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M Zago

Publications and source records attributed to M Zago.

At least 19 recordsLinked to original sources
PubMed2006

Diaphragmatic acute massive herniation after laparoscopic gastroplasty for esophagectomy.

Minimally invasive techniques are increasingly being used for oesophagectomy. Diaphragmatic hernia is a rare complication of gastroplasty in open surgery. One of the advantages of the laparoscopic technique, the lack of peritoneal adhesions, may lead to an increased rate of this complication. We report two cases of diaphragmatic acute massive herniation after laparoscopic gastroplasty for esophagectomy out of a series of 44 laparoscopic gastroplasties performed over 33 months. We discuss some technical aspects related to its occurrence. Prevention should include a limited crural division and fixation of the gastric tube to the diaphragmatic crura at primary surgery.

Adenocarcinoma↗
PubMed2004

Pre-operative endoscopic ultrasonography can optimise the management of patients undergoing laparoscopic cholecystectomy with abnormal liver function tests as the sole risk factor for choledocholithiasis: a prospective study.

BACKGROUND: Pre-operative endosonography has been proposed as a cost-effective procedure in the management of patients who undergo laparoscopic cholecystectomy having an intermediate risk of common bile duct stones. We prospectively evaluated the impact of pre-operative endosonography on the management of patients facing laparoscopic cholecystectomy with abnormal liver function tests as the sole risk factor for choledocolithiasis. METHODS: Among 587 consecutive patients scheduled for laparoscopic cholecystectomy, 47 (8%) patients having one or more abnormal liver function tests but a normal appearance of common bile duct at abdominal ultrasound, underwent pre-operative endosonography. In patients with endosonography-detected common bile duct stones, a pre-operative endoscopic retrograde cholangiography was performed, or an intra-operative endoscopic retrograde cholangiography was scheduled. In all endosonography-negative patients, an intra-operative trans-cystic cholangiography was performed. RESULTS: Endosonography detected common bile duct stones in nine patients (19%) but only in five of them stones were radiologically confirmed (PPV 0.55). Endosonography-detected stones were confirmed in four of four (100%) patients in whom cholangiography was performed within 1 week, but only in one of five (20%) patients in whom radiology was further delayed (P < 0.05). In three of four cases (75%), stones detected at endosonography but not confirmed at X-rays, were smaller than 2.0 mm. Among 38 patients with negative endosonography, common bile duct stones were found in two patients (NPV 0.95), whereas unplanned endoscopic stone extraction was needed only in one patient (NPV 0.97). CONCLUSIONS: Pre-operative endosonography can spare unnecessary pre-operative endoscopic retrograde cholangiography as well as inappropriate scheduling of intra-operative endoscopic retrograde cholangiography in patients undergoing laparoscopic cholecystectomy with abnormal liver function tests. To maximise the impact of endosonography on the management of these patients, the procedure should be performed immediately before laparoscopic cholecystectomy.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed2004

Evaluation of bacterial communities belonging to natural whey starters for Grana Padano cheese by length heterogeneity-PCR.

AIMS: To detect bacteria present in controlled dairy ecosystems with defined composition by length-heterogeneity (LH)-PCR. LH-PCR allows to distinguish different organisms on the basis of natural variations in the length of 16S rRNA gene sequences. METHODS AND RESULTS: LH-PCR was applied to depict population structure of the lactic acid bacteria (LAB) species recoverable from Grana Padano cheese whey starters. Typical bacterial species present in the LAB community were evidenced and well discriminated. Small differences in species composition, e.g. the frequent finding of Streptococcus thermophilus and the constant presence of thermophilic lactobacilli (Lactobacillus helveticus, Lact. delbrueckii subsp. lactis/bulgaricus and Lact. fermentum) were reliably highlighted. Specificity of LH-PCR was confirmed by species-specific PCR from total DNA of the cultures. CONCLUSIONS: LH-PCR is a useful tool to monitor microbial composition and population dynamics in dairy starter cultures. When present, non-dominant bacterial species present in the whey starters, such as Strep. thermophilus, can easily be visualized and characterized without isolating and cultivating single strains. A similar approach can be applied to more complex dairy ecosystems such as milk or cheese curd. SIGNIFICANCE AND IMPACT OF THE STUDY: Community members and differences in population structure of controlled dairy ecosystems such as whey starters for hard cheeses can be evaluated and compared in a relative easy, fast, reliable and highly reproducible way.

