Chemistry of free radicals produced by oxidation of endogenous α-aminoketones. A study of 5-aminolevulinic acid and α-aminoacetone by fast kinetics spectroscopy.

BACKGROUND: Excess 5-aminolevulinic acid (ALA) and α-aminoacetone (AA) are implicated in ketosis, porphyrinpathies and diabetes. Pathologic manifestations involve O2⁻, H2O2, OH, enoyl radicals (ALA and AA) and their oxidation end products. METHODS: To characterize enoyl radicals resulting from reaction of OH radicals with ALA and AA, micromolar OH concentrations were produced by pulse radiolysis of ALA and AA in aqueous solutions. RESULTS: ALA and AA react with OH at k=1.5 × 109 M⁻¹s⁻¹. At pH7.4, the ALA absorbance spectrum has a maximum at 330 nm (ε=750 M⁻¹cm⁻¹). This band appears as a shoulder at pH8.3 where two ALA species are present: (NH3)⁺-CH2-CO-CH2-CH2-COO⁻ and NH2-CH2-CO-CH2-CH2-COO⁻ (pKa=8.3). At pH8.3, ALA reacts with oxygen (k=1.4 × 108 M⁻¹s⁻¹) but not with O2⁻. At pH8.3, AA oxidation produces two AA species characterized by an absorbance spectrum with maxima at 330 and 450 nm. ALA and AA are repaired by antioxidants (quercetin (QH), catechin, trolox, ascorbate) which are semi-oxidized (k>10(8)M⁻¹s⁻¹). QH bound to HSA or to apoferritin and ferritin repairs ALA and AA. In O2-saturated apoferritin solutions, Q, O2⁻, AA and reaction product(s) react with QH. CONCLUSIONS: The optical absorption properties and the time evolution of ALA and AA were established for the first time. These radicals and their reaction products may be neutralized by antioxidants free in solution or bound to proteins. GENERAL SIGNIFICANCE: Adjuvant antioxidant administration may be of interest in pathologies related to excess ALA or AA production.

Serum procalcitonin does not differentiate between infection and disease flare in patients with systemic lupus erythematosus.

Systemic erythematosus lupus (SLE) is a common autoimmune disease. Disease flares may mimic infection with fever, inflammatory syndrome and chills, sometimes resulting in a difficult differential diagnosis. Elevated serum procalcitonin (PCT) levels have been reported to be predictive of bacterial infections, but with conflicting results. The value of serum procalcitonin has not been assessed in large series of SLE. We aimed to describe the distribution of PCT levels in SLE patients with and without flares, to assess the factors associated with increased PCT levels, and to determine the positive and negative predictive values of increased PCT for bacterial infection in SLE patients. Hospitalized SLE patients were included in a retrospective study. Serum PCT had been assayed, or a serum sample had been frozen on admission, before treatment modification. Serum PCT, measured by an automated immunofluorometric assay, and SLEDAI were assessed at the same time. Some 53 women (median age: 33.7 years, range 16-76) and seven men (median age: 52.5 years ± 19) were included. The median SLEDAI for patients with flare (n = 16, 28%) was 2 (range: 0-29). Five patients (8%) had systemic infection. Only one patient had increased PCT levels. Men had significantly higher PCT levels than women (0.196 ± 0.23 versus 0.066 ± 0.03, p < 0.01) and a significant correlation was observed between PCT, age, erythrocyte sedimentation rate, and C-reactive protein. We conclude that PCT levels were within the normal range in infected and non-infected SLE patients and there was no ability to differentiate SLE patients with or without bacterial infection.

Pathological features of temporal arteries in patients with giant cell arteritis presenting with permanent visual loss.

BACKGROUND: Permanent visual loss (PVL) is the most feared complication of giant cell arteritis (GCA), and its risk factors are still unclear. OBJECTIVES: The aim of our study was to assess the pathological features predictive of PVL on temporal artery biopsy (TAB) specimens in patients with GCA. METHODS: The slides of 391 TAB specimens from patients with GCA were reviewed by two pathologists without clinical information. RESULTS: A total of 29 patients (26 females and 3 males, mean age 78.3 years) presented with unilateral PVL at the onset of the disease, and 362 patients (258 females, 104 males, mean age 74.7 years), did not. The pathological features strongly predictive for PVL were the presence (p = 0.003), number (p = 0.001) and aggregates of giant cells (p = 0.001), presence of plasmocytes (p = 0.002), thickened intima (p = 0.007), neoangiogenesis (p = 0.001) and degree of arterial occlusion (p = 0.006). Presence of neutrophils, eosinophils, parietal necrosis, calcification in the arterial wall and disruption of the internal elastic membrane were similar in both groups. Total obstruction of the arterial lumen by a thrombus, intensity of the inflammatory cells infiltration and inflammation of small vessels, nerves and veins surrounding the temporal artery were not associated with blindness. In multivariate analysis, only giant cells remained significantly associated with PVL. CONCLUSION: Giant cells are strongly associated with PVL, with a significant gradient between great risk and large number of giant cells. However, PVL was neither associated with the intensity of the inflammatory infiltrate, nor with the presence of arterial thrombosis.

