Biomedical subjects

A Nader

Publications and source records attributed to A Nader.

At least 19 recordsLinked to original sources

PubMed2004

[Minimally invasive, safe treatment of the neurogenic bladder with botulinum-A-toxin in children with myelomeningocele].

PURPOSE: The efficacy and durability of botulinum-A toxin in the treatment of detrusor hyperreflexia in myelomeningocele (MMC) children was evaluated prospectively. MATERIALS AND METHODS: A total of 15 children (10 male and 5 female, mean age 5.8 years), all on clean intermittent catheterisation (CIC) due to MMC, were "non responders" to orally and intravesically administered anticholinergic medication. Pretreatment assessment included a videourodynamic evaluation, incontinence scoring and a mercaptoacetyltriglycine-3 renal scan. We injected from 10 U/kg up to a maximum of 360 U botulinum-A toxin at 25-40 sites of the detrusor, sparing the trigone. Follow-up was 24 months. All children had a urodynamic reevaluation with assessment of bladder capacity and incontinence score at 3, 9 and 12 months. RESULTS: Mean bladder reflex volume increased from 72.00 +/- 28.12 ml to 298 +/- 32.45 ml (p < 0.001). The maximal detrusor pressure decreased from 78.76 +/- 23.14 cm H(2)O to 42.76 +/- 24.34 cm H(2)O (p < 0.001). Maximal bladder capacity increased from 136.34 +/- 45.71 ml to 297.02 +/- 87.17 ml (p < 0.001). Detrusor compliance increased from 18.29 +/- 27.19 ml/cm H(2)O to 51.17 +/- 38.17 ml/mmH(2)O (p < 0.001). While 10 patients became completely dry between CIC, the remaining 2 patients improved from score 3 to 1. Results at 9 months were similar to the ones at 3 months. The mean efficacy and durability of the toxin was 10.5 months after the first intravesical injection. CONCLUSIONS: Botulinum-A toxin is a safe alternative in the management of detrusor hyperreflexia in MMC children. Preliminary results are promising concerning urodynamic parameters and continence.

Botulinum Toxins, Type A↗

PubMed2003

Mineralized microstructure of calcified avian tendons: a scanning small angle X-ray scattering study.

The micrometer level spatial distribution of the size, shape, and orientation of mineral crystallites in the calcifying matrix of tendons near the edge of the mineralizing front was investigated by scanning small angle X-ray scattering using synchrotron X-ray radiation. Using a special microbeam arrangement enabling 20 microm beam resolution and short measurement times, linear diffraction scans were made on sections from the normally calcifying tendons (tibialis cranialis) from the domestic turkey, which calcify in the distal to proximal direction. A change in shape and arrangement of mineral crystals was observed within the first 200 microm of the mineralization front, and the mineral crystal distribution was highly anisotropic with crystals aligned parallel to the fiber axis. In a cross-section of the tendon cut at right angles to the fiber axis, the orientation distribution of crystals was not azimuthally symmetric, and showed a small but nonzero anisotropy and a continuous change in mean orientation angle across the width of the tendon cross-section.

Animals↗

PubMed2001

Pelvic pain.

