The chemical biomarkers C2C, Coll2-1, and Coll2-1NO2 provide complementary information on type II collagen catabolism in healthy and osteoarthritic mice.

OBJECTIVE: Compared with wild-type (WT) mice, biglycan/fibromodulin double-deficient mice develop severe knee osteoarthritis. We undertook this study to compare type II collagen catabolism in the 2 genotypes and to compare the usefulness of 3 biomarkers of collagen degradation (C2C [also known as Col2-3/4C(long mono)] as well as the peptide Coll2-1 and its nitrated form, Coll2-1NO2) for evaluating collagen catabolism in vivo. METHODS: In 15 WT mice and 15 biglycan/fibromodulin double-deficient mice, we determined serum levels of C2C at ages 66 and 141 days, and we determined serum levels of Coll2-1 and Coll2-1NO2 at ages 49, 81, 95, and 141 days. Expression of the biomarkers in knee sections was examined using immunohistochemistry. RESULTS: The mean concentrations of C2C and Coll2-1 were higher in biglycan/fibromodulin double-deficient mice at all time points. For C2C and Coll2-1, the ratio of the serum concentration in biglycan/fibromodulin double-deficient mice to that in WT mice (the double-deficient:WT ratio) was constant over time and was approximately 1.63 and approximately 1.15, respectively. In contrast, the double-deficient:WT ratio for Coll2-1NO2 varied and, depending on age, was >1 or <1. No significant correlation was found between the expression of the different biomarkers, except for a weak, negative correlation between Coll2-1NO2 and C2C. In both genotypes, antibodies to each biomarker labeled some fibroblasts in the tendons and menisci as well as chondrocytes above the tidemark in articular cartilage. Growth plates were unstained. For each biomarker, extracellular staining was limited to fibrocartilage areas in the tendons and menisci in all mice and was limited to some focal lesions of the cartilage in biglycan/fibromodulin double-deficient mice. CONCLUSION: The different double-deficient:WT ratios observed with C2C, Coll2-1, and Coll2-1NO2 in the absence of any correlation between the expression of the 3 biomarkers indicate that these biomarkers give complementary, rather than redundant, information about in vivo type II collagen catabolism.

Powdered milk micellar casein prevents oral colonization by Streptococcus sobrinus and dental caries in rats: a basis for the caries-protective effect of dairy products.

Three animal studies were performed to investigate the influence of the macromolecular structure of milk casein on caries incidence and the possible ecological changes of the oral microbiota by such casein fractions. Towards this end, rats were infected with mixed bacterial suspensions of Streptococcus sobrinus OMZ 176 and Actinomyces viscosus Ny1. Various milk protein fractions were incorporated into carefully balanced powdered cariogenic diets to constitute the sole major protein component. Diets containing micellar casein had a pronounced and highly significant effect on almost all clinical and microbiological parameters examined. Both the formation of advanced dentinal fissure (B) and smooth surface (E) caries lesions was inhibited by diets containing micellar casein; this caries-inhibiting effect appeared to be due mainly to modifications within the plaque microbiota. The proportion of S. sobrinus in the oral cavity of rats was reduced (73-80%) by micellar casein-containing preparations, whereas the A. viscosus population was increased. Both these microbiological parameters were always negatively correlated. This appears to be the first example of a food component other than dietary sugars, selectively modifying the composition of the dental plaque microbiota of rats in such a way as to reduce its pathogenic potential. It also demonstrates the importance of establishing a molecular basis for the role of food components, which prove to be beneficial to oral health.

Modulation of nonspecific mechanisms of defense by lactic acid bacteria: effective dose.

The purpose of this study was to determine the effect of a fermented milk product containing Lactobacillus johnsonii La1 (formerly known as Lactobacillus acidophilus La1) on the phagocytic activity of peripheral blood leukocytes in healthy adult volunteers. Furthermore, we sought to define the effective doses of the bacteria, examine the effect on respiratory burst activity, and, finally, examine the contribution made by the starter culture to the biological effects. Volunteers were randomly distributed among three groups; each subject received one pot (150 ml) of fermented milk each day for 3 wk. The first two groups received a freshly prepared product fermented by Streptococcus thermophilus (group A) alone or S. thermophilus and 10(7) cfu/ml L. johnsonii La1 (group B). Group C received a product stored for a period of 21 to 28 d and that contained S. thermophilus and 10(6) cfu/ml of L. johnsonii La1. Ingestion of L. johnsonii La1 did not significantly increase fecal lactobacilli counts. However, L. johnsonii La1 was able to survive intestinal transit and was only recovered from the feces of the volunteers of groups B and C. The fermented base alone showed a weak effect on respiratory burst but not on phagocytic activity. However, the product containing 10(7) cfu/ml L. johnsonii La1 significantly enhanced both functions. The product containing 10(6) cfu/ml of L. johnsonii La1 had no significant effect on either function. These results suggest that fecal persistence may not necessarily reflect in vivo colonization and may not be a prerequisite for all forms of immune reactivity.

Urinary excretion of 3-methyladenine after consumption of fish containing high levels of dimethylamine.

