RESUMEN
The influence of subinhibitory concentrations (1/2, 1/4, 1/8, 1/16 and 1/32 MIC) of amikacin and ciprofloxacin on the morphology and adherence of uropathogenic strains was studied. Intensity of morphological changes was proportional to the concentrations of these antibiotics. Morphological changes were the most prominent after bacterial exposure to sub-MICs of ciprofloxacin. These concentrations, especially 1/2 MIC of ciprofloxacin, induced the formation of filaments of E. coli, K. pneumoniae, K. oxytoca, E. cloacae and A. calcoaceticus biotype anitratus. No morphological changes were observed in P. aeruginosa, S. epidermidis and S. aureus cells after exposure to subinhibitory concentrations of both antibiotics. Sub-MICs of amikacin affected the changes in cell shape only slightly. The exposure of bacterial strains to 1/2 MIC of ciprofloxacin induced increased vacuolation of the cells. We observed shrinkage of the protoplasm and the pleated cell walls in comparison with control cells. The greatest loss of adherence ability occurred at 1/2 MIC of ciprofloxacin after a 1-d incubation.
Asunto(s)
Amicacina/farmacología , Antiinfecciosos/farmacología , Ciprofloxacina/farmacología , Infecciones por Enterobacteriaceae/microbiología , Enterobacteriaceae/efectos de los fármacos , Infecciones Urinarias/microbiología , Adhesión Bacteriana/efectos de los fármacos , Enterobacteriaceae/crecimiento & desarrollo , Enterobacteriaceae/ultraestructura , Infecciones por Enterobacteriaceae/orina , Células Epiteliales , Femenino , Humanos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Microscopía de Contraste de Fase , Infecciones Urinarias/orinaRESUMEN
Ten E. coli K1 strains isolated from the urine of children with urinary tract infections were sensitive to the bactericidal action of normal human serum (NHS). The role of the particular mechanisms of complement activation was determined in the process of killing these strains, showing variable sensitivity to the bactericidal action of NHS; three mechanisms of activation of human complement were observed. Important role of alternative pathway activation in the bactericidal action of NHS against E. coli K1 strains independent of the classical and lectin pathways was not established.
Asunto(s)
Antígenos Bacterianos/inmunología , Antígenos de Superficie/inmunología , Activación de Complemento , Escherichia coli/inmunología , Actividad Bactericida de la Sangre , Niño , Vía Alternativa del Complemento , Vía Clásica del Complemento , Lectina de Unión a Manosa de la Vía del Complemento/inmunología , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Humanos , Viabilidad Microbiana , Infecciones Urinarias/microbiologíaRESUMEN
Gene amplification is an important mechanism of increased gene expression in a number of human solid tumors. We have recently identified and cloned sequences from a novel DNA amplification unit in malignant fibrous histiocytoma. The amplified sequences are derived from chromosome 12q13-14 and encode a gene designated SAS (sarcoma amplified sequence). In the present study, a series of soft tissue sarcomas was studied to characterize further the phenomenon of SAS amplification. Seven of 22 (32%) malignant fibrous histiocytomas and three liposarcomas contained SAS amplification. Strikingly, all of the tumors with SAS amplification occurred in central sites (i.e., in the abdominal or inguinal regions) rather than in the extremities (i.e., in the arms of legs). These observations demonstrate that SAS amplification occurs with a significant frequency in mesenchymal tumors and is particularly associated with abdominal disease.
Asunto(s)
Amplificación de Genes , Histiocitoma Fibroso Benigno/genética , Sarcoma/genética , Neoplasias de los Tejidos Blandos/genética , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Amplification of 12q13-14 occurs in a subset of human sarcomas including malignant fibrous histiocytoma and liposarcoma. This chromosomal region has previously been found to include a number of growth-related genes including the GLI proto-oncogene and the p53-associated protein, MDM2. We now report the characterization of SAS (sarcoma amplified sequence), a novel transcript found in this region. Sequence analysis demonstrates that SAS is a novel member of a transmembrane protein family (transmembrane 4 superfamily or TM4SF) thought to be involved in growth-related cellular processes. This observation adds a TM4SF protein to the cluster of genes at 12q13-14 frequently amplified in human sarcomas.
