Endodermal sinus tumor of the mediastinum. Report of apparent cure in two patients with extensive disease

Primary endodermal sinus tumor (EST) of the mediastinum has been regarded as a rare and rapidly fatal germ cell neoplasm. We describe two cases of extensive EST treated with a new high-dose sequential combination chemotherapy regimen (CISCA-VB) followed by radical surgical excision. They are alive at 11 and 20 months, respectively, postoperatively. These cases stand in marked contrast to previously reported series. A new approach to the management of this tumor is proposed.     

Analysis of human platelet glycoproteins IIb-IIIa and Glanzmann's thrombasthenia in whole blood by flow cytometry

Antibodies that bind to human platelet membrane glycoproteins IIb and IIIa were used to develop methods for analyzing platelet membrane components by flow cytometry. Platelets were tentatively identified by their low-intensity light scatter profiles in whole blood or platelet- rich plasma preparations. Identification of this cell population as platelets was verified by using platelet-specific antibodies and fluorescein-conjugated antiimmunoglobulin. Two-parameter analysis of light scatter versus fluorescence intensity identified greater than 98% of the cells in the "platelet" light scatter profile as platelets due to their acquired fluorescence. Both platelet-rich plasma and whole blood were used to study platelet membrane glycoproteins IIb and IIIa on a single cell basis in an unwashed system. Prostacycline was included in these preparations as a precautionary step to inhibit platelet aggregation during analysis. Flow cytometry is a successful technique for rapid detection of platelet membrane defects such as Glanzmann's thrombasthenia. Platelets from Glanzmann's thrombasthenic individuals were readily distinguished from platelets with normal levels of glycoprotein IIb and IIIa and from platelets with glycoprotein levels characteristic of heterozygote carriers of this disorder. This technique provides a sensitive tool for investigating platelet functional defects due to altered expression or deficiency of platelet surface proteins.     

Effects of Hydrochlorothiazide on the Pharmacokinetics,Pharmacodynamics, and Tolerability of Canagliflozin,a Sodium Glucose Co-transporter 2 Inhibitor,in Healthy Participants

Background

Many patients with type 2 diabetes mellitus (T2DM) also have hypertension, which is commonly treated with thiazide diuretics, including hydrochlorothiazide (HCTZ). Canagliflozin, a sodium glucose cotransporter 2 inhibitor developed for the treatment of T2DM, lowers plasma glucose by inhibiting renal glucose reabsorption, thereby increasing urinary glucose excretion and mild osmotic diuresis. Because patients with T2DM are likely to receive concurrent canagliflozin and HCTZ, potential interactions were evaluated.

Objective

This study evaluated the effects of HCTZ on the pharmacokinetic and pharmacodynamic properties and tolerability of canagliflozin in healthy participants.

Methods

This Phase I, single-center, open-label, fixed-sequence, 2-period study was conducted in healthy participants. During period 1, participants received canagliflozin 300 mg once daily for 7 days, followed by a 14-day washout period. During period 2, participants received HCTZ 25 mg once daily for 28 days, followed by canagliflozin 300 mg + HCTZ 25 mg once daily for 7 days. Blood samples were taken before and several times after administration on day 7 of period 1 and on days 28 and 35 of period 2 for canagliflozin and HCTZ pharmacokinetic analyses using LC-MS/MS. Blood and urine samples were collected for up to 24 hours after canagliflozin administration on day 1 of period 1 and day 35 of period 2 for pharmacodynamic glucose assessment. Tolerability was also evaluated.

