Dual immune effect of iNKT cells considering human cutaneous and visceral leishmaniasis: An example of cell plasticity according to different disease scenarios.

Although the semi-invariant natural killer T cells (iNKT) are a small subpopulation of cells in the peripheral blood, they are presumed to play a role in early stages of infection against various pathogens, including protozoa. This work investigates the activation status and cytokine profile of iNKT cells during human Leishmania infantum and Leishmania braziliensis infection. We studied iNKT cells in patients with symptomatic active visceral leishmaniasis (AVL) (n = 8), patients with symptomatic active cutaneous leishmaniasis (ACL) (n = 13), negative endemic controls (NEC) (n = 6) and non-endemic controls (NonEC) (n = 6), with and without total Leishmania antigen stimulus (TLA). The number of iNKT cells in the peripheral blood of patients with ACL and AVL unaltered in relation to control groups. Moreover, the iNKT cells from ACL showed a hyperactivation profile compared to patients with AVL. Additionally, TLA induced IFN-gamma production in iNKT cells from patients with ACL, while in iNKT of patients with AVL, TLA induced a decrease in this cytokine. Higher IL-17 and IL-10 production by iNKT cells from patients with ACL were also observed compared to all other groups. There were no changes in iNKT IL-10-producing cells in AVL after TLA stimulation. However, TLA induced increase in IL-10 in iNKT cells in patients with ACL. These findings suggest that, although iNKT cells showed distinct profiles in patients with ACL and AVL, they play a dual role in immune modulation in both Leishmania infections.

Low serum levels of vitamin B12 in older adults with normal nutritional status by mini nutritional assessment.

Undernutrition as well as low levels of vitamin B12 and folic acid are common problems among older adults. However, recommended routine nutritional status assessment tools may result in inadequate vitamin serum levels to go unnoticed. Therefore, the aim of this study is to evaluate the inadequacy of serum levels of vitamin B12 and folic acid within Mini Nutritional Assessment (MNA) classification categories among older adults. A cross-sectional study was conducted with 97 older adults residing in care homes in Portugal. Undernutrition was identified through the MNA, and serum levels of vitamin B12 and folic acid were measured using chemiluminescence. Cognitive function, depressive symptoms and functional characteristics were also assessed using the Abbreviated Mental Test Score, the Epidemiologic Studies Depression Scale and the Barthel Index, respectively. The mean age of older adults was 82.2 (6.3) years; 3.1% were undernourished and 26.8% were at undernutrition risk. In the MNA normal nutritional status group, 11.8% presented vitamin B12 deficiency (<200 pg/ml), 32.4% had low serum levels (200-400 pg/ml) and 4.4% had folic acid deficiency (<3 ng/ml). A high proportion of older adults with low serum levels of vitamin B12 presenting normal nutritional status by MNA was identified. This finding emphasizes the need to evaluate serum vitamin B12 levels, independently of the MNA results.

Molecular identification of Trichogramma species from regions in Brazil using the sequencing of the ITS2 region of ribosomal DNA.

The objective of this work was the identification and differentiation of Trichogramma exiguum Pinto and Platner species, T. pretiosum Riley, and T. galloi Zucchi using sequences of the ITS2 region of ribosomal DNA. After extracting DNA from the studied species, a PCR reaction was performed, where the amplified samples were subjected to sequencing. The sequences obtained were submitted to a similarity search in GenBank (NCBI - National Center for Biotechnology Information) using the BLAST program, aiming to determine the similarity of these sequences with the species already deposited in the referenced database, and then multiple sequences were aligned using version 2.0 of the ClustalX program. According to the results of the multiple alignments of all sequences obtained, it was possible to observe the differences between the T. pretiosum, T. galloi and T. exiguum species. It was concluded that using the sequences of the ITS2 region of the ribosomal DNA was efficient in the differentiation of the studied Trichogramma species, which suggests a strong inter-specific variation among species.

Toxoplasma gondii isolates from free-range chickens from the northeast region of Brazil.