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Journal Article↗

PubMed2001

2 Years' experience with inspiratory muscle training in patients with neuromuscular disorders.

PURPOSE: The aim of our study was to assess the long-term effects of specific inspiratory muscle training (IMT) in patients with neuromuscular disorders (NMDs) who have various degrees of respiratory impairment. PATIENTS AND METHODS: Twenty-seven patients with NMDs (Duchenne's muscular dystrophy, 18 patients; spinal muscular atrophy, 9 patients) underwent 24 months of IMT. Patients were divided into three groups according to their vital capacity (VC) values. VC was measured as the parameter for the respiratory system involvement of the disease. Maximal inspiratory pressure (PImax) was assessed as the parameter for respiratory muscle strength, and the results of the 12-s maximum voluntary ventilation test (12sMVV) were assessed as the parameter for respiratory muscle endurance. Pulmonary and inspiratory muscle function parameters were assessed 6 months before training, at the beginning of training, and then every 3 months. RESULTS: The PImax values improved in group A (VC, 27 to 50% predicted) from 51.45 to 87.00 cm H(2)O, in group B (VC, 51 to 70% predicted) from 59.38 to 94.4 cm H(2)O, and in group C (VC, 71 to 96% predicted) from 71.25 to 99.00 cm H(2)O. The 12sMVV values improved in group A from 52.69 to 69.50 L/min, in group B from 53.18 to 62.40 L/min, and in group C from 59.48 to 70.5 L/min. For all three groups, there was a significant improvement of PImax (p < 0.007) and 12sMVV (p < 0.015) until the 10th month when a plateau phase was reached with no decline in the following month until the end of training. CONCLUSION: With IMT, respiratory muscle function can be improved in the long term of up to 2 years.

Adolescent↗

PubMed2000

Dose-dependent effects of inspiratory muscle training in neuromuscular disorders.

The goal of this study was to show whether a correlation exists between the intensity of specific respiratory muscle training and the improvement of strength and endurance in inspiratory musculature in patients with neuromuscular disorders (NMD). Sixteen patients with NMD (13 with Duchenne muscular dystrophy and 3 with spinal muscular atrophy) performed inspiratory muscle training (IMT) at home with a special training apparatus for 9 months. Maximal inspiratory mouth pressure (PI(MAX)) and 12s-maximum voluntary ventilation (12s-MVV) test served as parameters for inspiratory muscle strength and endurance, respectively. In patients whose inspiratory vital capacity (VC(in)) declined by less than 10% during the year before training began (n = 10), a significant positive correlation was found between the number of successfully completed strength and endurance exercises and the improvement of PI(MAX) (P < 0.05) and 12s-MVV (P < 0.05). In patients whose VC(in)-decline exceeded 10% (n = 6), indicating more progressive respiratory system involvement of the disease, no significant correlation between the improvement of PI(MAX) and 12s-MVV and the intensity of training was found. In patients with NMD, the effects of IMT-runs are dose-dependent, provided that the respiratory system involvement of the disease is only slowly progressive.

Adolescent↗

PubMed1999

Clinicopathogenetic significance of chromosomal abnormalities in patients with blastic peripheral B-cell lymphoma. Kiel-Wien-Lymphoma Study Group.

So far, reproducible histomorphologic and immunological criteria to distinguish clinicopathologic subtypes of blastic peripheral B-cell non-Hodgkin's lymphoma (BBCL), especially centroblastic (cb) and immunoblastic (ib) lymphomas, for daily diagnostic use are still lacking. Therefore, we correlated the cytogenetic findings in 126 patients with BBCL with histopathologic diagnoses. Subclassification of cb and ib lymphomas relied on the criteria defined in the updated Kiel classification; these subtypes are also listed in the Revised European-American Lymphoma (REAL) classification and in a preliminary report on the newly established World Health Organization classification, to investigate their clinical significance. Moreover, we performed a multivariate analysis to compare the prognostic significance of cytogenetic findings with the International Index. There were significant differences in the frequency of chromosome aberrations between different BBCL subtypes: t(8;14) was predominantly present in Burkitt's lymphomas, t(14;18) in centroblastic lymphomas, deletions in 8q and 14q, changes of 4q and losses of chromosome 10 in immunoblastic lymphomas; t(11;14) was restricted to blastoid mantle cell lymphomas and associated with a poor prognosis. In cb lymphomas, deletions in 1q42-qter, duplications in 1q23-32, trisomy 5, and changes of 15q were identified as independent prognostic factors. In ib lymphomas, changes of 7q and 8q had stronger impact on survival than the International Index. These findings underline that Burkitt's, cb, ib, and blastoid mantle-cell lymphoma are biologically distinct and clinically relevant entities and that cytogenetic findings can be helpful to subtype BBCL.

Biomarkers, Tumor↗

PubMed1999

Scanning small angle X-ray scattering analysis of human bone sections.

