Catechin in the Mediterranean diet: vegetable, fruit or wine?

The aim of this study was to determine which type of diet contributes most to plasma concentration of (+)-catechin, a naturally occurring antioxidant flavonoid. Consecutive subjects (n=180) were screened. A blood sample was collected after a fasting period and (+)-catechin measurement in plasma was performed by high-performance liquid chromatography (HPLC) method using fluorescence detection. Dietary consumption of the last evening meal was assessed by a dietary recall method. Taking fruit, vegetable and wine consumption into account, four types of diet were identified. After adjustment for confounding factors, concentration of (+)-catechin in plasma was three-fold higher in diet with fruit and vegetable but without wine (449.5 microg/l), and four-fold higher in diet with wine but without vegetable and fruit (598.5 microg/l) in comparison to diet without fruit, vegetable and wine (131.6 microg/l). When the consumption of vegetable, fruit and wine was combined, the concentration was the highest (637.1 microg/l) (P<0. 001). Vegetable, fruit and wine were the major determinants of plasma (+)-catechin concentration (P<0.001). This study demonstrates that the highest plasma concentration of (+)-catechin was observed in subjects consuming fruit, vegetable and wine, and its antioxidant and antiaggregant activity could partly explain the relative protection against coronary heart disease (CHD).

Levels of flavan-3-ols in French wines.

French wines are abundant sources of phenolic compounds. The content of several catechins, i.e., (+)-catechin, (-)-epicatechin, dimers B1, B2, B3, and B4, trimers C1, and trimer 2 (T2), of 160 French wines was determined by HPLC with UV detection. Red wines (n = 95) were found to have high levels of catechins, ranging from 32.8 to 209.8 mg/L (mean concentration 114.5 mg/L) for (+)-catechin, from 22.1 to 130.7 mg/L (mean concentration 75.7 mg/L) for (-)-epicatechin, from 7.8 to 39.1 mg/L (mean concentration 25.4 mg/L) for B1, from 18.3 to 93 mg/L (mean concentration 47.4 mg/L) for B2, from 21.4 to 215.6 mg/L (mean concentration 119.6 mg/L) for B3, from 20.2 to 107.2 mg/L (mean concentration 81.9 mg/l) for B4, from 8.6 to 36.9 mg/L (mean concentration 26.3 mg/L) for C1, and from 26.7 to 79.3 mg/L (mean concentration 67.1 mg/L) for T2. White and rosé wines (n = 57 and n = 8) were found to have low levels of (+)-catechin (mean concentrations 9.8 and 10.6 mg/L, respectively) and (-)-epicatechin (mean concentrations 5.3 and 6.5 mg/L, respectively). These data provide a basis for the epidemiological evaluation of catechin intake by the consumption of French wine.

High-performance liquid chromatography coupled with fluorescence detection for the determination of trans-astringin in wine.

In this study a high-performance liquid chromatography (HPLC) method was developed for the determination of trans-astringin in wine using fluorescence detection. This is the first time the occurrence of trans-astringin has been reported in wine. The method allows analysis of both red and white wine samples with no prior treatment. The quantification threshold is 0.03 mg/l. Levels of trans-astringin in the French wines analyzed ranged from 0.09 mg/l to 0.29 mg/l. The reproducibility of the method was measured and the CV was less than 4.8% for both red and white wines.

Comparison of (+)-catechin determination in human plasma by high-performance liquid chromatography with two types of detection: fluorescence and ultraviolet.

In this study we developed a high-performance liquid chromatography (HPLC) method for the determination of (+)-catechin in human plasma, using both fluorescence and UV detection. Sample preparation involved precipitation of plasma proteins using acetonitrile, followed by direct injection into the HPLC system using both types of detection. Validation of accuracy and precision were satisfactory for both within- and between-batch assays. For fluorescence detection, coefficients of variation were less than 6.47% and mean relative errors were within +/-4.8%. The average recovery was 85.31%. The limit of detection and quantification were 5 ng/ml and 40 ng/ml, respectively. Ultraviolet detection was also used but appeared less sensitive and selective than fluorescence detection. This new method provides a simple, accurate, precise and specific method for the determination for (+)-catechin in plasma.

Macroscopic shape of, and lamellar distribution within, the upper limb shafts, allowing inferences about mechanical properties.

Collagen orientation maps were determined for the long bones of the upper forelimb (humerus, ulna, radius) using previously described techniques. All three bones had characteristic, non-random patterns of collagen fibre orientation. In the humerus, transverse collagen predominated in the medial and posterior cortices proximally and in the anterior and posterior cortices at the mid diaphysis. In the distal radius, the medial and anterior cortices contained mostly transverse collagen. In the proximal ulna, transverse collagen was found in the anterior and anterolateral cortices. These findings may be correlated to the distribution of bending forces that may be operative in these bones.

Orientation of collagen in human tibial and fibular shaft and possible correlation with mechanical properties.

