Action of fluoroquinolones and Linezolid on logarithmic- and stationary-phase culture of Mycobacterium tuberculosis

BACKGROUND

The new challenges involved in the chemotherapy of tuberculosis make it necessary to find novel drugs, especially ones that are useful in the latent phase of the disease.

METHODS

We evaluated the activity of linezolid and fluoroquinolones against logarithmic- and stationary-phase Mycobacterium tuberculosis.

RESULTS

We observed that linezolid exhibits antibacterial action, although slowly, in both situations. Quinolones with an 8-methoxy group exhibit greater activity than levofloxacin in logarithmic growth phases, whereas levofloxacin exhibits greater activity in stationary-phase growth.

CONCLUSION

The study of the activity of drugs against the M. tuberculosis microorganism in the latent phase is one of the most important tools available in the fight against the tuberculosis epidemic, and both linezolid and the new fluoroquinolones appear to be promising drugs.

Dual blockade of EGFR and ERK1/2 phosphorylation potentiates growth inhibition of breast cancer cells

One of the major targets for breast cancer therapy is the epidermal growth factor receptor (EGFR) and related receptors, which signal via different signal transduction pathways including the mitogen-activated protein kinase (MAPK) pathway. This study determined whether there is a correlation between EGFR/HER2 status and MAPK (ERK1/2) phosphorylation in breast cancer cells, and how this affects the response to an inhibitor of the receptors. Expression of EGFR, HER2 and phosphorylated ERK1/2 were measured by immunoblotting in a panel of breast cancer cell lines. Several lines expressed high levels of pERK1/2, with no obvious correlation with the level of EGFR/HER2. The EGFR tyrosine kinase inhibitor PKI166 inhibited growth and induced apoptosis in some cells with high levels of growth factor receptors (MDA-MB-468, SUM149, SKBR3), but was less effective in cells that also had high basal ERK1/2 activity (MDA-MB-231). The combination of an inhibitor of MAPK signalling (U0126) and PKI166 produced significantly more inhibition and apoptosis than either agent alone. This suggests that constitutive activation of the MAPK pathway may bypass inhibition of EGFR/HER2 tyrosine kinases, and lead to insensitivity to agents targeting the receptors. However, inhibiting both EGFR/HER2 and MAPK signalling can result in significant growth inhibition and apoptosis of EGFR-expressing breast cancer cells.

[Development of a questionnaire for the assessment and quantification of overweight and obesity related lifestyles]

INTRODUCTION

Lifestyle intervention is mandatory for obesity treatment. The aim of this study is to design a questionnaire to describe and quantify those behaviours more closely related to obesity in the Spanish obese population.

METHODS AND PROCEDURES

An expert panel designed a preliminary 57 Liker-type item questionnaire, which was self-administered to 335 overweight patients (110 male, 225 female; age, 42 +/- 14 years; BMI, 32.6 +/- 3.7 kg/m2). After a subjacent dimensionality searching and item reducing first phase, a shrunk questionnaire of 24 items was then self-administered to 156 overweight patients (52 male, 104 female; age 42 +/- 12 years; BMI, 33.1 +/- 3.5 kg/m2); 56 of those patients were re-administered the questionnaire in order to provide test-retest information.

RESULTS

Final questionnaire includes 22 items clustered in five dimensions: diet caloric intake, searching for psychological well-being eating, physical activity, healthy eating and alcohol intake. Proposed factorial structure is mostly reproduced in different samples and using different extraction methods: all dimensions but alcohol intake score alpha values > 0.75 for liability; test-retest stability is greater than 0.90 in all dimensions but alcohol intake; results for all validity tests performed (of construct, of content and discriminative) are highly satisfactory.

CONCLUSION

Metrics study results (liability and validity) demonstrate that the proposed questionnaire provides an excellent tool to assess those lifestyles related to obesity control.

