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Biomedical subjects

M Elisaf

Publications and source records attributed to M Elisaf.

At least 19 recordsLinked to original sources
PubMed2000

A new method for determination of serum cholestanol by high-performance liquid chromatography with ultraviolet detection.

We developed a method for the determination of serum 5alpha-cholestan-3beta-ol (cholestanol). The sterols were derivatized to the 4'-bromobenzenesulfonyl esters and heated in isopropanol. The cholesterol-4'-bromobenzenesulfonate was solvolyzed to cholesteryl isopropyl ether, but the derivatized cholestanol did not change and could be measured in a high-performance liquid chromatographic system equipped with a UV detector at 235 nm. On the other hand, the resulting cholesteryl isopropyl ether, having different absorbance and chromatographic mobility was not detected. This method was used for measuring cholestanol levels in patients with cerebrotendinous xanthomatosis (CTX), liver cirrhosis and serum from healthy control subjects. Reproducibility, linearity and recovery tests were done on 0.3 ml of serum samples containing >2 microg/ml cholestanol, using stigmastanol as an internal standard (I.S.). Determining cholestenol by this method can be used for diagnosis and follow-up of patients with CTX and various liver diseases.

Adult↗
PubMed2000

Syndrome of inappropriate antidiuresis associated with multiple sclerosis.

Even though many disorders of the nervous system have been reported to be associated with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), the association of this syndrome with multiple sclerosis is extremely rare. We describe a patient with multiple sclerosis who developed SIADH and hyponatremia.

Humans↗
PubMed2000

Potential aetiological factors concerning the development of osteonecrosis of the femoral head.

BACKGROUND: The aetiology and pathogenesis of non-traumatic osteonecrosis (ON) of the femoral head have not been fully elucidated. The present study was conducted to evaluate the possible correlation of relevant haematological and biochemical factors with the development of ON. PATIENTS AND METHODS: Our investigation consisted of measurement of haematological indices and assessment of the biochemical and lipid profile of a study population of 68 patients with non-traumatic ON of the femoral head and 36 healthy controls. The disease was considered idiopathic in 17 and secondary in 51 patients. RESULTS: There were no statistically significant differences in the parameters measured among the idiopathic ON, secondary ON and control groups, except for globulins alpha1, alpha2 and beta, which were significantly increased in both patient groups, and apolipoprotein B (Apo B), which was increased in patients with idiopathic disease compared with the control group. Both patient groups presented increased von Willebrand factor (VWF) and lipoprotein (a) [Lp(a)] levels and decreased protein C and S concentrations, but without statistical significance. However, both patient groups exhibited a greater proportion of abnormal values of any of these parameters, in 58.9% of the idiopathic and in 62.7% of the secondary ON patients, compared with 8.3% of the controls. CONCLUSION: Our study underlines the potential association of abnormal values of protein C, protein S, VWF and Lp(a) with ON. To our knowledge this is the first reported association of VWF with the disease. The majority of both idiopathic and secondary ON patients in our series exhibits a thrombotic potential that adds further support to the postulation that intravascular coagulation is a major pathogenetic mechanism leading to the disease.

Adult↗
PubMed2000

Extensive lymphadenopathy as the first clinical manifestation in systemic lupus erythematosus.

Lymphadenopathy (LAP) is a frequent sign of systemic lupus erythematosus (SLE). The lymph nodes are usually soft, nontender, varying in size from 0.5 cm to several centimeters. However, generalized LAP in SLE is extremely rare, while to our knowledge, the presentation of extensive LAP with blocks of retrosternal, mesenteric, and retroperitoneal nodes has not been previously reported as the first clinical manifestation of the disease. In this report we describe a patient with extensive LAP and active SLE and we point out that generalized LAP should be included among the clinical findings indicating disease activity in SLE patients.

