Analysis of the prevalence of polymorphisms in the glutathione S transferase gene (GST) in cataract patients from Goiânia.

The aim of this study was to determine the prevalence of polymorphisms in the glutathione S-transferase genes GSTM1 and GSTT1 in patients with lens opacity (cataract). Peripheral blood samples were obtained from male and female patients (N = 23) with cataract. The GSTM1 and GSTT1 polymorphic regions were amplified by polymerase chain reaction, and the amplification products were electrophoresed on a 2% agarose gel. The obtained bands were by staining with ethidium bromide. The results were compared by a chi-square test using the BioEstat software (v.5.0). The frequencies of the GSTM1- and GSTT1-null genotypes were higher than those of the GSTM1- and GSTT1-present genotypes. The frequency of GSTT1-null genotypes was approximately 1.7 times higher than that of GSTM1, which was a statistically significant difference (P = 0.0019). Although a consensus remains to be reached on the correlation between genetic polymorphisms in GSTs and cataract susceptibility, the observations from most scientific studies are similar to those reported in this study. Thus, we conclude that the absence of these genes, particularly GSTT1, is correlated with the development of lens opacity.

Analysis of the GSTM1-null polymorphism in patients with pterygium from Goiânia, Goiás Brazil.

The first reports about pterygium date back to Hippocrates, and this disease still threatens vision health around the world. Pterygium is a formation of fibrous tissue consisting of highly vascularized epithelial and subepithelial tissue that grows excessively and with an abnormal shape on the cornea. Many physical and biological factors are associated with the pathogenesis of pterygium, including heat, dust, and other particles in the atmosphere, and immunological mechanisms, mechanisms involving extracellular matrix reorganization, growth factors, cytokines, apoptosis, and angiogenesis. The aim of this study was to further investigate the association between polymorphisms in GSTM1 and the formation of pterygium. We collected peripheral blood samples from 90 patients diagnosed with pterygium and from 23 subjects with-out the disease in order to perform molecular analysis of the GSTM1 gene. Subjects with one or two copies of the GSTM1 allele had a normal genotype while those without any copies of the allele had a null geno-type. The chi-square test or the Fisher exact test was performed in order to investigate possible associations between the molecular analysis and the risk of pterygium. A significant difference between the frequency of the GSTM1-null genotype in patient and control groups was identified. However, sub-group analysis found that the GSTM1-null genotype was statistically significant in men, but not in women, and in Caucasians, but not in Brown or Black groups. Furthermore, the GSTM1-null geno-type was not related to any of the risk factors analyzed: cases in family, occupational exposure, smoking, hypertension, and diabetes.

Pterygium in patients from Goiânia, Goiás, Brazil.

Pterygium is an inflammatory and degenerative ocular surface disease in which the conjunctiva on the cornea grows to form a fibrous tissue in the shape of a triangle. The disorder may be characterized by cell proliferation, inflammatory processes, fibrosis, angiogenesis, and destruction of the extracellular matrix. The anomaly is considered a degenerative eye disease and is erroneously confused with cataract. It displays similar features to those of tumors, such as local invasion, metaplasia of epithelial cells, presence of oncogenic viruses (human papilloma virus), inactivation of tumor suppressor genes (e.g., p53), and loss of heterozygosity. The treatment of pterygium is based on factors such as the evolution and progression of the disease, risk factors, symptoms, and patient age. Considerations about the best technique for the surgical removal of pterygium remain controversial, and complications and recurrence are very common. The development of new surgical techniques and adjuvant drugs is thus necessary. This study aims to analyze and compare the frequency of the GSTT1 genotypes in relation to pterygium through statistical analyzes in order to build a genotypic profile for the Replicon patients. The genotypic profile of the GSTT1-null polymorphism in Goiânia showed no significant difference when the frequency of the null genotype was compared between the control and experimental groups. The null genotype was more frequent in the population studied. Furthermore, the GSTT1 genotype was not related to the analyzed risk factors for pterygium, namely gender, ethnicity, family history, occupational exposure, smoking, hypertension, and diabetes.

