Biomedical subjects

M Guerra

Publications and source records attributed to M Guerra.

At least 55 records · Page 3Linked to original sources

PubMed1997

Results of electroencephalographic monitoring during 369 consecutive carotid artery revascularizations.

A continuous intraoperative EEG monitoring was performed in 369 consecutive carotid artery revascularizations (CARs) (321 patients) to minimize the intraoperative neurological morbidity. There were 227 carotid endarterectomies and patch graft angioplasty (198 patients), 79 carotid eversion endarterectomies (70 patients) and 58 internal carotid artery reimplantations into the common carotid artery (48 patients). Indications for CARs were TIAs (141, 43.9%), amaurosis fugax (60, 18.6%) and fixed or partial nonprogressing stroke (14, 4.3%). One hundred and six patients (33.1%) were asymptomatic. EEG abnormalities consistent with cerebral ischemia occurred in 97 (26.3%) operations. The indwelling shunt (IS) was used in 73 cases; in the remaining 24 (24.7%), IS was not used on purpose because the surgical procedure was carried out successfully within 5-6 min after the appearance of EEG changes. All patients awoke from the anesthesia without any neurological deficit. Five patients presented with a major stroke within postoperative day 1 and 2, and 1 patient died on postoperative day 10. In 2 of these cases, the intraoperative EEG monitoring was absolutely normal and the IS was not used: the carotid occlusion was due to technical errors. The most striking finding of this series is the absence of false-negative results in continuous EEG monitoring. EEG monitoring appears an available and useful method for the detection of cerebral ischemia secondary to carotid cross-clamping and contributes to put at zero the intraoperative complications of the surgical procedure.

Adult↗

PubMed1997

Phenotype expression of gingival fibroblasts cultured on membranes used in guided tissue regeneration.

Human gingival fibroblasts were cultured in vitro using as substrates an extracellular matrix (matrix) and polytetrafluoride (PTFE) membranes, which are used in guided tissue regeneration. To test the degree of biocompatibility of these membranes, the cellular proliferation and the accumulation of extracellular matrix (ECM) macromolecules were considered as parameters. The fibroblasts were cultured in vitro for 24 and 48 hours without serum on plastic, matrix, and PTFE membranes in the presence of 3H-thymidine, 3H-glucosamine, and 3H-proline to study the neo-synthesis of DNA, glycosaminoglycans (GAG), and collagen proteins, respectively. Studies on cell proliferation showed that fibroblasts grown on matrix membrane significantly increased 3H-thymidine incorporation, while fibroblasts grown on PTFE membrane decreased 3H-thymidine incorporation, compared to plastic used as a control. Moreover, the PTFE membrane induced a marked decrease of collagen and GAG accumulation both in the cellular and extracellular pool, while the matrix membrane provoked a decrease of the two macromolecules in the cellular pool and an increase in the extracellular one, compared to the control. The data we obtained demonstrate that matrix membranes are the most suitable to stimulate both cellular proliferation and ECM macromolecule accumulation.

Adult↗

PubMed1997

[Bacterial infections in HIV patients].

AIM OF THE STUDY AND METHODS: Retrospective analysis of bacterial infections occurring in 400 admissions of HIV-positive patients in the Infectious Diseases Unit of the Azienda Ospedale Santa Corona, Pietra Ligure (SV), from January 1994 to September 1996. RESULTS: 56 episodes were documented (14% of admissions): 24 (43%) hospital acquired (11 sepsis, 5 pneumonias, 6 urinary-tract infections, 1 infection of a prosthetic device) and 32 (57%) community-acquired (9 sepsis, 13 pneumonias [6 with bacteremia] 9 urinary-tract infections, 1 endocarditis). At time of diagnosis mean absolute CD4-lymphocyte count was 106/cmm (95% Cl 62-150) and mean neutrophil count was 4.690/cmm (95% Cl 3.466-5.914); 11 patients had a central venous catheter, 9 a vesical catheter and 7 severe skin lesions. Methicillin-resistant S. aureus (11/24, 46%) and Pseudomonas (8/24, 33%) were the most frequently isolated pathogens in hospital infections, while the majority of community acquired episodes were due to S. pneumoniae (10/32, 31%). In six episodes (11%) the patient died because of the bacterial infection. CONCLUSIONS: Bacterial infections are quite frequent in this cohort of HIV-infected patients. Methicillin-resistant S. aureus and Pseudomonas represented the major cause of hospital acquired infections, while S. pneumoniae represented the major cause of community acquired episodes.

English Abstract↗

PubMed1997

[Etiopathogenic hypotheses on dental ankylosis].

