART according to the presence of clinical lipodystrophy (CL) and to analyze factors associated with obesity.

METHODS

We evaluated 368 HIV-infected adults on cART.

RESULTS

CL was present in 59.0%. Independently of gender, patients with CL were more frequently underweight [5.7% (21/368)] and of normal weight [47.3% (174/368)], and less frequently overweight [33.2% (122/368)] or obese [13.9% (51/368)]. Mean body mass index was higher in patients with abdominal prominence regardless of the presence of clinical lipoatrophy. Patients with CL had lower waist circumference, higher waist/hip and fat mass ratio and lower total and subcutaneous fat, without significant difference in visceral fat but with a higher visceral/subcutaneous fat ratio, as evaluated by CT at abdominal level. CL was significantly less frequent in overweight [odds ratio (OR)=0.21, 95% confidence interval (CI): 0.05-0.92] and obese (OR=0.05, 95%CI: 0.01-0.26) patients, when compared to underweight ones, independent of age, gender, duration of infection, cART regimen, virological suppression, and HIV-infection risk factor.

CONCLUSIONS

Being overweight or obese is highly prevalent in HIV-infected patients on cART. Patients with CL were more frequently under- or normal weight, and less frequently overweight or obese. Obesity is a condition that should be considered in HIV patients on cART.

Population mobility and the changing epidemics of HIV-2 in Portugal

INTRODUCTION

Portugal is the European country with the highest frequency of HIV-2 infection, which is mainly concentrated in West Africa. The cumulative number of notified HIV-2 infections in Portugal was 1813 by the end of December 2008. To better characterize the dynamics of HIV-2 infection in the country and to obtain data that may be of use in the prevention of the spread of HIV-2, we evaluated a large pooled sample of patients.

PATIENTS AND METHODS

Five Portuguese hospitals provided data on HIV-2-infected patients from 1984 to the end of 2007. Data concerning demographic characteristics and clinical variables were extracted. Patients were stratified according to date of diagnosis in approximately 5-year categories.

RESULTS

The sample included 442 patients, accounting for 37% of all HIV-2 infections notified in Portugal during that period. HIV-2-infected patients showed clearly different characteristics according to the period of diagnosis. Until 2000, the majority of HIV-2-infected patients were Portuguese-born males living in the north of the country. From 2000 to 2007, most of the patients diagnosed with HIV-2 infection had a West African origin, were predominantly female and were living in the capital, Lisbon. The average age at diagnosis and loss to follow-up significantly increased over time.

CONCLUSION

HIV-2 infection has been documented in Portugal since the early 1980s and its epidemiology appears to reflect changes in population movement. These include the movements of soldiers and repatriates from African territories during the independence wars and, later, migration and mobility from high-endemicity areas. The findings of this study stress the importance of promoting migrant-sensitive health care.

Assessment of body fat composition disturbances by bioimpedance analysis in HIV-infected adults

HIV-lipodystrophy syndrome is characterized by different patterns of body fat distribution (BFD) which are identified by clinical and body composition (BC) assessment, including bioimpedance analysis (BIA). Our aim was to compare BC in HIV-infected patients on combination antiretroviral therapy (cART) according to 4 distinct phenotypes of BFD (G1-no lipodystrophy, G2-isolated central fat accumulation, G3-lipoatrophy, G4-mixed forms of lipodystrophy) and assessed factors associated with them. Anthropometry and BIA were performed in 344 HIV-1 patients. G2 and G4 phenotype patients had significantly higher fat mass (FM) but no differences were observed in fat-free mass (FFM) and total body water among the 4 phenotypes. Significant negative associations were found between the presence of lipoatrophy and female gender, body mass index (BMI), waist (WC), hip (HC) and thigh circumferences, and total body FM estimated by BIA. After adjustment for gender, cART duration and BMI, G3 had significant lower WC [odds ratio (OR)=0.84; 0.78- 0.90] and HC (OR=0.88; 0.81-0.96) mean. Independently of gender, cART duration and BMI, G2 remained significantly associated with higher WC (OR=1.11; 1.05-1.18) and HC (OR=1.15; 1.07-1.23) mean, and with FM estimated by BIA [FM as %, OR=1.17 (1.09-1.26); and FM as kg, OR=1.15 (1.06- 1.25)]. There was a significant positive association between G4 and female gender (OR=1.66; 1.01-2.75), BMI (OR=1.10; 1.04-1.17) and WC (OR=1.15; 1.09-1.21). The similar FFM along the BFD spectrum describes the actual BC of these patients without sarcopenia. In a clinical setting, BIA is an easy and useful tool to evaluate fat mass and FFM and gives us a picture of BC that was not possible with anthropometry.

