The expression of the p170 multidrug resistance protein by bone marrow plasma cells (BMPC) was assessed at clinical presentation in 53 patients with multiple myeloma (MM) using the C219 monoclonal antibody. Twenty-two of the 53 (41 per cent) patients had variable aliquots (1-60 per cent, median = 6 per cent) of p170+ BMPC by immunocytochemistry. Five of 10 patients studied using bivariate flow cytometry had both diploid and hyperdiploid (DNA index ranged from 1.2 to 1.5) BMPC with hyperdiploid clones having significantly greater p170 expression than diploid ones. Of the 37 patients evaluated for a response, 20 (54 per cent) had responded to induction chemotherapy. The presence of p170+ BMPC was a negative indicator for achieving response. The response rate was 75 per cent for p170- and 25 per cent for p170+ cases (p < 0.01), with no difference on the basis of treatment schedule (melphalan and prednisone, 24 patients; peptichemio, vincristine and prednisone, 13 patients). No difference in response and survival duration was found between p170+ and p170- patients. In six of nine patients studied both at diagnosis and following induction chemotherapy the p170+ BMPC% increased irrespective of the type of treatment or outcome.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMedDate not supplied

Effects of sodium arsenite exposure on development and behavior in the rat.

Arsenic is an environmental contaminant found in soil, water and air in some zones of the world. It has been widely studied for its effects as a human carcinogenic agent, but few studies have dealt with neurobehavioral effects. In addition, studies of arsenic effects on development have only addressed its effects on embryotoxicity and teratogenicity after a single oral, gavage or intraperitoneal exposure. Among the behavioral alterations reported after intoxication with arsenic are both increased and decreased locomotor activity and learning deficits in a delayed alternation task [Toxicol. Lett. 54 (1990) 345; Bull. Environ. Contam. Toxicol. 50 (1993) 100; Brain Res. Bull. 55 (2001) 301]. To further characterize developmental and behavioral alterations induced by arsenic exposure, Sprague-Dawley rats were exposed to arsenite (36.70 mg arsenic/l in drinking water) from gestation day 15 (GD 15) or postnatal day 1 (PND 1), until approximately 4 months old. The pregnant or lactating dams received either the arsenic solution or regular drinking water and once pups were weaned, they continued receiving the same solution as drinking water. Animals exposed from GD 15 showed increased spontaneous locomotor activity and both exposed groups showed increased number of errors in a delayed alternation task in comparison to the control group. Total arsenic (TA) content in brain was similar for both exposed groups and significantly different from the control group. These results indicate that rats exposed to arsenic during development present deficits in spontaneous locomotor activity and alterations in a spatial learning task.

Animals↗

PubMedDate not supplied

Thymostimulin effects on the pituitary-ovarian axis in hyperprolactinemic young female rats.

This work was undertaken to study the effects of thymostimulin on the pituitary-ovarian axis of young female rats, and to elucidate possible prolactin-mediated effects. 30-day-old rats implanted with an ectopic pituitary from a littermate male donor under the kidney capsule or sham-operated animals were injected with thymostimulin or vehicle for 2 and 8 days. Chronic thymostimulin treatment to sham-operated rats increased plasma prolactin and estradiol levels, and decreased gonadotropin levels. Thymostimulin administration to pituitary-grafted rats did not further modify the increase in plasma prolactin and the decrease in plasma luteinizing hormone levels induced by the presence of an ectopic pituitary, suggesting a hypothalamic and/or hypophysial site of action of the thymic fraction. An increase in plasma estradiol and progesterone levels was observed with the in vivo thymostimulin treatment, although differential in vitro effects on estradiol responses to human chorionic gonadotropin in the various groups studied were observed. These effects seem to be mediated through the changes in plasma prolactin and gonadotropin concentrations observed. The above-mentioned changes induced by the thymic fraction on plasma estradiol and progesterone levels might counteract prolactin effects on the thymus. These data suggest that thymostimulin treatment of young female rats changes hypophysial and sex hormone secretion, as well as the response of the ovaries to human chorionic gonadotropin, probably modifying the normal process of sexual maturation.

Animals↗

PubMedDate not supplied

Myeloprotective effect of early primary granulocyte-colony stimulating factor during six courses of intensified 5-fluorouracil, epirubicin and cyclophosphamide (120FEC) chemotherapy for advanced breast cancer. Cooperative Group of Study and Treatment of Breast Cancer.

AIMS AND BACKGROUND: The neutropenia induced by six courses of an intensified FEC regimen is expected to be checked by early primary administration of G-CSF which is stopped eight days before the next chemotherapy course. Less information is available about megakaryocytic and erythroid toxicity over six courses. METHODS AND STUDY DESIGN: Sixty-six consecutive patients with metastatic breast cancer completed six courses of a randomized treatment with two FEC regimens administered every 21 days, in which 600 mg/m2 of cyclophosphamide and 5-FUwas associated with 60 or 120 mg/m2 of epirubicin (60FEC, 35 patients, vs 120FEC, 31 patients). 120FEC was supported by early primary G-CSF (days 4 to 13). Blood counts were obtained seven times during each course. RESULTS: The non-hematologic toxicity over 364 courses was similar in 60FEC and 120FEC. No cumulative hematologic toxicity was observed for white blood cells (WBC) and platelets (PLT), while for hemoglobin (Hb) a somewhat higher cumulative toxicity was observed with 120FEC than with 60FEC. WBC, PLT and Hb grade III-IV toxicity occurred in 40.1% and 45.6% (P=ns), in 23.1% and 0.8% (P <.0001) and in 15.6% and 3.0% (P <.005) of the two regimens, respectively. There were no febrile or hemorrhagic episodes. The epirubicin relative dose intensity delivered was 1.95 in 120FEC with respect to 60FEC. CONCLUSIONS: Our G-CSF schedule permitted to deliver six courses of 120FEC without any clinically relevant side effects. Grade III-IV leukopenia was similar with 120FEC and 60FEC, while grade III-IV thrombocytopenia and anemia occurred more often with 120FEC than with 60FEC.

