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Biomedical subjects

M Beretta

Publications and source records attributed to M Beretta.

At least 19 recordsLinked to original sources
PubMed2005

Expression studies on a novel type 2B variant of the von Willebrand factor gene (R1308L) characterized by defective collagen binding.

A novel mutation, R1308L (3923G > T) was present in the heterozygous state in five members of a family with type 2B von Willebrand disease (VWD) characterized by a full set of von Willebrand factor (VWF) multimers in plasma and by the absence of thrombocytopenia before and after desmopressin (DDAVP). The defect (R1308L) was located at the same amino acid position of one of the most common mutations associated with type 2B VWD (R1308C), which is characterized by the loss of high molecular weight VWF multimers (HMWM) in plasma and the occurrence of thrombocytopenia. To understand the mechanisms of this defect, the novel (R1308L) and 'common' (R1308C) mutations were expressed in COS-7 cells, either alone or, to mimic the patients' heterozygous state, together with wild-type VWF. R1308L recombinant VWF (rVWF) had a higher affinity for the platelet glycoprotein Ibalpha (GPIbalpha) receptor than wild-type rVWF, R1308C rVWF showing an even higher affinity. A novel finding was that both mutant rVWFs showed a similarly reduced binding to collagen type I and type III in comparison with wild-type rVWF. The latter finding suggests a more important role than recognized so far for the VWF A1 domain in VWF binding to collagen, which may contribute to the in vivo hemostatic defect associated with type 2B VWD.

Adult↗
PubMed2003

Treatment of metastatic malignant melanoma with dacarbazine plus tamoxifen, or vindesine plus tamoxifen: a prospective randomized study.

This study aimed to verify whether the advantage in terms of response rate and survival of dacarbazine plus tamoxifen over dacarbazine alone in metastatic malignant melanoma reported in a previous randomized trial was due to a specific interaction of dacarbazine with tamoxifen. A total of 125 patients with locoregional or disseminated malignant melanoma were randomized to receive dacarbazine (250 mg/m(2) days 1-5 every 3 weeks) plus tamoxifen (arm A) or vindesine (3 mg/m(2) every week for 6 weeks, then every 2 weeks) plus tamoxifen (arm B). Of the 125 randomized patients, 57 and 59 were evaluable in arm A and B, respectively. The complete response rates were the same (2% versus 2%) and the complete plus partial response rates were similar (11% versus 14%) in the two groups. There was no significant difference in survival. Neither response or survival correlated with gender. In conclusion, when combined with tamoxifen, dacarbazine does not have a specific effect on response or survival compared with vindesine. The lower response rate to dacarbazine plus tamoxifen (11%) than that reported in the previous trial (28%) might be explained by actual differences in patient and/or participating centre accrual characteristics in the presence of apparently identical eligibility criteria.

Adult↗
PubMed2000

Epidemiological relationships between Aeromonas strains isolated from symptomatic children and household environments as determined by ribotyping.

Ribotyping was used to study the epidemiology of Aeromonas associated gastro-enteritis in young children. Ribotyping patterns of 29 Aeromonas strains (16 Aeromonas caviae, 8 Aeromonas hydrophila, 3 Aeromonas eucrenophila, 1 Aeromonas veronii, and 1 Aeromonas encheleia) isolated from primary stool cultures of sick children were compared using the GelCompare software with patterns of 104 strains (39 Aeromonas eucrenophila, 29 Aeromonas caviae, 11 Aeromonas encheleia, 10 Aeromonas hydrophila, 6 Aeromonas bestiarum, 3 Aeromonas veronii, 3 Aeromonas popoffii and 3 Aeromonas media) isolated from their household environment in order to investigate the route of transmission of these bacteria. Fifteen strains (approximately 47%) isolated from stool cultures of patients showed the same riboprofile as strains found in contacts or environment. In particular, three strains isolated from patients shared the same riboprofile with strains found in their domestic environment. The wide diffusion of potentially pathogenic Aeromonas strains in our household samples, and the high rate of asymptomatic carriers among family members, suggested that predisposing factors of the host could make children prone to an Aeromonas-related intestinal disease.

Aeromonas↗
PubMed2000

At the source of western science: the organization of experimentalism at the Accademia del Cimento (1657-1667).

The Accademia del Cimento, founded by the Medici princes, Ferdinando II, Grand Duke of Tuscany, and his brother, Leopoldo, later Cardinal, had members and programmes of research very different from earlier academies in Italy. The Cimento foreshadowed later European academies and institutions specifically devoted to research and improvement of natural knowledge. It issued only one publication, the Saggi di naturali esperienze, and most of the observations and experimental results from its brief life remain unpublished. The Roman Accademia fisica-matematica, associated with Queen Christina of Sweden, continued to some extent its emphasis on experiment, while The Royal Society, with which it maintained links, placed even greater reliance on experiment and its validation through unvarnished publication. Comparisons between the Cimento and its contemporaries, The Royal Society and the French academy, illuminate the origin of scientific institutions in the early modern period.

