The efficacy of the diode laser at 800-980 nm as an aid to non-surgical therapy in periodontitis treatment: a review of literature.

The aim of this literature review is to assess the effectiveness of diode laser at a wavelength of 800-980 nm in addition to non-surgical periodontal therapy in periodontitis treatment. The authors performed an electronic research on Pubmed inserting as keywords: (laser OR laser therapy OR diode laser) and (periodontitis OR periodontal disease). The field has been narrowed to select only Randomized controlled clinical trials (RCT) performed from 2010 to 2020. The result of this research was 84 articles, of which eight were included in the review because they respect the inclusion criteria. The clinical, immunological, and microbiological parameters studied in the various clinical random trials were analysed. It has been shown that four out of eight studies have achieved greater benefits, in terms of clinical parameters, with the use of diode laser compared to Scaling and Root Planing. However, the greater increase in clinical parameters in diode laser-treated patients compared to the control group was mainly detected in the short term rather than in the long term. In terms of microbiological parameters, no improvement was detected after six months. Only one study reported six-month improvements in immunological parameters in patients treated with DL compared to the Scaling and Root Planing only group. In conclusion, considering the limitations of this review of literature, there is no evidence that the diode laser at 800-980 nm in addition to non-surgical periodontal therapy is more effective than SRP alone in the long term.

Multishell Diffusion MRI-Based Tractography of the Facial Nerve in Vestibular Schwannoma.

BACKGROUND AND PURPOSE: Tractography of the facial nerve based on single-shell diffusion MR imaging is thought to be helpful before surgery for resection of vestibular schwannoma. However, this paradigm can be vitiated by the isotropic diffusion of the CSF, the convoluted path of the facial nerve, and its crossing with other bundles. Here we propose a multishell diffusion MR imaging acquisition scheme combined with probabilistic tractography that has the potential to provide a presurgical facial nerve reconstruction uncontaminated by such effects. MATERIALS AND METHODS: Five patients scheduled for vestibular schwannoma resection underwent multishell diffusion MR imaging (b-values = 0, 300, 1000, 2000 s/mm2). Facial nerve tractography was performed with a probabilistic algorithm and anatomic seeds located in the brain stem, cerebellopontine cistern, and internal auditory canal. A single-shell diffusion MR imaging (b-value = 0, 1000 s/mm2) subset was extrapolated from the multishell diffusion MR imaging data. The quality of the facial nerve reconstruction based on both multishell diffusion MR imaging and single-shell diffusion MR imaging sequences was assessed against intraoperative videos recorded during the operation. RESULTS: Single-shell diffusion MR imaging-based tractography was characterized by failures in facial nerve tracking (2/5 cases) and inaccurate facial nerve reconstructions displaying false-positives and partial volume effects. In contrast, multishell diffusion MR imaging-based tractography provided accurate facial nerve reconstructions (4/5 cases), even in the presence of ostensibly complex patterns. CONCLUSIONS: In comparison with single-shell diffusion MR imaging, the combination of multishell diffusion MR imaging-based tractography and probabilistic algorithms is a more valuable aid for surgeons before vestibular schwannoma resection, providing more accurate facial nerve reconstructions, which may ultimately improve the postsurgical patient's outcome.

Apheresis treatment of cryoglobulinemic vasculitis: A multicentre cohort study of 159 patients.

OBJECTIVE: To assess the effectiveness of apheresis therapy (AT) in treating the clinical manifestations of patients with complicated cryoglobulinemic vasculitis (CV). METHODS: A retrospective cohort study of 159 CV patients attending 22 Italian Centers who underwent at least one AT session between 2005 and 2015. The response to AT was evaluated on the basis of a defined grading system. RESULTS: Peripheral neuropathy was the most frequent clinical condition leading to AT. Therapeutic plasma exchange was used in 70.4% of cases. The outcome of AT was rated very good in 19 cases, good in 64, partial/transient in 40, and absent/not assessable in 36. Life-threatening CV-related emergencies and renal impairment independently correlated with failure to respond to AT. The independent variables associated with an increased risk of death were age at the time of the first AT session, multi-organ life-threatening CV, the presence of renal impairment and failure to respond to AT. The time-dependent probability of surviving until CV-related death in the second year was 84%, with an AHR in patients with absent/not assessable response to AT of 11.25. CONCLUSION: In this study AT is confirmed to be a safe procedure in patients with CV. Early AT should be considered in patients with severe CV, especially in cases with impending renal involvement, in order to prevent irreversible kidney damage. Although its efficacy in patients with multi-organ failure is limited, AT is the only treatment that can rapidly remove circulating cryoglobulins, and should be considered an emergency treatment.

