Dietary fatty acids influence the production of Th1- but not Th2-type cytokines

C57B16 mice were fed for 6 weeks on a low-fat diet or on high-fat diets containing coconut oil (rich in saturated fatty acids), safflower oil [rich in n-6 polyunsaturated fatty acids (PUFAs)], or fish oil (rich in n-3 PUFAs) as the main fat sources. The fatty acid composition of the spleen lymphocytes was influenced by that of the diet fed. Thymidine incorporation into concanavalin A-stimulated spleen lymphocytes and interleukin (IL)-2 production were highest after feeding the coconut oil diet. Interferon (IFN)-gamma production was decreased by safflower oil or fish oil feeding. IL-4 production was not significantly affected by diet, although production was lowest by lymphocytes from fish oil-fed mice. The ratio of production of Th1- to Th2-type cytokines (determined as the IFN-gamma/IL-4 ratio) was lower for lymphocytes from mice fed the safflower oil or fish oil diets. After 4 h of culture, IL-2 mRNA levels were higher in cells from mice fed coconut oil, and IFN-gamma mRNA levels were higher in cells from mice fed coconut oil or safflower oil. After 8 h of culture, IL-2, IFN-gamma, and IL-4 mRNA levels were lowest in cells from mice fed fish oil. The ratio of the relative levels of IFN-gamma mRNA to IL-4 mRNA was highest in cells from mice fed coconut oil and was lowest in cells of mice fed fish oil. The influence of individual fatty acids on IL-2 production by murine spleen lymphocytes was examined in vitro. Although all fatty acids decreased IL-2 production in a concentration-dependent manner, saturated fatty acids were the least potent and n-3 PUFAs the most potent inhibitors, with n-6 PUFAs falling in between in terms of potency. It is concluded that saturated fatty acids have minimal effects on cytokine production. In contrast, PUFAs act to inhibit production of Th1-type cytokines with little effect on Th2-type cytokines; n-3 PUFAs are particularly potent. The effects of fatty acids on cytokine production appear to be exerted at the level of gene expression.     

Risk factors for mortality in young children living under various socio-economic conditions in Lahore, Pakistan: with particular reference to inbreeding

Risk factors such as maternal age, parity, previous siblings' death, inbreeding of parents, birth weight, birth length were examined in a population-based prospective study in four population groups at different levels of urbanization in and round Lahore, Pakistan. From September 1984 to March 1995, 2967 full-term, single born infants were followed from the 5th month of gestation to 12 months of age. Logistic regression analysis showed a significant relative risk (RR) of infant death associated with parents' consanguinity (RR = 1.8), birth weight (RR = 1.8) and elder siblings' death (RR = 1.7). The risk attributed to these factors was 28, 17 and 25%, respectively. The number of lethal equivalents per gamete is about one. The B/A ratio 10.36 suggests that the genetic load is likely to be mutational. In countries like Pakistan, where consanguinity is favourably practiced, a substantial proportion of infant deaths may be prevented by cessation of such marriages. The implications of this finding for the Pakistani community are discussed.     

Identification of unilateral elbow-joint position is impaired by Parkinson's disease

We have compared the ability of patients with idiopathic Parkinson's disease (PD) with that of control subjects to identify unilateral elbow-joint position, in the absence of direct vision of the arm, by visual reference to a graduated angular scale, placed beside the elbow, across a range of test angles of 90-108 degrees. The positioning of the subject's elbow was achieved under either passive (subject relaxed, Experiment 1) or active (subject contracting, Experiment 2) conditions. PD patients' performance (while on L-dopa medication) with the elbows on the sides of "worse" and "better" motor signs was compared with that of controls with, respectively, the left and right elbows. In both experiments, (a) both the individual, overall mean unsigned (with respect to direction) error averaged across all test angles (accuracy), and the SD about this mean (precision), were significantly larger on each side among PD patients than among controls, and (b) the subjective ranges of values employed by PD patients were substantially compressed, on average, by comparison with those of controls. Within-group analyses revealed that (a) among control subjects, but not among PD subjects, individual, overall mean unsigned errors, on each side, averaged across test angles, were significantly smaller under active than under passive conditions, and (b) the subjective ranges employed by PD patients, but not by controls, under active conditions significantly exceeded those under passive conditions. We conclude that these results are generally consistent with the notion that PD impairs unilateral elbow-joint position sense.     

