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Biomedical subjects

Luigi Martinelli

Publications and source records attributed to Luigi Martinelli.

8 recordsLinked to original sources
PubMed2006

Effects of physical training on cardiovascular control after heart transplantation.

BACKGROUND: Exercise performance in heart-transplanted patients increases with respect to pre-transplantation but remains subnormal, and it does not improve with time after surgery. Possible causes include persisting denervation, and sympathetic vasoconstriction inducing functional vascular abnormalities that prevent adequate increase in blood flow to the exercising limbs. We tested the effects of physical training on baroreceptors-mediated control of heart rate and blood pressure in recently heart-transplanted subjects. METHODS: Patients were randomly allocated to physical training (n=13, 30 min cycling at 60-70% of peak oxygen consumption for 5 days/week for 6 months) or to control (n=11). Upright exercise test to exhaustion was performed at the beginning of the study after 3 and 6 months. Reflex changes in RR interval and blood pressure in response to sinusoidal neck suction (6 and 12 cycles/min 0 to -30 mm Hg swing) were considered as evidence of reinnervation and baroreflex control of blood pressure, respectively. RESULTS: After 6 months peak oxygen consumption (p<0.001), exercise time (p<0.01) and workload (p<0.01) increased in trained patients. Before training RR interval and blood pressure were not modified by neck suction. After physical training systolic (p<0.01) and diastolic blood pressure decreased, RR interval and blood pressure could be modulated (p<0.05) by slow (6 cycles/min) neck suction, indicating initial cardiac sympathetic reinnervation and restored sensitivity to autonomic modulation on the arteries. No changes were observed in controls. CONCLUSIONS: Physical training improved exercise performance and the control exerted by the autonomic nervous system through the sympathetic nerves at both cardiac and vascular level.

Adult↗
PubMed2006

Quantifying the Gurken morphogen gradient in Drosophila oogenesis.

Quantitative information about the distribution of morphogens is crucial for understanding their effects on cell-fate determination, yet it is difficult to obtain through direct measurements. We have developed a parameter estimation approach for quantifying the spatial distribution of Gurken, a TGFalpha-like EGFR ligand that acts as a morphogen in Drosophila oogenesis. Modeling of Gurken/EGFR system shows that the shape of the Gurken gradient is controlled by a single dimensionless parameter, the Thiele modulus, which reflects the relative importance of ligand diffusion and degradation. By combining the model with genetic alterations of EGFR levels, we have estimated the value of the Thiele modulus in the wild-type egg chamber. This provides a direct characterization of the shape of the Gurken gradient and demonstrates how parameter estimation techniques can be used to quantify morphogen gradients in development.

Animals↗
PubMed2005

[Endoscopic vein harvesting. Impact of learning curve on results and rehabilitation].

BACKGROUND: The tendency of modern surgery is towards the reduction of invasiveness. The aim of this study is to evaluate the impact of the learning curve, the reliability, the short term results and the advantages in terms of rapid rehabilitation of endoscopic vein harvesting (EVH) in a consecutive series of 20 patients operated on of aorto-coronary bypass surgery. METHODS: Between February and June 2005, 20 patients between 61 e 82 years of age underwent EVH with the use of Vasoview 5 (Guidant Corporation, Indianapolis, USA). To evaluate the impact of learning curve on the total operative time, patients were divided in 4 chronologically consecutive groups (G1, G2, G3, G4). Intraoperative characteristics and short term results were evaluated. RESULTS: The mean velocity and the mean time of harvesting in G4 were 0,68 cm/min and 45 min. respectively, similar to the time required for a scheletonized left internal mammary artery harvesting. In the first 5 patients 2 conversions were required, one of them related to the EVH technique. No bleeding, functional impairment or infective complications are reported. Active mobilization was possible in every case in the first post-operative day. CONCLUSIONS: EVH is a reliable technique and the learning curve can be limited to the first 5 cases. The foreseeble reduction of infectious complications, the absence of pain and the immediate mobilization of the leg allow a rapid and effective rehabilitation.

Age Factors↗
PubMed2003

Early closure of postinfarction ventricular septal defects.

BACKGROUND: According to the guidelines of the American College of Cardiology/American Heart Association early closure of postinfarction septal defects is now a class I indication although it still carries a relevant morbidity and mortality. The operative risk is related both to the critical hemodynamic conditions of the patient and to the technical difficulties posed by the friable tissue of the infarcted area. The most recent techniques involving the use of pericardial patches reinforced by acrylic glue have significantly reduced the hospital mortality. The aim of this study was to discuss the reliability of an aggressive, tissue-sparing surgical approach to this complication. METHODS: We present a consecutive series of 12 patients operated upon between January 1998 and October 2001 within 12 hours of the onset of clinical evidence of postinfarction septal rupture. Repair was achieved with minimal septal debridement and the use of a large pericardial patch reinforced by a biological glue. RESULTS: Three cases of dehiscence required early reoperation with no hospital mortality. CONCLUSIONS: This procedure is technically feasible and allows early aggressive treatment of postinfarction septal rupture with satisfactory results.

Aged↗
PubMed2002

Pulmonary valve lipoma presenting as syncope.

We report a case of a pulmonary valve lipoma presenting as syncope in a 28-year-old woman. Surgical excision of the mass was performed in urgency and the patient was discharged uneventfully.

Adult↗