Long-term intravenous hydroxyurea infusions in patients with advanced cancer. A phase I trial

BACKGROUND: Hydroxyurea is an S-phase specific drug. Constant exposure of tumor cells with a low S-phase fraction to the agent may result in improved cell kill. Because of its short half-life, a continuous intravenous infusion may result in better tumor exposure than intake by mouth. The goal of this trial was to find the longest tolerable duration of a continued intravenous infusion of hydroxyurea (HU) given at escalating doses. METHODS: Eligible patients had histologically confirmed cancer without effective alternate therapy, normal blood counts, liver and kidney function. After giving informed consent, the infusion began via a permanent indwelling catheter utilizing a portable pump. Dose levels (in g/m2/d) were 0.5 for level I, 1.0 for level II, 1.66 for level III, and 2.5 for level IV. RESULTS: Fourteen patients were entered. Five were men. Median age was 56 years of age (range: 32-67), median performance status 1 (range: 0-2). Diagnoses were as follows: colorectal cancer, seven; unknown primary site, three; breast cancer, two; melanoma, one; and adenoid-cystic carcinoma, one. Nine patients were pretreated with chemotherapy. Three patients were entered per dose level, except on level I, were five were entered. The mean duration of infusion was 12 weeks on level I, 5 weeks on II, 3 on III, 1 on IV. Toxicity included leukopenia below 2.0 K/mm3 in one patient each on levels III and IV, thrombocytopenia below 100 K/mm3 in one patient each on levels II and IV, and stomatitis in three patients (one on level II and two on IV). This toxicity was dose limiting. One patient on level III, with an unknown primary, had an objective response. HU levels were measured by a modification of the Fabricius-Rajewsky method. Mean plasma levels in micrograms per milliliter (SEM) were as follows: level I, 3.6 (0.23); level II, 5.1 (0.57); level III, 10.1 (1.55); and level IV, 16.7 (one point). Fetal hemoglobin rose two-fold and five-fold in two patients on level I after 9 and 16 weeks on therapy, respectively. CONCLUSIONS: HU as a continuous intravenous infusion is well tolerated; the maximum duration of therapy is related inversely with the dose given. No major antitumor activity was seen. The greatest interest in the drug rests in its future use as a modulator and radiation potentiator. The increase in hemoglobin F was of interest and may be important in the treatment of sickle cell disease.     

A clinical comparison of two triphasic oral contraceptives with levonorgestrel or norethindrone: a prospective, randomized, single-blind study

Menstrual bleeding patterns were investigated in young women taking either a levonorgestrel triphasic, Triquilar, or a norethindrone triphasic, Ortho 7/7/7, two commonly prescribed low-dose oral contraceptives. The levonorgestrel triphasic contains ethinyl estradiol (EE) 30 micrograms + levonorgestrel (LNG) 50 micrograms for the first six days, EE 40 micrograms + LNG 75 micrograms for the following five days, and EE 30 micrograms + LNG 125 micrograms for the last ten days. The norethindrone triphasic contains EE 35 micrograms + norethindrone (NET) 0.5 mg for the first seven days, EE 35 micrograms + NET 0.75 mg for the following seven days and EE 35 micrograms + NET 1.0 mg for the last seven days. Three hundred women from 16 to 25 years of age were randomized to the levonorgestrel triphasic (n = 150) or the norethindrone triphasic (n = 150) groups. Assessments were made from daily diary cards and from bimonthly investigator interviews over 6 pill cycles. The results showed a higher incidence of intermenstrual bleeding (breakthrough bleeding and/or spotting) in the norethindrone triphasic group (NET group) than in the levonorgestrel triphasic group (LNG group): 44.9% of patients (66/147) randomized to the LNG group reported intermenstrual bleeding one or more times during the study compared with 61.9% (91/147) randomized to the NET group (p = 0.0036). Furthermore, in subjects who did not miss any pills, the proportion of patients with intermenstrual bleeding in each cycle was significantly greater (p < 0.02, cycles 1-4, 6; p > 0.05, cycle 5) and was experienced for more days per cycle (p < 0.05, cycle 1) and for more cycles per patient (p < 0.05, 5 cycles) in the NET group compared with the LNG group. Intermenstrual bleeding was also less frequently observed in the LNG group than in the NET group in patients who missed pills (p < 0.05, cycles 3, 5 and 6). In addition, early withdrawal bleeding occurred more often in the NET group than in the LNG group (p < 0.05, cycles 1, 3 and 4). The incidence of amenorrhea was similar in both groups. These results demonstrate a significantly lower incidence of intermenstrual bleeding and therefore better cycle control with the levonorgestrel triphasic Triquilar, compared with the norethindrone triphasic Ortho 7/7/7.     

