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Biomedical subjects

G Marino

Publications and source records attributed to G Marino.

At least 37 records · Page 2Linked to original sources
PubMed2003

Peroxynitrite-dependent modifications of tyrosine residues in hemoglobin. Formation of tyrosyl radical(s) and 3-nitrotyrosine.

Although peroxynitrite is believed to be one of the most efficient tyrosine-nitrating species of biological relevance so far identified, its nitration efficiency is nevertheless limited. In fact, the nitrating species formed through peroxynitrite decay are caged radicals ((*)OH/(*)NO(2) or, in the presence of carbon dioxide, CO(3)(*-)/(*)NO(2)) and the fraction that escapes from the solvent cage does not exceed 30-35%. One exception may be represented by metal-containing compounds that can enhance the formation of nitrotyrosine through a bimolecular reaction with peroxynitrite. Moreover, if the metal is also regenerated in the reaction, the compound is considered a nitration catalysts and the yield of tyrosine nitration enhanced several fold. Examples of peroxynitrite-dependent nitration catalysts are the Mn-superoxide dismutase, some cytochromes and several metalloporphyrins. On the contrary, it has been claimed that some hemoproteins are scavengers of peroxynitrite and play a role in limiting its biodamaging and bioregulatory activity. In this review, we discuss the case of hemoglobin, which is probably the major target of peroxynitrite in blood. This protein has been reported to protect intracellular and extracellular targets from peroxynitrite-mediated tyrosine nitration. This property is shared with myoglobin and cytochrome c. The possible mechanisms conferring to these proteins a peroxynitrite scavenging role are discussed.

Animals↗
PubMed2003

Low-density-lipoprotein peak particle size in a Mediterranean population.

BACKGROUND: The predominance of small, dense low-density lipoprotein (LDL) particles ('LDL phenotype B') has been associated with a three-fold increased risk of myocardial infarction, but the feasibility of the identification of small, dense LDL as independent predictors of coronary artery disease risk in population studies remains questioned. Design We evaluated the LDL peak particle size and its relation with other established risk factors for coronary heart disease in a group of 156 randomized subjects living on the Mediterranean island of Ustica (71 males and 85 women, range of age 20-69 years), representing approximately 30% of the total population. RESULTS: The prevalence of LDL phenotype B subjects was low (approximately 15% in both men and women) and there was a clear trend for both genders in reducing the LDL peak particle size with age. Moreover, LDL phenotype B subjects had higher BMI values, prevalence of diabetes and plasma triglyceride (TG) levels and lower plasma HDL-C concentrations in comparison with LDL phenotype A individuals; in a multivariate analysis, plasma TG levels were the only variable independently associated with LDL peak particle size. CONCLUSIONS: In this population, which appears to be somewhat protected by premature coronary artery disease, a low prevalence of the LDL pattern B was found in both men and women, and plasma TG could have a key role in regulating the LDL peak particle size. The follow up, still ongoing, will provide useful information on the predictive role of LDL peak particle size on cardiovascular risk, at least in a low-risk population.

Adult↗
PubMed2003

Method to express and purify nm23-H2 protein from baculovirus-infected cells.

High-throughput protein expression and purification are major bottlenecks in the postgenomic and proteomic era. We show here an automated method to express and purify nm23-H2, a nucleoside diphosphate kinase (NDPK), in a 96-well format, by the use of a robotic workstation, from insect Spodoptera frugiperda (Sf9) baculovirus-infected cells using nickel-nitrilotriacetic acid (Ni-NTA) agarose beads. The automated method is coupled to mass spectrometry for a validation and quality-control analysis. To verify the bona fide of the recombinant protein, several tests have been produced, including NDPK assay, Western blotting, and in vitro phosphorylation experiments, thus confirming the value of the protocol developed. The method has been validated for the expression of several proteins, thus confirming the value of this automated protocol. The research presented here is a useful method both for industrial and academic environments to produce in a high-throughput mode recombinant eukaryotic proteins to be assayed for a specific function in a systematic manner.

Animals↗
PubMed2003

[From molecular biology to new treatment approaches to colorectal cancer: basic research, experimental trials and surgical implications].

The Authors review the natural history of colorectal cancer from the point of view of molecular biology and genetics from aberrant crypts foci and familiar adenomatous polyposis to hereditary non polyposis colon cancer and sporadic colorectal cancer. They carry out international literature about basis knowledges, experimental trials and personal studies. Up to day traditional colorectal cancer surgical treatments and adjuvant or neoadjuvant pharmacological therapy cannot be modified, nevertheless "new drugs generation" known as signal transduction inhibitor could, in the future, prove to be an effective cancer treatment. The Authors highlight recent experimental clinical trials probably able to prevent sporadic colorectal cancer spreading and precursor evolution.