Cheese↗
PubMed2002

Kinematic control of walking.

The planar law of inter-segmental co-ordination we described may emerge from the coupling of neural oscillators between each other and with limb mechanical oscillators. Muscle contraction intervenes at variable times to re-excite the intrinsic oscillations of the system when energy is lost. The hypothesis that a law of coordinative control results from a minimal active tuning of the passive inertial and viscoelastic coupling among limb segments is congruent with the idea that movement has evolved according to minimum energy criteria (1, 8). It is known that multi-segment motion of mammals locomotion is controlled by a network of coupled oscillators (CPGs, see 18, 33, 37). Flexible combination of unit oscillators gives rise to different forms of locomotion. Inter-oscillator coupling can be modified by changing the synaptic strength (or polarity) of the relative spinal connections. As a result, unit oscillators can be coupled in phase, out of phase, or with a variable phase, giving rise to different behaviors, such as speed increments or reversal of gait direction (from forward to backward). Supra-spinal centers may drive or modulate functional sets of coordinating interneurons to generate different walking modes (or gaits). Although it is often assumed that CPGs control patterns of muscle activity, an equally plausible hypothesis is that they control patterns of limb segment motion instead (22). According to this kinematic view, each unit oscillator would directly control a limb segment, alternately generating forward and backward oscillations of the segment. Inter-segmental coordination would be achieved by coupling unit oscillators with a variable phase. Inter-segmental kinematic phase plays the role of global control variable previously postulated for the network of central oscillators. In fact, inter-segmental phase shifts systematically with increasing speed both in man (4) and cat (38). Because this phase-shift is correlated with the net mechanical power output over a gait cycle (3, 4), phase control could be used for limiting the overall energy expenditure with increasing speed (22). Adaptation to different walking conditions, such as changes in body posture, body weight unloading and backward walk, also involves inter-segmental phase tuning, as does the maturation of limb kinematics in toddlers.

Animals↗
PubMed2001

Mutations of the phenylalanine hydroxylase (PAH) gene in Brazilian patients with phenylketonuria.

In the present study, 115 Brazilian families with phenylketonuria (PKU), mainly from the Southeast of the country, were studied using three laboratory methods (DGGE, SSCP, and sequencing). All 13 exons of the PAH gene were analyzed, including the splicing sites and the promoter region. We identified 50 distinct mutations and characterized 91% of the mutant alleles. The five most prevalent mutations of the 50 mutations identified (50% of the PKU alleles) were IVS10nt-11G-->A (17.4%), followed by R261Q (12.2%), V388M (9.1%), R252W (6.5%), and R270K (4.8%). The other mutations were rare. The mutation spectrum included 10 novel mutations (IVS5nt-54A-->G, IVS6nt17G-->T, E205A, F240S, K274E, I318T, L321L, C357G, IVS11nt17G-->A, and S411X). To characterize the origin and distribution of the PAH alleles we determined the association between the detected mutations and the PCR/RFLP haplotypes and VNTR alleles located on the PAH gene. For those patients whose mutant alleles were detected, we calculated the correlation with pretreatment phenylalanine levels, thus establishing a genotype/phenotype correlation. The present results confirm the marked heterogeneity observed at the PAH locus and contribute to the understanding of the distribution and frequency of PKU mutations in the Brazilian population.

Brazil↗
PubMed2001

Laparoscopic treatment of epiphrenic diverticula.

