Relationships of immunoglobulins E and G sensitization to respiratory function in dairy farmers.

An impairment of respiratory function has been demonstrated in dairy farmers. The objective of this study was to evaluate the relationship of allergy to respiratory function in dairy farmers in a longitudinal study conducted in the Doubs (France). A cohort of male dairy farmers constituted in 1990 was re-evalued in 1995. Subjects completed a medical and occupational questionnaire, and a spirometry test in both 1990 and 1995, in 1995 they were also subjected to immunological tests. Relationships between immunological variables and respiratory function were studied by a multiple linear regression model adjusted for age, smoking status, respiratory symptoms, altitude and occupational exposure. Amongst the 394 subjects of the initial cohort, 330 were included in the longitudinal study and 320 had immunological tests. Log immunoglobulin (Ig) E was negatively correlated with the 1995 respiratory function parameters (p<0.05 for forced expiratory volume in one second (FEV1) and FEV1/vital capacity (VC). Immunoglobulin (Ig) G response to Aspergillus fumigatus detected by enzyme-linked immunosorbent assay (ELISA) was negatively correlated to 1995 respiratory function parameters (VC: p<0.01; FEV1: p<0.001; FEV1/VC: p<0.01). There was a positive relationship between IgG antibodies against Aspergillus fumigatus and the mean annual decline in FEV1 (p<0.01) and FEV1/VC (p<0.01). To conclude, allergy may play a role in the impairment of respiratory function in dairy farmers of the Doubs and sensitization to Aspergillus fumigatus seems to constitute an independent risk factor for the development of airflow obstruction in this occupational setting.

Dialysis adequacy and homocyst(e)ine concentrations in peritoneal dialysis patients.

INTRODUCTION: Determinants of hyperhomocysteinaemia in peritoneal dialysis patients have been recently reported but there is still conflicting data on the influence of dialysis adequacy on homocysteine (Hcy). METHODS: We studied 46 consecutive new continuous ambulatory peritoneal dialysis (CAPD) patients to determine the variation of Hcy before and 1 and 6 months after dialysis. The variation in Hcy was analysed with respect to dialysis adequacy, factors known to influence its metabolism, and Hcy peritoneal clearance. RESULTS: Hcy was 31.9+/-9 micromol/l before dialysis. It was significantly higher before dialysis than 1 month after the onset of PD (31.9+/-9 micromol/l vs 23.2+/-6.9 micromol/l, P < 0.0005). Weekly PD Hcy clearance was 14.3+/-5.4 1. There was no relationship between pre-dialysis Hcy and 1 month post-dialysis Hcy (r=0.176, P=0.15). There was a strong relationship between PD Hcy clearance and both PD creatinine clearance (r=0.502, P<0.005) and Kt/V (r=0.42, P<0.005). There was no relationship between Hcy and PD creatinine clearance (r= -0.221, P=0.11). In contrast, the decrease in tHcy at 1 month was related to PD Hcy clearance (r=0.487, P<0.01), to PD creatinine clearance (r= 0.349, P<0.02) and to Kt/V (r=0.32, P<0.02). Multivariate analysis confirmed the relationship between the decrease in Hcy and dialysis adequacy. Eleven patients (24%) experienced arteriosclerotic complications. Fasting Hcy concentrations in this population were significantly higher before and 1 month-post-dialysis than in patients without cardiovascular complications. CONCLUSIONS: We observed a significant and prolonged reduction in Hcy concentrations by peritoneal dialysis in end-stage renal disease patients. The decrease in Hcy concentration was positively related to dialysis adequacy. This study suggests the possibility that dialysis adequacy may influence arteriosclerotic outcomes through an Hcy-lowering effect.

Prevalence, determinants, and clinical significance of hyperhomocyst(e)inaemia in renal-transplant recipients.

