The indirect pathogenicity of Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia has at least two inducible beta-lactamases, L1 and L2, which can hydrolyze almost all classes of beta-lactam antimicrobial agents. This study was done to verify the indirect pathogenicity of S. maltophilia that could promote the growth of other beta-lactam agent-susceptible bacteria in a mixed culture. We counted CFU of beta-lactam agent-susceptible bacteria under the presence of imipenem or ceftazidime in a pure culture and mixed culture with S. maltophilia. Our results showed that beta-lactamase leaking from S. maltophilia can encourage the growth of Serratia marcescens and Pseudomonas aeruginosa even if imipenem or ceftazidime was supplemented. This study discovered a blind spot in chemotherapy against an indirect pathogen such as S. maltophilia.

Diagnostic evaluation of 2', 5'-oligoadenylate synthetase activities and antibodies against Epstein-Barr virus and Coxiella burnetii in patients with chronic fatigue syndrome in Japan.

To investigate the association of viral infections with chronic fatigue syndrome (CFS), we assayed 2', 5'-oligoadenylate synthetase (2-5AS) activities in peripheral blood mononuclear cells from CFS patients in Japan. These patients were diagnosed in two hospitals, H1 and H2, located in different areas of the country. The activities were detected in 19 (86%) and 7 (32%) of each of the 22 patients in H1 and H2, respectively, while they were detected in only four (11%) out of the 38 healthy controls. IFN-alpha was similarly detected in a few CFS patients and healthy controls. We also assayed the antibody titers against Epstein-Barr virus (EBV) and Coxiella burnetii in these patients. The EBV anti-EA-IgG antibodies were detected in two (9%) and seven (32%) of each of the 22 patients in H1 and H2, respectively. Anti-C. burnetii IgG antibodies were detected in six (27%) out of 22 patients in H1 but not in 22 patients in H2, while they were detected in one (11%) of the nine healthy controls. Some CFS patients may be associated with EBV or C. burnetii infection. There were some statistical correlations between the 2-5AS activities and antibody titers of EA-IgG (P < 0.05, Student's t-test) but not to the antibody titers of C. burnetii. The up-regulation of 2-5AS activities suggests immunological dysfunctions with some virus infections in the CFS patients. Our results indicate that 2-5AS activities are useful for a diagnostic marker of CFS and for exploring the complicated pathogenesis of CFS.

First Streptococcus agalactiae isolates highly resistant to quinolones, with point mutations in gyrA and parC.

Three isolates of Streptococcus agalactiae highly resistant to multiple fluoroquinolones were isolated in Japan. Compared with susceptible strains of S. agalactiae, these quinolone-resistant strains had double point mutations within the quinolone resistance-determining regions of gyrA and parC; Ser-81 was changed to Leu (TCA --> TTA) in the amino acid sequence deduced from gyrA, and Ser-79 was changed to Phe (TCC --> TTC) in the amino acid sequence deduced from parC. Comparative sequence analysis revealed the possibility of gene transfer between S. agalactiae and another beta-hemolytic streptococcus, Streptococcus difficile.

A polymorphism in the serotonin transporter gene regulatory region and frequency of migraine attacks.

BACKGROUND: The serotonergic system has been thought to play an important part in the pathophysiology of migraine. OBJECTIVE: To study an association between the polymorphism of serotonin (5-hydroxytryptamine [5-HT]) transporter gene-linked polymorphic region (5-HTTLPR) and migraine. Method.-We compared 151 patients with migraine with 190 healthy unrelated control subjects. The 5-HTTLPR polymorphism was detected using polymerase chain reaction. Migraine patients were interviewed regarding attack frequency in the last 6 months. RESULTS: We denoted the products of the 484-base pair (bp) fragments as the short (s) and those of 528 bp as the long (l) allele according to the previously reported manner. Migraine patients with s/s genotype were compared with those with l/s and l/l genotype. We did not find significant differences in the genotype and allele frequencies of 5-HTTLPR between patients with migraine and control subjects. Among patients with migraine, those with s/s type had significantly more frequent attacks than those with the l/s or l/l type. CONCLUSIONS: This polymorphism does not appear to be involved in a genetic predisposition to the disease but may affect the frequency of attacks in patients with migraine. These findings may contribute to our understanding of factors that influence the clinical severity of migraine.

Troglitazone improves cardiac function in patients with congestive heart failure.

Troglitazone increased cardiac output and stroke volume, as a result of decreased peripheral resistance, in diabetic patients with normal cardiac function. The cardiovascular effects of troglitazone in patients with heart failure are unknown. The aim of the study was to evaluate the cardiovascular effects of troglitazone in patients with heart failure. Blood pressure and echocardiographic findings were evaluated before and 1, 2, 3 and 4 hours after a single dose of troglitazone (400 mg) or placebo, in eight type II diabetic patients with congestive heart failure. The plasma catecholamines and coefficient of variance of RR intervals (CVRR) were also measured. Neither heart rate nor blood pressure changed after the administration of troglitazone. Left ventricular (LV) end-diastolic dimension did not change either, however, the LV end-systolic dimension significantly decreased compared with its baseline value and with that of the placebo group. On the other hand, the % fractional shortening and the E/A ratio increased significantly after troglitazone. The LV end-diastolic volume did not change, whereas the LV end-systolic volume significantly decreased. The stroke volume and the LV ejection fraction significantly increased compared with its baseline value and with that of the placebo group. The peripheral vascular resistance did not change after the administration of troglitazone, whereas plasma catecholamines significantly decreased, and CVRR remained unchanged in both groups. These hemodynamic changes suggest that a single oral dose of troglitazone induced inotropy without activation of the sympathetic nervous system.