Effect of clinical and socio-economic factors on the rate of clustering of Mycobacterium tuberculosis clinical isolates in Elche (Spain)

We studied the association that exists between the epidemiological type clustering of isolates of Mycobacterium tuberculosis and certain clinical, epidemiological and socio-economic characteristics of tuberculosis patients in the Elche health district of Spain. A total of 144 patients diagnosed between 1993 and 1999 and whose isolates had been genotyped by IS6110-RFLP in an earlier study were included. Multivariate analysis showed that the independent variables associated with clustering of strain types were: age (1-25 years, OR 2.92, 95% CI 0.83 10.3), a high percentage of infection in the first circle of contacts (OR 2.89, 95% CI 0.96-8.68), urban dwelling (OR 2.12. 95% CI 0.73-6.2), use of bronchoscopy to obtain samples (OR 16.3, 95% CI 2.3-11.5) and working contact with many people (OR 2.81, 95% CI 0.94-8.3). These data contribute to a better understanding of the epidemiology of tuberculosis and improved systems of control.

Mutant prevention concentration: comparison of fluoroquinolones and linezolid with Mycobacterium tuberculosis

OBJECTIVES

The mutant prevention concentration (MPC) has recently been defined to characterize the capacity for severely restricting the selection of resistant mutants during antibiotic treatment. We determined this parameter for ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin and linezolid in Mycobacterium tuberculosis clinical isolates in our setting.

METHODS

We determined the antibiotic concentration that prevents the selection of resistant mutants following inoculation with a high mycobacteria inoculum on Middlebrook 7H11 plates with serial dilutions of the antibiotics in 224 M. tuberculosis isolates.

RESULTS

Fifty percent of the strains exhibited values of MPC (MPC(50)) lower than 0.8, 0.6, 0.4, 0.4 and 0.6 mg/L for ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin and linezolid, respectively. If 90% of the strains are considered (MPC(90)), the values are seen to rise to 2, 1.8, 1, 1.2 and 1.2 mg/L, respectively.

CONCLUSIONS

When we compare this parameter with the drug levels in serum and tissue, it can be seen that ciprofloxacin is the least useful of the fluoroquinolones studied, whereas moxifloxacin appears to be the most active. Linezolid exhibits excellent activity against this microorganism (MPC(90) 1.2 mg/L and AUC 140.3 mg.h/L) and this makes us consider that its usefulness in the treatment of this pathology should be thoroughly evaluated.

Sedación en la endoscopia digestiva. Resultados de una encuesta hospitalaria en Cataluña

INTRODUCTION

The need for sedation is increasing in digestive endoscopy units (DEU). There are no data on the use of sedation in DEU in Catalonia (Spain).

OBJECTIVE

To evaluate the use of sedation in DEU in Catalonia.

MATERIAL AND METHOD

A questionnaire on the practice of sedation was designed and sent to the heads of medical and nursing staff of the DEU of 63 public and private hospitals in Catalonia. Two mailings were sent with an interval of three months between each. The questionnaire included 62 items on the characteristics of the hospital and the DEU, number of explorations, frequency of sedation use, drugs employed, participation of an anesthesiologist, use of monitoring, and complications.

RESULTS

Forty-four DEU (70%) corresponding to 31 public hospitals and 13 private hospitals completed the questionnaire. Evaluation of sedation patterns was based on 105,904 explorations performed in the various DEU (56,453 gastroscopies, 47,278 colonoscopies and 2,173 endoscopic retrograde cholangiopancreatographies (ERCP) in 2001. Sedation, sedation-analgesia or anesthesia was used in 17% of gastroscopies, 61% of colonoscopies and 100% of ERCP. Sedation was administered by an anesthesiologist in 7% of gastroscopies, 25% of colonoscopies and 38% of ERCP. Anesthesiologist administration was more frequent in private than in public centers (gastroscopies: 25% vs. 2%; colonoscopies: 57% vs. 9%, p < 0.001). No deaths associated with the use of sedation were reported. Eighty-nine percent of the DEU complied with standard recommendations for the practice of sedation.

CONCLUSIONS

In Catalonia, the use of sedation is highly variable, depending on the endoscopic procedure and the DEU. Use of sedation in infrequent in gastroscopy, fairly widespread in colonoscopy and routine in ERCP. Anesthesiologist administration is significantly more frequent in private hospitals. Most DEU follow standard sedation practices.

Usefulness of different techniques in the study of the epidemiology of salmonellosis

Our objective was to evaluate the usefulness of serotyping, phagotyping, antibiotyping and RAPD (random amplified polymorphic DNA) in the study of the epidemiology of salmonellosis in Elche (Spain). We examined 1232 clinical isolates of non-typhoid Salmonella serotypes. Serotyping adequately differentiates 12.3% of the isolates and phagotyping raises this percentage to 37%. Antibiotyping is a suitable complement in certain circumstances, such as in the case of specific outbreaks. RAPD is a fast and simple technique which is within the reach of most laboratories, complementing the results obtained by antibiotyping and serotyping, in order to be able to control outbreaks of salmonellosis in everyday practice.

