Evaluation of the in vitro production of interferon gamma and other lymphokines in uremic patients

It has been suggested that a deficient immune response can be responsible at least partially for the high risk of infections and neoplasia in uremic patients. Since interferon (IFN) is critical to the immune response, we have evaluated the in vitro production of IFN-gamma and other lymphokines by peripheral blood mononuclear cells (PBMC) drawn from patients with end-stage renal disease and appropriate controls. We have correlated production of lymphokines by these cells with proliferative response to different mitogens. It was found that the secretion of IFN-gamma in response to all three mitogens was elevated in these patients compared with the control group. This elevation was significant with both phytohemagglutin and staphylococcal enterotoxin A, but not with Con A. No significant difference was observed in production of lymphotoxins, IL-2, and leukocyte migration inhibition responses. In contrast the proliferative response appeared diminished in the PBMC of uremic patients. We concluded that defective lymphokine generation is not a major immunological problem in patients with end-stage renal disease. Indeed, they appear to release excess amount of IFN-gamma which is known to be a macrophage-activating factor. It is suggested that high IFN-gamma activity could enhance the secretion of IL-1 or endogenous pyrogen and result in development of febrile reactions in dialysis patients.     

The effect of beta-estradiol, progesterone and testosterone on the production of human leukocyte derived interferons

Sex hormones including estrogens, progesterone and testosterones are known to have adverse effects on the immune system and particularly on the proliferative response. Since cytokine production is known to be dissociable from the proliferation of lymphocytes and since other steroid hormones profoundly affect cytokine production, we felt it would be important to know the effect of sex steroids on the production of interferons (IFN), particularly since the latter are known to be key substances in the immune response. We have shown estradiol can slightly reduce gamma IFN yields with certain inducers (Con A, SEA) but only in pharmacologic concentrations. Similarly, progesterone had a modest effect in the same concentrations but only when Con A was the inducer. Testosterone did not effect IFN titers at any concentration. None of the sex steroids affected alpha IFN production and none of them influenced the bioactivity of either IFN species. In all cases these hormones diminished proliferative responses as has been previously noted.     

Eledoisin and Kassinin, but not Enterokassinin, stimulate ion transport in frog skin

In frog skin, tachykinins stimulate the ion transport, estimated by measuring the short-circuit current (SCC) value, by interacting with NK1-like receptors. In this paper we show that Kassinin (NK2 preferring in mammals) increases the SCC, while Enterokassinin has no effect. Therefore, either 2 Pro residues or 1 Pro and 1 basic amino acid must be present in the part exceeding the C-terminal pentapeptide. Eledoisin (NK3 preferring in mammals) stimulation of SCC is reduced by CP99994 and SR48968 (NK1 and NK2 antagonists) and not affected by SB222200 (NK3 antagonist). None of the three antagonists affects Kassinin stimulation of SCC.     

Intra-Arterial Transplantation of Allogeneic Mesenchymal Stem Cells Mounts Neuroprotective Effects in a Transient Ischemic Stroke Model in Rats: Analyses of Therapeutic Time Window and Its Mechanisms

Objective

Intra-arterial stem cell transplantation exerts neuroprotective effects for ischemic stroke. However, the optimal therapeutic time window and mechanisms have not been completely understood. In this study, we investigated the relationship between the timing of intra-arterial transplantation of allogeneic mesenchymal stem cells (MSCs) in ischemic stroke model in rats and its efficacy in acute phase.

Methods

Adult male Wistar rats weighing 200 to 250g received right middle cerebral artery occlusion (MCAO) for 90 minutes. MSCs (1×10⁶cells/ 1ml PBS) were intra-arterially injected at either 1, 6, 24, or 48 hours (1, 6, 24, 48h group) after MCAO. PBS (1ml) was intra-arterially injected to control rats at 1 hour after MCAO. Behavioral test was performed immediately after reperfusion, and at 3, 7 days after MCAO using the Modified Neurological Severity Score (mNSS). Rats were euthanized at 7 days after MCAO for evaluation of infarct volumes and the migration of MSCs. In order to explore potential mechanisms of action, the upregulation of neurotrophic factor and chemotactic cytokine (bFGF, SDF-1α) induced by cell transplantation was examined in another cohort of rats that received intra-arterial transplantation at 24 hours after recanalization then euthanized at 7 days after MCAO for protein assays.