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 152 free-range chickens (Gallus domesticus) from 22 municipalities in 7 northeastern states (Pernambuco, Rio Grande do Norte, Maranhão, Bahia, Ceará, Sergipe, and Alagoas) of Brazil was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT); 81 (53.3 %) chickens had titers of 1:5 in 26, 1:10 in 9, 1:20 in 4, 1:40 in 1, 1:80 in 6, 1:160 in 6, 1:320 in 13, 1:640 in 6, 1:1,280 in 3, 1:2,560 in 6, and 1:5,120 or higher in 1. Hearts and brains of 81 seropositive chickens were bioassayed individually in mice. Toxoplasma gondii was isolated from 23 chickens with MAT titers of 1:5 or higher; the isolates were designated TgCKBr165-187. Five isolates killed all infected mice. Results indicate widespread contamination of rural environment in Brazil with T. gondii oocysts.

Septicemia caused by Vibrio cholerae O1 biotype El Tor, in São Paulo, Brazil.

We reported a case of septicemia by Vibrio cholerae O1, in São Paulo, Brazil. A 70-year-old male patient, living in an urban area, entered the emergency service having sepsis, dying 12 hours later. Blood culture was positive for Vibrio cholerae O1. This is the first case of bacteremia by Vibrio cholerae O1 reported in South America.

Septicemia caused by Vibrio cholerae O1 biotype El Tor, in São Paulo, Brazil

We reported a case of septicemia by Vibrio cholerae O1, in São Paulo, Brazil. A 70-year-old male patient, living in an urban area, entered the emergency service having sepsis, dying 12 hours later. Blood culture was positive for Vibrio cholerae O1. This is the first case of bacteremia by Vibrio cholerae O1 reported in South America.

Prediction of potential thermostable proteins in Xylella fastidiosa.

The average protein (E+K)/(Q+H) ratio in organisms has already been demonstrated to have a strong correlation with their optimal growth temperature. Employing the Thermo-Search web tool, we used this ratio as a basis to look for thermostable proteins in a mesophile, Xylella fastidiosa. Nine proteins were chosen to have their three-dimensional structures modeled by homology, using mainly proteins from mesophiles as templates. Resulting models featured a high number of hydrophobic interactions, a property that has been previously associated with thermostability. These results demonstrate the interesting possibility of using the (E+K)/(Q+H) ratio to find individual thermostable proteins in mesophilic organisms.

Effects of transdermal and oral estrogen replacement on lipids and glucose metabolism in postmenopausal women with type 2 diabetes mellitus.

OBJECTIVE: To compare the effects of oral and transdermal estrogen replacement on lipid and glucose metabolism in postmenopausal women with diabetes mellitus type 2. DESIGN AND METHODS: In an open, randomized, cross-over study, 21 diabetic postmenopausal women were treated with transdermal 17beta-estradiol 50 microg or oral conjugated equine estrogens (CEE) 0.625 mg daily, both associated with 300 mg/day of oral micronized progesterone for 12 days monthly during 6 months each. After a 12-h overnight fasting period, blood glucose, insulin, glycosylated hemoglobin (HbA1c) and lipoprotein profile were evaluated, at baseline and after 6 months of each schedule of hormone replacement therapy (HRT). Insulin sensitivity was determined by homeostasis model assessment (HOMA). RESULTS: HRT had no negative influence on glucose metabolism. After 6 months of CEE treatment, there was a significant increase in high-density lipoprotein (HDL) cholesterol, but also in triglycerides, of 9.0% and 20.7%, respectively (p = 0.04). The levels of total cholesterol and low-density lipoprotein (LDL) cholesterol were unaffected. Transdermal estradiol did not affect the lipid profile. CONCLUSIONS: Hormone replacement therapy with either oral or transdermal estrogen plus micronized progesterone has no harmful influence on glucose metabolism in type 2 diabetic postmenopausal women; whether the increase in HDL cholesterol, but also in triglyceride levels, makes oral CEE the better choice remains an open question.

Glutamate transport in rat cerebellar granule cells is impaired by inorganic epileptogenic agents.

