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Biomedical subjects

J Serra

Publications and source records attributed to J Serra.

At least 73 records · Page 4Linked to original sources
PubMed1996

Axon reflexes or ephaptic responses simulating blink reflex R1 after XII-VII nerve anastomosis.

It has been claimed that functional recovery of the blink reflex occurs after hypoglossal-facial nerve anastomosis. This has been explained through central nervous system plasticity and reorganization of neuronal connections. In 5 patients with reinnervated facial muscles after hypoglossal-facial nerve anastomosis we observed "R1-like" responses that fulfilled criteria for facial nerve axon reflexes or ephapses. First, displacement of the stimulating electrode from the supraorbital to zygomatic area shortened the latency of the evoked response. Second, these responses were stable (jitter mean consecutive difference < 25 microsec) and they had complex potential shapes unmodified by high-frequency stimulation. Finally, collision techniques demonstrated antidromic conduction of impulses in the facial nerve from supraorbital to zygomatic points. Therefore, these "R1-like" responses are not the early component of a functionally recovered blink reflex but motor axon reflexes or ephaptic responses similar to the short latency responses observed following facial nerve regeneration or from sutured nerves in human forearms.

Adolescent↗
PubMed1996

Fatal chemical pneumonitis due to cadmium fumes.

Acute exposure to high concentrations of cadmium fumes may cause acute chemical pneumonitis with a possibly fatal outcome. The etiologic diagnosis of acute cadmium intoxication from inhaled fumes may be difficult and can be confused with other forms of acute respiratory failure. We report on a case of a fit 53 year-old man who was exposed to cadmium fumes after flame-cutting an alloy containing around 10% of cadmium for a period of 60-75 minutes. He developed severe chemical pneumonitis and died 19 days after exposure.

Cadmium↗
PubMed1996

Community-acquired pneumonia in chronic obstructive pulmonary disease: a Spanish multicenter study.

Community-acquired pneumonia (CAP) is an infectious illness that frequently motivates hospital admission when comorbid conditions are present. However, the epidemiology of CAP in relation to the underlying disease of the patients is not well known. We performed a prospective multicenter study with the aim of assessing the clinical characteristics, etiology, and outcome of chronic obstructive pulmonary disease (COPD) patients with CAP. Between October 1992 and December 1994 we studied 124 COPD patients (mean FEV1 40 +/- 11% of predicted, mean FVC/FEV1 49 +/- 10) admitted because of CAP to one of the participating centers. An attempt to obtain an etiologic diagnosis was performed by means of blood cultures (n = 123), sputum cultures (n = 97), pleural fluid cultures (n = 17), protected specimen brush samples (n = 41), percutaneous transthoracic needle aspiration (n = 41), and serology (n = 106). Etiologic diagnosis was achieved in 80 (64%) of cases, however, diagnosis based upon valid techniques was only possible in 73 (59%) cases. The main causal microorganisms were the following: Streptococcus pneumoniae in 32 (43%), Chlamydia pneumoniae in 9 (12%), Hemophilus influenzae in 7 (9%), Legionella pneumophila in 7 (9%), Streptococcus viridans in 3 (4%), Coxiella burnetii in 3 (4%), Mycoplasma pneumoniae in 2 (3%), Nocordia asteroides 2, Aspergillus ssp. 1, and others 10. In three of these cases the etiology was polymicrobial. Bacteremia was present in 19 (15%) cases; S. pneumoniae was the most frequent isolate (13 cases). Antibiotic treatment was modified in 22 cases due to etiologic findings, and in 9 due to therapeutic failure. Ten patients died (8%), and 22 needed mechanical ventilation, the mortality rate in the latter population being 23%. Total or partial resistance of S. pneumoniae to penicillin was observed in 10 of 32 (31%) isolations, and to erythromycin in 2 (6%). The results of this study are important for the standardization of empiric antibiotic strategies in COPD patients with pneumonia.

Aged↗
PubMed1996

Influence of coronary lesions morphology on treadmill exercise stress testing after acute myocardial infarction.

