In vitro effects of lapachol and β-lapachone against Leishmania amazonensis

Leishmaniasis is a neglected disease that affects millions of people worldwide, and special attention should be given to treatment because the available drugs have limitations, which can lead to low therapeutic adherence and parasitic resistance. This study evaluated the activity of the bioactive naphthoquinones, lapachol and β-lapachone, against Leishmania amazonensis. The cell alterations were evaluated in vitro on promastigote and amastigote forms. The lethal dose (LD50) at 24, 48, and 72 h on the promastigote's forms using lapachol was 75.60, 72.82, and 58.85 μg/mL and for β-lapachone was 0.65, 1.24, and 0.71 μg/mL, respectively. The naphthoquinones significantly inhibited the survival rate of L. amazonensis amastigotes at 83.11, 57.59, and 34.95% for lapachol (82.28, 41.14, and 20.57 µg/mL), and 78.49, 83.25, and 80.22% for β-lapachone (3.26, 1.63, and 0.815 µg/mL). The compounds on the promastigote's forms led to the loss of mitochondrial membrane potential, induced changes in the integrity of the membrane, caused damage to cells suggestive of the apoptotic process, and showed inhibition of tumor necrosis factor (TNF)-α and interleukin (IL)-6 production. The results showed that these naphthoquinones are promising candidates for research on new drugs with anti-Leishmania activity derived from natural products.

Influence of CYP2D6, CYP3A4 and CYP2C19 Genotypes on Recurrence of Plasmodium vivax

Background

The influence of the CYPs (cytochrome P-450) in the success of antimalarial therapy remains uncertain. In this study, the association of CYP2D6, CYP2C19 and CYP3A4 polymorphisms and predicted phenotypes with malaria recurrence was investigated.

Methods

After diagnosis of vivax malaria, individuals treated at a reference center in Manaus were followed up for 180 days. Patients were separated into two groups: a recurrence group and a non-recurrence group. Genotyping of CYP2D6, CYP2C19 and CYP3A4 was performed using a TaqMan™ assay and real-time PCR.

Findings

The frequencies of decreased-function and normal-function alleles and phenotypes for all CYPs were similar between the groups, except for the CYP2D6*2xN allele (p=0.047) and the CYP2D6 gUM phenotype (p=0.057), which were more frequent in individuals without recurrence. Despite this, the CYP2D6, CYP2C19 and CYP3A4 genotypes had no association with an increased risk of recurrence. CYPs polymorphisms also had no influence in parasite clearance, neither in the time nor the number of recurrence episodes. MAIN

Conclusion

This prospective cohort study demonstrated that CYP2D6, CYP2C19 and CYP3A4 polymorphisms have no influence on malaria recurrence. Nonetheless, our findings suggest that the CYP2D6 predicted ultrarapid phenotype was less susceptible to recurrence, and that patients with the CYP2D6 gUM phenotype are less susceptible to primaquine failure. Additional investigation of pharmacogenetics and pharmacokinetics are needed before implementing CYP analysis to better orientate individualized radical treatment of vivax malaria in reference centers that treat patients with multiple recurrences.

IMPACTO NA DEMANDA DOS PROCEDIMENTOS DA RECUPERAÇÃO INTRAOPERATÓRIA DE SANGUE DURANTE A PANDEMIA DA COVID-19

Introdução

A recuperação intraoperatória de sangue (RIOS) é a prática de transfusão autóloga destinada a recuperar sangue que seria perdido durante cirurgias de médio e grande porte.Sendo as cirurgias cardíacas, vasculares, ortopédicas e transplantes de órgãos sólidos contempladas com este serviço. Com a pandemia da Covid-19 o serviço sofreu um impacto diante do número de procedimentos, onde a quantidade de cirurgias foram afetadas, principalmente por não haver vagas em unidades de terapia intensiva no pós-operatório, vale ressaltar a exposição da equipe nos hospitais que continuam operando mesmo em menor fluxo e atendendo pacientes infectados pela covid.

Objetivo

Comparar a demanda dos procedimentos da Rios durante a pandemia da Covid-19 em relação a utilização em anos anteriores.

