Biomedical subjects

A Oliven

Publications and source records attributed to A Oliven.

At least 19 recordsLinked to original sources

PubMed2006

Effect of positional changes of anatomic structures on upper airway dilating muscle shortening during electro- and chemostimulation.

Positional changes of anatomic structures surrounding the upper airway are known to affect pharyngeal mechanics and collapsibility. We hypothesized that these alterations also affect the ability of the upper airway dilator muscles to enlarge the pharynx by altering their ability to shorten when activated. Using sonomicrometry, we evaluated in seven anesthetized dogs the effects of changes in tracheal and head position on the length of the genioglossus (GG) and the geniohyoid (GH) and the effects of these positional changes on the magnitude of shortening of the two muscles in response to electro- (ES) and chemostimulation (CS). Caudal traction of the trachea lengthened the GG and GH in all dogs, whereas cranial displacement of the trachea and flexion of the head to a vertical position shortened the muscles. Compared with the magnitude of ES-induced shortening in the neutral position, ES-induced shortening of the GG was 144.7 +/- 14.6, 49.3 +/- 4.3, and 33.5 +/- 11.6% during caudal and cranial displacement of the trachea and during head flexion, respectively. Similar effects of the positional changes were found for the GH, as well as for both muscles during respiratory stimulation with P(CO2) of 90 Torr at the end of CO(2) rebreathing, although inspiratory muscle shortening during CS reached only one-quarter to one-third of the magnitude observed during ES. We conclude that positional alterations of anatomic structures in the neck have a dramatic effect on the magnitude of shortening of the activated GG and GH, which may reduce substantially their ability to protect pharyngeal patency.

Adaptation, Physiological↗

PubMed2005

Correlation between levels of tumour necrosis factor-alpha and levels of pH, glucose, and lactate dehydrogenase in parapneumonic effusions.

OBJECTIVES: This study was undertaken to investigate the correlation, which has not been previously investigated, between levels of tumour necrosis factor-alpha (TNF) and levels of pH, glucose, and lactate dehydrogenase (LDH) in pleural fluid of patients with uncomplicated parapneumonic effusion (UCPPE), and patients with complicated parapneumonic effusion (CPPE). METHODS: Using a commercially-available high sensitivity ELISA kit, levels of TNF were measured in pleural fluid of patients with UCPPE (n = 23), and CPPE (n = 15), and were compared with levels of pH, glucose, and LDH in these two groups. RESULTS: The mean +/- SD values of pleural fluid TNF, pH, glucose, and LDH in the UCPPE group were 11.05 +/- 7.65 pg/ml, 7.41 +/- 0.08, 125 +/- 48 mg/dl, and 306 +/- 182 IU/l, respectively. In the CPPE group the values were 56.07 +/- 28.5 pg/ml, 6.82 +/- 0.25, 42 +/- 36 mg/dl, and 2096 +/- 1916 IU/l, respectively. The only significant correlation, which was negative, was found between levels of TNF and pH in the CPPE group (r = -0.62, P = 0.01). Levels of pleural fluid TNF and LDH were significantly higher, and levels of glucose were significantly lower in the CPPE group than in the UCPPE group (P < 0.0001). CONCLUSIONS: This study demonstrates, for the first time that TNF levels correlate inversely with levels of pH in pleural fluid of patients with CPPE but not of patients with UCPPE. This correlation may, in part, explain the pathophysiology of the pleural complications which occur in the presence of CPPE.

Adult↗

PubMed2004

Serum levels of tumor necrosis factor-alpha correlate with severity of hepatic encephalopathy due to chronic liver failure.

