Altered lipid parameters in hepatic subcellular membrane fractions induced by fumonisin B1

Alteration of lipid constituents of cellular membranes has been proposed as a possible mechanism for cancer promotion by fumonisin B(1 )(FB(1)). To further investigate this hypothesis a dietary dosage which initiates and promotes liver cancer (250 mg FB(1)/kg) was fed to male Fischer rats for 21 days and the lipid composition of plasma, microsomal, mitochondrial and nuclear subcellular fractions determined. The effect of FB(1) on the cholesterol, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), as well as sphingomyelin (SM) and the phospholipids-associated fatty acid (FA) profiles, were unique for each subcellular membrane fraction. PE was significantly increased in the microsomal, mitochondrial and plasma membrane fractions, whereas cholesterol was increased in both the microsomal and nuclear fraction. In addition SM was decreased and increased in the mitochondrial and nuclear fractions, respectively. The decreased PC/PE and polyunsaturated/saturated (P/S) FA ratio in the different membrane fractions suggest a more rigid membrane structure. The decreased levels in polyunsaturated fatty acids in PC together with a pronounced increase in C18:1omega9 and C18:2omega6 were indicative of an impaired delta-6 desaturase. The increased omega6/omega3 ratio and decreased C20:4omega6 PC/PE ratio due to an increase in C20:4omega6 in PE relatively to PC in the different subcellular fractions suggests a shift towards prostanoid synthesis of the E2 series. Changes in the PE and C20:4omega6 parameters in the plasma membrane could alter key growth regulatory and/or other cell receptors in lipid rafts known to be altered by FB(1). An interactive role between C20:4omega6 and ceramide in the mitochondria, is suggested to regulate the balance between proliferation and apoptosis in altered initiated hepatocytes resulting in their selective outgrowth during cancer promotion effected by FB(1).

Analysis of factors affecting development of carpal tunnel syndrome in patients with Hurler syndrome after hematopoietic cell transplantation

Children with Hurler syndrome (mucopolysaccharidosis type IH (MPSIH)) have skeletal, joint and soft tissue abnormalities that may persist or progress after hematopoietic stem cell transplantation (HSCT). We report our single center experience with development of carpal tunnel syndrome (CTS) in 43 children with MPSIH after HSCT. Twenty-three children (59%) developed CTS following HSCT; 19 of the 39 children with enzyme activity in the normal or heterozygous range developed CTS (49%), whereas all four children with low heterozygous or absent enzyme activity developed CTS after HSCT. Fourteen of 19 related donor marrow recipients, eight of 19 of those receiving an unrelated donor graft and one of five unrelated cord blood recipients developed CTS. The mean age at surgical release was 4.8 years. With each year increase in age at HSCT, there was a 55% increased risk. Age and enzyme activity after HSCT were significant factors in the development of CTS. Transplantation by 2 years of age reduced the risk of developing CTS by 46%; higher enzyme activity led to a 78% reduction in the risk of developing CTS. However, children transplanted for MPSIH remain at risk for the development of CTS, and should be monitored on an ongoing basis by nerve conduction velocity testing.

Long-term stability of a patient-convenient 1 mg/ml suspension of tacrolimus for accurate maintenance of stable therapeutic levels

Tacrolimus (Prograf, FK506, Fujisawa Healthcare) is a widely used immunosuppressive agent that is used both for the prevention and treatment of solid organ transplant rejection as well as for the prevention and treatment of graft-versus-host disease after allogeneic blood and marrow transplant. Oral preparations of tacrolimus are commercially available in 0.5, 1 and 5 mg gelatin capsules. Previously, only a 0.5 mg/ml oral suspension has been demonstrated to be stable for use in pediatric patients. On our bone marrow transplant service, we found that using this concentration of tacrolimus led to confusion, with patients and their caregivers confusing milligrams and milliliters, thus increasing errors with this formulation. We postulated that a 1 mg/ml oral formulation of tacrolimus would decrease the potential for medication errors. Our findings support new stability information of approximately 4 months for an extemporaneous oral suspension of tacrolimus at a concentration of 1 mg/ml.

