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J Salinas

Publications and source records attributed to J Salinas.

At least 55 records · Page 3Linked to original sources
PubMed1997

Localization by immunoelectron microscopy of antigens of Chlamydia psittaci suitable for diagnosis or vaccine development.

Two different antigens of serotype 1 Chlamydia psittaci were localized using three immunoelectron microscopy techniques: non-embedding, pre-embedding and post-embedding. The antigens had previously been described as being of potential use in diagnosis (80-90 kDa protein region) and vaccine development (110 kDa protein). The results show a direct relationship between the protective capacity of the antigens and their surface localization on the elementary bodies, which are the infectious form of Chlamydia. The 80-90 kDa protein region is located on the surface of reticulate bodies but not of elementary bodies, where it was located periplasmically, while the 110 kDa protein occurs on the surface of both elementary and reticulate bodies.

Animals↗
PubMed1997

Two homologous low-temperature-inducible genes from Arabidopsis encode highly hydrophobic proteins.

We have characterized two related cDNAs (RCI2A and RCI2B) corresponding to genes from Arabidopsis thaliana, the expression of which is transiently induced by low, nonfreezing temperatures. RCI2A and RCI2B encode small (54 amino acids), highly hydrophobic proteins that bear two potential transmembrane domains. They show similarity to proteins encoded by genes from barley (Hordeum vulgare L.) and wheatgrass (Lophophyrum elongatum) that are regulated by different stress conditions. Their high level of sequence homology (78%) and their genomic location in a single restriction fragment suggest that both genes originated as a result of a tandem duplication. However, their regulatory sequences have diverged enough to confer on them different expression patterns. Like most of the cold-inducible plant genes characterized, the expression of RCI2A and RCI2B is also promoted by abscisic acid (ABA) and dehydration but is not a general response to stress conditions, since it is not induced by salt stress or by anaerobiosis. Furthermore, low temperatures are able to induce RCI2A and RCI2B expression in ABA-deficient and -insensitive genetic backgrounds, indicating that both ABA-dependent and -independent pathways regulate the low-temperature responsiveness of these two genes.

Abscisic Acid↗
PubMed1997

Different roles of flowering-time genes in the activation of floral initiation genes in Arabidopsis.

We have analyzed double mutants that combine late-flowering mutations at four flowering-time loci (FVE, FPA, FWA, and FT) with mutations at the LEAFY (LFY), APETALA1 (AP1), and TERMINAL FLOWER1 (TFL1) loci involved in the floral initiation process (FLIP). Double mutants between ft-1 or fwa-1 and lfy-6 completely lack flowerlike structures, indicating that both FWA and FT act redundantly with LFY to control AP1. Moreover, the phenotypes of ft-1 ap1-1 and fwa-1 ap1-1 double mutants are reminiscent of the phenotype of ap1-1 cal-1 double mutants, suggesting that FWA and FT could also be involved in the control of other FLIP genes. Such extreme phenotypes were not observed in double mutants between fve-2 or fpa-1 and lfy-6 ap1-1. Each of these showed a phenotype similar to that of ap1-1 or lfy-6 mutants grown under noninductive photoperiods, suggesting a redundant interaction with FLIP genes. Finally, the phenotype of double mutants combining the late-flowering mutations with tfl1-2 were also consistent with the different roles of flowering-time genes.

Arabidopsis↗
PubMed1996

Serotype 2-specific antigens from ruminant strains of Chlamydia pecorum detected by monoclonal antibodies.