Método

Trata-se de um estudo descritivo analítico em formato de relato de experiência, vivenciado pela equipe composta por enfermeiras em regime de sobreaviso em um serviço de hemoterapia, disponível 24h por dia no Centro de Hematologia e Hemoterapia do estado do Ceará. Usando dados no período de 2018 a junho de 2021.

Resultados

Após analisar o número de procedimentos realizados nos anos anteriores a pandemia, identificou-se uma redução na utilização do serviço. Em 2018 foram 1.029 procedimentos, 2019 1.237 procedimentos, 2020 foram 942 procedimentos e 2021 foram 395 procedimentos até junho. Observamos que houve um crescimento de 23 % entre 2018 e 2019, pois houve a conscientização dos profissionais em relação a importância do serviço para os pacientes, no intuito de minimizar os riscos da transfusão sanguínea, e a redução veio em 2020 com o início da pandemia, devido a restrição de cirurgias eletivas, transplantes, equipes e o acesso e disponibilidade aos leitos de terapia intensiva.

Considerações finais

A atuação da RIOS é de importância, pois minimiza os riscos transfusionais para os pacientes ao diminuir a quantidade de transfusão alogênica, diante o cenário atual da pandemia da Covid-19, o serviço sofreu uma redução considerável de procedimentos.

Real-life implementation of a G6PD deficiency screening qualitative test into routine vivax malaria diagnostic units in the Brazilian Amazon (SAFEPRIM study)

Background

Glucose-6-phosphate dehydrogenase (G6PD) deficiency greatly hinders Plasmodium vivax malaria radical cure and further elimination due to 8-aminoquinolines-associated hemolysis. Although the deleterious health effects of primaquine in G6PD deficient individuals have been known for over 50 years, G6PD testing is not routinely performed before primaquine treatment in most P. vivax endemic areas.

Method/Principal findings

The qualitative CareStart G6PD screening test was implemented in 12 malaria treatment units (MTUs) in the municipality of Rio Preto da Eva, Western Brazilian Amazon, a malaria endemic area, between February 2019 and early January 2020. Training materials were developed and validated; evaluations were conducted on the effectiveness of training health care professionals (HCPs) to perform the test, the interpretation and reliability of routine testing performed by HCPs, and perceptions of HCPs and patients. Most HCPs were unaware of G6PD deficiency and primaquine-related adverse effects. Most of 110 HCPs trained (86/110, 78%) were able to correctly perform the G6PD test after a single 4-hour training session. The test performed by HCPs during implementation showed 100.0% (4/4) sensitivity and 68.1% (62/91) specificity in identifying G6PD deficient patients as compared to a point-of-care quantitative test (Standard G6PD).

Conclusions/Significance

G6PD screening using the qualitative CareStart G6PD test performed by HCPs in MTUs of an endemic area showed high sensitivity and concerning low specificity. The amount of false G6PD deficiency detected led to substantial loss of opportunities for radical cure.

Glucose 6-phosphate dehydrogenase deficiency (G6PDd) has greatly impacted the treatment of Plasmodium vivax malaria because of the red blood cell destruction in what is known as hemolysis. Primaquine, used to clear dormant liver parasites that cause relapses of the disease, is a well-known trigger that may lead to life-threatening complications in patients with this condition. Although there are several G6PDd diagnostic tests available to guide the decision of weekly or daily primaquine treatment, they are not yet routinely used: questions on how, when, where and who is going to perform the test remain unanswered. This study revealed that, although G6PDd was not previously known by most of the healthcare workers, they were able to perform the test after a single training session. The test performed well in the field, differentiating patients that cannot use daily primaquine from the others, but some expected limitations require further action to be taken into consideration. This research provides an important overall understanding that may aid policy makers in the process of recommending proven interventions, such as G6PDd screening, to implement them pragmatically.