Asunto(s)
Amplificación de Genes , Proteínas de la Membrana/genética , Proteínas de Neoplasias/genética , Sarcoma/genética , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Células Cultivadas , Cromosomas Humanos Par 12 , Secuencia de Consenso , Humanos , Datos de Secuencia Molecular , Proto-Oncogenes Mas , Mapeo Restrictivo , Homología de Secuencia de Aminoácido , TetraspaninasRESUMEN
OBJECTIVE: The prevalence of hypocalcaemia is known to be elevated in critically ill patients, but the expected benefit from calcium repletion in hypocalcaemic patients has not been well defined. The objective of the present study was therefore prospective determination of the cardiovascular response to calcium administration in critically ill patients with hypocalcaemia. PATIENTS: A total of 17 patients found to have ionized hypocalcaemia (Ca2+ < 1.05 mmol/l) from a group of 32 patients who were invasively monitored as part of their ICU management. INTERVENTION: Slow intravenous injection of 1 g of calcium chloride. MEASUREMENTS AND RESULTS: Calcium administration was followed by an increase in mean arterial pressure from 77 +/- 8 to 90 +/- 12 mmHg (P < 0.01). There was no significant change in cardiac filling pressures or heart rate. Cardiac index and systemic vascular resistance increased slightly but not significantly (from 2.67 +/- 0.92 to 2.81 +/- 1.25 1/min.m2 and from 2133 +/- 647 to 2378 +/- 817 dynes.s.cm-5 m-2, respectively). Left ventricular stroke work index increased from 23 +/- 8 to 32 +/- 13 g.m/m2 (P < 0.01). These changes were maintained for 60 min. CONCLUSIONS: The correction of hypocalcaemia can result in a significant increase in arterial pressure that can persist for at least 1 h. Despite an associated improvement in left ventricular function, cardiac index and oxygen delivery do not increase significantly.
Asunto(s)
Cloruro de Calcio/uso terapéutico , Hemodinámica/efectos de los fármacos , Hipocalcemia/tratamiento farmacológico , Anciano , Calcio/sangre , Enfermedad Crítica , Humanos , Hipocalcemia/sangre , Hipocalcemia/fisiopatología , Infusiones Intravenosas , Persona de Mediana Edad , Prevalencia , Estudios Prospectivos , Factores de TiempoRESUMEN
Cytogenetic analysis of liposarcomas has demonstrated that translocation (12;16) (q13.3;p11.2) is characteristic of the myxoid subtype of this adipose tissue tumor. Our previous results suggested that the GLI gene is close to the translocation breakpoint on chromosome 12. We now describe a yeast artificial chromosome (YAC) that contains GLI and spans the chromosome 12 region involved in the t(12;16) breakpoint. This clone will permit rapid definition of the genetic region surrounding the breakpoint and allow isolation of the gene presumably affected by the translocation.
Asunto(s)
Cromosomas Fúngicos , Cromosomas Humanos Par 12 , Cromosomas Humanos Par 16 , Biblioteca de Genes , Liposarcoma/genética , Translocación Genética , Clonación Molecular , Genoma Humano , HumanosRESUMEN
The role of ozone in the susceptibility of clinical isolates of Acinetobacter anitratus and Pseudomonas aeruginosa to serum was investigated. It was found that ozone-treated cells were more susceptible to complement-mediated killing serum. These results suggest that ozone damage or change of cell membrane leads to a more rapid penetration of the membrane attack complex of complement.
Asunto(s)
Actividad Bactericida de la Sangre/efectos de los fármacos , Proteínas del Sistema Complemento/inmunología , Ozono/toxicidad , Acinetobacter/inmunología , Animales , Bovinos , Humanos , Pseudomonas aeruginosa/inmunologíaRESUMEN
Most Hafnia alvei strains are sensitive to the bactericidal action of normal bovine serum (NBS) as well as to a serum in which the alternative pathway of complement activation has been thermally blocked. Introduction of polysaccharides (PS) to NBS lowers the bactericidal effect. In a serum in which the alternative pathway of complement activation is blocked, PS completely cancels the bacterial effect.
Asunto(s)
Actividad Bactericida de la Sangre , Enterobacteriaceae/inmunología , Animales , Secuencia de Carbohidratos , Bovinos , Enterobacteriaceae/efectos de los fármacos , Heces/microbiología , Datos de Secuencia Molecular , Polisacáridos Bacterianos/sangreRESUMEN
Salmonella strains resistant to normal cord serum were found to become susceptible to it when the outer membrane was damaged by colistin, adult normal serum or Tris-HCl buffer. The present results indicate that after such treatment cord sera exert bactericidal effect, despite significant deficiencies in factors playing an essential role in this process.