A panel of 25 monoclonal antibodies (MAbs) selected from seven different cellular fusions was used to study the antigenic relationships among a group of 18 ruminant serotype 2 strains of Chlamydia pecorum by indirect microimmunofluorescence test. The antigenic relationships between the strains of C. psittaci serotype 1 and strains of serotype 2 C. pecorum were also studied, as well as the C. pecorum strains and an avian and a feline strain of C. psittaci. Only the genus-specific MAb, used as a positive control, reacted with all the tested strains. Six MAbs reacted with all the C. pecorum serotype 2 strains, but only one of them recognized an 80 kDa protein in Western blot. With these 18 serotype 2 strains, 16 different patterns were established, underlying the high heterogeneity of this group. Only the three caprine strains exhibited the same profile. None of the MAbs reacted with the serotype I strains, or the feline isolate of C. psittaci, but two of them recognized the avian strain. We discuss the possibility that the serotype 2-specific antigens represent C. pecorum species-specific antigens that could be used for diagnosis.

Animals↗
PubMed1996

Murine granulated metrial gland cells are susceptible to Chlamydia psittaci infection in vivo.

Granulated metrial gland (GMG) cells are the most numerous lymphoid cells in the uteroplacental unit in rodent pregnancy. In an experimental murine model of abortion-causing infection, we have studied the responses of GMG cells to Chlamydia psittaci. Chlamydial inclusions have been found within GMG cells, both in apparently healthy cells and in cells with degenerative changes. Establishing the existence of GMG cells infected by C. psittaci opens a new and interesting chapter in the study of these cells.

Animals↗
PubMed1995

Gonadal steroid hormone-dependence of beta-endorphin-like immunoreactivity in the medial preoptic area of the rat.

Gonadal steroid hormones are known to alter the expression of proopiomelanocortin (POMC) mRNA in neurons of the arcuate nucleus (ARC). These neurons send projections to the medial preoptic area (MPOA), wherein mu-opiate receptor density is cyclical and gonadal steroid hormone-dependent. Although beta-endorphin-(beta-Endo) content in the MPOA is known to vary across the estrous cycle, the effect of gonadal hormones on the distribution and density of beta-Endo-like immunoreactive (IR) fiber density in the preoptic area is unknown. In the present study, immunohistochemical staining was used to investigate the effects of gonadal steroid hormone treatment on beta-Endo-like IR fibers in the MPOA of ovariectomized (OVX) female rats. The density of beta-Endo-like IR fibers was low in the MPOA of OVX rats, but increased slightly following treatment with 17 beta-estradiol (E2) or 3 h after subsequent progesterone (P) injection. However, beta-Endo-like IR fiber density increased significantly 27 h after E2P treatment, and remained elevated 51 h after E2P treatment in the periventricular zone and in the medial portion of the medial preoptic nucleus, although the general distribution of fibers was unchanged. These results suggest that the density of MPOA beta-Endo innervation is normally gonadal steroid hormone-dependent and that the medial MPOA contains greater opioid tone than the lateral MPOA regardless of the hormonal state. Furthermore, since beta-Endo-like IR fiber density remained elevated even though gonadal hormone levels decreased, additional factors might modulate the release or turnover of beta-Endo in the MPOA during normal estrous cycling.

Animals↗
PubMed1995

Antigenic diversity of ruminant Chlamydia psittaci strains demonstrated by the indirect microimmunofluorescence test with monoclonal antibodies.

Monoclonal antibodies (mAbs) were produced to find strain markers essential to the epidemiological study of chlamydial abortion of ruminants. Their specificity was tested on 53 C. psittaci strains including 35 ruminant strains isolated mainly from abortion, belonging to serotype 1 and which are invasive in our mouse model (Rodolakis et al., 1989), and 14 ruminant strains mostly intestinal, belonging to serotype 2 and non-invasive for mouse. One strain specific mAb was obtained reacting only with the non-invasive strain iB1. Six sub serotype 2 mAbs were found. They reacted only with some non-invasive strains. They allowed the distinction of 9 patterns of response among the 14 non-invasive strains. No serotype 2 specific mAbs reacting with all non-invasive serotype 2 strains were selected. In return all the invasive strains reacted with all the 18 serotype 1 specific mAbs produced. No cross-reactivities between invasive and non-invasive strains were observed, whereas common epitopes were demonstrated between invasive strains and avian or feline strains.