OBJECTIVES: To evaluate the influence of infarct related artery lesion morphology on the exercise stress test performed after a first myocardial infarction. METHODS: We reviewed coronary angiography and the exercise stress test performed before discharge from hospital in 105 consecutive patients (91.4% male, mean age 49.6 +/- 9.2 years) with first acute myocardial infarction. Complex coronary lesions were defined by the presence of one of the following characteristics: ulcers, thrombus, shoulders, irregularities and eccentricity. According to either the existence or absence of complex coronary lesions, two groups were considered: Group I--42 patients with complex coronary lesions, and Group II--47 patients without these characteristics in coronary angiogram. Sixteen pts (14%) were excluded because the infarct related artery was occluded or existence of complex lesions in other coronary artery not related to the infarct. Left ventricular systolic function was analyzed using the "CASS score". Exercise stress test performed between the 10th and the 15th day after myocardial infarction, using Bruce protocol, were reviewed. The following parameters were analyzed: exercise time, number of metabolic equivalent units (METS), maximal heart rate attained, double product variation and number of patients with significant ST segment depression and/or angina. RESULTS: No statistically significant differences between the two groups were obtained as far as age, sex, left ventricular function, number of diseased vessels and lesions severity. From the analysis of ergometric parameters we did not find any difference between the two groups of patients about exercise time (Group A--8.37 +/- 2.6 versus (vs) Group B 8.38 +/- 3.18), METS (Group A--8.22 +/- 2.87 vs Group B--8.13 +/- 2.97), maximal heart rate (Group A--88.2% vs Group B--87.5%) and double product variation (Group A--14547 +/- 5492 vs Group B--14553 +/- 5387). However, the number of ischemic response (defined by usual criteria of St-segment depression and/or angina) was significantly greater in patients with complex coronary lesions (ST--segment depression: Group A--26 pts vs Group B--19 pts, p < 0.05/Angina: Group A--16 pts vs Group B--4 pts, p < 0.001). Thus, complex coronary lesions are related to a high incidence of residual ischemic phenomena detected by electrocardiographic exercise stress test performed on predischarge period of acute myocardial infarction. Further studies will be necessary to show the prognostic value of particular angiographic characteristics found in coronary plaques.

Adult↗
PubMed1995

Gastric tone determines the sensitivity of the stomach to distention.

BACKGROUND/AIMS: Whether meal-related symptoms such as postcibal epigastric fullness and discomfort are caused by hypotonic gastric expansion or gastric hypertension is unknown. This study investigated whether symptoms in healthy individuals in response to gastric distention are produced by gastric expansion or by an increase in intragastric pressure. METHODS: Increasing gastric distentions (for 5 minutes at 5-minute intervals) at fixed pressure levels (in 2-mm Hg increments) and at fixed volume levels (in 200-mL increments) were performed in 10 healthy subjects per group; perception was measured on a 0-6 scale. Distentions were performed during intravenous infusion of saline (basal) and during gastric relaxation by intravenous administration of glucagon (4.8-micrograms/kg bolus plus 9.6 micrograms.kg-1.h-1 infusion). RESULTS: The same distending pressure tested produced 30% +/- 9% larger intragastric volumes and 80% +/- 44% higher perception scores when the stomach was relaxed by glucagon (P < 0.05 vs. basal for both). In contrast, the same distending volumes tested produced 25% +/- 7% lower intragastric pressures and 21% +/- 12% lower perception scores when the stomach was relaxed (P < 0.05 vs. basal for both). CONCLUSIONS: Epigastric symptoms in response to gastric distention are influenced by both the intragastric pressure and the intragastric volume.

Adult↗
PubMed1995

Perception and reflex responses to intestinal distention in humans are modified by simultaneous or previous stimulation.

BACKGROUND & AIMS: Intestinal reflexes induced by distention in dogs are facilitated by either simultaneous or previous distentions. The aim of this study was to determine whether these phenomena also modulate the responses to intestinal distention, particularly perception, in humans. METHODS: Perception and intestinal relaxation were measured in 11 healthy subjects in response to increasing jejunal balloon distentions tested (by stimulus-response trials) alone, as control, and with conditioning distentions applied either simultaneously, immediately (10 seconds) before at the same site, or immediately before and 5 cm distant. In 8 additional subjects, the effect of prolonged (90-minute) conditioning distention was tested. RESULTS: Conditioning had more pronounced effects on perception than on intestinal reflexes. Perception of intestinal distention increased (by 84 +/- 47%; P < 0.05) when a simultaneous distention was applied nearby. By contrast, perception decreased (by 38 +/- 12%; P < 0.05) when a previous distention was applied at the same but not at an adjacent site. Prolonged intestinal distention elicited remarkably stable perception during a 90-minute period. The effects of conditioning were unrelated to intestinal compliance because it remained unchanged. CONCLUSIONS: In humans, temporospatial interactions of gut stimuli activate modulatory phenomena that determine the perception intensity of the stimuli.

Adult↗
PubMed1995

Natural history of strictureplasty in Crohn's disease: 9-year experience.

