Search PubMed⌕ Search

Biomedical subjects

A Marini

Publications and source records attributed to A Marini.

At least 37 records · Page 2Linked to original sources
PubMed2003

Prebiotic concept for infant nutrition.

In the neonatal period, the intestine is colonised in a stepwise process that depends on mode of delivery, environmental factors, bacterial interactions, and the host itself resulting in a colonisation with a complex heterogeneous bacterial flora. Oligosaccharides have been identified as an important prebiotic factor of human milk As long as analogues of human milk oligosaccharides are not available now and in the near future it is aimed to resemble the prebiotic effect of human milk by oligosaccharides from available sources. In the present study in preterm infants, a mixture of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides has been tested. The mixture of GOS/FOS was composed to mimic the molecule size distribution of human milk oligosaccharides. Microbiological analysis of the faces was performed before and 7, 14, and 28 days after start of supplementation and stool characteristics have been recorded. Maltodextrin was used as placebo and infants fed human milk have been used as reference. After a 28 days feeding period, the number of bifidobacteria of the group fed the oligosaccharide supplemented formula was in the upper range of the reference group whereas the numbers of the group fed the formula supplemented with the placebo were in the lower range of the reference group (placebo: 7.9 +/- 0.83 and GOS/FOS mixture: 10,0 +/- 2.05 log 10 CFU/g wet stool; reference (M +/- SD): 7.14-10.7 log 10 CFU/g wet stool). Stool characteristics in the group fed the supplemented formula were close to those found in the human milk fed infants. In summary, supplementation of a preterm formula with a mixture of galacto- and fructo-oligosaccharides has a stimulating effect on the growth of bifidobacteria in the intestine and results in more frequent produced and softer stools. Thus, prebiotic mixtures such like the studied oligosaccharide mixture might help in improving intestinal tolerance to enteral feeding in preterm infants.

Bifidobacterium↗
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↗
PubMed2003

Oligosaccharides might stimulate calcium absorption in formula-fed preterm infants.

UNLABELLED: Among other components of human milk, oligosaccharides might contribute to the high efficiency of calcium absorption of breastfed infants. In adults, it can be shown that dietary oligosaccharides can improve calcium absorption. The present analysis was performed to evaluate a possible influence of dietary oligosaccharides on parameters of calcium metabolism in preterm infants. The concentrations of calcium and phosphorus in plasma and in spot urine samples as well as the plasma activity of the alkaline phosphatase were measured in preterm infants fed either a standard formula (n = 15) or a formula supplemented with dietary oligosaccharides (n = 15) at the end of a 4-wk feeding period. CONCLUSIONS: There was no influence of the different diets on the plasma concentration of calcium and phosphorus or on the plasma activity of alkaline phosphatase. In urine, there was a tendency towards higher calcium concentrations in the group fed the supplemented formula compared concentrations in the group fed the standard formula. The concentrations of phosphate were not significantly different and, as a consequence, there was a tendency towards a higher Ca/P molar ratio in the group fed the supplemented formula. The data indicate that the calcium absorption might be influenced by the dietary oligosaccharides. Thus, the possible effect of dietary oligosaccharides on calcium homeostasis should be included in the discussion concerning the consequences of the use of dietary oligosaccharides in preterm infant nutrition.

Absorption↗
PubMed2002

Prevalence of respiratory syncytial virus infection in Italian infants hospitalized for acute lower respiratory tract infections, and association between respiratory syncytial virus infection risk factors and disease severity.