The authors review the literature about the different etiopathogenetic hypotheses of tooth ankylosis. They classified the ankylosis in three big groups: traumatic ankylosis due to direct and indirect injuries to the tooth, iatrogenic ankylosis due to unadvised maneuvers made by the dentist, and atraumatic ankylosis. The last is the most important group caused by metabolic problems and with family characteristics. Furthermore they underline the important role played by GAG and corresponding lytic enzymes in the development of atraumatic ankylosis. They described, the therapeutical procedures to be used in the different cases. The clinical cases presented are representative of the different therapeutical approaches.

Ankylosis↗

PubMed1997

[Preservation of the anal sphincter in low rectal lesions].

We have discussed the surgical options to save the anorectal sphincter in lesions within the lower 2/3 of the rectum. We presented four clinical cases: two villous adenomas, one adenocarcinoma and one benign tumor, probably of embryonic origin. We discussed the surgical options in order to avoid a permanent colostomy. There is not a single surgical procedure that we can count on to preserve the anal sphincter, either in benign or malignant lesions. The surgeons treating this pathology should consider all options and be able to select the most adequate, the less complicated and yet be able to preserve continence. The surgeons should remember that in treating malignant lesions "a curative resection is worth a colostomy".

Adenocarcinoma↗

PubMed1996

Immunocompetence of T lymphocytes during whole-blood storage.

In WB stored for 28 days at 4 degrees C the pattern of peripheral T-cell CD25 (IL-2R) expression after polyclonal in vitro stimulation was examined. Flow cytrometic analysis was performed with lymphocytes after 72 h in culture with and without ConA using antibody against CD3 and CD25. In culture supernatants IL-2 was determined. T-cells bearing the CD25 marker decreased with storage time, the mean fluorescence (i.e., number of IL-2R molecules per cell) remained rather stable. IL-2 concentrations peaked with stimulated cells which have been stored for 6 days. The low detectable levels of IL-2 in cultures of T-cells which have not been stored may reflect a much more efficient interplay of IL-2/IL-2R. Thus, even after longer periods of blood storage there are sufficient numbers of T-cells which can be stimulated to excite preprogrammed effector functions, i.e. also a GVHD.

Blood Preservation↗

PubMed1996

Linkage of frontotemporal dementia to chromosome 17: clinical and neuropathological characterization of phenotype.

Frontotemporal dementia is a behavioral disorder of insidious onset and variable progression. Clinically, its early features reflect frontal lobe dysfunction characterized by personality change, deterioration in memory and executive functions, and stereotypical and perseverative behaviors. Pathologically, there is degeneration of the neocortex and subcortical nuclei, without distinctive features such as plaques, neurofibrillary tangles, or Pick or Lewy bodies. Within-family variation in neuropathology and clinical phenotype is observed. In cases where family aggregation is observed, it is inherited as an autosomal dominant, age-dependent disorder. Family studies recently have identified two dementia loci: chromosome 17 for disinhibition-dementia-parkinsonism-amyotrophic complex and pallido-ponto-nigral degeneration and chromosome 3 for familial nonspecific dementia. We describe a family (DUK1684) with clinically and neuropathologically confirmed, autosomal dominant, non-Alzheimer disease dementia. Linkage analysis of this family showed evidence for linkage to chromosome 17q21, with a multipoint location score (log10) of 5.52. A comparison of the clinical and pathological features in DUK1684 with those of the other chromosome 17-linked families, together with the linkage data, suggests that these families are allelic. These studies emphasize that genetic linkage analysis remains a useful tool for differentiating disease loci in clinically complex traits.

Age of Onset↗

PubMed1996

[Color loss evaluation of a dietary formulation in function of temperature, storage time and packaging].

Color loss of a dietetic formulae based on pumpkin (Cucurbita maxima), rice, hen and vegetable oils was evaluated. The product was under an accelerated test at temperatures of 40, 50 and 70 degrees C for a month. The kinetic reaction of color loss (quality loss indicator) was obtained with n = 1 and Ea = 11.5 Kcal/mol. The product was also stored for sixth months at temperatures of 25, 30, 35 and 40 degrees C using glass containers, laminated and composite cans (non metallic). The color was measured by a colorimetric method and by sensory evaluation under the defined conditions of time, temperature and package. The statistical analyses of the color loss measured by instrument was performed by a randomized block design with a significance level of p < 0.05. The results obtained both by the instrument and by the sensory evaluation method, showed that the temperature and storage time has significant effect (p < 0.05) on the other hand, the package does not have a significant effect. It was concluded from this study that the product could be stored for 6 months at temperatures below 35 degrees C without changes in color.

Color↗

PubMed1996

[Knowledge about AIDS prevention among professionals and students in health care].