Extracellular signal-regulated kinase (ERK) in glucose-induced and endothelin-mediated fibronectin synthesis

Increased extracellular matrix protein deposition and basement membrane thickening are important features of diabetic angiopathy. One key matrix protein that has been shown to be instrumental in basement membrane thickening is fibronectin (FN). We have previously demonstrated that glucose-induced increased expression of endothelin-1 (ET-1), may in part, be responsible for increased FN expression via nuclear factor-kappaB (NF-kappaB) and activating protein (AP-1) activation. The present study was aimed at elucidating the mechanism of ET-1 with respect to mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway activation and glucose-induced FN upregulation. Human endothelial cells were exposed to either low (5 mM) or high (25 mM) glucose levels. Cells in low glucose were also treated with ET-1 peptide (5 nM). In addition, we treated cells exposed to high glucose levels with specific MAPK/ERK inhibitor PD098059 (50 microM), dual ET-receptor antagonist, bosentan (10 microM), and PKC blocker, chelerythrine (1 microM). Following incubation period, RNA and total proteins were extracted for RT-PCR for FN and immunoblot analysis of MAPK/ERK activation. Confocal microscopy was performed for analysis of FN protein and nuclear localization of activated Elk. Electrophoretic mobility shift assay was carried out to detect NF-kappaB and AP-1 activation. Our data demonstrates that high glucose-induced upregulation of FN messenger RNA and protein levels occur via activation of MAPK/ERK pathway, which was prevented by treatment of cells with bosentan, PD098059 and PKC blocker chelerythrine. Confocal microscopy demonstrated nuclear localization of phospho-Elk protein. Glucose-induced FN expression was also associated with protein kinase C, NF-kappaB, and AP-1 activation. These results suggested that glucose-induced, ET- and PKC-dependent, upregulation of FN is, in part, mediated via MAPK/ERK activation.     

Increased nitric oxide synthesis in uraemic platelets is dependent on L-arginine transport via system y(+)L

Bleeding tendency in uraemic patients seems to be related to alterations in the activity of the L-arginine-nitric oxide (NO) signalling pathway in platelets. We have reported previously that L-arginine influx into human platelets is mediated by the high-affinity cationic amino acid transport system y(+)L. In the present study we examined the dependency of nitric oxide synthase (NOS) activity on L-arginine transport in platelets isolated from healthy controls and uraemic patients on haemodialysis. We investigated basal and ADP-stimulated NOS activity, as reflected by the conversion of L-[(3)H]arginine to L-[(3)H]citrulline, in platelets obtained from healthy controls and uraemic patients on haemodialysis. To determine whether NOS activity depended on L-arginine transport, we analysed the effects of competitive inhibitors of L-arginine transport via system y(+)L on NOS activity. Basal NOS activity was increased from 0.21+/-0.06 to 0.7+/-0.2 pmol/10(8) platelets ( n=9, P<0.05) in uraemic patients. Stimulation by ADP (10 micro M) significantly increased NOS activity (inhibitable by L-NAME) in control platelets (252%) but failed to increase further the elevated NOS activity in uraemic platelets. Homocysteine and L-leucine, competitive inhibitors of system y(+)L, markedly inhibited NOS activity in uraemic platelets. These observations indicate that platelets from uraemic patients on haemodialysis generate more NO than control platelets and that entry of L-arginine via system y(+)L is most likely rate-limiting for platelet NO production in chronic renal failure.     

Development of a bleomycin hamster model of subchronic lung fibrosis.

The existing bleomycin (BLM)-rodent model of lung fibrosis requires large doses and is often associated with morbidity and high mortality. We have developed an intratracheal multiple-dose BLM-hamster model of lung fibrosis. In this model, 3 consecutive doses of BLM (2.5 U, 2.0 U and 1.5 U/5mL/kg) were instilled intratracheally, one dose per week. The hamsters were killed at 10, 20, 30, 60 and 90 days after the last IT instillation and the lungs were lavaged or perfused with saline. This regimen of BLM administration was devoid of morbidity and caused only 6% overall mortality. Lung prolyl hydroxylase activity at 10 days and hydroxyproline content at 20, 30, 60 and 90 days were significantly higher than noted for the controls. Bronchoalveolar lavage fluid-supernatant protein and the total number of recovered cells of all types were significantly higher than observed for the controls at all times, except at 90 days. Lungs showed a multifocal mixed mononuclear infiltrate at 10 and 20 days and septal fibrosis, which was most severe and organized at 30 days and less severe at 60 and 90 days. The parenchymal lesions were significantly greater than those of the controls at all times, except at 10 days. This model, which required only 6 U BLM/kg, induced a moderate level of lung fibrosis. It has been concluded, therefore, that this model, inasmuch as it is not associated with an overwhelmingly acute inflammation, would be more applicable for screening potential antifibrotic agents than existing models of lung fibrosis.     

A phase II trial of neoadjuvant docetaxel and capecitabine for locally advanced breast cancer.

