Immunodetection of lactosylated proteins as a useful tool to determine heat treatment in milk samples.

This paper reports the optimisation of a competitive immunoassay (ELISA) to detect lactosylated proteins in milk samples. The assay employs monoclonal antibodies for lactosylated proteins produced in our laboratory and requires no pre-treatment of the samples other than a dilution step. Monoclonal antibodies were fully characterised in terms of selectivity and cross-reactivity with structurally related molecules and used in a competitive assay format with lactosylated standard proteins (lactosylated ovalbumin). The detection limit for lactosylated ovalbumin was 0.015 microgram ml-1 and the working range was from 0.010 to 40 micrograms ml-1. The data obtained indicate that the ELISA developed is applicable to diluted milk samples and is able to distinguish between milk samples that have undergone different heat treatments (UHT and pasteurised milk).

Physiological cyclic variation of the myocardial integrated backscatter signal in athlete's heart.

BACKGROUND: Left ventricular hypertrophy which realizes in athlete's heart could create some problems of acoustic reflection related to the increase of myocytic and not-myocytic elements of the heart. The aim of the present study was to analyze the ultrasonic backscatter myocardial indexes both as peak end-diastolic signal intensity and as its cardiac-cyclic variation in athlete's heart, compared to healthy sedentary controls. METHODS: Two groups of ten subjects each, all males of mean age (31.6+/-3.5), and of comparable weight and height were analyzed: group (A) comprised ten cyclists of good professional level and group (C) included ten healthy subjects acting as controls. A 2D-color Doppler echocardiography with a digital echograph Agilent Technologies (AT) Sonos 5500 was carried out on all subjects in the study for the conventional analysis of the left ventricular mass and function. The ultrasonic myocardial integrated backscatter signal (IBS) was analyzed with an "Acoustic Densitometry" module implemented on an AT echograph. The signal was also sampled with a R.O.I. placed at interventricular septum and at posterior left ventricular wall level. The systo-diastolic variation of the backscatter was also considered as Cyclic Variation Index (CVIibs). RESULTS: The left ventricular mass was significantly higher in athletes in comparison with controls (LVMbs: A: 154.5+/-18.7; C: 101.4+/-12.4; p<0.001). The end diastolic IBS signal did not show significant statistical differences between the two groups. The CVIibs both at septum (A: 30.5+/-5.3; C: 27.2+/-7.3; p<0.002) and posterior wall level (A: 43.7+/-9.1; C: 40.7+/-9.1; p<0.001) though was comparable in both groups. CONCLUSION: The conclusions reached in the present study confirmed the physiology of the left ventricular hypertrophy of the athlete's heart evaluated with an ultrasonic integrated backscatter tissue characterization, in particular through the cyclic variation of integrated backscatter myocardial signal. This finding is probably the expression of a preserved intramural myocardial function in the athlete's heart despite the increase of left ventricular mass induced by physical training.

Umbilical blood flow and placental pathology.

The aim of the study was to establish whether or not placental morphostructural damage correlates with umbilical artery Doppler waveform and neonatal condition. To this end, seriated ultrasonographic monitoring, flowmeter tests on the cord artery and computerized cardiotocography were carried out in a population of 93 pregnant women in the second half of pregnancy. After birth placentas were subjected to macroscopic and microscopic examination. The Resistance Index showed a good correlation with placental vascular lesions, characterized by a distinct reduction in terminal villi and muscular wall arterioles. Two types of intrauterine growth retardation were discernible, the first of genetic origin with a low-profile growth curve and therefore not amenable to treatment, but with a positive fet l-neonatal prognosis, and the second with a pathologic placental component, presenting a late flattening growth curve with evolution towards fetal distress and a negative fetal-neonatal prognosis.

Close association between clathrin and the hydrophobic domain of boundary membranes in brain endocytic vesicles.

Purified bovine brain clathrin binds readily, in a pH-dependent fashion, to protein-free phospholipid bilayers. The association is tight and leads to inter-bilayer fusion, however, photolabeling studies using the amphiphilic photoreactive glycolipid 12-(4-azido-2-nitrophenoxy)stearoyl[1-14C]glucosamine provide no evidence for direct insertion of clathrin into the central, hydrophobic domain of of these target membranes. In contrast, similar photolabeling studies of isolated, intact clathrin-coated vesicles show that, in these structures, clathrin is readily accessible to a probe which is known to reside preferentially within the hydrophobic domain of the membrane. The results are consistent with a natural requirement, by clathrin, for accessory proteins in order to effect membrane penetration.