Europe↗
PubMed1999

Results and side effects of dermatologic radiotherapy: a retrospective study of irradiated cutaneous epithelial neoplasms.

BACKGROUND: Ionizing radiation therapy has a well-defined role among several therapeutic options available for the management of cutaneous neoplasms. However, many dermatologists today are not aware of its potential. OBJECTIVE: Our purpose was to evaluate the effectiveness and safety of radiotherapy in a large series of patients with primary malignant epithelial neoplasms (PMENs), who had been subjected to radiotherapy between 1982 and 1995. METHODS: A retrospective study was performed on 1188 patients with a total of 2002 PMENs that had been treated by contact, superficial, and intermediate x-ray therapy. RESULTS: Complete remission was obtained in 98.7% of the irradiated lesions. The 5-year cure rate was 90.73%. Cosmetic results were evaluated as "good" or "acceptable" in 84.01% of the treated lesions. Acute complications occurred in 1.94% and chronic complications in 0.34%. To date, neither radio-induced skin neoplasms nor late stochastic effects have been observed. CONCLUSION: This study confirms that dermatologic radiotherapy is an effective and reliable form of treatment of PMENs and has a favorable cure rate/toxicity ratio.

Adult↗
PubMed1997

The "round block" purse-string suture: a simple method to close skin defects with minimal scarring.

We report the use of a subcuticular purse-string suture for closure of surgical skin defects, a simple maneuver that we have found to be very useful in closing difficult wounds and reducing scarring. The purse-string suture is performed with a large nonabsorbable suture that is passed intradermally and left in situ at least 4 weeks. This technique has been applied in 196 patients for a total of 221 sutures over a period of 2 years, being used to close skin defects from 2 x 2 to 8 x 11 cm in many areas of the body. All the patients showed, at closure, a large number of concentric redundant folds as well as considerable distortion of nearby structures; both improved impressively over a period of 2 to 3 weeks and became nearly normal at the time of suture removal (4 to 8.2 weeks, mean 5.7 weeks). The initially very limited and almost circular scar oriented itself along the skin tension lines over a period of a few weeks and, when matured, was always shorter than the original defect. In general, minimal scar widening occurred when we used larger sutures (more than 0-1) that were left longer (more than 6 weeks). Complications have been 23 cases of dehiscence (10.4 percent) in 23 patients (between the fifth and sixteenth days, mean 6.7 days); they were caused by the bad quality of the skin and by the use of too small sutures that cut through the dermis. The "round block" suture has many advantages: 1. It is a simple, inexpensive, and rapid technique for closing wounds by expanding the surrounding skin and often avoiding the use of skin grafts and/or local flaps. 2. It can minimize scarring; the final scars are shorter than the original defect and usually of very good quality. 3. It allows a very useful temporary closure that stretches the surrounding skin while waiting for the definitive histologic report. If this method is not chosen as a definitive closure, later repair with local flaps may be facilitated. 4. For the reasons expressed above, it never compromises the final result even in cases of dehiscence. The main disadvantage is the acceptability of the method on the part of patients, who need to be carefully prepared for both the gross initial distortion and the long time the suture has to be retained; nevertheless, patient satisfaction with the final results in generally very high, especially in large excisions of the face.

Adolescent↗
PubMed1997

Intracavitary contact X-ray therapy of oral HIV-associated Kaposi's sarcoma.

A retrospective study was performed to assess the efficacy and low mucosal toxicity of intracavitary contact X-ray therapy (ICRT), a proposed treatment of small/medium sized lesions of oral HIV-associated Kaposi's sarcoma (HIV-KS). Twenty-six patients with histologically confirmed oral HIV-KS underwent ICRT in the period 1986-1995. No patient received antiblastic or interferon therapy during the radiotherapy or follow-up periods. ICRT was performed according to the usual technical modalities of contact X-ray therapy, but the end of the source of ionizing radiations was introduced into the oral cavity. The total doses administered ranged from 10 to 50 Gy per field, in one or two weekly fractions of 5 Gy each. The follow-up ranged from 1 to 44 months (mean 7.5 months). Complete remission was obtained in 20 cases (76.92%), partial remission in 6 (23.08%) and relapse in one case (3.84%). Pain was relieved in all cases. Mucosal reaction was mild and did not result in any interruption of treatment. Our data suggest that ICRT is an effective and well tolerated treatment. It can be used in the management of oral HIV-KS instead of external radiotherapy, provided that the size and the location of the lesions and the conformation of the palate are suitable to this technique.