Dietary modulation of fatty acid profiles and oxidative status of rat hepatocyte nodules: effect of different n-6/n-3 fatty acid ratios

Male Fischer rats were fed the AIN 76A diet containing varying n-6/n-3 FA ratios using sunflower oil (SFO), soybean oil (SOY), and SFO supplemented with EPA-50 and GLA-80 (GLA) as fat sources. Hepatocyte nodules, induced using diethylnitrosamine followed by 2-acetylaminofluorene/partial hepatectomy promotion, were harvested, with surrounding and respective dietary control tissues, 3 mon after partial hepatectomy. The altered growth pattern of hepatocyte nodules in rats fed SFO is associated with a distinct lipid pattern entailing an increased concentration of PE, resulting in increased levels of 20:4n-6. In addition, there is an accumulation of 18:1 n-9 and 18:2n-6 and a decrease in the end products of the n-3 metabolic pathway in PC, suggesting a dysfunctional delta-6-desaturase enzyme. The hepatocyte nodules of the SFO-fed rats exhibited a significantly reduced lipid peroxidation level that was associated with an increase in the glutathione (GSH) concentration. The low n-6/n-3 FA ratio diets significantly decreased 20:4n-6 in PC and PE phospholipid fractions with a concomitant increase in 20:5n-3, 22:5n-3, and 22:6n-3. The resultant changes in the 20:4/20:5 FA ratio and the 20:3n-6 FA level in the case of the GLA diet suggest a reduction of prostaglandin synthesis of the 2-series. The GLA diet also counteracted the increased level of 20:4n-6 in PE by equalizing the nodule/surrounding ratio. The low n-6/n-3 ratio diets significantly increased lipid peroxidation levels in hepatocyte nodules, mimicking the level in the surrounding and control tissue while GSH was decreased. An increase in n-3 FA levels and oxidative status resulted in a reduction in the number of glutathione-S-transferase positive foci in the liver of the GLA-fed rats. Modulation of cancer development with low n-6/n-3 ratio diets containing specific dietary FA could be a promising tool in cancer intervention in the liver.

Animal models and analytical approaches for understanding the relationships between wine and cancer

We used two approaches for studying the relationships between wine consumption, wine composition and cancer In the first approach, a transgenic mouse model of human neurofibromatosis, combined with the use of well-defined, chemically purified diets, showed that red wine contains nonalcoholic components that can delay tumor onset. In additional studies, catechin, the main monomeric polyphenol of red wine, delayed tumor onset in this mouse model in a positive, linear relationship when incorporated into the diet at levels of 0.5-4 mmol/kg diet. In the second approach, low doses of the chemical carcinogen 2-amino-1-methyl-6-phenylimidazo(4, 5-b)pyridine (PhlP) were administered to rats, and formation of DNA adducts was evaluated by accelerator mass spectrometry. Consumption of red wine solids (the residue from red wine remaining after removal of alcohol and water) and the wine polyphenol quercetin did not influence PhlP-DNA adduct levels or induce liver enzymes (glutathione-S-transferase and quinone reductase). However, quercetin did alter distribution of PhlP in the rat tissues compared to control animals and animals fed other potential dietary chemopreventive agents, including phenylethyl isothiocyanate and sulforaphane. These studies demonstrate the feasibility of these approaches for studying the chemopreventive potential of dietary components at physiologic levels in

Availability of unrelated donors for hematopoietic stem cell transplantation for hemoglobinopathies

