Conventional Radiograph Is Still Advised in the Diagnostic Work-up of a Shoulder Dislocation; a Letter to the Editor

Dear editor: A shoulder dislocation is a common diagnosis at the emergency department, showing an incidence of 23.9 per 100,000 person-years. In the current diagnostic work-up, a radiograph is often used to confirm the dislocation. As radiographs are associated with radiation exposure, the ultrasound has been proposed as an alternative. Therefore, the study by Entezari et al is of great importance in evaluating the applicability of the ultrasound. However, the authors suggest that the ultrasound can be used as an alternative to the radiograph. In our opinion, an important advantage of the radiograph has not been discussed and we question some decisions that were made in terms of methodology. Therefore, we think that this study has to be seen in the light of these remarks

Production and characterization of monoclonal antibodies raised against recombinant human granzymes A and B and showing cross reactions with the natural proteins

The human serine proteases granzymes A and B are expressed in cytotoplasmic granules of activated cytotoxic T lymphocytes and natural killer cells. Recombinant granzyme A and granzyme B proteins were produced in bacteria, purified and then used to raise specific mouse monoclonal antibodies. Seven monoclonal antibodies (mAb) were raised against granzyme A, which all recognized the same or overlapping epitopes. They reacted specifically in an immunoblot of interleukin-2 (IL-2) stimulated PBMNC with a disulfide-linked homodimer of 43 kDa consisting of 28 kDa subunits. Seven mAb against granzyme B were obtained, which could be divided into two groups, each recognizing a different epitope. On an immunoblot, all mAb reacted with a monomer of 33 kDa protein. By immunohistochemistry, these mAb could be used to detect granzymes A and B expression in activated CTL and NK cells. The availability of these mAb may facilitate studies on the role of human cytotoxic cells in various immune reactions and may contribute to a better understanding of the role of granzmes A and B in the cytotoxic response in vivo

Effects of St. John's wort on irinotecan metabolism

St. John's wort (SJW), a widely used herbal product, has been implicated in drug interactions resulting from the induced expression of the cytochrome P450 CYP3A4 isoform. In this study, we determined the effect of SJW on the metabolism of irinotecan, a pro-drug of SN-38 and a known substrate for CYP3A4. Five cancer patients were treated with irinotecan (350 mg/m(2), intravenously) in the presence and absence of SJW (900 mg daily, orally for 18 days) in an unblinded, randomized crossover study design. The plasma levels of the active metabolite SN-38 decreased by 42% (95% confidence interval [CI] = 14% to 70%) following SJW cotreatment with 1.0 micro M x h (95% CI = 0.34 micro M x h to 1.7 micro M x h) versus 1.7 micro M x h (95% CI = 0.83 micro M x h to 2.6 micro M x h) (P =.033, two-sided paired Student's t test). Consequently, the degree of myelosuppression was substantially worse in the absence of SJW. These findings indicate that patients on irinotecan treatment should refrain from taking SJW because plasma levels of SN-38 were dramatically reduced, which may have a deleterious impact on treatment outcome

Determination of irinotecan (CPT-11) and its active metabolite SN-38 in human plasma by reversed-phase high-performance liquid chromatography with fluorescence detection

Sensitive high-performance liquid chromatographic assays have been developed to determine the levels of the lactone and lactone plus carboxylate (total) forms of the antitumor agent irinotecan (CPT-11) and its active metabolite SN-38, in human plasma. The related compound camptothecin was used as the internal standard. The selective sample pretreatment for the lactone forms involved a single solvent extraction with acetonitrile-n-butyl chloride (1:4, v/v), whereas the sample clean-up for the total forms was a simple protein precipitation with aqueous perchloric acid-methanol (1:1, v/v), which results in the conversion of the carboxylate to the lactone forms. Chromatography was carried out on a Hypersil ODS column, with detection performed fluorimetrically. The methods have been validated, and stability tests under various conditions have been performed. The lower limits of quantitation are 0.5 and 2.0 ng/ml for the lactone and total forms, respectively. The assays have been used in a single pharmacokinetic experiment in a patient to investigate the applicability of the method in vivo