Animals↗
PubMed1995

An oligomer of the major outer membrane protein of Chlamydia psittaci is recognized by monoclonal antibodies which protect mice from abortion.

Monoclonal antibodies (MAbs) were generated against an ovine abortive strain of Chlamydia psittaci. A plaque reduction assay was used to select 19 neutralizing antibodies which appeared to be heterogeneous in isotype, specificity, and recognized proteins. Different neutralizing MAbs were tested for their protective abilities against abortion in a pregnant-mouse model. All of the protective MAbs selected had the same isotype, were serotype 1 specific, and recognized a protein of about 110 kDa by immunoblotting. The recognized epitopes were resistant to sodium dodecyl sulfate and reducing agents, but all of them were heat sensitive. The protein was able to form disulfide-linked polymers. Immunological cross-reaction studies with rabbit sera showed a link between the 110-kDa protein and the major outer membrane protein (MOMP). The 110-kDa protein was purified by immunoaffinity and shown to be dissociated after heating into MOMP by silver staining and immunoblotting. These results show homogeneity among protective MAbs directed to heat-sensitive epitopes located on an oligomer of the MOMP of C. psittaci.

Abortion, Veterinary↗
PubMed1995

[Uncoordinated urinary syndrome. New aspects of an old problem].

Uncoordinated voiding, since it was described by F. Hinman in 1973, have remained an ambiguous concept. Its clinical aspects are well known, but an urodynamic definition and therapeutic guidelines are lack. Through this work, we are going to discuss clinical and urodynamic aspects of Uncoordinated Voiding Syndrome, and to evaluate sphincterian re-education techniques in this cases. We present a series of 50 consecutive patients with a diagnosis of Uncoordinated Voiding Syndrome. Mean age was 11.9 years old. There were 82% of female patients and only 18% male patients. A complete urodynamic study was accomplished in all patients, including video-cistometrography and superficial perineal electromiography to confirm the diagnosis. Therapeutic protocol consisted of three steps: 1 Manual pre-micturition training stage. 2. Electromiographic pre-micturition training stage. 3. Micturitional training stage. Most common clinic findings in our series were: enuresis (74%). urge-incontinence (70%), recurrent urinary tract infection (50%), intestinal disturbances (32%) and voiding difficult (20%). Based on our urodynamic findings, we have distinguished three sub-types of Uncoordinated Voiding Syndrome: I Type A, means micturition is achieved through a detrusor involuntary contraction. II. Type B, means micturition is achieved through a detrusor voluntary contraction. III. Type C, means micturition is achieved through abdominal straining. The most important urodynamic data in Uncoordinated Voiding Syndrome was independently of maximum flow, the absence of relaxation or increased perineal electromiographic activity during uroflowmetry. Pressure-flow test was fundamental to characterize Uncoordinated Voiding Syndrome. In our serie, 58% of patients were classified as type A, 28% as type B and 14% as type C. Sphincterian re-education obtained 64% of positive results, with 42% of patients being cured and 29% of them being improved. No result was obtained in 14% of patients. Two percent of patients relapsed after a remission period. Twenty percent of patients were excluded of the study because diverse reasons. Once treatment finished, clinical results remained stable during follow-up.

Adult↗
PubMed1994

Coordinate expression of antibody subunit genes yields high levels of functional antibodies in roots of transgenic tobacco.

To explore the feasibility of employing antibodies to obtain disease resistance against plant root pathogens, we have studied the expression of genes encoding antibodies in roots of transgenic plants. A model monoclonal antibody was used that binds to a fungal cutinase. Heavy and light chain cDNAs were amplified by PCR, fused to a signal sequence for secretion and cloned behind CaMV 35S and TR2' promoters in a single T-DNA. The chimeric genes were cloned both in tandem and in a divergent orientation. The roots of tobacco plants transformed with these constructs produced antibodies that were able to bind antigen in an ELISA. Immunoblotting showed assembly to a full-size antibody. In addition, a F(ab')2-like fragment was observed, which is probably formed by proteolytic processing. Both antibody species were properly targeted to the apoplast, but the full-size antibody was partially retained by the wall of suspension cells. The construct with divergent promoters showed a better performance than the construct with promoters in tandem. It directed the accumulation of functional antibodies to a maximum of 1.1% of total soluble protein, with half of the plants having levels higher than 0.35%. The high efficiency of this construct probably results from coordinated and balanced expression of light and heavy chain genes, as evidenced by RNA blot hybridization.

