Morphologic and functional features of cyclic alternating pattern (CAP) sequences in normal NREM sleep

The Cyclic Alternating Pattern (CAP) is an EEG biphasic periodic activity of normal NREM sleep, generally organized in sequences of two or more cycles and correlated to long-lasting fluctuations in the level of arousal. The remaining NREM sleep is characterized by prolonged stationary activities or non-CAP (NCAP). Criteria for the detection of morphology and reactivity of CAP and NCAP segments are defined in the sleep recordings of 10 healthy young adults. Standard sleep variables and CAP rates, referred to the ratio of CAP time to Total NREM sleep time (CAPR/NREM) and to each NREM sleep stage, were scored for statistical inferences and correlations. CAPR/NREM may be considered an additional non-redundant sleep variable which determines the measure of arousal instability during NREM sleep. The relationship between CAP and the biphasic behavior of microarousals is discussed.     

Detection of Apoptosis in Peripheral Blood Cells of 31 Subjects Affected by Down Syndrome Before and After Zinc Therapy

Thirty-one patients affected by Down syndrome (DS) were investigated to study the presence of apoptosis in peripheral blood cells in relation to the plasma levels of zinc. Twelve patients had undergone therapy with ZnSO₄, while the remaining 19 were untreated. The presence of programmed cell death was evaluated by means of electron microscopy, in situ nick translation (NT), and agarose gel electrophoresis of DNA. These approaches evidenced the presence of apoptosis in peripheral blood cells of patients before therapy with ZnSO₄, while after zinc supplementation there was a reduction in the number of apoptotic cells. These results suggest that the process of programmed cell death in peripheral blood cells of patients with Down syndrome is related to the plasma levels of zinc ion.     

The nonvalue of retrospective peer comparison feedback in containing hospital antibiotic costs

Antibiotics have accounted for an increasing percentage of hospital pharmacy charges. Recently, an inexpensive method, automated peer comparison feedback, has been developed to influence physician use of resources. The documented success of several implementations of this strategy led to a one-year experiment to influence hospital antibiotic utilization. Each month, attending physicians in the top 50 percentiles for expenditure were notified of their status in relation to their peers. Expenditures by feedback and control groups were compared to determine whether feedback would result in reduced expenditures by individuals, or whether there would be a generalized reduction in expenditure by the entire group (Hawthorne effect). Over the year, no significant reduction in expenditure was noted. However, some important utilization patterns were identified. Although more surgical patients received antibiotics than did nonsurgical patients, surgical antibiotic costs were less. Surgical therapy was typically of shorter duration and involved the use of less expensive antibiotics. Multiple-antibiotic prescribing was less frequent on surgical services. Thirty percent of attending physicians were responsible for 80 percent of all antibiotic costs; 60 percent of those in this top group were members of the medical cohort. In conclusion: (1) As implemented in the current study, automated peer comparison feedback was not an effective method for reducing antibiotic utilization; (2) Differences in prescribing patterns between services may dictate the best strategies for improving antibiotic utilization; (3) More attention should be directed toward the relatively small "reference group" of physicians responsible for most hospital antibiotic prescribing.     

Clinical immunity in acute gastroenteritis caused by Norwalk agent.

To examine immunity in viral gastroenteritis, we challenged and then rechallenged 12 volunteers with Norwalk agent and evaluated symptoms, jejunal biopsies and serum antibody. With the first challenge, gastroenteritis developed in six volunteers but not in the others. When rechallenged 27 to 42 months later, the six who became ill initially again had gastroenteritis with jejunal lesions; in the six previously immune volunteers illness or jejunal lesions did not develop. Four of five ill volunteers had increases in serum antibody to Norwalk agent after both challenges. Serum antibody did not increase in three immune volunteers after either challenge. Four volunteers who had twice become ill underwent a third challenge four to eight weeks after their second illness. In one gastroenteritis developed; in three, it did not. These findings indicate two forms of immunity for viral gastroenteritis, one of short and the other of long duration. Factors other than serum antibody appear important in immunity to Norwalk gastroenteritis.     

A multicenter study on skin-test reactivity of human volunteers to venom as compared with whole body Hymenoptera antigens

Twenty-four control and 104 stinging insect—allergic patients were tested in this multicenter study, which compared the utility of individual venom and whole body extract (WBE) preparations for diagnosis. This study indicates that venom skin testing is more specific and more reliable than is testing with WBE. There was a high rate of WBE skin-test reactivity among controls. False-positive skin testing with venom was not a problem at concentrations of 1 μg/ml or less. Only one mild and easily treated adverse reaction occurred in this study.     

Variable-ratio schedules of timeout from avoidance: effects of anxiolytic drugs

Concurrent performances in rats were studied under conditions where responses on one lever postponed shock on an unsignaled avoidance schedule, and responses on another level produced periods of signaled timeout from avoidance on a variable-ratio schedule. This procedure resulted in relatively high rates of responding on the timeout lever, and provided a baseline which permitted simultaneous evaluation of drug effects on two different types of negative reinforcement (shock postponement vs timeout). Chlordiazepoxide and ethanol selectively increased responding on the timeout lever at low doses, while higher doses decreased responding on both levers. Two 5-HT(1A) agonists, buspirone and 8-OH-DPAT, had different effects. Buspirone decreased responding across all effective doses, but 8-OH-DPAT increased responding on both the timeout and avoidance levers, with greater increases noted in responding maintained by timeout. These results replicate and extend previous findings, and support the notion that traditional anxiolytic drugs like chlordiazepoxide and ethanol may increase the reinforcing properties of escape from an avoidance schedule. Differences between the behavioral effects of buspirone and 8-OH-DPAT may reflect differential activity at the 5-HT(1A) receptor or the dopaminergic properties of buspirone.     

Synthesis and Ring‐Opening Polymerization of Cyclic Butylene 2,5‐Furandicarboxylate

A new synthetic pathway for the polymerization of furan based polyesters is reported in this work. First, poly(butylene 2,5‐furandicarboxylate) cyclic oligoesters (COEs) are chemically synthesized by semi‐batch esterification. The structure of the COEs is confirmed by infrared spectroscopy, ¹H, and ¹³C‐NMR, while the molecular weight distribution of the COEs is determined by matrix‐assisted laser desorption/ionization time of flight mass spectroscopy. The cyclic oligoesters are then successfully polymerized via ring‐opening polymerization using tetrakis(2‐ethylhexyl)‐titanate as catalyst. Differential scanning calorimetry and ¹H‐NMR analysis unambiguously proves the formation of polymeric species. Both end‐group analysis from ¹H‐NMR spectrum and calculation through Flory–Fox equation give comparable estimates of the number average molecular weight: 5.8 × 10³ g mol^?1 and 7.8 × 10³ g mol^?1, respectively.