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S Ronchi

Publications and source records attributed to S Ronchi.

84 records · Page 5Linked to original sources
PubMedDate not supplied

Two-dimensional polyacrylamide gel electrophoresis map of bovine ovarian fluid proteins.

Molecular mechanisms underlying the cystic degeneration of ovarian follicles in the dairy cow have not been clarified yet. A useful approach for complementing endocrinological and clinical studies could be represented by the systematic analysis of the protein patterns in follicular and cystic fluid. With this aim, a two-dimensional polyacrylamide gel electrophoresis map of proteins contained in fluid from bovine ovarian follicles at different stages of development and from bovine ovarian cyst has been obtained. About 200 spots were detected after silver staining. Polypeptides from nine spots or series of spots have been identified by N-terminal sequencing, and further analysis of the map has been performed by gel comparison. Alpha-1-antitrypsin, albumin, serotransferrin and apolipoprotein A-I and A-IV were located on the map. Comparison between protein patterns revealed the differential expression of some spots among follicles of smaller diameter, follicles of larger diameter, and cysts. This could represent the first step toward the identification of proteins differentially expressed and associated with ovarian cyst development.

Amino Acid Sequence↗
PubMedDate not supplied

The primary structure of a basic (pI 9.0) fatty acid-binding protein from liver of Gallus domesticus.

The complete amino acid sequence of a basic (pI 9.0) fatty acid-binding protein purified from liver of Gallus domesticus was determined by automated Edman degradation of tryptic, CNBr/HFBA and Staphylococcus aureus protease peptides. The protein contains 125 amino acid residues which correspond to a molecular mass of 14094. The identification of the blocked N-terminus Ac-Ala required digestion of a SV-8 peptide with the acylamino acid-releasing enzyme prior to sequence analysis. Sequence comparison shows that chicken liver basic-FABP has a significant similarity to other proteins belonging to the superfamily of intracellular lipid molecule binding proteins. Moreover, these sequence data confirm that basic-FABP probably binds its substrate in a slightly different way when compared with other FABPs. Basic-FABP was submitted to the EMBL Data Library with an accession number of P80226.

Alkalies↗
PubMedDate not supplied

Isolation and some molecular properties of a trypsin-like enzyme from larvae of European corn borer Ostrinia nubilalis Hübner (Lepidoptera: Pyralidae).

A one-step high-yielding procedure is presented for the purification of a trypsin-like proteinase from Ostrinia nubilalis larvae, consisting of benzamidine-sepharose affinity chromatography. The purified enzyme was homogeneous as judged by SDS-PAGE. The enzyme presents a molecular mass of 24 650 Da, a maximum pH activity profile of 9.5, a remarkable thermal stability and an optimum temperature of about 53 degrees C Km values determined using N alpha-benzoyl-DL-arginine-ethylester and N alpha-benzoyl-DL-arginine-p-nitro-anilide were 3.2 x 10(-5) M and 4.1 x 10(-4) M respectively. The proteinase was inhibited by some typical serine proteinase inhibitors such as N alpha-tosyl-L-lysine chloromethyl ketone, soybean trypsin inhibitors, benzamidine and phenylmethylsulfonyl fluoride. In particular, it was competitively inhibited by benzamidine with a Ki of 1.2 x 10(-5) M, whereas it was not affected by cysteine proteinases inhibitors. Comparative analysis of the amino acid composition and N-terminal sequence of O. nubilalis proteinase confirmed that this enzyme is very similar to other serine proteinases from lepidopteran larvae.

Amino Acid Sequence↗
PubMedDate not supplied

Comparative aspects of the inactivation of fructose 1,6 bisphosphate aldolase by D- and l-glyceraldehyde 3-phosphate.

Fructose 1,6-bisphosphate aldolase inactivation by L- and D-glyceraldehyde 3-phosphate (Ga 3-P) obeys pseudo first-order kinetics. L-Ga 3-P is much more effective than the D-isomer: the Ki values obtained are 0.032 mM and 0.54 mM respectively. Kinetic analysis suggests that one residue of the active center region is involved in the inactivation mechanism: specifically, a cysteine residue appears to be responsible for the initial inactivation by L-Ga 3-P. Lysine and arginine residues become involved at further steps of the inactivation mechanism. No correlation between loss of thiol groups and decay of catalytic activity was observed for the enzyme treated with D-Ga 3-P. The role of lysine and arginine residues in this reaction is discussed.

Arginine↗
PubMedDate not supplied

[Lead concentrations in breast milk of women living in urban areas compared with women living in rural areas].

