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Biomedical subjects

A Serra

Publications and source records attributed to A Serra.

At least 55 records · Page 3Linked to original sources
PubMed2001

PECAM-1/IgG attenuates peroxynitrite-mediated extremity reperfusion injury.

OBJECTIVE: Neutrophil transendothelial migration, a key feature of skeletal muscle ischemia and reperfusion (I/R) injury, is mediated by the platelet endothelial cell adhesion molecule-1 (PECAM-1). Peroxynitrite anion, a toxic product of neutrophil superoxide anion and nitric oxide, contributes to oxidative skeletal muscle injury and can be quantified by measurement of protein tyrosine nitration after I/R. This study hypothesizes that administration of the PECAM-1/IgG antibody chimera will inhibit peroxynitrite-mediated injury after I/R. METHODS: The study was composed of five groups: an I/R group (n = 4), a sham treatment group anesthetic control (n = 3), a treatment group receiving the PECAM-1/immunoglobulin G (IgG) antibody chimera with I/R (n = 9), a treatment group receiving human IgG with I/R as an antibody control (n = 6), and a treatment group receiving normal saline solution with I/R as a vehicle control (n = 5). The right hind limb in male New Zealand white rabbits was rendered ischemic by occluding the iliac and femoral arteries for 3 hours, followed by 2 hours of reperfusion (I/R). Sham-treated rabbits underwent arterial dissection without arterial occlusion. PECAM-1/IgG-treated rabbits and IgG-treated rabbits received an infusion of 1 mg/kg in normal saline solution 20 mL via an ear vein catheter during the last 5 minutes of ischemia and the first 15 minutes of reperfusion. Saline solution-treated rabbits similarly received normal saline solution 20 mL. The anterior tibialis muscle was harvested after reperfusion. Immunohistochemical staining for nitrotyrosine was performed with monoclonal antinitrotyrosine antibodies and fluorescently labeled secondary antibodies. Computed morphometric study was performed to calculate relative fluorescence scores for each histologic section. Averaged fluorescence scores were analyzed by one-way analysis of variance with Bonferroni post hoc comparison. RESULTS: The averaged fluorescence scores (mean +/- SEM) for the sham-treated (2.88 +/- 0.78) and PECAM-1/IgG-treated (6.16 +/- 0.43) groups demonstrated a significant reduction in quantitative fluorescence compared with the IgG- (15.17 +/- 2.01) and saline solution-treated (17.46 +/- 3.71) control groups, and the I/R-treated (18.52 +/- 3.00) group, (P <.05). CONCLUSIONS: These results suggest that PECAM-1/IgG diminishes peroxynitrite-mediated oxidative skeletal muscle injury by inhibiting neutrophil transendothelial migration and may therefore prove a useful therapeutic agent in the treatment of reperfusion injury.

Animals↗
PubMed2001

A prospective study evidencing rhinomanometric and olfactometric outcomes in women taking oral contraceptives.

BACKGROUND: The aim of this prospective study was to evaluate the changes in olfactory sensitivity of oral contraceptive (pill) users. METHODS: Sixty women underwent rhinomanometric and olfactometric determinations during the follicular, periovular and luteal phases of the menstrual cycle, and at day 7, 14 and 21 of contraceptive intake. Thirty-one women used 30 microg ethinyl oestradiol plus 75 microg gestodene and 29 women used 20 microg ethinyl oestradiol plus 150 microg desogestrel. RESULTS: Rhinomanometry showed higher but not statistically significant values during the periovular phase than in the follicular and luteal phases. Olfactometry showed a higher sensitivity during the follicular and periovular phases than during the luteal phase of the menstrual cycle. The rhinomanometric surveys in pill users were statistically different from those of the luteal phase (P < 0.02) and the follicular and periovular phases (P < 0.001). The olfactometric thresholds during the period of contraceptive use were statistically different from those of the follicular phase for a few odorous substances, and from those of the periovular phase for each odorous substance, but similar to those of the luteal phase (P = NS). CONCLUSIONS: Unlike the rhinomanometric airflow and trans-nasal pressure, the olfactory threshold to odours seems to depend on the variations of the ovarian steroids during the menstrual cycle and on the iatrogenic effects of oral contraceptives.

Adolescent↗
PubMed2001

Tonometry after laser in situ keratomileusis treatment.

