Clinical manifestations and vascular events in patients with lupus erythematosus anticardiolipin antibodies and raynaud's phenomenon

BACKGROUND: Raynaud's phenomenon (RP) and anticardiolipin antibodies (ACL) are two common clinical manifestations in patients with systemic lupus erythematosus (SLE). RP may lead to digital or limb loss. ACL are associated to thrombotic episodes. It is not yet clear if there is an association between RP and the presence of ACL in patients with SLE. OBJECTIVES: To study if the presence of both RP and ACL in patients with SLE may be associated with certain clinical manifestations or thrombotic events compared to SLE patients without RP or ACL. METHODS: SLE patients from two lupus clinics were recruited. The patients were divided into 4 groups. Patients with RP and positive ACL (RP+ ACL+), patients with RP but negative ACL (RP+ ACL-), patients with negative RP and positive ACL (RP- ACL+), and patients that were negative for RP and ACL (RP- ACL-) used as the control group. Demographic data, diagnostic criteria, clinical manifestations, history of arterial thrombosis, venous thrombosis and abortions were recorded. A physical examination was done. Anticardiolipin antibodies IgG and IgM were done in the rheumatology laboratory at the University of Puerto Rico School of Medicine. Descriptive statistics as well as analysis of variances (ANOVA), and polytomous logistic regression were used. RESULTS: 236 patients with SLE were studied. There was a tendency toward an increase in arterial thrombosis (p-value = 0.094) and venous thrombosis (p-value = 0.067) in the group that were positive for RP and ACL (RP+ ACL+). Although it was not statistical significant, when polytomous logistic regression was used, both arterial and venous thrombosis had an increase in relative risk 3.21 for arterial and 3.11 for venous thrombosis. Abortions were not increased in any of the four groups. Clinical manifestations from SLE did not differ among the four groups. CONCLUSIONS: Patients with both RP and ACL seem to be at an increase risk for both arterial and venous thrombotic events; these patients may benefit from an antiplatelet medication to prevent these events to occur.

Mortality study in Puerto Ricans with systemic lupus erythematosus.

OBJECTIVE: To determine the most common causes of death among Puerto Ricans with systemic lupus erythematosus. METHODS: Chart and record review of all deaths related to SLE complications from 1960 to 1994 at the University of Puerto Rico Hospital. RESULTS: Out of 662 patients diagnosed with SLE 161 (24%) died. There were 151 (94%) females and 10 (6%) males. Mean duration of disease was 11.5 years. Mean age at death was 37 years. The primary causes of death were infection in 44 (27%), uremia in 42 (26%), cardiovascular complications in 33 (20%), central nervous system complications in 18 (11%), and pulmonary complications (other than infectious pneumonia) in 12 (7%). CONCLUSIONS: The most common causes of death in SLE were infections and renal disease.

[Prevalence of antiphospholipid syndrome in patients with systemic lupus erythematosus at the University Hospital of Puerto Rico]. / La prevalencia del síndrome de antifosfolípidos en pacientes con lupus eritematoso sistémico en el Hospital Universitario de Puerto Rico.

This is a retrospective study based on a population of 80 patients with connective tissue diseases from the University Hospital of Puerto Rico. Among the population, 62 (77.5%) of the patients had Systemic Lupus Erythematosus (SLE), whom we were most interested to monitor. The investigation revealed an incidence of 13.8% of anthiophospholipid syndrone within the general population. Among the patients with SLE it was 12.9%, and only 5.5% among the population with other diagnoses. The antibody found with the highest frequency within the systemic lupus erythematosus population was the anticardiolipin IgG (30.6%) and lupus anticoagulant (17.7%). The antibody frequency among patients with other diagnoses was only 5.5% for lupus anticoagulant and 5.5% for anticardiolipin IgM (the only one found). Among SLE's clinical manifestations, the most frequently found were thrombocitopenia and pregnancy complications.

Partial intercalation with DNA of peptides containing two aromatic amino acids.

The interactions with DNA of tetrapeptide amides containing lysine at the N-terminal position and aromatic amino acids at the second and fourth positions (Ala at position three), 1-6, have been investigated by nmr, CD, and viscometric methods. Tetrapeptides with N-terminal lysine and a single aromatic amino acid, 7-10, were investigated as controls. Significant decreases in DNA viscosity occurred on addition of 7, with the aromatic group at the second position, but not with any of the other single aromatic amino acid peptides. All of the tetrapeptides with two aromatic groups caused DNA viscosity decreases which were two to three times larger than with 7. Peptides with p-nitrophenylalanine (p-NO2Phe) as the aromatic group were synthesized for nmr studies because of its simpler aromatic nmr spectrum relative to Phe. Large upfield shifts of the aromatic proton signals were obtained when the amino acid in the second position was L-p-NO2Phe, and the fourth position contained either p-NO2Phe or Phe. Such peptides also caused the largest DNA viscosity decreases on complex formation. Smaller upfield shifts of the aromatic signals were obtained when the amino acid in the second position was L-Phe or a D isomer of Phe or p-NO2Phe. With all peptides, larger upfield nmr shifts were obtained with heat-denatured, recooled DNA than with native DNA under the same conditions. As with nmr, CD results are quite different for the peptides with L and D amino acids at the second position. All of the results can be interpreted in terms of a model in which lysine interacts stereospecifically with the backbone in a DNA double helix and the aromatic group at the second position stacks strongly with the base pairs when the amino acid is an L isomer. The aromatic group at the fourth position can also interact with the base pairs, but primarily through a sideways stacking of the aromatic group with base pairs for either L or D isomers. Because of covalent constraints on the separation distance for the two aromatic groups in the tetrapeptides, they must stack on opposite sides of the same base pair in violation of the neighbor exclusion principle observed with classical intercalators. This stacking at the same base pair no doubt accounts for the larger viscosity decreases in DNA with the peptides containing two aromatic groups relative to those with a single aromatic group.(ABSTRACT TRUNCATED AT 400 WORDS)

