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Biomedical subjects

M Rossi

Publications and source records attributed to M Rossi.

At least 145 records · Page 8Linked to original sources
PubMed2001

[The general surgeon's experience in emergency gynaecological laparoscopy].

BACKGROUND: Early laparoscopy plays a very important role in the diagnosis and treatment of uncertain surgical diseases. Its use is not very clear, in part because it is a very new technique and secondly because its application in emergency surgery is very recent. The aim of this study is to evaluate the efficacy of this surgical approach. METHODS: In the last six years, during emergency laparoscopy, we diagnosed various gynaecological diseases. We performed 4 ovarian cystectomies (25%), 2 salpingectomies (12.5%), 6 salpingo-oophorectomies (37.5%), 2 myomectomies (18.75%), 1 endocoagulation (6.25%). RESULTS: Neither conversion in open surgery, nor major postoperatory complications were noted. Intervention time was shorter than that of the open technique. Return to normal activity was earlier. CONCLUSIONS: The results of this study contribute to demonstrate that, in emergency surgery, laparoscopy constitute a valid and efficient diagnostic and therapeutic technique. It is indicated for the treatment of acute abdomen of unknown origin.

Adult↗
PubMed2001

[Control of postoperative pain in heart surgery. Comparison of analgesics].

BACKGROUND: Evaluation of the efficacy of three analgesic drugs (tramadol, ketorolac, and morphine) for the control of postoperative pain in cardiac surgery. METHODS DESIGN: prospective randomized study. SETTING: University Hospital, Postoperative intensive care unit. PARTICIPANTS AND INTERVENTION: sixty patients, who underwent cardiac surgery, were studied. They were randomly allocated in four groups, treated with a different postoperative analgesic therapy: A) tramadol in continuous infusion; B) ketorolac in continuous infusion; C) tramadol, in repeated boluses; D) morphine, in repeated boluses. MEASUREMENTS: the analgesic efficacy of each drug and administration protocol was evaluated by hemodynamic stability, arterial blood gases analysis, Visual Analogue Scale (VAS), resting and after cough, the VAS derivatives PID and SPID, the concentration of plasma epinephrine and norepinephrine, at eight postoperative times. Adverse effects were also registered. RESULTS: Only tramadol, in continuous i.v. infusion, achieves the required analgesic effect, significantly decreasing both VAS scores, at the end of the administration of the drug. This treatment reduced epinephrine plasma levels in the first postoperative day, when the residual analgesic effect of surgical anesthesia can be considered disappeared. CONCLUSIONS: Tramadol in continuous infusion (dose 12 mg/h) proved to be effective for the control of postoperative pain after cardiac surgery. The proposed dose represents a good compromise between analgesic efficacy and interference with the vital functions of operated patients.

Adult↗
PubMed2001

[Post-partum vesicovaginal fistula: abdominal muscle strip treatment].

BACKGROUND: The Vesico-Vaginal Fistula (VVF) very often occur in tropical countries, but their treatment is usually not correct. METHODS: A surgical treatment was carried put on 68 patients affected by VVF from March 1986 to December 19997 in the Nazareth Hospital (Nairobi). Their mean age was 22 years old; 27 patients (39.7%) underwent surgery for the first time, while for 41 patients (60.2%) the treatment was repeated. Fourteen patients (20.5%) had also Vesico-Rectum-Vaginal Fistula (VRV). The VVF was cured with a transvaginal treatment using a Martius strip for 32 cases. For 16 cases both vaginal and abdominal treatment was performed in the same time using an abdominal muscle strip, which was inserted in the space between the vagina and bladder. In VRV and VVF combined cases, the VVF was treated in the following way: first of all, during the same session, the VVF was cured by making a colostomy and then, after 2 months VRV was treated. RESULTS: The follow-up took about 7.2 months; 62 patients (91.1%) recovered, for 6 cases treated only with transvaginal operation, it has been necessary a second surgical procedure owing to relapsing, and for 2 of them an abdominal muscle strip was used. CONCLUSIONS: In conclusion, while the transvaginal repair is satisfactory treatment for little fistula never surgically treated before, on the other hand the transabdominal vaginal treatment is the best cure forge large or relapsing fistulas.

