PubMed Health⌕ Search

Biomedical subjects

L Gastaldo

Publications and source records attributed to L Gastaldo.

15 recordsLinked to original sources
PubMed2001

The development of the suprarenal gland: surgical and anatomical considerations.

BACKGROUND: Aim of this research is to study the situation and relationships of the adrenal gland in the first stage of development in order to give some contributes for the application of laparoscopic adrenalectomy; in the meantime we describe the series of the debate changes occurring in the constitution of the cortex and medulla. METHODS: Analysis of histologic slices of thoraco-abdominal and abdominal regions of human embryos and fetuses ranging from the fifth (12 mm CR) to the twentieth week (170 mm CR). RESULTS: At 12 mm CR an unique type of cells is present in the cortex; at 16 mm CR there are two different groups of cells. Sympathogonia enter into the cortex at 16 mm CR. The right adrenal gland seems enclosed into the liver and a ligament containing the middle adrenal vein reaches the vena cava inferior sulcus. The left adrenal gland, through the coelomic cavity, is in relationship with the stomach, the medial border of the spleen and the pancreatic body contained in the primitive dorsal mesogastrium. CONCLUSIONS: The timing of penetration of the ganglion cells into the cortex is defined as well as the hypothesis that the matrix of the fetal and definitive cortex is the same: moreover the study of the early development allows to understand the main characteristics of both the adrenal glands which are significant for a rational and differential laparoscopic approach.

Adrenal Glands↗
PubMed1997

Targeted screening for elongation factor Tu binding antibiotics.

The development of a screen targeted to antibiotics which bind elongation factor Tu (EF-Tu) is described. The method was based on selection of antimicrobial activities which were antagonized by exogenous EF-Tu. Kirromycin, a known inhibitor of EF-Tu, was positive in this screen. Among 47,000 microorganisms screened, several producers of kirromycin-type antibiotics were detected and the novel antibiotics GE2270 and GE37468 were discovered. These thiopeptide molecules constitute, along with amithiamycin, a novel class of antibiotics acting on EF-Tu.

Actinomycetales↗
PubMed1997

Isolation and structure elucidation of 7,8-dideoxy-6-oxo-griseorhodin C produced by Actinoplanes ianthinogenes.

A novel product, isolated from a culture broth of Actinoplanes ianthinogenes fermented for producing purpuromycin, was purified and its structure established on the basis of physico-chemical data and chemical reactions. The new product resulted to be structurally related to griseorhodins, a group of hydroquinonic antibiotics obtained from Streptomyces californicus. This compound showed a weak activity against Gram-positive and resulted inactive against Gram-negative bacteria and Candida albicans.

Anti-Bacterial Agents↗
PubMed1996

Antibiotic GE37468A: a new inhibitor of bacterial protein synthesis. III. Strain and fermentation study.

GE37468A is a new thiazolyl peptide antibiotic acting on Elongation Factor Tu, produced by fermentation of Streptomyces sp. ATCC 55365. The low (< 10 mg/liter) and poorly reproducible antibiotic productivity of the original soil isolate hampered the development of a scalable fermentation process. A tenfold increase of GE37468A productivity was achieved by selection of spontaneous morphochromatic variants, which appeared at high frequency in the wild type population. The higher producing ATCC 55365/O/5 colony was tyrosinase defective and blocked in the aerial mycelium differentiation (Amy-Mel- phenotype). The fermentation process of this stable and purified strain was rapidly optimized to achieve a further fourfold improvement in a fed-batch process.

Anti-Bacterial Agents↗
PubMed1994

Purification procedure for bacterial translational initiation factors IF2 and IF3.