Procalcitonin at the onset of giant cell arteritis and polymyalgia rheumatica: the GRACG prospective study.

OBJECTIVES: An epidemic pattern has been reported for GCA and PMR. Immunological studies have shown that an unknown antigen activates the dendritic cells of the adventitia and the type 4 toll-like receptors. Procalcitonin (PCT) is an early marker of bacterial infection. The goal of the study was to assess the level of PCT in GCA and PMR at the onset of the disease. METHODS: Patients diagnosed during the 2002-06 period were randomly selected. All the 46 patients fulfilled the ACR or the Hunder criteria, and all blood samples were taken before steroid therapy. RESULTS: PCT was normal in all patients. PCT was slightly increased in men (0.087 +/- 0.023 microg/l) compared with women (0.066 +/- 0.027 microg/l) (P = 0.009), and in PMR (0.092 +/- 0.027 microg/l) compared with GCA (0.068 +/- 0.026 microg/l) (P = 0.018). There was no significant correlation with inflammation markers. CONCLUSIONS: These results are not in favour of a bacterial trigger for GCA or PMR. Increased PCT levels in patients with inflammatory syndrome, GCA-PMR symptoms and negative temporal artery biopsy may rule out the diagnosis of GCA and PMR.

[Haematopoietic stem cell transplantation in the treatment of autoimmune diseases]. / Intensification thérapeutique dans les maladies auto-immunes.

PURPOSE: During the past ten years, more than 1000 patients suffering from severe autoimmune disease have received an autologous haematopoietic stem cell transplant. These new therapeutic have been used in systemic sclerosis (scleroderma), multiple sclerosis, rheumatoid arthritis, juvenile idiopathic arthritis and systemic lupus erythematosus. CURRENT KNOWLEDGE AND KEY POINTS: Autologous haematopoietic stem cell transplantation has become a curative option for condition with very poor prognosis as severe systemic sclerosis, lupus erythematosus or other systemic diseases. This review summarizes the current experience in the phase I and II clinical trials in Europe and North America. We describe the main results and the limits of stem cell transplantation in systemic diseases. FUTURE PROSPECTS AND PROJECTS: Autologous haematopoietic stem cell transplant in the treatment of autoimmune disease has evolved from a experimental concept to a clinically feasible and powerful therapy for selected patients with severe disease.

[Grand types of studies 2: analytical studies]. / Les grands types d'étude 2: les études analytiques.

PURPOSE: This paper describes the hierarchy of analytical studies, from the observational studies to the experimental ones. STATE OF THE ART AND MAIN POINTS: Case-control studies, the most frequently performed among analytical studies, may generate or confirm hypotheses. They are of particular use for rare diseases. Cohort studies aim mainly at confirming hypotheses already tested, and at precisely quantifying the magnitude of effect. Randomisation aims at the elimination of confounding factors, and meta-analysis, at decreasing potential selection biases and increasing power. Those goals may not always be achieved. PERSPECTIVES AND PROJETS: The study power, or the beta error, are major factors to be determined when designing a study, before any attempt of realization.

[Grand types of clinical studies]. / Les grands types d'études cliniques 1: de la description à l'analyse.

PURPOSE: This paper provides an overview of the hierarchy between the main descriptives clinical studies, with their respective weaknesses and strength. STATE OF THE ART AND MAIN POINTS: Case-reports and case-series are first described, which do not provide control groups but have been very useful in disease recognition and nosology building. Ecological studies, which are hypothesis generating at the group or population level, but which do not study individuals, and prevalence studies with one simple or a double question, which study individuals within groups but may lead to erroneous conclusions so far are risk factors are involved, are then reviewed. PERSPECTIVES AND PROJECTS: The overview of the descriptive studies leads to the notion of confounding factor, which may be better addressed by analytical studies.

[Incidence of cardiovascular events in giant cell arteritis: preliminary results of a prospective double cohort study (GRACG)]. / Incidence des accidents cardiovasculaires au cours de la maladie de Horton: résultats préliminaires de l'étude prospective en double cohorte GRACG.

