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Biomedical subjects

N Krivoy

Publications and source records attributed to N Krivoy.

67 records · Page 4Linked to original sources
PubMed1980

[Aortic regurgitation and aortic stenosis associated with gastrointestinal bleeding. Report of a case (author's transl)].

A 67-year-old woman with a double atherosclerotic aortic valvulopathy and rheumatoid arthritis presented recurrent episodes of gastrointestinal bleeding. Selective arteriography of the superior mesenteric artery demonstrated the existence of vascular malformations with extravasation of the contrast. The physiopathology of this lesion is unknown, but its incidence in adulthood suggests a degenerative process. A selective angiogram of the superior mesenteric artery is mandatory in patients with gastrointestinal bleeding and double aortic valvulopathy in order to establish the etiological diagnosis of the hemorrhage.

Aged↗
PubMed1980

Subacute bacterial endocarditis.

Two patients in whom various immunological phenomena obscured and delayed the diagnosis of subacute bacterial endocarditis (SBE) are described. Immunological abnormalities usually correlate well with the chronicity and severity of the disease, as is demonstrated here. The mechanisms underlying the various immunological phenomena are discussed. The importance of alertness to the possibility of SBE in cases of disease manifesting itself as an immunological disorder, thus achieving early diagnosis and early antimicrobial treatment, is stressed.

Adult↗
PubMed1980

Maintenance oral theophylline therapy: suggested schedule in elderly patients.

18 elderly patients (17 male and 1 female) with chronic obstructive pulmonary disease, and 2 elderly patients (1 male, 1 female) with an acute asthmatic attack were treated with theophylline. Receiving the same intravenous loading dose (5.6 mg/kg) and oral maintenance dosage (1,500 mg), the patients were divided into two groups (A and B) differentiated only by the time interval between oral doses (tau). Group A was treated every 8 h, and group B every 6 h. Although theophylline levels in both groups were similar during the infusion period, patients in group B fared significantly better (p less than 0.01) than patients in group A in reaching a therapeutic blood theophylline level. We conclude that an average dosage of 20 mg/kg of theophylline divided in 6-hour intervals is the more effective schedule in elderly patients without cardiac or hepatic involvement.

Administration, Oral↗
PubMedDate not supplied

Pharmacokinetic analysis of amikacin twice and single daily dosage in immunocompromised pediatric patients.

Ten children received amikacin twice daily and 13 were treated using the single daily protocol. All had fever and neutropenia on admission, and received a total daily dose of 20 mg/kg when included in the study. Individual pharmacokinetic parameters were calculated using a one-compartment model for two blood amikacin samples. The mean (+/- SD) of elimination half-life (h), amikacin clearance (l/h/kg), volume of distribution (l/kg), peak concentration (microgram/ml) and trough concentration (microgram/ml) were: 2.51 (0.74) and 2.85 (0.32) h; 0.26 (0.16) and 0.115 (0.02) l/h/kg; 0.74 (0.44) and 0.47 (0.11) l/kg; 19.1 (12.3) and 42.6 (12.6) micrograms/ml; 0.85 (0.74) and 0.18 (0.24) microgram/ml with twice and single daily dosage schedules, respectively. A single daily dose of amikacin had a significantly longer elimination half-life, lower clearance, higher peak concentration and lower trough concentration in comparison to the twice-daily schedule. The use of amikacin 20 mg/kg daily delivered in a single daily dose is recommended for immunocompromised pediatric patients with fever and neutropenia, in spite of the measured pharmacokinetic differences.

Adolescent↗
PubMedDate not supplied

Maternal and fetal digoxin-like immunoreactive factor in elective cesarean sections and spontaneous vaginal delivery.

The effect of mode of delivery on maternal and newborn plasma levels of total digoxin-like immunoreactive factor was evaluated. 32 healthy at term parturients with normal fetuses were studied. The cord blood level of digoxin-like immunoreactive factor of the 16 vaginally delivered infants was significantly higher than in the 16 matched controlled newborns delivered by an elective Cesarean section (1381 +/- 334 versus 1104 +/- 338 pg/ml, p less than 0.02). No differences were found between the maternal venous blood levels of digoxin-like immunoreactive factor of both study groups. The cord blood levels of this factor in the vaginal as well as the Cesarean section groups were significantly higher than the concentration in the corresponding maternal blood (p less than 0.001 and p less than 0.01, respectively). It is suggested that the changes in digoxin-like immunoreactive factor in the cord blood may reflect the stress of vaginal delivery on the fetus.

