Search PubMed⌕ Search

Biomedical subjects

P Deutsch

Publications and source records attributed to P Deutsch.

At least 19 recordsLinked to original sources

The effect of MK-0524, a prostaglandin D(2) receptor antagonist, on prostaglandin D (2)-induced nasal airway obstruction in healthy volunteers.

INTRODUCTION: Nasal congestion in allergic rhinitis results from tissue edema and vasodilatation in the nasal mucosa. Of the mediators released by mast cells in response to allergens, prostaglandin (PG) D(2) is regarded as the most potent inducer of nasal congestion. Intranasal administration of PGD(2) reproduces the nasal blockade experienced by patients with seasonal allergic rhinitis (SAR) via its action on the PGD(2) (DP) receptor to induce nasal vasodilatation. Intranasal challenge with PGD(2) can be a useful tool for evaluating DP-receptor antagonists. OBJECTIVE: The main purpose of this study was to examine the ability of MK-0524, a DP receptor antagonist in development for the treatment of SAR, to block PGD(2) induced nasal congestion in healthy volunteers. METHODS: To this end, a double-blind, placebo-controlled, randomized, 3-period study was performed in 15 healthy subjects. During each period, subjects received MK-0524 25 mg, MK-0524 100 mg or placebo qd for 3 days. Twenty-four hours following the last dose, nasal provocations with PGD(2) were performed to determine the PD(75), which is the intranasal dose of PGD(2) that provokes a 75% increase in baseline total nasal airway resistance as performed by active anterior rhinomanometry. RESULTS: Following treatment with MK-0524, the PD(75) (mean+/-SD) was significantly shifted from 15.8 +/- 18.3 mug/nostril during the placebo period to more than 512 mug/nostril both following the 25- and 100-mg (maximum challenge dose tested) dose regimen. CONCLUSION: Whether this >45 fold increase in PD(75) will induce a clinically meaningful effect of MK-0524 will require clinical study in participants with SAR.

Administration, Oral↗

Single-dose pharmacokinetics and tolerability of alendronate 35- and 70-milligram tablets in children and adolescents with osteogenesis imperfecta type I.

CONTEXT: Alendronate (ALN) is a bisphosphonate compound that can be administered orally and has potential use in pediatric osteoporotic conditions. OBJECTIVE: The objective was to evaluate the pharmacokinetics and single-dose tolerability of ALN in children with osteogenesis imperfecta. DESIGN: ALN was administered iv and orally in a two-period, randomized crossover study, with doses separated by a 2-wk washout and follow-up carried out within 2 wk after the last ALN dose. SETTING: The study was conducted at the pediatric metabolic bone research unit at the Shriners Hospital for Children, Montréal, Canada. PATIENTS: Twenty-four children (aged 4-16 yr; eight girls) with osteogenesis imperfecta type I participated. INTERVENTIONS: All patients received iv ALN at a dose of 125 mug. In addition, patients weighing less than 40 kg received an oral dose of ALN 35 mg, whereas those weighing 40 kg or more received ALN 70 mg orally. MAIN OUTCOME MEASURES: Total urinary excretion and oral bioavailability of ALN, blood and urine safety parameters, and adverse events were the main outcome measures. RESULTS: The total urinary excretion of ALN after the iv dose was similar for both weight groups. The mean oral bioavailability (95% confidence interval) was 0.43% (0.28, 0.64%) for patients weighing less than 40 kg and 0.56% (0.36, 0.87%) for patients weighing 40 kg or more. Eighteen patients reported a total of 44 clinical adverse experiences, none of which were serious. The most common adverse experiences were mild to moderate headache (n = 7), nausea (n = 7), fever (n = 5), and abdominal pain (n = 6). Eighty percent of the adverse experiences (35 of 44) occurred within 48 h of medication administration, 91% (40 of 44) lasted less than 24 h, and 84% (37 of 44) were reported after oral dosing. Laboratory safety monitoring revealed a marginal decrease in absolute lymphocyte count and serum alkaline phosphatase after the study compared with baseline for both weight categories. CONCLUSIONS: The mean oral bioavailability of 35- and 70-mg ALN tablets was less than 0.6%, comparable to adult studies. Adverse experiences from single-dose ALN were minor, and the drug was generally well-tolerated.

Adolescent↗

[Action to be taken when facing one or more cases of whooping-cough].