Frequency of psychological alterations in primary antiphospholipid syndrome: preliminary study.

Objectives To detect the frequency of psychological alterations in primary antiphospholipid syndrome patients. Methods Thirty-six primary antiphospholipid syndrome patients were analyzed by a psychological interview using a standard protocol and review of medical charts. Clinical manifestations, associated comorbidities, antiphospholipid antibodies, and treatment were also evaluated. Results The mean age was 44.2 ± 10.8 years, 29 (80%) were women and 29 (80%) were of Caucasian race. The mean duration of disease was 7.3 ± 5.2 years. The frequency of the presence of psychological alterations was 97.1%. Family dependence was observed in 14 (40%), memory loss in 12 (34.3%), social losses in 12 (34.3%), sexual limitations in seven (20%), sadness in six (17.1%), severe speech limitation in four (11.4%), anxiety in three (8.6%), learning difficulty in two (5.7%), generalized phobia in two (5.7%), suicide ideation in one (2.6%), agoraphobia in one (2.6%), and obsessive-compulsive disorder in one (2.6%). Conclusion This study demonstrated that almost all primary antiphospholipid syndrome patients have psychological alterations. These data reinforce the need for psychological evaluation in primary antiphospholipid syndrome patients.

Impact of the Ile105Val Polymorphism of the Glutathione S-transferase P1 (GSTP1) Gene on Obesity and Markers of Cardiometabolic Risk in Young Adult Population.

The aim of the study was to investigate the association between Glutathione S-transferase P1 (GSTP1) gene polymorphism with obesity and markers of cardiometabolic risk. A cross-sectional study was carried out in individuals aged≥18 and ≤30 years. The study included 54 normal weight, 27 overweight and 68 obese volunteers. Anthropometric measurements and biochemical parameters were evaluated, the DNA was extracted from blood samples and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to measure GSTP1 Ile105Val gene polymorphism of the study participants. Also, biochemical analysis and hormone assays were carried out. A positive association between GSTP1 polymorphism and obesity was observed on subjects carrying at least one G allele (AG and GG). GG genotype was found only in the obese group. The G allele carriers presented 2.4 times higher chance of obesity when compared to those with the AA genotype. These results were independent of sex and age. We suggest that despite a study in population regional (south of Brazil), the GSTP1 gene polymorphism may play a significant role in the increase of susceptibility of obesity and contribute to identify the cardiovascular risk in young adults.

Rutin restores adenosine deaminase activity in serum and the liver and improves biochemical parameters in streptozotocin-induced diabetic rats / Rutina restaura a atividade da Adenosina desaminase no soro e no fígado e melhora os parâmetros bioquímicos em ratos diabéticos induzidos por estreptozotocina

ABSTRACT denosine deaminase (ADA) is a critical control point in the regulation of adenosine levels. This study aimed to investigate the effects of a polyphenolic flavonoid, rutin, on the activity of ADA in serum, the cerebral cortex, liver, kidney, and biochemical parameters in diabetic rats. The animals were divided into four groups (n=6) for the following treatments: control; diabetic (streptozotocin 55 mg/kg); diabetic with rutin (100 mg/kg/day); diabetic with glibenclamide (10 mg/kg/day). After 30 days, ADA activity and biochemical parameters were analyzed. The ADA activity in the serum was significantly elevated in the diabetic group compared to the control group (p<0.01). The treatment with rutin prevented the increase in ADA activity in the STZ-induced rats when compared to control group. Our data showed that rutin reduced glucose, LDL levels, and hepatic enzymes in comparison with the control group. These results demonstrate that the increase of ADA activity observed in diabetic rats may be an important indicator of the immunopathogenesis of hyperglycemic disorders and suggest that rutin is important for regulating the enzymatic activities associated with immune, hyperglycemic, and inflammatory response in diabetes mellitus.