Abdominal Muscles↗
PubMed2001

[Polyps (single or multiple) and juvenile polyposis].

The authors underline the important aspects of juvenile familial polyposis (JFP), a disease transmitted as an autosomal dominant trait. A case of JFP characterized by the presence of hundreds of polyps in the colo-rectal intestinal tract, is analyzed. The single juvenile polyp, multiple polyps (=/>5 polyps) and the sporadic form are examined. These are mucous hamartomas which can undergo neoplastic transformation (in carcinoma in 68% of untreated cases), a behaviour similar to that of adenomatous polyps. They differ from the later due to the following features: epidemiology (earlier appearance age), anatomopathology (stroma), clinical observation (self-recovery in some cases) and genetics (10q23.3-18q21, genetic mutations in a locus different those of adenomatous polyps). It is also necessary to determine its extension by means of colonoscopy, ileoscopy, gastroscopy and small bowel barium enema. Patients' screening through construction of the genealogical family tree is fundamental. Isolation of possible degenerative aspects of the polyps through biopsy is also fundamental. Single or multiple polyps are treated endoscopically, the juvenile polyposis is treated surgically (colectomy, total colectomy). A rigorous follow-up of the patients and their family members is recommended.

Adenomatous Polyposis Coli↗
PubMed2001

Laparoscopic versus open cholecystectomy. An analysis of clinical and financial aspects.

BACKGROUND: The aim of this study is to assess the clinical and financial aspects of laparoscopic cholecystectomy (LC) compared to open cholecystectomy (OC). METHODS: Thirty-six patients treated with LC were prospectively, not randomized, compared with 35 patients that underwent OC. The data used were taken from local registers, patient-statistics and hospital accounting systems. We evaluated the costs, morbidity and mortality for both surgical procedures. RESULTS: Significant differences were observed concerning the number of days that pain was suffered (mean 7.6 days in LC versus 18.5 days in OC), the duration of postoperative hospitalization (LC mean 2-3 days; OC 7-9 days), the extent of postoperative monitoring performed, and the number of days in order to return to normal activity (mean 4.4 days in LC; mean 7.6 days in OC). Calculation of the costs was based on the Diagnosis Related Groups (DRG). The profit for a DRG is the result of the difference between the reimbursement obtained from the execution of the operation and the cost in order to carry it out. The total cost for the execution of LC is Italian 3,332,632 pound sterling with a profit of Italian 1,208,807 pound sterling while for OC the cost is 4,007,359 pound sterling and the profit is 347,041 pound sterling. CONCLUSIONS: The results of our study is that, clinically and financially, LC has obvious advantages over OC.

Adult↗
PubMed2001

Effects of a 100 metacercarial cyst inoculum on the host-parasite relationship of Echinostoma caproni and ICR mice.

The host-parasite relationship of a 100 metacercarial cyst inoculum of Echinostoma caproni in the ICR mouse was examined. Three groups of mice, A, B and C, each with six mice per group were used and all mice were necropsied at 14 days postinfection (p.i.), at which time the worms were ovigerous. Group A consisted of uninfected controls, whereas group B received 25 cysts per mouse (low dose) and group C received 100 cysts per mouse (high dose). There was no significant difference in food consumption between any of the groups from 0 to 14 days p.i. Control mice increased their body weight by 12%, group B by 5%, and group C showed a less than 1% increase in body weight between 0 and 14 days p.i. Echinostome parasitism caused a significant increase in the diameter of the mouse gut, with the gut of group C being more significantly dilated than that of either group A or B. The average worm recovery from group B was 20 worms per host, compared to 72 worms per host from group C. The mean wet and dry weights per worm from group B were 2.4 and 0.4 mg, respectively as compared to 0.6 and 0.2 mg respectively for group C. The mean number of uterine eggs per worm from group B was 180 compared to 125 for worms from group C. Worms from group C were more widely distributed in the small intestine than those from group B. Crowding effects associated with the high dose infection were clearly demonstrated in E. caproni from ICR mice.