BACKGROUND: Previous studies have demonstrated that hyperhomocyst(e)inaemia is present in patients with impaired renal function and is correlated with cardiovascular disease. Because conflicting data are available on the prevalence, determinants, and clinical significance of hyperhomocyst(e)inaemia in renal-transplant recipients, we conducted the largest cross-sectional study on homocysteine determinants and clinical correlates in renal transplant recipients. METHODS: Plasma homocyst(e)ine concentrations and factors known to influence homocysteine metabolism were analysed in 224 renal transplant recipients. Atherosclerotic complications were evaluated with respect to plasma homocysteine concentrations. RESULTS: Mean plasma homocyst(e)ine was 21.3+/-9.7 micromol/l. After adjusting for age, gender, transplant duration, and creatinine clearance, patients with and without cyclosporin A (CsA) had similar plasma homocyst(e)ine concentrations (16.9+/-5.9 micromol/l in CsA(+) patients vs 16.3+/-5.2 micromol/l in CsA(-) patients; P=0.3). We found a significant inverse relationship between plasma homocyst(e)ine and folate concentrations in both CsA(+) (r=-0.243; P<0.005) and CsA(-) (r=-0.396; P<0.05) patients. Patients with a past history of cardiovascular events had higher plasma homocyst(e)ine concentrations (25.2+/-11.7 mmol/l vs 20.5+/-8.9 mmol/l; P<0.005). CONCLUSION: Homocyst(e)inaemia is closely related to renal function and folate concentration in renal-transplant recipients. CsA does not seem to have direct effects on homocysteine metabolism. Hyperhomocyst(e)inaemia is associated with cardiovascular disease in renal-transplant recipients. Prospective placebo-controlled homocysteine-lowering therapy studies are required in this patient category.

Prevalence of asthma and respiratory symptoms in dairy farmers in the French province of the Doubs.

With the aim of determining whether dairy farming is associated with an excess of asthma and respiratory symptoms, we compared the respiratory status in a sample of dairy farmers (n = 265) and a control group of nonexposed subjects (n = 149). The study protocol comprised a questionnaire, spirometry, and a bronchodilatation test (400 micrograms salbutamol powder), and an allergological evaluation: serum total IgE level, Phadiatop test, and skin prick tests (SPT) for seven inhalant allergens. Cumulative prevalences of self-reported asthma and of current asthma were respectively 5.3% and 1.5% in farmers, and respectively 3.4% and 1.3% in control subjects (both NS). Prevalences of all the respiratory symptoms studied were higher in farmers, with statistically significant differences after adjusting for age, sex, and smoking, for wheezing ever (OR: 2.7, p < 0.05), wheezing within the last year (OR: 5.2, p < 0.025), usual morning cough (OR: 5, p < 10(-)3), usual morning phlegm (OR: 11.3, p < 10(-)4), and chronic bronchitis (OR: 11.8, p < 0.01). The effect of exposure on these symptoms was more pronounced than, or of the same magnitude as that of smoking. Smoking and exposure had an additive effect except for chronic cough for which a positive interaction was observed (p = 0.05). Mean FEV1/VC (percentage of predicted) was statistically negatively correlated to dairy farming (p < 0.025) after adjusting for confounders. Bronchial obstruction was reversible in about 10% of subjects in both groups. In conclusion, this study mainly demonstrated an excess of respiratory symptoms in dairy farmers which is weak and nonsignificant for asthma, and high for cough, phlegm, and chronic bronchitis. It also suggested that the combined effect of farming and smoking was synergistic on chronic cough.

[Serum and salivary immunoglobins A in atopic dermatitis. Prospective and comparative case control study]. / Immunoglobulines A sériques et salivaires dans la dermatite atopique. Etude prospective et comparative témoins-malades.