In bacteria the initiation of protein synthesis is a complex phenomenon in which specific proteins, termed initiation factors (IFs) IF1, IF2, and IF3, are involved. Notwithstanding the progress made in understanding their functions, the precise molecular mechanisms of action of these factors remain somewhat obscure. One reason for this lack of knowledge is the difficulty involved in purifying sufficient quantities of these proteins. We have developed a new procedure for purification of IFs from recombinant Escherichia coli strains producing high levels of E. coli IF3 and Bacillus stearothermophilus IF2. This new procedure is quicker than previous methods, easily scaled up to large volumes, and can be used, with only minor modifications, for different IFs. This new purification method consists essentially of one chromatographic (FPLC) separation on an ion-exchange resin (S-Sepharose fast-flow or Mono-S HR). Using this procedure we have been able to obtain chromatographically pure and biologically active preparations of both IF2 and IF3.

Bacterial Proteins↗
PubMed1992

Isolation, structure determination and biological activity of A-16686 factors A' 1, A' 2 and A' 3 glycolipodepsipeptide antibiotics.

When Actinoplanes strain ATCC 33076, the producer of A-16686 A1, A2 and A3 complex, is fermented in a suitable medium three additional factors, designated A' 1, A' 2 and A' 3 are produced. These were isolated and characterized, and were shown to differ from the parent components of the original complex by lacking one mannose unit. Bioconversion of A factors into A' factors was achieved by incubation with the mycelium of Actinoplanes ATCC 33076. Factor A' 2 has better antibacterial activity than A2 against some bacteria.

Actinomycetales↗
PubMed1992

[Postoperative infections. A prospective analysis of 1396 cases].

Postoperative infections are the most frequent complications in surgery and are the commonest cause of the lengthening of hospital stay. The purpose of this study is to prospectively evaluate the incidence and predisposing factors of postoperative infections in 1396 surgical patients admitted to our Institute from 1984 to 1988. Patients undergoing minor surgical procedures (wound less than 2 cm) were excluded from the study. Patients were evaluated daily during hospital stay for onset of infections and results recorded on data sheet. Hemocultures in septic patients and samples of exudate at site of infection were taken whenever possible for aerobic and anaerobic cultures. 368 patients (26.36%) had at least one postoperative septic complication; (79 of them [5.65%] had two or more infections). The following infections were recorded: wound infections: 148 (10.60%); respiratory tract infections: 144 (10.31%); urinary tract infections 125 (8.95%); miscellaneous infections 11 (0.78%); thrombophlebitis 23 (1.64%); FUO 10 (0.71%). The most important predisposing factor for wound infection was endogenous contamination (wound infections: 18/499 [3.60%] in clean, 42/594 [7.67%] in potentially contaminated, 57/217 [26.26%] in contaminated and 31/86 [36.04%] in dirty operations). The duration of the anaesthesia was found to correlate with an increased incidence of respiratory tract infections (4.49% anaesthesia less than 60 min; 7.21% anaesthesia greater than 60 less than 120 min; 15.31% greater than 120 min anaesthesia). Urinary infections were more frequent when the patients where catheterized at least once in the postoperative period (24.86% vs 3.2%).

Fever of Unknown Origin↗
PubMed1991

Radioimmunolocalization of pelvic recurrences from rectosigmoid cancer employing 111In anti-CEA F(ab')2.

Thirty-two immunoscintigraphic studies have been performed in 26 patients previously operated upon for rectosigmoid cancer, for an early detection of pelvic recurrence, employing 111In anti-CEA, F(ab')2. The sensitivity was 1, specificity 0.76 and accuracy 0.84, leading to a positive predictive value of 0.69 and a negative value of 1. The combined use of a non-imaging surgical probe in 6 of the 10 patients who underwent second look surgery, detecting the 111In radioactivity used for RIS, improved diagnostic accuracy, ruling out the presence of tumors in 3 patients with false positive RIS.

Antibodies, Monoclonal↗
PubMed1991

Antibiotic GE2270 a: a novel inhibitor of bacterial protein synthesis. I. Isolation and characterization.

A novel antibiotic, GE2270 A, was isolated from the fermentation broth of a strain of Planobispora rosea. The product was found to inhibit bacterial protein synthesis. Structural characteristics showed similarities between GE2270 A and thiazolyl peptides such as micrococcin which is known to inhibit protein synthesis by acting directly on the ribosome. Despite this similarity GE2270 A showed functional analogy to kirromycin-like antibiotics and pulvomycin, as its molecular target was found to be elongation factor Tu (EF-Tu). GE2270 A is active against Gram-positive microorganism and anaerobes and differs from the other EF-Tu inhibitors in its spectrum of antimicrobial activity.