Combined effects of caloric restriction and fish oil attenuated anti-depressant and anxiolytic-like effects of fish oil: association with hippocampal BDNF concentrations

Omega-3-enriched fish oil (FO) and caloric restriction (CR) are nutritional therapeutic approaches that exert an important impact on brain function, behavior, memory, and neuroprotection. Here, we investigate the synergic effects of both therapeutic approaches combined (CR + FO) on behavior (memory, anxiety-like behavior, antidepressant-like behavior), as well as its association with hippocampal brain-derived neurotrophic factor (BDNF) concentrations. Adult male Wistar rats were divided into four dietary groups: Control group (C) - chow ad libitum; CR group - 30 % CR, considering C group food intake; FO group - FO-enriched chow ad libitum; and CR + FO group - FO-enriched 30 % CR chow. After 12 weeks of dietary treatment, behavioural analysis set was conducted, and hippocampal BDNF concentrations were measured. FO group presented anxiolytic-like and antidepressant-like behaviors as well as improved memory in the Morris' water maze. These effects were attenuated by the combined CR + FO treatment. FO group also presented higher BDNF concentrations. There was a positive association between the number of entries in the platform quadrant in the MWM and hippocampal BDNF concentrations (β = 0.39; R² = 0.15; p = 0.042) and an inverse association between forced swim immobility time and BDNF concentrations (β = -0.39; R² = 0.15; p = 0.041). Taken together, our data showed that the 12-week FO dietary treatment promoted anxiolytic-like and antidepressant-like behaviors as well as memory improvement, and these effects were associated with BDNF concentrations. Synergic effects of interventions attenuated FO-related behavioral responses and BDNF concentrations and probably reduced hippocampal neuroplasticity.

The comparative advantages of ethanol and sucrose as co-substrates in the degradation of an anionic surfactant: microbial community selection

The efficiency of linear alkylbenzene sulfonate (LAS) removal from laundry wastewater and the related microbial community was investigated in an anaerobic fluidized bed reactor (AFBR). The AFBR was operated in three stages, in addition to the biomass adaptation stage without LAS (stage I). The stages were differentiated by their supplementary co-substrates: stage II had sucrose plus ethanol, stage III had only ethanol, and stage IV had no co-substrate. The replacement of sucrose plus ethanol with ethanol only for the substrate composition favored the efficiency of LAS removal, which remained high after the co-substrate was removed (stage II: 52 %; stage III: 73 %; stage IV: 77 %). A transition in the microbial community from Comamonadaceae to Rhodocyclaceae in conjunction with the co-substrate variation was observed using ion sequencing analysis. The microbial community that developed in response to an ethanol-only co-substrate improved LAS degradation more than the community that developed in response to a mixture of sucrose and ethanol, suggesting that ethanol is a better option for enriching an LAS-degrading microbial community.

Novel electrochemical method of fast and reproducible fabrication of metallic nanoelectrodes

A novel electrochemical wire etching method of fabrication of ultrasharp nanoelectrodes is reported. Tungsten wires can be sharpened to less than 10 nm tip radius in a reproducible manner in less than 1 min by using controllable hydrodynamic electrolyte flow combined with optimized electrochemical etching parameters. The method relies on the variations of the electric field at the surface of a metal wire, while the electrolyte solution is in motion, rather than on the ionic gradient generated in a static solution.

Electronic structure of Zn, Cu and Ni impurities in germanium

We present a density functional modelling study of Zn, Cu and Ni impurities in hydrogen-terminated germanium clusters. Their electronic structure is investigated in detail, especially their Jahn-Teller instabilities and electrical levels. Interstitial and substitutional defects were considered and the latter were found to be the most stable defect form for nearly all Fermi level positions. Relative formation energies are estimated semi-empirically with the help of the measured formation energy of the single Ge vacancy. We find that while Zn is a double shallow acceptor, Cu and Ni are deep acceptors with levels close to the available experimental data. Donor levels were only found for interstitial Cu and Zn.

Magnetic Carriers: A Promising Device for Targeting Drugs Into the Human Body

Suboptimal disposition behavior of drugs requires innovative delivery approaches. Magnetic drug targeting seems to be a promising one. Magnetic particles develop magnetic polarization and magnetophoretic mobility, and because of such unique properties, these carriers may be eligible candidates for delivering drugs to specific locations within the body. Their special properties also allow other uses, such as those in magnetic separation, hyperthermia, and magnetic resonance imaging. This review focuses on a brief discussion of magnetic drug targeting, the properties and fate of magnetic carriers, the methods used to produce and characterize them, and their other uses in biotechnology.