BACKGROUND AND PURPOSE: Epiphrenic diverticula are a rare disease probably caused by long-standing impairment of esophageal motor activity. Symptomatic disease, which may worsen clinically during follow-up even to severe symptoms, is usually considered an indication for surgical treatment. Surgery for epiphrenic diverticula consists of diverticulectomy, which traditionally is performed through a left thoracotomy; a myotomy and partial fundoplication are generally included in order to treat the underlying motor disorder and to prevent or correct reflux. The same principles of surgical treatment can be achieved through the laparoscopic transhiatal approach. The aim of this paper is to describe the technique and the results of laparoscopic diverticulectomy combined with esophageal myotomy and antireflux wrap to treat epiphrenic diverticula of the esophagus. PATIENTS AND METHODS: From January 1994 through May 2001, 11 patients underwent laparoscopic transhiatal diverticulectomy, esophageal myotomy, and partial fundoplication at our institution. RESULTS: In all patients, the operation was completed through the minimally invasive access. The postoperative course was complicated in one patient (9%), who had a leak from the staple line, which was repaired through a thoracotomy. At follow-up, this patient had persistence of a small pouch at the diverticuletomy site. However, he was asymptomatic. All other patients were free of symptoms and without recurrence. CONCLUSION: Laparoscopy offers good access to the distal esophagus and the inferior mediastinum. Removal of the diverticulum, treatment of the motor disorder, and prevention of postoperative reflux can all be obtained through this approach. The immediate postoperative and long-term results are satisfactory.

Aged↗
PubMed2000

Interactions between posture and locomotion: motor patterns in humans walking with bent posture versus erect posture.

Human erect locomotion is unique among living primates. Evolution selected specific biomechanical features that make human locomotion mechanically efficient. These features are matched by the motor patterns generated in the CNS. What happens when humans walk with bent postures? Are normal motor patterns of erect locomotion maintained or completely reorganized? Five healthy volunteers walked straight and forward at different speeds in three different postures (regular, knee-flexed, and knee- and trunk-flexed) while their motion, ground reaction forces, and electromyographic (EMG) activity were recorded. The three postures imply large differences in the position of the center of body mass relative to the body segments. The elevation angles of the trunk, pelvis, and lower limb segments relative to the vertical in the sagittal plane, the ground reaction forces and the rectified EMGs were analyzed over the gait cycle. The waveforms of the elevation angles along the gait cycle remained essentially unchanged irrespective of the adopted postures. The first two harmonics of these kinematic waveforms explain >95% of their variance. The phase shift but not the amplitude ratio between the first harmonic of the elevation angle waveforms of adjacent pairs was affected systematically by changes in posture. Thigh, shank, and foot angles covaried close to a plane in all conditions, but the plane orientation was systematically different in bent versus erect locomotion. This was explained by the changes in the temporal coupling among the three segments. For walking speeds >1 m s(-1), the plane orientation of bent locomotion indicates a much lower mechanical efficiency relative to erect locomotion. Ground reaction forces differed prominently in bent versus erect posture displaying characteristics intermediate between those typical of walking and those of running. Mean EMG activity was greater in bent postures for all recorded muscles independent of the functional role. The waveforms of the muscle activities and muscle synergies also were affected by the adopted posture. We conclude that maintaining bent postures does not interfere either with the generation of segmental kinematic waveforms or with the planar constraint of intersegmental covariation. These characteristics are maintained at the expense of adjustments in kinetic parameters, muscle synergies and the temporal coupling among the oscillating body segments. We argue that an integrated control of gait and posture is made possible because these two motor functions share some common principles of spatial organization.

Adult↗
PubMed1999

Basal ganglia and gait control: apomorphine administration and internal pallidum stimulation in Parkinson's disease.

Gait coordination was analyzed (four-camera 100 Hz ELITE system) in two groups of idiopathic Parkinson disease (PD) patients. Five patients underwent continuous infusion of apomorphine and were recorded in two different sessions (APO OFF and APO ON) in the same day. Three patients with a previous chronic electrode implantation in both internal globi pallidi (GPi) were recorded in the same experimental session with the electrodes on and off (STIM ON and STIM OFF). The orientation of both the trunk and the lower-limb segments was described with respect to the vertical in the sagittal plane. Lower-limb inter-segmental coordination was evaluated by analyzing the co-variation between thigh, shank, and foot elevation angles by means of orthogonal planar regression. At least 30 gait cycles per experimental condition were processed. We found that the trunk was bent forward in STIM OFF, whereas it was better aligned with the vertical in STIM ON in both PD groups. The legs never fully extended during the gait cycle in STIM OFF, whereas they extended before heel strike in STIM ON. The multisegmental coordination of the lower limb changed almost in parallel with the changes in trunk orientation. In STIM OFF, both the shape and the spatial orientation of the planar gait loops (thigh angle vs. shank angle vs. foot angle) differed from those of physiological locomotion, whereas in STIM ON the gait loop tended to resume features closer to the control. Switching the electrodes on and off in patients with GPi electrodes resulted in quasi-parallel changes of the trunk inclination and of the planar gait loop. The bulk of the data suggest that the basal-ganglia circuitry may be relevant in locomotion by providing an appropriate spatio-temporal framework for the control of posture and movement in a gravity-based body-centered frame of reference. Pallido-thalamic and/or pallido-mesencephalic pathways may influence the timing of the inter-segmental coordination for gait.