UNLABELLED: IgA system has been poorly studied in patients with atopic dermatitis (AD). Previous studies have showed that a transient serum IgA deficiency in infancy could lead to atopic disease. In addition, decrease in salivary IgA has been demonstrated in patients with AD. The purpose of our work was to study the IgA system both in serum saliva in patient with AD. PATIENTS AND METHOD: We conducted a controlled prospective study from January 1994 to May 1996. 46 patients with AD and 52 healthy volunteers matched for sex and age were included. Atopic patients fulfilled at least three major and three minor features defined by Hanifin and Rajka. None above atopic criteria were present in the control group. Saliva was collected using a small cylinder of a cotton-wool-like substance (Salivette) kept in the buccal fold. Serum and saliva samples were assayed for IgA using standard nephelometric method and time-resolved immunofluorometric assay. Secretory IgA were assayed by a sandwich-type enzyme linked immunosorbent assay. Blood eosinophils and serum IgE were also evaluated. RESULTS: IgA and secretory IgA were detected in all serum and saliva collected. No statistically significant difference were observed in serum or in saliva for both IgA and secretory IgA between patients with AD and controls. As expected, blood eosinophils and serum IgE were significantly increased in patients with AD. DISCUSSION: None patients (atopic or control) exhibited IgA deficiency. Although no statistically significant, a trend to higher concentrations of serum and salivary IgA was observed in patients with AD suggesting a stimulation of mucosa-associated lymphoid tissue in these patients.

Hyperhomocyst(e)inemia in renal transplant recipients with and without cyclosporine.

Studies have demonstrated that hyperhomocyst(e)inemia is present in renal transplant recipients and is correlated with cardiovascular disease. It is still unclear whether hyperhomocyst(e)inemia observed in renal transplant recipients solely depends on the moderate reduction of renal function in these patients or if additional mechanisms are operative in this patient category. A recent study suggested that cyclosporine (CsA) increased plasma homocyst(e)ine concentration in interfering with folate-assisted remethylation of homocysteine. To confirm this hypothesis, we studied plasma homocyst(e)ine folic acid and cobalamin concentrations in 122 renal transplant recipients (104 on CsA and 18 not receiving CsA). After adjusting for age, gender, transplant duration and serum creatinine concentration, patients with and without CsA had similar plasma homocyst(e)ine concentrations (17.9 +/- 6.1 mumol/l in CsA(+)patients vs 17.1 +/- 5.6 mumol/l in CsA(-)patients; p = 0.3). Moreover, we found a significant inverse relationship between plasma homocyst(e)ine and folic acid concentrations in both CsA(+) (r = 0.218; p < 0.01) and CsA(-) (r = -0.678; p < 0.05) patients. Patients with a past history of cardiovascular incidents had higher plasma homocyst(e)ine concentrations than those without cardiovascular antecedent (20.5 +/- 7.8 mumol/l vs. 18.01 +/- 9.9 mumol/l; p < 0.05. To conclude: 1, We did not find any influence of CsA on plasma homocyst(e)ine concentrations. 2. We demonstrated that as in other patient category, plasma folic acid and homocyst(e)ine concentrations are significantly correlated in CsA(+) patients. 3. Homocyst(e)ine-lowering therapy would be prescribed in CsA(+) patients to allow correction of hyperhomocyst(e)inemia.

[Respective influence of occupational and personal factors on respiratory function in dairy farmers]. / Influence respective des facteurs professionnels et personnels sur la fonction respiratoire en milieu agricole de production laitière.

Occupational and individual factors influencing respiratory function were analysed in a sample of dairy farmers. The study protocol included a medical questionnaire, an occupational questionnaire, spirometry and allergological tests (skin prick tests for a panel of inhalant allergens, serum total IgE level and Phadiatop (CAP System). Two hundred and forty-five farmers were studied (140 men, 105 women with an average age of 45.9 (11.3) years, 35 were smokers, 27 ex-smokers and 183 non-smokers). A multiple linear regression model was used to analyse the correlations between respiratory function and the different independent variables. There was a statistically significant negative correlations between smoking (expressed in pack-years) and all the respiratory function parameters (p < 0.01). Respiratory function was significantly impaired in farmers working on traditional farms (p < 0.05 for VC and for FEV1), and the respiratory function values increased proportionally with the modernisation of the farms (notably using an artificial barn drying system for hay and a ventilation system for the cow byres). No significant relationship between respiratory function and quantitative indicators of exposure (size of farm, amount of livestock, quantity of hay handled during professional lifetime) or indicators of IgE-mediated allergy was observed. In conclusion, this study suggests that traditional work conditions in farms which have little mechanisation are, along with tobacco, the determining factors for the respiratory function impairment in dairy farmers.

