The instrumental and clinical laboratory follow-up of congenital hypothyroidism

Early diagnosis, L-tiroxine therapy and adequate follow-up are determinant to remove the damages resulting from hormone deficiency in congenital hypothyroidism (CH). In order to achieve a better intellectual development, the authors suggest some guidelines for a correct follow-up on the basis of their personal experience on a population of 160 children with CH. These guidelines include monitored therapy, biochemical controls, instrumental investigations, clinical and auxological serial examinations. To better predict the mental outcome of these patients as adults, the authors propose a longer follow-up till adolescents, especially in the children with more severe hypothyroidism at diagnosis.     

The production of monoenergetic fast neutrons of known flux: An improved method to identify the associated particle

The performance of a deuterium gas target to produce neutrons from the D(d, n)³He reaction is reported. The associated particle method is used. The associated particle is unequivocally identified with a telescope employing microchannel-plate electron multipliers and a silicon surface barrier detector, providing both time-of-flight (TOF) and energy (E) information. The system was set up at the 7 MV Van de Graaff CN accelerator of the laboratori Nazionali di Legnaro (Padova), and has been tested with deuteron energies from 2.5 to 6.5 MeV. About 300 tagged neutrons per s sr nA atm are produced. The TOF-E identification method to discriminate the associated particle will be used in the future in measurements at higher deuteron energies and with the reaction T(d, n)⁴He.     

A comparison of three multidisciplinarity indices based on the diversity of Scopus subject areas of authors’ documents,their bibliography and their citing papers

Scientometrics - In this paper, we compare the distribution of Elsevier Scopus subject areas of authors’ documents, their bibliographical references and their citing documents. We compute the...     

PIXE micro-beam mapping of metals in human peri-implant tissues

Previous investigations did not agree about the possible presence of titanium and other metals in the tissues around endosteal dental implants and joint prostheses. Indeed, while some authors reported diffusion of metals into the tissues, some others did not find evidence of this phenomenon. In the present study, four dental titanium implants, removed with the surrounding tissues from patients at various time intervals after the insertion, were studied by means of the micro-beam proton-induced X-ray emission (PIXE -beam) technique, which draws maps showing the tissue distribution of elements with a detection limit of about 1 ppm. One implant was built in commercially pure titanium, two others in titanium coated with titanium plasma spray, and the fourth in Ti–Al–V alloy. Their composition was confirmed by the PIXE -beam analyses. The removed samples were embedded in epoxy and processed with a cutting–grinding appliance, mounted on plastic holders, and ground up to a thickness of about 35 m. Optical microscope examinations were also carried out, to compare the optical findings with the elemental maps obtained with the PIXE -beam. One implant, removed after 70 days because the patient had developed peri-implantitis, had some inflammatory soft tissue attached, with no evidence of metal leakage. The other three implants had been removed after 6, 7 and 9 years of valid clinical service, because of the fracture of the prosthetic abutment or the implant stem. At the optical microscope, all these fixtures were embedded in mature bone. The elemental maps indicated small titanium deposits in about 5% of the bone bordering the implants, while aluminum, when present in the fixture, leaked diffusely into the surrounding bone and vanadium was not found in the tissues. These results suggest that titanium may be found occasionally in peri-implantar tissues, but has very little tendency to spread, while the presence of aluminum in the implant alloy may cause an important leakage of this metal.     

Transfer of melamine from feed to milk and from milk to cheese and whey in lactating dairy cows fed single oral doses

A study was conducted to evaluate the excretion pattern, after a single oral dose, of melamine from feed into milk, and the subsequent transfer to cheese and whey. The transfer of cyanuric acid was also investigated. Twenty-four lactating Holstein cows were randomly allocated to 4 treatments and received single doses of melamine as follows: 0.05, 0.50, 5.00, and 50.00 g/cow for groups D1, D2, D3, and D4, respectively. Individual milk samples were collected for melamine and cyanuric acid analyses on d 1, 2, 3, 4, 5, and 7. Milk collected individually from the second milking after melamine ingestion was used to make cheese on a laboratory scale. Melamine and cyanuric acid were extracted using a solid-phase extraction cartridge, and analyses were carried out by liquid chromatography-mass spectrometry/mass spectrometry. Maximal melamine concentrations occurred between 6 and 18 h after treatment and increased with log dose (linear and quadratic), ranging from 0.019 to 35.105 mg/kg. More than 60% of the melamine that was transferred to the milk was observed within 30 h after melamine ingestion. Melamine was not detected (limit of detection was 0.002 mg/kg) in milk 5 d after treatment in group D1, and 7 d after treatment in groups D2, D3, and D4. Blood urea nitrogen was not influenced by melamine ingestion. During cheese making, melamine was transferred mainly to the whey fraction. Cyanuric acid was not detected in any of the samples (milk, cheese, or whey). The excretion pattern of melamine in milk and whey may represent a health concern when cows ingest more than 0.50 g of melamine/d. However, only at intake levels of 5 and 50 g/d did cheese exceed the limits as set forth by the European Union. The results confirmed that melamine contamination of milk and milk products may be related not only to direct contamination, but also to adulteration of animal feeds.     

Analytical composition and rumen degradability of isogenic and transgenic corn varieties

Two different corn cultivars were compared with their genetically modified counterparts containing the gene coding for the Cry1A(b) protein of Bacillus thuringiensis (Bt). There were no analytical differences between the conventional and transgenic genotype kernels, whereas stovers from Bt⁺ plants had higher sugar (148.3 g kg^?1 versus 115.9 g kg^?1; P < 0.01) and lower NDF (592.7 g kg^?1 versus 631.5 g kg^?1; P < 0.05) contents than Bt^? maize. A comparison of the amino acid profiles showed higher phenylalanine content in kernels from the Bt⁺ plants (49.1 g kg^?1 vs 47.8 g kg^?1; P < 0.05) which was, however, not reflected in the protein content. The initial dry matter rumen degradability of the isogenic kernels was higher than that of Bt⁺ varieties (569.5 g kg^?1 vs 543.7 g kg^?1; P < 0.05), whereas the lower fibre content increased the dry matter (548.6 g kg^?1 vs 526.6 g kg^?1; P < 0.01) and protein (695.6 g kg^?1 vs 647.9 g kg^?1; P < 0.01) degradability after 24 h of incubation in stovers from Bt⁺ plants. The NDF degradability was higher in Bt^? corn varieties because of the higher proportion of hemicellulose in the total fibre. Copyright © 2003 Society of Chemical Industry