The urinary excretion of the DNA alkylation product, 3-methyladenine (3-MeAde), was measured in human volunteers who were on controlled diets and consumed fresh fish, or frozen-stored fish that contained 50-fold higher levels of dimethylamine (DMA), with or without ingested nitrate. DMA potentially could react with nitrosating agents in the diet or within the body, and produce the potent carcinogen N-nitrosodimethylamine (NDMA), which can then react with DNA to form several adducts including 3-MeAde. Our findings show that there was no increase in urinary levels of 3-MeAde after consumption of fish preserved by frozen storage relative to levels after consumption of fresh fish. Furthermore, consumption of 225 mg sodium nitrate (equal to the nitrate content in a large glass of beet juice) at 1 h prior to consumption of the frozen-stored fish did not increase urinary 3-MeAde levels as would be expected if nitrate enhanced endogenous nitrosation of DMA. In contrast, urinary excretion of 3-MeAde from a volunteer who was a moderate cigarette smoker (11 cigarettes per day) was approximately 3- to 8-fold higher than dietary 3-MeAde intake. These findings indicate that consumption of high levels of DMA in fish does not result in detectable levels of NDMA formation and genetic damage as measured by the urinary biomarker 3-MeAde.

Formation and differential removal of C-8 and N2-guanine adducts of the food carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline in the liver, kidney, and colorectum of the rat.

Chronic feeding of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in the diet results in tumor formation of the liver and colorectum, but does not induce tumorigenesis in the kidney of male Fischer-344 rats. The formation and rate of removal of DNA adducts were investigated in rats given an oral dose of IQ (20 mg/kg) to determine if adduct persistence affects the tissue susceptibility to IQ-induced tumorigenesis. Analysis of DNA adducts by 32P-postlabeling showed the formation of two 2'-deoxyguanosine (dG) adducts, N-(deoxyguanosin-8-yl)-2-amino-3-methylimidazo[4,5-f]quinoline (dG-C8-IQ) and 5-(deoxyguanosin-N2-yl)-amino-3-methylimidazo[4,5-f]quinoline (dG-N2-IQ) The pattern and distribution of these dG adducts were similar in all tissues; dG-C8-IQ and dG-N2-IQ accounted for approximately 70% and 15-20%, respectively, of the observed radioactivity. Maximal DNA binding was observed in liver (7.64 +/- 1.08 adducts per 10(7) bases) and in colorectum (1.08 +/- 0.22 adducts per 10(7) bases) 24 h following IQ treatment, while optimal binding appeared in kidney (2.41 +/- 0.47 adducts per 10(7) bases) 72 h after treatment. Greater than 50% of the dG-C8-IQ adduct was removed from DNA of liver and kidney within 1 week of treatment. In contrast, the dG-N2-IQ adduct persisted and was the principal lesion remaining in liver and kidney 4 weeks after treatment with IQ. There was no evidence for selective removal of either adduct in the colorectum over a 3 week period, and adduct removal appeared to be attributed to cell turnover and not due to excision repair processes. Therefore, the relative persistence of dG-C8-IQ and dG-N2-IQ adducts doses not appear to explain tissue susceptibility to IQ-induced neoplasia. The slow disappearance of IQ-DNA adducts suggests that adducts may accumulate during chronic exposure to IQ. Further investigations on DNA adduct formation and removal in animals chronically exposed to this carcinogen may help to explain the susceptibility of various organs to IQ-induced tumorigenesis.

Immunomodulation of human blood cells following the ingestion of lactic acid bacteria.

Because of the lack of data that convincingly show immunomodulatory properties of lactic acid bacteria in humans, a study was performed in which healthy volunteers were divided into two groups and given a fermented milk product supplemented with Lactobacillus acidophilus strain La1 or Bifidobacterium bifidum strain Bb 12 for 3 wk. Blood was sampled throughout the study to assess changes in lymphocyte subsets or leukocyte phagocytic activity following consumption of the fermented products. No modifications of lymphocyte subpopulations were detected. In contrast, phagocytosis of Escherichia coli sp. in vitro was enhanced after the administration of both fermented products. The increment in phagocytosis was coincident with fecal colonization by the lactic acid bacteria and persisted for 6 wk after ingestion of the fermented products. By this time, the fecal lactobacilli and bifidobacteria had returned to concentrations prior to consumption. Nonspecific, anti-infective mechanisms of defense can be enhanced by the ingestion of specific lactic acid bacteria strains. These strains can be used as nutritional supplements to improve the immune function of particular age groups, i.e., the neonate or the elderly, for which these functions are diminished.

Modulation of a specific humoral immune response and changes in intestinal flora mediated through fermented milk intake.

This study was undertaken to elucidate whether eating a fermented milk containing Lactobacillus acidophilus La1 and bifidobacteria could induce changes in intestinal flora and modulate the immune response in man. Volunteers consumed a fermented milk containing L. acidophilus La1 and bifidobacteria over a period of three weeks during which an attenuated Salmonella typhi Ty21a was administered to mimic an enteropathogenic infection. A control group ate no fermented foods but received the S. typhi Ty21a. Faecal flora analyses showed an increase in L. acidophilus and bifidobacterial counts during fermented milk intake. The specific serum IgA titre rise to S. typhi Ty21a in the test group was > 4-fold and significantly higher (P = 0.04) than in the control group. An increase in total serum IgA was also observed. These results indicate that lactic acid bacteria which can persist in the gastrointestinal tract can act as adjuvants to the humoral immune response.