Animals↗
PubMed2000

Programmed cell death (PCD) associated with the stilbene motif of arotinoids: discovery of novel apoptosis inducer agents possessing activity on multidrug resistant tumor cells.

Considering that the stereochemistry of the C9-C10 alkenyl portion of natural 9-cis-RA, as the one of the olefinic moiety of the previously described isoxazole retinoid 4, seems of particular importance for their apoptotic activity, we prepared a novel class of TTNPB analogues bearing both the cis or trans configuration of the alkenyl portion. The compounds were evaluated in vitro for their cytotoxic and apoptotic activities. We discovered that the cis-TTNPB 9c possesses apoptotic activity comparable with that of the retinoid 4. Moreover, the amino arotinoid 16c showed potent apoptotic activity in HL60 promyelocytic leukemia cells. Interestingly, 16c proved to be a particularly potent apoptosis-inducing agent active in multidrug resistant (MDR) cell lines. Therefore, to the best of our knowledge, 16c may represent the first known aminoarotinoid endowed with potent apoptotic activity in MDR cells. Taken together, these results seem to point out that the cis-stilbene motif of arotinoids may be at least an important feature in conferring cytotoxic and apoptotic activity to this class of compounds.

Antineoplastic Agents↗
PubMed2000

Lysyl hydroxylase 3 is a multifunctional protein possessing collagen glucosyltransferase activity.

Lysyl hydroxylase (EC ) and glucosyltransferase (EC ) are enzymes involved in post-translational modifications during collagen biosynthesis. We reveal in this paper that the protein produced by the cDNA for human lysyl hydroxylase isoform 3 (LH3) has both lysyl hydroxylase and glucosyltransferase (GGT) activities. The other known lysyl hydroxylase isoforms, LH1, LH2a, and LH2b, have no GGT activity. Furthermore, antibodies recognizing the amino acid sequence of human LH3 and those against a highly purified chicken GGT partially inhibited the GGT activity. Similarly, a partial inhibition was observed when these antibodies were tested against GGT extracted from human skin fibroblasts. In vitro mutagenesis experiments demonstrate that the amino acids involved in the GGT active site differ from those required for LH3 activity.

Alternative Splicing↗
PubMed2000

A snapshot of a transition state analogue of a novel thermophilic esterase belonging to the subfamily of mammalian hormone-sensitive lipase.

EST2 is a novel thermophilic carboxylesterase, isolated and cloned from Alicyclobacillus (formerly Bacillus) acidocaldarius, which optimally hydrolyses esters with acyl chain lengths of six to eight carbon atoms at 70 degrees C. On the basis of the amino acid sequence homology, it has been classified as a member of the mammalian hormone-sensitive lipase (HSL) subfamily. The crystal structure of EST2, complexed with a sulphonyl derivative, has been determined at 2.6 A resolution by a multiple wavelength anomalous diffraction experiment on a seleno-methionine derivative. EST2 presents a canonical alpha/beta hydrolase core, shielded at the C-terminal side by a cap region built up of five helices. It contains the lipase-like catalytic triad, Ser155, His282 and Asp252, whereby the nucleophile is covalently modified. This allows an unambiguous view of the putative active site of EST2, detecting the oxyanion hole, in whose formation the amino acid sequence motif His81-Gly82-Gly83-Gly84 is involved, and the hydrophobic binding pocket for the acyl chain. The structural model here reported provides the first example of a transition state analogue of an esterase/lipase belonging to the HSL group, thus affording useful information for the design of medical inhibitors. Moreover, as the first X-ray structure of a thermophilic carboxylesterase, the comparison with its mesophilic homologue, the Brefeldin A esterase (BFAE) from Bacillus subtilis, allows the identification of putative determinants of thermal stability.

Amino Acid Sequence↗
PubMed2000

PCR performance of the B-type DNA polymerase from the thermophilic euryarchaeon Thermococcus aggregans improved by mutations in the Y-GG/A motif.

