Electrophysiologic effects of propranolol on sinus node function in patients with sinus node dysfunction

The electrophysiologic effects of intravenously administered propranolol (0.1 mg/kg) on three parameters of sinus node function were examined in ten symptomatic patients with sinus node dysfunction. The patients ranged in age from 26 to 79 years. Symptoms ranged from fatigue to frank syncope. Sinoatrial (SA) block and sinus pauses were observed in one patient; sinus pauses alone were observed in three patients. Five (5/10) patients had intraatrial block; three (3/10) patients had atrioventricular block; four (4/10) patients had an intraventricular conduction disturbance. At the time of electrophysiologic study, two patients had a control spontaneous sinus cycle length that exceeded 1000 msec. Following propranolol, the mean spontaneous cycle length increased by 17.4% (924 to 1085 msec, P less than 0.005) and spontaneous second degree SA block reappeared in the one patient. The maximum escape cycle ranged from 116% to 229% of the prepacing spontaneous cycle length and was considered to be prolonged in two of ten patients. Propranolol had no significant effect on the maximum escape cycle/prepacing cycle length X 100 (%). The estimated sinoatrial conduction time (SACT) was determined in seven patients and ranged in value from 120 to 238 mes. Propranolol increased the mean value of the estimated SACT from 179 to 213 msec, P less than 0.025. Propranolol may cause marked bradyarrhythmias in some patients with sinus node dysfunction, and should be used with caution in these patients.     

Effects of calcium and magnesium ions upon fat absorption by sacs of everted hamster intestine

Sacs of everted hamster jejunum were incubated with fatty acid and monoglyceride in bile salt solutions either with or without added salts of calcium and magnesium. At very low concentrations of Ca2+ and Mg2+, the intestine produced very few chylomicrons. However, at physiological concentrations of the ions, the gut-preparation released numerous chylomicron-like particles into the serosal fluid.     

Life events and two-year outcome in schizophrenia.

Tested the hypothesis that higher aggregate levels of objective life-events stress before a 1st-time psychiatric admission for schizophrenia will relate to better outcome. Ss were 15–55 yr old schizophrenics classified by any 1 of 3 methods from a larger investigation of 1st-admission inpatients. Hospitalization and 2-yr follow-up assessments were made with structured, standardized interview schedules. 31 Schneiderian, 39 New Haven Index, and 41 DSM-II schizophrenics were then bifurcated into high- and low-event groups. The test for different group outcomes was made with a MANOVA of 5 measures of outcome functioning. Where the MANOVAs were significant, t tests were employed to determine group differences in specific outcome areas. Findings support the hypothesis for Schneiderian and New Haven diagnostic criteria. Further analyses suggested that results were not attributable to demographic factors, premorbid status, severity of pathology at admission, or interim stress levels and probably were not exclusively the effect of precipitating life events shortly before hospitalization. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of obstetric medication on auditory habituation in the newborn.

Examined auditory habituation in 24 newborns, using E. Conway and Y. Brackbill's (1970) procedure, with the addition of a test for dishabituation, and state observations. Significant response decrement was observed in all infants; a majority responded to the dishabituation stimuli. Rate of habituation varied with number of state changes, intensity of stimulation required to initially elicit a response, and, for infants initially responsive to an 80-db signal, level of obstetric medication (analgesics and anesthetics). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The open and closed mind: A review of dogmatism.

Research on Rokeach's concept of dogmatism is reviewed and structured into 10 areas: authoritarianism, the Dogmatism scale, personality, adjustment, group behavior, parent-child relationships, time perception, cognitive inconsistency, problem solving, and learning. Findings generally support the validity of Rokeach's concept, particularly as a generalized theory of authoritarianism independent of ideological content. Evidence suggests that a "dogmatic personality" style exists and may be readily identified. Limitations of the work done on dogmatism are noted and suggestions for specific areas of future research are made. (4 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Abortion surveillance--United States, 1995