Adenomatous Polyposis Coli↗
PubMed2003

[Changes in the expression of cellular alpha and beta tubulins in patients with sporadic type colorectal cancer].

The aim of this preliminar report is to evaluate alfa and beta tubulins, components of cellular microtubules, alterated expression in sporadic colorectal cancer patients. The Authors considered 16 patients who underwent surgery for sporadic colorectal carcinoma with radical intent. Alfa and beta tubulins were evaluated in tumoral mucosa by immunohistochemistry. In 56.2% of the examined patients a low expression of alfa and beta tubulins was showed while the alteration of alfa tubulin was showed in 81.2% of the patients. This finding supports the hypothesis of Porter that alterations in microtubule structure might be part of the cellular response to DNA damage.

Colorectal Neoplasms↗
PubMed2003

[Telementoring in surgery].

Tele-mentoring is an interactive experimental method that allows young surgeons' education by distant learning tutoring of an expert surgeon. The problem about assessment of efficacy and quality of computer-assisted instruction is under evaluation today. Tele-mentoring is supported by videoconferencing system and it is not an exclusive methodology but an additional methodology to traditional didactic for clinicians and surgeons. It allows personal virtual trainings by computers and telecommunication systems. Videoconference allows tutoring for telemedicine, teletriage and telesurgery also.

Education, Distance↗
PubMed2002

Gastrointestinal involvement in paroxysmal nocturnal hemoglobinuria: first report of electron microscopic findings.

Thrombotic complications, particularly microthrombi involving intraabdominal veins leading to intestinal ischemia, have remained a major cause of morbidity in patients with paroxysmal nocturnal hemoglobinuria (PNH). While intestinal ischemia has been postulated to be the cause of recurrent bouts of abdominal pain in this population, direct antemortem evidence for this complication is scarcely documented in the literature. We describe a case of PNH in a patient who presented with abdominal distress three years after the initial diagnosis was established. Clinical features and a combination of diagnostic modalities, including radiography, endoscopy, and histology were used to make the prompt diagnosis of intestinal ischemia. This is the first case in which the electronic microscopy of the gastrointestinal lesion is described. Our patient was successfully treated with conservative measures and anticoagulation.

Abdominal Pain↗
PubMed2002

Pharmacokinetics and biochemical effects of hepapoietin in patients with chronic liver disease.

BACKGROUND: Hepapoietin is a naturally occurring cytokine that promotes hepatocyte growth. Animal studies have suggested that hepapoietin and hepatocyte growth factor have a potential role in the prevention and management of liver diseases. However, human studies have been lacking. AIM: To evaluate the safety and pharmacokinetics of single escalating doses of hepapoietin in patients with chronic liver disease. METHODS: An open-label, single escalating dose trial with five different doses of hepapoietin (1, 3, 10, 30 and 100 mg) was performed. Adults with chronic, compensated, non-viral liver disease were included. Liver function tests were obtained before dosing, 24 h after hepapoietin administration and on days 4, 7, 30 and 45. All patients were followed for 45 days. RESULTS: Twenty-five subjects received hepapoietin, with five subjects each at 1, 3, 10, 30 and 100 mg of hepapoietin. Significant decreases occurred in total bilirubin, ammonia, partial thromboplastin time and cholesterol levels overall, and both high-density and low-density lipoprotein cholesterol showed a downward trend. An increase in albumin was observed at the 30 mg dose level. Slight decreases in haemoglobin and red blood cell levels were observed at day 4, but returned to normal levels immediately thereafter. Child-Pugh scores from day 0 to day 7 were improved in 24%, stable in 64% and worse in 12% of patients. Hepatic encephalopathy displayed changes from day 0 to day 45 with improvement in 16%, no change in 80% and worsening in 4%. CONCLUSIONS: Hepapoietin in doses up to 100 mg is safe for use in humans. Potential benefits are suggested by significant decreases in bilirubin, ammonia, partial thromboplastin time and cholesterol levels and an increase in albumin. Further studies with multiple dosing regimens are needed to identify the clinical utility of hepapoietin in the management of chronic liver disease.

Area Under Curve↗
PubMed2002

Ileal T-pouch as a urinary continent cutaneous diversion: clinical and urodynamic evaluation.