PURPOSE: To assess the reliability of intraocular pressure measurements by Goldmann applanation tonometry versus pneumotonometry after laser in situ keratomileusis for myopia. PATIENTS AND METHODS: In this prospective study, corneal Goldmann applanation tonometry and pneumotonometry measurements were made in 118 eyes of 60 patients before and 1 and 3 months after undergoing laser in situ keratomileusis for myopia. Manifest refraction, ultrasonic corneal thickness measurements, and keratometry readings were also obtained. RESULTS: Preoperative intraocular pressure showed a good correlation between Goldmann applanation tonometry and pneumotonometry values (Pearson r = 0.71; P < 0.001). although Goldmann applanation tonometry readings were slightly higher at low intraocular pressure values and slightly lower at high intraocular pressure values. After a mean stromal ablation depth of 77.1 microm, mean intraocular pressure by Goldmann applanation tonometry decreased significantly (P < 0.001) from a preoperative value of 14.8 +/- 11.9 mm Hg to 11.9 +/- 2.1 mm Hg and 11.7 +/- 1.7 mm Hg after 1 and 3 months, respectively. Mean pre- and post-laser in situ keratomileusis measurements by pneumotonometry were similar (P = 0.8). Differences of postoperative intraocular pressure measurements by Goldmann applanation tonometry and pneumotonometry were statistically significant. After 3 months, there was a poor correlation between Goldmann applanation tonometry and pneumotonometry intraocular pressure values (Pearson r = 0.58). Postoperative intraocular pressure decrease in applanation tonometry correlated with changes in keratometry, spherical equivalent, and central corneal thickness. Regression analysis showed a decrease of 2.9 mm Hg per 70 microm reduction in central corneal thickness. CONCLUSIONS: Contact pneumotonometry measures the IOP reliably after laser in situ keratomileusis for myopia, whereas Goldmann applanation tonometry underestimates the intraocular pressure. This may be important in the treatment of any future glaucoma.

Adult↗
PubMed2001

Psychological factors and visual fatigue in working with video display terminals.

OBJECTIVES: To examine the part played by psychological factors in complaints about visual health reported by banking officers who work at video display terminals (VDTs). METHODS: Out of a population of 385 bank workers, a group of 212 subjects without organic visual disturbances (as determined by ophthalmological examination) who share a work environment and job duties was selected. Three questionnaires were administered to these subjects: (a) the NIOSH job stress questionnaire; (b) a questionnaire investigating subjective discomfort related to environmental and lighting conditions of the workplace; (c) a questionnaire on the existence of oculovisual disturbances. Correlation and multiple regression analyses were performed to examine for the presence of predictors of asthenopia. RESULTS: Social support, group conflict, self esteem, work satisfaction, and underuse of skills were found to be predictors of visual complaints; social support played a part also as a moderating factor in the stress and strain model; this model accounted for 30% of the variance. Subjective environmental factors, although in some cases significantly correlated with asthenopia, were not found to be strong predictors of the symptoms. CONCLUSIONS: Some part of the complaints about visual health reported by VDT workers are likely indirect expressions of psychological discomfort related to working conditions.

Adult↗
PubMed2001

Multiple rostral medullary nuclei can influence breathing in awake goats.

The purpose of this study was to determine the effect on breathing of neuronal dysfunction in the retrotrapezoid (RTN), facial (FN), gigantocellularis reticularis (RGN), or vestibular (VN) nuclei of adult awake goats. Microtubules were chronically implanted to induce neuronal dysfunction by microinjection of an excitatory amino acid (EAA) receptor antagonist or a neurotoxin. The EAA receptor antagonist had minimal effect on eupneic breathing, but 8--10 days after injection of the neurotoxin, 7 of 10 goats hypoventilated (arterial PCO(2) increased 3.2 +/- 0.7 Torr). Overall there were no significant (P > 0.10) effects of the EAA receptor antagonist on CO(2) sensitivity. However, for all nuclei, > or =66% of the antagonist injections altered CO(2) sensitivity by more than the normal 12.7 +/- 1.6% day-to-day variation. These changes were not uniform, inasmuch as the antagonist increased (RTN, n = 2; FN, n = 7; RGN, n = 6; VN, n = 1) or decreased (RTN, n = 2; RGN, n = 3; VN, n = 2) CO(2) sensitivity. Ten days after injection of the neurotoxin into the FN (n = 3) or RGN (n = 5), CO(2) sensitivity was also reduced. Neuronal dysfunction also did not have a uniform effect on the exercise arterial PCO(2) response, and there was no correlation between effects on CO(2) sensitivity and the exercise hyperpnea. We conclude that there is a heterogeneous population of neurons in these rostral medullary nuclei (or adjacent tissue) that can affect breathing in the awake state, possibly through chemoreception or chemoreceptor-related mechanisms.

