Oral activity of ether lipid ester prodrugs of cidofovir against experimental human cytomegalovirus infection

Infection with human cytomegalovirus (HCMV) can cause serious complications in bone-marrow and solid-organ transplant recipients, and current therapies are not optimal. We evaluated 2 orally active ether lipid ester analogues of cidofovir (CDV)--hexadecyloxypropyl-CDV (HDP-CDV) and octadecyloxyethyl-CVD (ODE-CDV)--in severe combined immunodeficient mice in which either human fetal retinal tissue or human fetal thymus and liver tissue had been implanted and was later infected with HCMV. Our results indicate that orally administered treatment with either HDP-CDV or ODE-CDV is 4-8-fold more active, on a molar basis, than is intraperitoneally administered CDV. These data suggest that HDP-CDV and ODE-CDV should be further evaluated as potential antiviral agents for treatment of HCMV infection.     

MAL64 c is a global regulator of α-glucoside fermentation: identification of a new gene involved in melezitose fermentation

Summary Maltase constitutive mutants at the MAL6 locus have been mapped to the newly identified regulatory gene MAL64 ^c. We show here that MAL64 ^c has in addition pleiotropic effects on sugar fermentation: MAL64 ^c strains constitutively synthesize an -methylglucosidase and can complement a new gene, MTP1, for the fermentation of melezitose and -methylglucoside. MTP1, maps near MAL1, and either encodes a permease which transports melezitose, -methylglucoside, and maltose or regulates the activity of such a permease. This work shows that MAL64 ^c, a trans-acting regulatory gene, is a global regulatory gene affecting several different pathways of -glucoside metabolism.     

Ras gene product expression in blood and marrow smears of patients with acute leukemia: importance of fixation

Activation of ras protooncogenes by any of several possible mutations in codons 12, 13 or 61 has been demonstrated in a variety of human malignancies, including acute non-lymphoblastic leukemia (ANLL). In situ staining for the ras gene product, p21, has been demonstrated in carcinomas of several sites. High levels of p21 expression have been associated with histologic anaplasia in prostate cancer and regional lymph node metastasis in breast cancer. We examined 16 marrow aspirates and blood smears from patients with acute leukemia, predominantly ANLL, and eight controls. Marrow aspirates or blood were smeared on glass slides and fixed immediately in 10% buffered formalin. p21 was examined with avidin-biotin linked immunoperoxidase visualization. Particular attention must be paid to antibody selection and fixation protocol to demonstrate p21, owing to its rapid degradation ex vivo. Three of 16 patients exhibited occasional high p21 expression primarily in leukemic blasts, but in no case were more than 10% of blast cells positive. Normal reticuloendothelial and myeloid cells occasionally exhibited mild to moderately heavy staining, but megakaryocytes, erythroid precursors, lymphocytes and plasma cells were consistently negative. Most patients, 5 normal volunteers and 3 patients with non-malignant disease, exhibited no reactivity, or only a faint blush. These data suggest that while point mutation and concomitant activation of c-N-ras occurs regularly in ANLL, high levels of ras p21 expression are rarely found with this technique.     

Chondroitin sulfate proteoglycans in the developing cerebral cortex: The distribution of neurocan distinguishes forming afferent and efferent axonal pathways

The pharmacological and physiological properties of ligand-gated ion channels are dependent on their subunit composition; spontaneously occurring changes in subunit composition during neuronal development may result in dramatic functional differences between embryonic and adult forms of the receptor complex. In the present study, in situ hybridization with antisense cRNA probes was used to examine the subunit composition of the γ-aminobutyric acid_A/benzodiazepine (GABA_A/BZ) receptor in the developing inferior olivary complex. This receptor is thought to be a pentameric chloride channel comprised of selected α, β, γ, δ, and ρ subunits, the majority of which have several isoforms: α_1?6, β_1?4, γ_1?4 and ρ_{1, 2}. Among the 13 subunit variants present in the mammalian central nervous system, α_2?5 β₃, and γ_{1, 2} mRNAs are expressed at significant levels in the inferior olivary complex. Two clearly different temporal patterns of GABA_A/BZ receptor subunit mRNA expression were observed: The expression of α₃, α₅, β₃, and γ₂ mRNAs was at a peak during embryonic and early postnatal development followed by rapid down-regulation thereafter. Conversely, α₂, α₄, and γ₁ mRNA expression was very low or absent during early development, and a pronounced increase was observed at the end of postnatal week 1. These studies suggest that there are developmental changes in the subunit composition of the GABA_A/BZ receptor in inferior olivary neurons. These changes in subunit expression, which occur during a period of major alterations in afferent and efferent synaptic connections, may subserve a change in the role of GABA from its function as a neurotrophic factor to that of an inhibitory neurotransmitter. © 1995 Wiley-Liss, Inc.     