There is evidence that extracellular glutamate levels are elevated in certain brain regions immediately prior to and during induction and propagation of seizures. There appears to be a correlation between the capacity of removing released glutamate and the genesis of epileptiform activity. Some models make use of metals, such as Co(2+) and Ni(2+), to induce epilepsy. We used patch-clamp recordings to measure the electrogenic glutamate transport in neuronal cells. The present results indicate that Co(2+) (1 mM) and Ni(2+) (5 mM) blocked glutamate transport by 17.6+/-3.9% (n=5, P<0.05) and by 31.8+/-6.2% (n=7, P<0.05), respectively. Ni(2+) inhibited glutamate uptake in a dose-dependent manner. The IC(50) value obtained was 66.6 microM and the maximum inhibition was 40%. We conclude that one mechanism that may explain the seizures induced by exposure to those divalent cations is inhibition of the glutamate transporter.

Effects of crotoxin on the action potential kinetics of frog skeletal muscle.

1. The effect of crotoxin on the action potential kinetics of frog (Rana catesbeiana; 60-80 g) skeletal muscle was studied using a modified Ringer solution containing 1.6 mM KCl. 2. Crotoxin affected the kinetics of the action potential in a dose-dependent manner (90 to 460 nM). At 230 nM, crotoxin prolonged the duration of the action potential (from 1.1 +/- 0.1 to 1.6 +/- 0.1 ms) and slowed the rates of depolarization (from 282.0 +/- 7.3 to 196.0 +/- 13.2 V/s) and repolarization (from -81.4 +/- 6.9 to -55.6 +/- 3.8 V/s), in a dose-dependent manner. Its phospholipase subunit (component B) was five times less effective. 3. No effect of crotoxin was observed in the presence of 2.5 mM KCl or when SrCl2 was substituted for CaCl2. Lowering the muscle temperature to 12 degrees C did not reduce the effect of crotoxin. 4. No effect on the passive membrane response to hyperpolarizing current pulses was observed, which implies no major effect on the membrane resistance and capacitance. 5. It is concluded that crotoxin reduces the Na+ current and slows down the repolarization mechanism. This effect is probably not dependent on the phospholipase A2 activity of crotoxin and is inhibited by the substitution of Sr2+ for Ca2+.

Effects of crotoxin on the action potential kinetics of frog skeletal muscle

1. The effect of crotoxin on the action potential kinetics of frog (Rana catesbeiana; 60-80 g) skeletal muscle was studied using a modified Ringer solution containing 1.6 mM KCl. 2. Crotoxin affected the kinetics of the action potential in a dose-dependent manner (90 to 460 nM). At 230 nM, crotoxin prolonged the duration of the action potential (from 1.1 +/- 0.1 to 1.6 +/- 0.1 ms) and slowed the rates of depolarization (from 282.0 +/- 7.3 to 196.0 +/- 13.2 V/s) and repolarization (from -81.4 +/- 6.9 to -55.6 +/- 3.8 V/s), in a dose-dependent manner. Its phospholipase subunit (component B) was five times less effective. 3. No effect of crotoxin was observed in the presence of 2.5 mM KCl or when SrCl2 was substituted for CaCl2. Lowering the muscle temperature to 12 degrees C did not reduce the effect of crotoxin. 4. No effect on the passive membrane response to hyperpolarizing current pulses was observed, which implies no major effect on the membrane resistance and capacitance. 5. It is concluded that crotoxin reduces the Na+ current and slows down the repolarization mechanism. This effect is probably not dependent on the phospholipase A2 activity of crotoxin and is inhibited by the substitution of Sr2+ for Ca2+

Effects of a toxic fraction, PhTx2, from the spider Phoneutria nigriventer on the sodium current.

The toxic fraction PhTx2 of the spider Phoneutria nigriventer was studied with a modified loose patch clamp technique on frog skeletal muscle. At saturating concentration (8 micrograms/ml) potassium currents were unaffected whereas there was a 7-fold increase in the time constant of sodium current inactivation (at -13 mV test potential). The time course of tail current deactivation was at least 3-fold slower than the control. The steady state (100 ms) inactivation and the conductance activation were shifted toward more negative potentials by 12.2 and 7.0 mV, respectively. The reversal of the sodium current was shifted 7.6 mV to more negative potential. We conclude that PhTx2 prolongs the inactivation and deactivation processes of sodium ion channels. These effects may account for the toxicity of PhTx2.