[Value of the protein profile in unexplained inflammatory syndromes]. / Intérêt du profil protéique dans les syndromes inflammatoires inexpliqués.

UNLABELLED: The diagnosis of unexplained inflammatory syndromes requires many investigations which are commonly expensive, often invasive and must be repeated several times. A means for physicians to improve the diagnosis procedure would be to have new tests available to select the best diagnosis procedures. In order to test the value of the protein profile (PP) in the case of unexplained inflammatory syndromes, we prospectively studied 95 among 650 patients admitted in our unit for an inflammatory syndrome defined by a C Reactive Protein level > 2 mg/dL and a sedimentation rate > 30 mm, which remained unexplained after a 5 day hospitalization (49 men, 46 women; mean age: 62.9 +/- 12.3 years). PP has been considered as a useful test for the diagnosis in 21 cases (22%) having been definitively established by pathologic examination (42%), radiologic procedures (24%), endoscopy (19%), immunological tests (19%), and serological test (9.5%). The definitive diagnosis was a systemic disease in 12 cases, infection (four cases), malignancy (three cases), amyloidosis (one case) and occult intestinal bleeding (one case). CONCLUSION: Our data indicate that PP is a useful test for the diagnosis of unexplained inflammatory syndromes; its main utility is the disclosure of some specific biochemical syndromes available for better selecting the definitive diagnosis procedures.

Amino acids and ammonia in the cerebral cortex, the corpus striatum and the brain stem of the mouse prior to the onset and after a seizure induced by hyperbaric oxygen.

The contents of amino acids (AA) and ammonia (NH3) were measured in corpus striatum, brain stem and cerebral cortex of two strains of mice exposed to hyperbaric oxygen (HBO). Mice of the HBO-sensitive strain (CD1) were exposed to 600 kPa O2 for 24 min versus 90 min for mice of the normal C57 strain, so that 50% of the mice in both strains developed a generalized convulsion. In the cortex of exposed but unconvulsed (EXUN) C57 mice, the contents of taurine, glutamine and NH3 increased while that of GABA decreased when compared to control mice. In the CD1 mice, NH3 content was increased while that of Asp decreased. After a convulsion, NH3 was increased in both strains, the AA contents returned to normal in C57 but Asp remained low in CD1 mice. Somewhat similar changes occurred in the striatum except that NH3 levels were less affected while GABA ones were significantly decreased in the CD1 mice exposed to HBO, whether convulsed or not. In the EXUN brain stem, Asp and Glu contents decreased. These decreases were greater in C57 on a percentage basis than in CD1 mice. GABA content was decreased in the C57 strain. After a convulsion, Asp and Glu levels remained low and NH3 accumulated in CD1 whereas in C57 only the Glu level was decreased. The cortical and striatal changes may indicate a lesser GABA supply in C57 strain and some Asp release in CD1 strain. In the brain stem of both strains, Asp and Glu release is possible in addition to GABA in C57 strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum secretory IgA and secretory component in patients with non-cirrhotic alcoholic liver diseases.