UNLABELLED: Giant cell arteritis is the most frequent vasculitis. Cardiovascular events such as cerebrovascular accident or ischemic heart disease may occur in patients with giant cell arteritis. However, their real incidence, as well as their relative risk compared to the general population, remains unknown. PURPOSE: To assess in a prospective, double cohort study, the incidence of cardiovascular events in giant cell arteritis patients compared to controls, after controlling for cardiovascular risk factors. PATIENTS AND METHODS: We included on predefined criteria 432 newly diagnosed patients with giant cell arteritis, each assigned to sex- and age-matched controls randomly selected from the general population. Cardiovascular risk factors (high-blood pressure, diabetes, smoking, hypercholesterolemia and preexisting peripheral vascular disease) were collected at inclusion. During the 24-month follow-up, all cardiovascular events were collected. After stratification for cardiovascular risk factors, a log-rank test was performed to compare cases and controls. A parametric survival model was used for multivariate analysis. RESULTS: Cardiovascular events all combined were significantly increased in patients with giant cell arteritis (RR = 2.15 [1.21-3.81], P = 0.009), and were mainly associated with age (P = 0.0001), past history of cardiovascular disease (P = 0.023) but also with giant cell arteritis (P = 0.009). However, each subset of cerebrovascular accident (RR = 2.42 [0.84-7]) or ischemic heart disease (RR = 1.67 [0.72-3.89]) increased but did not significantly. CONCLUSION: Cardiovascular events incidence is increased in patients with giant cell arteritis, and prescription of preventive antiagregant treatment may be discussed.

Vascular expression of annexin A2 in lupus nephritis.

AIMS: To evaluate vascular expression of annexin A2 (ANXA2) and its subunit S100A10 in lupus nephritis (LN). METHODS: The present histological study included 14 patients with LN and 11 controls (patients with non-lupus kidney diseases). Kidney biopsies from patients with lupus were scored for lupus glomerulonephritis (according to the International Society of Nephrology/Renal Pathology Society 2003 classification) and vascular lesions (such as microthrombi and antiphospholipid syndrome nephropathy (APSN)). ANXA2 and S100A10 expression in glomerular and peritubular capillaries was evaluated by immunohistochemistry on tissue sections. The staining intensity score ranged from 0 (no expression) to 4 (intense expression). RESULTS: In patients with LN, the median age (range) at first kidney biopsy was 36 (18-49). Vascular lesions were observed in six patients (including two with APSN). We observed intense expression of ANXA2 in glomerular and peritubular capillaries while expression of S100A10 was weaker. However, one of the patients with APSN showed strong S100A10 expression. Patients with LN and controls differed significantly in terms of S100A10 expression in peritubular capillaries. We also observed a statistical difference between patients who had LN with renal vascular lesions and those without renal vascular lesions in terms of ANXA2 expression in peritubular capillaries. CONCLUSIONS: The presence of vascular lesions in LN appears to be associated with significant differences in the vascular expression of ANXA2. Vascular expression of ANXA2 was somewhat higher in LN. Vascular expression of S100A10 was somewhat lower in LN (except one of the two patients with APSN). Further studies of ANXA2's putative value as a biomarker of active LN or of vascular lesions in LN are required.

Community-acquired bacteraemic pneumococcal pneumonia in adults: effect of diminished penicillin susceptibility on clinical outcome.

Pneumococcal pneumonia remains a common disease with a high mortality rate. Between 1995 and 2000, we prospectively analyzed 95 consecutive adult cases of community-acquired bacteraemic pneumococcal pneumonia treated in a single centre. The incidence of pneumococcal resistance to penicillin increased from 19 to 50% during the study period. Multivariate analysis showed that only age and recent hospitalization were independently associated with fatal outcome. The proportion of penicillin-resistant strains was slightly but not significantly higher among patients who died before the fourth hospital day than among those who died later. Patients who died before D4 were more likely to have a recent history of hospitalization, cancer and/or chemotherapy. It thus appears that infection by a resistant pneumococcal strain is not in itself a gravity factor in this setting, but that their acquisition is associated with pejorative clinical features.

[Statistics and humanities]. / Des chiffres et des lettres...

PURPOSE: This paper introduces a series of short articles focusing on methodological tools in clinical research, and describes some of the relations existing between medical practice and clinical research. STATE OF THE ART AND MAIN POINTS: The nature of the differences between statistical, epidemiological, and clinical uncertainty, and the lack of knowledge regarding relations between in vivo and in vitro phenomenon are explored. Also, notions of precision of numbers and validity of quantification are discussed and compared with the validity of narrative description of a pathological process, such as it is supposed to actually occur. PERSPECTIVES AND PROJETS: Intrinsic limitations of analytical and observational methods being explained, the usefulness of these same methods in the understanding of a disease or the evaluation of a therapy will be progressively described in more details.

