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Biomedical subjects

F Negretti

Publications and source records attributed to F Negretti.

At least 19 recordsLinked to original sources
PubMed2003

Pro- and pre-biotics administration in preterm infants: colonization and influence on faecal flora.

Prolonged administration of probiotic in preterm babies induce a rise of specific IgA and IgM antibodies against probiotic. This fact explains why presence of living germs in stools almost disappeared in spite of continuous administration. However some positive influences were observed: decreased ratio of aerobic/anaerobic. Increased ratio of gram +/gram - germs. Prebiotic administration induces after 28 days a significant increase of faecal bifidobacteria and frequency and consistency of stools were more similar to those observed in subjects fed with human milk.

Bifidobacterium↗
PubMed2002

Supplementation of a bovine milk formula with an oligosaccharide mixture increases counts of faecal bifidobacteria in preterm infants.

BACKGROUND: The establishment of a balanced intestinal microflora which may protect against infection is desirable for the preterm infant. OBJECTIVE: To investigate the effect of a preterm formula milk supplement consisting of oligosaccharides in similar proportions to human milk on the faecal flora and stool characteristics of preterm infants. STUDY DESIGN: To resemble the effect of human milk, an oligosaccharide mixture consisting of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides was used to supplement a standard preterm formula at a concentration of 10 g/l. This supplemented formula was studied in 15 preterm infants, and the results were compared with those found in 15 infants fed a formula supplemented with maltodextrin as placebo. A group fed fortified mother's milk was investigated as a reference group (n = 12). On four days during a 28 day feeding period (1, 7, 14, and 28), the faecal flora was investigated, and stool characteristics, growth, and possible side effects were recorded. RESULTS: During the study period, the number of bifidobacteria in the group fed the oligosaccharide supplemented formula increased to the upper range of bifidobacteria counts in the reference group. The difference between the supplemented and non-supplemented groups was highly significant (p = 0.0008). The stool characteristics were also influenced by the supplement: the stool frequency after 28 days was significantly lower in the control group than in the oligosaccharide supplemented group (p = 0.0079) and the reference group (p < 0.0001). Over the study period, the stool consistency in the control group became harder, but remained fairly stable in the other two groups. There was no effect of the different diets on the incidence of side effects (crying, regurgitation, vomiting) or on weight gain or length gain. CONCLUSION: Supplementing preterm formula with a mixture of galacto- and fructo-oligosaccharides at a concentration of 10 g/l stimulates the growth of bifidobacteria in the intestine and results in stool characteristics similar to those found in preterm infants fed human milk. Therefore prebiotic mixtures such as the one studied may help to improve intestinal tolerance to enteral feeding in preterm infants.

Animals↗
PubMed2001

Tumor grade heterogeneity in urothelial bladder carcinoma--proposal of a system using combined numbers.

OBJECTIVE: There is no consensus for grading when more than one grade is present in bladder carcinoma. We propose a grading system that considers the primary (most common) and secondary (second most common) grade of bladder cancer. Grade was correlated with stage of the tumors. MATERIAL AND METHODS: We studied 293 bladder transurethral resections or radical cystectomies. Grade was considered as 1, 2 or 3 according to the 1999 World Health Organization system. The number was repeated when only one grade was seen. A final score was obtained which ranged from 2 to 6. All cases were also graded according to the highest grade area even if it was focal. RESULTS: According to the highest grade area, the distribution was 80 (74.07%), 27 (25.00%) and 1 (0.92%) for grade 1; 31 (24.03%), 69 (53.48%) and 29 (22.48%) for grade 2; and 0 (0%), 17 (30.35%) and 39 (69.64%) for grade 3, corresponding to the stages Ta, T1 and T2-T3, respectively. Using the system of combined numbers, grade 2 was stratified into subgroups 1 + 2 and 2 + 2 which are statistically different (p < 0.05) when considering stage. In grade 3, there was also a trend for statistical difference (p = 0.066) between grades 2 + 3 and 3 + 3. CONCLUSIONS: The grading system of combined numbers, stratifies grade 2 into subgroups 1 + 2 and 2 + 2, and grade 3 into subgroups 2 + 3 and 3 + 3 which are statistically different when considering stage. This grading system of combined numbers takes into consideration tumor heterogeneity and may be of value in prospective studies for analysis of prognosis and therapeutic response.

Carcinoma, Transitional Cell↗
PubMed1998

Salivary immune responses after gingival immunization with tetravaccinal and bivaccinal formulations of inactivated micro-organisms.