OBJECTIVE: To study the short- and long-term outcomes in patients with Crohn's disease who have undergone strictureplasty. DESIGN: A retrospective review with a prospective follow-up (mean 54.4 months [range from 4 to 108 months]). SETTING: The Inflammatory Bowel Disease Centre at Mount Sinai Hospital in Toronto. PATIENTS: Forty-three patients (29 men, 14 women) who underwent 154 strictureplasties for Crohn's disease. The mean age of the patients was 32.5 years (range from 17 to 55 years). INTERVENTION: Strictureplasty by either the Heineke-Mikulicz (145 strictureplasties) or the Finney (9 strictureplasties) technique in the duodenum, small intestine and at the site of the previous anastomosis. MAIN OUTCOME MEASURES: Factors studied for symptomatic recurrence included the type of procedure previously performed, the type of strictureplasty, the number of previous operations and the site of the disease. RESULTS: There were no deaths. There was one documented leak. Twenty-six patients remained symptom free during the follow-up period. Fourteen patients required reoperation for progressive obstructive disease. None of the differences in the variables studied was statistically significant when related to the symptomatic recurrence rate. However, only 2 of 11 patients who had strictureplasty as the only procedure have required reoperation. CONCLUSIONS: Strictureplasty is a safe and useful procedure in the management of extensive obstructive Crohn's disease. Strictureplasty does not seem to alter the natural history of the disease.

Adolescent↗
PubMed1995

Renal angioscopy.

Explore the source record for details and available documents.

Accidents, Traffic↗
PubMed1995

Peribulbar anaesthesia: the role of local anaesthetic volumes and Thiomucase in motor block and intraocular pressure.

Peribulbar anaesthesia is a useful regional anaesthesia and akinesia technique for eye surgery. We studied changes in muscular akinesia and intraocular pressure under peribulbar anaesthesia caused by different volumes of 0.75% bupivacaine with or without the addition of Thiomucase (chondroitin sulphatase) in patients undergoing cataract surgery. A total of 120 patients were randomly allocated into four groups: group 1, bupivacaine 5 mL; group 2, bupivacaine 5 mL plus Thiomucase 10 U mL-1; group 3, bupivacaine 9 mL; group 4, bupivacaine 9 mL plus Thiomucase 10 U mL-1. We assessed: (1) akinesia according to mobility in the four quadrants of the eyeball and the palpebral opening using a scoring system between 0 (total akinesia) and 10 (full movement); and (2) intraocular pressure before, immediately after and 15 min after peribulbar anaesthesia. A significantly better motor blockade was observed in groups 2, 3 and 4 than in group 1 (P < 0.05). Thiomucase increased the quality of motor blockade in group 2, but not in group 4. Intraocular pressure increased by 5-10 mmHg in comparison with baseline values and, after 15 min application of Honan's balloon, decreased by 8-10 mmHg in comparison with baseline values, with no significant differences between groups. Thiomucase can improve the motor block if a lower volume of local anaesthetic is used. The administration of 5 or 9 mL volumes or the addition of Thiomucase decreases the the intraocular pressure in a similar way.

Aged↗
PubMed1994

Quantification of interstitial chronic renal damage by means of texture analysis.

There is a relationship between chronic renal damage and renal function at the time of biopsy. Since the quantification of interstitial lesions with morphometric techniques is very time consuming, a fully automatic method to quantify chronic damage is desirable. Progression of chronic renal damage could be viewed as a texture modification of tubulointerstitial structures. The aim of the present work is to study whether chronic renal damage could be automatically measured by means of texture analysis based on mathematical morphology. Among the morphological tools the best suited for our purpose is that of granulometry. Between four and six fields from 35 renal biopsies with different degrees of renal damage were stained with Sirius red and digitized under polarized light. In each field granulometric function with a circular structuring element was obtained. Interstitial volume fraction was measured with a point counting technique. Glomerular filtration rate at the time of biopsy was available in each case. A positive relationship between granulometric function and glomerular filtration rate was observed (r2 = 0.85). The determination coefficient between interstitial volume fraction and renal function was (r2 = 0.54). In conclusion, we describe a fully automatic method that precisely quantifies interstitial chronic renal damage.

Adult↗
PubMed1994

Thoracic disc herniation, cord compression, and paraplegia caused by electrical injury: case report and review of the literature.

The case of a patient with thoracic intervertebral disc prolapse, cord compression, and delayed paraplegia with recovery secondary to high-tension electrical current is presented. The unusual entry wound in the neck, makes this a rare event that to our knowledge has not been previously described in the literature. Magnetic resonance imaging allowed noninvasive and early diagnosis, and in the future probably will reveal the true incidence of cord compression in electrical injury victims.

Adult↗
PubMed1994

Histological response of Eptesicus serotinus (Mammalia: Chiroptera) to Argas vespertilionis (Acari: argasidae).

The sequential histological development of Argas vespertilionis (Acarina: Argasidae) feeding sites on Eptesicus serotinus (Mammalia: Chiroptera) was evaluated. Neutrophils, followed by Langerhans cells, were the major components of the cellular infiltrate throughout the earliest phase of tick infestation. The host tended to isolate the tick mouthparts by means of a progressive formation of epithelial tissue in the feeding cavity.

Adenosine Triphosphatases↗