Hematopoietic stem cell transplantation (HSCT) is the only curative option for patients with hemoglobinopathies. However, fewer than 30% of individuals will have an HLA-identical sibling. Improvement in outcomes after HSCT using unrelated donors (URD), and the development of novel nontoxic preparative regimens may make URD HSCT an option for hemoglobinopathy patients who do not have an HLA-identical sibling donor. The National Marrow Donor Program (NMDP) maintains a Registry of 4 million volunteer donors, and facilitates URD HSCT for patients with life-threatening blood diseases. In light of the increased representation of minorities in the NMDP registry, donor searches were run in April 2001 for a cohort of 272 thalassemia patients and 77 sickle cell disease (SCD) patients for whom searches had been submitted between 1989 and 2001 in order to determine the current likelihood of finding a potential donor of hematopoietic stem cells for hemoglobinopathy patients. About 59.7% SCD patients 80.2% thalassemia patients will find at least one potential 6/6 HLA matched donor or umbilical cord blood (UCB) unit. All patients will find at least one donor or UCB that is a potential 5/6 HLA match. In conclusion the majority of hemoglobinopathy patients will find at least one potential HLA matched unrelated bone marrow donor or UCB.

Additional stringy sources for electric dipole moments

We show that string models with low energy supersymmetry which accommodate the fermion mass hierarchy generally give nonuniversal soft trilinear couplings (A terms). In conjunction with the apparently large Cabibbo-Kobayashi-Maskawa (CKM) phase, this results in large fermion electric dipole moments (EDMs) even in the absence of CP violating phases in the supersymmetry breaking auxiliary fields and the micro term. Nonobservation of the EDMs therefore implies that strings select special flavor and/or supersymmetry breaking patterns.

Lipids and delta6-desaturase activity alterations in rat liver microsomal membranes induced by fumonisin B1

Alterations in the membrane structure and function of hepatocyte membranes by fumonisin B1 (FB1) have been proposed to play an important role in the disruption of growth regulatory effects and hence in the cancer-promoting ability of the mycotoxin. Detailed analyses of lipids in liver microsomal fractions of rats exposed to different dietary levels of FB1 over a period of 21 d indicated an increase in PC, PE, PI, and cholesterol (Chol). These changes decreased the PC/PE and increased the total phospholipid/Chol ratios. When considering FA content, the quantities of total FA increased (P < 0.05) in the major phospholipid fractions as a result of the increased phospholipid levels. However, when considering the relative levels (mg/100 mg of the total FA) of specific FA, the monounsaturated FA (16:1 n-7 and 18:1n-9) and 18:2n-6 increased (P < 0.05), whereas the long-chain PUFA decreased (P < 0.05) in the main phospholipid fractions. Enzyme analyses indicated that the activity of the delta6-desaturase was significantly reduced in liver microsomal preparations in a dose-dependent manner. An increase in the 20:3n-6/20:4n-6 ratio also suggested a decrease in the activity of the delta5-desaturase. Disruption of microsomal lipid metabolism at different levels by FB1 could play an important role in the alteration of growth regulatory effects in the liver.

Attenuation of phosphate starvation responses by phosphite in Arabidopsis

When inorganic phosphate is limiting, Arabidopsis has the facultative ability to metabolize exogenous nucleic acid substrates, which we utilized previously to identify insensitive phosphate starvation response mutants in a conditional genetic screen. In this study, we examined the effect of the phosphate analog, phosphite (Phi), on molecular and morphological responses to phosphate starvation. Phi significantly inhibited plant growth on phosphate-sufficient (2 mM) and nucleic acid-containing (2 mM phosphorus) media at concentrations higher than 2.5 mM. However, with respect to suppressing typical responses to phosphate limitation, Phi effects were very similar to those of phosphate. Phosphate starvation responses, which we examined and found to be almost identically affected by both anions, included changes in: (a) the root-to-shoot ratio; (b) root hair formation; (c) anthocyanin accumulation; (d) the activities of phosphate starvation-inducible nucleolytic enzymes, including ribonuclease, phosphodiesterase, and acid phosphatase; and (e) steady-state mRNA levels of phosphate starvation-inducible genes. It is important that induction of primary auxin response genes by indole-3-acetic acid in the presence of growth-inhibitory Phi concentrations suggests that Phi selectively inhibits phosphate starvation responses. Thus, the use of Phi may allow further dissection of phosphate signaling by genetic selection for constitutive phosphate starvation response mutants on media containing organophosphates as the only source of phosphorus.