Mercury chloride effects on the function and cellular integrity of sea bass (Dicentrarchus labrax) head kidney macrophages

The objective of this work was to study mercury chloride effects on the function and integrity of sea bass (Dicentrarchus labrax) head kidney macrophages (S-HKM), and to evaluate the response of HgCl2-exposed cells to macrophage activating factor(s) (MAF) produced by sea bass head kidney leukocytes. There was considerable variability in the effects of HgCl2 on the production of reactive oxygen species (ROS) by S-HKM. When incubated with HgCl2, cells from five out of nine fish tested showed a decrease in ROS production as compared to cells incubated with medium alone. In those cultures, MAF addition prevented the mercury chloride-induced decrease in ROS production. In other S-HKM cultures isolated from different fish, mercury chloride abrogated the up-regulating effect of MAF on the respiratory burst. MAF activation of the phagocytic activity of S-HKM was also impaired by HgCl2 addition. Mercury chloride induced apoptosis in S-HKM cultures and MAF addition prevented this effect.

Modulation of the activity of sea bass (Dicentrarchus labrax) head-kidney macrophages by macrophage activating factor(s) and lipopolysaccharide

The aim of this study was to establish the requirements for macrophage activating factor (MAF) production by sea bass head-kidney leucocytes and the kinetics of macrophage activation when exposed to MAF-containing supernatants and/or lipopolysaccharide (LPS), a known macrophage stimulant. MAF activity was found in culture supernatants of total head-kidney leucocytes pulsed with 5 microg ml(-1)Con A, 5 or 10 ng ml(-1)PMA and 100 ng ml(-1)calcium ionophore, or 10 microg ml(-1)Con A alone, as assessed by the capacity to prime macrophages for enhanced production of reactive oxygen intermediates (ROI). Mixed leucocyte cultures from two or eight fish showed higher MAF activity after stimulation, indicating that a mixed leucocyte reaction was also important for MAF production. MAF-induced activation of macrophage cultures was highest at 18 h of exposure and was lost by 72 h except for MAF induced by Con A-stimulation alone. LPS primed macrophages for increased ROI production at early incubation times and down-regulated ROI production after 24 h. LPS had no effect in further stimulating the MAF-induced priming effect on production of ROI and down-regulated the MAF-priming by 48 h. Sea bass head-kidney macrophages did not show increased nitrite production when exposed to MAF and/or LPS, which may be related to their differentiation status.

[Various criteria for the choice of the empirical antibiotic treatment of pneumonia in intensive care]

In this paper we present a synopsis of the recommendations of three Consensus Conferences (from the American Thoracic Society and the American Society of Infectious Diseases) for the empirical antibiotic treatment of severe community and hospital acquired pneumonia. Several groups are defined according to the existence of specific risk factors, severity of the disease and timing of the onset of pneumonia (in the case of nosocomial pneumonia). Each group has more likely pathogens and several antimicrobial agents are proposed. However the option must always rely on the local microbiological sensitivity pattern.

[Activities at an Infectious Disease Intensive Care Unit (1988-1997)]

The practice of an Infectious Diseases Intensive Care Unit for a period of ten years (1988-1997) is reviewed. In this time 1,191 patients were treated--822 had more than 15 years of age and 369 were younger. The occupation rate ranged between 74.4% and 90.8%, and the mean patient stay in the UCI ranged between 6.7 and 12.5 days. Nine hundred and forty-four patients were discharged cured or improved during the stay and 247 (20.7%) died. The most frequent pathologies were: meningitis--371 patients (33.6%); encephalitis--103 (8.6%); and tetanus 143 (12.0%) patients. The morbidity and mortality of different pathologies admitted to the Intensive Care Unit are presented. The mortality rate of the two most common diseases (meningitis and tetanus) is discussed. The need for Intensive Care in the field of Infectious Diseases is stressed.

