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Biomedical subjects

P Petrini

Publications and source records attributed to P Petrini.

48 records · Page 3Linked to original sources
PubMed1991

The epidemiology of fractures of the proximal end of the femur. Change in the incidence among the population at risk in the city of Perugia, Italy between the periods 1975-77 and 1986-88.

The current interest in the epidemiology of fractures of the proximal end of the femur stems from a constant rise in their incidence in Western countries over the past several decades. Many authors believe the explanation could be an increased specific risk factor as well as an aging population. In the city of Perugia, Italy between 1975-77 and 1986-88 the incidence of these fractures increased by 108%, although the number of residents over 60 years of age increased by only 25%. An especially remarkable increase was seen in women over 70 and in intertrocherantic fractures. This information together with the National Institute of Statistics' (ISTAT) demographic forecasts regarding the aging Italian population lead to alarming epidemiologic projections for the next several decades. We propose two possible explanations for this increased risk factor: an increase in the frequency of falls suffered by elderly people and a deterioration in the quality of their bone.

Accidental Falls↗
PubMed1990

Diagnostic symptoms of severe and moderate haemophilia A and B. A survey of 140 cases.

With a view to the characterisation of presenting symptoms, a survey was made of 140 boys diagnosed as having haemophilia A or B, severe or moderate form, in Sweden during the years 1960-1987. Mean age at diagnosis was nine months for the severe cases and 22 months for the moderate cases. Although the heredity was known in 59/140 cases, 35 had had bleeding episodes before diagnosis had been established, thus emphasising the importance of genetic information and carrier identification in haemophilia families. Of the presenting symptoms, subcutaneous bleedings constituted 41% while joint and muscle bleedings were uncommon; 16% were bleedings in conjunction with puncture of vessels, injections or surgery. Fourteen percent had anaemia and received blood-transfusion at diagnosis; 9% were diagnosed post-neonatally but 20% had shown abnormal bleeding tendency already in the neonatal period; seven boys (5%) had intracranial haemorrhages, five of them neonatally. A thorough family history and an extensive investigation of bleedings in the neonatal period should make early diagnosis possible.

Hemophilia A↗
PubMed1990

Homozygous protein C deficiency in two siblings.

Homozygous protein C (PC) deficiency is reported in two siblings (girl and boy) who received their proper diagnoses at the ages of 7 4/12 and 1 3/12 years respectively. The girl had perinatal asphyxia without bleeding. At 1 year of age she developed purpura fulminans. Treatment with heparin and plasma was successful. At 7 4/12 years she developed tender, bluish nonnecrotic skin changes after an orthopedic operation. The PC level was 0.08 U/ml. The boy had had a large intraventricular hemorrhage neonatally and developed severe brain damage. At 1 3/12 years he manifested the same skin changes as his sister and was treated similarly. The PC level was 0.05 U/ml. Both children now receive warfarin continuously and are essentially free of symptoms. The cases represent homozygous phenotypes in a family with a recessive trait of PC deficiency without thrombotic disease. The cases also show that severe PC deficiency may be compatible with life beyond infancy without any specific therapy.

Blood Transfusion↗
PubMed1986

Neuroendocrine effects of setoperone: a new neuroleptic drug.

Setoperone (R 52245), a serotonin S2 and dopamine D2 receptor blocker, was tested on eight healthy male volunteers, receiving 5 or 40 mg orally, in order to assess the modifications of plasma prolactin levels, as an index of receptor blocking activity. Both doses significantly increased plasma levels, confirming the dopamine blocking activity. In vitro and in vivo studies have shown serotonin S2 receptor blockade and lysergic acid diethylamide antagonist activity. Setoperone is proposed as a possible new neuroleptic drug.

Adolescent↗
PubMed1976

Three years of bacteriological monitoring in the Department of Paediatric Surgery.

The results of three years of bacteriological monitoring in the Department of Paediatric Surgery at the Ospedale Maggiore Ca'Granda in Milan are reported. The tests carried out involved the patients (faeces, urine, and pus cultures), the environment (operating theatre, incubators), and healthy carriers (upper respiratory tract of nursing and paramedical staff). The aetiopathogenesis of the post-operative infectious complications that occurred in 1974-1975 was investigated with the aid of surveys of the causative pathogens, the type of the surgical interventions, the atmospheric pollution in the operating theatre (mean indicative values), the number of operations per month, and the frequency of positive findings among the carriers. As a parallel investigation, between 1971 and the time of writing of this report the authors monitored the resistance to gentamicin of bacteria belonging to the family Pseudomonadaceae isolated from patients, in view of the constant threat posed by the vicinity of the burns department.

Bacterial Infections↗
PubMedDate not supplied

Linear poly(ethylene oxide)-based polyurethane hydrogels: polyurethane-ureas and polyurethane-amides.