Scanning small-angle X-ray scattering (scanning SAXS) was applied for the first time on bone to compare results from SAXS directly with those from other position-sensitive methods, such as light and polarized light microscopy, back-scattered electron imaging, and radiographic imaging. Since scanning SAXS is a nondestructive method of investigation, images from all these techniques could be obtained from the same bone sections. Thus, it could be shown that both the collagen and the mineral crystals were predominantly aligned parallel to the trabeculae and, therefore, to principle stress directions. Moreover, the mean crystal thickness as determined by scanning SAXS was found to be different at various positions inside the trabecular and cortical structure. Finally, it could be shown that scanning SAXS is suitable for detecting local changes in bone material, e.g., due to fluoride treatment.

Adolescent↗

PubMed1999

Pharmacologic intervention during the acute bleeding episode.

The risk of recurrent variceal bleeding after an acute episode of bleeding has been controlled in significant with rebleeding rates as high as 80% between one and two years. Pharmacologic therapy has a definite role in the prevention of recurrent variceal bleeding and should be started as soon as the acute bleeding event has been controlled. Serial hemodynamic measurements are critical for success. Non-selective beta-blocker therapy is a reasonable first line approach followed by the addition of a long-acting nitrate for patients not achieving a 20% reduction in the hepatic venous pressure gradient. Most patients will require combination pharmacotherapy or combined endoscopic therapy with pharmacotherapy.

Acute Disease↗

PubMed1999

Pharmacological prevention of rebleeding.

Pharmacologic therapy used during acute variceal bleeding may control the bleeding episode, minimized transfusion requirements, and prevent early rebleeding. Several options for pharmacologic therapy exist in this setting and include: vasopressin in combination with nitroglycerin, terlipressin, somatostatin, and octreotide. Metoclopramide and domperidone may also be useful but require additional study. At present, octreotide, administered intravenously as soon as variceal bleeding is suspected, is favored.

Adrenergic beta-Antagonists↗

PubMed1999

[Osteoporosis and metabolic bone diseases; clinical relationship].

Metabolic bone diseases with disturbed bone remodeling lead to loss of biomechanical quality and atraumatic fractures. Differential diagnosis, prevention and adequate treatment should already start early in the course of these disorders to prevent fractures. Thus, clinical osteology is more than the simplified connection "low bone mineral density--fractures--osteoporosis". This review summarizes physiological relations between bone tissue and calcium homoeostasis as well as the relation between structure and function. In addition, the main metabolic osteopathies "osteoporosis, primary hyperparathyroidism and osteomalacia" are presented from a clinical point of view. The importance and the diagnostic values of biochemical parameters and of the transiliacal biopsy are discussed. In this respect the quantitative measurement of the mineralization density (bone mineral density distribution = BMDD) seems to be of high value and extends the well established bone histomorphometry. This recently introduced method has the power to distinguish between small differences in the degree of mineralization of the matrix with high precision and reproducibility. The results of quantitative backscattered electron imaging in the scanning electron microscope improve the differential diagnosis of bone diseases with alterations in mineralization density, helps to detect mixed etiology (e.g. osteoporosis plus osteomalacia) and facilitate decision making for treatments. The value of biochemical, radiological, osteodensitometric and histopathological tests for diagnosis and treatment depends on the knowledge of the clinical relations and the complex interactions between calcium-, phosphate- and bone metabolism.

Age Factors↗

PubMed1996

Cytogenetic findings in 175 patients indicate that items of the Kiel classification should not be disregarded in the REAL classification of lymphoid neoplasms.

