Unraveling Azospirillum's colonization ability through microbiological and molecular evidence.

It is known that members of the bacterial genus Azospirillum can promote the growth of a great variety of plants, an ability harnessed by the industry to create bioproducts aimed to enhance the yield of economically relevant crops. Its versatile metabolism allows this bacterium to adapt to numerous environments, from optimal to extreme or highly polluted. The fact of having been isolated from soil and rhizosphere samples collected worldwide and many other habitats proves its remarkable ubiquity. Azospirillum rhizospheric and endophytic lifestyles are governed by several mechanisms, leading to efficient niche colonization. These mechanisms include cell aggregation and biofilm formation, motility, chemotaxis, phytohormone and other signaling molecules production, and cell-to-cell communication, in turn, involved in regulating Azospirillum interactions with the surrounding microbial community. Despite being infrequently mentioned in metagenomics studies after its introduction as an inoculant, an increasing number of studies detected Azospirillum through molecular tools (mostly 16S rRNA sequencing) as part of diverse, even unexpected, microbiomes. This review focuses on Azospirillum traceability and the performance of the available methods, both classical and molecular. An overview of Azospirillum occurrence in diverse microbiomes and the less-known features explaining its notorious ability to colonize niches and prevail in multiple environments is provided.

P97/VCP ATPase inhibitors can rescue p97 mutation-linked motor neuron degeneration.

Mutations in p97/VCP cause two motor neuron diseases: inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia and familial amyotrophic lateral sclerosis. How p97 mutations lead to motor neuron degeneration is, however, unknown. Here we used patient-derived induced pluripotent stem cells to generate p97 mutant motor neurons. We reduced the genetic background variation by comparing mutant motor neurons to its isogenic wild type lines. Proteomic analysis reveals that p97R155H/+ motor neurons upregulate several cell cycle proteins at Day 14, but this effect diminishes by Day 20. Molecular changes linked to delayed cell cycle exit are observed in p97 mutant motor neurons. We also find that two p97 inhibitors, CB-5083 and NMS-873, restore some dysregulated protein levels. In addition, two p97 inhibitors and a food and drug administration-approved cyclin-dependent kinase 4/6 inhibitor, Abemaciclib, can rescue motor neuron death. Overall, we successfully used iPSC-derived motor neurons, identified dysregulated proteome and transcriptome and showed that p97 inhibitors rescue phenotypes in this disease model.

Mastocitoma felino. Reporte de caso / Feline mastocytoma. Case report

RESUMEN Los mastocitomas son tumores originarios de los mastocitos que usualmente afectan a los perros y los gatos. Pueden llegar a tener un comportamiento benigno, sin embargo, esto dependerá del grado de la neoplasia y su estadiaje. En felinos, clínicamente se han descrito dos patrones: visceral y cutáneo, de los cuales el cutáneo es el más frecuente, llegando a causar metástasis a órganos adyacentes e incluso afectar el bazo y/o intestino en estadios más diferenciados. Se presenta un caso de mastocitoma felino correspondiente a un ejemplar mestizo con cuadro clínico de inicio de más de dos meses de evolución, consistente en la aparición de una placa alopécica ulcerada y elevada en región interescapular, acompañada de prurito que presentó resolución espontánea. Mediante el curso clínico se imnunizó contra el virus de la rabia, posteriormente, se observó la aparición de una lesión nodular subcutánea de características inusuales de 2cm de diámetro. Acorde con el tiempo de evolución y el antecedente vacunal se decidió la realización de biopsia y resección quirúrgica. El reporte de la biopsia confirmó diagnóstico de mastocitoma grado histológico 3 de Patnaik, teniendo en cuenta las características histológicas, estructurales y su comportamiento clínico. Se realizó seguimiento del caso pasados ocho meses, donde se evidenció mejoría del cuadro clínico, sin aparición de nueva masa sugestiva de neoplasia, sin hallazgos de metástasis a otras estructuras, con cicatrización exitosa de herida quirúrgica y evolución satisfactoria.