Adult↗
PubMedDate not supplied

Therapeutic monitoring of busulfan in pediatric bone marrow transplantation.

The aim of this study was to describe busulfan disposition in a pediatric population who underwent bone marrow transplantation (BMT). Busulfan administered dose was 1 mg/kg every 6 h for 4 days. Plasma determinations were performed after the first dosing at 0, 15, 30, 60, 90, 120, 180, 240, 300, and 360 min. A noncompartment analysis model for extravascular absorption was used for the pharmacokinetic analysis. To obtain the area under the concentration-time curve (AUC) within the "therapeutic window" of 1,000-1,200 microM x minutes a busulfan dose adjustment Was performed at the fourth dose. Forty-five busulfan pharmacokinetic analyses were performed in 34 children. Eleven children had their dose adjusted [1.19 +/- 0.14) mg/kg] at the fourth dose and the AUC was monitored at the fifth one. The mean AUC +/- SD after the fifth dose (998.1 +/- 189.2 microM x min) was different (p = .006)from that after the first dose (1 mg/kg) (687.63 +/- 166.43 microM x min). Six children had their first AUC into the "therapeutic window," 17 children had their dose adjusted [1.2 (+/- 0.22) mg/kg], but the "adjusted" AUC was not available. These data suggest that it may be reasonable to recommend a busulfan dose of 1.2 mg/kg to achieve the accepted therapeutic target in children undergoing BMT.

Animals↗
PubMedDate not supplied

Pharmacokinetic analysis of gentamicin thrice and single daily dosage in pediatric cancer patients.

Fifty-two children suffering from different types of malignancies were included and evaluated for the pharmacokinetics of gentamicin thrice or single daily dosage protocols. All the study population received a total dose of 5 mg/kg daily. Thirty children received gentamicin thrice daily, and 22 were treated using the single daily protocol; all had fever and neutropenia when included. The individual pharmacokinetic parameters were calculated using a one-compartment model for two blood gentamicin samples. The mean (SD) t 1/2 (h), clearance (mL/min/BSA), Vss (L/kg), Cmax (micrograms/mL), and Cmin (micrograms/mL) were 3.05 (1.0) and 3.9 (0.6) h, 136 (61.3) and 99.9 (65.3) mL/min/BSA, 0.4035 (0.167) and 0.457 (0.17) L/kg, 5.2 (2.0) and 11.5 (4.2) micrograms/mL, 0.8 (0.6) and 0.18 (0.1) microgram/mL for thrice and single daily dosage schedules, respectively. The single gentamicin daily dose protocol had a significantly longer t 1/2, shorter clearance normalized to BSA, higher Cmax, and lower Cmin in comparison with the thrice daily schedule. We recommend the use of gentamicin at 5 mg/kg daily delivered as a single daily dose for pediatric cancer patients with fever and neutropenia, in spite of the measured pharmacokinetic differences, which in our opinion have no clinical significance.

Adolescent↗
PubMedDate not supplied

Pharmacokinetic analysis of vancomycin in steady state in pediatric cancer patients.

Thirty children suffering from different types of malignancies, neutropenic fever, and suspected staphylococcal bacteremia were evaluated for the pharmacokinetics of vancomycin in steady-state conditions and compared with eight children suffering from proven methicillin-resistant staphylococcal infection. All the studied population received intravenous vancomycin at 40 mg/kg daily divided into four daily doses. The individual pharmacokinetic parameters were calculated using a one-compartment model for two blood vancomycin samples. The mean (+/- SD) half-time (t1/2, hours), clearance (L/h/kg), Vss (L/kg), Cmax (microgram/mL), and Cmin (microgram/mL) were 10.5 (7.9) and 14.9 (9.1) hours; 0.11 (0.14) and 0.06 (0.06) L/h/kg; 0.62 (0.33) and 1.3 (0.6) L/kg; 28.3 (11.8) and 22.3 (9.8) micrograms/mL; and 5.7 (6.0) and 7.4 (4.8) micrograms/mL for the malignancy and control groups, respectively. The malignancy group had a significantly shorter t1/2 (P = .005), higher clearance (P = .005), and lower Cmin (P = .03) in comparison with the control group. It is suggested that the prescription of vancomycin at 40 mg/kg daily, divided into four daily doses, is safe and will provide a peak blood level of vancomycin sufficient to cover the broad spectrum of staphylococcal bacteria. The vancomycin dose should be individualized, based on an individual pharmacokinetic profile.

Anti-Bacterial Agents↗