Placental abnormalities associated with Leptospira interrogans infection in naturally infected mares.

The reproductive features of equine leptospirosis are often neglected. Equine genital leptospirosis is characterized as a silent chronic syndrome, and besides abortions, leads to placental abnormalities, stillbirths, and birth of weak foals. This study aimed to study the occurrence of placental abnormalities associated with Leptospira interrogans infection in naturally infected mares under field conditions. The studied herd had a high occurrence of placentitis and abortions. Ten pregnant mares, eight with placental abnormalities on ultrasonography and were selected. Serum and cervicovaginal mucus (CVM) samples were collected for serology and PCR, respectively. Positive samples in lipL32-PCR were submitted to the sequencing of the secY gene. In lipL32-PCR of CVM, five out of 10 (50%) mares were positive and all were characterized as Leptospira interrogans. Our results highlight the presence of placental abnormalities in the reproductive subclinical leptospirosis syndrome. We encourage field veterinarians to include leptospirosis testing in their reproductive management.

Using pregnancy associated glycoproteins (PAG) for pregnancy detection at day 24 of gestation in beef cattle.

The objective of this experiment was to determine if circulating concentrations of pregnancy associated glycoproteins (PAG) on day 24 of gestation can be utilized to diagnose pregnancy and embryo viability in beef cattle. Postpartum beef cows (n = 677) and heifers (n = 127) were exposed to a 7-day CO-Synch + CIDR estrus synchronization protocol followed by fixed-time AI (FTAI) on day 0. Blood samples were collected at day 24 after TAI to assess circulating concentrations of PAG utilizing an in-house ELISA. Pregnancy diagnosis was performed 30 and 100 days after FTAI via transrectal ultrasonography. Mean circulating PAG concentration at day 24 differed (P < 0.001) between animals diagnosed pregnant and non-pregnant at day 30 (1.69 ±â€¯0.10 ng/mL vs 0.30 ng/mL ±â€¯0.07 ng/mL; mean ±â€¯SEM; respectively). Pregnant heifers had increased PAG concentration at day 24 compared with pregnant cows (P < 0.01; 3.29 ±â€¯0.36 ng/mL vs 1.39 ±â€¯0.10 ng/mL, respectively). Based on receiver operating characteristic (ROC) curve analysis, serum concentration of PAG at day 24 ≥ 0.33 ng/mL in cows and ≥0.54 ng/mL in heifers was 95% accurate at determining pregnancy status at day 30. Heifers that experienced late embryonic mortality between day 30 and 100 of gestation had decreased circulating concentrations of PAG on day 24 (2.02 ng/mL ±â€¯0.73) compared with heifers that maintained an embryo until day 100 (3.69 ng/mL ±â€¯0.39; P = 0.02). However, there was no difference in day 24 PAG concentration (P = 0.39) between cows that maintained or lost a pregnancy (1.31 ng/mL ±â€¯0.25 vs 0.92 ng/ml ±â€¯0.50). In summary, circulating PAG concentration on day 24 of gestation may be a useful marker for early pregnancy detection in beef cattle, and might be a potential marker for predicting embryonic loss.

Teratogenicity of Mimosa tenuiflora seeds to pregnant rats.

Bone and other malformations caused by the ingestion of Mimosa tenuiflora are common in ruminants in the Brazilian semiarid. The aim of this research was to study the teratogenic effects of M. tenuiflora in Wistar rats (Rattus novergicus). The experimental group had 15 females and was fed, from the 6th to the 21st day of pregnancy, with a ration containing 10% of M. tenuiflora seeds. The control group, with 10 females, was fed with the same ration without seeds. There were no differences in weight gains, and food and water consumption between treated and control rats. Ninety bone malformations were observed in 40 of the 101 fetuses born in the experimental group, and four malformations were observed in three of the 58 fetuses born in the control group (p<0.05). The weight and number of ossification centers of the fetuses from the experimental group were higher than those from the control group (p<0.05). It is concluded that the seeds of M. tenuiflora are teratogenic to rat fetuses.

Comet assay to determine DNA damage induced by food deprivation in rats.