Cytogenetics have proved to be a valuable tool for classifying systemic lymphatic neoplasms, as this technique allows different stem line aberrations and clonal developments to be distinguished. This study was designed to analyze how far groups defined according to common cytogenetic features correlated with their position in either the Kiel (KC) or the REAL classification. Cytogenetic analyses were performed on material from 175 patients with lymphoid neoplasms (LN). Samples were prepared from peripheral blood and bone marrow in acute lymphoblastic leukemia (ALL), from bone marrow in multiple myeloma (MM), and from lymph node biopsies in lymphomas. The results of this study support the inclusion of ALL, MM, and extranodal lymphomas into a comprehensive classification, because their chromosomal aberrations were always characteristic for LN. From the cytogenetic point of view, a subgroup of ALL appears as a leukemic manifestation of lymphoblastic lymphoma. MM have structural aberrations of chromosomes 1, 11, and 14 and secondary aberrations of chromosomes 3, 6, 7, 12, 13, and 18, all of which are characteristic for lymphatic disease. The groups with follicle center cell lymphoma and mantle cell lymphoma correlate well with our results both in the low-grade subtype and in the blastic variant type, the majority of cases demonstrating t(14; 18) and its variants and t(11; 14), respectively. In contrast, the group of diffuse large B-cell (DLB) lymphomas proved to be heterogeneous on the basis of our cytogenetic results. Accordingly, we would suggest keeping the immunoblastic lymphoma (IB) subtype defined by the KC. IB demonstrates no stem line aberration in common with any other group and seems to be characterized by stem line aberrations involving chromosomes 3 and 6. As some DLB lymphomas have a t(14;18) or variant translocations involving chromosome 18, they should either be separated as a subgroup or included into the group of follicle center lymphomas.

Adult↗

PubMed1996

Cervical spine motion with direct laryngoscopy and orotracheal intubation. An in vivo cinefluoroscopic study of subjects without cervical abnormality.

BACKGROUND: Cervical spine kinetics during airway manipulation are poorly understood. This study was undertaken to quantify the extent and distribution of segmental cervical motion produced by direct laryngoscopy and orotracheal intubation in human subjects without cervical abnormality. METHODS: Ten patients without clinical or radiographic evidence of cervical spine abnormality underwent laryngoscopy using a #3 Macintosh blade while under general anesthesia and neuromuscular blockade. Cervical motion was recorded with continuous lateral fluoroscopy. The intubation sequence was divided into distinct stages and the corresponding fluoroscopic images were digitized. Segmental motion, occiput through C5, was calculated for each stage using the digitized data. RESULTS: During exposure and laryngoscope blade insertion, minimal displacement of the skull base and rostral cervical vertebral bodies was observed. Visualization of the larynx created superior rotation of the occiput and C1 in the sagittal plane, and mild inferior rotation of C3-C5. C2 maintained nearneutral posture. This pattern of displacement resulted in extension at each motion segment, with the most significant motion produced at the occipitoatlantal and atlantoaxial joints (mean = 6.8 degrees and 4.7 degrees, respectively). Intubation created slight additional superior rotation at the occiput and C1, without substantial alteration in the posture of C2-C5. After laryngoscope removal, position trended toward baseline at all levels, although exact neutral posture was not regained. CONCLUSIONS: This investigation quantifies the behavior of the normal cervical spine during direct laryngoscopy with a Macintosh blade. With this maneuver, the vast majority of cervical motion is produced at the occipitoatlantal and atlantoaxial joints. The subaxial cervical segments (C2-C5) are displaced only minimally. This study establishes a highly reliable and reproducible method for analyzing cervical motion in real time.

Adult↗

PubMed1995

Glycine receptor antagonism. Effects of ACEA-1021 on the minimum alveolar concentration for halothane in the rat.