ABSTRACT Mast cells are tumors originating from mast cells which usually affect cats and dogs. They may have benign behavior, however, this will depend on the degree of the neo-plasm and its staging. In cats, two patterns have been described clinically: visceral and cutaneous, of which the cutaneous form is the most frequent, reaching metastasis to adjacent organs and even affecting the spleen and / or intestine in more differentiated stages. A case of a mastocytoma is presented, a feline corresponding to a mongrel specimen with a clinical picture of onset of more than two months of evolution, consisting of the appearance of an allopecal plaque, ulcerated and elevated in the interscapular region, accompanied by pruritus that presented spontaneous resolution. Through the clinical course, he was immunized against the rabies virus, later the appearance of a nodular lesion of unusual subcutaneous characteristics, 2 cm in diameter, was observed. According to the evolution time and the vaccination history, it was decided to perform a biopsy and surgical resection. The biopsy report confirmed the diagnosis of Patnaik's histological grade 3 mastocytoma, taking into account the histological and structural characteristics and its clinical behavior. The case was followed up after eight months, where an improvement in the clinical picture was evident, without the appearance of a new mass suggestive of neoplasia, without metastatic findings to other structures, with successful healing of the surgical wound and satisfactory evolution.

Validation of SenseWear Armband in children, adolescents, and adults.

SenseWear Armband (SW) is a multisensor monitor to assess physical activity and energy expenditure. Its prediction algorithms have been updated periodically. The aim was to validate SW in children, adolescents, and adults. The most recent SW algorithm 5.2 (SW5.2) and the previous version 2.2 (SW2.2) were evaluated for estimation of energy expenditure during semi-structured activities in 35 children, 31 adolescents, and 36 adults with indirect calorimetry as reference. Energy expenditure estimated from waist-worn ActiGraph GT3X+ data (AG) was used for comparison. Improvements in measurement errors were demonstrated with SW5.2 compared to SW2.2, especially in children and for biking. The overall mean absolute percent error with SW5.2 was 24% in children, 23% in adolescents, and 20% in adults. The error was larger for sitting and standing (23%-32%) and for basketball and biking (19%-35%), compared to walking and running (8%-20%). The overall mean absolute error with AG was 28% in children, 22% in adolescents, and 28% in adults. The absolute percent error for biking was 32%-74% with AG. In general, SW and AG underestimated energy expenditure. However, both methods demonstrated a proportional bias, with increasing underestimation for increasing energy expenditure level, in addition to the large individual error. SW provides measures of energy expenditure level with similar accuracy in children, adolescents, and adults with the improvements in the updated algorithms. Although SW captures biking better than AG, these methods share remaining measurements errors requiring further improvements for accurate measures of physical activity and energy expenditure in clinical and epidemiological research.

Content of cardiolipin of the membrane and sensitivity to cationic surfactants in Pseudomonas putida.

AIMS: To establish the role of cardiolipin (CL) of the membrane in response to the presence of tetradecyltrimethylammonium in Pseudomonas putida A (ATCC 12633). METHODS AND RESULTS: Two ORFs of Ps. putida A (ATCC 12633), which in Ps. putida KT2440 encode the putative CL synthase genes cls and cls2, were cloned, sequenced and mutated. Only the double mutant lacking cls and cls2 showed a reduction of the CL content, 83% lower than the amount produced by the wild-type. Accompanying this change was a 40% decrease in the content of unsaturated fatty acid. Consequently, the membrane of the mutant was more rigid than the one of the parental strain, as observed using fluorescence polarization techniques. The mutant strain showed reduced viability in the presence of tetradecyltrimethylammonium. The incorporation of exogenous CL into its membrane relieved sensitivity to the cationic detergent. CONCLUSIONS: Pseudomonas Putida cells with low levels of CL die in the presence of tetradecyltrimethylammonium, because they cannot counter the fluidizing effect of the cationic surfactant. SIGNIFICANCE AND IMPACT OF THE STUDY: The modification in the membrane phospholipids composition allows knowing the adaptation strategy of Ps. putida when these bacteria are exposed to cationic surfactant.