Elevated levels of secretory IgA in serum have been demonstrated in several liver dysfunctions such as hepatic cytolysis and cholestasis. However, these possible alterations at an early stage of liver diseases have not yet been investigated. We studied a cohort of chronic alcoholic patients without cirrhosis in order to assess the changes in serum secretory IgA and other forms of secretory component, the split product of the polymeric Ig-receptor of epithelial cells. The possible diagnostic value of these measurements in the assessment of alcoholic disease was compared to that of serum gamma-glutamyl transpeptidase activity. Serum levels of secretory IgA and IgM and free secretory component, were quantified by an enzyme-linked immunosorbent assay in 71 patients with chronic alcoholic liver disease without cirrhosis and in 45 healthy controls. Patients were divided into two groups according to the severity of the liver abnormalities. In addition, the reversibility of serum secretory IgA, IgM and free secretory component abnormalities after alcohol withdrawal was evaluated in 15 patients. Serum levels of the three molecular forms of secretory component were significantly higher than those measured in control subjects, both in the whole population of patients and in the two groups of alcoholic patients without cirrhosis. In all groups, serum secretory IgA levels were correlated to free secretory component but not to total IgA levels. Serum secretory IgA levels were as discriminative as gammaglutamyl transferase activity in distinguishing between chronic alcoholic patients without cirrhosis and non-alcoholic subjects. The abnormalities of serum secretory IgA concentrations were reversible after alcohol withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prevalence of immediate allergy to respiratory allergens in fodder farmers in Doubs]. / Prévalence de l'allergie immédiate aux pneumallergènes chez les agriculteurs fourragers du Doubs.

The Doubs is a damp, semi-mountainous fodder farming department in which occupational respiratory diseases (including asthma) are common in farmers. We studied the prevalence of IgE-mediated allergy (total IgE, Phadiatop and skin prick tests) in a group of 265 exclusive dairy farmers of both sexes of the department and in a control group of non exposed, administrative workers living in the same area. Skin prick tests were: Dermatophagoides pteronyssinus, Acarus siro, cat hair, cow danders, grass pollens, betullacea pollens (trees from the East of France), and hay extracts from the Doubs. Total IgE were higher than 180 KUI/l in 26 (9.9%) farmers and in 15 (10.5%) controls (NS). Phadiatop was positive in 41 (15.7%) farmers and in 27 (19%) controls (NS). Prevalence of positive skin prick tests (at least one) in farmers and controls was respectively 36% and 40% (NS). Farmers were more frequently sensitized to hay extracts (OR = 1.7), cow danders (OR = 1.3) and less frequently to cat hair (OR = 0.63) than controls but the differences were not statistically significant. In conclusion, this study fails to give evidence of a risk of IgE-mediated allergy to work-related and other common inhalation allergens in dairy farmers the Doubs.

Changes in striatal and cortical amino acid and ammonia levels of rat brain after one hyperbaric oxygen-induced seizure.

Changes in amino acids (AA) and ammonia were investigated in the cerebral cortex and striatum of rats after the following conditions: 1) one hyperbaric oxygen (HBO)-induced seizure (6 ATA O2); 2) exposure to 6 ATA air; and 3) exposure to atmospheric pressure (no seizures in both latter groups). Exposure to 6 ATA air produced no change with respect to atmospheric pressure. After HBO seizure, AA levels (except for gamma-amino butyric acid, GABA, and glutamine), with respect to 6 ATA air levels, were altered in the striatum with a concomitant rise in ammonia (+70%) at variance with the cortex. These changes could be explained by increased oxidative deamination in the striatum. Decrease in taurine content (-66%) in the striatum, where HBO lipoperoxidation exists, suggests an alteration of glial function leading to blockade of uptake and loss of released products in interstitial fluid. This pattern of change recalls the one seen in ischemic conditions, but cannot be confirmed in the absence of measurements of extracellular amino acid levels under HBO conditions. The maintenance in the level of GABA would favor its role in controlling seizure. In the cortex, only a few AA levels decreased, along with a nonsignificant trend for ammonia to increase. The remaining abnormalities in the striatum, after the first HBO seizure, may explain the already known repetition of seizures in continuously exposed animals and are consistent with previous data on the important role of the striatum.

[Effects of the calcium-channel blocker diltiazem on gentamicin-induced nephrotoxicity in rats]. / Effets d'un inhibiteur des canaux calciques, le diltiazem sur la néphrotoxicité de la gentamicine chez le rat.