The effect of mutations in the highly conserved Y-GG/A motif of B-type DNA polymerases was studied in the DNA polymerase from the hyperthermophilic euryarchaeon Thermococcus aggregans. This motif plays a critical role in the balance between the synthesis and degradation of the DNA chain. Five different mutations of the tyrosine at position 387 (Tyr387-->Phe, Tyr387-->Trp, Tyr387-->His, Tyr387-->Asn and Tyr387-->Ser) revealed that an aromatic ring system is crucial for the synthetic activity of the enzyme. Amino acids at this position lacking the ring system (Ser and Asn) led to a significant decrease in polymerase activity and to enhanced exonuclease activity, which resulted in improved enzyme fidelity. Exchange of tyrosine to phenylalanine, tryptophan or histidine led to phenotypes with wild-type-like fidelity but enhanced PCR performance that could be related to a higher velocity of polymerisation. With the help of a modelled structure of T.aggregans DNA polymerase, the biochemical data were interpreted proposing that the conformation of the flexible loop containing the Y-GG/A motif is an important factor for the equilibrium between DNA polymerisation and exonucleolysis.

Amino Acid Motifs↗
PubMed2000

The chromosomal protein sso7d of the crenarchaeon Sulfolobus solfataricus rescues aggregated proteins in an ATP hydrolysis-dependent manner.

In this work, we show that the nonspecific DNA-binding protein Sso7d from the crenarchaeon Sulfolobus solfataricus displays a cation-dependent ATPase activity with a pH optimum around neutrality and a temperature optimum of 70 degrees C. Measurements of tryptophan fluorescence and experiments that used 1-anilinonaphthalene-8-sulfonic acid as probe demonstrated that ATP hydrolysis induces a conformational change in the molecule and that the binding of the nucleotide triggers the ATP hydrolysis-induced conformation of the protein to return to the native conformation. We found that Sso7d rescues previously aggregated proteins in an ATP hydrolysis-dependent manner; the native conformation of Sso7d forms a complex with the aggregates, while the ATP hydrolysis-induced conformation is incapable of this interaction. Sso7d is believed to be the first protein isolated from an archaeon capable of rescuing aggregates.

Adenosine Triphosphatases↗
PubMed2000

Synthesis, structure, and antitumor activity of a novel tetranuclear titanium complex.

The coordination complex cyclo-tetrakis[bis(1-phenyl-3-methyl-4-benzoylpyrazolon-5-ato++ +)mu-o xotitanium(IV)] has been synthesized and characterized with IR and NMR spectroscopies and X-ray diffraction. The core of this species consists of an eight-membered Ti-mu-oxo ring with alternate short-long Ti-O bond lengths. Besides these two O ligands, each metal is bound octahedrally to four O atoms from two chelating 1-phenyl-3-methyl-4-benzoylpyrazolon-5-ato anions. Several sets of Ti-O bond lengths are present: the shortest are the two Ti-O(oxo) (which are cis to each other), the longest are the two Ti-O(acyl) (cis to each other), and the two Ti-O(pyrazolonato) (trans to each other) are intermediate. The beta-diketonate ligand asymmetry, a feature considered essential in other antitumor Ti compounds, induces the short-long Ti-O(oxo) sequence of bond lengths. The antitumor activity of this compound, encapsulated in a dipalmitoylphosphatidylcholine liposome, has been studied in vitro using TA-3 (mouse mammary adenocarcinoma), HEP-2 (human epithelial larynx carcinoma), and VERO (African green monkey kidney) cell lines and in vivo in CF-1 and AJ female mice ip inoculated with TA-3. In vitro cytotoxicity is greater for TA-3 than for HEP-2 and null for VERO cell lines. In vivo results show a marked increase in survival time (T/C = 293% for AJ and 208% for CF-1), whereas tumor weight decrease was observed for CF-1-treated mice. These results suggest the Ti complex-liposome system may be promising as an antitumor drug.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

Physical and functional interaction between p53 mutants and different isoforms of p73.