Asunto(s)
Sangre Fetal/inmunología , Salmonella/inmunología , Actividad Bactericida de la Sangre/efectos de los fármacos , Membrana Celular/inmunología , Colistina/farmacología , Humanos , Salmonella enteritidis/inmunología , Salmonella typhimurium/inmunologíaRESUMEN
Weaker bactericidal activity of cord sera against Salmonella bacilli was shown in comparison with maternal venous sera. No correlation was found between the bactericidal activity and the levels of complement, immunoglobulins and lysozyme in cord sera. Worthy of notice is detected in these researches specificity of bactericidal action of cord sera.
Asunto(s)
Actividad Bactericida de la Sangre , Sangre Fetal/inmunología , Salmonella/inmunología , Proteínas del Sistema Complemento/inmunología , Femenino , Humanos , Inmunoglobulina M/inmunología , Técnicas In Vitro , Recién Nacido , Intercambio Materno-Fetal , Embarazo , Salmonella enteritidis/inmunología , Salmonella typhimurium/inmunologíaRESUMEN
PURPOSE: The aim of this study was to investigate the relation between interleukin (IL) 10, tumor necrosis factor alpha (TNF alpha), IL-1, and IL-6 levels in patients with septic shock and relate these cytokine levels to the development of organ failure. PATIENTS AND METHODS: In 11 patients with septic shock of recent onset, blood was sampled for determinations of TNF, IL-1, IL-6, and IL-10. The degree of organ failure was scored for four organ systems (respiratory, hepatic, renal, hematologic) in the first 48 hours of the study. RESULTS: The APACHE II score was 21 +/- 4. Three patients died. IL-10 levels were directly correlated with TNF levels (r = 0.73, P < .05) and IL-6 levels (r = 0.67, P < .05); and inversely correlated with total C3 (r = -0.73, P < .05) and CH50 (r = -0.68, P < .05). Both IL-10 and TNF levels were correlated to the organ failure score (r = 0.75 and r = 0.68, both P < .01). Six patients with high IL-10 levels (> 60 pg/mL) had lower C3 (37 +/- 11 v 62 +/- 10 mg/dL) and CH50 (32 +/- 7 v 68 +/- 19%), and higher organ failure scores (5.7 +/- 0.8 v 3.8 +/- 1.3) than those with low IL-10 levels (all P < .05). CONCLUSION: Although IL-10 has an inhibitory effect on the production of cytokines, it is released together with TNF and IL-6 in patients with septic shock. IL-10 blood levels are directly related to the severity of inflammation and the development of organ failure in septic shock.
Asunto(s)
Citocinas/sangre , Interleucina-10/sangre , Choque Séptico/inmunología , APACHE , Adulto , Anciano , Femenino , Humanos , Interleucina-1/sangre , Interleucina-6/sangre , Masculino , Persona de Mediana Edad , Insuficiencia Multiorgánica/sangre , Insuficiencia Multiorgánica/etiología , Choque Séptico/complicaciones , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
A model of a multivalued associative memory is presented. This memory has the form of a fully connected attractor neural network composed of multistate complex-valued neurons. Such a network is able to perform the task of storing and recalling gray-scale images. It is also shown that the complex-valued fully connected neural network may be considered as a generalization of a Hopfield network containing real-valued neurons. A computational energy function is introduced and evaluated in order to prove network stability for asynchronous dynamics. Storage capacity as related to the number of accessible neuron states is also estimated.
RESUMEN
The susceptibility of Escherichia coli strains with K1 surface antigen (K1+) and rods without this antigen (K1-) to the bactericidal action of normal bovine serum and human normal cord serum was determined. Seventy E. coli strains (35 K1+ and 35 K1-) were isolated from urine obtained from children with urinary tract infections. The strains investigated showed variable sensitivity to the bactericidal action of the sera. E. coli K1+ strains were characterized by lower sensitivity to bactericidal effect of the sera in comparison with K1- rods. The role of the particular mechanisms of complement activation in the process of killing of the E. coli strains was also determined.