Producción de gomas xánticas / Production of xanthan gums

En el período que va desde febrero has agosto de 1990, se realizó un relevamiento de Xanthomonas campestris en la zona de Luján, provincia de Buenos Aires, de 70 muestras de vegetales infectados. Se comprobó si las 50 cepas de Xanthomonas campestris obtenidas presentaban la capacidad de producir goma xantan, así como el porcentaje de conversión de sustrato en goma y el recuento de Xanthomonas campestris viables/ml de cultivo. Los mayores números de cepas productoras del polisacárido extracelular se obtuvieron de alfalfa. Asimismo, la Xanthomonas campestris pv. alfalfae presentó elevados números de células viables y porcentajes de conversión de glucosa en goma xántica

Producción de gomas xánticas / Production of xanthan gums

En el período que va desde febrero has agosto de 1990, se realizó un relevamiento de Xanthomonas campestris en la zona de Luján, provincia de Buenos Aires, de 70 muestras de vegetales infectados. Se comprobó si las 50 cepas de Xanthomonas campestris obtenidas presentaban la capacidad de producir goma xantan, así como el porcentaje de conversión de sustrato en goma y el recuento de Xanthomonas campestris viables/ml de cultivo. Los mayores números de cepas productoras del polisacárido extracelular se obtuvieron de alfalfa. Asimismo, la Xanthomonas campestris pv. alfalfae presentó elevados números de células viables y porcentajes de conversión de glucosa en goma xántica (AU)

[Production of xanthan gums]. / Producción de gomas xánticas.

Xanthomonas campestris was investigated in 70 samples of infected plants in the neighbourhood of Luján, province of Buenos Aires, between February and August, 1990. The production of xanthan gum was determined from 50 strains of Xanthomonas campestris, as well as the conversion efficiency of substrate concentration into gum and the number of colony forming units (CFU) of Xanthomonas campestris/ml of broth culture. The highest number of strains producing extracellular polysaccharide was obtained from alfalfa. Xanthomonas campestris pv. alfalfa gave elevated cell concentration and conversion efficiency of glucose in xanthan gum.

Producción de gomas xánticas. / [Production of xanthan gums]

Xanthomonas campestris was investigated in 70 samples of infected plants in the neighbourhood of Luján, province of Buenos Aires, between February and August, 1990. The production of xanthan gum was determined from 50 strains of Xanthomonas campestris, as well as the conversion efficiency of substrate concentration into gum and the number of colony forming units (CFU) of Xanthomonas campestris/ml of broth culture. The highest number of strains producing extracellular polysaccharide was obtained from alfalfa. Xanthomonas campestris pv. alfalfa gave elevated cell concentration and conversion efficiency of glucose in xanthan gum.

Structural and functional analysis of temperature-sensitive mutants of the phage phi 29 DNA polymerase.

The cloning and complete sequencing of gene 2 from four independently isolated temperature-sensitive mutants in the phage phi 29 DNA polymerase (ts2 mutants) is reported. The results obtained indicate that, in vivo, the mutations only affect the initial steps of the replication process. Interestingly, three of these mutations consist in the single amino acid change Ala to Val at position 492 of the protein. The ts2(24) and ts2(98) mutant phi 29 DNA polymerases were expressed, purified and their thermosensitivity was studied at two different steps of DNA replication: 1) protein-primed initiation and 2) elongation of the DNA chain. Whereas the ts2(24) mutation gave rise to a temperature-sensitive phenotype in both reactions, the ts2(98) mutant protein was rather insensitive to the temperature increase. In addition, the ts2(98) mutant protein showed clear differences in the activation by divalent cations. The relationship of these results with structural and functional domains in the phi 29 DNA polymerase are discussed.

Protein-primed replication of bacteriophage phi 29 DNA.

The replication of phi 29 DNA-protein p3 represents a simple model system to study the protein-priming mechanism of initiation of replication. The phi 29 DNA polymerase involved both in the initiation and elongation steps of phi 29 DNA-protein p3 replication, is a very processive enzyme and it is able to produce strand-displacement in the absence of other proteins. To correlate functional and structural domains in the phi 29 DNA polymerase point mutants in the most carboxyl region of amino-acid homology with other DNA polymerases have been constructed. Most of the mutations had a decreased initiation and elongation activity, but normal 3'----5' exonuclease activity, suggesting that this region contributes to the active domain for initiation and elongation. Point and deletion mutants in the terminal protein have allowed the mapping of one DNA-binding region and two DNA-polymerase-binding regions. The viral protein p6, which stimulates the initiation of replication, binds to a set of specific signals present at both phi 29 DNA ends. A good correlation of binding and stimulation of replication has been obtained by using fragments containing phi 29 DNA-terminal sequences and deletion mutants of protein p6. The viral protein p5 has been shown to bind to single-stranded DNA, to protect the latter against nuclease digetion, and to stimulate phi 29 DNA-protein p3 replication in vitro.