Quetiapine-induced Bradycardia and Hypotension in the Elderly-A Case Report.

Quetiapine is increasingly used for the treatment of behavioral and psychological symptoms of dementia in elderly patients. Among the many potential side effects of second-generation antipsychotics, the sudden onset of cardiac abnormality is a particularly important side effect to consider due its fatal implications. Elderly patients may be particularly vulnerable to these cardiac-related side effects due to the likelihood that they have multiple existing health conditions (e.g., heart disease, high blood pressure, diabetes) as well as age-related changes in their pharmacokinetics and pharmacodynamics and differences in their receptor binding profiles. We present a case of an elderly man with a history of heart disease who developed symptomatic bradycardia and hypotension simultaneously while taking quetiapine. After dose reduction and withdrawal of quetiapine, a time sequential improvement of bradycardia and hypotension monitored by repeated electrocardiogram and blood pressure checks suggests a relationship between the higher dosage of quetiapine and cardiac abnormalities. Other factors such as aging itself and chronic heart failure might be associated with cardiac distress. Elderly patients on quetiapine, particularly at higher dosages, should be continually and closely monitored for any symptoms of cardiac distress.

Evaluation of arbekacin anti-MRSA agents for adult in Japan.

There are a limited number of reports that compare the clinical efficacy of anti-MRSA agents such as arbekacin (ABK), vancomycin (VCM), teicoplanin (TEIC) and linezolid (LZD). There is a tendency for these four agents to show variation in the inflammatory response parameters, in C-reactive protein (CRP) and in white blood cell count (WBC), depending on the administration period. There was no significant difference among the agents in analysis of variance (ANOVA) in the group of days 1-3 (p = 0.0536) but there was some significant difference in the group of days 4-7, as well as days 8-14 (p < 0.001, p < 0.01) in relative variation rate of CRP. Furthermore, we compared in more detail the groups of LZD, VCM and ABK, with a significant decrease of CRP, each of which showed more decrease in comparison with the group of TEIC in the period days 4-7 (p < 0.01). We took 1-hr serum level after days 3-4, with the ABK treatment as the peak concentration (C(peak)). Having made nonlinear logistic regression analysis of CRP and C(peak)/MIC, we concluded that the decrease rate estimable by early inflammatory effect could be decreased to some 40%, assuming that C(peak)/MIC shows the high value within 4 days after ABK treatment.

Preinspiratory calcium rise in putative pre-Botzinger complex astrocytes.

The neural inspiratory activity originates from a ventrolateral medullary region called the pre-Bötzinger complex (preBötC), yet the mechanism underlying respiratory rhythmogenesis is not completely understood. Recently, the role of not only neurons but astrocytes in the central respiratory control has attracted considerable attention. Here we report our discovery that an intracellular calcium rise in a subset of putative astrocytes precedes inspiratory neuronal firing in rhythmically active slices. Functional calcium imaging from hundreds of preBötC cells revealed that a subset of putative astrocytes exhibited rhythmic calcium elevations preceding inspiratory neuronal activity with a time lag of approximately 2 s. These preinspiratory putative astrocytes maintained their rhythmic activities even during the blockade of neuronal activity with tetrodotoxin, whereas the rhythm frequency was lowered and the intercellular phases of these rhythms were decoupled. In addition, optogenetic stimulation of preBötC putative astrocytes induced firing of inspiratory neurons. These findings raise the possibility that astrocytes in the preBötC are actively involved in respiratory rhythm generation in rhythmically active slices.

Synchronized spike waves in immature dentate gyrus networks.

At early developmental stages, immature neuronal networks of the neocortex and hippocampus spontaneously exhibit synchronously oscillating activities, which are believed to play roles in normal circuit maturation. The tissue development of the dentate gyrus (DG) in the hippocampal formation is exceptionally late compared with other brain regions and persists until postnatal periods. Using patch-clamp recording and functional multineuron calcium imaging, we found that the DG networks of postnatal day (P)3-7 mice spontaneously generated traveling waves of action potentials, which were initiated at the upper blade of the granule cell layer and propagated to the lower blade. The propagation was dependent on glutamatergic and electrical synapses, but not on GABAergic receptor activity. Remarkably, the DG waves were almost completely abolished in offspring born to female rats exposed to restraint stress during pregnancy. In the prenatally stressed offspring, DG granule cell dendrites developed normally until P3 and showed atrophy by P9. Thus, the DG waves may be required for the maturation of DG granule cells.