Low levels of essential fatty acids are related to impaired delayed skin hypersensitivity in malnourished chronically ill elderly people

The Extension of the LeiCNS-PK3.0 Model in Combination with the "Handshake" Approach to Understand Brain Tumor Pathophysiology

Micrometastatic brain tumor cells, which cause recurrence of malignant brain tumors, are often protected by the intact blood–brain barrier (BBB). Therefore, it is essential to deliver effective drugs across not only the disrupted blood-tumor barrier (BTB) but also the intact BBB to effectively treat malignant brain tumors. Our aim is to predict pharmacokinetic (PK) profiles in brain tumor regions with the disrupted BTB and the intact BBB to support the successful drug development for malignant brain tumors. LeiCNS-PK3.0, a comprehensive central nervous system (CNS) physiologically based pharmacokinetic (PBPK) model, was extended to incorporate brain tumor compartments. Most pathophysiological parameters of brain tumors were obtained from literature and two missing parameters of the BTB, paracellular pore size and expression level of active transporters, were estimated by fitting existing data, like a “handshake”. Simultaneous predictions were made for PK profiles in extracellular fluids (ECF) of brain tumors and normal-appearing brain and validated on existing data for six small molecule anticancer drugs. The LeiCNS-tumor model predicted ECF PK profiles in brain tumor as well as normal-appearing brain in rat brain tumor models and high-grade glioma patients within twofold error for most data points, in combination with estimated paracellular pore size of the BTB and active efflux clearance at the BTB. Our model demonstrated a potential to predict PK profiles of small molecule drugs in brain tumors, for which quantitative information on pathophysiological alterations is available, and contribute to the efficient and successful drug development for malignant brain tumors.

Global survey of the omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the blood stream of healthy adults

Studies reporting blood levels of the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were systematically identified in order to create a global map identifying countries and regions with different blood levels. Included studies were those of healthy adults, published in 1980 or later. A total of 298 studies met all inclusion criteria. Studies reported fatty acids in various blood fractions including plasma total lipids (33%), plasma phospholipid (32%), erythrocytes (32%) and whole blood (3.0%). Fatty acid data from each blood fraction were converted to relative weight percentages (wt.%) and then assigned to one of four discrete ranges (high, moderate, low, very low) corresponding to wt.% EPA+DHA in erythrocyte equivalents. Regions with high EPA+DHA blood levels (>8%) included the Sea of Japan, Scandinavia, and areas with indigenous populations or populations not fully adapted to Westernized food habits. Very low blood levels (≤4%) were observed in North America, Central and South America, Europe, the Middle East, Southeast Asia, and Africa. The present review reveals considerable variability in blood levels of EPA+DHA and the very low to low range of blood EPA+DHA for most of the world may increase global risk for chronic disease.

Reversibility of protein-energy malnutrition in a group of chronically-ill elderly outpatients

Nutritional status was studied in 23 elderly (74 +/- 1 years), malnourished outpatients with non-malignant diseases. The patients' recollections and medical records indicated a gradual weight loss of approximately 25% in the preceding 2-15 years; only a small amount (6%) was lost during the final 6 months. At a re-examination after 3 months, all patients were still malnourished but in general the depletion had decreased. An elevated level of serum orosomucoid (orosomucoid positive) was used as evidence of an on-going inflammatory process. The 14 orosomucoid negative patients displayed a more pronounced improvement in their nutritional status than those who were orosomucoid positive. 15 patients were prescribed a protein and energy enriched formula (40 g protein and 400/1.7 kcal/MJ per day). The orosomucoid positive and orosomucoid negative groups did not differ in number of subjects prescribed supplementation. During the follow-up period the patients that were recommended supplementation showed a more prominent improvement in their nutritional status than the 'non-supplemented' subjects. Discriminant analysis revealed that prescription of oral supplementation and, to a lesser extent, serum orosomucoid concentrations within the reference range favoured nutritional repletion. The most pronounced recovery was registered in orosomucoid negative patients who had been prescribed supplementation.

Nutritional supplementation and dietary advice in geriatric patients at risk of malnutrition

BACKGROUND & AIM

Effects of combined nutritional treatment of patients at risk of protein-energy malnutrition (PEM) discharged from a geriatric service were evaluated.

METHODS

Patients (n=108, age 85+/-6 years) at risk of malnutrition according to the short form of the mini nutritional assessment were randomly allocated to dietary counseling, including liquid and multivitamin supplementation, i.e. intervention (I, n=51) and to controls (C, n=57). Body weight, biochemical indices (e.g. insulin-like growth factor I (IGF-I)), Katz activities of daily living (ADL) index, mini mental status examination (MMSE) and quality of life (QoL) by SF-36 were assessed at the start of the study and after 4 months. Statistical analyses were performed on "intention-to-treat" and on "treated-as-protocol" bases.

