Biomedical subjects

J F Rodríguez

Publications and source records attributed to J F Rodríguez.

17 recordsLinked to original sources

PubMed2001

[Total plasma homocysteine concentrations in Puerto Rican patients with ischemic heart disease].

INTRODUCTION AND OBJECTIVES: In Puerto Rico, it has been established that although coronary disease is the leading cause of death, the population has a lower incidence of coronary disease than in the continental United States. In addition, the severity of the disease is less aggressive in terms of a lower incidence of ventricular tachycardia and sudden death. One factor that could contribute to the lower incidence of coronary disease in Puerto Rico is that our population might have lower total plasma homocysteine concentrations (tHcys) than in the continental United States. Our main objective was to measure tHCys in the Puerto Rican population with atherosclerotic cardiovascular disease (ACD). METHODS: We randomly measured tHcys concentrations in seventy Puerto Rican patients who were hospitalized at the Cardiovascular Center of Puerto Rico and the Caribbean (UPR Division). RESULTS: The mean tHCys concentration in these patients is similar to those reported for the Framingham study when adjusted by age (11.2 vs. 11.8 micromol/l). In the Puerto Rican population, males had a higher tHcys concentration than females (11.7 vs 9.5 micromol/l, p = 0.07). In addition, we did not see an increase of tHcys concentrations in diabetic patients when compared with non-diabetics (10.1 vs. 11.2 micromol/l, p = 0.74). We did not see a direct correlation between tHcys concentrations and heart condition as measured by coronary angiography (normal = 11.1 micromol/l, light = 10.5 micromol/l, moderate = 10.9 micromol/l, severe = 10.5 micromol/l; Kruskal-Wallis = 0.45) either. CONCLUSION: These results suggest that tHcys concentration is not a good predictor of the seriousness of ACD in the Puerto Rican patient population.

Female↗

PubMed2001

C terminus of infectious bursal disease virus major capsid protein VP2 is involved in definition of the T number for capsid assembly.

Infectious bursal disease virus (IBDV), a member of the Birnaviridae family, is a double-stranded RNA virus. The IBDV capsid is formed by two major structural proteins, VP2 and VP3, which assemble to form a T=13 markedly nonspherical capsid. During viral infection, VP2 is initially synthesized as a precursor, called VPX, whose C end is proteolytically processed to the mature form during capsid assembly. We have computed three-dimensional maps of IBDV capsid and virus-like particles built up by VP2 alone by using electron cryomicroscopy and image-processing techniques. The IBDV single-shelled capsid is characterized by the presence of 260 protruding trimers on the outer surface. Five classes of trimers can be distinguished according to their different local environments. When VP2 is expressed alone in insect cells, dodecahedral particles form spontaneously; these may be assembled into larger, fragile icosahedral capsids built up by 12 dodecahedral capsids. Each dodecahedral capsid is an empty T=1 shell composed of 20 trimeric clusters of VP2. Structural comparison between IBDV capsids and capsids consisting of VP2 alone allowed the determination of the major capsid protein locations and the interactions between them. Whereas VP2 forms the outer protruding trimers, VP3 is found as trimers on the inner surface and may be responsible for stabilizing functions. Since elimination of the C-terminal region of VPX is correlated with the assembly of T=1 capsids, this domain might be involved (either alone or in cooperation with VP3) in the induction of different conformations of VP2 during capsid morphogenesis.

Animals↗

PubMed2000

First asymmetric hetero Diels-Alder reaction of 1-sulfinyl dienes with nitroso derivatives. A new entry to the synthesis of optically pure 1,4-imino-L-ribitol derivatives.

Hetero Diels-Alder (HDA) cycloaddition of chiral 1-p-tolylsulfinyl-1,3-pentadiene with benzyl nitrosoformate, under mild conditions, yields 2H-1,2-oxazine 3 with complete regioselectivity and pi-facial diastereoselectivity. Sequential osmylation and protection of the resulting glycol gives the oxazine 5 which is directly transformed into enantiomerically pure 1,4,5-trideoxy-1,4-imino-L-ribitol 8 by reduction under Pd/C.

Cyclization↗

PubMed2000

Total plasma homocysteine concentrations in Puerto Rican patients with presumptive atherosclerotic coronary disease.