Asunto(s)
Antígenos Bacterianos/inmunología , Actividad Bactericida de la Sangre , Escherichia coli/inmunología , Animales , Niño , Activación de Complemento , HumanosRESUMEN
The susceptibility to the bactericidal action of normal bovine serum of twenty two Escherichia coli K1 strains, isolated from the urine of patients with urinary tract infections, was determined. Only four strains were resistant. Ozonization of bacterial suspensions enhanced the sensitivity of the strains to the action of both normal serum and a serum in which the alternative pathway of complement activation was thermally blocked.
Asunto(s)
Antígenos Bacterianos , Actividad Bactericida de la Sangre/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Ozono/farmacología , Animales , Cápsulas Bacterianas , Bovinos , Escherichia coli/inmunología , Escherichia coli/patogenicidad , Infecciones por Escherichia coli/microbiología , Humanos , Técnicas In Vitro , Polisacáridos Bacterianos/inmunología , Infecciones Urinarias/microbiologíaRESUMEN
Any convulsion during labour requires immediate action, but before this can occur a correct diagnosis must be made. Here we describe a case where a 'fit' was wrongly attributed to epidural analgesia. This was in fact a dystonic reaction secondary to undeclared self-medication with metoclopramide. It is therefore important to ensure that a full drug history is obtained from all patients to exclude a drug interaction or side-effect when faced with unusual and potentially serious complications of drug therapy.
RESUMEN
A comparison was made regarding susceptibility of strains of E. coli to bactericidal activity of normal human serum. It was found that when among strains with K1 antigen over 40% were resistant to normal human serum, strains without this antigen were resistant in only 15%. Sub-doses of cefotaxime (1/2 and 1/3 MIC) together with normal human serum strong bactericidal action against strains of K1-possessing E. coli resistant to serum. Sub-doses of cefotaxime cause occurrence of elongated form of bacteria, starting one hour after addition of the antibiotic. Elongated forms of bacteria are not loosing antigen K1 and this suggest that it probably does not exert a role in protection of bacteria against synergistic action of both studied factors.
Asunto(s)
Antígenos Bacterianos/inmunología , Sangre/inmunología , Cefotaxima/farmacología , Escherichia coli/efectos de los fármacos , Antígenos de Superficie/inmunología , Escherichia coli/inmunología , Escherichia coli/patogenicidad , Humanos , Valores de Referencia , Especificidad de la EspecieRESUMEN
Autoagregating strains of bacteria are characterised by high surface hydrophobicity, which determines their ability to adhesion. An assessment was done of non-specific adhesion to solid surfaces of S. aureus strains isolated from blood, pus and nasopharynx of hospitalised people. The method used made possible differentiation of strains, which were studied, on the basis of their surface characteristics. Their properties decide about the abilities of strains to the colonisation of host tissues and at the same time they influence their potential virulence. In the study attention was also paid to the participation of surface proteins in the processes of adhesion cells to glass surfaces.
Asunto(s)
Adhesión Bacteriana , Staphylococcus aureus/patogenicidad , Sangre/microbiología , Vidrio , Humanos , Nasofaringe/microbiología , Especificidad de la Especie , Staphylococcus aureus/clasificación , Staphylococcus aureus/metabolismo , Supuración/microbiología , Propiedades de Superficie , Virulencia/fisiologíaRESUMEN
Hydrophobic properties are considered as a factor enhancing the adhesion of bacteria to tissue cells. The strains of P. aeruginosa isolated from patients with urinary tract infections (UTI), from feces and soil were investigated. It shows that over 50% strains isolated from UTI had hydrophobic cell surface. Most of all strain investigated (67.9%) is characterized by hydrophobicity what probably favours their pathogenicity.
Asunto(s)
Pseudomonas aeruginosa/clasificación , Heces/microbiología , Humanos , Pseudomonas aeruginosa/aislamiento & purificación , Pseudomonas aeruginosa/patogenicidad , Microbiología del Suelo , Especificidad de la Especie , Propiedades de Superficie , Orina/microbiologíaRESUMEN
The nature of bacterial isolates from children with clinically suspected urinary tract infections (UTI) was studied. The susceptibility of urinary pathogens to selected antibiotics was determined. The results clearly show that E. coli was identified as the main causative agent of UTI children (67% of isolates). The second commonest pathogen was P. mirabilis (10%). Over half E. coli isolates were resistant to amino-penicilins but almost all isolates (over 80%) were sensitive to antimicrobial agents combined with beta-lactamase inhibitors. We found significantly high percentage (32.5%) of ESBL strains among K. pneumoniae isolates.