Volume 19, Issue 1

Activation of the cellular immune system is discussed to be partly responsible in the neurodegenerative process of Parkinson's disease. We determined concentrations of neopterin, of cytokine interleukin-6, and of soluble cytokine receptors sIL-2Rα, sTNF-R75α in plasma and cerebrospinal fluid in controls and patients with vascular parkinsonism and idiopathic Parkinson's disease diagnosed according to published clinical diagnostic criteria, to examine if the cellular immune system is activated locally or peripherally or both. Our results show no activation in idiopathic Parkinson's disease and controls, but a significant increased activation in vascular parkinsonism, where concomitant signs of cerebrovascular disease are present.

Neural tube defects (NTDs) including spina bifida, anencephaly and encephalocele are among the most common birth defects, with high associated mortality and morbidity. There are no data concerning the incidence, associated anomalies, treatment and outcome of NTDs in Algeria. The objective of this study is to analyse data on NTD cases from 2004-2006 at Sétif Hospital, a hospital with 8,000-10,000 deliveries annually. A retrospective chart review of patients with NTDs was performed, who were born at Sétif Hospital 2004-2006. During the 3 year period we examined, there were 215 patients with NTDs treated in the Sétif Hospital. The incidence of NTD is 7.5 per 1,000 births. The sex distribution was not equal among NTD cases, 126 (58.6%) females, 88 (40.9%) males and one (0.5%) unidentified sex. Among all NTD cases, there where 122 (56.7%) with spina bifida, 69 (32.1%) with anencephaly, 1 (0.5%) with encephalocele and 23 (10.7%) with anencephaly and spina bifida. Hundred and seventeen (54.4%) cases died in utero and 4 cases (1.9%) unknown. The rate of consanguinity among all NTD cases was 13% (28/215). The rate of affected newborns was highest in mothers aged 31-35 years (21.9%). The peak prevalence was in June (15.8%). A half of NTDs were spina bifida and there was a high rate of mortality. This study demonstrates that NTD represents a significant public health problem in Algeria. In Algeria there were no population-wide educational campaigns about folic acid or its association with the prevention of birth defects. Public health interventions aimed at increasing the periconceptional consumption of folic acid should be implemented or enhanced to reduce the incidence of NTDs in Algeria.

Recently, we have observed in patients with ovarian carcinoma an association between intestinal permeability and prognosis and a correlation between urinary neopterin and parameters of intestinal permeability. In order to examine prognostic significance of intestinal permeability in a different group of patients, we have retrospectively analyzed pretreatment parameters of gastrointestinal permeability and urinary neopterin in 21 consecutive patients with metastatic colorectal carcinoma treated with the combination of cetuximab, irinotecan, leucovorin and 5-fluorouracil. Neopterin was determined by high-performance liquid chromatography, and gastrointestinal permeability was assessed by measuring, using capillary gas chromatography, urinary sucrose, lactulose, xylose, mannitol and sucralose after oral challenge. Pretreatment sucrose/mannitol ratio equal or above 0.04 (median survival 10.6 vs. 18.4 months; p = 0.03), sucrose/xylose equal or above 0.02 (12.1 vs. 19 months; p = 0.04) and urinary neopterin equal or above 220 μmol/mol creatinine (10.6 vs. 18.4 months; p = 0.02) were indicative of poor survival. A significant correlation was observed between urinary neopterin and sucrose/xylose ratio (rs = 0.57, p = 0.007), while correlation between urinary neopterin and sucrose/mannitol ratio (rs = 0.38, p = 0.096) was of borderline significance. In conclusion, present data demonstrate that gastrointestinal permeability is associated with systemic immune activation and may be of prognostic significance in patients with metastatic colorectal carcinoma.

To further evaluate the clinical usefulness of serum neopterin measurement as a parameter monitoring disease activity in children with ulcerative colitis, serum neopterin concentrations were evaluated using immunoenzyme assay (ELISA) in 48 patients suffering from ulcerative colitis with different disease activity. Statistically significant differences in serum neopterin concentration depending on disease activity (according to Truelove-Witts score) as well as statistically significant positive correlation between these variables were observed. We conclude that serum neopterin measurement can be clinically valuable as the parameter monitoring disease activity in children with ulcerative colitis.

