Frequent administration of Dabis Maleate, a phase I study.

Dabis Maleate (1,4-bis(2'-chloroethyl)-1,4-diazabicyclo[2.2.1] Heptane dihydrogen dimaleate) (NSC 262666) is an alkylating quaternary nitrogen compound. In a previous phase I study using a once-every-3-weeks administration the dose-limiting toxicity was neurotoxicity and the recommended dose for phase II studies was 750 mg/m2 iv every 3 weeks. In vitro studies suggested a higher activity after more frequent administration, and in vivo studies a better therapeutic index with prolonged infusion. We studied 11 patients with solid tumors. Dose levels tested ranged from 250-750 mg/m2, either as a day 1-3 regimen or weekly, the latter as bolus administration or as prolonged infusion. The dose-limiting toxicity was neurotoxicity consisting of paresthesias and ataxia. Nausea and vomiting were moderate. No other major toxicity was observed. The dose recommended for phase II studies is 500 mg/m2/week as a 6-hour iv infusion for 6 weeks, followed by a 3-week rest period.     

Characteristics of sensory trick-like manoeuvres in jaw-opening dystonia.

We evaluated the effect of different manipulations on the performance of a standardized counting task in 7 patients with idiopathic jaw-opening dystonia. Patients used a small stick as sensory stimulus. Following conditions were examined: stick placed between teeth and cheek (CHEEK), biting on stick (TEETH), voluntary jaw occlusion without stick (OCCLUSION). Articulation was rated by patients and experimenters and surface electromyographic activity (EMG) was recorded. Patient-rating (CHEEK - 36.6%, TEETH - 48.1%) and EMG (-18.1%; -17.3%) were significantly improved for conditions using the stick, whereas experimenter-rating showed a trend for TEETH (-16.2%). Although jaw occlusion during speaking deteriorates articulation in healthy subjects, there was no further deterioration in patients and EMG was even significantly reduced (-18.6%). Comparable results were obtained in 1 patient using a special dental device. We conclude that sensory tricks significantly improve subjective and objective parameters. Besides tactile stimulation, altered proprioceptive feedback and antagonist activation may modulate hyperactive dystonic networks.     

Safety of virus inactivated antithrombin III concentrate ANTITHROMBIN III IMMUNO (AT III)

In a prospective clinical trial the risk of infection after application of virus inactivated antithrombin III concentrate ANTITHROMBIN III IMMUNO (AT III) was investigated in patients undergoing cardiovascular surgery. The study was conducted according to the recommendations of the International Committee on Thrombosis and Hemostasis (ICTH), with the exception that most patients required additional blood products as well as AT III.

Twenty-seven patients were eligible to test for the risk of acquiring hepatitis B. Twenty-six patients could be evaluated in terms of hepatitis NANB transmission considering ALT-levels whereas 20 patients could be tested for anti-HCV one year after surgery. Samples from 78 patients could be monitored for anti-HIV-1. None of these patients showed any signs of infection. AT III IMMUNO seems to be an antithrombin III concentrate with low or absent infectivity.     

Paraneoplastic hypercalcemia associated with adenosquamous carcinoma of the endometrium

Paraneoplastic hypercalcemia associated with adenosquamous carcinoma of the endometrium is described. This is the first reported case of a gynecologic cancer in which the paraneoplastic syndrome has been conclusively shown by immunohistochemical analysis to be due to ectopic parathormone.     

Effect of parathyroid hormone on bicarbonate absorption by proximal tubules in vitro.

The effect of parathyroid hormone on bicarbonate absorption was tested in rabbit proximal renal tubules perfused in vitro. In proximal straight tubules 0.05 U/ml of parathyroid hormone caused a large and reversible increase in the steady-state bicarbonate concentration in tubule fluid. Further, the rates of bicarbonate and fluid absorption (measured at faster flow rates) were inhibited approximately 50% by the hormone. We conclude that parathyroid hormone directly inhibits fluid and bicarbonate absorption by proximal straight tubules, causing an increase in the bicarbonate concentration in the tubule fluid, and we suggest that this action of the hormone contributes to the increase in renal bicarbonate excretion that is generally caused by the hormone. In proximal convoluted tubules, parathyroid hormone was previously demonstrated by other investigators to inhibit fluid and bicarbonate absorption approximately proportionally, so that there was little or no change in the bicarbonate concentration in tubule fluid. In agreement we found in the present studies that 0.05 U/ml of the hormone did not affect the steady-state bicarbonate concentration in proximal convoluted tubule fluid and that 5 U/ml caused only an equivocal increase in tubule fluid bicarbonate concentration.     

Origin and filiation of human plasmacytoid dendritic cells

Human plasmacytoid dendritic cells represent a rare population of leukocytes which produce high amounts of type I interferon in response to certain viruses. Although those cells were first described in 1958, there are still unsolved issues related to their origin and function. Recently, a leukemic counterpart of plasmacytoid dendritic cells was identified. Molecular approaches using either normal or leukemic plasmacytoid dendritic cells provide some new insights into the controversial lymphoid origin of those cells. The need for specific markers is still a critical aspect for the identification of plasmacytoid dendritic cells, whatever stage of differentiation, in normal as well as in pathological conditions. Hopefully, novel markers will allow delineation of the relationships between dendritic cells at different stages of differentiation/maturation along the myeloid and lymphoid lineages.     

Competition-based cellular peptide binding assays for 13 prevalent HLA class I alleles using fluorescein-labeled synthetic peptides

We report the development, validation, and application of competition-based peptide binding assays for 13 prevalent human leukocyte antigen (HLA) class I alleles. The assays are based on peptide binding to HLA molecules on living cells carrying the particular allele. Competition for binding between the test peptide of interest and a fluorescein-labeled HLA class I binding peptide is used as read out. The use of cell membrane-bound HLA class I molecules circumvents the need for laborious biochemical purification of these molecules in soluble form. Previously, we have applied this principle for HLA-A2 and HLA-A3. We now describe the assays for HLA-A1, HLA-A11, HLA-A24, HLA-A68, HLA-B7, HLA-B8, HLA-B14, HLA-B35, HLA-B60, HLA-B61, and HLA-B62. Together with HLA-A2 and HLA-A3, these alleles cover more than 95% of the Caucasian population. Several allele-specific parameters were determined for each assay. Using these assays, we identified novel HLA class I high-affinity binding peptides from HIVpol, p53, PRAME, and minor histocompatibility antigen HA-1. Thus these convenient and accurate peptide-binding assays will be useful for the identification of putative cytotoxic T lymphocyte epitopes presented on a diverse array of HLA class I molecules.