Metabolism and pharmacokinetics of [14C]-deoxyfructosylserotonin creatinine sulfate administered orally and intravenously to rats and mice.

Deoxyfructosylserotonin (DFS) has been shown in in vitro tests to inhibit L-DOPA-oxidase and also to suppress the multiplication of Mycobacterium leprae. The possible therapeutic use of DFS makes necessary the study of its metabolic fate in animal models. Labelled [14C]-DFS was synthesized by condensation of serotonin and [14C]-glucose and administered per os or intravenously to rats and mice. After oral administration, some of the radioactivity transited through the intestinal tract to be excreted in feces (20-60% of the dose) and some was destroyed in the pH conditions of the intestine and further metabolized by the flora, producing 14CO2 in the expired air (10-40% of the dose). Radioactivity excreted in the urine amounted to 8-15% after 24 h. After intravenous administration, 60-90% of the dose had already been excreted in the urine after 8 h. Feces and CO2 accounted for 5-10% each. In the urine, for both routes of administration, beside DFS, half of the radioactivity corresponded to the glucuronide conjugate, while in the feces all the radioactivity found was unchanged DFS. Whole animal body autoradiography showed the presence of radioactivity in all the organs (1-2% of the dose) mainly resulting from the incorporation of labelled carbon from glucose and CO2. These results, obtained in healthy rats, demonstrate poor intestinal absorption of DFS (10% of the dose) and when it is absorbed, rapid urinary excretion. For its possible therapeutic use as an anti-leprosy drug in humans, derivatives with higher bioavailability must be attained.

Calcium absorption in man: some dosing recommendations.

The absorption of calcium involves a saturable (active) and a nonsaturable (passive) component. The work of several investigators indicates that an inverse relationship exists between calcium intake and absorption efficiency. Human calcium absorption data from the literature were analyzed using a model which included both an active and a passive absorption component. Simulations were provided to illustrate the suitability of this model, and another previously reported model, to fit the data and to estimate the absorption efficiency of calcium when using different dosing regimens. Comparisons of the values predicted in this study with some literature values are provided and some assumptions and potential limitations associated with the use of this method are discussed. The division of the daily dose into equal increments taken at equally spaced intervals over the course of the day is recommended as a useful procedure for increasing the absorption efficiency and efficacy of calcium.

Importance of oxidative polymorphism and levomepromazine treatment on the steady-state blood concentrations of clomipramine and its major metabolites.

The relationship between the debrisoquine oxidation status and the metabolism of clomipramine was studied in nine healthy volunteers (five rapid hydroxylators, three slow hydroxylators and one of intermediate status). The hydroxylation of clomipramine and demethylclomipramine were found to covary with that of debrisoquine, whereas demethylation of clomipramine seemed to be independent of the debrisoquine hydroxylation phenotype. The steady-state blood concentrations of clomipramine and its three main metabolites were measured in 122 depressed patients. Thirteen patients who concomitantly received a neuroleptic tended to have higher levels of demethylclomipramine and clomipramine, whereas the levels of the hydroxylated metabolites were hardly affected. Benzodiazepine co-administration did not modify the pharmacokinetics of clomipramine. The results suggest that benzodiazepines rather than levomepromazine should be used in depressed patients with anxiety and/or agitation in combination with the antidepressant treatment.

Plasma flupentixol concentrations and clinical response in acute schizophrenia.

Twenty-three acutely psychotic inpatients treated with flupentixol were included in the study. Steady-state plasma concentrations were compared with therapeutic outcome in a routine clinical setting. The threshold concentration for satisfactory antipsychotic effect appeared to be approximately 2 ng/ml. Controlled studies are needed to establish the existence and exact limits of a therapeutic window.

[Automatic design of a linear or logarithmic scale. Application to plotting of conversion scales]. / Dessin automatique d'une échelle linéaire ou logarithmique. Application au tracé d'échelles de conversion.

This flexible program permits automatic linear or logarithmic scaling between two limiting values set by the user. The software is in BASIC adapted for the Hewlett-Packard calculators HP-9845B and HP-85A.

A simple, automatic means of designing a conversion table for expressing laboratory results in the International System of Units (SI).

A simple, automatic means of designing a conversion table for expressing laboratory results in the international system of units (SI) is described. The increasing use of the international system of units for expressing the results of clinical chemistry and haematology sets doctors, biologists and paramedical workers the problem of converting the results from the previous confused system of units into the SI system. We propose a simple method for establishing a conversion scale from one system to the other, irrespective of the parameter. This is based on a Hewlett-Packard 9830A calculator equipped with a 9862A plotter. The BASIC language is used. Accordingly we have prepared conversion tables for the most commonly used parameters into the international system of units, on behalf of the Swiss Academy of Medical Sciences.