The evolution of the epidemiology of pertussis, new licensed macrolides and vaccines, new recommendations for vaccination among adolescents and adults need an update of the French guidelines for prevention of the disease around one or grouped cases of the disease. A particular attention should be raised to the diagnosis of whooping cough in adults who are presently the main reservoir of Bordetella pertussis. Whooping cough in adults presents as an unexplained prolonged cough with nocturnal exacerbation witch accounts for most of the contaminations of young infants. A bacteriological confirmation of pertussis should be provided before implementation of preventive measures: culture and PCR are presently the gold standard for the diagnosis of pertussis in infants, children and even adults who have been coughing for less than 20 days. Later on, serology (Elisa, immuno-empreinte) is the only technique available, but cannot be interpreted if the patient has been vaccinated less than one year ago. Infants under three months should be admitted to hospital and every case submitted to respiratory isolation. Eviction from the community should be pronounced within the five first days following the onset of an effective antibiotic treatment. New macrolides should be favoured: clarithromycin for seven days or azithromycin for five days. Household contacts should be given the same prophylactic antibiotic treatment: children and adolescent not correctly immunized, parents of the index case as adults parents of not or not completely immunized infants. The vaccination program of the household should be updated. The same measures should be applied in case of grouped cases (at least two contemporary or consecutive cases in the same area). In that case, the Public Health System doctors should be involved in the investigation and the classification of the cases. The close contacts not or not completely immunized should be prescribed and antibiotic prophylaxis and an update of their vaccination program. Among the occasional contacts, high-risk people only should be treated. In the day care centres an antibiotic prophylaxis should be given to children who have received less than four vaccine shots against pertussis and to the personnel contact to the cases as well. In the schools, the antibiotic prophylaxis should be prescribed to all children of the classroom(s) not completely vaccinated and to the teacher(s) as well. In the boarding schools and institutions with handicapped children, antibiotic prophylaxis could be applied to every member if the pertussis vaccine coverage is at less than 50%. In hospitals, coughing personnel should wear masks and investigations towards pertussis should be performed in people with a more than seven day unexplained cough. Preventive measures should be applied in case of confirmation of pertussis.

Adult↗

Pharmacokinetics of total and unbound ertapenem in healthy elderly subjects.

Ertapenem is a new once-a-day parenteral carbapenem antimicrobial agent. The pharmacokinetics of unbound and total concentrations of ertapenem in plasma were investigated in elderly subjects and compared with historical data from young adults. In a single- and multiple-dose study, healthy elderly males and females (n = 14) 65 years old or older were given a 1-g intravenous (i.v.) dose once daily for 7 days. Plasma and urine samples collected for 24 h on days 1 and 7 following administration of the 1-g doses were analyzed by reversed-phase high-performance liquid chromatography. Areas under the concentration-time curve from 0 h to infinity (AUC(0- infinity )) for elderly females and males were similar following administration of 1-g single i.v. doses, and thus, the genders were pooled in subsequent analyses. Concentrations in plasma and the half-life of ertapenem were generally higher and longer, respectively, in elderly subjects than in young adults. The mean AUC(0- infinity ) of total ertapenem in the elderly was 39% higher than that in young subjects following administration of a 1-g dose. The differences were slightly greater for the mean AUC(0- infinity ) of unbound ertapenem (71%). The unbound fraction of ertapenem in elderly subjects ( approximately 5 to 11%) was generally greater than that in young adults ( approximately 5 to 8%). As in young adults, ertapenem did not accumulate upon multiple dosing in the elderly. The pharmacokinetics of ertapenem in elderly subjects, while slightly different from those in young adults, do not require a dosage adjustment for elderly patients.

Adult↗

Tissue penetration by ertapenem, a parenteral carbapenem administered once daily, in suction-induced skin blister fluid in healthy young volunteers.

The penetration of 1 g of intravenous ertapenem once daily for 3 days in suction-induced skin blisters was evaluated. Ten forearm blisters were formed (n = 12) 12 h prior to the last dose. Concentrations of ertapenem in blister fluid exceeded 4 micro g/ml (the MIC at which 90% of the isolates tested are eliminated) for the entire dosing interval. The area under the concentration-time curve for 0 to 24 h ratio of blister fluid to plasma was 61% (90% confidence interval, 56, 65%) suggesting good blister penetration.

Adult↗

Pharmacokinetics of ertapenem in healthy young volunteers.