Amitriptyline converts non-responders into responders to low-frequency electroacupuncture-induced analgesia in rats.

AIMS: The purpose of this study was to examine whether the use of intraperitoneal or intrathecal amitriptyline combined with electroacupuncture modifies the tail-flick reflex and incision pain in rats that normally do not have analgesia to electroacupuncture in the tail-flick test (non-responder rats). MAIN METHODS: Changes in the nociceptive threshold of intraperitoneal or intrathecal saline- or amitriptyline-treated non-responder rats were evaluated using the tail-flick or incision pain tests before, during and after a 20-min period of electroacupuncture, applied at 2 Hz to the Zusanli and Sanynjiao acupoints. Amitriptyline was used at doses of 0.8 mg/kg or 30 µg/kg by intraperitoneal or intrathecal route, respectively. At these doses, amitriptyline has no effect against thermal or incision pain in rats. KEY FINDINGS: Rats selected as non-responders to the analgesic effect of electroacupuncture 2 Hz in tail-flick and incision pain tests become responders after an intraperitoneal or intrathecal injection of amitriptyline. SIGNIFICANCE: Amitriptyline converts non-responder rats to rats that respond to electroacupuncture with analgesia in a model of thermal phasic pain and anti-hyperalgesia in a model of incision pain.

Amitriptyline prolongs the antihyperalgesic effect of 2- or 100-Hz electro-acupuncture in a rat model of post-incision pain.

The mechanisms through which electro-acupuncture (EA) and tricyclic antidepressants produce analgesia seem to be complementary: EA inhibits the transmission of noxious messages by activating supraspinal serotonergic and noradrenergic neurons that project to the spinal cord, whereas tricyclic antidepressants affect pain transmission by inhibiting the reuptake of norepinephrine and serotonin at the spinal level. This study utilized the tail-flick test and a model of post-incision pain to compare the antihyperalgesic effects of EA at frequencies of 2 or 100 Hz in rats treated with intraperitoneal or intrathecal amitriptyline (a tricyclic antidepressant). A gradual increase in the tail-flick latency (TFL) occurred during a 20-min period of EA. A strong and long-lasting reduction in post-incision hyperalgesia was observed after stimulation; the effect after 2 Hz lasting longer than after 100-Hz EA. Intraperitoneal or intrathecal amitriptyline potentiated the increase in TFL in the early moments of 2- or 100-Hz EA, and the intensity of the antihyperalgesic effect of 100-Hz EA in both the incised and non-incised paw. In contrast, it did not significantly change the intensity of the antihyperalgesic effect of 2-Hz EA. The EA-induced antihyperalgesic effects lasted longer after intraperitoneal or intrathecal amitriptyline than after saline, with this effect of amitriptyline being more evident after 100- than after 2-Hz EA. The synergetic effect of amitriptyline and EA against post-incision pain shown here may therefore represent an alternative for prolonging the efficacy of EA in the management of post-surgical clinical pain.

Baclofen, an agonist at peripheral GABAB receptors, induces antinociception via activation of TEA-sensitive potassium channels.

BACKGROUND AND PURPOSE: Central anti-nociceptive actions of baclofen involve activation of K+ channels. Here we assessed what types of K+ channel might participate in the peripheral anti-nociception induced by baclofen. EXPERIMENTAL APPROACH: Nociceptive thresholds to mechanical stimulation in rat paws treated with intraplantar prostaglandin E2.(PGE2) to induce hyperalgesia were measured 3 h after PGE2 injection. Other agents were also given by intraplantar injection. KEY RESULTS: Baclofen elicited a dose-dependent (15 - 240 microg per paw) anti-nociceptive effect. An intermediate dose of baclofen (60 microg) did not produce antinociception in the contralateral paw, showing its peripheral site of action. The GABAB receptor antagonist saclofen (12.5 - 100 microg per paw) antagonized, in a dose-dependent manner, peripheral antinociception induced by baclofen (60 microg), suggesting a specific effect. This antinociceptive action of baclofen was unaffected by bicuculline, GABAA receptor antagonist (80 microg per paw), or by (1,2,5,6 tetrahydropyridin-4-yl) methylphosphinic acid, GABAC receptor antagonist (20 microg per paw). The peripheral antinociception induced by baclofen (60 microg) was reversed, in a dose-dependent manner, by the voltage-dependent K+ channel blockers tetraethylammonium (7.5 - 30 microg per paw) and 4-aminopyridine (2.5 - 10 microg per paw). The blockers of other K+ channels, glibenclamide (160 microg), tolbutamide (320 microg), charybdotoxin (2 microg), dequalinium (50 microg) and caesium (500 microg) had no effect. CONCLUSIONS AND IMPLICATIONS: This study provides evidence that the peripheral antinociceptive effect of the GABAB receptor agonist baclofen results from the activation of tetraethylammonium-sensitive K+ channels. Other K+ channels appear not to be involved.