The aim of this work was to evaluate, by comet assay, the possible inducing of DNA lesions in peripheral blood mononuclear cells of rats subjected to acute or chronic food deprivation. Wistar male rats were subjected to 72 h of partial (50%), or total acute food deprivation, and then allowed to recover for different time periods (24, 48 and 72 h). In other experiments, comet scores were determined in peripheral blood mononuclear cells of rats subjected to chronic food deprivation (25% and 50%) for 50 days. Blood aliquots were obtained before, during and after food deprivation. Comet assay was carried out, the comet units photographed and scored (class 0 up to 3). Acute and chronic food-deprived rats presented peripheral blood mononuclear cells with DNA lesions (comet classes 1, 2 and 3) and a significant increase (p<0.05) in the number of comet units compared with its basal level. The increase was proportional to acute food deprivation time, but after being taken off, it progressively returned to basal level after 48 h (partial group) or 72 h (total group). Chronic food-deprived rats presented a progressive increase of comet score up to 5 days, and a decrease thereafter to reach a basal level. Possible mechanisms of DNA lesions are discussed.

Analysis of genotoxic potentiality of stevioside by comet assay.

Stevioside is a natural non-caloric sweetener extracted from Stevia rebaudiana (Bertoni) leaves. It has been widely used in many countries, including Japan, Korea, China, Brazil and Paraguay, either as a substitute for sucrose in beverages and foods or as a household sweetener. The aim of this work was to study its genotoxic potentiality in eukaryotic cells. Wistar rats were treated with stevioside solution (4mg/mL) through oral administration (ad libitum) and the DNA-induced damage was evaluated using the single cell gel electrophoresis (comet assay). The results showed that treatment with stevioside generates lesions in peripheral blood, liver, brain and spleen cells in different levels, the largest effect being in liver. Therefore, these undesired effects must be better understood, once the data present here point to possible stevioside mutagenic properties.

Using estrus detection patches to optimally time insemination improved pregnancy risk in suckled beef cows enrolled in a fixed-time artificial insemination program.

A multilocation study examined pregnancy risk (PR) after delaying AI in suckled beef cows from 60 to 75 h when estrus had not been detected by 60 h in response to a 7-d CO-Synch + progesterone insert (CIDR) timed AI (TAI) program (d -7: CIDR insert concurrent with an injection of GnRH; d 0: PGF injection and removal of CIDR insert; and GnRH injection at TAI [60 or 75 h after CIDR removal]). A total of 1,611 suckled beef cows at 15 locations in 9 states (CO, IL, KS, MN, MS, MT, ND, SD, and VA) were enrolled. Before applying the fixed-time AI program, BCS was assessed, and blood samples were collected. Estrus was defined to have occurred when an estrus detection patch was >50% colored (activated). Pregnancy was determined 35 d after AI via transrectal ultrasound. Cows ( = 746) detected in estrus by 60 h (46.3%) after CIDR removal were inseminated and treated with GnRH at AI (Control). Remaining nonestrous cows were allocated within location to 3 treatments on the basis of parity and days postpartum: 1) GnRH injection and AI at 60 h (early-early = EE; = 292), 2) GnRH injection at 60 h and AI at 75 h (early-delayed = ED; = 282), or 3) GnRH injection and AI at 75 h (delayed-delayed = DD; = 291). Control cows had a greater ( < 0.01) PR (64.2%) than other treatments (EE = 41.7%, ED = 52.8%, DD = 50.0%). Use of estrus detection patches to delay AI in cows not in estrus by 60 h after CIDR insert removal (ED and DD treatments) increased ( < 0.05) PR to TAI when compared with cows in the EE treatment. More ( < 0.001) cows that showed estrus by 60 h conceived to AI at 60 h than those not showing estrus (64.2% vs. 48.1%). Approximately half (49.2%) of the cows not in estrus by 60 h had activated patches by 75 h, resulting in a greater ( < 0.05) PR than their nonestrous herd mates in the EE (46.1% vs. 34.5%), ED (64.2% vs. 39.2%), and DD (64.8% vs. 31.5%) treatments, respectively. Overall, cows showing estrus by 75 h (72.7%) had greater ( < 0.001) PR to AI (61.3% vs. 37.9%) than cows not showing estrus. Use of estrus detection patches to allow for a delayed AI in cows not in estrus by 60 h after removal of the CIDR insert improved PR to TAI by optimizing the timing of the AI in those cows.

Adaptive response to H(2)O(2) protects against SnCl(2) damage: the OxyR system involvement.

The stannous ion, mainly the stannous chloride (SnCl(2)) salt form, is widely used as a reducing agent to label radiotracers with technetium-99m ((99m)Tc). These radiotracers can be employed as radiopharmaceuticals in nuclear medicine procedures. In this case, there is no doubt about absorption of this complex, because it is intravenously administered in humans, although biological effects of these agents have not been fully understood. In this work we used a bacterial system to study the cytotoxic potential of stannous chloride. It is known that SnCl(2) induces lesions that could be mediated by reactive oxygen species (ROS). We, thus, investigated the existence of cross-adaptive response between hydrogen peroxide (H(2)O(2)) and SnCl(2) and the role of the OxyR system known to promote cellular protection against oxidative damages. Here we describe the results obtained with prior treatment of different Escherichia coli strains with sub-lethal doses of H(2)O(2), followed by incubation with SnCl(2). Our data show that H(2)O(2) is capable of inducing cross-adaptive response against the lethality promoted by SnCl(2), suggesting the OxyR system participation through catalase, alkyl hydroperoxide reductase and superoxide dismutase enzymes

Biological effects of stannous chloride, a substance that can produce stimulation or depression of the central nervous system.