Results

Behavioral test at 3 and 7 days after transplantation revealed that stroke rats in 24h group displayed the most robust significant improvements in mNSS compared to stroke rats in all other groups (p’s<0.05). Similarly, the infarct volumes of stroke rats in 24h group were much significantly decreased compared to those in all other groups (p’s<0.05). These observed behavioral and histological effects were accompanied by MSC survival and migration, with the highest number of integrated MSCs detected in the 24h group. Moreover, bFGF and SDF-1α levels of the infarcted cortex were highly elevated in the 24h group compared to control group (p’s<0.05).

Conclusions

These results suggest that intra-arterial allogeneic transplantation of MSCs provides post-stroke functional recovery and reduction of infarct volumes in ischemic stroke model of rats. The upregulation of bFGF and SDF-1α likely played a key mechanistic role in enabling MSC to afford functional effects in stroke. MSC transplantation at 24 hours after recanalization appears to be the optimal timing for ischemic stroke model, which should guide the design of clinical trials of cell transplantation for stroke patients.     

Oxidative stress-related biomarkers in autism: systematic review and meta-analyses

Autism spectrum disorders (ASDs) are rarely diagnosed in children younger than 2 years, because diagnosis is based entirely on behavioral tests. Oxidative damage may play a central role in this pathogenesis, together with the interconnected transmethylation cycle and transsulfuration pathway. In an attempt to clarify and quantify the relationship between oxidative stress-related blood biomarkers and ASDs, a systematic literature review was carried out. For each identified study, mean biomarker levels were compared in cases and controls providing a point estimate, the mean ratio, for each biomarker. After meta-analysis, the ASD patients showed decreased blood levels of reduced glutathione (27%), glutathione peroxidase (18%), methionine (13%), and cysteine (14%) and increased concentrations of oxidized glutathione (45%) relative to controls, whereas superoxide dismutase, homocysteine, and cystathionine showed no association with ASDs. For the C677T allele in the methylene tetrahydrofolate reductase gene (MTHFR), homozygous mutant subjects (TT) showed a meta-OR of 2.26 (95% CI 1.30-3.91) of being affected by ASD with respect to the homozygous nonmutant (CC). Case-control studies on blood levels of vitamins suggest a lack of association (folic acid and vitamin B12) or rare association (vitamins A, B6, C, D, E). Sparse results were available for other biomarkers (ceruloplasmin, catalase, cysteinylglycine, thiobarbituric acid-reactive substances, nitric oxide) and for polymorphisms in other genes. Existing evidence is heterogeneous and many studies are limited by small sample size and effects. In conclusion, existing evidence suggests a role for glutathione metabolism, the transmethylation cycle, and the transsulfuration pathway, although these findings should be interpreted with caution, and larger, more standardized studies are warranted.     

Genetic susceptibility to malignant pleural mesothelioma and other asbestos-associated diseases

Exposure to asbestos fibers is a major risk factor for malignant pleural mesothelioma (MPM), lung cancer, and other non-neoplastic conditions, such as asbestosis and pleural plaques. However, in the last decade many studies have shown that polymorphism in the genes involved in xenobiotic and oxidative metabolism or in DNA repair processes may play an important role in the etiology and pathogenesis of these diseases. To evaluate the association between diseases linked to asbestos and genetic variability we performed a review of studies on this topic included in the PubMed database. One hundred fifty-nine citations were retrieved; 24 of them met the inclusion criteria and were evaluated in the review. The most commonly studied GSTM1 polymorphism showed for all asbestos-linked diseases an increased risk in association with the null genotype, possibly linked to its role in the conjugation of reactive oxygen species. Studies focused on GSTT1 null and SOD2 Ala16Val polymorphisms gave conflicting results, while promising results came from studies on alpha1-antitrypsin in asbestosis and MPO in lung cancer. Among genetic polymorphisms associated to the risk of MPM, the GSTM1 null genotype and two variant alleles of XRCC1 and XRCC3 showed increased risks in a subset of studies. Results for the NAT2 acetylator status, SOD2 polymorphism and EPHX activity were conflicting. Major limitations in the study design, including the small size of study groups, affected the reliability of these studies. Technical improvements such as the use of high-throughput techniques will help to identify molecular pathways regulated by candidate genes.     

