David Haines

Antioxidant properties of calcium dobesilate in ischemic/reperfused diabetic rat retina

Calcium dobesilate possesses antioxidant properties and protects against capillary permeability by reactive oxygen species in the rat peritoneal cavity, but whether a similar action can take place in the diabetic rat retina is unknown. We investigated the oral treatment of diabetic rats with calcium dobesilate on the prevention of free radical-mediated retinal injury induced by ischemia/reperfusion (90 min ischemia followed by 3 min and/or 24 h of reperfusion). Streptozotocin-induced diabetic rats were orally treated with 50 and 100 mg/kg of calcium dobesilate for 10 days (n=12 in each group). In the first series of studies, calcium dobesilate was found to significantly reduce the maldistribution of ion content in diabetic ischemic/reperfused rat retina. Thus, in diabetic rats treated with 100 mg/kg/day calcium dobesilate, ischemia/reperfusion provoked: (i) 27.5% increase in retinal Na(+) content compared to 51.8% in the vehicle-treated group (P<0.05), and (ii) 59.6% increase in retinal Ca(2+) content compared to 107.1% in vehicle-treated animals (P<0.05). In the second series of studies, calcium dobesilate was found to significantly protect diabetic rat retina against inhibition of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase activities by ischemia/reperfusion (54% and 41% reduction, respectively, with 100 mg/kg of calcium dobesilate) and also against changes in retinal ATP, reduced glutathione (GSH), and oxidized glutathione (GSSG) contents. In the third series of experiments, rats treated with 100 mg/kg of calcium dobesilate reduced the hydroxyl radical signal intensity to 41% (measured by electron paramagnetic resonance), induced by ischemia/reperfusion in diabetic rat retina. Finally, 100 mg/kg calcium dobesilate significantly reduced retinal edema (measured by the thickness of the inner plexiform layer) in diabetic rats. In conclusion, oral treatment with calcium dobesilate significantly protected diabetic rat retina against oxidative stress induced by ischemia/reperfusion. Whether the antioxidant properties of calcium dobesilate explain, at least in part, its beneficial therapeutic effects in diabetic retinopathy deserves further investigation.

Lymphocyte subpopulations in pregnancy complicated by hypertension

The immune responsiveness of women is altered during pregnancy in order to retain protective properties against disease and at the same time allow tolerance of the fetus. Diseases such as pre-eclampsia (PE) have been suggested to arise as a result of maladaptations in these immune alterations. Here we evaluate the effect of PE on the composition of peripheral blood lymphocyte subpopulations using lymphocyte surface antigen expression. Fifty-four women of various parities with pregnancy-induced hypertension (PIH) (39 non-proteinuric and 14 proteinuric) and matched controls (30 normotensive pregnant women (NTP) and 15 healthy non-pregnant women (NP)) were investigated. Monoclonal antibodies specific for human T lymphocytes and subpopulations: CD2, CD3, CD4, CD8, CD19 and activation markers: CD25, CD45RA, CD45RO, CD54 AND HLA m DR were used and detected using a two-colour fluorescence analysis with an automated flow cytometer. The total number of T lymphocytes: CD2, CD3, CD4, CD8 and CD19 were significantly decreased in PIH particularly PE ( P <0.05). T cells expressing NK surface markers (CD3/CD16 + CD56) and CD4 cells expressing HLA m DR were higher in PE. CD8 + HLA m DR + cells and T-helper cells expressing adhesion molecules) CD4 + CD54 + ) were higher in NTP than in NP and PE ( P <0.05, 0.05). PE is associated with elevated levels of CD4 + HLA m DR + , and CD3 + NK cells but decreased total numbers of T lymphocytes, and the CD3 + CD25 + subpopulation. These findings indicate systemic alterations in maternal immunity associated with the PE state. This feature of the disease may contribute to abnormal adaptation to pregnancy resulting in PE and PIH, promoting adverse outcomes including pregnancy loss.