Chagas' disease susceptibility/resistance: linkage disequilibrium analysis suggests epistasis between major histocompatibility complex and interleukin-10

Association between the major histocompatibility complex (MHC) and the susceptibility/resistance to acquire Chagas' disease has been largely demonstrated. To study the role of candidate genes in this susceptibility/resistance to Chagas, we designed a population-genetic-based case-control approach (chagasic n = 104 and controls n = 60) and tested the presence of genotype and linkage disequilibrium on microsatellite loci establishing specific landmarks for the MHC, interleukin (IL)-2, IL-2Rbeta chain, IL-4, IL-10, and natural resistance-associated mactophage protein 1 (NRAMP1). After demonstrating no genetic stratification among cases and controls (F(st) were not different from 0), we found significant allelic differences among chagasic patients and controls at microsatellite locus D6S291 (MHC) and at the microsatellite pointing out the IL-10. At the MHC, we found significant differences between patients and controls in Hardy-Weinberg equilibrium-expected genotype proportions. Additionally, MHC II-locus-inferred haplotypes in chagasic patients exhibited strong significant departures from the expected proportions predicted by the second Mendelian law. The linkage disequilibrium pattern at MHC involves a region of approximately 10 cM. These results replicate previous analyses and suggest that presence of epistasis between MHC with humoral systems, such as IL-10, could be underlying the susceptibility/resistance to Chagas' disease.

Plasma kinetics of a cholesterol-rich emulsion in young, middle-aged, and elderly subjects

Low density lipoprotein (LDL) plasma concentration is increased in the elderly. In this group, the incidence of coronary artery disease (CAD) is greater and LDL remains an important risk factor for CAD development. In this study, the plasma kinetics of a cholesterol-rich emulsion that binds to LDL receptors was studied in 10-subject groups of the elderly (70 +/- 4 yr), middle-aged (42 +/- 5 yr) and young (23 +/- 2 yr). All were normolipidemic, nonobese, nondiabetic subjects who did not have CAD. The emulsion was labeled with 14C-cholesteryl oleate and injected intravenously into the subjects. Blood samples were drawn at regular intervals over 24 h to determine the plasma decay curve of the emulsion radioactive label and to estimate its plasma fractional clearance rate (FCR, in h(-1)). FCR of the emulsion label was smaller in elderly compared to young subjects (0.032 +/- 0.035 and 0.071 +/- 0.049 h(-1), respectively; mean +/- SD, P< 0.05). FCR of the middle-aged subjects (0.050 +/- 0.071 h(-1)) was intermediate between the values of the elderly and young subjects, although not statistically different from them. A negative correlation was found betweeen the emulsion FCR and subjects' age (r = -0.47, P = 0.008). We conclude that aging is accompanied by progressively diminished clearance of the emulsion cholesterol esters and, by analogy, of the native LDL.

Peroxynitrite-modified 99mTc-beta-VLDL: tissue distribution and plasma clearance rate