RESULTS

Fifty-four patients, 29 in the I-group (86+/-7 years, 66% females) and 25 in the C-group (85+/-7 years, 72% females) completed the study according to the protocol. Both modes of analysis revealed a significant positive effect of the combined nutritional intervention on weight maintenance. Treated-as-protocol analyses showed that Katz ADL index improved in the I-group (p<0.001; p<0.05 between the groups). Serum IGF-I levels increased in the I-group (p<0.001), but were unchanged in the C-group (p=0.07 between the groups). QoL was assessed to be low and had not changed after nutritional treatment.

CONCLUSIONS

Combined nutritional intervention prevented weight loss and improved ADL functions in discharged geriatric patients at risk of malnutrition.

Delayed-type hypersensitivity and humoral immunity modulation by dietary lipids in a murine model of pulmonary tumorigenesis induced by urethan

Mice fed on semisynthetic formulas containing 15% of corn oil (CO), cod fish liver oil (FO), oleic acid (O) or a mixture of 46% of palmitic and 50% of stearic acids (PS) were treated with urethan during 18 weeks for lung tumor induction. Delayed-type hypersensitivity (DTH) assay, hemagglutination assay and the amount of lung nodes (alveolar adenocarcinomas) were recorded. Results showed significantly greater DTH in CO and FO with respect to O and PS feeding mice; the two last ones induced an essential fatty acid (EFA) deficiency (EFAD). In the O lot there was a non-significant diminution of the humoral response. EFAD animals exhibited a tendency to increase number of lung nodes in relation to CO and FO lots. Splenomegalia was recorded in FO lot. Confront between spleen weight and DTH showed a 72% correlation, suggesting an increase in cellular immunity as increasing unsaturation. It may be concluded that in this suitable model of tumorigenesis the manipulation of dietary lipids may be a strategy to modify the immune system response.

The prevalence of anergy in human immunodeficiency virus-infected adolescents and the association of delayed-type hypersensitivity with subject characteristics

PURPOSE

To examine the prevalence of anergy in HIV-infected adolescents and factors associated with its occurrence.

METHODS

Anergy was defined as less than 2mm induration to each of three intradermally applied antigens (Candida albicans, tetanus toxoid, and mumps) between 24 and 96 hours in a population of HIV-infected adolescents aged 12-18 at entry in a national multicenter study of HIV disease progression. CD4(+) T-cell counts and plasma HIV-1 RNA were measured in quality controlled laboratories. Factors associated with the probability of anergy were examined with contingency table comparisons, tree-structured classification, and logistic regression analyses.

RESULTS

Overall prevalence of anergy in this clinic-based population of 167 was 11% [7% in males and 12% in females (p = 0.57)]. The sole significant predictor of anergy was decreased CD4(+) T-cell count (p = 0.005).

CONCLUSION

The prevalence of anergy is low in this HIV-infected population compared to older infected cohorts. The occurrence of differential rates of anergy in particular age and sex groupings that may be related to intrinsic immunologic differences requires further study.

Impaired leukotriene C4 generation in granulocytes from protein-energy malnourished chronically ill elderly

OBJECTIVE

The dysregulation of the immune and inflammatory systems observed in protein-energy malnutrition (PEM) may be partly due to perturbation of essential fatty acid metabolism. In this study, we assessed the calcium ionophore A23187-induced generation of the arachidonate metabolites leukotriene B4 (LTB4) and leukotriene C4 (LTC4) in isolated granulocyte suspensions.

DESIGN

Case-control study.

SETTING

A university-affiliated acute care hospital in urban Stockholm.

SUBJECTS

Fourteen severely malnourished elderly subjects with stable non-malignant disorders (age 74 +/- 1 years, mean +/- SEM) and 12 healthy age-matched controls were examined.

MAIN OUTCOME MEASURES

Leukotrienes were analysed by high-performance liquid chromatography. Body mass index (BMI, kg m-2) and delayed cutaneous hypersensitivity (DCH) reaction were determined.

RESULTS

BMI was 16. 5 +/- 0.5 and 26.2 +/- 0.9 kg m-2 (mean +/- SE) in the malnourished group and controls (P < 0.001), respectively. DCH was 8.5 mm (median) in patients and 29.5 mm in controls (P < 0.001). LTC4 generation in granulocytes from PEM patients was half of that of controls (9.1 +/- 2.0 vs. 17.8 +/- 5.2 pmol mL-1, P < 0.05) when cells were stimulated with 0.2 micromol L-1 of A23187, and 13.7 +/- 2.5 and 27.2 +/- 7.5 pmol mL-1, respectively (NS), upon stimulation with 1.0 micromol L-1 of A23187. LTB4 production in PEM patients and controls did not differ at any of the two calcium ionophore concentrations. LTC4 production correlated with BMI (r = 0.41, P < 0.05), but there was no significant correlation between DCH and LTB4 or LTC4 production.

CONCLUSION

Protein-energy malnutrition is accompanied by perturbation of leukotriene synthesis, which may be one factor underlying the dysregulation of inflammatory responses in the depleted patient.