Characterisation of Salmonella spp. mutants produced by exposure to various fluoroquinolones

We repeatedly exposed six Salmonella spp. strains of different serotypes (three susceptible to nalidixic acid and three resistant) to constant low concentrations of various fluoroquinolones with the aim of characterising the mutations that produce the first decrease in susceptibility to these agents. The fluoroquinolone-susceptibility of all the strains was reduced after repeated exposure to these agents. However, gyrA mutants were not always produced. Furthermore, the type of mutation produced and the time taken for it to appear varied depending on the initial resistance to nalidixic acid, the antibiotic used and the serotype involved. Therefore, we believe that the initial decrease in quinolone-susceptibility is due to various mechanisms and, in many cases, is not caused by mutations in the gyrA gene

Prevalence of antibodies to Borrelia burgdorferi sensu lato in southern chamois (Rupicapra pyrenaica) in Spain

Ungulates are involved in the epidemiology of Borreliosis as maintenance hosts for vector tick species. We evaluated the prevalence of antibodies to Borrelia burgdorferi sensu lato in two different populations of southern chamois in Spain. Forty-six sera (40.4%) were positive at titres >/=1 : 64 using an indirect immunofluorescence assay (IFAT).

In vitro activity of new fluoroquinolones and linezolid against non-tuberculous mycobacteria

The objective of the study was to determine the activity of new fluoroquinolones and linezolid against 108 clinical isolates of different species of non-tuberculous mycobacteria isolated in Spain. Gatifloxacin and moxifloxacin were found to be more effective than levofloxacin. Mycobacterium kansasii was more susceptible to the fluoroquinolones tested than M. avium complex and M. fortuitum was more susceptible than M. chelonae. Linezolid was more active against M. kansasii than against M. avium complex. A better understanding of the relationship between the in vitro activity of these compounds and their usefulness in the treatment of these infections is needed. The new fluoroquinolones exhibit good activity against M. kansasii and M. fortuitum and linezolid is active against M. kansasii.

Synergic activity of fluoroquinolones and linezolid against Mycobacterium tuberculosis

We evaluated the in vitro activity against Mycobacterium tuberculosis of the combination of fluoroquinolones and linezolid with classical drugs. The combination of isoniazid with fluoroquinolones had synergic activity in nine of the ten isoniazid-susceptible strains. We also found synergism between rifampicin and linezolid in five of the 15 strains susceptible to rifampicin. The clinical significance of these findings should be evaluated.

Effect of indapamide SR on microalbuminuria--the NESTOR study (Natrilix SR versus Enalapril Study in Type 2 diabetic hypertensives with micrOalbuminuRia)--rationale and protocol for the main trial

In type 2 diabetic hypertensive patients, microalbuminuria can be due to hypertension and/or diabetic nephropathy. Angiotensin-converting enzyme (ACE) inhibitors act preferentially on microalbuminuria due to diabetic nephropathy. The objective is to demonstrate the efficacy of a thiazide-like diuretic, indapamide sustained release (SR), at reducing microalbuminuria in hypertensive type 2 diabetic patients in comparison with an ACE inhibitor, enalapril. The study is an international multicentre, 12-month, randomized, double-blind, controlled, two parallel group study of type 2 diabetic patients with hypertension (140 mmHg < or = systolic blood pressure <180 mmHg and diastolic blood pressure <110 mmHg) and microalbuminuria. Intervention is after a 4-week placebo period, patients with microalbuminuria > or = 20 and < or = 200 microg/min are randomized to indapamide SR 1.5 mg or to enalapril 10 mg once a day for a one-year treatment period. An additional label treatment by amlodipine 5-10 mg (1st step) and atenolol 50-100 mg (2nd step) a day is permitted after 6 weeks of treatment based upon blood pressure response. The main outcome measures are microalbuminuria expressed as urinary albumin to creatinine ratio, albumin fractional clearance, and albumin excretion rate evaluated on overnight urine collections. Secondary criteria are supine and standing systolic, diastolic and mean blood pressure; and biological and clinical safety. This study will complete the knowledge of the efficacy of indapamide SR in hypertension and target organ damage and will provide valuable information on the management of type 2 diabetic hypertensives with microalbuminuria.