It was demonstrated that tin, as stannous chloride (SnCl(2)), can facilitate the neuromuscular transmission by accelerating the transmitter release from the nerve terminals in the mouse. When this salt is injected into laboratory animals, it can produce stimulation or depression of the central nervous system. Because calcium (Ca(2+)) influx into the cytoplasm is indispensable to release the transmitter, it would be possible that SnCl(2) increases the Ca(2+) influx at the nerve terminals but not by blocking the K(+) channels. SnCl(2) is known to inhibit the immune response in rodents and to induce tumor generation in thyroid gland. There is no general agreement regarding its genotoxicity and it was discussed that the effects of this salt might depend on the physicochemical conditions and the route of its administration. SnCl(2) has been used in many sectors of human interest, such as food industry and nuclear medicine. This salt is directly administered to human beings endovenously, when it is used as a reducing agent to prepare 99mTc-radiopharmaceuticals which are also used for cerebral studies. SnCl(2) is capable to promote the generation of reactive oxygen species (ROS) that are responsible for the oxidative stress. Oxidative stress has been related with aging and other neurological diseases. So, it is relevant to evaluate other biological effects of SnCl(2). We decided to study these effects using Escherichia coli mutant strains, deficient in DNA repair genes, and supercoiled plasmid DNA. We evaluated the influence of medicinal plants, metal chelating agents, and ROS scavengers against the SnCl(2) deleterious effects. Our results show that SnCl(2) produced lesions in vitro as well as in vivo. This inactivation may be due to the production of ROS. We observed that the genotoxic effect of SnCl(2) was partly inhibited or disappeared, when the treatments were done in the presence of medicinal plants, metal chelating agents, and ROS scavengers. In conclusion, these findings suggest that the SnCl(2) biological effects may be associated with the generation of ROS. Moreover, we can speculate that ROS could be associated with the detrimental effects in the brain due to exogenous or endogenous metals.

Bilateral arteriovenous malformations: case report.

The authors describe a case of supratentorial bilateral arteriovenous malformations in a patient who suffered an intracerebral hemorrhage. It was radiologically demonstrated that the arteriovenous malformations were separate and bilateral, located in the temporal lobes. They were removed in two operations with preoperative embolization of one. The patient did well with no neurological damage.

Ocular health myths among a hospital staff.

In order to evaluate their common beliefs in the field of ocular health, an exploratory survey was carried out among 122 professionals belonging to different ranks and specialty areas of the University of Campinas Clinical Hospital (UNICAMP-CH), São Paulo, Brazil. The non-structured questionnaire used asked about common ophthalmologic problems as well as the presence of popular myths about ocular health, such as: 'cure' of visual problems by the use of glasses; reading under insufficient lighting or watching TV too much close to the apparatus is harmful; consequences from the intensive use of the eyes; or special food being needed for better vision. The results indicated the existence of various misconceptions, even among health professionals, such as: belief in the cure of refractive problems by the use of glasses (40.0%); or damage to vision due to insufficient lighting, watching TV too much close to the apparatus or from the intensive use of the eyes (86.7%). Among the professionals performing activities within the ophthalmology department, 62.5% admitted believing in visual damage as a result of conditions such as those mentioned above and 37.5% stated that reading in a moving vehicle is detrimental to vision. From these data, one is entitled to conclude that misconceptions continue to be present, even among professionals in the health area; this indicates that educational programs in ocular health should be provided, especially for individuals working within a hospital ophthalmological service.

Stannous chloride mediates single strand breaks in plasmid DNA through reactive oxygen species formation.

Stannous ion (Sn) has been employed in nuclear medicine and in food industry. We described that Stannous Chloride (SnCl2) inactivation effect in Escherichia coli is mediated by a Fenton-like reaction. The effect of SnCl2 was studied through: (i) the alteration of plasmid topology in neutral and acidic pH by gel electrophoresis; and (ii) the transformation efficiency of an wild type E. coli strain. Treatment of plasmid DNA pUC 9.1 with SnCl2, at pH 7.4, results in DNA single-strand breaks (SSB), in a dose-dependent manner. Addition of sodium benzoate partly inhibited the DNA damage, while EDTA completely abolishes DNA-SSB. Furthermore, the ability of the plasmid to transform E. coli was reduced. At pH 1.3, SnCl2 exerts a protective effect on plasmid against HCI depurination. Our results suggest the generation of ROS, such as *OH by a Fenton-like reaction, close to the site of the lesions due to a possible complexation of stannous ion to DNA.