Free radicals superoxide (O(2)(-)) and nitric oxide (*NO) are generated by blood vessels and can rapidly react to produce a peroxynitrite anion (ONOO(-)), a powerful oxidant that modifies lipoproteins making them more atherogenic. The aim of this study was to investigate the effect of peroxynitrite-induced modifications on beta-very-low-density lipoprotein (beta-VLDL) as to its biodistribution and plasma clearance rate, as well as the uptake of these particles by THP-1 cells. After being injected into New Zealand White rabbits, the peroxynitrite-modified beta-VLDL (99mTc-per-beta-VLDL) was cleared from circulation faster than the native beta-VLDL (99mTc-nat-beta-VLDL) in both normocholesterolemic rabbits (NC) and in hypercholesterolemic rabbits (HC). In HC rabbits, the fractional clearance of 99mTc-labeled beta-VLDL was significantly lower than in NC rabbits. The in vivo studies showed that accumulation of 99mTc-labeled beta-VLDL, expressed per gram of tissue, followed the decreasing order: kidney > liver > spleen > adrenal gland >or= lung > aortic arch > heart >or= abdominal aorta > thoracic aorta > psoas muscle. The high accumulation in the kidneys suggests the processing of 99mTc-labeled apolipoproteins by receptors present in kidney cells. The accumulation of 99mTc-nat-beta-VLDL in the whole organ was the following: liver > kidney > heart > spleen > adrenal gland > aorta in HC and NC rabbits. The uptake of 99mTc-per-beta-VLDL by the spleen was greater than the uptake by the heart in both groups. The in vitro studies showed that the uptake of 99mTc-per-beta-VLDL by THP-1 cells was higher than that of 99mTc-nat-beta-VLDL. These results show that peroxynitrite-modified beta-VLDL is rapidly removed from plasma and accumulates in several tissues, mainly in the liver and kidney. This may be particularly important in hypercholesterolemic situations that could favor the accumulation of native and peroxynitrite-modified beta-VLDL in several tissues.

[Cardiac neuronal depopulation in hamsters (Mesocricetus auratus) chronically infected with Trypanosoma cruzi]

The aim of this study was to obtain an experimental animal model of destruction of cardiac neurons in order to investigate the behavior of the cardiac nervous system of hamsters chronically infected with Trypanosoma cruzi. We counted the neuronal cells of the cardiac autonomic nervous plexus in hamsters inoculated with 35,000 blood forms of three different T. cruzi strains and killed 5, 8 and 10 months after infection. We showed for the first time severe neuronal destruction in an experimental animal model with characteristics similar to those observed in human Chagas'disease.

[First evidence of Trypanosoma rangeli in the southeast of Brazil, an endemic region for Chagas' disease]

This short communication informs the discovery of Trypanosoma rangeli for the first time at Triângulo Mineiro region, South-east of Brazil, a highly endemic area of Chagas' disease and also the natural infection of Didelphis albiventris with the same trypanosome. Both the findings were demonstrated through blood smears, xenodiagnosis, microhematocrit technics and PCR. The last one was realized in faeces and hemolymph of Triatoma infestans utilizing as controls strains of T. rangeli from Colombia.

Plasma clearance and biodistribution of oxidatively modified 99mTc-beta-VLDL in rabbits

The biodistribution and removal from plasma (measured as fractional clearance rate, FCR, per hour) of native and oxidatively modified 99mtechnetium-labeled beta-very low density lipoprotein (99mTc-beta-VLDL) were investigated in hypercholesterolemic (HC) and control (C) three-month old New Zealand rabbits. The intracellular accumulation of beta-VLDL labeled with 99mTc was studied in vitro in THP-1 cells and monocyte-derived macrophages isolated from rabbits. After intravenous injection into C rabbits, copper-oxidized beta-VLDL (99mTc-ox-beta-VLDL) was cleared from the circulation faster (0.362 +/- 0.070/h) than native beta-VLDL (99mTc-nat-beta-VLDL, 0.241 +/- 0.070/h). In contrast, the FCR of 99mTc-ox-beta-VLDL in HC rabbits was lower (0.100 +/- 0.048/h) than that of 99mTc-nat-beta-VLDL (0.163 +/- 0.043/h). The hepatic uptake of radiolabeled lipoproteins was lower in HC rabbits (0.114 +/- 0.071% injected dose/g tissue for 99mTc-nat-beta-VLDL and 0.116 +/- 0.057% injected dose/g tissue for 99mTc-ox-beta-VLDL) than in C rabbits (0.301 +/- 0.113% injected dose/g tissue for 99mTc-nat-beta-VLDL and 0.305 +/- 0.149% injected dose/g tissue for 99mTc-ox-beta-VLDL). The uptake of 99mTc-nat-beta-VLDL and 99mTc-ox-beta-VLDL by atherosclerotic aorta lesions isolated from HC rabbits (99mTc-nat-beta-VLDL: 0.033 +/- 0.012% injected dose/g tissue and 99mTc-ox-beta-VLDL: 0.039 +/- 0.017% injected dose/g tissue) was higher in comparison to that of non-atherosclerotic aortas from C rabbits (99mTc-nat-beta-VLDL: 0.023 +/- 0.010% injected dose/g tissue and 99mTc-ox-beta-VLDL: 0.019 +/- 0.010% injected dose/g tissue). However, 99mTc-nat-beta-VLDL and 99mTc-ox-beta-VLDL were taken up by atherosclerotic lesions at similar rates. In vitro studies showed that both monocyte-derived macrophages isolated from rabbits and THP-1 macrophages significantly internalized more 99mTc-ox-beta-VLDL than 99mTc-nat-beta-VLDL. These results indicate that in cholesterol-fed rabbits 99mTc-ox-beta-VLDL is slowly cleared from plasma and accumulates in atherosclerotic lesions. However, although the extent of in vitro uptake of 99mTc-ox-beta-VLDL by macrophages was high, the in vivo accumulation of this radiolabeled lipoprotein by atherosclerotic lesions did not differ from that of 99mTc-nat-beta-VLDL.