This study was designed to collect data on the prevalence of respiratory syncytial virus (RSV) infection in Italy in infants hospitalized for lower respiratory tract infections, and to evaluate which of the recognized risk factors might be associated with disease severity. Thirty-two centers throughout Italy participated in the study. Over a 6-month period (November 1,1999 to April 30, 2000), we evaluated all children < 2 years of age hospitalized for lower respiratory tract infections. All subjects were tested for RSV within 24 hr of hospitalization by using an immuno-enzymatic diagnostic test (Abbott Testpack, RSV). Logistic regression was used to identify the factors that might be associated with more severe disease or could increase the likelihood of RSV positivity in hospitalized infants. Out of a total of 1,232 children enrolled, 40.6% were found to be RSV-positive (RSV+). The peak of the RSV epidemic occurred in February, while the lowest prevalence of RSV positivity was seen in November (P < 0.05). A high proportion of study subjects had low birth weight and low gestational age. The clinical diagnosis at hospitalization was bronchiolitis in 66.7%, pneumonia in 15.3%, and wheezy bronchitis in 18.1%. In the bronchiolitis group, a higher prevalence of RSV+ was found in patients with gestational age or= 36 weeks (P < 0.04). No differences were found in the proportion of RSV+ patients in the three gestational age subgroups with pneumonia and wheezy bronchitis (P > 0.05, each comparison). Independent of the clinical diagnosis at admission, RSV infection was associated with more severe respiratory impairment. Environmental smoke exposure was higher in subjects with bronchiolitis than in those with wheezy bronchitis (P < 0.04), and RSV+ was positively related with the birth order (P < 0.05). The presence of older siblings and birth order plays an important role in RSV infection. The collected data show that, in Italy, RSV is an important cause of lower respiratory tract infection in infants. Gestational age, birth order, birth weight, and exposure to tobacco smoke affected the prevalence and severity of RSV-related lower respiratory tract disease.

Acute Disease↗
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

Thermoanalytical and spectroscopic characterisation of solid-state retinoic acid.

Thermoanalytical (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TG/FTIR)) and spectroscopic (X-ray diffraction (XRD), ultraviolet-visible (UV-Vis), mass spectrometry (MS) and Fourier transform infrared diffuse reflectance (DRIFT) measurements have been used to characterise solid-state retinoic acid (RA) from a chemico-physical point of view. Between 130 and 160 degrees C, a phase transition takes place that does not correspond to the transition between the known monoclinic and triclinic phases (DSC and XRD evidence). By annealing in air (in the 130-160 degrees C temperature range and for different times), an exothermic oxidative degradation occurs that, depending on the thermal treatment, competes with the mentioned phase transition (TGA evidence). Spectroscopic techniques (UV-Vis, MS and DRIFT) allow one to conclude that the new solid phase is still constituted by retinoic acid with a different orientation of the side chain. Finally, RA does not undergo stable melting: the fragmentation patterns, both in air and in nitrogen, have been examined by TG/FTIR.

Antineoplastic Agents↗
PubMed2001

Functional characterization of an ammonium transporter gene from Lotus japonicus.

NH(4)(+) is the main product of symbiotic nitrogen fixation and the external concentration of combined nitrogen plays a key regulatory role in all the different step of plant-rhizobia interaction. We report the cloning and characterization of the first member of the ammonium transporter family, LjAMT1;1 from a leguminous plant, Lotus japonicus. Sequence analysis reveals a close relationship to plant transporters of the AMT1 family. The wild type and two mutated versions of LjAMT1;1 were expressed and functionally characterized in yeast. LjAMT1;1 is transcribed in roots, leaves and nodules of L. japonicus plants grown under low nitrogen conditions, consistent with a role in uptake of NH(4)(+) by the plant cells.

Amino Acid Sequence↗
PubMed2001

Physicochemical study of the solid forms of a new drug.

GV150526A is a new drug recently developed by GlaxoWellcome. It belongs to a novel group of 2-carboxyindole derivatives and is therapeutically effective in the treatment or prevention of CNS disorders resulting from neurotoxic damage. We present a physicochemical characterization of the three solid forms (hydrates) of GV150526A carried out mainly by thermal methods. It is shown that: (1) the different forms can be qualitatively and quantitatively distinguished by their thermal properties; (2) dehydration is followed or accompanied by a structural relaxation of the substrate that takes place at different rates and with different enthalpies in the three forms; (3) two of the solid forms can be converted into a phase that is thermodynamically stable at room temperature by partial dehydration/rehydration in a solid/vapor process.

