Influence of subinhibitory concentrations of amikacin and ciprofloxacin on morphology and adherence ability of uropathogenic strains.

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.

The mechanisms of activation of normal human serum complement by Escherichia coli strains with K1 surface antigen.

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.

SAS amplification in soft tissue sarcomas.

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.

SAS, a gene amplified in human sarcomas, encodes a new member of the transmembrane 4 superfamily of proteins.

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.

Correction of hypocalcaemia in the critically ill: what is the haemodynamic benefit?

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.

Isolation of a yeast artificial chromosome clone that spans the (12;16) translocation breakpoint characteristic of myxoid liposarcoma.

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.

Studies on the influence of ozone on complement-mediated killing of bacteria.

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.

The sensitivity of Hafnia alvei strains to the bactericidal effect of serum.

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.

Increase in the susceptibility of Salmonella strains to bactericidal activity of cord serum following treatment with agents disturbing surface structures.

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.

Impaired bactericidal activity of cord sera against Salmonella strains.

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.

Blood interleukin 10 levels parallel the severity of septic shock.

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.

Complex-valued multistate neural associative memory.

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.

The sensitivity of escherichia coli strains with K1 surface antigen and rods without this antigen to the bactericidal effect of serum.

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.

Influence of ozone on the susceptibility of Escherichia coli K1 to the bactericidal action of serum.

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.

Acute dystonia in labour: side-effect of concealed self-medication attributed to epidural analgesia.

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.

[Interaction of cefotaxime and normal human serum in the bacteriocidal process against strains of Escherichia coli producing surface K1 antigen]. / Wspóldzialanie cefotaksymu i normalnej surowicy ludzkiej w procesie bakteriobójczym wobec paleczek Escherichia coli wytwarzajacych powierzchniowy antygen K1.

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.

[Nonspecific adhesion of Staphylococcus aureus strains to solid surfaces]. / Niespecyficzna przyczepnosc komórek Staphylococcus aureus do powierzchni stalych.

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.

[Hydrophobic properties of Pseudomonas aeruginosa strains]. / Hydrofobowe wlasciwosci szczepów Pseudomonas aeruginosa.

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.

[Infectivity and resistance to antibiotics of uropathogenic gram-negative rods]. / Wystepowanie i wrazliwosc na leki uropatogennych paleczek Gram-ujemnych.

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.