2-Amino-5-phosphonovalerate↗
PubMed2001

Mortality after carotid body denervation in rats.

Carotid body denervation (CBD) in neonatal goats and piglets results in minimal irregular breathing and no fatalities. Redundancy and/or plasticity of peripheral chemosensitivity and a relatively mature ventilatory control system at birth may contribute to the paucity of CBD effects in these species. In the present study, we tested the hypothesis that CBD mortality would be greater in neonates of a less mature species such as the rat. We found that the mortality in rats denervated at 2-3 and 7-8 days of age was significantly higher (P < 0.05) than in sham-CBD rats. In all surviving rats, pulmonary ventilation during hypoxia was lower in CBD than in sham operated rats 2 days after denervation. In surviving rats denervated during the 7th and 8th postnatal days, there was also reduced weight gain and pulmonary ventilation during eupnea, including apneas up to 20 s in duration. However, the effects of CBD were compensated within 3 wk after denervation. Local injections of NaCN indicated that aortic chemoreceptors might have been one of the sites of recovery of peripheral chemosensitivity. We concluded that CBD has higher mortality in newborn rats than in other mammals, possibly because of the relative immaturity of these animals at birth. Nonetheless, in survivors there was enough redundancy and plasticity in the control of breathing to eventually compensate for the consequences of CBD.

Age Factors↗
PubMed2001

Holoprosencephaly (lobar form) associated with bilateral vocal cord palsy.

There have been many causes associated with bilateral vocal cord palsy, both congenital and perinatal. Until now, the main congenital causes of bilateral vocal cord palsy have been associated with meningomyelocele, Arnold-Chiari malformation, and hydrocephalus. We report a patient with bilateral vocal cord palsy associated with the lobar form of holoprosencephaly. In this case, bilateral vocal cord palsy was caused by the disruption of the cortical laryngeal motoneurons. Neonatal stridor must be carefully evaluated by the neonatologist to exclude severe cerebral anomalies.

Female↗
PubMed2001

[Canaud central venous catheters: 4-year experience].

BACKGROUND: The use of central venous catheters for permanent vascular access has become increasingly important because of the characteristics and the clinical problems of incident patients or patients already undergoing chronic hemodialysis. In this study a short and medium term evaluation was made of a double permanent central venous catheter positioned in the right internal jugular vein. The Canaud catheter was evaluated both from the point of view of practical use and for various technical and clinical problems. METHODS: During the observation period, July 1995 - September 1999, these catheters were used in 39 patients (mean age 72 years), 22 females and 17 males; 31% were diabetic patients and 46% were older than 75 years. Forty-five catheters were positioned with an average dwelltime of 347 days. RESULTS: Utilization was almost immediate and the resulting blood flow was suitable for all depurative techniques (blood flow more than 250 ml/min), with an average recirculation of 11.9% and an average resistance index of 0.54. Among the most serious complications during surgery a respiratory block was observed followed by the complete recovery of the patient. Some clinical complications were noted (5 venous thrombosis), as were some technical ones: 12% well as related to problems with the adapter, 24.3% to reversible thrombosis of the catheters occurred in 23 catheters in 22 patients. Infections. CONCLUSIONS: Overall Canaud catheters appear to represent a valid alternative to other more recent catheters for permanent vascular access. If necessary, they can be easily substituted due to the absence of a subcutaneous cuff.

Aged↗
PubMed2000

A longitudinal study of T1 hypointense lesions in relapsing MS: MSCRG trial of interferon beta-1a. Multiple Sclerosis Collaborative Research Group.