Differences in essential fatty acid requirements by enteral and parenteral routes of administration in patients with fat malabsorption

BACKGROUND

Essential fatty acid (EFA) requirements of patients receiving home parenteral nutrition (HPN) are uncertain.

OBJECTIVE

The objective was to evaluate the influence of the route of administration (enteral compared with parenteral) on plasma phospholipid EFA concentrations.

DESIGN

Intestinal absorption, parenteral supplement of EFAs, and plasma phospholipid EFA concentrations were investigated in balance studies in 4 groups (A, B, C, and D) of 10 patients with short-bowel syndrome and a fecal loss of >2000 kJ/d. Groups A (fat malabsorption <50%) and B (fat malabsorption >50%) did not receive HPN, whereas group C received HPN containing lipids (7.5 and 1.2 g/d linoleic and linolenic acids, respectively) and group D received fat-free HPN.

RESULTS

Intestinal absorption of linoleic and linolenic acids was 8.9 and 1.3 g/d and 2. 6 and 0.4 g/d in groups A and B, respectively, whereas EFA absorption was negligible in groups C and D. Thus, intestinal absorption of EFAs in group A corresponded to parenteral EFA supplements in group C, whereas group D was almost totally deprived of EFAs. The median plasma phospholipid concentration of linoleic acid decreased by 21.9%, >16.3%, >13.8%, 11.0%, and >7.7% and linolenic acid by 0.3%, 0.2%, 0.2%, >0.2%, and 0.1%, respectively, in 10 healthy control subjects and groups A, B, C, and D (P < 0.001).

CONCLUSIONS

Intestinally absorbed EFAs maintained plasma EFA status better than did an equal quantity of parenterally supplied EFAs. Intravenous requirements of EFAs in patients with negligible absorption of EFAs are probably higher than the amounts recommended to patients with preserved intestinal absorption of EFAs.

Impaired granulocyte formylpeptide-induced superoxide generation in chronically ill, malnourished, elderly patients

OBJECTIVE

Protein-energy malnutrition (PEM), often occurring in patients with chronic disease, is associated with a decreased capacity to combat infections. In this study we assessed polymorphonuclear neutrophil (PMN) superoxide anion (*O2-) formation in elderly PEM patients with various chronic diseases.

DESIGN AND SUBJECTS

Nineteen patients (75+/-1 years), with body mass index 17.1+/-0.4, and 19 age-matched healthy controls were included. Fourteen patients and 14 controls were re-examined in a 3 month follow-up.

SETTING

A service of internal medicine at a university-affiliated hospital.

INTERVENTIONS

Eight patients were prescribed a dietary liquid supplementation during the observation period.

MAIN OUTCOME MEASURES

Superoxide production in PMN induced by fMLP (a receptor ligand) and phorbol myristate acetate (PMA), which acts directly on protein kinase C.

RESULTS

fMLP-induced superoxide generation in the malnourished patients was 55+/-5% of that of the controls. However, the patients retained their capacity, 108+/-6% of control PMN generation, to respond to PMA. In those who received formula supplementation, fMLP-generated *O2- production levels were 48+/-8 and 73+/-13% (P = 0.12) of those of controls at the start and after 3 months, respectively. Corresponding figures in those who were not prescribed supplementation were 57+/-8 and 64+/-4% (P = 0.55).

CONCLUSION

Possibly contributing to reduced host defence, receptor ligand-induced PMN generation of *O2 is significantly lower in chronically ill, elderly patients with PEM than in age-matched healthy controls.

Skin test anergy in advanced heart failure secondary to either ischemic or idiopathic dilated cardiomyopathy

Skin tests to recall antigens are performed as indicators of clinical outcomes in heart failure (HF). A diminution in the response to recall antigens, termed "anergy," is regarded as an indication of poorer clinical prognosis, although little analysis has been done to support that conclusion. Patients with advanced HF (n=222) in New York Heart Association classes III and IV, with complete datasets for all of the variables, were studied. The sample was 77% men, mean age 52+/-12 years, and left ventricular ejection fraction, 21+/-7. Patients with ischemic (n=113) and idiopathic (n=109) disease were analyzed separately. The relation of anergy to 1-year mortality and selected hemodynamic factors, blood chemistries, medications, and nutritional status markers was analyzed. Anergy was present in 45% (47% idiopathic and 42% ischemic) of patients. Anergy was related to 1-year mortality (univariate p=0.038) in patients with ischemic, but not idiopathic, HF. Anergic patients with ischemic HF had shorter survival times (p=0.035). Lower cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides were predictors (p <0.001) of mortality in idiopathic HF. In ischemic HF, lower cholesterol, LDL, and triglycerides were univariate predictors (p <0.001, p=0.004, and p=0.005, respectively) of skin test anergy, but not mortality. Thus, there were distinct differences in clinical correlates of skin test anergy in patients with idiopathic and ischemic HF. This study supports evaluation of anergy to skin tests as one of the markers of mortality in patients with ischemic HF.