Adult↗

PubMedDate not supplied

Constitutive expression of glutamic acid decarboxylase (GAD) by striatal cell lines immortalized using the tsA58 allele of the SV40 large T antigen.

Rodent striatal cells were immortalized using the A58 temperature-sensitive allele of the SV40 large T antigen. Seventy-eight clones and 10 mixed cultures were characterized at the nonpermissive and permissive temperatures. Based on morphology and expression of proteins, cells were classified into three primary types, with types b and c expressing some neuronal characteristics. Type a cells have an epithelial-like morphology with coarse cytoplasmic extensions and occasional fine processes. These cells express vimentin, do not grow well under serum-free conditions and, when confluent, form a uniform monolayer. Type b cells have a polygonal shape and usually extend multiple thin processes. These cells possess large nuclei with multiple nucleoli and do not express vimentin. Type c cells have a fibroblast-like appearance, are unipolar or multipolar, and their soma is smaller than that of type b cells. Type c cells do not express vimentin, and when confluent form a uniform monolayer. Some type b and c clones express N-CAM and MAP-2. Several type b and c cell lines were found to consistently express glutamic acid decarboxylase (GAD) immunoreactivity under several tissue culture conditions. Selected cell lines were transplanted into the intact adult rat brain in several locations. Cells survived well for 15 wk and did not form tumors. The proteins expressed in vivo were similar to those expressed in vitro.

Alleles↗

PubMedDate not supplied

In vivo assessment of antiviral reactivity in chronic HIV infection.

PURPOSE AND METHOD: Chronic infection with HIV renders individuals incapable of mounting an effective host antiviral response, as defined by in vitro assays. Therefore, to determine whether antiviral reactivity could be detected in vivo, we interrupted effective antiviral treatment prospectively in nine chronically infected aviremic individuals. Low-dose interleukin-2 (IL-2) was administered before and after treatment interruption to compensate for any potential IL-2 production deficiency. In vivo antiviral reactivity was monitored subsequent to the interruption of antiviral therapy via viral and lymphocyte dynamics. The study was terminated when the plasma HIV RNA concentration reached a plateau, defined as four successive determinations that were <25% from the mean. RESULTS: Plasma viral relapse occurred in all participants; reaching a peak concentration within 2.5 weeks. However, over the subsequent 2 weeks viremia was reduced an order of magnitude coincident with a 2-fold lymphocytosis of the CD8 + T cell subset. A second treatment interruption resulted in attenuation of the peak and trough virus concentrations by <10-fold in 3 of 4 participants, while the CD8 + T cell concentrations remained elevated. CONCLUSION: These findings indicate that chronic HIV infection prior to successful antiviral therapy does not preclude host antiviral reactivity. In addition, in vivo antiviral reactivity as revealed by viral and lymphocyte dynamics after antiviral treatment interruption can be useful to monitor the efficacy of different therapies.

Antiretroviral Therapy, Highly Active↗

PubMedDate not supplied

The effects of cyclophosphamide on antibody dependent cell-mediated cytotoxicity in mice.

The effect of cyclophosphamide (CY) on antibody dependent cell-mediated cytotoxicity (ADCC) was evaluated. The results indicated that a single injection of CY markedly increased ADCC activity of murine splenic cells. This effect was dose dependent and was maximal on day 7 after the drug injection. The number of lymphoid cells in treated mice decreased to approximately 50%; however the percentages of EA rosettes were similar to those of control animals suggesting that the augmented cytotoxic activity was not due to a relative increase in Fc receptor bearing cells. CY treatment also enhanced delayed type hypersensitivity, but suppressed antibody production to sheep red blood cells. The possibility that CY eliminates a suppressor cell subpopulation that normally regulates ADCC levels is discussed.

Animals↗

PubMedDate not supplied

Paclitaxel in anthracycline-treated breast cancer patients.

Between May 1995 and July 1997, paclitaxel (TX) (175 mg/m2 by 3 h i. v. infusion every 21 days) was administered to 70 consecutive patients (median age: 57 years) previously treated with the FEC regimen (cyclophosphamide and 5-fluorouracil, 600 mg/m2, plus epirubicin, 60 or 120 mg/m2) as an adjuvant setting or as a first-line therapy for metastatic disease. Sixty-eight patients were evaluable for response, while two died early. Patients received a median of 4.7 (3-12 course) of TX for a total of 211 courses. The overall response and stable disease rate was 54% in 11 patients, who relapsed following adjuvant FEC, and 60% in 57 patients, who received FEC as first treatment for their metastatic disease. No complete respose was obtained. In patients pretreated for metastatic disease, response and stable disease rates were similar irrespective of previous response to FEC. Main hematologic toxicity of TX was of short duration, grade II/III leukopenia (86% of patients) and non-hematologic toxicity was grade II/III peripheral neuropathy, related to the cumulative dose of TX. At this schedule, TX offers a significant rate of partial responses or disease stabilization in patients with metastatic breast cancer previously treated with FEC.

Adult↗