BACKGROUND: T1 hypointense lesions (T1 black holes) are focal areas of relatively severe CNS tissue damage detected by MRI in patients with MS. OBJECTIVE: To determine the natural history of T1 hypointense lesions in relapsing MS and the utility of T1 hypointense lesions as outcome measures in MS clinical trials. METHODS: MR studies were from the Multiple Sclerosis Collaborative Research Group trial. Longitudinal results are reported in 80 placebo- and 80 interferon beta-1a (IFNbeta-1a)-treated patients with mild to moderate disability relapsing-remitting MS. RESULTS: There was a small but significant correlation between T1 hypointense lesion volume and disability at baseline and on trial (r = 0.22, r = 0.28). In placebo patients there was a 29.2% increase in the mean volume of T1 hypointense lesions (median 124.5 mm3) over 2 years (p < 0.001 for change from baseline), as compared to an 11.8% increase (median 40 mm3) in the IFNbeta-1a-treated patients (change from baseline not significant). These treatment group comparisons did not quite reach significance. The most significant contributor to change in T1 hypointense lesions was the baseline number of enhancing lesions (model r2 = 0.554). Placebo patients with more active disease, defined by enhancing lesions at baseline, were the only group to show a significant increase in T1 hypointense lesion volume from baseline. CONCLUSION: The development of T1 hypointense lesions is strongly influenced by prior inflammatory disease activity, as indicated by enhancing lesions. These results suggest that treatment with once weekly IM IFNbeta-1a (30 mcg) slows the 2-year accumulation of these lesions in the brain.

Adjuvants, Immunologic↗
PubMed2000

Important role of carotid chemoreceptor afferents in control of breathing of adult and neonatal mammals.

This review provides a summary and prospective on the importance of carotid/peripheral chemoreceptors to the control of breathing during physiologic conditions. For several days after carotid body denervation (CBD), adult mammals hypoventilate (+10 mmHg increase in Pa(CO(2))) at rest and during exercise and CO(2) sensitivity is attenuated by about 60%. In addition, if the rostral ventrolateral medulla is cooled during NREM sleep after CBD, a sustained apnea is observed. Eventually, days or weeks after CBD, a peripheral ventilatory chemoreflex redevelops and there is a normalization of breathing (rest and exercise) and CO(2) sensitivity. The site (s) of the regained chemosensitivity has not been established. This plasticity/redundancy after CBD appears greater in neonates than in adult mammals. These data suggest the carotid and other peripheral chemoreceptors provide an important excitatory input to medullary respiratory neurons that is essential for breathing when wakeful stimuli and central chemoreceptors are absent.

Aging↗
PubMed2000

Non-confluent pulmonary arteries in a patient with pulmonary atresia and intact ventricular septum: ? A 5th aortic arch with a systemic-to-pulmonary arterial connection.

Major abnormalities of pulmonary circulation are uncommon in the patient with pulmonary atresia and intact ventricular septum. Non-confluent pulmonary arteries have only rarely been described in this setting. In this case report, we describe a patient in whom the pulmonary arteries are non-confluent, with the right pulmonary artery supplied through a right-sided arterial duct, and the left pulmonary artery most likely through a fifth aortic arch, thus providing a systemic-to-pulmonary arterial connection. We discuss the various forms of non-confluent pulmonary arteries in the setting of pulmonary atresia and intact ventricular septum.

Aorta, Thoracic↗
PubMed2000

Assessment of peripheral blood lymphocyte subsets in idiopathic myelofibrosis.

The objective of this study was to contribute to a better characterization of the immunological profile of idiopathic myelofibrosis (IM) at presentation by analysing the blood lymphocyte subsets and their possible correlations with other disease features. Absolute blood lymphocytes and lymphocyte subsets were assessed in 31 IM patients, compared with those from 34 healthy individuals, and correlated with the patients' main clinical, hematological and bone marrow histologic features. The mean lymphocyte count of the IM patients was 1.1 (SD 0.6) x 10(9)/L, versus 1.6 (SD 0.49) x 10(9)/L in controls (p = 0.0006), with 24 of the 31 patients (77.4%) showing lymphocytopenia (< 1.5 x 10(9)/L). IM patients had significantly lower counts of CD3, CD4, CD8, and CD3 -/ CD56+ cells, and significantly higher CD3 +/CD56 + lymphocyte counts. Although no significant differences were found between patients and controls with regard to CD19+/CD5+ cell counts, increased CD5 + B-cell lymphocytes were observed in three IM patients. In one of the latter patients, Ig gene rearrangement analysis of the heavy chain gene demonstrated such a subpopulation to be clonal, but the patient did not develop features of chronic lymphoid leukemia during a 5-yr follow-up. No correlation was found between the patients' blood lymphocyte counts and other disease features. We conclude that most IM patients have absolute lymphopenia, decreased T cells and increased cytotoxic T cells at diagnosis, and 10% of them show an increased CD5 + B-cell subpopulation.

Adult↗
PubMed2000

[Permanent central venous catheters for dialysis. The situation in Piedmont-Aosta Valley].