Actinomycetales↗
PubMed1989

A42867, a novel glycopeptide antibiotic.

A42867 is a new glycopeptide antibiotic of the ristocetin-vancomycin class active against aerobic and anaerobic Gram-positive bacteria. A42867 is produced by a strain of Nocardia nov. sp. ATCC 53492. A42867 was isolated during a screening program aimed at the discovery of new members of this glycopeptide class of antibiotics, by affinity chromatography based on an acyl-D-alanyl-D-alanine probe. The structure of A42867 was elucidated by fast atom bombardment MS, high field 2D 1H NMR spectroscopy, and HPLC analysis of the hydrolyzed carbohydrates. A42867 differs from vancomycin in the sugar portion and in the presence of only one chlorine atom in the peptide core. Its biological activity on Gram-positive aerobic and anaerobic bacteria is similar to that of other antibiotics of this group.

Aminoglycosides↗
PubMed1987

A40926, a new glycopeptide antibiotic with anti-Neisseria activity.

In the course of a search for glycopeptide antibiotics having novel biological properties, we isolated A40926. Produced by an actinomycete of the genus Actinomadura, A40926 is a complex of four main factors which contain a fatty acid as part of a glycolipid attached to the peptide backbone. Its activity was, in most respects, similar to that of other glycopeptides, such as vancomycin and teicoplanin. However, in addition to inhibiting gram-positive bacteria, A40926 was very active against Neisseria gonorrhoeae. A40926 was rapidly bactericidal for N. gonorrhoeae clinical isolates at concentrations equal to or slightly higher than the MIC. In mice, levels in serum were higher and more prolonged than those of an equivalent subcutaneous dose of teicoplanin. These properties suggest that A40926 may have potential in the therapy of gonorrhea.

Anti-Bacterial Agents↗
PubMed1984

Teicoplanin, a new antibiotic from Actinoplanes teichomyceticus nov. sp.

Teicoplanin, a new glycopeptide antibiotic belonging to the same family as vancomycin, inhibits cell wall synthesis in Bacillus subtilis; the inhibition is accompanied by an intracellular accumulation of UDP-N-acetyl-muramyl-pentapeptide. A cell-free system from Bacillus stearothermophilus, capable of synthesizing peptidoglycan, is 50% inhibited by teicoplanin at 40 micrograms/ml and 100% inhibited at 100 micrograms/ml; suppression of peptidoglycan synthesis is accompanied by parallel accumulation of the lipid intermediate. Teicoplanin binds to cell walls and forms a complex with N,N'-diacetyl-L-lysyl-D-alanyl-D-alanine. The association constant of this complex is 2.56 X 10(6) liters mol-1, calculated by spectrophotometric titration. The mechanism of action of teicoplanin is discussed in comparison with those of other inhibitors of cell wall biosynthesis, namely, vancomycin, ristocetin, and gardimycin.

Acetylglucosamine↗
PubMed1984

Inhibitory activity and resistance to hydrolysis by beta-lactamases of some (D,L)-7-(alpha-fluoroacylamino)cephalosporins.

The synthesis of a series of (D,L)-7-(alpha-fluoroacylamino)-cephalosporanic acids are described. In vitro antimicrobial activity was determined in comparison with the corresponding non-fluorinated compounds. None of them were found to be better than clinically used cephalosporins. Resistance to and inhibition of beta-lactamases from gram-negative organisms were also determined. All the fluorinated derivatives were found to be as resistant to hydrolysis by Escherichia coli R+TEM beta-lactamase as the corresponding non-fluorinated compounds, but resulted more resistant (from 2.3 to 61.2 times) to Enterobacter cloacae 214 beta-lactamase. Title compounds were also found to be better inhibitors of E. cloacae 53 and E. cloacae 214 beta-lactamases than the related non-fluorinated cephalosporins.

Bacteria↗