Calorimetry, Differential Scanning↗
PubMed2001

Neurofibromatosis-1 and ampullary gangliocytic paraganglioma causing biliary and pancreatic obstruction.

Gangliocytic paragangliomas (GPs) are exceedingly rare tumors that arise in close proximity of the papilla of Vater. Nevertheless, jaundice is an uncommon presenting symptom, reported in only 3 of 125 cases described in the literature to date, with gastrointestinal bleeding being more common. Association between GPs and neurofibromatosis 1 (NF-1), described in two patients, may be more than casual, being the frequency in normal population 1:3,000. We report an additional case of this association, presenting for the first time with simultaneous obstruction of the common biliary duct, and of the main pancreatic duct. Previous cases of GPs with jaundice and/or NF-1 are reviewed, and updating of the histogenesis presented.

Ampulla of Vater↗
PubMed2000

First search for gravitational wave bursts with a network of detectors

We report the initial results from a search for bursts of gravitational radiation by a network of five cryogenic resonant detectors during 1997 and 1998. This is the first significant search with more than two detectors observing simultaneously. No gravitational wave burst was detected. The false alarm rate was lower than 1 per 10(4) yr when three or more detectors were operating simultaneously. The typical threshold was H approximately 4x10(-21) Hz-1 on the Fourier component at approximately 10(3) Hz of the gravitational wave strain amplitude. New upper limits for amplitude and rate of gravitational wave bursts have been set.

Journal Article↗
PubMed2000

Antihistamine terfenadine potentiates NMDA receptor-mediated calcium influx, oxygen radical formation, and neuronal death.

We previously reported that the histamine H1 receptor antagonist terfenadine enhances the excitotoxic response to N-methyl-D-aspartate (NMDA) receptor agonists in cerebellar neurons. Here we investigated whether this unexpected action of terfenadine relates to its antihistamine activity, and which specific events in the signal cascade coupled to NMDA receptors are affected by terfenadine. Low concentrations of NMDA (100 microM) or glutamate (15 microM) that were only slightly (<20%) toxic when added alone, caused extensive cell death in cultures pre-exposed to terfenadine (5 microM) for 5 h. Terfenadine potentiation of NMDA receptor response was mimicked by other H1 antagonists, including chlorpheniramine (25 microM), oxatomide (20 microM), and triprolidine (50 microM), was prevented by histamine (1 mM), and did not require RNA synthesis. Terfenadine increased NMDA-mediated intracellular calcium and cGMP synthesis by approximately 2.4 and 4 fold respectively. NMDA receptor-induced cell death in terfenadine-treated neurons was associated with a massive production of hydrogen peroxides, and was significantly inhibited by the application of either (+)-alpha-tocopherol (200 microM) or the endogenous antioxidant melatonin (200 microM) 15 min before or up to 30 min after receptor stimulation. This operational time window suggests that an enduring production of reactive oxygen species is critical for terfenadine-induced NMDA receptor-mediated neurodegeneration, and strengthens the importance of antioxidants for the treatment of excitotoxic injury. Our results also provide direct evidence for antihistamine drugs enhancing the transduction signaling activated by NMDA receptors in cerebellar neurons.

Animals↗
PubMed2000

A clinical trial of intravenous vinorelbine tartrate plus tamoxifen in the treatment of patients with advanced malignant melanoma.