Amino Acid Sequence↗
PubMed1994

Two related low-temperature-inducible genes of Arabidopsis encode proteins showing high homology to 14-3-3 proteins, a family of putative kinase regulators.

We have isolated two Rare Cold-Inducible (RCI1 and RCI2) cDNAs by screening a cDNA library prepared from cold-acclimated etiolated seedlings of Arabidopsis thaliana with a subtracted probe. RNA-blot hybridizations revealed that the expression of both RCI1 and RCI2 genes is induced by low temperature independently of the plant organ or the developmental stage considered. However, RCI1 mRNA accumulates faster and at higher levels than the RCI2 one indicating that these genes have differential responsiveness to cold stress. Additionally, when plants are returned to room temperature, RCI1 mRNA decreases faster than RCI2. In contrast to most of the cold-inducible plant genes characterized, the expression of RCI1 and RCI2 is not induced by ABA or water stress. The nucleotide sequences of RCI1 and RCI2 cDNAs predict two acidic polypeptides of 255 and 251 amino acids with molecular weights of 29 and 28 kDa respectively. The alignment of these polypeptides indicates that they have 181 identical amino acids suggesting that the corresponding genes have a common origin. Sequence comparisons reveal no similarities between the RCI proteins and any other cold-regulated plant protein so far described. Instead, they demonstrate that the RCI proteins are highly homologous to a family of proteins, known as 14-3-3 proteins, which are thought to be involved in the regulation of multifunctional protein kinases.

14-3-3 Proteins↗
PubMed1994

The LPS localization might explain the lack of protection of LPS-specific antibodies in abortion-causing Chlamydia psittaci infections.

Four monoclonal antibodies against chlamydial lipopolysaccharide (LPS) were used to study their localization and distribution in the Chlamydia psittaci AB7 abortion-causing strain by immunoelectron microscopy. A non-embedding technique on whole chlamydiae, together with a post-embedding technique on McCoy cells infected with the strain, were performed. Immunogold labelling was observed on the surface of reticular bodies (RB), but not on elementary bodies (EB). Immunolabelling was observed in ultrathin sections on both sides of the external chlamydial membrane, mainly on the inner side of EB and on the outer side of RB. Immunogold density was higher in EB than in RB; however, the absolute number of gold particles was higher in RB than EB, suggesting a loss of immunolabelling during the transformation of RB into EB. Specific labelling of LPS was also found in electrodense and adielectronic vacuoles near the surface of the cytoplasmic membrane of infected McCoy cells. These results suggest that the lack of protection against some chlamydial strains, despite the presence of anti-LPS specific antibodies, is due to the localization of LPS on the inner side of the external membrane of EB.

Abortion, Veterinary↗
PubMed1994

Identification of subspecies- and serotype 1-specific epitopes on the 80- to 90-kilodalton protein region of Chlamydia psittaci that may be useful for diagnosis of chlamydial induced abortion.

Genus-, subspecies-, and serotype 1-specific antigens of Chlamydia psittaci were characterized by immunoblot analysis, using monoclonal antibodies that recognize 2 C psittaci strains: AB7 isolated from an ewe that had aborted, and iB1 isolated from feces of a healthy ewe. Genus-specific epitopes were detected on lipopolysaccharide, on a 47-kd protein, and on a 27- to 30-kd doublet. Subspecies-specific epitopes were located on a 30-kd protein, and a 80- to 90-kd protein region was identified, which bore subspecies- and serotype 1-specific epitopes. These 80- to 90-kd proteins were highly reactive with serum from ewes that had aborted and could be a useful antigen for diagnosis of chlamydial induced abortion of ruminants.