Two groups of rats were treated separately, fourteen times during three months, by rubbing at gingival mucosa with two antigenic mixtures: (i) Staph. aureus, Str. faecalis, E. coli and Prot. vulgaris; (ii) Str. mutans and Act. viscosus. At the end of the treatments the increases of specific salivary IgAGM ranged from 202.6% (Str. faecalis) to 312.7% (E. coli) in the case of tetravaccinal association and from 123% (Act. viscosus) to 171.4% (Str. mutans) in the one of bivaccinal formulation.

Animals↗
PubMed1997

[Microbiological control of drugs with antimicrobial properties with membrane filtration: problems, proposals, prospects].

The attention to the difficulty to performing the control of sterility (and also of contamination) of pharmaceuticals with antimicrobial activity (antibiotics, chemotherapeutic agents, etc.) or containing preservatives is called. On the basis of our and others investigations, the technique of the membrane filtration (employed usually) is unable to eliminate the interferences on the microbial growth. The membranes used for the filtration of antimicrobial agents acquire antimicrobial properties, resulting in: a) appearance of inhibition zones onto agar plates previously inoculated with microbial strains; b) decrease of the number of CFU after artificial contamination of the membranes (more sensitive method); c) absence or partial growth into culture broths of microbial strains contaminant the membranes; d) antimicrobial activity of the culture broths inoculated with used membranes. The separate washing with 300 ml and upper volumes of peptone water does not eliminate completely the antimicrobial activity of the membranes. If the filtration is associated to treatments with suitable neutralisant substances, it is possible to eliminate partially the antimicrobial activity of the membranes. In No. 10 antibiotics, a total neutralization of the antimicrobial activity was obtained in No. 4 cases (40%). In No. 14 chemotherapeutic agents, We have obtained a total neutralization of the antimicrobial activity in No. 11 cases (78.57%) and a partial remission in No. 3 cases (21.43%). In No. 18 disinfectant, We have obtained a complete disappearance of the drawback in No. 16 (88.8%) cases and a partial disappearance in No. 2 (11.2%) cases. Only in the case of the preservatives (No. 3 single and 16 associations), we have obtained a total remission of the interferences in all cases. For the neutralization, some classic neutralizers (albumin, p-aminobenzoic acid, beta-lactamase, cysteine, Ca+2, egg yolk, Fe+3, heparin, hydroxylamine, thymidine, Tween 20) and a new neutralizing agent (ascorbic acid) were employed. Thus, it is necessary to find suitable neutralizing agents or to research new types of filtering membranes. In the meantime, the production of chemo-antibiotic agents should be carried out according to stingent criteria of asepsis.

Anti-Infective Agents↗
PubMed1997

[The "rapidity" factor in the specific immunity response after oral vaccination].

The vaccination per os induces early, specific immunoglobulinic responses in intestine, saliva, bile and urine, as well as in the respiratory apparatus, involving above all sIgA, but also IgG and IgM. The notion of the rapidity of the specific immunitary responses constitutes an important acquisition at immunological level (mechanisms of the antibody-poiesis) and, also, from the therapeutic and analytical point of view. The use of oral vaccines is fully justified by the rapidity of the immune reactions not only at enteric level, but also in the different districts of the animal organisms (gingives, saliva, biliary, urinary and respiratory tract). The availability of immunizing agents is a remarkable occurrence from the clinical point of view, in that the non rare failure of the chemo-antibiotic-therapy are a common knowledge. Its far prophylaxis, also, the rapidity of action of the oral vaccines is very important; in the case of parenteral vaccination, instead, a latency time of about a week is necessary. The rapidity of the immune responses after oral immunization give an evaluation of the immunizing activity of antigenic formulations in a short time, with evident advantages in the point both of a scientific and economic view. Moreover, it is possible to perform the quali-quantitative analysis of vaccinal preparations in a few of days.

Administration, Oral↗
PubMed1997

[Experimental-practical study of some methods for culturing and counting enterobacteria from raw materials and oral medical preparations].