In vitro activity of moxifloxacin, levofloxacin, gatifloxacin and linezolid against Mycobacterium tuberculosis

The in vitro activity of moxifloxacin, gatifloxacin, levofloxacin and linezolid was evaluated against 234 strains of Mycobacterium tuberculosis isolated in the Southeast of Spain. All drugs tested showed good activity, with an MIC(90) of less than 1 mg/l, and were active against isociacide and rifampicin resistant strains. Three strains were resistant to isoniazid and to the fluoroquinolones, which suggested the existence of mechanisms of resistance not yet described. These new compounds may prove to be therapeutic alternatives for treatment of multi-resistant tuberculosis and further studies should be done to demonstrate their true usefulness.

[Comparability between the ninth and tenth revisions of the International Classification of Diseases applied to coding causes of death in Spain]

OBJECTIVE

To analyze comparability between the ninth and tenth revisions of the International Classification of Diseases (ICD) applied to coding causes of death in Spain.

METHODS

According to the ninth and tenth revisions of the ICD, 80,084 statistical bulletins of mortality registered in 1999 were assigned the Basic Cause of Death. The statistical bulletins corresponded to the Autonomous Communities of Andalusia, Cantabria, Murcia, Navarre and the Basque Country, and the city of Barcelona. The underlying causes of death were classified into 17 groups. Simple correspondence, the Kappa index and the comparability ratio for major causes were calculated.

RESULTS

A total of 3.6% of deaths changed group due to an increase (36.4%) in infectious and parasitic diseases, mainly because of the inclusion of AIDS, and a corresponding decrease due to the exclusion of endocrine, nutritional and metabolic disorders. Furthermore, myelodysplastic syndrome was moved to the category of neoplasm. The group including nervous system diseases, eye and related diseases, and ear and mastoid apophysis diseases increased (14.7%) at the expense of mental and behavior disorders, due to the inclusion of senile and presenile organic psychosis. Poorly-defined entities increased (14.1%) due to the inclusion of cardiac arrest and its synonyms, together with heart failure, to the detriment of diseases of the vascular system. Diseases of the respiratory system increased (4.8%) due to the inclusion of respiratory failure, previously considered as a poorly defined cause. The correspondence for all causes was 96.4% and kappa's index was 94.9%

CONCLUSIONS

The introduction of ICD-10 affects the comparability of statistical series of mortality according to cause. The results of this study allow us to identify the main modifications and to quantify the changes in the major causes of mortality in Spain.

Implications on human fertility of the 677C-->T and 1298A-->C polymorphisms of the MTHFR gene: consequences of a possible genetic selection

Mutant alleles with the 677C-->T and 1298A-->C polymorphisms of the MTHFR gene, and consequent lower methylentetrahydrofolate reductase enzyme activity, have been related to higher plasma homocysteine levels, which are associated with cardiovascular diseases. We assessed the genotype frequencies, degrees of fertility and homocysteine levels, and discuss a possible genetic selection for the gene polymorphisms studied. A total of 1777 subjects (897 women and 880 men), divided into four age groups, were genotyped by PCR and restriction fragment length polymorphism. The total homocysteine concentration in plasma was determined by fluorescence polarization immunoassay. Based on random pairs and linkage disequilibrium of the two polymorphisms, we estimated the rate of fetal non-viability according to the combinations of these two polymorphisms to be 4.63% for the group >24 years old and 6.31% for the group <24 years old. We detected an increased frequency of mutant alleles in the youngest age group, coincident with a generally increased folate intake by pregnant women in Spain. The genetic selection detected leads to an increase in mutated individuals, the number of whom could increase four-fold over the next 75 years. Although generally reduced in the younger age groups, the homocysteine plasma levels were shown to increase in individuals according to the number of mutations, especially those of the 677T allele.

Mesenteric tuberculosis with jejunal infiltration

A 69-year-old female was admitted to our hospital because of asthenia, anorexia and 20 kg weight loss. An ultrasound study and computerized tomography (CT) imaging revealed a mesenteric mass and laparotomy was performed. The diagnosis was mesenteric tuberculosis with jejunal involvement. This represents an atypical onset of tuberculosis in a non-immunosuppressed patient.