RESUMO A Adenosina desaminase (ADA) representa um ponto de controle crítico na regulação dos níveis de adenosina. A rutina, um flavonóide polifenólico presente em muitas plantas, foi testado para verificar a sua influência na atividade da ADA no soro, córtex cerebral, fígado rim e parâmetros bioquímicos em ratos diabéticos. Os animais foram divididos em quatro grupos cada grupo com 6 animais), tal como: controle; diabética (estreptozotocina 55 mg/kg); diabética + rutina (100 mg/kg/dia); diabético + glibenclamida (10 mg/kg/dia). Após 30 dias foram analisadas a atividade da ADA sérica e tecidual e parâmetros bioquímicos. A atividade de ADA no soro foi significativamente elevada no grupo diabético quando comparado ao grupo controle (p<0,01). O tratamento com Rutina preveniu o aumento na atividade da ADA nos ratos diabéticos, quando comparado com o grupo controle. Os resultados mostraram que a rutina reduziu a glicose, os níveis de LDL e as enzimas hepáticas, em comparação com o grupo controle. Estes resultados mostram que o aumento da atividade da ADA observado em ratos diabéticos pode ser um indicador importante da imuno-patogênese de perturbações hiperglicêmicas e sugerem que a Rutina é importante na regulação das atividades enzimáticas associadas com a resposta imunitária, hiperglicêmica e inflamatória no Diabetes mellitus.

In Vitro Effects of Resin Infiltration on Enamel Erosion Inhibition.

Resin-based materials that show promising effects for preventing the progression of erosion have been studied. This in vitro study evaluated the effects of applying resin-based materials, including resin infiltration, on previously eroded enamel subjected to erosive challenges. The influence of enamel surface etching prior to application of the material was also studied. Bovine enamel blocks were immersed in hydrochloric acid (HCl), 0.01 M (pH 2.3), for 30 seconds in order to form a softened erosion lesion. The blocks were then randomly divided into nine groups (n=12) and treated as follows: C = control without treatment; Hel = pit & fissure resin sealant (Helioseal Clear); Adh = two-step self-etching adhesive system (AdheSe); Tet = two-step conventional adhesive system (Tetric N-bond); and Inf = infiltrant (Icon). The Helno, Adhno, Tetno, and Infno groups received the same materials without (or with no) surface conditioning. The depth of the material's penetration into softened erosion lesions was qualitatively analyzed using reflection and fluorescence confocal microscopy. After application of the materials, the blocks were immersed in HCl for two minutes; this step was followed by immersion in artificial saliva for 120 minutes four times a day for five days (erosive cycling). Both the enamel alteration and material thickness were analyzed using profilometry, and the results were submitted to Kruskal-Wallis and Dunn tests (p>0.05). Images from the confocal microscopy showed minimal penetration of Adh/Adhno and deep penetration of Inf/Infno into the erosive lesions. The groups Hel, Adh, Inf, Tetno, and Infno resulted in the formation of a layer of material over the enamel, which was effective in inhibiting the progression of erosion. In conclusion, the infiltrant, with or without etching, was able to penetrate and protect the enamel against dental erosion. The other resin-based materials, except for the two-step conventional adhesive, were able to penetrate and inhibit the progression of erosive lesions only when they were applied after enamel etching.

Effect of fluoride varnish supplemented with sodium trimetaphosphate on enamel erosion and abrasion: an in situ/ex vivo study.