Adult↗
PubMed1999

Association of the inflammatory state in active juvenile rheumatoid arthritis with hypo-high-density lipoproteinemia and reduced lipoprotein-associated platelet-activating factor acetylhydrolase activity.

OBJECTIVE: To investigate the relationship between the quantitative and qualitative abnormalities of apolipoprotein B (Apo B)- and Apo A-I-containing lipoproteins and between lipoprotein-associated platelet-activating factor acetylhydrolase (PAF-AH) activity in patients with juvenile rheumatoid arthritis (JRA) as a function of the inflammatory state. METHODS: Twenty-six JRA patients and 22 age- and sex-matched control subjects with normal lipid levels participated in the study. Fourteen patients had active disease, and 12 had inactive disease. Plasma lipoproteins were fractionated by gradient ultracentrifugation into 9 subfractions, and their chemical composition and mass were determined. The PAF-AH activity associated with lipoprotein subfractions and the activity in plasma were also measured. RESULTS: Patients with active JRA had significantly lower plasma total cholesterol and high-density lipoprotein (HDL) cholesterol levels as compared with controls, due to the decrease in the mass of both the HDL2 and HDL3 subfractions. Patients with active JRA also had higher plasma triglyceride levels, mainly due to the higher triglyceride content of the very low-density lipoprotein plus the intermediate-density lipoprotein subfraction. The plasma PAF-AH activity in patients with active JRA was lower than that in controls, mainly due to the decrease in PAF-AH activity associated with the intermediate and dense low-density lipoprotein subclasses. The lipid abnormalities and the reduction in plasma PAF-AH activity were significantly correlated with plasma C-reactive protein levels and were not observed in patients with inactive JRA. CONCLUSION: This is the first study to show that patients with active JRA exhibit low levels of HDL2 and HDL3 and are deficient in plasma PAF-AH activity. These alterations suggest that active JRA is associated with partial loss of the antiinflammatory activity of plasma Apo B- and Apo A-I-containing lipoproteins.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1999

Platelet aggregatory response to platelet activating factor (PAF), ex vivo, and PAF-acetylhydrolase activity in patients with unstable angina: effect of c7E3 Fab (abciximab) therapy.

OBJECTIVE: Platelet activation and aggregation is a dominant feature in the pathophysiology of unstable angina. The final step of platelet aggregation is mediated through the platelet integrin glycoprotein IIb/IIIa (GP IIb/IIIa), while abciximab (ReoPro) is one of the most potent inhibitors of this receptor. Platelet-activating factor (PAF) is a potent platelet agonist which is degraded and inactivated by PAF-acetylhydrolase (PAF-AH). The plasma form of PAF-AH is associated with lipoproteins. We studied the platelet response to the aggregatory effect of PAF, ex vivo, in relation to the plasma PAF-AH activity in 32 patients with unstable angina, as well as the effect of abciximab therapy on the above parameters. METHODS: Thirty two patients with unstable angina and 25 sex- and age-matched healthy controls participated in the study. On the day of admission (day 1) 17 patients received a bolus of abciximab (0.25 mg/kg) followed by a 12-h infusion (10 micrograms/min). Platelet aggregation to both PAF and ADP, in platelet rich plasma, was successively studied in both patients receiving abciximab or remaining untreated. The plasma and HDL-associated PAF-AH activity was also determined at the same times. RESULTS: In the untreated patients, the PAF EC50 values were significantly lower on the day of admission, whereas the maximal percentage of aggregation was significantly higher compared to controls (p < 0.01 for both comparisons). Similar behaviour of the platelets was observed in the aggregatory effect of ADP. This aggregatory response was not significantly altered 4 days, 7 days or 1 month afterwards. In the 17 patients who received abciximab, platelet aggregation to both PAF and ADP was inhibited by 90 +/- 5 and 96 +/- 3%, respectively, 1 h after bolus. At 2 and 3 days after treatment, platelet aggregation to both agonists was significantly recovered being similar to controls. However, it was fully restored 6 days after bolus, still being significantly higher compared to controls (p < 0.01 for PAF and p < 0.003 for ADP). The total plasma PAF-AH activity in both patient groups was not different from that of controls, whereas the HDL-associated PAF-AH activity was significantly lower. The total plasma or HDL-associated enzyme activity was not altered at any time interval studied, and it was not influenced by abciximab. CONCLUSIONS: The increased aggregatory response of platelets to PAF and the low plasma levels of HDL-cholesterol and HDL-associated PAF-AH activity in patients with unstable angina may contribute to the severe atherosclerosis and to acute thrombosis found in these patients. Abciximab therapy may protect platelets from PAF action in vivo the first days after drug administration, but it fails to permanently restore the enhanced aggregatory response observed.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1999