BACKGROUND: In Puerto Rico, it has been established that although coronary heart disease is the leading cause of death, the population has a lower incidence of coronary disease than the continental United States. In addition, the severity of the disease is less aggressive in terms of a lower incidence of ventricular tachycardia and sudden death. A factor in the lower incidence of coronary disease in Puerto Rico could be a lower total plasma homocysteine concentration (tHcys) in our population. METHODS: We randomly measured tHcys concentrations in seventy-two Hispanic patients who were hospitalized for coronary angiography at the Cardiovascular Center of Puerto Rico and the Caribbean (UPR Division). RESULTS: The mean tHCys concentration in our patient population is similar than that reported for the Framingham study when adjusted by age (11.2 mumol/L vs. 11.8 mumol/L). In the Puerto Rican population, males had a higher tHcys concentration than females but this difference was not statistically significant (10.9 mumol/L vs. 9.4 mumol/L, p = 0.09). In addition, we did not see an increase of tHcys concentrations in diabetic patients when compared with nondiabetics (10.1 mumol/L vs. 10.3 mumol/L, p = 0.73). Neither we saw a direct correlation between tHcys concentrations and atherosclerosis as measured by coronary angiography (normal = 10.9 mumol/L, mild = 8.6 mumol/L, moderate = 10.9 mumol/L, severe = 10.5 mumol/L; ANOVA = 0.29). CONCLUSIONS: These results suggest that tHcys concentration is not a good predictor of atherosclerotic coronary disease in our patient population.

Angiography↗

PubMed1998

Analysis of antiretroviral nucleosides by electrospray ionization mass spectrometry and collision induced dissociation.

Antiretroviral nucleoside drugs used against the human immunodeficiency virus (HIV) infection have been analyzed using negative ion electrospray ionization (ESI) mass spectrometry and collision-induced dissociation (CID-MS/MS). Mass fragmentation of azidothymidine (AZT), didanosine (ddI), dideoxycytidine (ddC) and dideoxythiacytidine (3TC) were obtained at different cone voltages and collision energies. Fragmentation of purines and pyrimidines occurred by different pathways. For purines (ddI), the fragmentation was similar to those found in endogenous nucleosides; mainly the pseudo molecular ion is present (M-H)- and a cleavage through the glycosidic bond forming (B)- was observed. For pyrimidines (AZT, ddC, 3TC), the fragmentation pathways were different from endogenous nucleosides; for AZT, the fragmentation occurred primarily through the elimination of the azido group in the 3'-position (M-H2-N3)-, whereas ddC and 3TC presented more complex fragmentation patterns. For ddC, fragmentation appeared to be dominated by a retro Diels-Alder mechanism (M-CONH)-. For 3TC, the sulfur atom in the sugar moiety provided greater stability to the charge, producing fragments where the charge resided initially in the dideoxyribose (M-C2O2H6)-.

Anti-HIV Agents↗

PubMed1998

Expression of ORF A1 of infectious bursal disease virus results in the formation of virus-like particles.

A recombinant vaccinia virus inducibly expressing ORF A1 of infectious bursal disease virus (IBDV) has been constructed and characterized. Cells infected with this recombinant virus express the IBDV polyprotein, which is proteolytically processed to give mature VP2, VP3, and VP4 polypeptides. An electron microscopy study revealed that the cytoplasm of cells infected with the recombinant virus contains abundant IBDV-like particles (VLP). These VLP form close-packed paracrystalline arrays that are specifically recognized by anti-IBDV antibodies. The size and morphology of purified VLP were found to be akin to those of authentic IBDV particles.

Amino Acid Sequence↗

PubMed1997

Cloning of the gp63 surface protease of Leishmania infantum. Differential post-translational modifications correlated with different infective forms.

The Leishmania cell surface virulence factor gp63 is a protease family that plays an important role in the survival of the parasite protozoon into the host macrophages. We have cloned and characterised the gp63 gene from L. infantum. The sequence analysis of the gene indicates the existence of a high degree of conservation with the other old world species L. major and L. donovani. The similarity is lower with new world species with the exception of L. chagasi which shows a strikingly high percentage of identity (99-100%). In L. infantum the gp63 gene expresses two polypeptides of 58 and 60 kDa, respectively, which show a similar proteolytic activity. The 60 kDa polypeptide is expressed during the whole life cycle of the promastigote form of the parasite with a moderate increase at the stationary phase of growth while the 58 kDa product, although slightly present in the logarithmic phase, notable increases its expression during the highly infectious stationary phase. RNA analysis showed that the presence in L. chagasi of these two polypeptides correlates with two RNA molecules and with the degree of parasite infectivity, whereas in the case of L. infantum a single 3 kb messenger RNA is detected through the whole promastigote life cycle. Our data indicate that in L. infantum, the differences in gene expression of the gp63 protease family according to parasite phase of growth seem to be due to a differential pattern of glycosilation of the polypeptides which correlates with the different infective forms of the promastigote form of the parasite.

Amino Acid Sequence↗

PubMed1997

The major antigenic protein of infectious bursal disease virus, VP2, is an apoptotic inducer.