p53 is the most frequently inactivated tumor suppressor gene in human cancer, whereas its homologue, p73, is rarely mutated. Similarly to p53, p73 can promote growth arrest or apoptosis when overexpressed in certain p53-null tumor cells. It has previously been shown that some human tumor-derived p53 mutants can exert gain of function activity. The molecular mechanism underlying this activity remains to be elucidated. We show here that human tumor-derived p53 mutants (p53His175 and p53Gly281) associate in vitro and in vivo with p73 alpha, beta, gamma, and delta. This association occurs under physiological conditions, as verified in T47D and SKBR3 breast cancer cell lines. The core domain of mutant p53 is sufficient for the association with p73, whereas both the specific DNA binding and the oligomerization domains of p73 are required for the association with mutant p53. Furthermore, p53His175 and p53Gly281 mutants markedly reduce the transcriptional activity of the various isoforms of p73. Thus, human tumor-derived p53 mutants can associate with p73 not only physically but also functionally. These findings define a network involving mutant p53 and the various spliced isoforms of p73 that may confer upon tumor cells a selective survival advantage.

Breast Neoplasms↗
PubMed2000

Visual feedback has differential effects on reaching movements in Parkinson's and Alzheimer's disease.

We examine the role of visual feedback in the programming and execution of reaching movement in patients with Parkinson's disease without cognitive impairment and patients with Alzheimer's disease without extrapyramidal signs. Controls were normally aging subjects. All subjects moved a cursor to targets on a digitizing tablet without seeing their limb. Starting and target positions were always visible on a screen while, during movement, cursor position was either visible or blanked. They were instructed to make uncorrected movements, as fast and as accurate as possible without minimizing reaction time. In absence of visual feedback, movement accuracy in patients with AD was severely impaired. Hand paths of parkinsonian patients were as accurate as normal subjects' with similar temporal velocity profiles and movement speed. With cursor feedback, accuracy was the same in the three groups, although movement speed and transport phase in patients with Alzheimer's disease were significantly reduced compared to the other groups. Also, movements of parkinsonian patients showed shorter transport phase and lower mean velocity than controls'. The different characteristics of the motor performance suggests that in the two diseases visual information is used differently for both motor programming and execution: patients with Alzheimer's disease, while scarcely using feed forward commands, relied on continuous on-line external cues. The correlation of motor performance with cognitive impairment argues against the hypothesis of basal ganglia involvement in AD. The motor abnormalities we found may represent early subclinical manifestation of apraxic disturbance. Parkinsonian patients showed higher reliance on feedback commands only with cursor feedback: this could be explained by their difficulty in engaging effectively automatic routines when distractors are present.

Aged↗
PubMed2000

Oxygen: friend or foe? Archaeal superoxide dismutases in the protection of intra- and extracellular oxidative stress.

Both "environmental chemistry" and metabolic biochemical reactions can constantly generate in vivo free radicals and other oxygen-derived species that can cause severe damage to almost all biomolecules, especially to DNA, proteins, and lipids. The superoxide anion has been shown to be the most readily generated and spread radical among organisms and it is a common intermediate of oxidative stress processes in the cells. The antioxidant defense system of superoxide dismutases (SOD) scavenges and minimizes the formation of this radical, and thus plays a major role in reducing cumulative oxidative damage in different cell compartments both in aerobic and anaerobic cells. In the cell, cytosol SODs are constitutively present and induced by many oxidative agents able to raise the superoxide concentrations. Presence of SODs, however, in extracellular cell-associated locations demonstrates how valuable they are in maintaining the integrity of cells against oxidative stress generated by the cell environment, particularly upon increased oxygenation. Because SODs have recently been found in Archaea, which are prokaryotes, sometimes living in extreme environments, even in anaerobic ones, these enzymes can be considered essential: they may have allowed the evolution of aerobic respiration starting from an ancient form of oxygen-insensitive life.

Archaea↗
PubMed2000

Universality class of absorbing phase transitions with a conserved field

We investigate the critical behavior of systems exhibiting a continuous absorbing phase transition in the presence of a conserved field coupled to the order parameter. The results obtained point out the existence of a new universality class of nonequilibrium phase transitions that characterizes a vast set of systems including conserved threshold transfer processes and stochastic sandpile models.

Journal Article↗