Ertapenem (INVANZ) is a new once-a-day parenteral beta-lactam antimicrobial shown to be effective as a single agent for treatment of various community-acquired and mixed infections. The single- and multiple-dose pharmacokinetics of ertapenem at doses up to 3 g were examined in healthy young men and women volunteers. Plasma and urine samples collected were analyzed using reversed-phase high-performance liquid chromatography with UV detection. Ertapenem is highly bound to plasma protein. The protein binding changes from approximately 95% bound at concentrations of <50 micro g/ml to approximately 92% bound at concentrations of 150 micro g/ml (concentration at the end of a 30-min infusion following the 1-g dose). The nonlinear protein binding of ertapenem resulted in a slightly less than dose proportional increase in the area under the curve from 0 h to infinity (AUC(0- infinity )) of total ertapenem. The single-dose AUC(0- infinity ) of unbound ertapenem was nearly dose proportional over the dose range of 0.5 to 2 g. The mean concentration of ertapenem in plasma ranged from approximately 145 to 175 micro g/ml at the end of a 30-min infusion, from approximately 30 to 34 micro g/ml at 6 h, and from approximately 9 to 11 micro g/ml at 12 h. The mean plasma t(1/2) ranged from 3.8 to 4.4 h. About 45% of the plasma clearance (CL(P)) was via renal clearance. The remainder of the CL(P) was primarily via the formation of the beta-lactam ring-opened metabolite that was excreted in urine. There were no clinically significant differences between the pharmacokinetics of ertapenem in men and women. Ertapenem does not accumulate after multiple once-daily dosing.

Adult↗

A phase I and pharmacological study of the farnesyl protein transferase inhibitor L-778,123 in patients with solid malignancies.

This Phase I study was performed to assess the feasibility of administering L-778,123, a peptidomimetic farnesyl protein transferase (FPTase) inhibitor, as a continuous i.v. infusion for 7 days every 3 weeks and to determine the recommended dose for subsequent disease-directed trials. This study also sought to characterize the pharmacological behavior of L-778,123 and to determine whether the desired biological effect, inhibition of protein farnesylation, could be detected and assessed during treatment. Patients with advanced solid malignancies were treated with L-778,123 as a continuous i.v. infusion for 7 days every 3 weeks at doses ranging from 35 to 1120 mg/m(2)/day. On the basis of preclinical studies, toxicity assessments included cardiac telemetry, electrocardiograms, and electroretinograms in addition to more routine safety monitoring laboratory tests. Plasma sampling was performed to characterize the pharmacokinetics of L-778,123, and peripheral blood mononuclear cells (PBMCs) were sampled to detect and monitor the inhibitory effects of L-778,123 on the prenylation of HDJ2, a chaperone protein that undergoes farnesylation. Twenty-five patients received 51 complete courses of L-778,123. An unacceptably high incidence of dose-limiting toxicities, consisting of grade 4 thrombocytopenia, significant prolongation of the QT(c) interval, and profound fatigue, was observed at the 1120 mg/m(2)/day dose level. At the next lower L-778,123 dose level, 560 mg/m(2)/day, seven new patients had no unacceptable toxicity. Instead, myelosuppression was mild to moderate and QT(c) prolongation was negligible. Pharmacokinetics were linear, and L-778,123 plasma concentrations at steady-state (mean, 8.09 +/- 3.11 microM at 560 mg/m(2)/day) exceeded IC(50) values (range, 0.07-5.35 microM) required for growth inhibition and cytotoxicity in preclinical studies. The systemic clearance of L-778,123 averaged 106.4 +/- 45.6 ml/min/m(2), and the terminal half-life of elimination was 2.8 +/- 1.0 h. L-778,123 inhibited HDJ2 prenylation for the duration of the drug infusion in a dose-dependent manner, but seemed to plateau above 560 mg/m(2)/day. At the 560 mg/m(2)/day dose level, the mean percentage of HDJ2 protein in its unprenylated form increased from 1.41% +/- 1.71% (pretreatment) to 28.76% +/- 6.10% (day 4) and 30.86 +/- 4.96 (day 8) and declined to 2.28% +/- 2.11% one week after drug discontinuation (day 16). L-778,123 administered as a continuous 7-day i.v. infusion for 7 days every 21 days is well tolerated at doses of 560 mg/m(2)/day and results in biologically relevant concentrations and consistent inhibition of HDJ2 prenylation in PBMCs. Although the relationship between drug-related inhibition of HDJ2 prenylation in PBMCs and both prenylation of relevant proteins and growth inhibition in tumor cells is unknown, serial analyses of HDJ2 prenylation provide a pharmacodynamic marker of protein prenylation that may be useful in optimizing the development of drugs targeting FPTase.