The pattern of collagen orientation in two human tibiae and fibulae was studied. Serial 100 microns plane parallel cross-sections at 1 cm intervals at the same level in tibia and fibula were cut using an annular blade saw. Distribution of transversely oriented collagen was mapped using circularly polarized light and an image analyzing computer. In both the tibia and fibula the pattern of collagen orientation is characteristic, which may be related to the distribution of the bending forces normally operative in these bones.

On the structural symmetry of human femurs.

The distribution of transverse and longitudinal lamellae from osteons and interstitial bone of the two femurs from a woman aged between 25 and 30 was investigated. Exactly plane parallel cross-sections (100 micron) were prepared from the upper, middle and lower thirds of the two bones. The distributions of transverse and longitudinal lamellae was determined for both osteonic and interstitial bone, using circularly polarised light. The results show that (a) as in the male femur, the transverse and longitudinal lamellae in these female femurs have a characteristic rotational distribution along the shaft consistent with the distribution of the bending strains normally operative in bone; and (b) the rotational distribution of the two types of lamellae is slightly asymmetrical in the two female bones, probably because of imperfectly symmetrical use of the lower limbs.

Micro-biomechanics vs macro-biomechanics in cortical bone. A micromechanical investigation of femurs deformed by bending.

Previous studies have shown that longitudinal and transverse lamellae in compact bone signal the presence of tensile and compressive forces, respectively. On this basis an investigation has been carried out to ascertain the distribution of lamellae in femoral shafts that have been deformed by bending. To do this, a series of undecalcified plane-parallel sections 100 microns thick were prepared, and the proportion of transversely oriented collagen and crystallites in the lamellae was measured, using circularly polarized light as an illuminating source and a Quantimet 720 image-analyzing computer. It has been concluded that the distribution of the two types of lamellae is in accordance with the need to compensate for the deformity produced by the bending of the bones, and that an obvious relationship exists between the macroscopic features of the femurs and their modified microscopic structures.

Distribution of lamellae in human femoral shafts deformed by bending with inferences on mechanical properties.

On the basis of previous investigations indicating that the distribution of osteonic and interstitial lamellae in a normal femur depends on its mechanical properties, a procedure has been devised to provide information on the distribution of lamellae in human femora diaphyses deformed by bending. To achieve this, exactly plane parallel cross sections, 100 micron thick, were prepared from the portion of maximum bending, using an annular blade microtome. An index of the distribution of longitudinal lamellae (whose fiber bundles and crystallites have a longitudinal course and withstand loading by tension) and transverse lamellae (whose fiber bundles and crystallites have a transverse course and withstand loading by compression) was determined using circularly polarized light as illuminating source and a Quantimet 720 image analyzing computer. The results show that, even in a pathologically deformed bone, both the microscopic structure of sections at the level of osteonic and interstitial lamellae, and their macroscopic shape may be governed by the distribution of the forces active in bone.

Bone-cement interface: a histological study of aseptic loosening in twelve prosthetic implants.

The histology of bone-cement interfaces was studied by using new fixation techniques that preserve the cement, as well as sectioning the samples without decalcification. This permits histological study of the unaltered morphology, and the precise topographical distribution of fibrous tissue, bone necrosis and cellular anomalies in relation to the cement. Twelve cases of implant loosening over an average 7 year follow-up period were examined. By dynamic studies with sequential fluorescent bone labelling it was possible to evaluate precisely the extent of bone damage after the application of cement. The characteristic findings were: fibrous tissue at the bone-cement interface; bone necrosis or reduced remodelling in proximity to the cement; away from the cement, normal bone remodelling is clearly demonstrated by fluorescent labelling.

The lymphocytic transformation test (L.T.T.) in the evaluation of intolerance in prosthetic implants.

A state of hypersensitivity to the metallic constituents of prosthetic implants can be determined by culturing the patients lymphocytes in vitro in a medium containing the appropriate concentration of salts of the metal. If in these circumstances the lymphocytes proliferate, the patient is hypersensitive. Chromium, cobalt and nickel salts can produce such mitosis only in the lymphocytes of hypersensitive patients; the same test produces no such reaction in control subjects. This hypersensitivity can cause delayed loosening of the prosthesis. The lymphocyte transformation test (L.T.T.) is therefore a very useful preoperative measure in detecting patients who are allergic to these metals and so enables the surgeon to choose the right implant.

[Kinetics of cellular adhesion to different materials used in implants]. / Cinetica di adesione cellulare a differenti materiali usati in implantologia.

The authors expose their observations about the kinetics of cell adesion on two materials used as implants in orthopaedic surgery, AISI, 316 L steel and passivated titanium. The kinetics of cell attachment have been compared: an initial rapid increase of bound radioactivity was observed on passivated titanium (in 5 - 30 min) and after this rapid reaction the number of attached cells increased only slowly, during the following 30 min. After incubation of 90 min, almost all cells became attached. Kinetic of BHK cell attachment on AISI 316 L differs significantly: almost all added cells were attached in 90 min but the rapid increase of attachment is observed only during the first 30 min. These observations are important for the comprension of adhesion mechanisms and characterize the properties of biocompatibility of implant materials.