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Biomedical subjects

P A Rinaldi

Publications and source records attributed to P A Rinaldi.

3 recordsLinked to original sources
PubMed1998

Melatonin production: proteasomal proteolysis in serotonin N-acetyltransferase regulation.

The nocturnal increase in circulating melatonin in vertebrates is regulated by 10- to 100-fold increases in pineal serotonin N-acetyltransferase (AA-NAT) activity. Changes in the amount of AA-NAT protein were shown to parallel changes in AA-NAT activity. When neural stimulation was switched off by either light exposure or L-propranolol-induced beta-adrenergic blockade, both AA-NAT activity and protein decreased rapidly. Effects of L-propranolol were blocked in vitro by dibutyryl adenosine 3',5'-monophosphate (cAMP) or inhibitors of proteasomal proteolysis. This result indicates that adrenergic-cAMP regulation of AA-NAT is mediated by rapid reversible control of selective proteasomal proteolysis. Similar proteasome-based mechanisms may function widely as selective molecular switches in vertebrate neural systems.

Adrenergic beta-Agonists↗
PubMed1997

Forced-air warming is no more effective than conventional methods for raising postoperative core temperature after cardiac surgery.

OBJECTIVE: To determine whether postoperative forced-air warming of cardiac bypass patients in the intensive care unit (ICU) results in faster rate of warming and improved outcomes compared with more conventional ICU warming methods. DESIGN: Prospective randomized effectiveness study. SETTING: Three hundred fifty-bed university-affiliated hospital. PARTICIPANTS: Sixty consenting randomized patients from a consecutive series of 84 patients undergoing routine adult cardiac surgery. INTERVENTIONS: One group of patients received usual patient care, which includes warm blankets and overhead heat lamps. Patients in the other group were placed under forced-air warming devices on arrival in the ICU. Sixty consenting patients (30 in each group) were randomly assigned to one or the other method of warming. The remaining 24 patients refused randomization and self-selected a treatment group. MEASUREMENTS AND MAIN RESULTS: Results are presented for the randomized groups. Core temperature, measured by pulmonary artery catheter thermistor, increased in both groups at the rate of 0.25 degree C per hour. No statistically or clinically significant differences were found between the group for whom the warming device was used and the standard care group in the incidence of postoperative cardiac arrhythmia, duration of time in the ICU, or any other clinical variable. CONCLUSIONS: There is no evidence from this study to warrant use of forced-air warming devices for the care of postoperative cardiac surgical patients in the ICU.

Aged↗