This work is a exploratory research based on the analysis of the answers to the questionnaires of 52 students and health care professionals knowledge about AIDS sexual prevention, biosecurity, diagnosis tests, patients and workers rights and the modifications of nursing and medical care to this kind of disease.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Pulmonary arteriovenous fistula ruptured to pleural cavity in pregnancy.

Congenital pulmonary arteriovenous fistula is frequently associated with hereditary haemorrhagic telangiectasia (Rendu-Osler-Weber disease). With the increased blood flow in pregnancy such fistulas enlarge, occasionally giving rise to haemothorax, which generally has a poor prognosis. A familial case is presented in which massive haemothorax required emergency thoracotomy in the 27th week of pregnancy.

Adult↗

PubMed1995

Onset of clinical signs in children with HIV-1 perinatal infection. Italian Register for HIV Infection in Children.

OBJECTIVE: To investigate the timing of onset of each clinical sign in infants and children with HIV-1 perinatal infection. DESIGN AND METHODS: A total of 200 HIV-1-infected children followed-up from birth were studied. Failure and conditional probabilities were estimated by the Kaplan-Meier product-limit method. Cox proportional hazard analysis was used to evaluate independently associated factors. Results of 934 seroreverters were used to calculate reference values of CD4+ cell counts and predictivity of early signs. RESULTS: Median age at the onset of any sign was 5.2 months (range, 0.03-56 months). The probability of remaining asymptomatic was 19% [95% confidence interval (CI), 14-25.1] at 12 months and 6.1% (95% CI, 2.6-11.7) at 5 years. Lymphadenopathy (69.5%), splenomegaly (62.4%) and hepatomegaly (58.4%) were the most common signs in the first year of life. Peculiar to the first year of life (compared with subsequent ages) was the onset of primary HIV-1 hepatitis and diarrhoea (rate ratios, 23.3 and 15.2, respectively). When CD4+ cell counts in the asymptomatic stage (age, 2 months; range, 0.03-5.9 months) were below rather than above the fifth percentile in seroreverters, onset of signs was earlier [3 range, 0.03-19) versus 5 (range, 0.03-56) months]. Children manifesting signs before the 5.2-month breakpoint had a lower survival rate [74% (range, 65.9-82%) at 12 months and 45% (range, 32.9-57%) at 5 years] than children manifesting signs later [98% (range, 92.2-100%) at 12 months and 74% (range, 60.3-87.7%) at 5 years]. Children whose birthweight was < or = 2400 g had an earlier onset (24 months; range, 1-57 months) of severe conditions than children with higher birthweight (71 months; range, 1-71 months). Development of lymphadenopathy or hepatosplenomegaly within 3 months of life were reliable indicators of infection. CONCLUSIONS: This study describes the sequence of onset of signs in perinatal HIV-1 infection. Infection is shown to progress faster than in adults and in a different manner. Low birthweight, early decreased CD4+ cell counts, and early onset of signs are predictive of rapid progression.

AIDS-Related Complex↗

PubMed1995

Solid malignant neoplasms after childhood irradiation: decrease of the relative risk with time after irradiation.

The pattern of the temporal distribution of solid cancer incidence after irradiation in childhood is not well known, although, its importance in radioprotection is well known. We studied a cohort of 1,055 children from 8 European cancer centres, who received radiotherapy between 1942 and 1985 for a first cancer in childhood. After a mean follow-up of 19 years, 26 children developed a solid second malignant neoplasm (SMN), as compared to 5.6 expected from general population rates. Both the excess relative risk and the excess of absolute risk of solid SMN were higher among children who were younger at time of the irradiation. After reaching a maximum 15 to 20 years after irradiation, the excess relative risk of SMN decreased with time after irradiation, when controlling for age at irradiation and sex. The analysis of the risk of thyroid, brain and breast cancer together, as a function of the dose averaged on these 3 organs lead to similar results.

Adolescent↗

PubMed1995

[Size and echogenicity of the pancreas in Chilean adults: echotomography study in 261 patients].

The aim of this work was to perform ultrasonographic measurements of normal pancreas in the Chilean population. Among 5000 subjects referred for an ultrasound abdominal examination, those without history of alcoholism, pancreatitis or liver disease were selected for the study. 261 individuals (157 female) aged 20 to 79 years were studied. The size of the head of the pancreas ranged from 6 to 28 mm (17.7 +/- 4.2 mm), the body size ranged from 4 to 23 mm (10.1 +/- 3.8 mm) and the tail size from 5 to 28 mm (16.4 +/- 4.2 mm). These figures are lower than those reported in Europe and North America. No size differences were observed according to sex or body frame. Progressive declines in size with age, were observed in all pancreatic segments. No hypoecogenic pancreas were observed. A new technique to improve pancreatic ultrasonographic vision is proposed.