PURPOSE: This study evaluated the toxicity and efficacy of docetaxel/capecitabine as neoadjuvant treatment for stage 2/3 breast cancer. EXPERIMENTAL DESIGN: Subjects with newly diagnosed invasive stage 2 and 3 breast cancer were eligible. The first cohort of patients was treated at dose A with neoadjuvant docetaxel (75 mg/m(2) i.v. day 1) and capecitabine (1000 mg/m(2) orally twice daily days 2-15) for four cycles. A second cohort of subjects was treated with a reduced dose, dose B, of docetaxel (60 mg/m(2) i.v. day 1) and capecitabine (937.5 mg/m(2) orally twice daily days 2-15). RESULTS: Thirty patients were enrolled. Eight of 10 patients treated at dose A required dose reductions of either docetaxel or capecitabine secondary to grade 3 or 4 toxicities: mucositis (1), hand-foot syndrome (3), diarrhea (2), perirectal abscess (1), and neutropenia (2). Because of a high rate of dose reductions, the next 20 patients were treated at dose B. The mean cumulative administered dose of docetaxel was 285 and 231 mg/m(2) at dose A and dose B, respectively. For capecitabine, the mean cumulative dose at dose A and B were similar at 1585 and 1627 mg/m(2)/day, respectively. The overall clinical response rate was 90% with 31% of patients having a complete response and 59% having a partial response. A pathological complete response in the breast was achieved in 10% of patients after four cycles of docetaxel/capecitabine. CONCLUSIONS: Docetaxel/capecitabine is a highly active regimen in the neoadjuvant setting. Neoadjuvant therapy with 75 mg/m(2) docetaxel and 1600 mg/m(2)/day days 2-15 is recommended.     

Inhibition of CFU-E colony formation in uremic patients with inflammatory disease: role of IFN-gamma and TNF-alpha.

BACKGROUND: There is evidence for the role of inflammatory cytokines in the inhibition of erythropoiesis in the anemia of chronic disease, but the extent to which they contribute to resistance to erythropoietin (EPO) in patients with chronic renal failure is not clear. The purpose of the present study was to assess the effect of sera from patients with end-stage renal failure with and without infection or inflammatory disease on CFU-E colony formation in vitro. METHODS: Bone marrow was obtained from uremic patients with inflammatory disease and from healthy controls. Standard colony assays were used to assess erythroid colony formation (CFU-E) in response to EPO in the presence or absence of 5% autologous serum. Normal bone marrow mononuclear cells were cultured with 5% v/v sera from three groups of patients: healthy volunteers, uremic controls, and uremic patients with inflammatory disease. RESULTS: There was no difference between normal and uremic bone marrow response to EPO. However, when uremic/inflammatory bone marrow was cultured with autologous serum the optimal response to EPO was significantly inhibited. Optimal CFU-E colony formation was suppressed significantly by sera from either uremic group when compared with cultures containing sera from controls. Treatment of parallel cultures with a combination of antibodies to interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) almost completely restored the response to EPO. Additionally, bone marrow from healthy controls incubated with uremic sera showed an increased production of interleukin-1 alpha (IL-1 alpha) and IFN-gamma, and TNF-alpha was present in uremic sera. CONCLUSIONS: CFU-E colony formation is inhibited by soluble factors present in the sera of uremic patients with or without inflammatory disease. These soluble factors stimulate the production of IFN-gamma and TNF-alpha, which directly inhibit erythropoiesis at a local level in the bone marrow.     

Cross talk between drug-resistant epilepsy and the gut microbiome

One-third of epilepsy patients have drug-resistant epilepsy (DRE), which is often complicated by polydrug toxicity and psychiatric and cognitive comorbidities. Advances in understanding the microbiome and gut-brain-axis are likely to shed light on epilepsy pathogenesis, anti-seizure medication (ASM) resistance, and potential therapeutic targets. Gut dysbiosis is associated with inflammation, blood-brain barrier disruption, and altered neuromodulators. High-throughput and metagenomic sequencing has advanced the characterization of microbial species and functional pathways. DRE patients show altered gut microbiome composition compared to drug-sensitive patients and healthy controls. The ketogenic and modified Atkins diets can reduce seizures in some patients with DRE. These low-carbohydrate dietary therapies alter the taxonomic and functional composition of the gut microbiome, and composition varies between diet responders and nonresponders. Murine models suggest that specific phyla are necessary to confer efficacy from the diet, and antibiotic treatment may eliminate efficacy. The impact of diet might involve alterations in microbiota, promotion of select microbial interactions, and variance in brain neurotransmitter levels that then influence seizures. Understanding the mechanics of how diet manipulates seizures may suggest novel therapies. Most ASMs act on neuronal transmission via effects on ion channels and neurotransmitters. However, ASMs may also assert their effects via the gut microbiota. In animal models, the microbiota composition (eg, abundance of certain phyla) can vary with ASM active drug metabolites. Given the developing understanding of the gut microbiome in DRE, probiotics are another potential therapy. Probiotics alter the microbiota composition, and small studies suggest that these supplements can reduce seizures in some patients. DRE has enormous consequences to patients and society, and the gut microbiome holds promise as a potential therapeutic target. However, the exact mechanism and recognition of which patients are likely to be responders remain elusive. Further studies are warranted.