Angiogenesis plays a crucial role in tumor progression. Prominent among angiogenic factors is vascular endothelial growth factor (VEGF). VEGF is produced by cancer cells as well as by the cells infiltrating tumor stroma, mainly macrophages. Macrophage activation may be assessed by measuring serum or urinary neopterin. Systemic inflammatory response could be evaluated by measuring serum C-reactive protein concentrations. The aim of the present study was to examine the effect of a regimen combining dose dense combination of doxorubicin and cyclophosphamide with sequential weekly paclitaxel on plasma VEGF, urinary neopterin and serum C-reactive protein concentrations. Thirty-four female patients with histologically verified breast carcinoma treated with dose-dense regimen combining doxorubicin and cyclophosphamide with sequential weekly paclitaxel administration were studied. Plasma VEGF was measured by enzyme-linked immunosorbent assay. Urinary neopterin was determined by high performance liquid chromatography. Compared to baseline plasma VEGF was significantly decreased one week after the start of therapy. VEGF concentrations subsequently increased, but this increase was significant compared to baseline only at week 16. Urinary neopterin was significantly increased compared to baseline at every visit with the exception of visits 12 and 20 at which the significance was borderline. Serum C-reactive protein was increased compared to baseline only at visits 4, 6 and 8. A positive correlation was observed between plasma VEGF and serum C-reactive protein at baseline and at visits 5 and 19. Significant correlations were observed between serum C-reactive protein and urinary neopterin at visits 6, 7, 9, 11, 14, 15 and 17. In conclusion, only minor changes in plasma VEGF and serum C-reactive protein were observed during dose-dense chemotherapy. In contrast, urinary neopterin was increased throughout the course of treatment. Correlations between VEGF and C-reactive protein and between Creactive protein and urinary neopterin were observed only at some time points.

N 2 -( N , N -Dimethylaminomethylene)-3-[2-(4-nitrophenyl)ethyl]-1',2'-di- O -(trimethylsilyl)biopterin ( 4 ) was prepared from biopterin ( 1a , 86% overall yield) in 5 steps. Glycosylation of 4 with 1,2,3,5-tetra- O -acetyl-β-D-ribofuranose ( 5a ) and its 2,3,5-tri- O -benzoyl analog ( 5b ) respectively afforded the corresponding 2'- O -(2,3,5-tri- O acetyl- and 2,3,5-tri- O -benzoyl-β-D-ribofuranosyl)biopterin derivatives ( 6a , 42% and 6b , 60%) as major products. Removal of the protecting groups of 6b provided 2'- O -(β-D-ribofuranosyl)biopterin ( 1c , 87% overall yield) in 3 steps.

Acute infectious diseases of the respiratory tract are regularly associated with increased concentrations of neopterin in serum and/or urine. Most likely, the pteridine compound is not only a marker of an activated cellular immune system but may exert distinct biochemical functions in the process of infections as well. In response to viral contact, macrophages located in the nasal mucosa may represent a source for neopterin in the nasal cavity with potential hazardous effects on ciliary beat frequency (CBF), thus promoting chronic infectious processes. The aim of the present study was to investigate the effects of neopterin at different concentrations (10 nM, 100 nM, and 100 μM) on CBF in human nasal epithelial cells in vitro . Samples were taken from the inferior nasal turbinate and incubated with neopterin dissolved in either aqua destillata or in sodium chloride (0.9%) at the given amounts for 2, 5, 10, and 20 min. In a preliminary set of experiments, neopterin inhibited CBF following the 5 and 10 min. incubation protocol, respectively. However, analyses of pooled data from 28 experiments using sodium chloride (0.9%) as solvent could not confirm these findings: in no setting a significant reduction of CBF was detected at the end of the 20 min. experimental procedure. Therefore, we conclude that neopterin most likely does not affect the mucociliary clearance defense mechanisms in the course of infections of the nasal respiratory tract.