Aged↗
PubMed1999

Viewer-centered and body-centered frames of reference in direct visuomotor transformations.

It has been hypothesized that the end-point position of reaching may be specified in an egocentric frame of reference. In most previous studies, however, reaching was toward a memorized target, rather than an actual target. Thus, the role played by sensorimotor transformation could not be disassociated from the role played by storage in short-term memory. In the present study the direct process of sensorimotor transformation was investigated in reaching toward continuously visible targets that need not be stored in memory. A virtual reality system was used to present visual targets in different three-dimensional (3D) locations in two different tasks, one with visual feedback of the hand and arm position (Seen Hand) and the other without such feedback (Unseen Hand). In the Seen Hand task, the axes of maximum variability and of maximum contraction converge toward the mid-point between the eyes. In the Unseen Hand task only the maximum contraction correlates with the sight-line and the axes of maximum variability are not viewer-centered but rotate anti-clockwise around the body and the effector arm during the move from the right to the left workspace. The bulk of findings from these and previous experiments support the hypothesis of a two-stage process, with a gradual transformation from viewer-centered to body-centered and arm-centered coordinates. Retinal, extra-retinal and arm-related signals appear to be progressively combined in superior and inferior parietal areas, giving rise to egocentric representations of the end-point position of reaching.

Adult↗
PubMed1998

The frequency of 844ins68 mutation in the cystathionine beta-synthase gene is not increased in patients with venous thrombosis.

BACKGROUND AND OBJECTIVES: A frequent mutation in the cystathionine beta-synthase (CBS) gene (844ins68, a 68-bp insertion in the coding region of exon 8) was recently discovered. In the present study we investigated this mutation as a candidate risk factor for venous thrombosis. DESIGN AND METHODS: The prevalence of the 844ins68 CBS mutation was determined in 101 patients with objectively diagnosed deep venous thrombosis and in 101 healthy controls matched for age, sex and race. PCR amplification of a DNA fragment containing exon 8 of the CBS gene was employed to determine the genotypes. Additionally, Bsrl restriction enzyme digestion of the PCR products was performed in all samples from carriers of the insertion, to test for concurrent presence of a second mutation (T833C) in the CBS gene. RESULTS: The insertion was found in 21 out of 101 patients (20.8%; allele frequency 0.109) and in 20 out of 101 controls (19.8%; allele frequency 0.114), yielding a relative risk for venous thrombosis related to the 844ins68 CBS mutation close to 1.0. In addition, the T833C CBS mutation was detected in all alleles carrying the 844ins68 CBS insertion, confirming the co-inheritance of the two mutations. INTERPRETATION AND CONCLUSIONS: Our findings do not support the hypothesis that the 844ins68 mutation in the CBS gene is a genetic risk factor for venous thrombosis.

Adolescent↗
PubMed1997

Identification of a North American mosquito species, Aedes atropalpus (Diptera: Culicidae), in Italy.

In late September 1996, during a routine survey for Aedes albopictus in Italy, a population of Aedes atropalpus s.s. was discovered in the Veneto Region (northern Italy). Larvae were collected in 2 tire storage areas belonging to tire recapping companies that imported loads of car and large equipment used tires from eastern Europe and North America. Aedes atropalpus is found only in North America and hence it is the origin of this species. Control measures were carried out in October, but by then any remaining Ae. atropalpus would have been diapausing in the egg stage. A follow-up survey will be conducted in the spring of 1997 to assess if Ae. atropalpus has been established in the area and the extent of the spread in Italy.