[Comparative study of intrauterine devices: TCu380A and Flexigard]. / Estudo comparativo entre os dispositivos intrauterinos: TCu380A e Flexigard.

PIP: The Copper T 380A and the Flexigard intrauterine devices were evaluated for safety, efficacy, and continuation rates in parous women. The Flexigard is a new concept of IUD technology with regard to the affixing of the device to the uterine fundus, the flexibility of the device, and the total absence of a plastic frame. A total of 186 women were enrolled in the study: Group I contained 90 women using Flexigard, and Group II 96 women using TCu380A. All participants were healthy women with at least one living child, regular menstrual cycles, and without previous history of pelvic inflammatory disease and/or ectopic pregnancy. The IUDs were inserted in the first 10 days of the cycle, and subsequent examinations were carried out on day 15, and 3, 6, 9, 12, and 24 months after insertion. The patients were followed up for a total of 2622 and 2589 woman-months for TCu380A and Flexigard, respectively. There were 96 TCu380A and 95 Flexigard insertions. Medical reasons for discontinuation were: desire to get pregnant (1.1%), complaint of partner (1.1%), blood loss (1.1%) for Flexigard; and desire to get pregnant (5.2%), partner's complaint (1.9%), and loss of blood (1.0%) for TCu380A. There were five insertion failures out of 95 insertions with the Flexigard and none out of 96 insertions with TCu380A. The age, parity, and continuation rates showed no differences between devices. The main difference between the devices was that the complete expulsion rate for Flexigard was significantly higher (5.55%) than for the TCu380A (p 0.05). This high rate of complete expulsions for Flexigard was attributable to improper insertion of the device rather than to the expulsion of a properly fitted one.^ieng

The effect of crotoxin on the release of acetylcholine and lactate dehydrogenase from rat brain cortical slices.

1. We have studied the effects of crotoxin, the neurotoxin of the South American rattlesnake Crotalus durissus terrificus, on the release of acetylcholine and lactate dehydrogenase from rat brain cortical slices. 2. Crotoxin enhances the release of [3H]-acetylcholine from cortical slices (control values 92.8 +/- 5.9 and 150.3 +/- 11.7 DPM/mg and crotoxin values 199.1 +/- 7.0 and 336.0 +/- 26.0 DPM/mg, at 60 and 120 min incubation, respectively) in parallel with the release of lactate dehydrogenase (control values 50.4 +/- 16.8 and 80.3 +/- 19.5 U/mg and crotoxin values 162.5 +/- 39.1 and 355.7 +/- 38.2 U/mg, at 60 and 120 min incubation, respectively). Both effects are markedly reduced when substituting Sr2+ for Ca2+ in the incubation medium. 3. It is concluded that the phospholipase activity of crotoxin is responsible for the observed effects.

The effect of crotoxin on the release of acetylcholine and lactate dehydrogenase from rat brain cortical slices

We have studied the effects of crotoxin, the neurotoxin of the South American rattlesnake Crotalus durissus terrificus, ,on the release of acetylcholine and lactate dehydrogenase from rat brain cortical slices. Crotoxin enhances the release of [3H]-acetylcholine from cortical slices (control values 92.8 ñ 5.9 and 150.3 ñ 11.7 DPM/mg and crotoxin valuesw 199.1 ñ 7.0 and 336.0 ñ 26.0 DPM/mg at 60 and 120 min incubation, respectively) in parallel with the release of lactate dehydrogenase (control values 50.4 ñ 16.8 and 80.3 ñ 19.5 U/mg and crotoxin values 162.5 ñ 39.1 and 355.7 ñ 38.2 U/mg, at 120 min incubation, respectively). Both effects are markedly reduced when substituting Sr2+ for Ca2+ in the incubation medium. It is concluded that the phospholipase activity of crotoxin is responsible for the observed effects