Increased urinary or serum concentrations of neopterin have been reported in cancer patients, but less is known about neopterin concentrations in cerebrospinal fluid (CSF). CSF neopterin was determined with radioimmunoassay in 64 patients. CSF neopterin concentrations in patients with tumors were significantly higher compared to patients with predominantly peripheral infections (Lyme borreliosis and herpes simplex infection) and no infectious, inflammatory or neoplastic disorder, and significantly lower compared to patients with meningitis or encephalitis. Among patients with tumors, CSF neopterin was significantly higher in patients with non- Hodgkin lymphoma (NHL) compared to other tumors. The difference between patients with tumors other than NHL and predominantly peripheral infections was of borderline significance, and a significant difference was observed between patients with tumors other than NHL and no disorder. CSF neopterin was significantly higher in patients with NHL compared to patients with predominantly peripheral infections, multiple sclerosis or polyneuropathy and no disorder, and no difference was evident compared to patients with meningitis or encephalitis. In conclusion, among patients with tumors, high CSF neopterin may suggest the diagnosis of NHL.

Tetrahydrobiopterin (BH 4 ) content in the pancreas from GK (Goto-Kakizaki) rats as a type II diabetic model was markedly decreased compared to Wistar rats as a healthy control. Moreover, insulin stimulated BH 4 synthesis in a hamster pancreatic β-cell line, HIT-T15 cells. Therefore, in diabetic condition, the reduction of insulin action is likely to lead to the low levels of BH 4 content in pancreatic β-cells. In this study, we examined the effects of the decrease in BH 4 content on insulin secretion by L-arginine (L-Arg) or glucose using HIT-T15 cells. Cytosolic calcium concentration ([Ca 2+ ] i ) in HIT-T15 cells was increased by L-Arg. Under the low BH 4 content using 2,4- diamino-6-hydroxypyrimidine (DAHP), a selective inhibitor of BH 4 synthesis, L-Arg-induced both Ca 2+ response and insulin secretion were stimulated. These stimulating effects were recovered by BH 4 content recovering, using sepiapterin, a precursor of BH 4 biosynthesis. By contrast, glucose-induced Ca 2+ response was not affected by the BH 4 content. These results suggest that the decrease of BH 4 content in β-cells may stimulate insulin secretion by L-Arg, but not by glucose, under diabetic conditions.

Nigella sativa , commonly known as black cumin seed, belongs to the botanical family of Ranunculaceae. The active antioxidant components of Nigella sativa display a remarkable array of biochemical, immunological and pharmacological actions, including bronchodilatory, anti-inflammatory, antibacterial, hypoglycaemic, antitumoural and immunopotentiating effects. Effects of Nigella sativa seeds extracts were investigated in freshly isolated human peripheral blood mononuclear cells stimulated with the mitogens phytohaemagglutinin and concanavalin A in vitro . Tryptophan degradation and neopterin production were monitored in culture supernatants, both these immunobiochemical pathways are induced by pro-inflammatory cytokine interferon-γ. Compared to unstimulated cells, the mitogens enhanced degradation of tryptophan and production of neopterin. Nigella sativa seeds extracts significantly suppressed both pathways in a dose-dependent way. Suppression of tryptophan degradation and neopterin formation by Nigella sativa seeds extracts demonstrates an inhibitory influence on activated T-cells and macrophages. Data are in line with an anti-inflammatory activity of the extracts.