Damage induced by stannous chloride in plasmid DNA.

Stannous chloride (SnCl(2)) is widely used in daily human life, for example, to conserve soft drinks, in food manufacturing and biocidal preparations. In nuclear medicine, stannous chloride is used as a reducing agent of Technetium-99m, a radionuclide used to label different cells and molecules. In spite of this, stannous chloride is able to generate reactive oxygen species (ROS) which can damage DNA. In this work, plasmid DNA (pUC 9.1) was incubated with SnCl(2) under different conditions and the results analyzed through DNA migration in agarose gel electrophoresis. Our data reinforce the powerful damaging effect induced by stannous ion and suggest that this salt can play a direct role in inducing DNA lesions.

Genotoxic potentiality of aqueous extract prepared from Chrysobalanus icaco L. leaves.

Plants have been related to our lives, being used as medicine, regardless of scientific evidence of side effects. This work analyses the toxicological effects of Chrysobalanus icaco L. aqueous extract, used in different pathologies. It was studied through: (i) alteration of plasmid pUC 9.1 topology; (ii) survival of bacterial strains submitted, or not, to previous treatment with SnCl2; (iii) transformation efficiency of E. coli strain by the treatment with the plasmid pUC 9.1. In (i), the treatment of the plasmid resulted in DNA single-strand breaks (SSB). A decrease of the lethal effect induced by SnCl2 in presence of the extract was found, while no C. icaco bacterial survival reduction was observed. The transformation efficiency of the plasmid was also reduced. Results suggest that the extract could present a potential genotoxic effect, as demonstrated either by the induction of SSB in plasmid or in transformation efficiency experiments. Finally, it presents an antioxidant action.

Mutational potentiality of stannous chloride: an important reducing agent in the Tc-99m-radiopharmaceuticals.

Stannous chloride (SnCl2) is frequently used in nuclear medicine as a reducing agent to label many radiopharmaceutical products with technetium-99m (99mTc). The aim of the present paper was to study the role of DNA repair genes in the repair of SnCl2-induced damage, using mutant strains of Escherichia coli lacking one or more DNA repair genes. Our results suggest that the product of the xthA gene, exonuclease III, is required for the repair of lesions induced by SnCl2. We further investigated the mutagenic properties of SnCl2 to a molecular level by using the supF tRNA gene as target in a forward mutational system. We have found that the survival of E. coli cells was strongly reduced with increasing concentrations of SnCl2. Moreover, when the shuttle vector pAC189 carrying the supF gene was treated with SnCl2, and then transfected to E. coli, we observed that its transformation efficiency dropped when compared to the non-treated control, with a parallel increase in mutation frequency after the damaged plasmids have replicated in bacterial cells. The mutation spectrum induced by SnCl2 reveals a high frequency of base substitutions, involving guanines. Sequence analysis of 41 independent supF mutant plasmids revealed that 39 mutants contained base substitutions, with 21 G:C to T:A and 17 G:C to C:G transversions. G to T transversions presumably resulted from 8-oxoG. However, the G to C one may be due to a yet unidentified lesion.

Lethality induced by stannous chloride on Escherichia coli AB1157: participation of reactive oxygen species.

Stannous chloride (SnCl2) has been widely used in nuclear medicine as a reducing agent of pharmaceutical products radiolabelled with technetium-99m. To verify whether the lethality induced by this salt could be mediated by reactive oxygen species (ROS), Escherichia coli cultures were treated with SnCl2 in the presence of catalase, ROS scavengers or metal-ion chelators. The inactivation effect, as measured by survival determination, was abolished by thiourea, sodium benzoate, dipyridyl or catalase. The results suggest the participation of ROS, generated by a Fenton-like reaction, in the lethal effect induced by SnCl2.

Genotoxic effects of stannous chloride (SnCl2) in K562 cell line.

The toxic effects of SnCl2 in K562 cells were analyzed in this study. This cell line is resistant to reactive oxygen species (ROS) making it suitable to evaluate the impact of SnCl2 in culture either through ROS or by direct toxicity using Trypan blue dye exclusion, comet and flow cytometry assays. An important loss of viability induced by SnCl2 in a dose-response manner was observed in cells treated in Tris-buffered saline (TBS). This necrotic cell death was further confirmed by flow cytometry. On the other hand, there was no loss of viability when cells were treated in rich medium (RPMI). DNA damage was visualized in SnCl2-treated K562 cells in both tested conditions. The data indicate that SnCl2 induces DNA damage and reduces K562 viability. Both actions seem to be correlated with ROS formation and direct linkage to DNA.