Results

Thirty participants were enrolled (16 men, 14 women; all white; mean age, 43.7 years). Canagliflozin AUC during a dosing interval (T) at steady state (AUC_τ,ss) and C_max at steady state (C_max,ss) were increased when canagliflozin was coadministered with HCTZ, with geometric mean ratios (90% CI) of 1.12 (1.08–1.17) and 1.15 (1.06–1.25), respectively. AUC_τ,ss and C_max,ss for HCTZ were similar with and without canagliflozin coadministration. The 24-hour mean renal threshold for glucose and mean plasma glucose were comparable for canagliflozin alone and coadministered with HCTZ. The change in 24-hour urine volume from baseline was −0.1 L with canagliflozin alone and 0.4 L with HCTZ alone and with canagliflozin + HCTZ. The overall incidence of adverse events (AEs) was higher with canagliflozin + HCTZ (69%) than with canagliflozin (47%) or HCTZ (50%) alone; most AEs were of mild severity. Overall, minimal changes in serum electrolytes (eg, sodium, potassium) were observed after coadministration of canagliflozin + HCTZ compared with individual treatments.

Conclusions

Adding canagliflozin treatment to healthy participants on HCTZ treatment had no notable pharmacokinetic or pharmacodynamic effects; canagliflozin coadministered with HCTZ was generally well tolerated, with no unexpected tolerability concerns. ClinicalTrials.gov identifier: NCT01294631.     

Blood donor-, apheresis-, and transfusion-related activities: results of the 1991 American Association of Blood Banks Institutional Membership Questionnaire

Approximately 2154 regional blood centers and hospital-based blood banks and transfusion services responded to the 1991 American Association of Blood Banks Institutional Membership Questionnaire that elicited data from 1990. Information from 2144 institutions was considered valid. Questionnaire topics were donor blood collections, hemapheresis, perioperative cell salvage, component usage, and transfusion-associated diseases. Institutional members reported collecting 9.3 million units, of which 90.9 percent were for allogeneic use in the community, 6.0 percent were for autologous use, and 3.1 percent were directed donations. The percentage of directed-donor units that were crossed over for allogeneic use (51%) was greater than the percentage of units transfused to the designated patient (49%). Only 12.5 percent of institutions reported obtaining specific consent for transfusion. Of the 15.4 million transfused blood components, 8.5 million were red cells, 4.1 million were platelets, 1.8 million were fresh-frozen plasma, and 0.9 million were cryoprecipitate. There were 1263 reported cases of transfusion-associated hepatitis. Approximately 44 percent of the patients who were tested proved positive for hepatitis B surface antigen, and 80 percent of the patients who were tested proved positive for antibody to hepatitis C. The questionnaire's aggregate results can be used to assess current patterns of blood donation and transfusion activities.     

Monoclonal antibodies to human platelet glycoprotein IIb beta that initiate distinct platelet responses

Hybridomas secreting monoclonal antibodies (MoAbs) to human platelet membrane glycoprotein IIb (GPIIb) were prepared by fusing cells of a mouse myeloma line to spleen cells from a BALB/c mouse immunized with purified GPIIb. Six of the hybridomas secreted MoAbs that recognized epitopes on the 23,000-dalton, disulfide-linked subunit of GPIIb, GPIIb beta. All six of these MoAbs agglutinated platelets in the absence of calcium. The agglutination titers of three of the MoAbs, however, were enhanced between 2 and 6 log2 dilutions when titrated in the presence of mmol/L of calcium. The enhancement in titer was the result of MoAb- induced platelet activation followed by platelet aggregation, a reaction that could also be initiated by the monovalent Fab fragments prepared from one of the MoAbs. The MoAbs did not significantly agglutinate platelets from patients with Glanzmann's thrombasthenia, confirming biochemical evidence that there is a paucity of GPIIb beta in the membranes of these cells. Our results show that MoAbs to epitopes on GPIIb beta initiate distinct platelet responses; therefore, they should be useful for studying the ways in which regions of surface glycoproteins are involved in platelet-platelet interactions. In addition, these reagents may prove of value in diagnosing and typing patients with Glanzmann's thrombasthenia.     

The new consultation: developing doctor-patient communication. David Pendleton, Theo Schofield, Peter Tate, Peter Havelock (eds). (143 pages, {pound}19.95.) Oxford University Press, 2003. ISBN 0-19-263288

The consultation is the core of medicine. Consultations makeup more than two-thirds of the workload of a family doctor,but the number of books on the topic is surprisingly small.Those who have read these authors' first book