[Aetiological spectrum of hyperferritinemia]. / Spectre étiologique des hyperferritinémies.

UNLABELLED: Serum ferritin levels may be increased in many conditions: renal diseases, liver diseases, human immunodeficiency virus infection. The purpose of this study was to assess the aetiological spectrum of high serum ferritin levels in a 1200-bed university hospital, to compare our results with the data already published and to assess a potential association between aetiology and ferritin levels. PATIENTS AND METHODS: Patients with a serum ferritin level higher than 600 microg/l were retrospectively included between 15 November 2003 and 15 January 2004, and their medical records were reviewed. RESULTS: Ninety-eight patients (38 women and 60 men; median age: 59,5 years [19-92]) were recruited in departments of hepatology and gastroenterology (22%), haematology (14%) and internal medicine (18%). Diagnosis performed were: non-HIV systemic infections (23,8%), haematological diseases (16,1%), alcoholism (11,2%) and malignancies (9,8%). Dialysed chronic renal failure, liver diseases, haemochromatosis and systemic inflammatory diseases counted for 4.2 to 5.2% of cases. Serum ferritin level lied between 600 and 1000 microg/l for 50 patients, between 1000 and 1500 microg/l for 24, and over 1500 microg/l for 24. There was no significant difference between the three groups as regards the etiological distribution. DISCUSSION: In our study, chronic renal failure was not a major cause of high ferritin level: this is probably due to the current use of erythropoietin, which has decreased the use of blood transfusions. The two major aetiology of hyperferritinemia were non-HIV infections and malignancies.

Prophylactic antibiotics in treatment of severe acute alcoholic pancreatitis.

Infectious complications currently account for 80% of deaths from acute pancreatitis. The aim of this study was to evaluate the necessity for prophylactic antibiotics in patients with severe acute pancreatitis. Twenty-three consecutive patients suffering from acute alcoholic pancreatitis with computed tomography demonstrating two or more fluid collections were randomly assigned to one of two groups receiving either nonantibiotic treatment or prophylactic antibiotics (ceftazidime, amikacine, and metronidazole for 10 days). Sepsis was always diagnosed by positive cultures. Seven episodes of severe sepsis occurred (pancreatic infection and septic shock) in the nonantibiotic group, and no infection occurred in the prophylactic antibiotic group (p < 0.03). In conclusion, the use of prophylactic antibiotics in severe alcoholic acute pancreatitis significantly reduces the incidence of severe infection.

Pharmacokinetics and ascitic fluid penetration of piperacillin in cirrhosis.

The pharmacokinetics of piperacillin were evaluated in seven healthy volunteers, eight cirrhotic patients without ascites and 11 cirrhotic patients with sterile ascites after a single 15-min intravenous infusion of 4 g of the drug. In ascitic patients, piperacillin rapidly entered the peritoneal fluid. Peritoneal concentrations were higher than 10 mg/l from 0.5 to 8 h after the infusion. Disappearance rate of piperacillin was slower in the ascitic fluid than in plasma. The plasma half life of piperacillin was more prolonged in cirrhotic patients that in control subjects. This difference was more marked in ascitic patients for whom half life was twice as high as in volunteers (1.95 versus 0.91 h; P less than 0.01).

Utility of blood cultures in community-acquired pneumonia requiring hospitalization: influence of antibiotic treatment before admission.

It has been previously shown that antibiotics given before hospitalization significantly reduce the proportion of positive blood cultures in community-acquired pneumonia (CAP). The aim of this prospective study was to compare the utility and cost-benefits of blood cultures in patients, hospitalized for moderate CAP, who had or had not received antibiotic therapy prior to admission. During 1 year, 53 patients were included and separated into two groups: group 1 patients had not received antibiotic treatment prior to admission (n = 30), whereas group 2 patients had been treated with antibiotics (n = 23). Within the first 48 hours, a set of blood cultures was collected if the body temperature was higher than 38.5 degrees C or in the case of shaking chills. A total of 136 blood cultures was collected; 74 in group 1 and 62 in group 2. Bacteraemia was significantly more frequent in group 1 than in group 2, 5/30 patients vs. 0/23, respectively (P < 0.05). The cost of negative blood cultures was valued at 13,939.2 FF in group 1 and 13,164.8 FF in group 2, respectively 464.6 +/- 244.3 FF and 569.3 +/- 233.4 FF per patient (n.s.). Moreover, blood cultures were the method of diagnosis in only one of the five patients with bacteraemia and in no case did a positive blood-culture result influence the initial therapeutic regime. Thus, our results suggest a reduced clinical utility and cost-benefit of blood cultures in patients hospitalized for moderate CAP who have received an antibiotic treatment prior to admission.