Synthesis, structural, magnetic and phase-transition studies of the ferromagnetic La2CoMnO6 double perovskite by symmetry-adapted modes.

A powdered La2CoMnO6 double perovskite was synthesized by the solid-state reaction method, and its crystal structure was investigated by (mode-crystallography) Rietveld analysis using X-ray and neutron powder diffraction data. La2CoMnO6 material is a monoclinic perovskite at room temperature, adopting the space group P21/n (a(-)a(-)b(+)), , c ≈ 2ap and Z = 2. The P21/n phase can be described effectively by three distortion modes (GM4(+), X3(+), X5(+)) of the Fm3[combining macron]m (a(0)a(0)a(0)) parent phase. The comparative study of the material and those in the Ln2CoMnO6 and Ln2NiMnO6 families has shown a general trend in nearly all the materials, has served to select a common direction in the sub-space spanned by X5(+), tri-linearly coupled to the order parameters of the cubic to monoclinic first order phase transition. This direction has been used to parametrize the refinements and to perform reliable refinements in the high-temperature intermediate distorted trigonal phase, R3[combining macron] (a(-)a(-)a(-)), for which only one effectively acting irrep has been deduced: GM5(+), physically a tilt of the oxygen sharing octahedra of Co and Mn. Its temperature evolution up to the prototype cubic phase has been fitted in the framework of the Landau Theory of Phase Transitions, showing a behavior typical of a tricritical point. The low-temperature neutron powder diffraction data have served to solve the magnetic structure: three indistinguishable ferromagnetic models with the space groups P21/n and P2/n' are proposed.

PRIMER REPORTE DE Cryptosporidium parvum EN TERNEROS HOLSTEIN (Bos taurus) DE MANIZALES, CALDAS, COLOMBIA / FIRST REPORT OF Cryptosporidium parvum IN HOLSTEIN CALVES (Bos taurus) FROM MANIZALES, CALDAS, COLOMBIA

El objetivo de este estudio fue identificar especies o genotipos del protozoario parásito Cryptosporidium presentes en heces colectadas de terneros Holstein del municipio de Manizales, Departamento de Caldas, Colombia. El ADN fue extraído a 80 muestras de materia fecal, de las cuales 11 fueron diagnosticadas positivas para Cryptosporidium spp., mediante reacción en cadena de la polimerasa (PCR). El análisis PCR-RFLP del locus 18S ADNr, identificó la presencia de Cryptosporidium parvum en todas las muestras positivas analizadas. Este hallazgo sugiere que el ganado puede ser una fuente potencial de infección por Cryptosporidium en humanos y se constituye en el primer reporte publicado de C. parvum en bovinos de Manizales, Caldas.

The objective of this study was to identify species or genotypes of Cryptosporidium parasite present in feces collected from Holstein calves in Manizales city, Caldas Department, Colombia. DNA was extracted from 80 fecal samples, which 11 were diagnosed positive for Cryptosporidium spp., by the Polymerase Chain Reaction method. PCR-RFLP analysis of 18S rDNA locus identified the presence of Cryptosporidium parvum in all samples tested positive. This finding suggests that cattle may be a potential source of human infection by Cryptosporidium, and it becomes the first published report of C. parvum in cattle in Manizales, Caldas.

Growth and characterization of Pb3Ni1.5Mn5.5O15 single crystal.

Single crystals of the mixed valence compound Pb3Ni1.5Mn5.5O15 were successfully grown. Polarized Raman spectroscopy revealed that they belong to the point group D(3d), in accordance with single-crystal x-ray diffraction data which were refined within the trigonal space group P3c1 (No. 165), with lattice parameters a = 9.941(3) Å and c = 13.543(3) Å. Strongly anisotropic long range magnetic order is established below 65 K.

Upper gastrointestinal bleeding: risk factors for mortality in two urban centres in Latin America.