Aedes↗
PubMed1995

Efficacy of octreotide in the prevention of pancreatic fistula after elective pancreatic resections: a prospective, controlled, randomized clinical trial.

BACKGROUND: A prospective, randomized controlled clinical trial was conducted in 33 Italian surgical departments with the aim of evaluating the efficacy of octreotide in the prevention of pancreatic fistula after elective pancreatic resections. METHODS: Between July 1990 and May 1992, 278 patients were enrolled in the study. Fifty-four dropped out because of unresectable disease and six were excluded because of protocol violation; the remaining 218 were randomly assigned to the octreotide group (n = 111) or to the placebo group (n = 107). There were 131 men and 87 women with a mean age of 58.2 +/- 11.7 yrs. Pancreaticoduodenectomy was the most common operation performed (n = 143), sixty-four percent of patients had a pancreatic or periampullary cancer; chronic pancreatitis accounted for 8.2% of cases. RESULTS: Mortality rate was 6.9%. A pancreatic fistula occurred in 31 patients (14.2%), 9% in the octreotide group and 19.6% in the placebo group (p < 0.05). Morbidity rate was significantly lower in the octreotide (21.6%) than in the placebo group (36.4%) (p < 0.05). When specific pancreatic complications were grouped together and evaluated, they occurred less frequently in the treated (15.3%) than in the placebo group (29.9%) (p < 0.05). CONCLUSIONS: Octreotide was able to reduce significantly the incidence of pancreatic fistula after elective pancreatic resections.

Aged↗
PubMed1992

[Cognitive changes in workers at a data processing company].

A study of 191 data processing workers undertaken in Porto Alegre, Brazil, in 1989, is presented. The relationship between complaints of loss of memory and their respective scores on cognitive testing in three groups of workers, one with automatized repetitive activities and two others with diversified activities, is analysed. The scores and complaints are compared with the results of a screening test for psychiatric disorders in order to verify the influence of this confounding factor. No significant evidence of cognitive problems was found despite the high prevalence of complaints of memory loss in this population (65.4%). There is a significant statistical association between these complaints and the scores of the psychiatric testing. It is suggested that futures studies should emphasize psychiatric analysis with a view to clarifying the complaints of Data Processing workers.

Adult↗
PubMed1991

[Aneurysms in various segments of the hepatic artery. Treatment by resection].

The authors report two cases of aneurysms of the hepatic artery, one of which, with a intrahepatic localisation, was complicated by rupture and infection. The etiology was atherosclerotic in the case involving the main trunk of the hepatic artery, and polyarteritis nodosa in the case with intrahepatic involvement. Both were resected; the extrahepatic aneurysm was excised and a venous graft inserted, whereas in the one with intrahepatic involvement, right lobectomy was performed. On the basis of these cases, the authors discuss the various etiologies and the problems related to the indications and surgical techniques for aneurysms of the main trunk of the hepatic artery and those of its intrahepatic branches.

Aged↗
PubMed1990

HIV 1 and HIV 2 prevalence of seropositivity in a population of West Africa.

In the month of August 1986, tests for anti-HIV 1 and anti-HIV 2 antibodies were performed in people coming to the hospital of Tanguietà (North Benin) (401 subjects) and in people working in the same hospital (23 subjects). The study revealed an anti-HIV 1 antibody prevalence of 0.4% (2/424) and an anti-HIV 2 prevalence of 0.2% (1/419). Seropositivity for both antibodies (anti-HIV 1 and anti-HIV 2) was found in one case; the other case was positive only for anti-HIV 1. The changing composition of the population due to frequent migratory displacements lead us to expect some possible alterations of the registered data in the future.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Segmental splenectomy. Usefulness of linear surgical staplers].

As the high risk of sepsis after splenectomy is well recognized, reliable conservative surgical techniques in splenic surgery are widely advocated. Among these, segmental splenectomy carries specific and increasing indications. The use of linear staplers makes this operation quicker and safer. On the basis of a personal observation, Authors examine the anatomical features on which this operation is based, the surgical technique and the technical details to be followed using these devices. The advantages offered by staplers in this surgery allow to widen the indications to partial splenectomy, so as to yield a true primary prophylaxis of the post-splenectomy sepsis.

Adolescent↗