Antimicrobial drug susceptibility of Staphylococcus aureus strains isolated from bovine and ovine mammary glands.

The activity of selected antimicrobial agents against Staphylococcus aureus was determined with the agar disk diffusion test to determine the diameter of the zone of inhibition and the E-test for determination of the minimal inhibitory concentration (MIC). The 92 S. aureus strains used in this study were isolated from bovine (n = 76) and ovine (n = 16) intramammary infections. Four antibiotics, which are frequently used in mastitis therapy were chosen: penicillin-G, ampicillin, kanamycin, and cephalexine. The fifth compound (oxacillin) was used to detect methicillin-resistant S. aureus, but no such strains could be found. According to the evaluation criteria, 65.2 (penicillin) to 93.5% (kanamycin, cephalexine) S. aureus strains were susceptible to the antibiotics tested. Ovine S. aureus strains reveal a lower resistance rate than bovine isolates. Comparison of the results of the two methods of susceptibility testing shows, with exception of penicillin and ampicillin, satisfactory agreement. Analyzing the results of the MIC endpoints and the zone diameter values, very major errors, according to the error rate bounded method of Metzler and DeHaan, occurred at an error rate of 3.3% for penicillin and 3.8% for ampicillin.

Autonomic nervous system dysfunction in sclerodermic and primary Raynaud's phenomenon.

Our aim was to investigate the sympathetic hyperactivity of systemic sclerosis that may lead to greater morbidity and mortality from cardiovascular events. We analysed the sympathetic (low-frequency) and vagal (high-frequency) components of heart rate variability, in supine and upright positions, in 10 patients with systemic sclerosis, 12 patients with primary Raynaud's phenomenon and 14 controls. We also analysed lung function in order to evaluate a possible link between heart rate variability and ventilation parameters. Heart rate variability was reduced in the supine position in subjects with systemic sclerosis both in comparison with primary Raynaud's phenomenon (total power: 1103+/-156 versus 3302+/-486 ms2, P<0.004) and control subjects (3148+/-422 ms2, P<0.002). Low-frequency power was higher in patients with systemic sclerosis than in the controls (54.5+/-4.5 versus 42.5+/-3.5 normalized units, P<0.01). During tilt, the change in heart rate was +44% in controls, +24% in subjects with primary Raynaud's phenomenon, and only +17% in the patients with systemic sclerosis (P<0.01 versus controls). In patients with systemic sclerosis we found a significant correlation between high-frequency power and the indices of lung function (residual volume: r2=0.5143, P<0.01; total lung capacity: r2=0.5142, P<0.01, vital capacity: r2=0.3789, P<0.05). Heart rate variability was reduced and sympathetic output increased in patients with systemic sclerosis. Subjects with primary Raynaud's phenomenon were characterized by normal heart rate variability and by some degree of sympathetic hyperactivity. During tilting, subjects with systemic sclerosis maintained an unmodified heart rate variability, thus suggesting an impaired baroceptor modulation of the autonomic control. The negative correlation between high-frequency power and indices of respiratory insufficiency in patients with systemic sclerosis suggests that the pulmonary structure plays an important role in the modulation of heart rate variability.

Analysis of the T cell receptor repertoire in rheumatoid arthritis.

OBJECTIVE: To evaluate whether there is a restricted T cell receptor repertoire in rheumatoid synovium and to analyse the CDR3 region of the V beta families found to be more expressed in the synovial membrane than in the peripheral blood, in order to ascertain the presence of clonotypic expansion of T lymphocytes. METHODS: The level of expression of individual V beta and V alpha families of the TCR was evaluated in paired synovial membrane and peripheral blood T cells from 8 female patients affected by rheumatoid arthritis, using the RT-PCR method. Nucleotide sequences of the CDR3 region of some V beta families were analysed in order to identify the presence of conserved sequences. Sequencing was carried out with the dideoxy chain termination method using modified T7 DNA polymerase. RESULTS: All of the V alpha and V beta families were amplified in both compartments of the 8 patients. Four patients did not show any preferential expression of the TCR alpha or beta chains in synovium compared with peripheral blood. The other 4 patients showed increased expression of one or more V alpha and/or V beta families in the synovium. We did not find any correlation between the duration of disease, rheumatoid factor status, HLA-DR type and the V gene families which were elevated in the synovium. Analysis of the CDR3 region showed the presence of conserved amino acid sequences in the synovium, but not in the peripheral blood. CONCLUSION: The V families found to be increased in 4 of the 8 patients studied were different, except for V beta 1 which was more highly expressed in 2 patients. The presence of conserved amino acid sequences in the CDR3 region is consistent with an antigen-driven T cell expansion at the site of autoimmune inflammation. These findings do not support our original hypothesis of the possible usefulness of therapy based on the inactivation or elimination of presumed pathogenic T cells using TCR-derived peptides or monoclonal antibodies against particular TCRs.

Effects of five-day versus one-day infusion of iloprost on the peripheral microcirculation in patients with systemic sclerosis.

OBJECTIVE: To evaluate the effects of iloprost infusion on the microcirculation in patients suffering from severe Raynaud's phenomenon secondary to systemic sclerosis. METHODS: Eight patients received a 7-hour infusion of iloprost for five consecutive days and then for one day 3 months later. The effects on vascular distensibility were evaluated by piezoelectric plethysmography before and after the treatment and at 2, 4 and 6 weeks. RESULTS: The beneficial effects on the peripheral microcirculation were statistically significant after five days of infusion (distensibility index: 0.18 +/- 0.01 vs 0.23 +/- 0.01, p < 0.002) and lasted for less than four weeks, whereas no difference (0.22 +/- 0.04 vs 0.24 +/- 0.02, p: ns) was seen after one day of treatment. One patient suffered from typical angina pectoris with electrocardiographic changes of the ST wave detected during the infusion. CONCLUSION: Our results show that a five-day infusion of iloprost has an effect which lasts from two to four weeks; after four weeks the distensibility index returned to the baseline value. The one-day infusion had no effect on the vascular bed, studied by the piezoelectric pletysmographic method. Treatment with five consecutive days of infusion every four weeks is an impracticable scheme to adopt, however. We have therefore instituted a treatment schedule of a single daily infusion every four weeks with the aim of maintaining the effects induced by the initial five-day infusion. The preliminary results obtained with this schedule are reported.

Oral itraconazole plus nasal amphotericin B for prophylaxis of invasive aspergillosis in patients with hematological malignancies.

The use of oral itraconazole (200 mg daily) plus nasal amphotericin B (10 mg daily) for prophylaxis of invasive aspergillosis was evaluated in 164 patients with hematological malignancies at risk due to presence of neutropenia and/or steroid therapy. This prophylactic regimen was evaluated for a period of two years. Two hundred and ninety patients with similar characteristics who were observed over the three-year period prior to the introduction of prophylaxis served as historical control group. Environmental surveillance during the study period showed constant contamination of the air with Aspergillus. Prophylaxis significantly reduced the incidence of proven invasive aspergillosis from 12/290 to 0/164 (p = 0.004), and reduced the mortality rate from 8/290 to 0/164. The incidence of proven plus probable aspergillosis amounted to 34/290 in the control group and 8/164 in the study group (p = 0.01); the mortality rates were 11/290 (3.7%) and 2/164 (1.2%) respectively. All nasal cultures in the study group were negative for Aspergillus. The prophylactic regimen was well tolerated. Larger studies assessing each agent alone and in combination are necessary to confirm these observations.