Impact of chemotherapy-induced neutropenia on quality of life: a prospective pilot investigation

Purpose In this exploratory, prospective study evaluated quality of life (QoL) changes in patients with diverse cancers during the first cycle of myelosuppressive chemotherapy.Patients and methods Of 80 patients enrolled, 71 were observed during one of five chemotherapy regimens: docetaxel; CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone); carboplatin-paclitaxel; carboplatin-docetaxel; and carboplatin-gemcitabine. Complete blood counts were taken weekly. QoL and symptom burden measures were administered at baseline and throughout the cycle, and included SF-36, Cancer Care Monitor (CCM), Hospital Anxiety and Depression Scale (HADS), and Psychosocial Adjustment to Illness Scale (PAIS). Using generalized estimating equations, we modeled the change in each measure from baseline to the end of each week using the following covariates: baseline QoL measure, baseline SF-36 Physical and Mental Health Summary scores, sex, age, cycle week, grade 4 neutropenia any time in the past 7 days (yes/no), and the interaction of the latter two covariates.Results Of the 71 patients observed, 33 developed grade 4 neutropenia during the first 2 weeks. Changes from baseline in SF-36 Bodily Pain, HADS Anxiety, and PAIS Social Environment scores were significantly less favorable (P<0.05) when patients experienced grade 4 neutropenia any time in the past 7 days compared to when they did not (grade 0–3). A similar, but non-significant, trend was also observed for 12 other QoL measures.Conclusion QoL may be adversely affected up to 7 days after patients experience grade 4 (versus grade 0–3) neutropenia. Such findings need to be examined further in studies with adequate statistical power to test a priori hypotheses regarding specific QoL measures.Support for this work was provided by Amgen Inc.Portions of the research were previously presented at: Mayo Clinic Assessing Clinical Significance for QoL Measures in Oncology Research, State-of-the-Science, March 2002, Rochester, MN; the 27th Meeting of the European Society of Medical Oncology, October 2002, Nice, France; and the American Society of Hematology, December 2002, Philadelphia, PA.     

Suppression of Plasmodium chabaudi parasitemia is independent of the action of reactive oxygen intermediates and/or nitric oxide

The killing of blood-stage malaria parasites in vivo has been attributed to reactive intermediates of oxygen (ROI) and of nitrogen (RNI). However, in the case of the latter, this contention is challenged by recent observations that parasitemia was not exacerbated in nitric oxide synthase (NOS) knockout (KO) (NOS2-/- or NOS3-/-) mice or in mice treated with NOS inhibitors. We now report that the time course shows that Plasmodium chabaudi parasitemia in NADPH oxidase KO (p47phox-/-) mice also was not exacerbated, suggesting a minimal role for ROI-mediated killing of blood-stage parasites. It is possible that the production of protective antibodies during malaria may mask the function of ROI and/or RNI. However, parasitemia in B-cell-deficient JH-/- x NOS2-/- or JH-/- x p47phox-/- mice was not exacerbated. In contrast, the magnitude of peak parasitemia was significantly enhanced in p47phox-/- mice treated with the xanthine oxidase inhibitor allopurinol, but the duration of patent parasitemia was not prolonged. Whereas the time course of parasitemia in NOS2-/- x p47phox-/- mice was nearly identical to that seen in normal control mice, allopurinol treatment of these double-KO mice also enhanced the magnitude of peak parasitemia. Thus, ROI generated via the xanthine oxidase pathway contribute to the control of ascending P. chabaudi parasitemia during acute malaria but alone are insufficient to suppress parasitemia to subpatent levels. Together, these results indicate that ROI or RNI can contribute to, but are not essential for, the suppression of parasitemia during blood-stage malaria.     

Long-term outcome of Hodgkin disease patients following high-dose busulfan, etoposide, cyclophosphamide, and autologous stem cell transplantation.

Busulfan (Bu)-based preparative regimens have not been extensively investigated in Hodgkin disease (HD). The purposes of this study were to investigate the toxicity and efficacy of a novel preparative regimen of Bu 14 mg/kg, etoposide 50-60 mg/kg, and cyclophosphamide 120 mg/kg in patients with primary refractory and relapsed HD. One hundred twenty-seven patients with a median age of 33 years (range, 14-67 years) underwent transplantation. The regimen was well tolerated, with 5.5% treatment-related mortality at 100 days after transplantation. With a median follow up of 6.7 years, the 5-year progression-free survival was 48 +/- 5%, and the 5-year overall survival was 51 +/- 5%. A Cox proportional hazards model identified refractory disease at time of transplantation as the only significant factor affecting relapse and overall survival, whereas disease bulk >10 cm affected overall survival. Five patients died between 5.3 and 9.3 years of late complications, including secondary myelodysplasia or acute myeloid leukemia, secondary solid malignancies, and pulmonary toxicity. This novel Bu regimen is comparable to other radiation-free preparative regimens in its effectiveness in the control of HD and with a low-risk of early treatment-related mortality.