Adult↗

Trimethoprim/sulfamethoxazole does not affect the steady-state disposition of indinavir.

This study evaluates the safety and potential pharmacokinetic interaction between indinavir and trimethoprim/sulfamethoxazole (TMP/SMZ). In a randomized, three-period crossover fashion, 12 healthy adults received 1 week of indinavir sulfate 400 mg orally every 6 hours with placebo, TMP 160 mg/SMZ 800 mg orally every 12 hours with placebo, and indinavir sulfate with TMP/SMZ. Plasma indinavir, SMZ, and TMP concentrations were determined after the last dose of each treatment period. Concomitant administration resulted in a 17% decrease in geometric mean trough plasma indinavir concentrations (p = 0.032), an 18% increase in geometric mean AUC0-12 h and Cmax TMP values (p = 0.031 and 0.030, respectively), and a 5% increase in geometric mean AUC0-12 h SMZ values (p = 0.039). None of these effects was considered clinically significant. The combination of indinavir sulfate and TMP/SMZ is generally well tolerated, with no clinically significant pharmacokinetic interaction being noted.

Abdominal Pain↗

Factors influencing the emergence of resistance to indinavir: role of virologic, immunologic, and pharmacologic variables.

A major problem with the use of human immunodeficiency virus type 1 (HIV-1) protease inhibitors as monotherapy has been an unacceptably high rate of emergence of resistance. To examine possible influences on the time to emergence of resistance, 24-week data were examined from five studies in which indinavir had been administered as monotherapy or as a component of combination therapy. Monotherapy data indicated a correlation between the level of HIV-1 RNA achieved and the risk of emergence of resistance: the lower the level, the lower the risk. When combination and monotherapy regimens were compared, the group receiving indinavir + lamivudine + zidovudine had a significantly lower risk of resistance, even after adjusting for the minimum HIV-1 RNA level achieved. The findings indicate that if at all possible, HIV-1-infected patients should receive combination chemotherapy to minimize the emergence of resistance to the protease inhibitor portion of the regimen. The goal of therapy should be to decrease the HIV-1 RNA load to a less-than-detectable level.

Anti-HIV Agents↗

Effect of fluconazole on indinavir pharmacokinetics in human immunodeficiency virus-infected patients.

To evaluate a potential pharmacokinetic interaction of coadministration of fluconazole, and indinavir, a human immunodeficiency virus (HIV) protease inhibitor, 13 patients were enrolled in a multiple-dose, three-period, placebo-controlled, crossover study. Patients were randomly assigned to receive indinavir at 1,000 mg every 8 h for 7 1/3 days (with fluconazole placebo), fluconazole at 400 mg once daily for 8 days (with indinavir placebo), and indinavir with fluconazole in combination. The pharmacokinetics of both drugs were measured on day 8 of each treatment period. The peak concentration in plasma (Cmax) and the time to reach Cmax were obtained by inspection, and the area under curve (AUC) was calculated for indinavir and fluconazole for each treatment period in which the respective drugs were administered. There was a marginally (P = 0.08) statistically significant decrease in the AUC from 0 to 8 h (AUC(0-8)) for indinavir when it was administered with fluconazole. However, the magnitudes of the decreases in Cmax and the concentration at 8 h postdosing (C8) were not as great as the decrease in AUC(0-8). Although the 90% confidence interval for the geometric mean ratio was within the hypothesized limits, the clinical significance is not clear. Indinavir coadministration with fluconazole had no statistically (P > 0.5) or clinically significant effect on the Cmax and C8 of indinavir. Fluconazole coadministration with indinavir had no statistically or clinically significant effect on the pharmacokinetics of fluconazole. One patient was discontinued because of mild to moderate abdominal pain and diarrhea while on indinavir and fluconazole in combination. No serious adverse experience according to the results of laboratory tests was noted. Total bilirubin levels in serum were mildly increased in most patients treated with indinavir. This was not clinically significant and was not affected by the coadministration of fluconazole. Although the values of the pharmacokinetic parameters for indinavir decrease in the presence of fluconazole, indinavir and fluconazole can be administered concomitantly to HIV-infected patients without adjustment of the dose of either drug, and both drugs are generally well tolerated.

Adolescent↗

In vivo selection of HIV-1 variants with reduced susceptibility to the protease inhibitor L-735,524 and related compounds.