Infant care practices in New Zealand: a cross-cultural qualitative study

This paper describes and compares the infant care practices and beliefs of Maori, Tongan, Samoan, Cook Islands, Niuean and Pakeha (European) caregivers residing in Auckland, New Zealand. Focusing on four areas--sources of support and advice; infant feeding; infant sleeping arrangements; and traditional practices and beliefs--it explores inter-ethnic similarities and differences and intra-ethnic tensions. The international literature indicates that there can be significant cultural variation in infant care practices and in the meanings attributed to them. There is, however, little New Zealand literature on this topic, despite its importance for effective health service and health message delivery. Participants were primary caregivers of infants under 12 months. An average of six focus groups were conducted within each ethnic group, resulting in a total of 37 groups comprising 150 participants. We found similarities across all ethnic groups in the perceived importance of breastfeeding and the difficulties experienced in establishing and maintaining this practice. The spectrum of behaviours ranged widely with differences most pronounced between Pacific caregivers, especially those Island-raised, and Pakeha caregivers, especially those in nuclear families. Amongst the former, norms included: the family as central in providing support and advice; infant bedsharing; abdominal rubbing during pregnancy; baby massage; and the importance of adhering to traditional protocols to ensure infant well-being. Amongst the latter, norms included: strong reliance on professional advice; looser family support networks; the infant sleeping in a cot; and adherence to Western biomedical understandings of health and illness. Maori caregivers bridged the spectrum created by these groups and exhibited a diverse range of practices. Intra-cultural differences were present in all groups indicating the dynamic nature of cultural practices. They were most evident between Pacific-raised and New Zealand-raised Pacific caregivers, with the latter attempting to marry traditional with Western beliefs and practices.

Cancer initiation by fumonisin B(1) in rat liver--role of cell proliferation

Fumonisin B(1) (FB(1)), a carcinogenic mycotoxin produced by the fungus Fusarium verticillioides in corn, causes cancer initiation in rat liver in a similar manner to genotoxic carcinogens although apparently with different kinetics. The present experiment was designed to evaluate the role of regenerative cell proliferation, effected by partial hepatectomy (PH) and carbontetrachloride (CCl(4)) and direct mitogen-induced hyperplasia, induced by lead nitrate (PbNO(3)), on FB(1)-induced cancer initiation. Initiation was effected over a period of 14 days by gavage administration of FB(1) at different daily doses ranging from 0.14 to 3.5 mg FB(1)/100 g body weight while the stimuli for cell proliferation were introduced 7 days after the start of the FB(1) treatment. Based on the proliferative stimulus used, cancer promotion was effected 3 weeks after completion of the initiating treatment by 2-acetylaminofluorene (2-AAF) treatment followed by PH or carbon tetrachloride CCl(4) on day 4. Cancer initiation by FB(1) was associated with a hepatotoxic effect and an increase in lipid peroxidation. In contrast to compensatory liver cell proliferation induced by PH and CCl(4), mitogen-induced hyperplasia (PbNO(3)) failed to enhance the cancer initiating potential of FB(1) suggesting that cancer induction by a non-genotoxic carcinogen is supported by regenerative cell proliferation. Cognizance of the enhancing role of cell proliferation during cancer initiation by FB(1) is required in assessing the risks posed by this mycotoxin to humans.

Potential role for P-glycoprotein in the non-proportional pharmacokinetics of UK-343,664 in man

1. UK-343,664 is a potent and specific PDE5 inhibitor. Following single oral doses to human volunteers, it exhibited non-proportional pharmacokinetics over the dose range 30-800 mg. Over this 27-fold dose range, Cmax and AUCt increased 247- and 287-fold respectively. The half-life (4-6 h) was similar at all doses. No systemic exposure was quantifiable at doses <10 mg. 2. UK-343,664 is a lipophilic molecule (log D7.4 = 3.1) and as such is expected to be cleared mainly by metabolism. Based on studies with expressed human P450 enzymes it was concluded that the metabolism of UK-343,664 was predominantly mediated by CYP3A4. With a moderate Km = 76 microM for this enzyme, saturation of first-pass metabolism alone was considered unlikely to account for the non-proportional pharmacokinetics. 3. UK-343,664 showed high affinity for P-glycoprotein in vitro, with a Km = 7.3 microM. In transport studies in LLC-PK1 cell monolayers transfected with P-glycoprotein, UK343,664 showed marked polarized transport which was concentration dependent. 4. The high affinity of UK-343,664 for P-glycoprotein is considered to be the primary source of the non-proportional pharmacokinetic profile observed in man.