Decreased Total Numbers of Peripheral Blood Lymphocytes with Elevated Percentages of CD4+CD45RO+ and CD4+CD25+ of T-Helper Cells in Non-Segmental Vitiligo

Vitiligo is a disorder involving progressive skin depigmentation caused by host mediated destruction of melanocytes. Its pathogenesis is known to correlate with elevated levels of activated skin‐infiltrating T lymphocytes and is presumed to be autoimmune in nature. In the present study, we characterize the immunophenotype of peripheral blood T cells from vitiligo patients, with the objective of developing an investigative and diagnostic tool for the disease, using analysis of peripheral blood. Subjects for this investigation included 32 patients diagnosed with non‐segmental vitiligo and 28 age‐and gender‐matched, normal, healthy control participants. Whole venous blood taken from each subject was analyzed using 2‐color flow cytometry for immunologically‐relevant lymphocyte subsets. When compared with healthy control subjects, peripheral blood from individuals with vitiligo was found to have lower total numbers of lymphocytes (p<0.039). Vitiligo patients also had elevated percentages of memory (CD4+CD45RO+) T cells; (p<0.05), but NK‐T cells (CD3+CD16+CD56+) and naive T cells (CD4+CD45RA+) were present at lower total numbers and percentages than in healthy controls (p<0.01 and 0.05 respectively). Blood from severely afflicted subjects exhibited elevated CD3+HLADR+ and CD4+CD45RO+ as well as lower percentages of NK‐T cells (p<0.05) when compared with mild cases. In conclusion, disease‐associated, peripheral blood lymphocyte immunophenotypic profiles of vitiligo patients are consistent with the hypothesis of T cell activation as a major feature of the disorder. These include elevated memory and reduced naive T cell percentages and increased expression of the activation‐associated surface antigen CD25. These changes presumably reflect increased antigen‐mediated activation. Moreover, because a corollary effect is increased activation‐induced cell death (AICD), lower overall lymphocyte counts observed in vitiligo‐afflicted subjects is also expected.

Lymphocyte subpopulation frequency and presence of anti-cardiolipin and anti-nuclear antibodies in peripheral blood of Kuwaiti women experiencing recurrent pregnancy loss.

Recurrent pregnancy loss (RPL) is often associated with elevated levels of serum antiphospholipid antibodies, which contribute to the pathology of the disorder by promoting formation of thromboses, leading to placental infarction and fetal loss. Patients with recurrent pregnancy loss also exhibit pathological alterations in composition and activity of peripheral blood lymphocytes, which may be indicative of an autoimmune processes. This investigation examines the correlation between levels of anticardiolipin antibody (AC) and specific subsets of the lymphocyte repertoire in RPL patients, with the objective of further characterising the immunological basis for RPL. Non-pregnant Kuwaiti women with a history of RPL were subdivided into two cohorts based on presence or absence of elevated plasma antibodies to cardiolipin. Whole blood from these individuals was analysed by flow cytometry for selected lymphocyte subsets and compared with a non-RPL control population. When compared with controls and low AC titre subjects, women with a high AC titre exhibited significantly elevated percentages of pathogenic CD5 + B cells; two categories of activated T cells including CD4 + CD25 + and CD8 + CD25; NK cells and CD3 + NK cells; naive (CD4 + CD45RA + ) cells; and transitional (CD45RO + CD45RA + ) cells. In conclusion, women with elevated levels of AC antibodies possess substantially higher levels of activated T cells and pathogenic B cells, suggesting a fundamental predisposition to immune-mediated rejection of the fetus by these patients. Further characterisation of this phenomenon may allow development of novel intervention methods for management of RPL.Recurrent pregnancy loss (RPL) is often associated with elevated levels of serum antiphospholipid antibodies, which contribute to the pathology of the disorder by promoting formation of thromboses, leading to placental infarction and fetal loss. Patients with recurrent pregnancy loss also exhibit pathological alterations in composition and activity of peripheral blood lymphocytes, which may be indicative of an autoimmune processes. This investigation examines the correlation between levels of anticardiolipin antibody (AC) and specific subsets of the lymphocyte repertoire in RPL patients, with the objective of further characterising the immunological basis for RPL. Non-pregnant Kuwaiti women with a history of RPL were subdivided into two cohorts based on presence or absence of elevated plasma antibodies to cardiolipin. Whole blood from these individuals was analysed by flow cytometry for selected lymphocyte subsets and compared with a non-RPL control population. When compared with controls and low AC titre subjects, women with a high AC titre exhibited significantly elevated percentages of pathogenic CD5+ B cells; two categories of activated T cells including CD4+CD25+ and CD8+CD25; NK cells and CD3+NK cells; naive (CD4+CD45RA+) cells; and transitional (CD45RO+CD45RA+) cells. In conclusion, women with elevated levels of AC antibodies possess substantially higher levels of activated T cells and pathogenic B cells, suggesting a fundamental predisposition to immune-mediated rejection of the fetus by these patients. Further characterisation of this phenomenon may allow development of novel intervention methods for management of RPL.

Effect of Diabetea tea ™ consumption on inflammatory cytokines and metabolic biomarkers in type 2 diabetes patients.