The technique of enterobacteria enumeration according to F.U., by rivivification in Lactose Broth for 5 h at 37 degrees C and subsequent incubation in Enterobacteriaceae Enrichment Broth, causes artful increases of the number of enterobacteria, often resulting higher than the total microbial charge. To eliminate the drawback we have assayed other two methods: a) incubation in Soybean Casein Digest Broth for 5 h at 37 degrees C, followed by enumeration onto Violet Red Bile Dextrose Agar plates; b) incubation into Soybean Casein Digest Agar plates for 5 h at 37 degrees C, followed by enumeration onto overlayed Violet Red Bile Dextrose Agar. The experimental investigations were performed on 8 artificially stressed (heating, freezing) strain of Enterobacteriaceae and carried out the superiority of the method onto Soybean Casein Digest Agar + Violet Red Bile Dextrose Agar plates. This method was tested on No. 302 samples of raw materials and pharmaceutical preparations, that shown an enterobacterial charge higher than 100 C.F.U. in 24 cases (8%). On the contrary, the enumeration of the enterobacteria according to the F.U. method (Lactose Broth + Enterobacteriaceae Enrichment Broth + Violet Red Bile Dextrose Agar) carried out an enterobacterial charge higher than 100 C.F.U. in 270 cases (89.4%). Indeed, the artful increase of the number of enterobacteria may make unacceptable pharmaceutical preparations suitable for the market. The employment of the method of enumeration of the enterobacteria onto Soybean Casein Digest Agar + Violet Red Bile Dextrose Agar plates is augured.

Colony Count, Microbial↗
PubMed1992

Study on the influence of adsorbent substances against the antigen activity of inactivated orovaccines.

Specific IgAGM, IgA and IgG levels were evaluated in two groups of rabbits orally treated with inactivated vaccine consisting of Escherichia coli, Proteus vulgaris, Staphylococcus aureus and Streptococcus faecalis and with the same vaccine supplemented with charcoal and kaolin, respectively. The determinations demonstrated that charcoal and kaolin do not have a significant, negative effect on immunoresponses at the intestinal and hematic level after both medium (two-week) and prolonged (four-week) treatment.

Administration, Oral↗
PubMed1992

The microbial controls of antiseptics and disinfectants by membrane filtration: experimental evaluation of the interferences.

Microbiological investigations made by membrane filtration method on antiseptics and disinfectants demonstrated that the filtering membranes present very frequently a remarkable antimicrobial activity, even after washing with 300 ml of peptone water according to the guidelines of the Pharmacopoeia. The observed phenomena (appearance of inhibition zones, disappearance or decrease of the number of colonies forming units, release of antimicrobial properties to the cultural broths) can seriously diminish the validity of microbiological controls of antiseptics and disinfectants.

Anti-Infective Agents, Local↗
PubMed1991

Research on the chemical inactivation of antibiotic activity in assays of sterility and contamination of pharmaceuticals.

Membrane filtration, frequently used for removing antibacterial activity in assays of sterility and contamination of the antibiotics, presents the drawback of adsorption of antibiotic to membrane. The washing with large volumes of peptone water removes partially interferences with microbial growth. We evaluated the inactivating action of some chemical substances (albumin, calcium pantothenate, heparin, hydroxylamine, tri-valent iron) on the antimicrobial activity of membranes employed for antibiotic filtration. The results are not positive for the use of chemical substances in the antibiotic activity neutralization. In fact the per cent reduction of inhibition zones ranges from -61.5% to +20.0% and the inhibiting activity on the growth of colony forming units (CFU) oscillates from 89.6% to 100%. Discovery of new neutralizing substances and severe measures of asepsis in pharmaceutical production are recommended.

Anti-Bacterial Agents↗
PubMed1990

Remarkable increases of salivary IgE levels in allergic syndromes.

Serum and salivary IgE levels were tested by indirect ELISA in patients with allergic contact dermatitis and allergic asthma or rhinitis. The remarkable increases of salivary IgE (from 928.4% mean augmentation in allergic asthma or rhinitis to 2686.2% in allergic contact dermatitis) suggest the idea of using saliva in IgE titration.

Humans↗
PubMed1990

[Experimental study of the course of the immune response at the urinary level following repeated oral vaccination].

The Progression of the specific immunoreactions in the urines of rabbits vaccinated by oral route from 1 to 10 times with 20-40 billion of some antigens (E. coli, Proteus vulgaris, Staph aureus, Str. faecalis), administered daily or by-weekly, has been evaluated by agglutination and ELISA. The immunoenzymatic ELISA technique has revealed increases of specific immunoglobulins also one day after the first oral administration of the antigens and a final progression of IgA titres (after ten treatments) from 81% to 798%, according to the various antigens and the different posology. The highest values have been obtained using the posology of 40 billion and the bi-weekly sequence.

Administration, Oral↗