Homogeneous HDL-cholesterol assay versus ultracentrifugation/dextran sulfate-Mg2+ precipitation and dextran sulfate-Mg2+ precipitation in healthy population and in hemodialysis patients.

OBJECTIVES: To evaluate the analytical performance of a new homogeneous HDL-cholesterol assay (Olympus Diagnostica). To investigate possibly discrepant results in chronic hemodialysis patients who commonly exhibit quantitative and qualitative lipoprotein abnormalities, responsible for atherogenic complications in these patients. DESIGN AND METHODS: Serum samples were collected from 50 healthy subjects and 65 chronic hemodialysis patients. HDL-C levels measured by the homogeneous assay were compared with the routine dextran sulfate-Mg2+ precipitation method and the ultracentrifugation/dextran sulfate-Mg2+ precipitation as reference method. RESULTS: The homogeneous assay was linear up to at least 220 mg/dL. The analytical precision was estimated with three different sets of commercial controls and one set of human pooled serum control. The within-day CV ranged between 1.7% and 3.8% and the between-day CV ranged between 1.0% and 2.3%. HDL-C values in both populations correlated highly with the dextran sulfate-Mg2+ precipitation method and the ultracentrifugation/dextran sulfate-Mg2+ precipitation method (r > or = 0.96, bias between -0.9 and 2.3 mg/dL). Lipemia up to triglyceride concentration of 600 mg/dL did not alter the HDL-C value. CONCLUSIONS: The homogeneous assay for HDL-C (Olympus) uses much less sample, is accurate and convenient to handle, and allows full automation. The test should considerably facilitate the screening of individuals at an increased risk of cardiovascular disease, including hemodialysis patients.

Adult↗
PubMed1999

The incidence of thyroid function abnormalities in patients attending an outpatient lipid clinic.

Thyroid disorders are known to influence lipoprotein metabolism. In the current study we examined the incidence of thyroid function abnormalities in patients attending our outpatient lipid clinic. During the last 2 years, 248 patients were admitted to our lipid clinic for the diagnosis and management of dyslipidemia. In all cases, a detailed medical history was obtained and a thorough physical examination was performed with emphasis on the presence of symptoms/signs indicative of underlying thyroid diseases. In addition to lipid parameters, thyrotropin (TSH) and free thyroxine (FT4) levels were measured in a fasting blood sample. Seven female asymptomatic patients (2.8%) had frank biochemical hypothyroidism, and 11 patients (9 female, 2 male) (4.4%) had subclinical hypothyroidism with TSH levels between 5.8-19 mU/L. After restoration of a euthyroid state with levothyroxine therapy, no significant changes in serum lipid parameters were observed in the whole group of patients with subclinical hypothyroidism. However, in 4 patients with TSH levels >12 mU/L relatively small doses of levothyroxine (75 microg/day) were followed by a significant improvement of serum lipid profile. Interestingly, 3 patients exhibited clinical or subclinical hyperthyroidism that influenced serum lipid parameters as well as the effectiveness of hypolipidemic treatment. It is concluded that thyroid function abnormalities are relatively common in dyslipidemic patients attending a lipid clinic and could significantly affect the patients' lipid profile as well as the patients' management.