Atividade analgésica e antiedematogênica de Polygala paniculata L. (Polygalaceae) selvagem e obtida por micropropagação / Analgesic and antiedematogenic activities of wild and micropropagated Polygala paniculata L (Polygalaceae)

Polygala paniculata L. (Polygalaceae) é uma erva que ocorre em todas as regiões do Brasil. No presente trabalho, foram avaliadas as atividades analgésica, através do teste da placa quente, da retirada de cauda e da formalina, e antiedematogênica, através do teste do edema de orelha induzido por óleo de cróton, dos extratos etanólicos obtidos das partes aéreas de Polygala paniculata selvagem e cultivadas por micropropagação. A aplicação oral do extrato etanólico de Polygala paniculata apresentou atividade analgésica, em ratos, tanto em testes de dor induzida por agentes térmicos (testes da placa quente e de retirada da cauda) quanto por agentes químicos (teste da formalina), de modo que os melhores resultados foram obtidos na dose de 400 mg/kg. Também foi observada redução na formação de edema de orelha induzida pela aplicação de óleo de cróton. Os efeitos provocados pelos extratos obtidos a partir das plantas cultivadas in vitro foram menos pronunciados que aqueles produzidos pelos extratos das plantas selvagens, embora ambos tenham sido significativos. Estes resultados sugerem que o extrato etanólico de Polygala paniculata possui atividades analgésica e antiedematogênica.

The ethanolic extracts of Polygala paniculata L. (Polygalaceae), wich is a herbaceous plant widely distributed all over Brazil, were tested for their analgesic effects using hot plate, tail flick and formalin test models, and for their antiedematogenic effects using croton oil induced ear oedema. The ethanolic extracts obtained from wild and micropropagated plants produced analgesic effects against thermal and chemical induced pain. The highest results were observed at the dose of 400 mg/kg. The inhibition of ear oedema in mice was also observed after treatment with ethanolic extract of Polygala paniculata. The effects produced by micropropagated plants were lower than wild plants, whereas both had produced significant effects. These results suggest that the ethanolic extracts from wild and micropropagated Polygala paniculata possess analgesic and antiedematogenic effects.

Do endogenous opioids and nitric oxide participate in the anticonvulsant action of dipyrone?

It was previously reported that systemic administration of dipyrone inhibited the tonic component of generalized tonic-clonic seizures in both the electroshock and the audiogenic seizure models. The aim of the present study was to investigate the mechanisms involved in the anticonvulsant action of dipyrone by assessing the role of nitric oxide and opioids in the electroshock (female 60- to 90-day-old Wistar rats, N = 5-11) and audiogenic seizure (female 60- to 90-day-old Wistar audiogenic rats, N = 5-11) models of epilepsy. Naloxone (5 mg/kg, sc) significantly reversed the anticonvulsant effect of dipyrone in rats submitted to the induction of audiogenic seizures (ANOVA/Bonferroni's test), suggesting the involvement of opioid peptides in this action. In the electroshock model no reversal of the anticonvulsant effect of dipyrone by naloxone (5 mg/kg, sc) was demonstrable. The acute (120 mg/kg, ip) and chronic (25 mg/kg, ip, twice a day/4 days) administration of L-NOARG did not reverse the anticonvulsant action of dipyrone in the audiogenic seizure model, suggesting that the nitric oxide pathway does not participate in such effect. Indomethacin (10, 20 and 30 mg/kg, ip) used for comparison had no anticonvulsant effect in the audiogenic seizure model. In conclusion, opioid peptides but not nitric oxide seem to be involved in the anticonvulsant action of dipyrone in audiogenic seizures

Do endogenous opioids and nitric oxide participate in the anticonvulsant action of dipyrone?