OBJECTIVE: To describe the experience with upper gastrointestinal bleeding in two major Latin American hospitals; presenting its main causes, treatment, and prognosis, while exploring some risk factors associated with death. DESIGN: Prospective cohort study. PATIENTS AND METHODS: Four hundred and sixty four patients were admitted into any of the 2 hospitals and were at least 15 years of age. Some variables demographics, clinics and treatment were studied. The association between those variables and the death were explored. RESULTS: Mean age was 57.9 years; the men:women ratio was 1.4:1. Three hundred and fifty nine patients (77.3%) presented as outpatients and 105 patients (22.6%) were inpatients presenting with UGIB. 71.6% of patients had an upper GI endoscopy within 24 hours. The main causes of bleeding were peptic ulcer (190 patients, 41%), erosive disease (162 patients, 34.9%) and variceal bleeding (47 patients, 10.1%). Forty four patients died (9.5%). Bleeding as an inpatient has a higher mortality risk than does bleeding as an outpatient (RR 2.4 IC 95% 1.2-4.6). An increasing number of comorbidities such as those described in the Rockall Score are also associated with a higher risk of dying (RR 2.5 IC 95% 1.1-5.4). CONCLUSION: UGIB as an inpatient and the presence of comorbidities should alert the clinician in identifying patients at higher risk of a fatal outcome, these patients should have a more aggressive management and be entitled to an early intervention.

Differential anthracycline sensitivity in two related human colon carcinoma cell lines expressing similar levels of P-glycoprotein.

Chemosensitivity of the human colon carcinoma HCT-15 cell line to 4'-epidoxorubicin proved to be 100-fold higher than that of its variant HCT-15 EDR. Confocal scanning microscopy showed significant less drug accumulation in HCT-15 EDR. A 2-fold increase in hsp27 expression was found in HCT-15 EDR, with no alteration in hsp70. The expression of the drug exporter Pgp was similar in both cell lines, despite the lower drug accumulation shown by HCT-15 EDR in respect to HCT-15. Other molecules implicated in the acquisition of enhanced chemoresistance or a more active Pgp variant present in HCT-15 EDR, could explain the phenomenon.

F1 hybrid inviability in eucalyptus: the case of E. ovata x E. globulus.

The impact of inbreeding and hybridization on fitness was compared in the two co-occurring forest tree species, Eucalyptus ovata and E. globulus, aimed at explaining the rarity of their hybrids in nature. The success of selfing, open-pollination and outcrossing of both species and interspecific hybridization was monitored from seed-set to 10-year's growth in a field trial. There was a unilateral barrier to hybridization with seed-set obtained only with E. ovata females. The F1 hybrids exhibited reduced viability compared to intraspecific cross-types at virtually all stages of the life cycle and are clearly at a selective disadvantage compared with their open-pollinated E. ovata half-sibs with which they would directly compete in nature. Eucalyptus ovata and E. globulus overlap in their flowering time but the F1 hybrids flowered later with virtually no overlap with either species. The asynchronous flowering and reduced reproductive fitness of F1 hybrids would markedly limit the opportunity for advanced generation hybridization. Inbreeding similarly had a deleterious effect on the fitness of both species, and the F1 hybrids were most competitive with the E. ovata selfs. It is argued that changes in inbreeding levels of parental populations may be a key factor affecting the relative fitness of hybrids and their potential to impact on the pure species gene pool. Reduced fitness of the pure species through inbreeding may result in hybridization having its greatest evolutionary impact in small founder or relict populations.

Update on therapies for acute ischemic stroke.

Acute ischemic stroke is now considered a neurological emergency for which there are new therapies. Neurosurgeons and neurologists need to remain apprised of advances in this field. The authors discuss approved and emerging therapies for patients suffering from acute ischemic stroke, based on a review of recent publications. Currently, intravenous tissue-type plasminogen activator is the only Food and Drug Administration-approved therapy for acute ischemic stroke. Intraarterial delivery of thrombolytics is a promising treatment and may be effective in selected patients. Other therapies for acute cerebral ischemia are intriguing but still in the investigational stages.