BACKGROUND: Glycine and glutamate binding sites are allosterically coupled at the N-methyl-D-aspartate (NMDA) receptor complex. Previous studies have shown that antagonism of glutamate at the NMDA receptor reduces the minimum alveolar concentration (MAC) for volatile anesthetics. 5-Nitro-6,7-dichloro-2,3-quinoxalinedione (ACEA-1021) is a competitive antagonist at the glycine recognition site of the NMDA receptor. The purpose of this study was to determine whether glycine receptor antagonism also reduces volatile anesthetic requirements in the rat. METHODS: In experiment 1, Sprague-Dawley rats were anesthetized with halothane in 50% O2-balance N2 and their lungs mechanically ventilated. They were randomly assigned to one of three groups according to the dose of ACEA-1021 administered (0, 20, or 40 mg/kg intravenously; n = 6). The bolus dose of ACEA-1021 was followed by a continuous intravenous infusion of vehicle or ACEA-1021 at 14 mg.kg-1.h-1. Halothane MAC was then determined by the tail-clamp method. In experiment 2, awake rats were randomly assigned to groups according to the same dosages of ACEA-1021 as in experiment 1. Arterial CO2 tension and mean arterial pressure were recorded before and 5 and 30 min after the start of the infusion. The infusion was then stopped, and the time to recovery of the righting reflex was recorded. RESULTS: In experiment 1, ACEA-1021 decreased halothane MAC (mean +/- SD) in a dose-dependent manner (control, 0.95 +/- 0.15 vol%; ACEA-1021 20 mg/kg, 0.50 +/- 0.14 vol%; ACEA-1021 40 mg/kg, 0.14 +/- 0.16 vol%; P < 0.01). In experiment 2, arterial CO2 tension was increased by ACEA-1021 (control, 38 +/- 3 mmHg; ACEA-1021 20 mg/kg, 43 +/- 3 mmHg; ACEA-1021 40 mg/kg, 48 +/- 2 mmHg; P < 0.01). Mean arterial pressure was not affected by any dose of ACEA-1021. The righting reflex was abolished in rats receiving ACEA-1021 40 mg/kg only and recovered 30 +/- 7 min after discontinuation of the infusion. CONCLUSIONS: Halothane MAC reduction by glycine receptor antagonism was greater than that previously observed for antagonism of glutamate at the NMDA or AMPA receptor. In rats receiving ACEA-1021 only, minimal hemodynamic depression and moderate hypoventilation were observed. Antagonism of glycine at the NMDA receptor recognition site offers a potential mechanism of action of anesthesia.

Animals↗

PubMed1994

Hypertonic saline prehydration in patients undergoing transurethral resection of the prostate under spinal anaesthesia.

Thirty-three patients undergoing elective transurethral resection of the prostate were allocated randomly to receive either 0.9% isotonic saline 7 ml kg-1 (16 patients), or 3% hypertonic saline 7 ml kg-1 (17 patients) as a preload before spinal anaesthesia. After spinal anaesthesia, the incidence of systolic arterial pressure < 75% of control value was greater in the normal saline group than in the hypertonic saline group. Also, the mean dose of phenylephrine required to maintain arterial pressure > 75% of the baseline value was significantly greater in the normal saline group than in the hypertonic saline group.

Adult↗

PubMed1994

Bovine spongiform encephalopathy surveillance in Argentina.

Bovine spongiform encephalopathy (BSE) is a new disease of cattle first described in the United Kingdom in November 1986. BSE belongs to the scrapie-related group of diseases. The epidemiological studies performed in the United Kingdom demonstrate that the BSE epidemic was caused by feeding cattle with ruminant-derived protein contaminated by a scrapie-like agent. Until June 1994, the disease had been detected in indigenous cattle in Ireland, Switzerland and France. Three cases reported in Germany, two in the Sultanate of Oman, and single cases in the Falkland Islands (Islas Malvinas), Denmark, Portugal and Canada occurred in animals imported from the United Kingdom. Several countries have implemented surveillance programmes analysing the risk factors involved in the epidemic. An analysis of risk factors conducted in Argentina shows that it is highly unlikely that BSE or scrapie exist in the country, or will arise via feed in the future. As a continuation of the analysis of risk factors, a surveillance programme was implemented in the field and in abattoirs. Specialised personnel were trained in the clinical, histopathological and biochemical detection of the disease through a network of laboratories which covered 85% of the total cattle population and 100% of the high-risk group (dairy cows over five years of age). By using a statistical procedure with reference to the bovine population in nine provinces, 1,019 brains from animals belonging to the high-risk group were selected and studied by histopathological and biochemical analyses for BSE detection. The results were negative in all cases. It can be concluded from this analysis (with a sensitivity of detection of 2.95 per 1,000, and 95% statistical confidence) that Argentina may be regarded as BSE-free, and that the importation of infected animals or by-products may represent the sole potential source of introduction of BSE infection into the country in the future.