BACKGROUND: Several studies have shown that serum levels of tumor necrosis factor-alpha (TNF) are significantly elevated in patients with acute and chronic liver diseases, where these elevations are independent of the etiology of the underlying disease. Serum levels of TNF are significantly higher in patients with cirrhosis than in those without cirrhosis, reaching the highest levels in decompensated cirrhosis. It has also been shown that plasma levels of TNF correlate with the severity of hepatic encephalopathy (HE) in fulminant hepatic failure. However, still there are no published data regarding the relationship between blood levels of TNF and the presence or severity of HE in patients with chronic liver failure. AIM: The aim of this study is to determine the relationship between serum levels of TNF and clinical grades of HE in patients with liver cirrhosis. METHODS: Using a commercially available high-sensitivity enzyme-linked immunosorbent assay kit, serum levels of TNF were measured in 74 patients with liver cirrhosis in various clinical grades of HE (grades 0-4). RESULTS: The mean+/-SEM values of serum levels of TNF at presentation in patients with grade 0 of HE (n=23), grade 1 (n=12), grade 2 (n=14), grade 3 (n=16), and grade 4 (n=9) were 4.50+/-0.46, 9.10+/-1.0, 12.98+/-1.22, 21.51+/-2.63, and 58.26+/-19.7 pg/ml, respectively. A significant positive correlation was found between serum levels of TNF and the severity of HE (P<0.0001). CONCLUSION: Serum levels of TNF correlate positively with the severity of HE in patients with chronic liver failure.

Aged↗

PubMed2002

Correlation between polymorphonuclear leukocyte counts and levels of tumor necrosis factor-a in pleural fluid of patients with parapneumonic effusion.

High concentrations of tumor necrosis factor-a (TNF), as well as excess of polymorphonuclear leukocytes (PMNs), are present in pleural fluid of patients with complicated parapneumonic effusion (CPPE). Several studies have shown that PMNs are capable of secreting TNF. However, the correlation between levels of TNF and PMN counts in pleural fluid of patients with parapneumonic effusion has not been previously evaluated. This study was undertaken to evaluate this correlation. Using a commercially available high sensitivity ELISA kit, levels of TNF were measured in pleural fluid of patients with UCPPE (n = 22), and CPPE (n = 14), and were compared with PMN count in pleural fluid of these patients. The mean +/- SD values of pleural fluid TNF and PMN count in the UCPPE group the group were 10.15 +/- 6.48 pg/mL and 3,452 +/- 2,878 cells/mm3, respectively, and in the CPPE group the values were 55.51 +/- 29.49 pg/mL and 25,261 +/- 11,733 cells/mm3, respectively. Levels of pleural fluid TNF and PMN counts in the CPPE group were significantly higher than in the UCPPE group (p <0.0001). A significant correlation was found between levels of pleural fluid TNF and PMN counts in the CPPE group (r = 0.57, p = 0.03) and also in the UCPPE group (r = 0.44, p = 0.04). The results of this study indicate that in pleural fluid of patients with UCPPE or CPPE, levels of TNF correlate positively with PMN counts, and PMNs might be an important source of TNF production in pleural fluid of these patients, particularly in those with CPPE.

Adult↗

PubMed2002

Cutaneous leucocytoclastic vasculitis associated with omeprazole.

Omeprazole is a potent proton pump inhibitor and usually is well tolerated. Adverse effects of this drug have been reported in up to 5% of patients, most of which are trivial and disappear rapidly on discontinuation of the drug. Skin adverse reactions attributed to omeprazole are uncommon and include rashes, urticaria, angio-oedema, acute disseminated epidermal necrolysis, lichen spinulosus, and contact dermatitis. Cutaneous leucocytoclastic vasculitis (CLV) has not been previously reported in association with omeprazole. The development of CLV in an elderly patient four weeks after starting treatment with omeprazole is described.

Aged↗

PubMed2002

Prevention of prescription errors by computerized, on-line, individual patient related surveillance of drug order entry.