Factors involved in prolongation of the terminal disposition phase of SN-38: clinical and experimental studies

The active metabolite of irinotecan (CPT-11), 7-ethyl-10-hydroxycamptothecin (SN-38), is either formed through enzymatic cleavage of CPT-11 by carboxyl esterases (CEs) or through cytochrome P-450 3A-mediated oxidation to 7-ethyl-10-[4-(1-piperidino)-1-amino] carbonyloxycamptothecin (NPC) and a subsequent conversion by CE. In the liver, SN-38 is glucuronidated (SN-38G) by UGT1A1, which also conjugates bilirubin. Fourteen patients were treated with 350 mg/m2 CPT-11, and we performed pharmacokinetic analysis during a 500-h collection period. The half-life and area under the plasma concentration-time curve of SN-38 were 47+/-7.9 h and 2.0+/-0.79 microM x h, respectively, both representing a 2-fold increase as compared with earlier reported estimates (A. Sparreboom et al, Clin. Cancer Res., 4: 2747-2754, 1998). As an explanation for this phenomenon, we noted substantial formation of SN-38 from CPT-11 and NPC by plasma CE, consistent with the low circulating levels of NPC observed. In addition, transport studies in Caco-2 monolayers indicated that nonglucuronidated SN-38 could cross the membrane from apical to basolateral, indicating the potential for recirculation processes that can prolong circulation times. Interestingly, individual levels of fecal beta-glucuronidase, which is known to mediate SN-38G hydrolysis, were not related to any of the SN-38 kinetic parameters (r = 0.09; P = 0.26), suggesting that interindividual variation in this enzyme is unimportant in explaining SN-38 pharmacokinetic variability. We have also found, in contrast to earlier data, that SN-38G/SN-38 plasma concentration ratios decrease over time from approximately 7 (up to 50 h) to approximately 1 (at 500 h). This decrease could be explained by the fact that glucuronidation of SN-38 and bilirubin is increasingly competitive at lower drug levels. In addition, no evidence was found for SN-38G transport through the Caco-2 cells. Our findings indicate that until now the circulation time of SN-38 has been underestimated. This is of crucial importance to our understanding of the clinical action of CPT-11 and for future pharmacokinetic/pharmacodynamic relationships

Measurement of fraction unbound paclitaxel in human plasma

The clinical pharmacokinetic behavior of paclitaxel (Taxol) is distinctly nonlinear, with disproportional increases in systemic exposure with an increase in dose. We have recently shown that Cremophor EL, the formulation vehicle used for i.v. administration of paclitaxel, alters drug distribution as a result of micellar entrapment of paclitaxel, and we speculated that the free drug fraction (fu) is dependent on dose and time-varying concentrations of Cremophor EL in the central plasma compartment. To test this hypothesis, a reproducible equilibrium dialysis method has been developed for the measurement of paclitaxel fu in plasma. Equilibrium dialysis was performed at 37 degrees C in a humidified atmosphere of 5% CO(2) using 2.0-ml polypropylene test tubes. Experiments were carried out with 260-microliter aliquots of plasma containing a tracer amount of [G-(3)H]paclitaxel with high-specific activity against an equal volume of 0.01 M phosphate buffer (pH 7.4). Drug concentrations were measured by both reversed-phase HPLC and liquid scintillation counting. Using this method, fu has been measured in three patients receiving three consecutive 3-weekly courses of paclitaxel at dose levels of 135, 175, and 225 mg/m(2) and found to range between 0.036 and 0.079. The method was also used to define concentration-time profiles of unbound drug, estimated from the product of the total plasma concentration and fu

Disposition of [G-(3)H]paclitaxel and cremophor EL in a patient with severely impaired renal function