Changes in various plasma lipid components, glucose, and insulin in Spermophilus lateralis during hibernation.

This study evaluated fat mobilization as related to gluconeogenesis in two age groups of hibernating golden-mantled ground squirrels (Spermophilus lateralis). Our experimental group consisted of a total of 16 male and 15 female squirrels. Plasma samples were collected from selected animals being killed weekly from January to March, and the concentration of triglycerides, glycerol (GY), free fatty acids (FFA), total cholesterol, lipase activity, glucose, and insulin, were determined by biochemical assays and radioimmunoassay. Our results showed a mean FFA/GY ratio of five, which was higher than the predicted value of three, suggesting a significant depletion of GY and an enhanced rate of gluconeogenesis via GY to maintain glucose homeostasis in the hibernating animals. The factor of age did not significantly affect plasma lipid components. However, in the male group, plasma glucose levels were significantly higher for adults than for juveniles. Overall, females had significantly higher plasma glucose levels than males (150 +/- 11 vs. 110 +/- 8 mg%, P < 0.05). In the adult group, a gender influence was also seen on plasma insulin levels, with females' being higher than males' (66 +/- 13 vs. 25 +/- 3 microIU/ml, P < 0.01). We suggest that during hibernation, female squirrels may have a higher rate of lipolysis and gluconeogenesis along with a lower glucose utilization than their male counterparts. Additionally, adult females may exhibit a higher peripheral insulin resistance during hibernation than adult males, a possibility which merits further study.

Evidence that the S6 segment of the Shaker voltage-gated K+ channel comprises part of the pore.

Potassium channels are highly selective and allow the rapid flux of potassium ions through their pore. Several studies have implicated the H5 (P or SS1-SS2) segment as part of the pore in voltage-gated ion channels. The proposal that H5 spans at least 80% of the electric potential drop across the K+ channel pore is based on altered internal tetraethylammonium sensitivity arising from mutations of H5 residues that are 100% conserved among K+ channels having differing sensitivity to tetraethylammonium. Here we report that the S6 segment is also involved in K+ ion permeation and in governing the sensitivity to internal tetraethylammonium and barium. Transplanting the S6 segment of NGK2 into Shaker causes this S6 chimaera to adopt the single-channel conductance and sensitivity to internal tetraethylammonium and barium ions from the NGK2 channel. The differences between NGK2 and Shaker in external tetraethylammonium sensitivity, but not single-channel conductance, can be attributed to the differences in their H5 sequences. Three nonconserved S6 residues have been found to affect either single-channel conductance or internal tetraethylammonium sensitivity.

Plasma lipoprotein cholesterol concentrations in the golden-mantled ground squirrel (Spermophilus lateralis): a comparison between pre-hibernators and hibernators.

1. The concentrations of total cholesterol (free cholesterol plus cholesteryl ester) in the plasma and in two lipoprotein fractions of golden-mantled ground squirrels (Spermophilus lateralis) were measured during pre-hibernation and compared to those values measured during hibernation. 2. Hibernating ground squirrels had significantly higher (P less than 0.005) very low density lipoprotein plus low density lipoprotein cholesterol (VLDL + LDL-C) concentrations than did pre-hibernating ground squirrels. 3. Hibernating squirrels additionally exhibited significantly higher (P less than 0.005) total plasma cholesterol concentration per high density lipoprotein cholesterol concentration (TPC/HDL-C) ratios than did pre-hibernating squirrels. 4. The significant differences in the lipoprotein cholesterol concentrations observed in this study suggest that lipoprotein metabolism in pre-hibernators was significantly different from that in hibernators and was a reflection of the marked biochemical and physiological adjustments these animals must undergo during their transition from pre-hibernation to hibernation.

Gender influences the in vitro renin release responses to dopamine and adrenergic receptor blockade in the summer-active ground squirrel Spermophilus lateralis.