Computerized prescription of drugs is expected to reduce the number of many preventable drug ordering errors. In the present study we evaluated the usefullness of a computerized drug order entry (CDOE) system in reducing prescription errors. A department of internal medicine using a comprehensive CDOE, which included also patient-related drug-laboratory, drug-disease and drug-allergy on-line surveillance was compared to a similar department in which drug orders were handwritten. CDOE reduced prescription errors to 25-35%. The causes of errors remained similar, and most errors, on both departments, were associated with abnormal renal function and electrolyte balance. Residual errors remaining on the CDOE-using department were due to handwriting on the typed order, failure to feed patients' diseases, and system failures. The use of CDOE was associated with a significant reduction in mean hospital stay and in the number of changes performed in the prescription. The findings of this study both quantity the impact of comprehensive CDOE on prescription errors and delineate the causes for remaining errors.

Drug Prescriptions↗

PubMed2001

Plasmapheresis in a very young infant with atypical hemolytic uremic syndrome.

Atypical hemolytic uremic syndrome (HUS) is a heterogeneous group of disorders, the pathogenesis of which is unclear. Plasma transfusions and plasmapheresis are widely used modes of therapy for adults with this life-threatening syndrome. There is very limited experience in using plasmapheresis therapy in children and infants with atypical HUS. Plasmapheresis, which is considered a relatively safe procedure in adults and older children, may be hazardous in neonates and very young infants and can result in severe complications. We report a 2-month-old infant with idiopathic atypical HUS, who was successfully treated with a 1-month course of plasmapheresis during the acute phase of the disease. Appropriate preparations as well as several adjustments were made in order to meet the special needs of this very young infant who, to the best of our knowledge, is the youngest reported patient with atypical HUS to undergo plasmapheresis. Plasmapheresis therapy of the infant was not associated with any complications of the procedure and resulted in marked clinical improvement. We conclude that plasmapheresis in neonates and in very small infants is technically feasible, can be performed without major complications, and may be of benefit in individual cases.

Feasibility Studies↗

PubMed2001

Sublingual electrical stimulation of the tongue during wakefulness and sleep.

Pharyngeal obstruction in patients with obstructive sleep apnea (OSA) is thought to result from decreased upper airway muscle tone during sleep. The goal of the present study was to estimate the role of the tongue muscles in maintaining pharyngeal patency during sleep. Using non-invasive, sub-lingual surface electrical stimulation (ES), we measured tongue protrusion force during wakefulness and upper airway resistance during sleep in seven healthy subjects and six patients with OSA. During wakefulness, ES produced similar protrusion forces in healthy subjects and patients with OSA. ES of the anterior sublingual surface, causing preferential contraction of the genioglossus, resulted in smaller effects than combined ES of the anterior and lateral surface, which also stimulated tongue retractors. During sleep, trans-pharyngeal resistance decreased and peak inspiratory flow rate increased from 319+/-24 to 459+/-27 and from 58+/-16 to 270+/-35 ml/sec for healthy subjects and OSA patients, respectively (P<0.001). However, ES was usually unsuccessful in reopening the upper airway in the presence of complete apneas. We conclude that non-invasive ES of the tongue improves flow dynamics during sleep. Combined activation of tongue protrusors and retractors may have a beneficial mechanical effect. The magnitude of responses observed suggests that in addition to the stimulated muscles, other muscles and/or forces have a substantial impact on pharyngeal patency.

Adult↗

PubMed2001

Age-related changes in upper airway muscles morphological and oxidative properties.

Obstructive sleep apnea (OSA) is a common disorder of the middle aged and elderly. It results from the decrease in upper airway muscle (UAM) tone that occurs during sleep. It is unclear whether age-related changes in UAM could constitute a contributory mechanism to the increased prevalence of OSA with increasing age, and previous papers evaluating the effects of aging on UAM in rats reported conflicting results. In the present study, we compared, in four age groups of Wistar rats (6-24 months), fiber-type distribution, mean cross-sectional fiber area and succinate dehydrogenase optical density of dilating and non-dilating UAM, and the diaphragm. Succinate dehydrogenase optical density, a marker of oxidative capacity, decreased significantly after the age of 6 months in all muscles (except for the sternohyoid), particularly in the genioglossus, the main tongue protrudor. In this muscle, we also found a significant decrease in type IIa and an increase in IIb fibers after the age of 18 months. Age-related changes in fiber-type distribution in other muscles were mostly insignificant. Dilating UAM could not be distinguished from their non-dilating neighboring muscles by their histochemical properties or aging-related changes. The aging-related changes observed in the present study may decrease UAM endurance, particularly that of the main tongue protrudor, the genioglossus.