Infectious bursal disease virus (IBDV) is the causative agent of an economically important poultry disease. Vaccinia virus recombinants expressing the IBDV mature structural capsid proteins VP2 and VP3 were generated by using vectors for inducible gene expression. Characterization of these recombinant viruses demonstrated that expression of VP2 leads to induction of apoptosis in a variety of mammalian cell lines. Transfection of cell cultures with a expression vector containing the VP2 coding region under the control of the immediate-early promoter-enhancer region of human cytomegalovirus also triggers programmed cell death. The apoptotic effect of VP2 is efficiently counteracted by coexpression of the proto-oncogene bcl-2. The results presented demonstrate that VP2 is a bona fide apoptotic inducer. Evaluation of the significance of this finding for the virus life cycle must await further research.

Animals↗

PubMed1997

Azidothymidine triphosphate determination using micellar electrokinetic capillary chromatography.

There is a need to perform pharmacokinetic studies in the pediatric population utilizing antiretroviral drugs, which have shown effectiveness for the treatment of human immunodeficiency virus (HIV). In order to establish a relationship between efficacy and toxicity, we need to detect and quantitate these antiretroviral nucleosides and their metabolites at the intracellular level. Micellar electrokinetic capillary chromatography (MECC) was used for the separation of five nucleotides: cytidine triphosphate (CTP), adenosine triphosphate (ATP), thymidine triphosphate (TTP), guanosine triphosphate (GTP) and azidothymidine triphosphate (AZT-TP). Attomoles of these nucleotides were satisfactorily resolved in short run times with high peak efficiencies. In addition, nanoliters of sample volume were used to perform the analysis using ultraviolet (UV) detection at 254 nm.

Anti-HIV Agents↗

PubMed1995

The African swine fever virus IAP homolog is a late structural polypeptide.

The analysis of the complete nucleotide sequence of the African swine fever virus genome has revealed the existence of a number of genes potentially capable of modifying the host's response to the virus infection. In this report, we describe the results of the characterization of the A224L gene that encodes a novel member of the family of apoptosis inhibitors known as IAP proteins. A224L is expressed during the late phase of the infectious cycle, and its polypeptide product is assembled into virus particles.

African Swine Fever Virus↗

PubMed1995

Vectors for the genetic manipulation of African swine fever virus.

Plasmid vectors designed to facilitate the genetic manipulation of African swine fever virus (ASFV) are described. Our results demonstrate that the beta-glucuronidase enzyme (GUS) can be used to follow gene expression in ASFV-infected cells. Infectious plaques formed by ASFV expressing GUS are visually detectable, thus providing a simple and highly sensitive method for the selection of ASFV recombinants. These and previous results have allowed us to construct two chimeric gene cassettes that constitute the basic tools for the generation of vectors to carry out the deletion of multiple target sequences from the ASFV genome. These cassettes, formed by: (a) a virus promoter; (b) the coding sequence of a reporter gene, either Lac Z or gusA; and (c) a strong signal for the 3' end formation of ASFV mRNAs, can be easily isolated by endonuclease restriction from their corresponding plasmid vectors. A general insertion/coexpression plasmid vector, pEPV2, has also been constructed. pEPV2 facilitates the insertion of foreign genes, together with the Lac Z reporter, into the thymidine kinase locus of ASFV. The functionality of pEPV2 has been tested by generating a recombinant ASFV expressing the luciferase gene. The vectors presented in this report constitute the first reported set of tools for the genetic manipulation of ASFV.

African Swine Fever Virus↗

PubMed1993

The DNA polymerase-encoding gene of African swine fever virus: sequence and transcriptional analysis.

The putative DNA polymerase-encoding gene of African swine fever virus has been sequenced. The gene, designated G1207R, is located in the central region of the viral genome, and encodes a protein of 1207 amino acids (aa) with a predicted M(r) of 139,835. The gene is transcribed at both early and late stages of infection into a 4.1-kb RNA. Transcription is initiated at tsp, 8 nucleotides (nt) upstream from the start codon. Open reading frame (ORF) G1207R contains four direct repeats in tandem close to the 3'-end. Each repeat consists of 12 nt, coding for the reiterated sequence, K/NPAG. The deduced aa sequence of G1207R shows significant similarity with DNA polymerases from cellular and viral origin, belonging to the alpha-like family of DNA polymerases. In particular, the G1207R protein presents a colinear arrangement of all the 3'-->5' exonuclease and polymerization highly conserved aa regions characteristic of this group of DNA-dependent DNA polymerases.

African Swine Fever Virus↗

PubMed1993

Two putative African swine fever virus helicases similar to yeast 'DEAH' pre-mRNA processing proteins and vaccinia virus ATPases D11L and D6R.