OBJECTIVE: To report the functional results of continent cutaneous urinary diversion with ileum, using the serous-lined extramural valve and Mitrofanoff procedure for the continence mechanism. PATIENTS AND METHODS: From April 1999 to October 2001, 18 patients (mean age 68 years) underwent radical cystectomy for invasive bladder cancer involving the bladder neck, urethra or prostate; they then had an ileal continent cutaneous T pouch constructed. The mean (range) follow-up was 12 (4-20) months. The first five patients had reconstructions using the original orthotopic T-pouch configuration, but in subsequent patients the technique was simplified, reducing the ileal segments. The ureteric-intestinal anastomosis was made using a split-cuff nipple technique. RESULTS: All patients were continent day and night, and there were no late complications. All cutaneous continent T pouches had a good capacity and low pressure, with no urinary reflux. No catheterization difficulties were reported and the evacuation intervals were approximately 4 h. CONCLUSIONS: This ileal cutaneous continent diversion is a versatile technique; the T-valve can be used successfully as a continent mechanism, ensuring continence day and night. The simplified technique maintains a reservoir of good capacity and compliance, thus preserving approximately 13 cm of ileal tract. The ureteric intestinal anastomosis by the split-cuff nipple technique is suitable in undilated and peristaltic ureters.

Adult↗
PubMed2002

Beating-heart coronary artery bypass graft surgery at San Raffaele Hospital: four years of experience.

OBJECTIVE: To review the database of 1,902 consecutive patients who underwent coronary artery bypass graft (CABG) surgery in the period 1998 through 2001 at this institution, and to compare the preoperative status, anesthetic management, and postoperative outcome of 364 patients with the beating-heart technique with 1,538 patients who underwent the operation on cardiopulmonary bypass. DESIGN: Observational study. SETTING: University hospital. PARTICIPANTS: Consecutive patients (n = 1,902) who underwent CABG surgery in the period 1998 through 2001. MEASUREMENTS AND MAIN RESULTS: Comparison (chi-square test) of the preoperative status shows that surgeons' choice for the beating-heart technique was based on the presence of severe preoperative comorbidities: renal impairment (p < 0.0001), chronic obstructive pulmonary disease (p < 0.04), and low ejection fraction (p < 0.0001). On a multivariate analysis, the beating-heart technique was associated with reduced transfusion needs and duration of mechanical ventilation. CONCLUSION: Beating-heart surgery is gaining popularity as a safe method for myocardial revascularization. Excellent results have been achieved with this technique in this center.

Cardiopulmonary Bypass↗
PubMed2002

Histological and histochemical study of female germ cell development in the dusky grouper Epinephelus marginatus (Lowe, 1834).

The developmental stages of female germ cells were analysed in a wild population of the protogynous teleost Epinephelus marginatus (Lowe, 1834). 321 wild dusky grouper females were collected in the South Mediterranean Sea during the spawning season and their ovaries analysed using histological and histochemical techniques. Oocyte morphology, nucleus-cytoplasm ratio (N/C) range, location and movements of cytoplasmic inclusions during primary growth, vitellogenesis and final oocyte maturation were described. The distribution of proteins, lipids and carbohydrates through oocyte development was also investigated in 50 females. Lipid vesicles appeared firstly in the mid ooplasm of oocytes larger than 130 microm, at the beginning of the secondary growth phase. Immediately afterwards, small carbohydrate granules (PAS and Alcian blue positive) appeared before the occurrence of the first yolk granules. Tyrosine-enriched proteins were especially evidenced in the zona radiata interna of late vitellogenic oocytes. Specific lectin binding patterns reflected characteristic differences in the content and distribution of specific sugar moieties expressed in the oocytes during vitellogenesis and final maturation. At the end of vitellogenesis and during final maturation, follicular cells, zona radiata, and cortical alveoli were characterised by a strong increase of specific binding for WGA.

Animals↗
PubMed2002

[Reconstruction, application and evaluation of a finite element method to study the pelvic floor. Preliminary results].

BACKGROUND: To verify the possibility to apply the Finite Element Method of structural analysis (FEM) to the study of pelvis, with particular attention to the ligamental structures linking pubis to the cervix-urethra tract. METHODS: By means of FEMAP and Hypermesh pre-processors, the three-dimensional reconstruction of the anatomical model, has been mathematically made, using photographs of 80 cadaveric pelvis structure cross sections (3 mm one from the next). Then, with the NASTRAN code, the model has been solved. The deflection of the pelvis structures has been simulated and the more stressed anatomical zones have been located studying the distribution of stress in the numerical model. RESULTS: The analysis has pointed out that the most stressed areas of the pelvic floor are the cervix-urethra tract and the perineum trapezium below. The observation of the extent of the displacements, in the simulation of the deflection of the pelvis structures, has pointed out the importance of the role of the ligaments linking pubis to the cervix-urethra tract to distribute the resultant of loads on the pelvis structures in harmonic way. CONCLUSIONS: The results confirm the role of the ligamental structures between pubis and the cervix-urethra tract that, stressed as tie rods, subdivide the global load in the several components, with anterior-lateral direction, showing a non secondary role in the pelvis dynamics. The rational of the reconstruction of such structures in urological surgery is therefore strengthened, in order to restore the anatomical and functional support.

Finite Element Analysis↗