The dynamics of cardiac defense: From attention to action

The attentional and motivational significance of cardiac defense is examined in two studies. In Study 1, cardiac defense was evoked by an intense acoustic stimulus in the context of either a visual search or a memory search task using letters as stimuli. Results showed a potentiation of the long latency acceleration of cardiac defense in the visual search task. In Study 2, participants performed the same visual search task using pleasant, neutral, and unpleasant pictures as stimuli. Results showed a further potentiation of the long latency acceleration of cardiac defense when the visual search task was performed with unpleasant, compared to pleasant or neutral pictures. These results indicate that cardiac defense has both attentional and motivational contributions, where the attentional significance is related to increased sensory processing, whereas the motivational significance is associated with preparation for active defense.     

Bacterial infections in cirrhosis: epidemiological changes with invasive procedures and norfloxacin prophylaxis.

The extensive use of invasive procedures and of long-term norfloxacin prophylaxis in the management of cirrhotic patients may have influenced the epidemiology of bacterial infections in cirrhosis. We conducted a prospective evaluation of all bacterial infections diagnosed in patients with cirrhosis in a Liver Unit between April 1998 and April 2000. A total of 405 patients presented 572 bacterial infections in 507 admissions. Spontaneous bacterial peritonitis was the most frequent infection (138 cases). Gram-positive cocci were responsible for 53% of total bacterial infections in the study, being the main bacteria isolated in nosocomial infections (59%). Patients requiring treatment in an intensive care unit and those submitted to invasive procedures presented a higher rate of infections caused by gram-positive cocci (77% vs. 48%, P <.001 and 58% vs. 40%, P <.02, respectively). Fifty percent of culture-positive spontaneous bacterial peritonitis in patients on long-term norfloxacin administration (n = 93) and 16% in patients not receiving this therapy (n = 414) were caused by quinolone-resistant gram-negative bacilli, P =.01. The rate of culture-positive spontaneous bacterial peritonitis caused by trimethoprim-sulfamethoxazole-resistant gram-negative bacilli was also very high in patients on long-term norfloxacin administration (44% vs. 18%, P =.09). In conclusion, infections caused by gram-positive cocci have markedly increased in cirrhosis. This phenomenon may be related to the current high degree of instrumentation of cirrhotic patients. Quinolone-resistant spontaneous bacterial peritonitis constitutes an emergent problem in patients on long-term norfloxacin prophylaxis, with trimethoprim-sulfamethoxazole not being a valid alternative.     

Meningococcal meningitis with ‘normal’ cerebrospinal fluid

A prospective study was made of all patients with normal CSF counts and positive cultures for Neisseria meningitidis diagnosed in “El Vallés” County, Barcelona between January 1987 and December 1990. Meningococcal meningitis was documented in 82 patients, eight of whom (seven children, five boys and two girls with a mean age of 5·6 ± 3·3 years, and a 69-year-old male patient) had no apparent CSF abnormalities in the initial lumbar puncture. At the time of admission all patients had fever (mean 39·1 °C) of 10·8 ± 5·6 hour duration and petechial rash which had been present for a mean of 3·6 ± 3·3 hours. Signs of meningeal irritation were not found. A 4-month-old infant with symptoms of circulatory collapse, intracranial hypertension and impairment of consciousness subsequently died of septicemia in 48 hours. Group B N. meningitidis was isolated in six cases (reduced penicillin-susceptibility in two cases) and group C N. meningitidis in the remaining two (reduced penicillin-susceptibility in one case). Patients without pleocytosis did not differ in a statistically significant fashion from the patients with high pleocytosis in the duration of temperature, and petechial rash, leukopenia, positive blood culture and fatal outcome.     

Pancreatic toxic effects associated with co-administration of didanosine and tenofovir in HIV-infected adults

The rise in didanosine concentrations in plasma when given with tenofovir raises concern for a high risk of toxic effects. Recommendations to reduce didanosine dose have been issued, but only for adults weighing more than 60 kg. We reviewed cases of pancreatitis in patients receiving didanosine plus tenofovir, didanosine alone, and tenofovir alone to assess the incidence of and risk factors for pancreatitis. Between Aug 1, 2001, and Nov 30, 2003, five of 185 (2.7%) patients receiving didanosine plus tenofovir, one of 182 (0.5%) on didanosine without tenofovir, and none of 208 on tenofovir without didanosine developed pancreatitis (p=0.016). Co-administration of both drugs versus each of them individually was an independent risk factor for pancreatitis (crude hazard ratio 10.666, 95% CI 1.246-91.294, p=0.031). These results suggest that the risk of pancreatitis is heightened when didanosine and tenofovir are given together.