Anatomy of a microearthquake sequence on an active normal fault.

The analysis of similar earthquakes, such as events in a seismic sequence, is an effective tool with which to monitor and study source processes and to understand the mechanical and dynamic states of active fault systems. We are observing seismicity that is primarily concentrated in very limited regions along the 1980 Irpinia earthquake fault zone in Southern Italy, which is a complex system characterised by extensional stress regime. These zones of weakness produce repeated earthquakes and swarm-like microearthquake sequences, which are concentrated in a few specific zones of the fault system. In this study, we focused on a sequence that occurred along the main fault segment of the 1980 Irpinia earthquake to understand its characteristics and its relation to the loading-unloading mechanisms of the fault system.

Leg muscle atrophy in idiopathic congenital clubfoot: is it primitive or acquired?

PURPOSE: To investigate whether atrophy of the leg muscles present in congenital clubfoot (CCF) is primitive or secondary to treatment of the deformity. METHODS: Magnetic resonance imaging (MRI) of both legs was taken in three cohorts of patients with unilateral congenital clubfoot (UCCF): eight untreated newborns (age range 10 days to 2 weeks); eight children who had been treated with the Ponseti method (age range 2-4 years); eight adults whose deformity had been corrected by manipulation and casting according to Ponseti, followed by a limited posterior release performed at age 2-3 months (age range 19-23 years). All of the treated patients wore a brace until 3 years of age. Muscles were measured on transverse MRI scans of both legs taken midway between the articular surface of the knee and the articular surface of the ankle, using a computer program (AutoCAD 2002 LT). The same program was used to measure leg muscles in the histologic cross sections of the legs of two fetuses with UCCF, spontaneously aborted at 13 and 19 weeks of gestation, respectively. Measurements of the whole cross section of the leg (total leg volume: TLV), of the muscular tissue (muscular tissue volume: MTV), and of the adipose tissue (adipose tissue volume: ATV) of the tibia, fibula, and of the other soft tissues (tendons, nerves, and vessels) were taken by using an interactive image analyzer (IAS 2000, Delta System, Milan, Italy). RESULTS: Marked atrophy of the leg muscles on the clubfoot side was found in both fetuses and untreated newborns, with a percentage ratio of MTV between the normal and the affected leg of 1.3 and 1.5, respectively. Leg muscle atrophy increased with growth, and the percentage ratio of MTV between the normal and the affected leg was, respectively, 1.8 and 2 in treated children and adults. On the other hand, fatty tissue tended to increase relatively from birth to adulthood, but it could not compensate for the progressive muscular atrophy. As a result, the difference in TLV tended to increase from childhood to adulthood. CONCLUSIONS: Our study shows that leg muscular atrophy is a primitive pathological component of CCF which is already present in the early stages of fetal CCF development and in newborns before starting treatment. Muscular atrophy increases with the patient's age, suggesting a mechanism of muscle growth impairment as a possible pathogenic factor of CCF.

Clinical characteristics and genotype analysis of patients with cystic fibrosis and nasal polyposis.

The prevalence of nasal polyps in a group of paediatric patients with cystic fibrosis was prospectively studied in comparison with a control group with cystic fibrosis but without polyps. Clinical variables, including pulmonary function tests, skin testing and mucociliary transport, were carried out in both groups, as well as genotype analysis. Endoscopic intranasal evaluation identified polyps in 29 of 89 patients (33%). Statistical analysis revealed that patients with nasal polyposis had better pulmonary function, a higher rate of Pseudomonas aeruginosa colonization, more hospitalizations, and more prevalence of allergy to Aspergillus fumigatus than did the comparison group. We found no statistically different genotype distribution between the polyposis and the control group. However, it can be emphasized that the prevalence of the compound heterozygous genotype is higher in the nasal polyposis group than in controls. Our observations suggest that other genetic and environmental factors could play an important role in the development of nasal polyposis.

[Computer-based preoperative planning for breast reconstruction in the woman with unilateral breast hypoplasia]. / Pianificazione computerizzata per la ricostruzione mammaria in donne affette da ipoplasia mammaria unilaterale.

BACKGROUND: Aim of this paper is to describe a computer program which can provide objective and quantitative data useful for the selection of the proper implant in order to obtain the symmetry with the contralateral breast in case of unilateral breast reconstruction by tissue expansion, especially for the surgeon without experience or for the occasional operator. METHODS: Our C++ program provides the final implant volume using the measurements of the semi-circumference and projection of the contralateral breast performed on the supine patient. The aim is the symmetry of the two breasts. RESULTS: According to our experience in breast reconstruction by tissue expanders, this program allows non invasive and simple measurements of the breast volume, useful to obtain the mammary symmetry. CONCLUSIONS: In case of breast reconstruction by tissue expansion, the preoperative evaluation is usually based on the surgeon's experience and on empirical observations without knowing the correct volume to reach. For this reason our program is useful to know the necessary volume for breast reconstruction, and therefore it allows the surgeon to obtain a better plastic result.