Dynamics of experimental vasogenic brain oedema in the rat: changes induced by adrenergic drugs

The effects of adrenergic drugs on the formation and resolution of cerebral oedema in a rat model of cold-induced vasogenic brain oedema were studied. Evans blue dye extravasation, water content and ultrastructural alterations (pinocytotic vesicle formation in capillary endothelial cells and apparent water accumulation in the brain parenchyma) were evaluated in parietal cortex. Previous administration of the alpha-adrenoceptor antagonist phenoxybenzamine produced a reduction of Evans blue extravasation and water content, diminished vesicle formation and reduced water accumulation. Previous administration of the beta2-adrenoceptor agonist clenbuterol reduced Evans blue extravasation and water content, but did not change vesicle frequency. The effects of clenbuterol on Evans blue passage to the brain were blocked by timolol (beta-adrenoceptor antagonist) but not by metoprolol (selective beta1-adrenoceptor antagonist). When given after the application of cold, clenbuterol was also able to reduce Evans blue and water content in the brain. Isoprenaline (beta-adrenoceptor agonist that does not cross the blood-brain barrier) showed a reduction in Evans blue extravasation only when given intracerebroventricularly. Vinblastine (a drug that prevents vesicle formation) produced a reduction of the amount of pinocytotic vesicles. We conclude that there is an influence of the central adrenergic nervous system on the formation and/or resolution of vasogenic brain oedema and that the alterations on water movement and Evans blue transport mediated by adrenergic drugs seem to be due, at least in part, to alterations of pinocytotic activity in capillary endothelial cells.

Effect of mechanogated membrane ion channel blockers on experimental traumatic brain oedema

Traumatic head injury leads to marked swelling of endothelial cells, both in human patients and in Marmarou's rat model. We used this model to test the hypothesis of mechanogated ion channels being involved in the formation of traumatic brain oedema. All mechanogated channel blockers tested (gadolinium, amiloride, gentamicin) significantly reduced traumatic brain oedema evaluated by Evans blue extraction ratio, either when given 15 minutes before or 30 minutes after induction of trauma (evaluation 2 hours after trauma). These results clearly support our hypothesis, opening a new way for the investigation of the treatment of a clinical situation endowed with high morbidity and mortality.

Hepatitis C virus genotypes and the influence of the induction of immunosuppression with anti-thymocyte globulin (ATG) on chronic hepatitis in renal graft recipients

Hepatitis C virus (HCV) exhibits a dramatic genetic variability and several mechanisms of immunological response are unable to control hepatic and extrahepatic replication. Genotype 1 b is associated with more severe clinical manifestations and is less responsive to interferon. In addition, we have reported an increase of HCV RNA viral load after renal transplantation. Anti-thymocyte globulin (ATG) is supposed to increase viral replication and liver dysfunction in chronically infected renal graft recipients. We evaluated the genotype profile in HCV+ patients of our Renal Transplant Unit and studied the effects of ATG, as part of the induction of immunosuppression, on viral load and liver enzymes abnormalities. From 726 renal graft recipients, 104 patients, with a mean follow up of 3.9 +/- 2.9 years, were anti-HCV+ by ELISA II. HCV RNA was measured by quantitative PCR. We correlated the viral load and biochemical liver parameters with genotype, exposure to ATG as induction therapy, early acute rejection episode and the duration of infection. Of the 81 patients tested, 72% were viraemic and genotype 1 b was the predominant viral strain (66%). The majority of these patients (65%) were coinfected by two or more strains. There was no correlation between HCV RNA blood levels and liver enzymes. We did not find higher viral load with genotype 1 b infection (68 +/- 88 mEq/ml vs 75.8 +/- 123 mEq/ml in the others) nor with ATG induction therapy (43.5 +/- 71.3 mEq/ml vs 64.1 +/- 110.5 mEq/ml). Early acute rejection and longer follow up were not associated with higher levels of HCV RNA. The biochemical liver profile showed no relationship with the variables studied. We concluded that genotype 1 b is the predominant strain in our HCV+ population and there is a great prevalence of coinfection with several genotypes. Our results did not confirm a deleterious effect of the use of ATG as induction therapy in these HCV-infected patients. Prospective randomised studies with liver biopsy evaluation are needed to answer more fully the remaining questions about the best immunosuppressive therapy in renal graft recipients with chronic HCV infection.

Experimental traumatic cerebral contusion: morphological study of brain microvessels and characterization of the oedema

Several experimental brain oedema models are currently available, but most of them are very different from what happens in clinical practice. As it is simple and seems to replicate the range of injuries seen in man we decided to evaluate Marmarou's model of head injury in order to test physiopathogenic and therapeutic hypotheses. Three groups of Wistar rats weighting 360-400 gr, anaesthetized with sodium pentobarbitone and breathing spontaneously, without tracheal intubation, were studied. In the first group six animals were killed two hours after injury and the brain's water content compared with that of nine controls. In another group Evans blue (100 mg/kg) was injected one hour before trauma and dye's extraction ratio determined at various times after injury: five animals at 15 minutes, six at 30 minutes, five at 60 minutes and nine at 120 minutes. A total of twenty-eight animals served as controls. In the last group morphological studies with light and electron microscopy were performed in the traumatized brain tissue from rats killed 5 and 120 minutes after injury and in brain tissue from control rats. Results showed that Marmarou's brain trauma model induced perivascular brain oedema, already visible at the ultrastructural level 5 minutes after the injury. Endothelial cells themselves were "oedematiated", rich in pinocytotic vesicles and membrane blebs, and presented intact tight junctions. Two hours after trauma the perivascular oedema was more marked. At this time the brain water content was significantly higher than that in controls. Evans blue extraction ratio increased linearly with time, being significantly higher than in controls 120 minutes after injury. We conclude that Marmarou's model is a suitable model for the study of brain oedema induced by trauma, and that this oedema, assessed by three different methodologies, was statistically significant two hours after injury.