Aging↗

PubMed2001

Hepatotoxicity related to sucralfate.

Sucralfate is a well-established drug in the therapy of gastric and duodenal ulcers. Its adverse reactions are rare, where constipation is the most common side effect. Liver injury due to sucralfate has not been previously reported. We describe an elderly patient with significant liver injury accompanied with pruritus during treatment with sucralfate.

Journal Article↗

PubMed2001

Cells from chronic myelogenous leukaemia patients at presentation exhibit multidrug resistance not mediated by either MDR1 or MRP1.

Tetramethylrosamine (TMR) is excluded from P-glycoprotein (MDR1)-enriched cell lines, but it stains efficiently MDR1-poor parent lines. Application of the TMR resistance assay to cells obtained from chronic myelogenous leukaemia (CML) patients revealed, in all individuals, a significant resistance compared with healthy donors (P < 0.001). Cells from the same patients at later phases exhibited a further increase in TMR resistance. Doxorubicin was excluded from all cell samples obtained from CML patients at presentation. The resistance to TMR and doxorubicin was energy-dependent, and was not modulated by inhibitors of MDR1 and multidrug-resistance protein-1 (MRP1). Transcription of mRNAs suspected as relevant to multidrug resistance was assessed using comparative reverse transcription polymerase chain reaction. All cells from the CML patients transcribed high levels of MRP3, MRP4 and MRP5 compared with healthy donors. Low levels of MDR1, MRP1, MRP2, MRP6, lung resistance-related protein and anthracycline resistance-associated protein were equally transcribed in cells from healthy donors and CML patients. These results indicated that neither MDR1 nor MRP1 mediate the resistance in these cells. Our results shed light on a resistance mechanism operative in CML patients, which, together with the resistance to apoptosis, is responsible for the lack of response of CML patients to induction-type protocols used to treat acute myeloid leukaemia patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

Extracorporeal photopheresis: a review.

Extracorporeal phototherapy (ECP) is a therapeutic approach based on the biological effect of psoralen 8-methoxypsoralen (8-MOP) and ultraviolet light A (UVA) on mononuclear cells collected by apheresis, and reinfused into the patient. Photopheresis is widely used for the treatment of patients with advanced cutaneous T-cell lymphoma (CTLC). Evidence suggests that it prolongs life, and also induces 50-75% response rates. In addition, more and more reports indicate that photopheresis is a potent agent in the therapy of acute allograft rejection among cardiac, lung and renal transplant recipients. There are increasing amounts of data showing that patients with chronic graft versus host disease benefit from this therapy. Likewise, there are indications that there may be a potential role for ECP in the therapy of certain autoimmune diseases resistant to conventional therapy. The mechanism of this treatment is likely due to the induction of anticlonotypic immunity directed against pathogenic clones of T lymphocytes. Treatment induces apoptotic death of pathogenic T-cells, and it is postulated that activation of antigen-presenting cells has important effects in this process.

Animals↗

PubMed2001

Macular infarction in thrombotic thrombocytopenic purpura.

PURPOSE: To report a patient with transient acute generalized thrombotic thrombocytopenic purpura (TTP) who suffered severe permanent visual loss due to retinal vascular occlusions in both eyes. METHODS: Case report. RESULTS: Severe permanent visual loss occurred in a patient with acute transient TTP. Extensive soft exudates were seen at the fundus of both eyes. Fluorescein angiography demonstrated multiple retinal vascular occlusions associated with capillary nonperfusion. CONCLUSIONS: Severe and permanent visual loss due to retinal vascular occlusions demonstrated by fluorescein angiography occurred in a patient with transient thrombotic thrombocytopenic purpura.