Over the last 30 years, water-swellable and water-insoluble hydrogels have been extensively investigated and developed, leading to a large family of materials which have found uses in a wide range of biomedical applications. While hydrogels usually present a crosslinked structure, linear polyurethane-ureas (PUUs) based on poly(ethylene oxide) have been shown to be able to absorb and swell with aqueous media without dissolving. This behavior is due to the phase separated domain morphology, where hydrogen bonded urethane/urea hard segment domains are dispersed in a PEO soft segment domain. This work investigates the possibility of obtaining linear poly(ethylene oxide)-based polyurethane-amide (PUA) hydrogels using two amide diols as chain extenders, a mono amide diol (AD) and a diamide diol (DD), and a dicarboxylic acid (maleic acid, MA). Poly(ethylene oxide) based PUAs were obtained using a "one-shot" bulk polymerization technique. The chemicophysical characterization and water-solubility tests showed that these materials, while having molecular weights similar to the PUUs, do not possess sufficient phase separation, hydrogen bonding and hydrophobicity of the hard segment domains to exhibit hydrogel behavior. Crosslinked PUAs using maleic acid as chain extender show interesting hydrogel properties.

Journal Article↗
PubMedDate not supplied

Silk fibroin-polyurethane scaffolds for tissue engineering.

Silk fibroin (SF) is a highly promising protein for its surface and structural properties, associated with a good bio- and hemo-compatibility. However, its mechanical properties and architecture cannot be easily tailored to meet the requirements of specific applications. In this work, SF was used to modify the surface properties of polyurethanes (PUs), thus obtaining 2D and 3D scaffolds for tissue regeneration. PUs were chosen for their well known advantageous properties and versatility; they can be obtained either as 2D (films) or 3D (foams) substrates. Films of a medical-grade poly-carbonate-urethane were prepared by solvent casting; PU foams were purposely designed and prepared with a morphology (porosity and cell size) adequate for cell growth. PU substrates were coated with fibroin by a dipping technique. To stabilize the coating layer, a conformational change of the protein from the alpha-form (water soluble) to the beta-form (not water soluble) was induced. Novel methodology in UV spectroscopy were developed for quantitatively analyzing the SF-concentration in dilute solutions. Pure fibroin was used as standard, as an alternative to the commonly used albumin, allowing real concentration values to be obtained. SF-coatings showed good stability in physiological-like conditions. A treatment with methanol further stabilized the coating. Preliminary results with human fibroblasts indicated that SF coating promote cell adhesion and growth, suggesting that SF-modified PUs appear to be suitable scaffolds for tissue engineering applications.

Journal Article↗
PubMedDate not supplied

Factor IX inhibitors and anaphylaxis in hemophilia B.

PURPOSE: We present clinical and laboratory data on 18 children from 12 hemophilia treatment centers in the United States, Canada, and Europe with the purpose of disseminating information regarding a recently recognized, potentially life-threatening complication of treatment in very young children with hemophilia B. PATIENTS AND METHODS: Twelve hemophilia centers from the United States, Canada, and Europe provided clinical information and laboratory data concerning 18 children who had severe allergic reactions to infused factor (F) IX in close association with the development of an inhibitor to FIX. Laboratory testing for establishment of the diagnosis of hemophilia B and inhibitor to FIX was done locally at the centers treating these patients. FIX gene analysis was performed at one of six molecular genetics institutes. RESULTS: All 18 children had severe hemophilia B, and in each an inhibitor antibody to FIX developed. The median age at the time of anaphylaxis (or anaphylactoid reaction) was 16 months, and the median number of exposure days to FIX was 11. The FIX inhibitor was detected almost simultaneously with the first occurrence of anaphylaxis in 12 of 18 patients. Maximum inhibitor titers were 4.5-600 Bethesda units (BU), with a median titer of 48 BU. FIX gene analysis, performed in 17 of 18 patients, demonstrated complete deletion of the FIX gene in 10 and major derangements in seven. Immune tolerance induction (ITI) regimens have been attempted in 12 patients, with generally poor responses. Two of the 12 experienced nephrotic syndrome while on ITI. Recombinant FVIIa has been successfully used to treat bleeding episodes in 11 of these children. CONCLUSION: Physicians treating young children with hemophilia B should be aware of the potentially life-threatening complication of anaphylaxis. Children with complete gene deletions or major derangements of the FIX gene appear to be at greater risk. Those identified by genotype as being at greater risk may need to receive their first 10-20 treatments in a medical facility equipped for handling such emergencies. Recombinant FVIIa, although not licensed for use in the United States, appears to be the most suitable treatment option for bleeding episodes in such patients.

Anaphylaxis↗
PubMedDate not supplied

Factor VIII inhibitors in two families with mild haemophilia A: structural analysis of the mutations.

The development of inhibitory antibodies against coagulation factor VIII (FVIII) in patients with mild haemophilia A is uncommon. We describe here two families in which three or two members have developed inhibitors, suggesting a familial predisposition. The mutations found, in the A2 (Arg593Cys) and C1 domains (Tyr2105Cys), have been reported to give rise to inhibitor development in single individuals in addition to the family cluster we describe, strongly suggesting that these amino acid substitutions give rise to a more immunogenic protein. The analysis of structural models of activated factor VIII revealed that Arg593 is solvent-exposed and involved in a network of electrostatic interactions while Tyr2105 is partially buried and has hydrophobic interactions essentially with Ile2144. All these residues are strictly conserved in the FVIII amino acid sequence from man, pig and mouse, suggesting, at least, that they have structural roles. We propose that the two mutations in these families could cause mild haemophilia A because they induce local conformational changes (and possible secretion or intermolecular interaction problems, e.g., with von Willebrand factor) compatible with immunogenicity and production of inhibitors against the infused wild-type FVIII.

Age of Onset↗