Abnormal extrapelvic course of the inferior gluteal artery

At its extrapelvic course the inferior gluteal a. is found to be strictly related to the sciatic n. This relationship has been described in a general way, emphasizing its medial localization in respect to the nerve. Clinicosurgical reports describe cases of aneurysms of the inferior gluteal a. on its extrapelvic course and subsequent compression at the nerve. In order to get further details on the relationship between these two structures, 80 gluteal regions from 40 cadavers of adult Brazilian individuals, 29 males and 11 females, were dissected. The inferior gluteal a. was found medial to the sciatic n. in 62 cases (77.5%); in the 18 remaining (22.5%) the trunk of the artery or one of its branches perforated the nerve. Of these, 14 (77.8%) were males and 4 (22.2%) females. This disposition was found 8 times (44.4%) on the right and 10 (55.6%) on the left side; was unilateral in 4 individuals (1 on the right and 3 on the left side) and bilateral in 7. The course of the inferior gluteal a. through the sciatic n. and/or the presence of aneurysms of this artery should be considered as a possible cause of nerve compression.

Ultrastructural study of brain microvessels in patients with traumatic cerebral contusions

Brain tissue from 11 patients with traumatic cerebral contusions submitted to surgery was studied. Control biopsy specimens were obtained from 5 patients undergoing ventriculo-peritoneal shunts for "communicating" hydrocephalus. After collection, the small fragments were fixed by immersion in glutaraldehyde-osmium and embedded in Epon. Semi-thin sections stained with toluidine blue were observed with the light microscope. Thin sections stained with lead citrate and uranyl acetate were observed using a Jeol electron microscope. In tissues from patients with head trauma a clear space most probably corresponding to fluid accumulation was systematically observed around microvessels. Ultrastructurally endothelial cells from these specimens exhibited signs of marked intracellular oedema, tight junctions being intact. Pinocytotic activity was increased, mainly at the abluminal surface. Swelling of astrocytic perivascular processes and the appearance of macrophagic cells with voluminous lysosomes were also observed. The authors conclude that the oedema of endothelial cells probably represent a central fact in the pathophysiology of traumatic brain oedema and speculate on the putative involvement of stretch-activated receptors in this condition.

Involvement of reactive oxygen intermediates in tumor necrosis factor alpha-dependent bacteriostasis of Mycobacterium avium

We studied the involvement of reactive oxygen intermediates and reactive nitrogen intermediates in the bacteriostasis of two Mycobacterium avium strains differing in virulence by resident peritoneal macrophages. We found that both the highly virulent strain (25291) and the low-virulence strain (1983) of M. avium induced superoxide production but inhibited nitrite production in vitro. This inhibition was due to the production of superoxide, a nitric oxide scavenger. The stimulation of superoxide production was two- to fivefold higher in strain 1983-infected than in strain 25291-infected resident peritoneal macrophages and was independent of contaminating T cells or NK cells. Superoxide secretion was dependent on the tumor necrosis factor (TNF) produced endogenously by the macrophages. This was also true when macrophages were isolated from infected mice. Addition of TNF to the infected resident peritoneal macrophages caused only a slight, albeit significant, increase in superoxide production by strain 25291-infected macrophages. Incubation of resident peritoneal macrophages with different scavengers of reactive oxygen intermediates showed that strain 1983 was susceptible to hydrogen peroxide produced by resident peritoneal macrophages. Strain 25291 was shown to decrease superoxide secretion inside heavily infected bone marrow-derived macrophages. This strain was also shown to be a better trigger for production of reactive oxygen intermediates than strain 1983. In summary, strain 1983 induced high levels of TNF synthesis that acted in an autocrine fashion to stimulate production of reactive oxygen intermediates by macrophages leading to growth restriction mediated by hydrogen peroxide. The highly virulent strain 25291 induced low levels of TNF synthesis, and therefore little reactive oxygen intermediate production, and could also inhibit superoxide production by the infected macrophages.