In the present work, we studied the pharmacokinetics and metabolic disposition of [G-(3)H]paclitaxel in a female patient with recurrent ovarian cancer and severe renal impairment (creatinine clearance: approximately 20 ml/min) due to chronic hypertension and prior cisplatin treatment. During six 3-weekly courses of paclitaxel at a dose level of 157.5 mg/m(2) (viz. a 10% dose reduction), the renal function remained stable. Pharmacokinetic evaluation revealed a reproducible and surprisingly high paclitaxel area under the plasma concentration-time curve of 26.0 +/- 1.11 microM.h (mean +/- S.D.; n = 6; c.v. = 4.29%), and a terminal disposition half-life of approximately 29 h. Both parameters are substantially increased ( approximately 1.5-fold) when compared with kinetic data obtained from patients with normal renal function. The cumulative urinary excretion of the parent drug was consistently low and averaged 1.58 +/- 0.417% (+/- S.D.) of the dose. Total fecal excretion (measured in one course) was 52.9% of the delivered radioactivity, and mainly comprised known mono- and dihydroxylated metabolites, with unchanged paclitaxel accounting for only 6.18%. The plasma area under the plasma concentration-time curve of the paclitaxel vehicle Cremophor EL, which can profoundly alter the kinetics of paclitaxel, was 114.9 +/- 5.39 microl.h/ml, and not different from historic data in patients with normal or mild renal dysfunction. Urinary excretion of Cremophor EL was less than 0.1% of the total amount administered. These data indicate that the substantial increase in systemic exposure of the patient to paclitaxel relates to decreased renal metabolism and/or urinary elimination of polar radioactive species, most likely lacking an intact taxane ring fragment

Modulation of irinotecan-induced diarrhea by cotreatment with neomycin in cancer patients

This study was designed to evaluate irinotecan (CPT-11) disposition and pharmacodynamics in the presence and absence of the broad-spectrum antibiotic neomycin. Seven evaluable cancer patients experiencing diarrhea graded > or =2 after receiving CPT-11 alone (350 mg/m(2) i.v. once every 3 weeks) received the same dose combined with oral neomycin at 1000 mg three times per day (days -2 to 5) in the second course. Neomycin had no effect on the systemic exposure of CPT-11 and its major metabolites (P > or = 0.22). However, it changed fecal beta-glucuronidase activity from 7.03 +/- 1.76 microg/h/mg (phenolphthalein assay) to undetectable levels and decreased fecal concentrations of the pharmacologically active metabolite SN-38. Although neomycin had no significant effect on hematological toxicity (P > 0.05), diarrhea ameliorated in six of seven patients (P = 0.033). Our findings indicate that bacterial beta-glucuronidase plays a crucial role in CPT-11-induced diarrhea without affecting enterocycling and systemic SN-38 levels

A modified Delphi study to identify which items should be evaluated in shoulder instability research:a first step in developing a core outcome set

Background: The aim of this study was to identify items that healthcare providers and/or patients consider important to include in a questionnaire for clinical trials and cohort studies in shoulder instability research. This could serve as a basis to develop a core outcome set for shoulder instability research. Methods: Healthcare providers and patients were included in a panel for a modified Delphi consensus study. The study consisted of three rounds, comprising (1) identifying items, (2) rating the importance of the items, and (3) rating the importance again after seeing a summary of the results of round two. Importance was rated on a 9-point Likert scale. Consensus was defined as ≥ 80% of the panel giving a score of 7 or higher. Results: In total, 44 healthcare providers and 30 patients completed all three rounds. Round one identified 54 items. After round three, the panel reached a consensus on 11 items that should be included in a questionnaire, comprising re-dislocation (99%), instable feeling of the shoulder (96%), limitations during sport (93%), patient satisfaction with the shoulder (93%), fear/anxiety for re-dislocation (91%), range of motion (88%), return to old level of functioning (85%), performing daily activities (85%), return to sport (82%), return to work (82%), and trusting the shoulder (81%). Conclusion: Healthcare providers and patients reached a consensus on 11 items that should be included in a questionnaire for shoulder instability research. These items can facilitate design and development of future clinical trials and form the basis for the development of a core outcome set.</p