In the last twenty years a great interest has grown up about the accumulation of lead in the environment, because many studies have found relationship between exposure to low lead doses and neuropsychological impairment of children. The Authors have measured and then compared the lead content of milk from women living in city-areas and women living in rural areas, not having professional lead exposure. 34 samples of women milk from the rural areas and 20 samples from the city areas were examined: the lead mean concentration of the rural areas milk samples was 45.62 microgr/l with a range from 0 to 425 microgr/l; the mean concentration of the city areas samples was 126.55 microgr/l with a range from 1 to 472 microgr/l. The data were compared with the Student t-test and the difference was statistically significant at p = 0.01. The Authors examine the correlations between environmental lead accumulation and increased lead concentration in woman milk, laying stress on the possible hazard to health and neuropsychological development of children, mostly of those living in urban areas with heavy road traffic and industrial activity.

Female↗
PubMedDate not supplied

[Necrotizing lymphadenitis caused by Nocardia asteroides in a healthy girl].

A case of a healthy girl with a trauma in her right leg is described. Twelve hours later she developed fever and pain in the inguinal region. Two days later, she was admitted to the Hospital, and there, an aspiration of pus from the lymph node was performed, and this sample was sent for culture. The Gram smear showed gram-positive filamentous bacilli and when Kinyoun was used they were observed as weakly acid fast rods. After four days of incubation under aerobic conditions, white and hemolitic colonies were seen on human blood agar plates. Biochemical tests as urea hydrolysis and gelatin liquefaction were performed. To complete the identification it was sent to a reference laboratory, INEI-ANLIS Dr. Carlos G. Malbrán, where the isolate was confirmed as Nocardia asteroides sensu stricto. The patient was treated with intravenous cephalotin with good evolution. Therapy was followed with oral trimethoprim-sulfamethoxazole. This case is the first report of a Nocardia infection in the Hospital de Niños de Santa Fe. The fact that N. asteroides was isolated from an immunologically competent girl should be highlighted. This species is uncommon in children and it is rare in our region. In addition, N. asteroides infections are usually seen in pulmonary disease and rarely producing cutaneous infections.

Child, Preschool↗
PubMedDate not supplied

[Isolated pathogen microorganisms in respiratory samples from children with cystic fibrosis].

Cystic Fibrosis (CF) is characterized by a dysfunction of the exocrine secretion glands. The first symptoms often appear in the respiratory system which constitutes one of the most important morbimortality causes in these patients. Chronic respiratory tract colonization is caused mainly by bacteria such as Staphylococcus aureus, Haemophilus spp. and Pseudomonas aeruginosa. Respiratory samples from patients with CF (age group: 4 months to 11 years) were analyzed from November 2001 to August 2004. The most frequently isolated microorganisms were S. aureus (38.7%), P. aeruginosa (37.4%) and Haemophilus spp (15.3%). A high resistance to erithromycine (35.0%) and clindamicine (29.4%) was observed in S. aureus strains and 25.9% of them were methicillin-resistant. P. aeruginosa strains were mainly gentamicin-resistant (31.0%). The rate of ampicillin-resistant Haemophilus spp. was 23.0% and it was due to the presence of beta-lactamases, but a high trimethoprim-sulfamethoxazole resistance was observed in this microorganism (59.0%).

Bacteria↗
PubMedDate not supplied

Studies on the interaction of fructose 1,6-P2 aldolase with methylglyoxal.

Reaction of rabbit muscle fructose 1,6-P2 aldolase with methylglyoxal results in a biphasic loss of activity. The kinetics of the initial rapid phase are first order with respect to the inhibitor. Dihydroxyacetone phosphate and fructose 1,6 bisphosphate afford complete protection whereas inorganic phosphate provides only a partial protection against inactivation. The treatment with methylglyoxal modifies the aldolase ability to bind D-Ga3P and DHAP. Loss of activity correlates with the modification of 1.7 arginine residues but data suggest that probably one of these arginine residues is essential. A likely role of this residue could be its interaction with the C1 negatively charged phosphate binding site of the enzyme.

Aldehydes↗
PubMedDate not supplied

[The lead concentration in the converted and special-formula milks used in infant feeding].

In the last years a strict correlation between chronic exposure to low lead doses and neuropsychological impairment in first childhood is often reported in literature. The authors have measured and than compared the lead content of milk-based formulas, of special-formulas (hypoallergenic-protein formulas, lactose-free formulas, proteic-hydrolysate formulas) and soya formulas. 20 samples of milk-based formula, have been measured along with, 22 samples of special formula and 14 samples of soya formula. Lead mean concentration in milk-based formula was 73 +/- 139.11 microgr./l, whereas 23.95 +/- 13.76 microgr./l and 22.57 +/- 13.42 were measured in special formula and soya formula respectively. These results were compared with Student t-test and no significative difference was found. Lead mean concentration of milk-based formula was higher than that of special formula or soya formula. The authors hope milk-formula industry to have a more specific control on lead milk content for children feeding. In order to avoid possible toxic injuries in little infants, industry should certainly pay more attention both in supplying and in technological management of milk.

Animals↗