CONDITION: Since 1990 (i.e., the year in which the number of abortions was highest), the annual number of abortions in the United States has decreased by 15%. REPORTING PERIOD COVERED: This report summarizes and reviews information reported to CDC regarding legal induced abortions obtained in the United States during 1995. DESCRIPTION OF SYSTEM: For each year since 1969, CDC has compiled abortion data received from 52 reporting areas: 50 states, the District of Columbia, and New York City. RESULTS: In 1995, a total of 1,210,883 legal abortions were reported to CDC, representing a 4.5% decrease from the number reported for 1994. The abortion ratio was 311 legal induced abortions per 1,000 live births, and the abortion rate was 20 per 1,000 women aged 15-44 years, the lowest ratio and rate recorded since 1975. Women who were undergoing an abortion were more likely to be young, white, and unmarried; most were obtaining an abortion for the first time. Approximately half of all abortions (54%) were performed at < or =8 weeks of gestation, and approximately 88% were performed before 13 weeks. Approximately 16% of abortions were performed at the earliest weeks of gestation (< or =6 weeks), approximately 17% at 7 weeks of gestation, and approximately 21% at 8 weeks of gestation. Few abortions were provided after 15 weeks of gestation -- approximately 4% of abortions were obtained at 16-20 weeks, and 1.4% were obtained at > or =21 weeks. Younger women (i.e., women aged < or =24 years) were more likely to obtain abortions later in pregnancy than were older women. INTERPRETATION: Since 1990, the number of abortions has declined each year. Since 1987, the abortion-to-live-birth ratio has declined; in 1995, it was the lowest recorded since 1975. This decrease in the abortion ratio reflects a trend that a lower proportion of pregnant women obtain induced abortion. ACTIONS TAKEN: The number and characteristics of women who obtain abortions in the United States should continue to be monitored so that trends in induced abortion can be assessed, efforts to prevent unintended pregnancy can be evaluated, and the preventable causes of morbidity and mortality associated with abortions can be identified and reduced.     

Community guide recommendations and state level tobacco control programmes: 1999-2004

Objective

To identify the level of effort state tobacco control programmes and partners have expended on interventions recommended by the community guide and how those efforts have changed over time between 1999 and 2004.

Design

Longitudinal study.

Setting

United States.

Participants

State tobacco control partners, including the state health department, voluntary agencies and tobacco control coalitions.

Main outcome measure

We used the Strength of Tobacco Control survey responses in 1999, 2002 and 2004 to calculate the mean proportion of state tobacco control partners working on recommended interventions and subsequently analysed changes in effort over time.

Results

The proportion of state tobacco control partners working to promote clean indoor air legislation remained at more than 70% in all three years. The proportion working to increase taxes on tobacco rose significantly between 1999 and 2002 (from 54% to 70%), and those working to reduce patient costs for tobacco cessation treatments never exceeded 31% in any year. Use of mass media targeting youths decreased significantly in all years (from 40% to 32% to 26%), and the proportion of state tobacco control partners participating in a quitline has increased steadily and significantly in all years (from 24% to 36% to 41%). The level of effort in each area varied widely between states and over time.

Conclusions

State tobacco control partners are implementing evidence based interventions, but more focus is needed on the tobacco cessation and mass media campaign components of comprehensive tobacco control programmes.     

Combining Data Longevity with High Storage Capacity—Layer‐by‐Layer DNA Encapsulated in Magnetic Nanoparticles

In this paper the practical density of long‐term DNA storage is increased. Specifically, the DNA weight loading of silica sphere DNA storage is increased to 3.4 wt%, a ten‐fold increase compared to the previous state‐of‐the‐art. By applying a Layer‐by‐Layer (LbL) design with alternating layers of DNA and a polycationic molecule, namely polyethyleneimine (PEI), another dimension to DNA surface binding onto magnetic nanoparticles is added. A protective silica layer is grown on top of the multilayered nanoparticles to shield the DNA from external sources of damage. Accelerated aging experiments of the nanoparticles and the subsequent quantification of DNA stability via qPCR show a significantly lower degradation rate compared to unprotected DNA. The novel material is compared to previous DNA storage technologies, outperforming those in DNA storage density as well as stability. Finally, the storage of an 83 kB digital file in DNA through a successful readout of a 4991 oligonucleotide pool is demonstrated from particle encapsulation, through accelerated aging, to sequencing.     

Functional studies of synthetic gramicidin hybrid ion channels in CHO cells

The function of a gramicidin hybrid ion channel in living Chinese hamster ovary (CHO) cells was investigated by the patch clamp method. The synthetic ion channel 1 consists of two cyclohexyl ether amino acids that link two mini-gramicidin strands. With 1 at a concentration of 1.0 microM, an increase in the whole-cell membrane conductance was observed after 1.37 min. The conductance showed larger currents when Cs(+) was used as charge carrier than when Na(+) and K(+) were used. In single-channel recordings with Cs(+) as charge carrier, the substance showed comparable single-channel amplitudes in the membrane of living cells and artificial black lipid bilayers. In addition to functioning as a cation channel, compound 1 appeared to be a water channel. Exposure of the CHO cells to an extracellular hypoosmotic solution did not substantially change the cell volume. Extracellular hypoosmotic conditions in the presence of 1 increased the cell size to 146.5 % that of the control. Thus, the synthetic hybrid channel 1 can function as a cation channel with some Cs(+) specificity, and as a water channel in CHO cells.