It was previously reported that systemic administration of dipyrone inhibited the tonic component of generalized tonic-clonic seizures in both the electroshock and the audiogenic seizure models. The aim of the present study was to investigate the mechanisms involved in the anticonvulsant action of dipyrone by assessing the role of nitric oxide and opioids in the electroshock (female 60- to 90-day-old Wistar rats, N = 5-11) and audiogenic seizure (female 60- to 90-day-old Wistar audiogenic rats, N = 5-11) models of epilepsy. Naloxone (5 mg/kg, sc) significantly reversed the anticonvulsant effect of dipyrone in rats submitted to the induction of audiogenic seizures (ANOVA/Bonferroni's test), suggesting the involvement of opioid peptides in this action. In the electroshock model no reversal of the anticonvulsant effect of dipyrone by naloxone (5 mg/kg, sc) was demonstrable. The acute (120 mg/kg, ip) and chronic (25 mg/kg, ip, twice a day/4 days) administration of L-NOARG did not reverse the anticonvulsant action of dipyrone in the audiogenic seizure model, suggesting that the nitric oxide pathway does not participate in such effect. Indomethacin (10, 20 and 30 mg/kg, ip) used for comparison had no anticonvulsant effect in the audiogenic seizure model. In conclusion, opioid peptides but not nitric oxide seem to be involved in the anticonvulsant action of dipyrone in audiogenic seizures.

Magnetic resonance cholangiopancreatography in cystic lesions of the pancreas.

There are few reports about magnetic resonance cholangiopancreatography (MRCP) in cystic lesions of the pancreas (KLP). For this reason, we have undertaken a prospective study evaluating the diagnostic efficiency of MRCP as compared with ultrasonography. Twenty-four patients with KLP were examined with magnetic resonance imaging (MRI), and standard and cholangiopancreatography. There were seven cases of cysts associated with acute pancreatitis, 11 patients with KLP and chronic calcifying pancreatitis, five cases of cystic neoplasms of the pancreas, and one polycystic disease of the gland. All cases were first submitted to ultrasonography, which failed to diagnose only a case of cyst associated with chronic pancreatitis depicted by MRCP. We used a GE Signa Horizon 1.5-T system (20 examinations) and a Siemens Magneton Plus 1.5-T machine (four examinations). Eleven patients were operated on. In all cases, it was possible to identify the cysts, the main pancreatic duct and the biliary tree, and verify the relationship of the cyst with neighboring organs. Communication of the cyst with the main pancreatic duct was described in five instances, but we cannot be sure that MRCP would have depicted all cyst-duct communications. The MRI and MRCP images were confirmed by surgery in the 11 operated-on cases. The diagnosis of duct alterations and small pancreatic stones in initial cases of chronic calcifying pancreatitis may be problematic. Clinical findings are very important data to be considered in the differential diagnosis of KLP. Together with the clinical data, MRCP is a very important technique in the diagnostic and therapeutic decision making of KLP. Standard magnetic resonance is advisable as part of the examination in all cases. MRCP is not invasive, is reliable if one knows its limitations, and the patient can return at once to his activities. It allows the analysis of many variables in one examination, contributing to better therapy.

[Effect of electromagnetic fields on osteogenesis: an experimental study on rats]. / Efeito do campo magnético na osteogênese: estudo experimental em ratos.

The authors studied experimentally the electromagnetic pulsing field effects in an experimental model in rats, for evaluation of the velocity of consolidation of tibial and fibular fractures. The animals were followed for a period of three weeks under continuous stimulation and there were done radiological evaluation weekly and histological study at the end of the study. There were no histological, clinical or radiological differences between the group of rats submitted to electromagnetic pulsing fields and the control group.