Antibody response after immunization of Brazilian children with serogroup C meningococcal polysaccharide noncovalently complexed with outer membrane proteins

We have studied the antibody response of Brazilian vaccinees to C meningococcal polysaccharide (C-PS) after one or two doses of a vaccine composed of C-PS, outer membrane proteins of B meningococci and aluminum hydroxide. Total IgG, IgG1 and IgG2 as well as bactericidal activity mediated by complement were measured in serum samples from children 3 to 83 months of age (post-vaccination IgG, IgG1 and IgG2 levels of 2.4 to 13.4 micrograms/ml; less than 18 to 67.8 U/ml and less than 18 to 106.8 U/ml, respectively) and from individuals 10 to 14 years of age (post-vaccination IgG, IgG1 and IgG2 levels of 14.6 micrograms/ml, 23.7 U/ml and 112.0 U/ml, respectively). The antibody response, measured as IgG levels, was age-dependent. Although high antibody levels were demonstrable by enzyme-linked immunosorbent assay (ELISA), bactericidal activity was not demonstrable (less than 1:4) in serum from children aged less than 24 months. A significant bactericidal activity was detected in serum of children older than 49 months of age and in individuals 10 to 14 years of age. A predominance of IgG2 was observed in post-vaccination serum samples from children belonging to those two age groups. The antibody concentration sufficient to confer protection as well as the possible causes of the poor correlation observed between ELISA and bactericidal activity results are discussed.

Plasma antioxidant enzymes and oxidized lipoproteins in hypercholesterolemic rabbits

The activities of superoxide dismutase (SOD, EC 1.15.1.1), glutathione peroxidase (GPx, EC 1.11.1.9) and the levels of alpha-tocopherol and oxidized lipoproteins were investigated in the plasma of New Zealand rabbits either before or after cholesterol-diet induced hypercholesterolemia. Plasma SOD activity increased while GPx activity decreased after 60 days of cholesterol feeding. However, in the cholesterol-fed rabbits the release of superoxide dismutase fraction C from vasculature by heparin was lower than that in control rabbits. The levels of triglyceride hydroperoxides increased in low density and high density lipoproteins after feeding rabbits with the cholesterol-rich diet during 60 days. Also, a trend for increasing cholesteryl ester hydroperoxides was observed in beta-very low density and high density lipoproteins. An increase in alpha-tocopherol concentration (microM) was observed in very low density and low density lipoprotein fractions, but after normalization of these results to the cholesterol content of lipoprotein particles only the alpha-tocopherol content of low density lipoprotein remained higher after 60 days of cholesterol feeding. The data suggest that low glutathione peroxidase and superoxide dismutase fraction C activities may facilitate intravascular lipoprotein oxidation by oxidant species generated by the endothelium or blood cells.