OBJECTIVE: To evaluate the effect of fluoride (F) varnishes supplemented or not with sodium trimetaphosphate (TMP) on enamel erosive wear followed or not by abrasion in situ. METHODS: Ten volunteers were selected and randomly divided into four groups, according to the varnishes tested: placebo (no F or TMP), 5% NaF (positive control), 2.5% NaF and 2.5% NaF/5% TMP. Enamel blocks (n=4) were mounted in palatal devices and received an application of each test varnish, following a double-blind, crossover protocol. After 6h, varnishes were completely removed and the blocks were subjected to erosive challenges by ex vivo immersion in citric acid (5 min, 4×/dia, 5 days). Following, half of the blocks were subjected to abrasion by brushing with a placebo dentifrice slurry for 15s. Enamel wear (µm), surface hardness (SHf) and cross-sectional hardness (ΔKHN) were assessed after each experimental period. Results were analyzed by ANOVA, Student-Newman-Keuls's test and Pearson correlation coefficient (p<0.05). RESULTS: The fluoride varnish supplemented with TMP promoted significantly lower wear and ΔKHN when compared to the other groups after erosive challenges, followed or not by abrasion (p<0.05). As for (SHf) the fluoride varnish supplemented with TMP promoted similar results to the 5% NaF product, being significantly higher than the remaining groups after erosive and erosive+abrasive challenges (p<0.05). CONCLUSION: TMP significantly enhanced the effects of F on enamel wear after erosive challenges, followed or not by abrasion.

Differential effects of organic and inorganic selenium compounds on adenosine deaminase activity and scavenger capacity in cerebral cortex slices of young rats.

Selenium (Se) has anti-inflammatory and antioxidant properties and is necessary for the development and normal function of the central nervous system. This study was aimed to compare the in vitro effects of 3-methyl-1-phenyl-2-(phenylseleno)oct-2-en-1-one (C21H2HOSe; organoselenium) and sodium selenate (inorganic Se) on adenosine deaminase (ADA) activity, cell viability, lipid peroxidation, scavenger of nitric oxide (NO) and nonprotein thiols (NP-SH) content in the cerebral cortex slices of the young rats. A decrease in ADA activity was observed when the slices were exposed to organoselenium at the concentrations of 1, 10 and 30 µM. The same compound showed higher scavenger capacity of NO than the inorganic compound. Inorganic Se was able to protect against sodium nitroprusside-induced oxidative damage and increased the NP-SH content. Both the compounds displayed distinctive antioxidant capacities and were not cytotoxic for the cerebral cortex slices in the conditions tested. These findings are likely to be related to immunomodulatory and antioxidant properties of this compound.

Static and dynamic efficiency of irreversible health care investments under alternative payment rules.

The paper studies the incentive for providers to invest in new health care technologies under alternative payment systems, when the patients' benefits are uncertain. If the reimbursement by the purchaser includes both a variable (per patient) and a lump-sum component, efficiency can be ensured both in the timing of adoption (dynamic) and the intensity of use of the technology (static). If the second instrument is unavailable, a trade-off may emerge between static and dynamic efficiency. In this context, we also discuss how the regulator could use control of the level of uncertainty faced by the provider as an instrument to mitigate the trade-off between static and dynamic efficiency. Finally, we calibrate the model to study a specific technology and estimate the cost of a regulatory failure.

Hypoxic-ischemic brain injury stimulates inflammatory response and enzymatic activities in the hippocampus of neonatal rats.

Brain damage from neonatal hypoxia-ischemia (HI) plays a major role in neonatal mortality and morbidity. Using the Rice-Vannucci model of HI in rats, we verified that 8 days after HI injury, adenosine deaminase (ADA), N-acetyl-glucosaminidase (NAG) and myeloperoxidase (MPO) activities increased in the left hemisphere hippocampus (HI group); however, the activity of 5'-nucleotidase (5'NT) remained unchanged. In the hematoxylin-eosin analysis (HE), we detected selective and delayed degeneration of hippocampal pyramidal neurons and astroglial reaction accompanied by glial fibrillary acidic protein (GFAP)-positive and vimentin-positive in the immunohistochemistry analysis in the HI group compared with the control group. We observed the selective necrosis of neurons, vascular endothelial proliferation and inflammatory response accompanied by the increase of the key enzyme of adenosine metabolism in the HI group. The increase of ADA activity, despite the 5'NT activity was not altered, indicates the predominance of ADA activity in the postischemic homeostasis of extra cellular adenosine. The presence of leukocytes into the ischemic areas displays the possible importance of the neutrophil-macrophages associated with the increase of MPO and NAG activities 8 days after HI. These findings may contribute to the evaluation of some consequences of the damage caused by neonatal HI.