1. 10(-4) M Dopamine stimulated and 10(-7) M inhibited in vitro resting renin release (RR) only in the female animals. 2. Alpha- or beta-adrenergic blockade prevented the stimulation but not the inhibition of RR by dopamine in the female animals. 3. Membrane receptor mechanisms mediating these changes do not involve alterations in tissue cyclic AMP content. 4. The sensitivity of the juxtaglomerular cells to dopamine challenge is gender dependent during summer activity.

[A year of work with adolescents]. / Un ano de trabajo con adolescentes.

PIP: Among objectives of PROFAMILIA's Center for Youth in Bogota were to provide information and education to adolescents and their teachers on prevention of adolescent pregnancy and of sexually transmitted diseases as well as on sexuality and adolescence. Nearly 18,500 adolescents participated in information and education sessions in the Center's 1st year. Nearly 500 teachers participated with their students, and another 197 received training in a workshop on prevention of adolescent pregnancy. The great demand for information and education services on the part of schools and institutions working directly with adolescents demonstrates the need to train educators in the areas of sexuality and family planning. 211 adolescents aged 13-19 participated in workshops to train multipliers to provide a message of sexual responsibility in an informal atmosphere to their peers and classmates. In the 1996 sessions held in the 1st year, a high proportion of adolescents were encountered who feared they were pregnant. Although they had obviously received some information on human reproduction, it did not have a positive or permanent effect in deterring early and unprotected sexual relations. The Center for Youth aspires to replace the usual biological focuses on sexuality with a training in sexuality in which adolescents in grades 6-8, who are 13-15 years old, will receive information and participate in activities stressing self esteem, family communication, decision making, and prevention of pregnancy and sexually transmitted diseases. 53% of the 861 pregnancy tests requested by adolescent participants were positive. Adolescents requesting pregnancy tests shared characteristics such as absence of the father from the household, deficient family communications, lack of affection, low self esteem, and little knowledge or use of contraception. The great majority of these pregnancies were unwanted. Adolescents frequently somaticize their personal, family, and social conflicts and have other specific health needs. They require a more personal kind of medical care that would allow the true causes of their complaints to be identified. PROFAMILIA is considering creating centers especially for adolescents. 4 programs in existing PROFAMILIA clinics have been created to provide educational and medical attention to adolescents as well as educational activities in their schools.^ieng

Characterization of a mammalian cDNA for an inactivating voltage-sensitive K+ channel.

A cDNA clone encoding a K+ channel polypeptide with 72% amino acid sequence identity to Drosophila Shal was isolated from rat hippocampus. Functional expression of the cDNA in Xenopus oocytes generated 4-amino-pyridine-sensitive K+ channels displaying rapid inactivation kinetics. The fastest component of inactivation was slowed by the deletion of 3 basic residues in the amino-terminal region. Northern blots revealed that the mRNA encoding this K+ channel polypeptide was expressed at a similar level in the brain and in the heart. In situ hybridization revealed that the mRNA encoding this K+ channel appeared concentrated in the hippocampus, dentate gyrus, and habenular nucleus in the brain. Thus, this K+ channel polypeptide is likely to form some of the A-type K+ channels expressed in the mammalian nervous system and heart.

Hydrophobic substitution mutations in the S4 sequence alter voltage-dependent gating in Shaker K+ channels.

Voltage-activated Na+, Ca2+, and K+ channels contain a common motif, the S4 sequence, characterized by a basic residue at every third position interspersed mainly with hydrophobic residues. The S4 sequence is proposed to function as the voltage sensor and to move in response to membrane depolarization, triggering conformational changes that open the channel. This hypothesis has been tested in previous studies which revealed that mutations of the S4 basic residues often shift the curve of voltage dependence of activation along the voltage axis. We find that comparable or larger shifts are caused by conservative substitutions of hydrophobic residues in the S4 sequence of the Shaker K+ channel. We suggest that the S4 structure plays an essential role in determining the relative stabilities of the closed and open states of the channel.