Distal anterior cerebral artery aneurysms.

BACKGROUND: The incidence of saccular aneurysms in the distal anterior cerebral artery (DACA aneurysms), also called pericallosal or A2 aneurysms, has been estimated to be from 1.5 to 9.0% of all intracranial aneurysms in large series in the literature [5,10,12,18]. All reported series of DACA aneurysms have shown a high association with intracranial aneurysms in other locations. These aneurysms are fragile, frequently rupture prematurely during exposure, and have a higher morbidity than expected from their angiographic appearance and location. METHODS: A total of 1,350 patients with cerebral aneurysms were operated in the Department of Neurosurgery at Santa Casa Hospital in Belo Horizonte from January 1982 to January 1998. Seventy-two of those 1,350 patients had DACA aneurysms (5.3%), 51 female and 21 male. The age ranged from 26 to 69 years, the mean age being 44 years. This group of patients is reported herein. We propose three different approaches to DACA aneurysms depending on their location, all of them performed through a unilateral triangular bone flap that can then vary from fronto-basal to parietal. RESULTS: There was no mortality among patients with a single DACA aneurysm. Five deaths in this series were cases of multiple aneurysms. In patients with preoperative Hunt and Kosnick grades I and II [9], we had 90% good results. In grade III patients, we achieved 68.4% good results. The only grade IV patient had a full recovery. All 74 DACA aneurysms in the 72 operated patients were completely clipped, including two giant aneurysms. CONCLUSION: DACA aneurysms have higher morbidity and mortality rates when compared to other supratentorial aneurysms. We recommend the use of a unilateral interhemispheric approach as the most appropriate for aneurysms in this location. In cases of patients with multiple aneurysms who require two different craniotomies, we propose two surgical stages, starting with the aneurysm that has bled. A high mortality rate was noted when two craniotomies were performed in the same sitting.

Giant posterior cerebral artery aneurysm in a 4-year-old child: case report.

Posterior cerebral artery aneurysms in children aged 5 years or less are very rare. We were able to find only 10 cases previously described in the literature. We present a case of giant bilobulated aneurysm of the distal right posterior cerebral artery in a 4-year-old child with an initial history of spontaneous subarachnoid hemorrhage. The aneurysm was clipped and the patient had full recovery. Based on the literature review, we discuss the characteristics of these rare aneurysms, making a comparison with different age groups.

Congenital inclusion cysts of the anterior fontanelle.

BACKGROUND: Congenital inclusion cysts of the anterior fontanelle are rare lesions. Both dermoid and epidermoid cysts are located in the midline of the scalp and occupy the subgaleal space. METHODS: We report 7 cases, 4 boys (57.1%), and 3 girls (42.9%), with ages ranging from 3 months to 16 years (mean 40.85 +/- 68.56 months; median 10 months). Four patients (57.1%) were white and 3 (42.9%) were Afro-Brazilian. RESULTS: The cysts had manifested soon after birth in all patients. They gradually enlarged, with no intracranial extensions. Four patients had dermoid cysts and the others had epidermoid cysts. All of them underwent surgery with complete excision of the cyst and no capsular rupture. There were no complications and no deaths. CONCLUSIONS: Congenital inclusion cysts of the anterior fontanelle are rare lesions that usually manifest at birth. The diagnosis is usually easy and surgery is mandatory, with a good prognosis. Recurrence is rare.

Boldine action against the stannous chloride effect.

Peumus boldus extract has been used in popular medicine in the treatment of biliar litiase, hepatic insufficiency and liver congestion. Its effects are associated to the substance boldine that is present in its extract. In the present work, we evaluated the influence of boldine both in: (i) the structural conformation of a plasmid pUC 9.1 through gel electrophoresis analysis; and in (ii) the survival of the strain of Escherichia coli AB1157 submitted to reactive oxygen species (ROS), generated by a Fenton like reaction, induced by stannous chloride. Our results show a reduction of the lethal effect induced by stannous chloride on the survival of the E. coli culture in the presence of boldine. The supercoiled form of the plasmid is not modified by stannous chloride in the presence of boldine. We suggest that the protection induced by boldine could be explained by its anti-oxidant mechanism. In this way, the boldine could be reacting with stannous ions, protecting them against the oxidation and, consequently, avoiding the generation of ROS.