Protective effects of Syzygium cumini seed extract against methylmercury-induced sistemic toxicity in neonatal rats.

Syzygium cumini (L.) Skeels (Sc) belongs to the medicinal plants with an important source of phenolic compounds. Sc has been shown to possess antioxidant and anti-inflammatory properties. Methylmercury (MeHg), a highly toxic environmental pollutant, induces oxidative stress and dysfunction in many cell types. This study was aimed to evaluate the effect of aqueous seed extract of Sc (ASc) on MeHg-induced toxicity in rats. Two-day-old rats (P2) received a single dose of MeHg (10 mg/kg) and two doses of ASc (0.9 mg/kg) per os. After two days, the effects of the treatment were investigated in the cerebral cortex, hippocampus, kidney, liver and urine samples. Our results demonstrated that N-acetyl-ß-D: -glucosaminidase (NAG) activity in the kidney and urine, the lipid peroxidation levels in the liver and kidney samples, as well as the adenosine deaminase (ADA) activity in the hippocampus, kidney and liver were higher in MeHg-group when compared to the control group. The administration of ASc reverted the toxic effects of MeHg. It is noteworthy to observe that the main compounds present in the ASc, as gallic acid (the major component), chlorogenic acid and rutin, might be the responsible for such benefit, since they were found to display antioxidant properties.

Assessment of uric acid and lipid peroxidation in serum and urine after hypoxia-ischemia neonatal in rats.

The aim of this study was to evaluate urinary uric acid (UA) and lipid peroxidation levels, plasma myeloperoxidase (MPO) and adenosine deaminase (ADA) activities, and serum UA in neonatal rats subjected to hypoxia-ischemia neonatal HI model. The relevance of the findings is the fact that urinary lipid peroxidation and UA levels were significantly higher in 8 days in HI group when compared with the control, returning to baseline levels 60 days after HI. Hence, being an indication of purinic degradation during these first days post-HI. Furthermore, the higher levels of malondialdehyde (MDA) in urine in this period may be related to inadequate scavenging abilities of the immature nervous system and being noninvasive it may suggest the use of urinary MDA measurement as a marker for lipid peroxidation after HI insult. In application terms, these findings can help develop therapeutic interventions as soon as 8 days after HI.

Effect of different fluoride concentrations of experimental dentifrices on enamel erosion and abrasion.

It has been suggested that fluoride products are able to reduce erosive tooth wear. Thus, the purpose of this in vitro study was to evaluate the effect of dentifrices with different fluoride concentrations as well as of a low-fluoridated dentifrice supplemented with trimetaphosphate (TMP) on enamel erosion and abrasion. One hundred twenty bovine enamel blocks were assigned to the following experimental dentifrices: placebo, 1,100 microg F/g, 500 microg F/g plus 3% TMP and 5,000 microg F/g. The groups of enamel blocks were additionally subdivided into conditions of erosion (ERO) and of erosion plus abrasion (ERO + ABR). For 7 days, the blocks were subjected to erosive challenges (immersion in Sprite 4 times a day for 5 min each time) followed by a remineralizing period (immersion in artificial saliva between erosive challenges for 2 h). After each erosive challenge, the blocks were exposed to slurries of the dentifrices (10 ml/sample for 15 s). Sixty of the blocks were additionally abraded by brushing using an electric toothbrush (15 s). The alterations of the enamel were quantified using the Knoop hardness test and profilometry (measurements in micrometers). The data were analyzed using a 2-way ANOVA test followed by a Bonferroni correction (p < 0.05). In in vitro conditions, the 5,000 microg F/g and 500 microg F/g plus 3% TMP dentifrices had a greater protective effect when compared with the 1,100 microg F/g dentifrice, under both ERO and ERO + ABR conditions. The results suggest that dentifrices alone are not capable of completely inhibiting tooth wear.