ETHNOPHARMACOLOGICAL RELEVANCE Diabetea tea™ (DT) is an anti-diabetic alternative medicine in some Asian countries. The main constituent of DT is black tea originating from Camellia sinensis that is supplemented by 12 other medicinal plants. Black tea contains a large amount of the flavonoids catechins especially epigallocatechin gallate (EGCG) which has anti-inflammatory and antioxidative capacity. This study was undertaken to evaluate the possible effects of DT intake on inflammatory cytokines, regulatory T cells (Tregs) and metabolic biomarkers in T2DM. MATERIALS AND METHODS The study included 50 patients with T2DM. The patients had received 3 cups (600ml) of DT extract or placebo (PL) extract per day during a period of 12 weeks. Intracellular cytokine expression in peripheral blood mononuclear cell (PBMC) as well as the glycemic and lipid profiles were measured at baseline and after the treatment period. The active constituents of the medicinal plants included in DT were investigated by gas chromatography-mass spectrometry (GC/MS). RESULTS Ingestion of DT suppressed CD4+ T cell expression of IL-1β and Il-8 (p<0.05) and up-regulated the expression of IL-10 and the Treg/IL-17 ratio (p<0.05) which was not shown in PL. A significant decrease in HbA1c and LDL was observed at the end of the study period (p<0.05) in DT. The GC/MS analyses of DT indicated the presence of lupeol, β-Amyrin and β-sitosterol. Also analyses of individual herbs showed the presence of higher levels of lupeol and β-Amyrin in Nuga Ficus bengalensis and β-sitosterol in the Attikka Ficus racemosa, indicating that the active ingredients of DT are concentrated in these two herbs. CONCLUSION The present study provides evidence that DT has hypoglycemic and antihyperlipidemic properties. Interestingly, DT has anti-inflammatory effects. These properties are attributed to the flavonoids, triterpenes and phytosterol contents of the tea. We suggest that DT protects against diabetes complications in the long term.

Parkinson’s disease: Alpha synuclein, heme oxygenase and biotherapeutic countermeasures.

Neurodegenerative disorders have been and remain persistent sources of enormous suffering throughout human history. The tragedy of their impact on human relationships, physical vitality, and fundamental dignity cannot be understated. Parkinsons disease (PD), one of the most common of these terrible illnesses, has a global incidence of approximately two-to-four percent of the human population, along with devastating social and economic impact. The present review analyzes aspects of PD pathophysiology that offer particularly attractive strategies for the development of improved prevention and therapy. The occurrence, symptoms, pathogenesis, and etiology of PD are considered, with focus on how the Alpha synuclein protein, which normally regulates neurotransmitter release, is aggregated by oxidative stressors into toxic inclusions, prominently including Lewy bodies and insoluble fibrils that disrupt the organization of brain areas responsible for motor control. The contribution to a progressively prooxidant tissue environment resulting from interaction between advanced glycation end products (AGEs) and their cognate receptors (RAGEs) is examined here as a significant driver of PD. This review also explores strategies currently being developed by a U.S.-Russian team that may reduce the risk and severity of PD by use of recombinant atoxic derivatives (ad) of botulinum neurotoxins (BoNT/A ad), that traffic inducers of the cytoprotective enzyme heme oxygenase to selected midbrain neurons, at which Alpha synuclein aggregation occurs. Considered together, the topic material presented here provides both researchers and clinicians with a short but concise overview of the current understanding of PD pathology and approaches to biotherapeutic (precision) countermeasures to its onset and progression.

Activity of Paraoxonase/Arylesterase and Butyrylcholinesterase in Peripheral Blood of Gulf War Era Veterans With Neurologic Symptom Complexes or Post-Traumatic Stress Disorder.

Objective: Two groups of Gulf War era veterans, one exhibiting blurred vision, balance problems/dizziness, tremors/shaking, and speech difficulty and a second group with post-traumatic stress disorder (PTSD), but not the neurologic syndrome, were assessed for organophosphate-detoxifying enzyme paraoxonase/arylesterase (PON1) and its Q/R isoforms, butyrylcholinesterase (BuChE) and its U/A isoforms and cytokines. Methods: Defibrinated peripheral blood was evaluated for enzymes and cytokines. Results: Trends toward elevation of Th2 cytokines interleukin-4 (IL-4) and IL-13 were observed in subjects with neurologic syndrome. Neither the activities nor isoforms of the enzyme, the neurologic symptoms, nor PTSD had any relationship to wartime deployment to the theater of combat. Conclusion: The negative outcomes described above suggest that exposure to organophosphates or other agents normally detoxified by PON1 and BuChE may not have contributed significantly to neurologic components of Gulf War Illness.