Redefining the growth of the heterosexual HIV/AIDS epidemic in Chicago

A 38-year-old male with bilateral pseudo-internuclear ophthalmoplegia (-INO) in myasthenia that could have been misdiagnosed as INO in multiple sclerosis is reported. He experienced fluctuating symptoms including double vision, imbalance, and tinnitus. His eye movements simulated bilateral INO, with a downshoot in abduction. After thymectomy, his eye movements became normal. From our case and a review of the literature, we propose that ptosis, downshoot, and fatigability are likely to be signs of pseudo-INO in myasthenia, whereas an impaired vertical smooth pursuit is unlikely. Dissociated nystagmus and monocular overshoot might be the results of central compensation.     

Alterations in N-acetylation of 3-methylhistidine in endotoxemic parenterally fed rats

N-methylhistidine (3-meH) is endogenously released during muscle catabolism and serves as a marker of protein turnover. In rats > 85% of 3-meH is excreted in the urine as the N-acetyl derivative. It has been reported that the percent of non-acetylated 3-meH (NA-3-meH) varies minimally with stress. To further evaluate these reports we randomized 39 male Sprague-Dawley rats (157-213 g) to receive parenteral nutrition only (PN) or PN plus continuous infusion of Escherichia coli 026:B6 lipopolysaccharide at 6 (LPS-6) or 12 (LPS-12) mg.kg-1.d-1 for 48 h. All animals received isocaloric and isonitrogenous PN 24 h before and throughout the study with water ad libitum. Total 3-meH excretion was significantly increased (P < 0.05) in the LPS-6 (470 +/- 136 micrograms/48 h) and LPS-12 (557 +/- 171 micrograms/48 h) groups versus the PN (331 +/- 126 micrograms/48 h) group. NA-3-meH differed significantly between the LPS-12 (218 /+- 89 micrograms/48 h, LPS-6 (94 +/- 48 micrograms/48 h), and PN (39 +/- 12 micrograms/48 h) groups (P < 0.05). Percent NA-3-meH increased significantly from 12.7 +/- 3.9% in the PN group to 19.8 +/- 8.0 and 39.9 +/- 12.8% in the LPS-6 and LPS-12 groups, respectively (P < 0.05). No significant changes in acetyl 3-meH were found between groups. These data suggest that either saturation or inhibition of acetylation pathways occurs with increasing levels of stress. Due to the disproportionate increases in NA-3-meH and percent NA-3-meH during endotoxemia, only total 3-meH should be used as an indicator of protein turnover in rats.     

Purification, physicochemical characterization and biological properties of a lectin from Erythrina velutina forma aurantiaca seeds

A lectin was purified from seeds of Erythrina velutina forma aurantiaca by affinity chromatography on cross-linked guar gum. The lectin is a potent agglutinin for human (minimal concentration of protein able to cause visible agglutination of a 2% erythrocyte suspension varying from 1 to 4 micrograms/ml), rabbit (4 micrograms/ml) and chicken erythrocytes (8 micrograms/ml) but presented low activity against cow (250 micrograms/ml) or sheep (333 micrograms/ml) blood cells. Hemagglutination of human O+ erythrocytes was inhibited by D-lactose (0.2 mM) > D-galactose (0.8 mM) > D-raffinose (2.1 mM). At pH 7.5, chromatography on a Superose 12 HR 10/30 column showed that the lectin was primarily a dimer (56.0 kDa) composed of two identical subunits (31.6 kDa each). A small amount of a tetrameric form was also apparently present. The lectin is a glycoprotein (7.3% carbohydrate), has a pI of 4.5, contains high levels of acidic (Asp and Glu, 64.2 and 51.6 residues/mol, respectively) and hydroxy amino acids (Ser and Thr, 42.9 and 38.5 residues/mol, respectively) but relatively low amounts of sulfur amino acids (Cys and Met, 1.0 and 5.0 residues/mol, respectively) and has an N-terminal sequence of Val-Glu-Thr-Ile/Leu-Pro-Phe-Ser. Its hemagglutinating activity was abolished by heating at 70 degrees C for 10 min. The activation energy (delta G') required for denaturation measured by loss of hemagglutination activity was 24.87 kcal/mol. In rats, the purified lectin (100 micrograms) induced neutrophil migration into the peritoneal cavity (3.7 +/- 0.6 x 10(6) neutrophils/ml) or into the air pouch (2.75 +/- 0.25 x 10(6) neutrophils/ml), 8 and 10 times greater than the negative control, respectively.