AIDS-Related Opportunistic Infections↗
PubMed1996

Use of a versatile axial dorsonasal musculocutaneous flap in repair of the nasal lobule.

We present our 17 years of experience in using a sliding axial musculocutaneous flap from the nasal dorsum in the repair of 53 nasal lobular defects (follow-up 3 to 212 months, mean 47.3 months). This flap is a modification of the classic Rintala flap but is based on a greater understanding of surgical anatomy, the biomechanical properties of skin, and physiology of flaps, all of which allow a more aesthetically satisfactory closure of very distal nasal lobular defects. After excising the tumor, two parallel incisions are made along the sides of the nasal dorsum, and flap is raised in the gliding plane deep to the fibromuscular layer of the nose and superficial to the cartilage and bone and then advanced over the defect, which can be as large as the entire nasal lobule. The flap is very reliable (no failure in our series) and easy to perform; furthermore, it is a fast, one-step reconstructive procedure that leaves the scars in areas of natural shadow. This flap makes use of a wide dorsal and glabellar undermining to recruit sufficient skin; it takes advantage of the mild tension exerted by the underlying nasal framework to lengthen the flap reliably without the need for an extra incision or Burow's triangles, as originally described by Rintala. Neither tip rotation nor glabella flattening has ever been found to be a real problem in our series because the flap elongates in a period of 2 to 6 weeks and tip always comes down, provided that the nasal framework is not modified. We believe that the axial musculocutaneous sliding flap has distinct advantages over other alternative local flaps in the repair of lobular nasal defects; moreover, although this simple operation cannot compete with the quality of the aesthetic results achieved by very skilled masters using frontal flaps, it is an easy, quick, one-step procedure that allows acceptable and reliable aesthetic results to be achieved by the majority of surgeons, and it does not harm the precious forehead donor site, which may become essential in case of the need for further reconstruction.

Aged↗
PubMed1995

Iatrogenic nostril stenosis: aesthetic correction using a vestibular labial mucosa flap.

Nostril stenosis is an infrequent finding that often has an iatrogenic cause. It is a very difficult problem to resolve and usually requires several months of prosthetic support in order to counteract the recurrence of internal scarring and shrinking. We present a 4-year-old child with a monolateral iatrogenic nostril stenosis. A satisfactory and stable correction was obtained using a "piercing" flap taken from the labial vestibule. The use of a nasal stent (not placed immediately and worn only at night) was necessary for only 2 months. This technique has a number of advantages: the absence of external scars, little or no tendency to recurrence due to the absence of contraction provided by the well-vascularized flap tissue, and the ease and rapidity of the surgical procedure.

Child, Preschool↗
PubMed1994

Codon usage and evolutionary rates of proteins.

The 61 codons and the three terminators were counted in the coding sequences of 31 families of proteins of higher vertebrates. The protein families were ordered according to their evolutionary rate. In each family, the ratio between the Observed and Expected frequency of each codon was obtained (O/E ratio). A strong and significant positive correlation was observed between the O/E ratio of the eight codons AAC, TAT, ATA, GAA, ACA, AAT, ATG and CGA and the evolutionary rate of the protein. A negative and significant correlation was observed for codons AAG and GAG. It was advanced that the functional constraints of proteins can influence the usage of codons, particularly for those trimers which are components of signal sequences. It was also observed that the O/E ratios of the terminators are negatively correlated with the evolutionary rate of the protein they terminate, and the correlation is significant for TAA and TGA, which in vertebrates might be older than TAG.

Animals↗
PubMed1994

Identification of a set of frequent decanucleotides in plants and in animals.

We studied the frequency distribution of 1,048,576 oligonucleotides 10 bp long in a sample of 1.961 Mbase of genes from plants, made of 635 sequences extracted from GenBank 71.0, with the aim of detecting transcription control signals. Among all decamers, 3255, or 0.3%, had a frequency 10 times higher than the mean and were subjected to further statistical analysis. For each of the 3255 decamers (parents), we counted the individual frequencies of the 30 decamers (progeny) differing from the parent by one base mutation, and calculated two variance/mean chi-squares for the progeny, with and without the parent decamer. By studying the distribution of the ratio between the two chi-squares we observed that out of 3255 decamers > 10 times frequent than average, 432 had a chi-square ratio > 1.9. In this residual set, which corresponds to < 0.04 per cent of all possible decamers, only 15 known eukaryotic transcription control elements were found; on the other hand, it included 29 decanucleotides that matched with decanucleotides of a set of Drosophila, 24 with a set from mammals, 13 with a set from yeast and four with a set of viruses--all sets identified with the statistical procedures here described. These decanucloetides are highly repetitive and seem to be present throughout all higher organisms, whereas they are uncommon in mammalian viruses.