Retracted: Role of α7‐nicotinic acetylcholine receptor in human non‐small cell lung cancer proliferation

The above article from Cell Proliferation, published online on 18 November 2008 in Wiley Online Library ( wileyonlinelibrary.com ), and in Volume 41, pp. 936‐959, has been retracted by agreement between the Editor in Chief, Dr Catherine Sarraf, and John Wiley and Sons Ltd. The retraction has been agreed upon following the recent confirmation regarding an internal investigation that was conducted by the Institutional Office for Research Integrity (UIR) at the National Institute for Cancer Research, Genova, Italy, in 2009, which found evidence of fabricated/duplicated data within the article.     

Differences between ranamargarin and other tachykinins in the stimulation of ion transport in frog skin

In frog skin, tachykinins stimulate ion transport by interaction with NK1-like receptors. The structural requirements of the peptide are the presence of the C-terminal sequence Phe-X-Gly-Leu-Met-NH₂ and at least one Pro residue in the N-terminal sequence. In this paper, we demonstrate that the C-terminal amino acid must be amidated but it can be different from Met, and that the sequence cannot be longer or shorter than 11–12 amino acids. Unexpectedly, Ranamargarin (14 amino acids, no Pro residue) increased the short circuit current value by 48 ± 0.3%. On the basis of considerable experimental evidence, we suggest that Ranamargarin interacts with a receptor different from those of other tachykinins.     

Spinal Cord Stimulation Exerts Neuroprotective Effects against Experimental Parkinson’s Disease

In clinical practice, deep brain stimulation (DBS) is effective for treatment of motor symptoms in Parkinson’s disease (PD). However, the mechanisms have not been understood completely. There are some reports that electrical stimulation exerts neuroprotective effects on the central nervous system diseases including cerebral ischemia, head trauma, epilepsy and PD, although there are a few reports on neuroprotective effects of spinal cord stimulation (SCS). We investigated the neuroprotective effects of high cervical SCS on PD model of rats. Adult female Sprague-Dawley rats received hour-long SCS (2, 50 or 200 Hz) with an epidural electrode at C1–2 level for 16 consecutive days. At 2 days after initial SCS, 6-hydroxydopamine (6-OHDA) was injected into the right striatum of rats. Behavioral evaluations of PD symptoms were employed, including cylinder test and amphetamine-induced rotation test performed at 1 and 2 weeks after 6-OHDA injection. Animals were subsequently euthanized for immunohistochemical investigations. In order to explore neurotrophic and growth factor upregulation induced by SCS, another cohort of rats that received 50 Hz SCS was euthanized at 1 and 2 weeks after lesion for protein assays. Behavioral tests revealed that the number of amphetamine-induced rotations decreased in SCS groups. Immunohistochemically, tyrosine hydroxylase (TH)-positive fibers in the striatum were significantly preserved in SCS groups. TH-positive neurons in the substantia nigra pars compacta were significantly preserved in 50 Hz SCS group. The level of vascular endothelial growth factor (VEGF) was upregulated by SCS at 1 week after the lesion. These results suggest that high cervical SCS exerts neuroprotection in PD model of rats, at least partially by upregulation of VEGF. SCS is supposed to suppress or delay PD progression and might become a less invasive option for PD patients, although further preclinical and clinical investigations are needed to confirm the effectiveness and safety.