Two open reading frames (ORFs) of African swine fever virus (ASFV) encoding putative helicases have been sequenced. The two genes, termed D1133L and B962L, are located in the central region of the viral genome, but are separated by about 40 kb of DNA. Both genes are expressed late during ASFV infection of Vero cells, after replication of viral DNA has begun. Contiguous to D1133L, three other ORFs (D129L, D79L and D339L), encoding putative proteins of unknown function, have been sequenced. Proteins D1133L and B962L contain the amino acid motifs that characterize helicases of superfamily II. D1133L is most similar to a group of putative helicases which includes two proteins of vaccinia virus (D11L and D6R) involved in transcription of the viral genome, their homologues in other poxviruses, the protein encoded by ORF 4 of the yeast plasmids, pGKL2 and pSKL, and the previously identified ASFV protein, Q706L. B962L resembles a group of RNA-helicase-like proteins which includes three proteins of Saccharomyces cerevisiae involved in pre-mRNA splicing (PRP2, PRP16 and PRP22), Drosophila melanogaster KURZ and MLE, and vaccinia virus 18R.

Adenosine Triphosphatases↗

PubMed1993

African swine fever virus thymidylate kinase gene: sequence and transcriptional mapping.

A putative thymidylate kinase gene of African swine fever virus has been identified at the left end of the SalI I' fragment of the virus genome. The gene, designated A240L, has the potential to encode a protein of 240 amino acids with an M(r) of 27,754 and is transcribed early after infection. Primer extension analysis indicates that transcription is initiated a short distance from the first ATG codon of open reading frame A240L. The deduced amino acid sequence of this open reading frame shows significant similarity with the human, yeast and vaccinia virus thymidylate kinases, the degree of identity being 23.7, 25 and 23.5%, respectively. The putative African swine fever virus thymidylate kinase sequence is essentially collinear with the other thymidylate kinase sequences, but contains a carboxy-terminal extension of 37 amino acids rich in glutamic and aspartic acids. The A240L protein conserves the ATP-binding and nucleotide/nucleoside-binding domains characteristic of thymidylate kinases.

African Swine Fever Virus↗

PubMed1992

Keratoconjunctivitis sicca and diabetes mellitus in a dog.

Diabetes mellitus and keratoconjunctivitis sicca were diagnosed in a female Poodle. The dog was treated for diabetes and keratoconjunctivitis sicca until blood glucose concentrations were within normal limits. Treatment for keratoconjunctivitis sicca was suspended then, and signs of this disorder did not appear again. Most of the factors known to predispose to keratoconjunctivitis sicca were not applicable to this dog. On the basis of observations made in this dog, we suggest that diabetes mellitus and keratoconjunctivitis sicca may be linked. Clinical signs of the disorders developed simultaneously and resolved when diabetes mellitus was controlled with insulin.

Animals↗

PubMed1992

Evaluation of total protein content in tears of dogs by polyacrylamide gel disk electrophoresis.

Concentration of total proteins was measured and sodium dodecyl sulfate-polyacrylamide gel disk electrophoresis was performed on tear and plasma samples obtained from 26 healthy dogs, and the results were compared. Mean +/- SEM concentration of total proteins in tears was 0.63 +/- 0.04 g/dl, and significant effects of age or gender were not found. The protein composition of tears in dogs was complex, and bands from light and heavy chains of immunoglobulins were identified by electrophoresis.

Age Factors↗

PubMed1984

The influence of Cervantes on the future creator of psychoanalysis.

Our work is intended to recreate the origins of the 'future creator of psychoanalysis'. Cervantes had a decisive influence on Freud. Don Quixote occupied a central place during a period which we consider to be crucial in the creation of psychoanalysis; we refer to the summer of 1883 during which Freud confessed to Martha that he had become more interested in this book than in brain anatomy. In this work, Cervantes delves in-depth into problems which he had set out in The Colloquy of the Dogs, read by Freud in his adolescence when he was learning Spanish and which confronted some of the great psychoanalytic themes such as reality-fantasy, language, instinct and reason, traumatic situations, 'family romance', etc. These themes appear in a psychoanalytically structured dialogue in which one of the dogs, Berganza, tells his life story (in the form of catharsis) to the other dog, Cipión, with whom Freud identified himself. Basically, it is the psychotherapeutic model that Freud used with his own hysterical patients. Another dialogue which was essential for Freud was that of Don Quixote and Sancho Panza, due to the following major reasons (as well as others): For the clear discrimination between reality and fantasy as well as their interplay. Because madness is presented as a complex phenomenon, but intelligible in terms of human motives. For the penetrating description of the transition in Don Quixote from mania to depression. Because at that moment of his life, Freud himself was living through a personal conflict between his dreams of carrying out some scientific feat and the demands of attending to his mundane necessities.

Austria↗