Injection of diltiazem (40 mg/kg/d) to gentamicin (75 mg/kg/d = G 75 or 100 mg/kg/d = G 100) treated rats enhances aminoglycoside-induced nephrotoxicity. As a result of this combination, acute renal failure becomes systematic and is often irreversible. The lesion is of tubular origin and is characterized by a large increase in the urinary N-acetyl-beta-D-glucosaminidase (u-NAG) activity and its NAG-B isoenzyme level. The phenomenon is twice as marked with G 75 (u-NAG x 6.8, NAG-B x 2.2) as with G 100 (u-NAG x 3.1, NAG-B x 1.1). The effect seems to be attenuated if diltiazem is administered as a preventive treatment or in drinking water. As well as its diuretic properties, diltiazem may aggravate the renal toxicity of gentamicin by reducing the proximal tubular availability of calcium. Diltiazem inhibits reabsorption and behaves like a non-competitive inhibitor of calcium. This deficiency favours the proximal tubular binding and the non-specific penetration of gentamicin in the cytosol and cellular organelles (microsomes, mitochondria). The tubular toxic symptoms which ensure (inactivation of membranaceous enzyme, reduction of microsomal protein synthesis and ATP level, decreased of solute reabsorptive flux) lead in turn to proximal tubular necrosis and acute renal failure.

Use of anti-collagenase properties of doxycycline in treatment of alpha 1-antitrypsin deficiency panniculitis.

Three patients (a 71-year-old man and 2 women, 73 and 50 years, respectively) with recurrent panniculitis associated with alpha 1-antitrypsin deficiency are presented. Because the concept of chronic and exaggerated inflammatory response in the patients with alpha 1-antitrypsin deficiency is based on the theory of protease-antiprotease imbalance, we suggest that tetracyclines will alleviate this condition. Indeed, tetracyclines were found to inhibit collagenase activity. The total remission of the condition in these 3 patients underlines for the first time the effects of doxycycline on a condition characterized by deficiency of the antiprotease system. A review of the 23 reported cases of panniculitis associated with alpha 1-antitrypsin deficiency is presented in table form.

[Neutrophilic leukocytosis of systemic or bacterial origin: discriminative C-reactive protein?]. / Polynucléoses neutrophiles d'origine systémique ou bactérienne: valeur discriminante de la C réactive protéine?

Neutrophilic leucocytosis is frequent in systemic diseases and often leads to confusion with infective diseases. A C-reactive protein (CRP) level of 100 mg/l or more has been claimed to indicate a bacterial infection in over 80% of the cases. The purpose of this study was to test the discriminative value of CRP in patients with neutrophilic leucocytosis of bacterial or systemic origin. Sixty patients presenting with an inflammatory syndrome with neutrophilia entered the study and were divided into 2 groups. Group I comprised 30 patients with Horton's disease (n = 9), systemic vasculitis (n = 6), deep cancer (n = 5), connective tissue disease (n = 4) or Still's disease (n = 4). Group II consisted on 30 patients with infective diseases: septicaemia (n = 13), bacterial pneumonia (n = 12), pyelonephritis (n = 4) or cholecystitis (n = 1). In both groups the number of neutrophils was higher than 12,000/cubic mm. Mean CRP values were lower in group I (75.3 +/- 70 mg/l) than in group II (153 +/- 61 mg/l) (P less than 0.01). With values above 100 mg/l the specificity and sensitivity of CRP for infection were 45% and 55% respectively; the positive predictive value of CRP was 66% and its negative predictive value 76%. Specificity rose to 65% with a CRP level higher than 150 mg/l, and 74% for a CRP level higher than 200 mg/l, but such values were also observed in 4 patients of group I.(ABSTRACT TRUNCATED AT 250 WORDS)

[Nephrotoxicity of the combination of cyclosporin and aminoglycoside in rats. Comparative study of gentamicin and amikacin]. / Néphrotoxicité de l'association ciclosporine-aminoside chez le rat. Etude comparative de la gentamicine et de l'amikacine.