Abortion, Veterinary↗
PubMed1994

[Primary health care and community participation: strategic approaches].

This article gives technical orientation to health institutions for the promotion of community participation and sets forth the challenge of constructing a health system for Chile, according to the needs and problems of the country and based on the principles of solidarity, equity and social participation. It presents the governmental objectives and actions towards the development of social participation as an axis of Primary Care. The adoption of this concept requires a change in health teams internal management and relationship with the local community. The formation of interdisciplinary work groups, the formulation of a community health program, a work based in specific projects and the establishment of an operational sequence are suggested as requirements to start this process.

Chile↗
PubMed1993

Non-random distribution of transposable elements in the nuclear genome of plants.

We have studied the genomic distribution of five different families of plant transposable elements by analyzing their location in DNA fractions from maize and tobacco genomes fractionated according to base composition. The results show that each family of elements is preferentially integrated in one specific fraction of its respective host genome. This demonstrates that the distribution of transposable elements in the nuclear genome of plants is not random but compartmentalized, i.e., the elements are located in specific genomic compartments characterized by having a specific G+C content and representing a small proportion of the genomes. Furthermore, these compartments seem to correspond to the genomic regions where most of the plant genes are also located, suggesting a preferential integration of transposable elements in the transcriptionally active regions of the plant genome. The implications of these results on the current applications of transposon tagging techniques are discussed.

Base Composition↗
PubMed1993

Comparison of thromboelastography to bleeding time and standard coagulation tests in patients after cardiopulmonary bypass.

This prospective study of 36 adult patients undergoing cardiopulmonary bypass (CPB) was conducted to determine the utility of thromboelastography (TEG) versus platelet studies (bleeding time, platelet count, mean platelet volume) and standard coagulation tests (prothrombin time, activated partial thromboplastin time, fibrinogen) to more effectively discriminate patients likely to benefit from platelet or fresh frozen plasma (FFP) transfusion. Although the sensitivities of the bleeding time (71.4%) and platelet count (100%) were similar to the TEG (71.4%), the specificity (89.3%) of the TEG was greater than that of the bleeding time (78.5%) and platelet count (53.6%). Seven patients experienced clinically significant hemorrhage; 5 (71.4%) had an abnormal TEG. Three of 8 (38%) other patients with an abnormal TEG had no abnormal bleeding. Only 2 of 27 (7.4%) patients with a normal TEG had abnormal bleeding requiring platelet or FFP transfusion. Therefore, it is suggested that post-CPB patients with a normal TEG should not receive platelet or FFP transfusions empirically. If excessive bleeding is noted in a patient with a normal TEG, this suggests a surgically correctable etiology. Data from this series suggest that patients displaying an abnormal TEG appear to be at increased risk for hemorrhage; therefore, appropriate blood product support should be initiated at the first sign of accelerated bleeding.

Adolescent↗
PubMed1993

Comparison of different serological methods for the determination of antibodies to Chlamydia psittaci in pigeon sera.

Several methods for detecting antibodies to Chlamydia psittaci using sera from pigeons were compared with regard to their sensitivity, specificity and efficacy. The reference method used was indirect immunofluorescence (IFI), which uses as antigen intracellular inclusions in McCoy cell monolayers. Indirect micro-immunofluorescence (MIF) using as antigen C. psittaci cultured on yolk sacs of embryonated eggs, direct and indirect complement fixation tests (CFT and ICFT, respectively), and enzyme-linked immunosorbent assay (ELISA) were compared to the reference method. Indirect micro-immunofluorescence proved to be the most efficient method, while ELISA was the most sensitive, though showing a very low specificity. No statistically significant difference was found in comparing the two complement fixation tests. The use of ICFT to check for the negative results obtained in CFT is questioned. Possible reasons for the different results with the methods used are discussed.

Animals↗