Evaluation of cerebrospinal fluid adenosine deaminase activity in HIV-seropositive subjects and its association with lactate dehydrogenase and protein levels.

The purpose of this study was to investigate the role of ADA as additional marker of HIV infection as well as its association with other biochemical markers. This study included 55 patients, 26 being diagnosed as HIV positive and 29 patients diagnosed as HIV negative. Glucose, total protein, lactate dehydrogenase, and adenosine deaminase (ADA) activity were measured on cerebrospinal fluid (CSF). ADA activity on CSF was statistically different in HIV-seropositive subjects compared with HIV-negative subjects. The sensitivity and specificity of ADA activity on CSF was 50 and 82.76%, respectively. ADA activity was positively correlated with lactate dehydrogenase and protein in patients with HIV positive and it was negatively correlated with glucose levels. ADA determination in CSF could add information about inflammatory processes in patients with HIV infection.

Allium sativum L. extract prevents methyl mercury-induced cytotoxicity in peripheral blood leukocytes (LS).

Adenosine deaminase (ADA) is involved in purine metabolism and plays a significant role in the immune system. The focus of this investigation was to examine the effects of low concentrations of organic mercury on ADA activity in human leukocytes and to investigate the relationship between these effects and cell death. We have examined the protective potential effects of Allium sativum extract (GaE) against Methylmercury (MeHg)-induced cytotoxic effects on human leucocytes under in vitro conditions. MeHg (0.05-10 microM) significantly decreased leukocyte viability (58.97% for MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) and 51.67% for Alamar Blue (AB) and this decrease was positively correlated to the MeHg-induced inhibition of ADA activity. N-acetylcysteine (NAC) and GaE prevented both the MeHg-induced cytotoxic effects on leukocytes according to MTT and AB assays and the effects on the ADA activity. The present results suggest that the protective effects of GaE against MeHg-induced leukocyte damage is related to the removal of oxidant species generated in the presence of MeHg due to the antioxidant efficacy of garlic constituents. It is important to point out that the intense presence of ADA in Leukocyte suspension (LS) highlights the relevant effects in the immune system and in vitro cytotoxicity of MeHg exposure.

Decrease of adenosine deaminase activity and increase of the lipid peroxidation after acute methotrexate treatment in young rats: protective effects of grape seed extract.

The methotrexate (MTX) is an anti-folate used to treat cancer and some inflammatory diseases. The efficacy of MTX is often limited by its severe toxicity. The present study was undertaken to determine whether Grape seed (Cabernet Sauvignon) extract (GSE) could ameliorate the MTX-induced oxidative injury and the effect on adenosine deaminase activity (ADA) in rats. The rats were pretreated with 50 mg/kg of GSE, i.p., prior to MTX administration (10 mg/kg, i.p.) with a second dose given 4 h and a third dose 16 h after MTX administration. Biochemical parameters were investigated 48 h after the last MTX administration. The administration of MTX increased thiobarbituric acid reactive species (TBARS) levels in hippocampus, kidney and liver, whereas induced a significant decreased in the ADA activity in the cerebral cortex, kidney and liver tissues. MTX administration significantly increased the activity of ALT(alanine aminotransferase) and urea levels and decreased uric acid levels in the serum. Urinary uric acid levels decreased in the MTX group when compared to those of the control group. The GSE along with MTX-administration significantly reversed these parameters toward to near normal. These results indicated that GSE could reduce hepatic and nephritic damage induced by MTX-treatment in young rats therefore having free radical scavenging.

Syzygium cumini inhibits adenosine deaminase activity and reduces glucose levels in hyperglycemic patients.