Efficacy of a polyvalent bacterial lysate in children with recurrent respiratory tract infections

Respiratory tract infections (RTIs) are the most frequent infections in humans, particularly in children. In addition to intervention, increasing interest is focusing on immunomodulatory therapy for recurrent RTIs, which indicate a reduced defense capacity of the respiratory mucosa. LW 50020, an oral immunomodulator that contains the antigens of seven bacteria common in RTIs, has reduced the number, duration, and severity of RTIs in children and adults. This 56-week placebo-controlled, double-blind study in 188 children investigated whether the efficacy of the standard schedule (immunization cycle + one booster cycle) would be enhanced by additional booster cycles. Efficacy and safety over the long term were also assessed. The rate of infection was reduced by 50% with the standard schedule and could not be further decreased by two consecutive booster cycles. With both schedules, this reduction was sustained during a 28-week treatment-free observation period that followed the 28-week treatment period. The number of adverse drug reactions was low, and all were transient, expected, and nonserious. These results confirm that LW 50020 is an effective and safe strategy for RTIs.

Electric dipole moment cancellations in D-brane models

We analyze the possibility of simultaneous electron, neutron, and mercury electric dipole moment (EDM) cancellations in the mSUGRA and D-brane models. We find that the mercury EDM constraint practically rules out the cancellation scenario in D-brane models, whereas in the context of mSUGRA it is still allowed with some fine tuning.

Quantification of HTLV type I and HIV type I DNA load in coinfected patients: HIV type 1 infection does not alter HTLV type I proviral amount in the peripheral blood compartment

Several reports suggest that HTLV-I/HIV coinfection may be associated with an increased risk of HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). In HTLV-I-monoinfected patients, the occurrence of HAM/TSP is associated with high peripheral blood HTLV-I proviral load. Using a real-time quantitative PCR assay, we assessed the proviral DNA load in peripheral blood mononuclear cells (PBMCs) from 15 asymptomatic HTLV-I-monoinfected patients, 15 HTLV-I-monoinfected patients with HAM/TSP, and 25 HTLV-I/HIV-1 coinfected patients, including 4 with HAM/TSP. We also measured HIV-1 proviral DNA load in PBMCs from the coinfected patients. The median HTLV-I proviral loads were 6,800 and 4,100 copies per 10(6) PBMCs in the asymptomatic monoinfected and coinfected groups, and 58,800 and 43,300 copies per 10(6) PBMCs in the monoinfected and coinfected patients with HAM/TSP, respectively. The difference between HTLV-I proviral loads in HAM/TSP and asymptomatic monoinfected patients was statistically significant (p < 0.0001), but there was no difference between the HTLV-I-monoinfected and HTLV-I/HIV-1-coinfected groups. There was no correlation between HTLV-I and HIV-1 proviral load. HTLV-I proviral load did not correlate with the CD4+ T lymphocyte count. Among patients with no HTLV-I disease, the median copy number of HTLV-I per 10(6) circulating CD4+ T cells was 114,000 in the coinfected group and 16,700 in the monoinfected group, but the difference was not significant (p = 0.089). These data do not confirm the hypothesis in which HIV-1 coinfection would increase HTLV-I proviral burden in the PBMCs. However, depletion of the CD4+ T cell subset, the main target of HTLV-I, could be counterbalanced by an up-regulation of HTLV-I replication or by greater resistance of HTLV-I-infected cells to HIV-1-induced destruction.