Adult↗

PubMed1995

[Osteopoikilosis. A clinical case].

We report a 35 years old female presenting with a right wrist pain. Physical examination was normal but, on a hand X ray examination, multiple dense para-articular bone foci were observed. Studying the rest of the skeleton, similar alterations were found in pelvis, knees, ankles, feet, shoulders and elbows. Osteopoikilosis is an infrequent sclerotic bone dysplasia. Its diagnosis is made by the observation of multiple dense, nodular and symmetrical images of para-articular location on bone X ray examinations. It has no clinical or pathological importance. Thus, it must be distinguished from osteoblastic bone metastases.

Adult↗

PubMed1995

[The use of deffated corn germ in flour manufactured to bakery products].

The flour of deffated corn germ is a by-product of the corn industry milling dried which is actually subutilized in human consumption. In this study, two samples of corn deffated germ of different particle size were physicochemically characterized: fine fraction (FF) and medium fraction (FM) and they were added to wheat flours to obtain composite flours with substitution levels of 5- 10- 12- 15% mixtures. These mixtures were used to manufacture sandwich bread in bakeries, which were physico-chemically and sensorially analyzed. (FF) and (FM) were found to provide from 20 to 35% of dietary fiber. From the manufactured bread loaves, the ones containing 10% of (FM) and 10% of (FF) were selected because they did not differ in specific weight, color, flavor and texture at a 95% confiability from those elaborated with 100% wheat flour. In the acceptability test given to 200 consumers, it was found that bread with 10% FF substitution was more widely accepted (48%) than that containing 100% wheat flour; and that of 10% of (FM) had the same level of acceptability (28%) as the control bread. It can be concluded that the deffated corn kernel represents a raw material available in this country that could be used in bread elaboration as a partial replacement for imported wheat.

Bread↗

PubMed1994

[The incidence of second neoplasms in advanced laryngeal cancer. Impact on survival].

BACKGROUND: The incidence of second neoplasms in laryngeal cancer is greater than that of other neoplasms. The appearance of a second neoplasm in these patients represents an important decrease in survival. The prevalence of second neoplasms in laryngeal cancer and its impact on survival was determined in this study. METHODS: Seventy-eight patients with advanced laryngeal cancer (stages III and IV of the UICC) who had been treated with erradicative surgery from January 1984 to December 1988; and who were attended in the Radiotherapy and Oncology Department of the Ciutat Sanitària i Universitària Vall d'Hebron were retrospectively studied. All were postoperatively submitted to radiotherapy. RESULTS: Ten of the 78 patients studied (13%) developed a second neoplasm. The most frequent localization was pulmonary (70%). In 9 of the 10 patients the appearance of the second neoplasm was considered metachronic with 60% being detected within the first 24 months after the diagnosis of the laryngeal neoplasm. The survival of the whole group was 80% at 2 years and 51% at 5 years. Survival of the patients with the second neoplasm was lower: 71% at 2 years and 5% at 5 years (p < 0.0001). CONCLUSIONS: The presence of a second neoplasm in patients with laryngeal cancer is high. The survival of patients with advanced laryngeal cancer who develop a second neoplasm is significantly lower than that of other patients with this neoplasm.

Adult↗

PubMed1994

Rapid detection of rotavirus in faeces using a dipstick system with monoclonal antibodies and colloidal gold as marker.

Rotavirus (RV) is known to be the most common cause of severe diarrhoea in infants and young children, each year leading to an estimated 800,000-900,000 deaths. RV also infects bovines and other species, with high morbidity and mortality. A rapid and simple 'naked-eye' dipstick system was developed to detect human RV in faeces, using nitrocellulose as solid phase, two monoclonal antibodies, and colloidal gold as marker. The system detects 10(4) viral particles (1-2 ng)/g of faeces. For human RV the specificity and sensitivity were 100% when compared with a commercial latex system, and 99% and 98%, respectively, when correlated with traditional RNA-PAGE, and 100% and 98% compared to an ELISA system.

Animals↗

PubMed1994

[Gallbladder polyps. 2d Consensus Workshop of the Chilean Hepatology Association].

During a workshop, hepatologists analyzed and gave recommendations about gallbladder polyps. They arrived to the following agreements: gallbladder polyps of less than 10 mm should be followed with ultrasonography at 3, 6 and 12 months if there is no enlargement. If there is enlargement, a cholecystectomy should be performed. Polyps larger than 10 mm should be subjected to cholecystectomy.

Female↗