BACKGROUND: The aim of the current trial was to assess the efficacy and toxicity of weekly intravenous vinorelbine tartrate with daily oral tamoxifen in the treatment of patients with advanced or metastatic malignant melanoma. METHODS: Thirty-one patients were treated with vinorelbine tartrate, 30 mg/m(2) intravenously, weekly every 13 weeks and then every 2 weeks thereafter until progression of disease or severity of toxicity warranted discontinuation. Tamoxifen, 10 mg orally, twice a day was administered daily starting on Day 1 of chemotherapy with vinorelbine tartrate. Thirty patients had cutaneous melanoma with metastases and 1 patient had ocular melanoma with metastases. Eight patients had received prior chemotherapy. RESULTS: Of the 30 evaluable patients with cutaneous melanoma, 6 achieved a partial response, for an overall response rate of 20% (95% confidence interval, 7-38%). There was no response in the patient with ocular melanoma. Major sites of response include the adrenal gland, lung, tonsil, and cutaneous/subcutaneous tissues. Three patients had a prolonged duration of response lasting > or = 12 months. Side effects generally were mild and tolerable. Grade 3 or 4 hematologic toxicity occurred in 26% and 13% of patients, respectively. Nonhematologic toxicity included mild fatigue, paresthesia, and local arm discomfort from infusion. CONCLUSIONS: Weekly intravenous vinorelbine tartrate plus daily oral tamoxifen appears to be active in the treatment of patients with malignant melanoma. Further clinical trials in malignant melanoma patients treated with vinorelbine tartrate and tamoxifen appear warranted.

Administration, Oral↗
PubMed2000

Physico-chemical characterization of a novel tricyclic beta-lactam antibiotic.

GV118819X, a novel tricyclic beta-lactam antibiotic of GlaxoWellcome, is a racemic mixture of two diastereoisomers, A and B. Of the two diastereoisomers, only A is available as a pure compound. By analyzing mixtures of GV118819X and A, a partial phase diagram is constructed, which indicates the presence of a eutectic when the A fraction is approximately 39%. Moreover, the melting enthalpies of the eutectic mixture and of diastereoisomer B can be estimated. With the exception of the pure A form, all mixtures undergo important modifications in morphology and microstructure as a consequence of thermal treatments, which induce melting/amorphization of the eutectic, and crystallization of the A form. Analyses of the sieved fractions of GV118819X demonstrate that it consists of acicular crystals of different composition, with the larger crystals having a larger A fraction than the smaller ones. Grinding causes melting/amorphization of the eutectic and, following hours-long treatments, the formation of a substantial fraction of submicron particles with unusually low melting temperatures.

Anti-Bacterial Agents↗
PubMed1999

Update on mechanical revascularization in acute myocardial infarction: which role and when?

Mechanical revascularization in the acute myocardial infarction by primary angioplasty has several advantages over thrombolytic therapy. The short-term patency rates of the infarct-related artery range from 95 to 99% and a normal flow is achieved in more than 90% of the cases. This prompt and effective reperfusion is probably responsible for the improved prognosis with primary angioplasty. The better outcome after primary angioplasty is observed both in low- and in high-risk patients, in all ages and in patients presenting late (>6 h) after the chest pain. Pooled analysis of randomized studies, show that primary angioplasty as compared to thrombolysis, has a lower incidence of death, stroke and reinfarction. Additional advantages of primary PTCA include the possibility of reperfusion in patients in whom lysis is contraindicated or less effective (e.g. patients in cardiogenic shock, or with prior coronary artery bypass surgery) and the ability to provide prognostic information helpful in the patient triage. Thus, primary PTCA results in better outcome than thrombolysis when performed in centers with success rates comparable to those achieved in the randomized trials. Further studies are still needed to assess its long-term efficacy. Several randomized trials are underway to assess the role of stents and the use of more potent antiplatelet drugs, as the GPIIb/IIIa receptor blockers, in adjunct to balloon angioplasty in the treatment of acute myocardial infarction.

Angioplasty, Balloon, Coronary↗
PubMed1999

Starvation in yeast increases non-adaptive mutation.

The frequency of reversion in a histidine-requiring mutant of Saccharomyces cerevisiae increases about ten-fold in stationary cells during histidine starvation. Histidine starvation enhances a similar frequency of reversion in a tryptophan-requiring mutant. Starvation, therefore, enhances mutation frequencies in a non-adaptive manner. The base analogue 6-N-hydroxylaminopurine (HAP) added prior to plating on medium with limited histidine strongly increases reversion of the histidine mutant. HAP-induced reversion increases further in stationary starving cells with the same kinetics as that which increases spontaneous reversion. Adding HAP to the stationary starving cells does not produce any effect.

Adenine↗