The renal toxicity of combined administration of cyclosporin and aminoglycosides was evaluated in rats. Increasing doses of amikacin (A) or gentamicin (G) were injected alone or in association with cyclosporin (CS). Creatinine clearance rate, urinary N-acetyl-Beta-D-glucosaminidase (NAG) activity and NAG-B isoenzyme level were determined to evaluate glomerular or tubular dysfunctions. When given alone, high doses of aminoglycosides (100 mg/kg/day of G and 375 mg/kg/day of A) induced transient inhibition of glomerular filtration rate. The concomitant administration of CS caused severe acute renal failures with 50 mg/kg/day of G and only with 375 mg/kg/day of A. With equal doses of G, urinary NAG excretion was seven times higher in association with CS than in monotherapy. In the same conditions, NAG activity was only doubled with A. A specific increased of NAG-B isoenzyme level occurred only during the most nephrotoxic association. This attest of a proximal tubular lesion, preliminary to glomerular dysfunction. The results of this study confirm the potent synergistic nephrotoxicity that CS exerts in combination with aminoglycosides. Nevertheless, the good tolerance of amikacin lead us to reconsider the principle of exclusion of such association in transplant recipients.

[Study of the bronchoalveolar lavage in ankylosing spondylarthritis]. / Etude du lavage broncho-alvéolaire au cours de la spondylarthrite ankylosante.

The study of the broncho-alveolar lavage (BAL) has been carried out in 15 consecutive (13 B27) ankylosing spondylarthritis (AS), compared to 17 test subjects. There is no modification of the number of cells, of the percentage of lymphocytes, of the CD4/CD8 ratio, of the beta-2-microglobulin or the conversion enzyme in the BAL liquid between the AS group and the test group. The IgA level of the BAL is lower and the IgA deposits in the bronchial mucosa are more frequent in the AS group (but not in a significant way). Unlike other inflammatory diseases, it seems that there is no subclinical alveolitis in the course of AS.

[Inhibition of the activity of urinary N-acetyl-beta-D-glucosaminidase (NAG) and its isoenzymes by amikacin]. / Inhibition de l'activité de la N-acétyl-beta-D-glucosaminidase (NAG) urinaire et de ses isoenzymes par l'amikacine.

Our study indicates that amikacin (AK) inhibited urinary N-acetyl-beta-D-glucosaminidase (NAG) activity. In vivo and in vitro experiments showed significant increase of Michaelis constant of urinary NAG, in human and in rat, treated by amikacin. Our data indicate that the inhibition of amikacin on NAG and its isoenzymes was "apparently competitive" rather than competitive as reported by others. In the "apparently competitive" inhibition the amikacin-enzyme binding would be irreversible, including combined action of many hydrogen bonds which could have a strength like covalent bond.

[Recurrent rhabdomyolysis and deficiency of carnitine palmityl transferase. Evidence of the responsibility of a mutant in 2 brothers]. / Rhabdomyolyse récidivante et déficit en carnitine palmityl transférase. Preuve de la responsabilité d'un mutant chez 2 frères.

In two brothers who had been presenting since childhood with intermittent muscular attacks and myoglobinuria after sustained efforts, muscle carnitine palmityl transferase (CPT) activity was undetectable by the backward hydroxamate colorimetric method. Such a total deficiency could not easily fit in with the clinical features (normal muscular activity outside sustained efforts), with the normal results obtained at electromyography and with the moderate fatty overload detected at muscle biopsy. In order to elucidate these apparently discordant findings, another CPT measurement method, the forward optimized isotopic technique, was used. With this method, the catalytic activity of CPT can be measured, and enzyme inhibition by its substrate and the product of the reaction (palmityl CoA and palmitylcarnitine respectively) can be studied. The results showed that the catalytic activity of CPT was preserved in both patients, but the enzyme was abnormally sensitive to inhibitors. These 2 cases tend to demonstrate the existence of a mutant carnitine palmityl transferase.