The effect of nitrogen dioxide exposure on the release of surfactant isolated from neonatal rabbit type II pneumocytes in culture

Nitrogen dioxide (NO2) is a well-known environmental air toxin, produced from a variety of sources, including cigarette smoke. Because of the growing knowledge of the harmful effects of passive smoking on children, we decided to study the effect of NO2 exposure on the release of surfactant from isolated neonatal type II pulmonary epithelial cells. After isolation from 1 to 4 day old rabbits, type II epithelial cells were allowed to adhere for 18 hours, washed, media changed, and were exposed to either 5% CO2 in room air or NO2, 5 ppm, for 2 hours (all results mean +/- sd; comparisons, paired t-test). There was no difference in cell number or viability prior to exposure. Cells exposed to NO2 had an increase in LDH release [LDH activity in media/(LDH in media+cells) x 100], air 12.6 +/- 2.2%, NO2 21.7 +/- 3.7%, (p < 0.05). NO2-exposed cells also had an increase in total phospholipid (microgram/cell culture dish) in media compared to air exposed, air 170.13 +/- 7.54, NO2 195.15 +/- 11.2, (p < 0.05). 3H-choline incorporation as a precursor to disaturated phosphatidylcholine (DSPC) was also conducted during exposure to either air or NO2. Incorporation of 3H-choline into surfactant lipid was increased in media from cells after NO2 exposure compared to air, 58.23 +/- 15.16 air, 76.81 +/- 19.86 NO2 (cpm/microgram protein; p < 0.05). These results show that 2 hours of 5 ppm NO2 exposure is associated with an increase in release of surfactant from neonatal type II cells in culture.     

The analysis of fatty alcohols and acids asp-(methylthio)-benzoate esters

Thep-(methylthio)-benzoate ester of fatty alcohols is investigated. This derivative shows either a molecular ion or M-168 m/e peak in its mass spectrum and mixtures may be qualitatively analyzed directly by mass spectrometry. The compounds absorb strongly in the ultraviolet, allowing quantitative analysis by high performance liquid chromatography to 200 pmol.     

Respiratory effects of extradural analgesia after lower abdominal surgery

Blood-gas tensions, FRC and volume of trapped gas (VTG) in the lung were measured in patients on the day before lower abdominal gynaecological surgery, and twice on the day following surgery, before and after establishing lumbar extradural block (EDB) using 0.5% bupivacaine to provide analgesia after operation. FRC and VTG were measured with the closed-circuit helium-dilution technique. Mean VTG was 175 ml before operation and 275 ml after operation. PaO2 decreased significantly after operation, and the changes in FRC and VTG that occurred were related qualitatively. EDB did not significantly alter FRC, VTG or PaO2. Individual changes in FRC could not be related to changes in VTG or PaO2. Although EDB provided effective analgesia, the variables measured did not indicate that EDB conferred an immediate respiratory advantage.     

Behavioral and sociometric methods of identifying cooperators, competitors, and individualists: Support for the validity of the social orientation construct.

Cooperative, competitive, and individualistic social orientation of 132 4th–6th graders was assessed using a behavioral choice point and a sociometric measure. The classifications based on responses to the 2 measures are consistently related, and results are interpreted in terms of the convergent validity of the social orientation construct. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metabolic safety-margins do not differ between cows of high and low genetic merit for milk production

Three galactopoietic stimuli, frequent milking (4X), bovine somatotrophin (bST) and thyroxine (T4) were used in an additive stair-step design to achieve maximum output (metabolic capacity) in six peak-lactation cows of high genetic merit (HT) and six of low genetic merit (LT). A further six of each merit were untreated controls (HC, LC). Milk yield was increased significantly by 4X, increased further by the combination of 4X and bST and increased further still and significantly by the full combination of 4X, bST and T4. The magnitude of the yield response to the sequence of treatments did not differ significantly between HT and LT. The yield response to 4X and bST was sustainable without significant loss of body weight or body condition score for the 6 weeks during which these stimuli were administered. The response to the full combination, which included T4, was accompanied by significantly elevated heart rate and significant loss of body weight and condition compared with the combination of 4X and bST. As a result, treatments were discontinued, on an individual cow basis, before completion of this 6-week phase. Time on experiment did not differ between HT and LT. The results do not support the commonly held belief that selective breeding of dairy cows for high milk production has rendered them markedly more susceptible to metabolic disturbances.     

A picture integration task for measuring iconic memory in schizophrenics.

Two previous studies by the 1st author et al (1977) and G. Sperling (1960) using different techniques (partial report and backward masking) have found at least some subgroups of schizophrenics deficient in iconic memory. Both hypothesized that the icon in some schizophrenics might be either weakly formed, limited in capacity, or abnormal in duration, but neither study was able to test the qualities of the icon independent of possible transfer difficulties. The present study with 50 male 18–55 yr old psychiatric patients (35 schizophrenics and 15 nonpsychotics) developed a picture integration task that was analogous to C. W. Eriksen and J. F. Collins's (1973) random dot integration. With this task, the capacity and decay of the icon independent of transfer to short-term store was assessed. The icon itself was found intact in all schizophrenics. Other explanations are suggested for schizophrenics' inadequate partial report and backward masking performance. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of the absorption spectrum of polytetrafluoroethylene in the near millimetre region by an untuned cavity

The absorption spectrum of polytetrafluoroethylene has been measured between 3 and 15 cm^?1, a region which until now has been virtually unexplored. Absorption was found to arise almost entirely from amorphous regions of the sample and absorption in crystalline regions is small. A novel feature of the investigation is that measurements are made in an untuned cavity which has the advantage for low loss materials, that losses from reflection, scatter, and diffraction become unimportant. Loss measurements can be made on samples even when they are in the form of fine powder.