Plasma kinetics and biodistribution of a lipid emulsion resembling low-density lipoprotein in patients with acute leukemia

Low-density lipoprotein (LDL) could be used as a carrier of chemotherapeutic agents to neoplastic cells that overexpress LDL receptors (rLDL), but LDL is difficult to obtain and handle. Recently, it was observed that a protein-free emulsion resembling the lipid portion of LDL (LDE) behave like native LDL when injected into the bloodstream. In this study, the evidence that LDE is taken up by rLDL was expanded by comparing LDL and LDE plasma decay curves in rabbits and by competition experiments with lymphocytes. To verify whether LDE could be removed from the plasma by neoplastic cells with increased rLDL, LDE labeled with 14Ccholesteryl ester was injected into 14 patients with acute myeloid leukemia (AML) and into 7 with acute lymphocytic leukemia (ALL). In AML rLDL expression is increased but in ALL it is normal. LDE plasma fractional clearance rate (FCR, in h-1) was calculated from the remaining radioactivity measured in plasma samples collected during 24 h following injection. LDE FCR was 3-fold greater in AML than in ALL patients 0.192 +/- 0.210 (SD) and 0.066 +/- 0.033 h-1, respectively, P < 0.035. When LDE injection was repeated in 9 AML patients in hematological remission, LDE FCR diminished 66% compared to the pretreatment values (from 0.192 +/- 0.210 to 0.065 +/- 0.038 h-1, P < 0.02), so that it could be estimated that nearly 66% of the emulsion was taken up by AML cells and only 34% by the normal tissues. As expected, LDE FCR was unchanged in 4 patients with ALL in hematological remission (0.069 +/- 0.044 h-1). Gamma camera images obtained 6 h after the injection of 99mTc-label LDE into one patient with ALL showed biodistribution similar to that of LDL. In one AML patient LDE was comparatively more concentrated over the areas corresponding to the bone marrow infiltrated by AML cells. Our results indicate that LDE FCR is increased in a disease known to contain malignant cells that overexpress rLDL, suggesting that LDE is taken up by malignant cells with increased rLDL.

Metabolism of a chylomicron-like emulsion in rats with Walker 256 tumor: influence of a polyunsaturated (n-6) compared with a saturated fatty acid-rich diet

OBJECTIVE

Defects in lipid metabolism secondary to development of cancer are frequently observed and, in experimental animals, manipulation of the lipid content of the diet can significantly influence tumor growth. The effects of a high polyunsaturated fat vs a high saturated fat diet upon the chylomicron metabolism of rats bearing Walker 256 tumor were examined.

METHODS

Chylomicron-like emulsions labeled with radioactive lipids were injected into rats bearing the tumor and control rats. The two groups were previously given a high polyunsaturated (n-6) (15% fat) or a high saturated fat diet (15% fat) for 6 weeks. Following injection, plasma samples were collected at 8 time intervals in 60 minutes and tissue fragments were excised after the animals were killed, for determination of the plasma fractional clearance rate (FCR, min-1) and organ uptake of radioactive lipids.

RESULTS

FCR of the emulsion triacylglycerols (TG) and cholesteryl oleate ether (CE) decreased in the tumor-bearing rats fed the polyunsaturated fat-rich diet (FCR-TG control = 0.26 +/- 0.09, tumor = 0.11 +/- 0.04; FCR-CE controls = 0.18 +/- 0.05, tumor = 0.10 +/- 0.02), as did activity of the lipoprotein and hepatic lipases (p < 0.05). This indicates that in this group, the presence of the tumor elicited defective lipolysis and delayed removal of the emulsion from the plasma. In the group fed the saturated fatty acid-rich diet, however, these alterations were not observed (FCR-TG control = 0.21 +/- 0.11, tumor = 0.20 +/- 0.08; FCR-CE control = 0.13 +/- 0.06, tumor = 0.10 +/- 0.05). The uptake by several tissues of the emulsion CE was similar in all rat groups.

CONCLUSION

The saturated fat-rich diet avoids the deficiency in chylomicron lipolysis elicited by the implanted Walker 256 tumor.

Collaboration between providers and client-consumers in public mental health programs

As client-consumer groups grow, their role in the design and implementation of community mental health services is enlarged. Just as the psychotherapist must pay attention to the client's desires, so must mental health providers pay close attention to the wishes of client-consumers and their potential contribution to the evolution of the service delivery system.