[Hepatic brucelloma (pseudotumoral brucellar caseous necrosis of the liver). Study of a case and review of the literature]. / Brucellome hépatique. (Nécrose caséeuse brucellienne hépatique pseudo-tumorale). Etude d'un cas et revue de la littérature.

We report the case of a 43 year-old Portuguese woman, hospitalized for long-standing fever, fatigue and weight-loss. Biologic investigation demonstrated anicteric cholestasis. Abdominal plain film showed a single hepatic calcification; computerized tomography and ultrasonography of the liver led to the discovery of a large mass, centered by the calcification. C. T.-guided biopsy showed caseiform necrosis, surrounded by histiocytic and lymphocytic cells. Brucella agglutination tests were negative at the beginning of the illness but became positive secondarily. The germ was not isolated from the hepatic fragment. The melitine intradermo-reaction was positive. Outcome was rapidly favorable with antibiotic treatment. Analysis of the 14 previously published cases showed that the most constant features were the hepatic calcifications and the epidemiologic context.

[Clinical and pharmacokinetic study of pefloxacin in spontaneous ascitic fluid infections]. / Etude clinique et pharmacocinétique de la péfloxacine dans les infections spontanées du liquide d'ascite.

Ten patients with spontaneous ascitic fluid infections received intravenously 400 mg of pefloxacin for pharmacokinetic evaluation of the drug and its diffusion into peritoneal space. The patients were then treated with oral pefloxacin (400 mg every 36 h except for icteric patients: 48 h) during 21 days. Total body clearance was decreased (0.66 +/- 0.16 ml/min/kg) and elimination half life was increased as compared to that observed in normal subject (28.2 +/- 7.6 h), the longest half-lives being observed in the cases with the most severe alteration of hepatic function. Peritoneal concentrations were higher than 1 microgram/ml (i.e. exceeding the minimal inhibitory concentrations for most of the bacterial species involved in ascitic fluid infections) from the first half-hour after infusion to at least 36 hours. 9 of the 10 cases were cured. Pefloxacin provided a well spaced rythm of administration is a suitable antibacterial drug for ascitic fluid infections in cirrhotic patients with two advantages: its effectiveness against Enterobacteriaceae and an oral administration.

[Antibiotic-associated pseudomembranous colitis: retrospective study of 48 cases diagnosed by colonoscopy]. / Les colites pseudomembraneuses associées à une antibiothérapie: étude rétrospective de 48 cas diagnostiqués par coloscopie.

Pseudomembranous colitis (PMC) is a rare but potentially severe complication of antibiotic treatment, which is characterized by the proliferation of the bacterium Clostridium difficile in the colon. In this retrospective study, 48 cases of endoscopically confirmed PMC were included. The following variables were analysed: characteristics of the patients, antibiotics, clinical, biological and endoscopic features of PMC and its treatment. The antibiotic treatment was often ambulatory (83 per cent) for a broncho-pulmonary infection (42 per cent). In 90 per cent of the cases, the treatment included a -lactam, frequently amoxicillin with clavulanic acid, and in 25 per cent of the cases, a fluoroquinolone. The PMC generally occurred after more than 4 days of treatment and was associated with diarrhoea, abdominal pain, fever and rarely vomiting (23 per cent). The complications were hypokalaemia (37 per cent), renal failure (27 per cent) and/or hypoproteinaemia (50 per cent). Pseumembranes were found between the rectum and the left angle of the colon. All patients recovered after one week of oral treatment with metronidazole and/or vancomycin, often in association with Saccharomyces boulardii.

[Role of biliary intubation in the diagnosis of acute pancreatitis without known etiology]. / Place du tubage biliaire dans le diagnostic des pancréatites aiguës sans étiologie retrouvée.

Biliary tubage, is interesting in the aetiological research of acute pancreatitis, when the origin is unknown after anamnesis, clinical examination, abdominal ultrasonographic studies and retrograde cholangiography. The sludge is the aetiology fond in 40% of the cases. Microscopic crystals are either cholesterol monohydrate, either calcium bilirubinate, or calcium carbonate microspheroliths. Biliary microscopic crystals drive the patients to the cholecystectomy to prevent acute pancreatitis relapses.