Dose-Response Relationship, Drug↗
PubMed1999

Effect of micronized fenofibrate and losartan combination on uric acid metabolism in hypertensive patients with hyperuricemia.

It has been reported that micronized fenofibrate and losartan can significantly decrease serum uric acid levels by augmenting uric acid excretion. We undertook this study to evaluate the effects of the combination treatment with micronized fenofibrate and losartan in nondiabetic hypertensive dyslipidemic patients with hyperuricemia (serum uric acid, >7 mg/ dl). A total of 25 patients (15 men, 10 women) aged 21-66 years was studied. In all patients, serum lipid parameters, including Lp(a), fibrinogen, and uric acid levels, as well as fractional excretion of uric acid (FEUA) were obtained before treatment, 8 weeks after micronized fenofibrate treatment (200 mg daily), and 8 weeks after combination therapy with micronized fenofibrate (200 mg daily) and losartan (50 mg daily). Fenofibrate alone significantly decreased total cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, Apo B, Lp(a), fibrinogen, and uric acid levels (from 7.6+/-0.55 to 5.6 +/-0.5 mg/dl; p < 0.0001) and increased high-density lipoprotein (HDL) cholesterol, Apo A1, and FEUA (from 6.5+/-1.8% to 12.2+/-4%; p < 0.0001). The addition of losartan beyond the decrease in blood pressure values did not significantly alter serum metabolic parameters. However, a small additional decrease in serum uric acid levels (from 5.6+/-0.5 to 4.9+/-1 mg/dl; p < 0.05) was found because of a further increase in FEUA (from 12.2+/-4% to 14+/-5.5%; p < 0.05). It is concluded that the combination of micronized fenofibrate and losartan is useful for the management of patients with multiple metabolic abnormalities, including hyperuricemia.

Adult↗
PubMed1999

Assessment of the performances of three oscillometric blood pressure monitors for neonates using a simulator.

BACKGROUND: The majority of monitors for non-invasive measurement of blood pressure in neonates and infants use the oscillometric method. OBJECTIVE: To use a simulator to investigate the overall system accuracy for three oscillometric blood pressure monitors. The tested devices are DINAMAP 8100 (Critikon), SpaceLabs M90426 (SpaceLabs Medical)and the module HP M 1008B (Hewlett-Packard). METHODS: The blood pressure values obtained by the three devices were compared with those of the invasive reference. A blood pressure simulator was used for testing the performance of the three blood pressure monitors. RESULTS: The Dinamap and SpaceLabs readings are generally in good agreement with the invasive reference. In contrast, the HP M 1008B readings for the diastolic and mean arterial pressures are inaccurate (the mean errors are 21 and 15mmHg, respectively). CONCLUSION: These results contradict our previously published data obtained when a different simulator (Cufflink)was used. These findings are important, because blood pressure values that are too low can result in a different therapeutic approach being applied, for newborn babies have only a small range of mean arterial pressure for the autoregulation of the cerebral blood flow.

Blood Pressure↗
PubMed1999

Severe muscle weakness due to hypokalemia as a manifestation of small-cell carcinoma.

We describe the case of a 56-year-old man with severe muscle weakness due to heavy hypokalemia (serum potassium 1.44 mmol/l) associated with inappropriate kaliuria and alkalemia. Subsequent investigation revealed the presence of ectopic ACTH hypersecretion due to a small-cell lung carcinoma. A significant clinical/laboratory improvement was achieved following chemotherapy-induced regression of the primary tumor. The profound hypokalemia was probably the result of cortisol hypersecretion, which in concert with the ACTH-induced decreased 11beta-hydroxysteroid dehydrogenase activity can exhibit an increased mineralocorticoid activity. In addition, other ACTH-dependent mineralocorticoids may play a contributory role in the development of severe hypokalemia.

ACTH Syndrome, Ectopic↗