Abattoirs↗

PubMed1994

[A case of popliteal pterygium syndrome. Considerations of timing and method of therapy].

A case of popliteal pterygium syndrome is presented and the various possibilities of treatment so far reported in the literature are discussed. The medical history of the 22-year-old male patient shows that there is no uniform concept in its therapy and that even multiple operations, which dealt only with the skin contracture and the shortened achilles tendon, were not successful. An extensive neurolysis of the sciatic nerve, its transposition into deeper muscle layers and slow extension of the knee joint with a dynamic splint did improve the patient's condition and this seems to be the concept to follow even in patients with multiple previous operations. For children with popliteal pterygium syndrome, an evaluation of the severity of contracture in degrees would be useful and a conservative treatment with splints should be begun within the first months after birth. In case of no response to conservative therapy, an operation becomes necessary. Surgery consists of the transposition of the sciatic nerve into deeper layers with simultaneous excision of fibrotic tissue, flap transfer or Z-plasty and postoperative extension of soft tissue in the knee by splinting and physiotherapy.

Abnormalities, Multiple↗

PubMed1993

A comparison of epidural tramadol and epidural morphine for postoperative analgesia.

The present study compared epidural tramadol with epidural morphine for postoperative analgesia in 20 patients undergoing major abdominal surgery. Intraoperatively, the patients were anaesthetized by a balanced technique of general anaesthesia combined with lumbar epidural lidocaine. In ten of the patients 100 mg tramadol diluted in 10 ml normal saline was also injected epidurally, while 4 mg epidural morphine was used in the other ten patients. In all patients, the visual analogue pain score, PaO2, PaCO2 and respiratory rate were monitored every hour for the first 24 hr postoperatively. In both the tramadol and morphine groups, the mean hourly pain scores ranged from 0.2 +/- 0.6 to 1.4 +/- 2.5 throughout the period of observations. However, the mean PaO2 was decreased postoperatively in the epidural morphine group, while no change was observed in the epidural tramadol group. The maximal decrease of PaO2 in the epidural morphine group was observed at the tenth hour postoperatively, when it decreased to 72.8 +/- 10.3 mmHg. This was not associated with any increase in PaCO2 or a decrease of respiratory rate, suggesting that hypoxaemia rather than hypercarbia or decreased respiratory rate may be an earlier indicator of respiratory rate, suggesting that hypoxaemia rather than hypercarbia or decreased respiratory rate may be an earlier indicator of respiratory depression in patients breathing room air without oxygen supplementation. The absence of clinically relevant respiratory depression following epidural tramadol compared with epidural morphine may be attributed to the different mechanisms of their analgesic action. The results suggest that epidural tramadol can be used to provide prolonged postoperative analgesia without serious side effects.

Abdomen↗

PubMed1993

Preliminary evaluation of a simple method for detection of bovine tuberculosis: the glutaraldehyde test.

The glutaraldehyde test (GT) is performed by mixing whole blood with a 1.25% glutaraldehyde solution. Gelification time is shorter in tuberculous cattle. This test was performed in blood samples obtained from: (a) 48 cattle with bacteriologically confirmed tuberculous lesions; (b) 61 animals with no evidence of tuberculosis at the time of slaughterhouse inspection, 14 of which had hydatid cysts; (c) 260 tuberculin-negative apparently healthy animals, and (d) 21 cattle, also tuberculin-negative but serologically positive for brucellosis. Sensitivity for detecting tuberculosis was 85.4% (41 of 48 animals). The test was negative in 298 out of 307 healthy animals (97.1% specificity). This specificity decreased when the test was applied in animals with evidence of diseases other than tuberculosis. This simple, rapid and inexpensive method could play a complementary role to the tuberculin test for detecting tuberculous cattle, especially in endemic areas with scarce resources and facilities.

Animals↗