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Biomedical subjects

S Ambrosi

Publications and source records attributed to S Ambrosi.

11 recordsLinked to original sources
PubMed2005

On the importance of anandamide structural features for its interactions with DPPC bilayers: effects on PLA2 activity.

The acylethanolamide anandamide (AEA) occurs in a variety of mammalian tissues and, as a result of its action on cannabinoid receptors, exhibits several cannabimimetic activities. Moreover, some of its effects are mediated through interaction with an ion channel-type vanilloid receptor. However, the chemical features of AEA suggest that some of its biological effects could be related to physical interactions with the lipidic part of the membrane. The present work studies the effect of AEA-induced structural modifications of the dipalmitoylphosphatidylcholine (DPPC) bilayer on phospholipase A2 (PLA2) activity, which is strictly dependent on lipid bilayer features. This study, performed by 2-dimethylamino-(6-lauroyl)-naphthalene fluorescence, demonstrates that the effect of AEA on PLA2 activity is concentration-dependent. In fact, at low AEA/DPPC molar ratios (from R = 0.001 to R = 0.04), there is an increase of the enzymatic activity, which is completely inhibited for R = 0.1. X-ray diffraction data indicate that the AEA affects DPPC membrane structural properties in a concentration-dependent manner. Because the biphasic effect of increasing AEA concentrations on PLA2 activity is related to the induced modifications of membrane bilayer structural properties, we suggest that AEA-phospholipid interactions may be important to produce, at least in part, some of the similarly biphasic responses of some physiological activities to increasing concentrations of AEA.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1999

[Diagnosis and treatment of a case of adenocarcinoma of the cervix in pregnancy].

The authors report a case of mucinous-papilliferous adenocarcinoma of the cervical canal in a pregnant woman. After performing three Pap tests which demonstrated the presence of normoconformate endometrial cells partly with a normal conformation and partly with nuclear atypia, the patient was monitored with periodical obstetric examinations. A neoformation of the portio was observed at week 28: differential diagnosis was made between a hypertrophic benign tumour and a well differentiated adenocarcinoma. The patient was monitored until birth and colposcopy was then performed with biopsy about one month later. Histological tests were positive for mucinous papilliferous adenocarcinoma. The patient underwent conisation with rotating loop and subsequently Piver 2 surgery owing to the suspected spread of the neoplasm beyond the margin of resection. The operative finding was negative and the patient is now free of disease.

Adenocarcinoma, Mucinous↗
PubMed1986

Percutaneous vs. totally implantable catheters in home parenteral nutrition.

The technique of the implementation of Home Parenteral Nutrition (HPN) is improving continuously so carrying minimum risk of technical complications and supplying maximum comfort for the patient. For example the HPN benefits of the recent availability of Ethil-Vinil-Acetate (EVA) bags that permit the contemporary administration of all nutrients, lipids included, and of infusion pumps which are lighter, safer and more versatile and which have rechargeable batteries. Some new types of completely implantable catheters with a subcutaneous reservoir present a better rationale compared with complications and with patient's compliance in respect of traditional percutaneous catheters used in HPN. We wanted to verify these presuppositions in a retrospective study with a completely implantable catheter, Port-A-Cath (PAC) Pharmacia, with a group of six patients already under HPN for a period of 901 patient-days with a percutaneous catheter. We compared the two methods of treatment after 1114 patient-days with the PAC. Concerning complications, we have three catheter related sepsis (3.3 1000 days) with percutaneous catheter and 1 sepsis (0.9 1000 days) with the PAC. We also had one catheter obstruction in a patient with the PAC implanted in the Inferior Vena Cava. All the patients accepted the new technique and even if they did not have the same motivation, all of them particularly appreciated the possibility of the avoidance of any external device. Our experience leads us to report that the Port-A-Cath system may be useful in long-term parenteral nutrition but other research is needed to confirm its rationale.

Journal Article↗
PubMed1985

Occult thyroid metastasis from untreated uveal melanoma.

A localized and asymptomatic metastasis from an untreated choroidal melanoma developed in the thyroid and was incidentally discovered by fine-needle aspiration biopsy. Since metastases from uveal melanoma usually are absent at the time of clinical diagnosis but occur much later in highly predictable sites, the finding of a distant blood-borne metastasis in such an early phase and in the thyroid is very unusual, as illustrated by a review of the literature.

Aged↗
PubMed1980

Sleep patterns in infants under continuous feeding from birth.

Continuous parenteral or enteral feeding of infants with major gastrointestinal problems (prolonged diarrhoeas, inflammatory digestive illnesses, anatomical anomalies necessitating surgical intervention, etc.) brings about a prolonged modification in nutritional and environmental conditions. The consequence of eliminating the feeding rhythms of the waking-sleeping rhythm in 16 infants between 1 and 8 months old were studied. In most of the infants the duration of sleep was close to that given by Kleitman in normals. Slightly decreased in 4 of the infants, these durations never showed significant differences from normative values. No delay was observed in the maturation of sleep patterns. The percentage and mean length of periods of quiet sleep were practically identical for all infants but a number of them showed large amounts of ambiguous sleep. The fact that none of these values evolved with age should be stressed. Paradoxical sleep periodicity was similar to that of normal infants, while the quiet sleep-paradoxical sleep cycles were shorter. In conclusion, the absence of feeding rhythms appeared not to modify greatly the sleep maturation and organization.

Cerebral Cortex↗
PubMedDate not supplied

The influence of age and sex on nutritional parameters in subjects aged 60 years and over.

The nutritional assessment of the elderly shows several interpretative difficulties due to the lack of standard parameters. Moreover chronic age-related diseases can interfere with the physiological nutritional status. Anthropometric (triceps skinfold, arm muscle area, total body muscle mass, fat mass and Body Mass Index (BMI)), biochemical (serum prealbumin, transferrin, ceruloplasmin, total protein and albumin) and immunological (serum lymphocytes) parameters were measured in 583 out-patients aged 60 years or over selected on the basis of clinical and biochemical criteria and with BMI </= 30. The subjects were classified into four age-groups (60-64, 65-69, 70-74, >/= 75) for each sex. The F-test analysis for all anthropometric parameters except BMI showed significant differences with respect to age (P < 0.05) and sex (P < 0.05). Among biochemical parameters, prealbumin showed a significant difference for age (P < 0.05) and sex (P < 0.05) (males, 30.3 +/- 8.2; females, 29.1 +/- 7.5) while ceruloplasmin showed a significant difference for sex only (P < 0.05) (males, 40.9 +/- 9.3; females, 43.8 +/- 8.2). When the biochemical mean values obtained in this study were compared with those utilized in the daily routine of the hospital central laboratory, ceruloplasmin and prealbumin resulted in significantly higher (P < 0.05) while total protein and albumin were significantly lower values (P < 0.05).

Journal Article↗