L-735,524 is a potent inhibitor of the HIV-1 protease. In cell culture, the compound interferes with virus replication by causing production of noninfectious immature viral particles containing an unprocessed gag-pol polyprotein. Initial human clinical studies demonstrated that treatment with the inhibitor caused circulating viral levels to decline and this decline was associated with increases in the CD4 count of varying magnitude. However, in most patients, antiviral activity is lost as viral variants with reduced susceptibility to the inhibitor are selected. The resistant phenotype appears to require an amino acid substitution at protease codon 82. However, this amino acid alteration alone is insufficient for expression of the resistance phenotype. Co-expression of various additional alterations seems to be required, but the nature of these additional substitutions differs among resistant isolates. HIV-1 variants, cross-resistant to a panel of structurally diverse protease inhibitors, were isolated from patients following prolonged L-735,524 therapy.

Antiviral Agents↗

[Torsades de pointes in a patient under long-term maprotiline therapy. Apropos of a case].

The authors report the case of a patient who presented with wave burst arrhythmia related to long-term treatment with maprotiline. This case is interesting, as few cases of this type of complication have been reported in patients receiving long-term tetracyclic antidepressants, and the development of such a complication indicates the need for regular electrocardiographie surveillance of patients treated with heterocyclic antidepressants. Lastly, prolonged intensive care monitoring is required in the case of maprotiline-induced wave burst arrhythmia.

Aged↗

Viral dynamics in human immunodeficiency virus type 1 infection.

The dynamics of HIV-1 replication in vivo are largely unknown yet they are critical to our understanding of disease pathogenesis. Experimental drugs that are potent inhibitors of viral replication can be used to show that the composite lifespan of plasma virus and virus-producing cells is remarkably short (half-life approximately 2 days). Almost complete replacement of wild-type virus in plasma by drug-resistant variants occurs after fourteen days, indicating that HIV-1 viraemia is sustained primarily by a dynamic process involving continuous rounds of de novo virus infection and replication and rapid cell turnover.

Antiviral Agents↗

[Pulmonary embolism associated with right auricular thrombus. Apropos of 2 cases].

The authors report two cases of serious pulmonary embolism, derived from venous thrombus (inferior vena cava in one case, superficial femoral vein in the other), associated with mobile thrombus of the right auricle, with a very rapidly favourable course after intravenous fibrinolysis. This treatment was extremely effective, allowing rapid haemodynamic improvement and resolution of the thrombus in less than 24 hours. No major haemorrhagic complications or recurrent emboli were observed. Fibrinolysis, in serious pulmonary embolism associated with thrombus of the right auricle, therefore appears to be a useful treatment, particularly in patients admitted to centres in which emergency embolectomy cannot be performed.

Aged↗

Cooperation between retinoic acid and phorbol esters enhances human teratocarcinoma differentiation.

This study explored cooperation between the retinoic acid (RA) and protein kinase C (PKC) pathways during differentiation of the multipotential human teratocarcinoma (TC) cell line NTERA-2 clone D1 (abbreviated NT2/D1). We report here that, compared to RA treatment alone, RA combined with the PKC stimulator 12-O-tetradecanoylphorbol-13-acetate (TPA) enhanced the regulated expression of the immunophenotypic differentiation markers SSEA-3, a globo-series carbohydrate, and the ganglio-series carbohydrate antigens GD2 and GD3. Northern analysis and transient transfection assays revealed that TPA co-treatment augmented the RA-induced expression and activation of the RA nuclear receptor-beta (RAR-beta), one early marker of RA response in NT2/D1 cells. This finding was extended with transient co-transfection experiments using a PKC-alpha expression vector which revealed that the PKC pathway can augment the activation of RAR-beta by RA. These experiments establish PKC as a modulator of RAR-beta expression in NT2/D1 cells. Similarly, experiments showed that RA can modulate activation of the PKC-responsive AP-1 complex, a transcription factor rapidly activated by TPA. Northern analysis and transient transfection assays revealed that, compared to TPA treatment alone, RA and TPA augmented the expression and transcriptional activity of AP-1 in NT2/D1 cells. In contrast, transient transfection assays revealed no cooperative effect between RA and TPA in HeLa cells, indicating that this effect in NT2/D1 cells is cell type-specific. In summary, these studies show that stimulation of the PKC second messenger pathway can modulate tumor differentiation and transcriptional activation of a retinoid receptor associated with RA response.

Biomarkers↗