The profiles of unconjugated pteridines such as neopterin and biopterin and of tryptophan metabolism change in many pathologic conditions such as rheumatoid arthritis, malignancies and autoimmune diseases and are related to the release of pro-inflammatory cytokines. However, studies on potential effects of drugs are very limited. This study investigates whether meloxicam, a non-steroidal anti-inflammatory drug, may cause any alteration of the pteridine pathway and tryptophan metabolism in 22 patients who admitted to the Physical and Rehabilitation Medicine outpatient clinic in the Hacettepe University Hospital and suffering from various musculoskeletal pain conditions without systemic inflammation. Urine concentrations of neopterin, biopterin and xanthopterin, and serum concentrations of neopterin, tryptophan, and kynurenine, and the activity of dihydropteridine reductase were measured at the beginning of the therapy and after a 15 days treatment with meloxicam. Average urine concentrations (± S.E.M.) of pterins before therapy (neopterin: 263 ± 15.6 μmol/mol creatinine, biopterin: 72.4 ± 13.4 μmol/mol creatinine, and xanthopterin: 675 ± 93.0 μmol/mol creatinine) were not changed during meloxicam therapy (neopterin: 230 ± 30.7 μmol/mol creatinine = 88% of baseline, biopterin 115 ± 26.5 μmol /mol creatinine = 159% of baseline, and xanthopterin 684 ± 88.0 μmol/mol creatinine = 101% of baseline; all differences not significant). The activity of dihydropteridine reductase was 6.02 ± 0.21 nmol/cytochrome C reduced/min/5 mm disc before and 6.28 ± 0.18 nmol/cytochrome C reduced/min/5 mm after treatment (= 104% of baseline; p = 0.088). Serum concentrations of neopterin 6.04 ± 0.33 nmol/L before treatment increased to 6.89 ± 0.48 nmol/L after treatment (= 114% of baseline; p <0.05, paired rank test). Likewise serum kynurenine concentrations increased from 1.52 ± 0.13 μmol/L to 1.87 ± 0.14 μmol/L after treatment (= 123% of baseline; p <0.01). There was a significant correlation between neopterin and kynurenine concentrations which corresponds with their common background of production, namely immune activation. However, also the mean tryptophan concentration in pretreatment samples 51.4 ± 3.34 increased to 59.3 ± 3.34 μmol/L post-treatment (= 115% of baseline; p <0.05). The change of kyn/trp was minor (at baseline: 30.4 ± 2.01, post-treatment: 32.2 ± 2.47 μmol/mmol; = 106% of baseline, not significant). Our findings show an influence of meloxicam treatment on neopterin and tryptophan metabolism in patients. However, significant differences were only found in serum but not in urine of patients. In serum, all marker concentrations increased including tryptophan and kynurenine.

Immune system activation has been observed during endurance exercise, but its relevance is largely unclear. We evaluated urinary neopterin excretion in an athlete competing in the Race Across America (RAAM), to determine whether neopterin excretion would indicate that immune system activation occurs during extreme endurance sport. Urinary samples were collected at the day before the race, during the whole RAAM, and, without a physical strain, seven days after the race. Neopterin normalized to creatinine concentration was determined by reversed-phase high-pressure liquid chromatography (HPLC). Data were analysed by repeated-measured analysis of variance (ANOVA). In the athlete, urinary neopterin concentration started to increase consistently after the start of the race until day four, followed by a decline thereafter, reaching values close to the starting value. The lowest average neopterin concentration was observed at day seven; this concentration was significantly lower than mean values at days 2- 6 (all p <0.05). Comparing the power output (Watt) with the neopterin concentrations at the same time point revealed a significant correlation (r s = 0.333; p <0.05). A comparison of average daily urinary neopterin excretion mean values between the test and control person showed significant differences at all time points, except for the specimen obtained at day seven. This pilot study supports the hypothesis that extreme long endurance strain at low intensities leads to an activation of the immune system. Neopterin levels could be a convenient tool to assess the immune system activation induced by training in athletes.

Current literature lists the lactam and lactim tautomers as the only major contributors to aqueous pterin structures. Density functional theory calculations were used to determine whether there are other significant neutral tautomers of pterin participating in photochemical and biological systems other than the lactam and lactim forms in aqueous media. Calculations showed that the lactam tautomer is the lowest energy structure while the lactim structure is higher in energy than expected (∼6 kcal/mol) compared to the lactam structure. Three other neutral pterin structures were calculated to be less than ∼4 kcal/mol above the most stable lactam and therefore should also be considered as structures which possibly play an important role in chemical and biological pterin systems.