Adult↗

PubMed2001

Severe symptomatic hyponatremia during citalopram therapy.

Hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is an uncommon complication of treatment with the new class of antidepressant agents, the selective serotonin reuptake inhibitors (SSRIs). Most of the reported cases were associated with fluoxetine; only 2 have previously been described in association with citalopram. We describe an elderly woman who presented with severe symptomatic hyponatremia caused by the SIADH during therapy with citalopram. Because the use of SSRIs is becoming more popular among elderly depressed patients, the present case and the other 2 reported previously emphasize the need for greater awareness of the development of this serious and potentially fatal complication also in association with citalopram therapy and suggest that serum sodium levels should be monitored closely in elderly patients during treatment with citalopram.

Aged↗

PubMed2001

Bowel perforation due to gastrointestinal autonomic nerve tumour associated with neurofibromatosis type 1.

Gastrointestinal autonomic nerve (GAN) tumours form a distinct subcategory of gastrointestinal stromal tumours, and are thought to originate from the enteric autonomic plexus. To date, a total of 45 cases have been documented in the literature; a few of these cases were associated with neurofibromatosis type 1 (NF-1). Bowel perforation due to other gastrointestinal stromal tumours has been reported only twice, but never in association with a GAN tumour. We describe a 40-year-old woman with NF-1 who had bowel perforation due to a GAN tumour. The patient underwent radical surgical resection and remained tumour free for at least 4 years, which may indicate a good prognosis.

Adult↗

PubMed2001

Severe hepatotoxicity with jaundice associated with paroxetine.

Hepatotoxicity due to paroxetine, a selective serotonin reuptake inhibitor, is very rare, and to the best of our knowledge, only five cases of liver injury in association with paroxetine have previously been reported in the medical literature. We describe the clinical, biochemical, and pathological findings in a patient with paroxetine hepatotoxicity, which was reversed after withdrawal of the drug. The present case and the others previously reported suggest that hepatotoxicity should be taken into account as a rare complication, sometimes severe, that may occur with paroxetine.

Chemical and Drug Induced Liver Injury↗

PubMed2001

Squamous cell carcinoma of the lung presenting with cutaneous leukocytoclastic vasculitis: a case report.

An elderly patient with paraneoplastic cutaneous leukocytoclastic vasculitis (CLV) leading to the discovery of an as-yet asymptomatic, potentially surgically curable squamous cell carcinoma of the lung is presented. This type of vasculitis has not been previously described in association with this type of lung cancer. Since vasculitic paraneoplastic syndromes, including CLV, may develop before the clinical presentation of malignant tumors, the present case and others previously reported strongly suggest that in apparently idiopathic CLV, patients should be evaluated for the presence of occult malignancy that could be curable by early detection.

Aged↗

PubMed2001

Coma and seizures due to severe hyponatremia and water intoxication in an adult with intranasal desmopressin therapy for nocturnal enuresis.

Desmopressin, a synthetic analogue of the antidiuretic hormone, is an effective medication for primary nocturnal enuresis for both children and adults. Its safety is well established. Although it has a favorable side effect profile, because of its pharmacological effect, intranasal desmopressin can rarely induce water intoxication with profound hyponatremia if given without adequate restriction of water intake. The authors describe an adult patient with water intoxication and severe hyponatremia accompanied by loss of consciousness and seizures after 2-day intranasal administration of desmopressin. The present and the previously reported cases emphasize the need for greater awareness of the development of this serious and potentiallyfatal complication. In addition, to adjust the drug to the lowest required dosage, adequate restriction of water intake is recommended, and serum levels of sodium should be measured periodically to allow for early detection of water intoxication and hyponatremia.

Administration, Intranasal↗