Syzigium cumini (L.) Skeels from the Myrtaceae family is among the most common medicinal plants used to treat diabetes in Brazil. Leaves, fruits, and barks of S. cumini have been used for their hypoglycemic activity. Adenosine deaminase (ADA) is an important enzyme that plays a relevant role in purine and DNA metabolism, immune responses, and peptidase activity. ADA is suggested to be an important enzyme for modulating the bioactivity of insulin, but its clinical significance in diabetes mellitus (DM) has not yet been proven. In this study, we examined the effect of aqueous leaf extracts of S. cumini (L.) (ASC) on ADA activity of hyperglycemic subjects and the activity of total ADA, and its isoenzymes in serum and erythrocytes. The present study indicates that: (i) the ADA activity in hyperglycemic serum was higher than normoglycemic serum and ADA activity was higher when the blood glucose level was more elevated; (ii) ASC (60-1000 microg/mL) in vitro caused a concentration-dependent inhibition of total ADA activity and a decrease in the blood glucose level in serum; (iii) ADA1 and 2 were reduced both in erythrocytes and in hyperglycemic serum. These results suggest that the decrease of ADA activity provoked by ASC may contribute to control adenosine levels and the antioxidant defense system of red cells and could be related to the complex ADA/DPP-IV-CD26 and the properties of dipeptidyl peptidase IV (DPP-IV) inhibitors which serve as important regulators of blood glucose.

Adenosine deaminase activity, lipid peroxidation and astrocyte responses in the cerebral cortex of rats after neonatal hypoxia ischemia.

Hypoxia ischemia (HI) is a common cause of damage in the fetal and neonatal brain. Lifelong disabilities such as cerebral palsy, epilepsy, behavioral and learning disorders are some of the consequences of brain injury acquired in the perinatal periods. Inflammation and formation of free radicals appear to play key roles in neonatal HI. The aim of this study was to describe the chronological sequence of adenosine deaminase (ADA) activity, the oxidative damage changes and astrocyte response using the classic model of neonatal HI. We observed an increase in the activity of ADA and lipid peroxidation in the cerebral cortex 8 days after neonatal HI. This was accompanied by a GFAP-positive, and the degree of brain damage was determined histochemically by hematoxylin-eosin (HE). Taking into account the important anti-inflammatory role of adenosine, ADA may provide an efficient means for scavenging cell-surrounding adenosine and play an important part in subsequent events of neonatal HI in association with GFAP reactive gliosis. The present investigation showed that neonatal HI causes the increase of free radicals and significant damage in the cerebral cortex. The increase in ADA activity may reflect the activation of the immune system caused by HI because the morphological analysis exhibited a lymphocytic infiltration.

Activity of ectonucleotidases and adenosine deaminase in rats exposed to cigarette smoke.

Cigarette smoke is a complex mixture of various toxic substances that are capable of initiating oxidative damage and promoting blood platelet alterations. In this study, we investigated the activities of the ectoenzymes NTPDase (ectonucleoside triphosphate diphosphohydrolase, CD39) and 5'-nucleotidase (CD73) in platelets as well as adenosine deaminase (ADA) in the plasma of rats exposed to aged and diluted sidestream smoke during 4 weeks. The rats were divided into two groups: I (control) and II (exposed to smoke). After the exposure period, blood was collected and the platelets and plasma were separated for enzymatic assay. The results demonstrated that NTPDase (with ATP as substrate) and 5'-nucleotidase (AMP as substrate) activities were significantly higher in group II (p < 0.05) as compared to group I, while no significant difference was observed for NTPDase with ADP as substrate. The ADA activity was significantly reduced in group II (p < 0.05) as compared with group I. Platelet aggregation was significantly increased in group II (p < 0.05) as compared with group I. We suggest that these alterations in the activity of enzymes from the purinergic system are associated with an increase in platelet aggregation. However, our study has demonstrated that the organism tries to compensate for this enhanced aggregation by increasing hydrolysis of AMP and reducing hydrolysis of adenosine, a potent inhibitor of aggregation and an important modulator of vascular tone.