Animals↗
PubMed1994

[Transperitoneal nephrectomy of crossed ectopic kidney without fusion associated with stenosis of the pyeloureteral junction and pyelocaliceal staghorn calculi].

The authors report their experience on a case of crossed ectopic kidney without fusion associated with stenosis of the pyeloureteral junction and secondary pyelocaliceal staghorn calculosis. After a brief summary of the various types of kidney ectopia and related principles of operation they describe their case report underlying the rarity of their case and the surgical approach. They consider the anterior transperitoneal approach as the most indicated for this type of malformation as it permits a better surgical view of the kidney and of the vascular structures.

Adult↗
PubMed1993

Comparison of structures from frequencies of genes and surnames in the population of Ferrara.

The genetic structure based on isonymy and on gene frequencies of 7 enzyme systems was studied in a sample of 1361 individuals residing in the Ferrara Province in the Po delta (northern Italy). The sample was divided into two subsamples. The first, or indigenous, sample (n = 885) was composed of persons born and residing in the same commune of the province; the second, or migrant, sample (n = 476) was composed of persons who immigrated from a different commune. The study of the seven polymorphic genetic systems shows that there is no significant difference in gene and genotype frequencies between the two subsamples. On the other hand, the migration indicator derived from isonymy of family names is significantly larger in the migrant group than in the indigenous group. Isonymy techniques permit the detection of recent migration even under equality of gene frequencies.

Consanguinity↗
PubMed1992

Genetic structures in the Po Delta: principal components, systemic functions and the relative age of the beta-thalassemia polymorphism.

The principal component representations of the genetic structure of the human population of the Po Delta, obtained from 7 polymorphic loci, are compared with the representations obtained from the systemic function of gene frequencies devised by Womble 1951. It is noted that, when tridimensional representations are used, some consistency is visible in the results of the two methods for the description of the genetic population structure in the area under study. Both methods indicate that the present structure of the balanced polymorphism for beta-thalassemia in the area appears to be more recent than the structure of the neutral polymorphisms studied.

Alleles↗
PubMed1992

The analysis of the joint effect of substances on reversion systems and the assessment of antimutagenicity.

The statistical methods for the analysis of mutagenicity and carcinogenicity underwent considerable theoretical-practical development following the need for assessing the mutagenic and carcinogenic potential of substances. Antimutagenicity is investigated through the analysis of respondents in dose-response assays, when two different molecules are administered separately and as a mixture to a respondent system. When the number of respondent units is high, and doses are orthogonal, it is possible to apply simple models such as analysis of variance. This is not always possible or common, and alternative approaches have been developed, based on multiple regression and on tables of proportions. In this work, some of the most frequently used methods for the assessment of joint responses are reviewed, particularly those based on multiple regression, such as the method of Shaeffer et al. and the method of Hass et al. In order to illustrate these methods, joint responses of perylene and cyclopentapyrene, of N-acetylcysteine and dinitropyrene, and of N-acetylcysteine and extracts from diesel exhausts were analyzed. An antagonistic effect of perylene on the action of CPP was detected by the algorithm of Shaeffer et al. The effect is not multiplicative, i.e., it is not proportional to the product of doses. The antimutagenic effect of N-acetylcysteine on dinitropyrene is multiplicative, as detected by the method of Hass et al. The latter reveals that the inhibition by N-acetylcysteine on the mutagenic effect of extracts from diesel exhausts is also multiplicative.

Acetylcysteine↗
PubMed1992

Genetic structures in the population of Veneto.

The genetic structures of the population residing in the provinces of Venice and Rovigo in the Veneto region at the north of the Po delta in Italy was studied in 1,210 individuals residing in 18 sampling areas, using the phenotype and gene frequencies of 7 red cell enzymes: acid phosphatase (ACP1), esterase D (ESD), glyoxalase I (GLOI), glutamic-pyruvic transaminase (GPT), 6-phosphogluconate dehydrogenase (6-PGD), phosphoglucomutase 1 (PGM1), and phosphoglycollate phosphatase (PGP). For the analysis of the distributions of phenotype and gene frequencies, standardized variance and kinship profiles were used. It was found that the genetic differentiation within each province is low, and that only two systems, GPT and PGP, are significantly different between the two provinces. The samples studied seem to belong to a mainly homogeneous population.

Erythrocytes↗