BACKGROUND: Permanent central venous catheters for hemodialysis have become increasingly important as vascular accesses for extracorporeal dialysis. The aim of this study was to evaluate the prevalence and various aspects of these catheters in the chronic dialysis population in Piedmont and Aosta Valley on 30-6-1998 using a multiple-choice questionnaire. METHODS: A total of 2389 patients were receiving chronic hemodialysis. Permanent central venous catheters were present in 6.2% of the population (149 patients), arteriovenous fistulas in 83.1%, vascular prostheses in 9.3% and temporary catheters in 1.4%. The site chosen for permanent catheters was the internal jugular vein in 88.6% of cases, the subclavian vein in 8.7% of cases and the femoral vein in 2.7% of cases. The double catheter is the most frequently used. In 76% of centres catheters are positioned by nephrologists. Thrombosis prophylaxis is performed in 98% of cases with heparin and the most frequently used disinfectant to dress the cutaneous exit is iodopovidone. RESULTS: This study highlights the important role played by permanent catheters. The double catheter was used in 64.4% of the entire population, confirming the greater efficiency of these catheters as reported in the literature. Operating autonomy is relative in 76.2% of centres where catheters are positioned by nephrologists who often use the collaboration of other specialists. CONCLUSIONS: The authors stress the need to reflect on the use of iodopovidone is to dress the cutaneous exit of catheters since this disinfectant is contraindicated by one of the largest manufacturers of silicone catheters owing to its harmful medium long-term effects.

Adult↗
PubMed2000

Maternity advice survey: sleeping position in Eastern Europe. MAS Study Group for WHO EURO region.

AIM: To identify hospitals in Eastern Europe promoting front infant sleeping position. METHODS: Questionnaires were distributed to maternity units in 22 countries during July to November 1999. RESULTS: A total of 489 hospitals in 20 countries responded. Preferred position in normal care units was back (26.6%), front (1. 8%), side (65%), or combination/none (6.6%). Corresponding recommendations at discharge were 17.4%, 3.5%, 73%, and 6.1%.

Benchmarking↗
PubMed2000

The usefulness of conventional and echo colour Doppler sonography in the differential diagnosis of toxic multinodular goitres.

OBJECTIVE: To assess the potential role of conventional sonography and colour flow Doppler (CFD) sonography (CFDS) in the differential diagnosis of toxic multinodular goitres. SUBJECTS AND METHODS: We investigated 55 patients with untreated hyperthyroidism (24 with typical toxic diffuse goitre of Graves' disease (Group A); 26 with multinodular goitre (Group B); and five with single toxic adenoma (Group C); 22 euthyroid subjects (12 with non-toxic multinodular goitre (Group D) and ten normal subjects (Group E)) were included as controls. In all cases free thyroxine, free tri-iodothyronine, TSH, TSH receptor antibodies (TRAb), anti-thyroperoxidase antibody, anti-thyroglobulin antibodies and anti-thyroid microsomal antibodies were determined and a [(99m)Tc]pertechnetate thyroid scan was performed. RESULTS: Patients with toxic multinodular goitre displayed two different CFDS patterns: 18 patients (Group B-1) had nodules with normal vascularity surrounded by diffuse parenchymal hypoechogenicity with markedly increased CFD signal and maximal peak systolic velocity (PSV) (a pattern similar to Group A patients with Graves' disease); eight patients (Group B-2) had increased intra- and perinodular CFD signal and PSV with normal extranodular vascularity (a pattern similar to that found in Group C patients with single toxic adenoma). Patients of Group B-1 showed a proportion of clinically evident thyroid ophthalmopathy, positive TRAb and other thyroid autoantibodies similar to that observed in Group A patients, while no evidence of thyroid autoimmunity was found in Group B-2. Sixteen out of 18 (89%) patients from Group B-1 displayed a scintiscan pattern of diffuse uneven radionuclide distribution, while seven out of eight (87.5%) of those from Group B-2 had localized uptake in multiple discrete nodules. Taken together, these data strongly suggest that Group B-1 mostly represents patients with the multinodular variant of Graves' disease, while Group B-2 represents patients with non-autoimmune toxic multinodular goitre. CONCLUSIONS: This study shows that combined conventional sonography and CFDS may easily distinguish nodular variants of Graves' disease from non-autoimmune forms of toxic multinodular goitre and confirms the clinical usefulness of this technique in the first-line evaluation of hyperthyroid patients.

Adolescent↗