Extra-alveolar veins are contiguous with, and leak fluid into, periarterial cuffs in rabbit lungs.

We previously observed physiological evidence that arterial and venous extra-alveolar vessels shared a common interstitial space. The purpose of the present investigation was to determine the site of this continuity to improve our understanding of interstitial fluid movement in the lung. Orange G and Evans blue dyes were added to the arterial and venous reservoirs, respectively, of excised rabbit lungs as they were placed 20 cmH2O into zone 1 (pulmonary arterial and venous pressures = 5 cmH2O, alveolar pressure = 25 cmH2O).

Time required to achieve homogeneity of test substances added to dog feed.

The homogeneity of test substances in a carrier (animal feed) is a critical factor in conducting long-term feeding studies in laboratory animals. A method for determining the adequate amount of mixing to achieve homogeneity by a mixer of the type described has been determined when 2 distinctly different compounds are added to ground dog feed. Nicotinic acid and butylated hydroxyanisole at a concentration of 1% were separately mixed with the dog feed for 15, 30, 45, 60, and 120 min to determine optimum mixing time.

Performance characteristics of methods of analysis used for regulatory purposes. Part II. Pesticide formulations.

The precision parameters of the method-performance (collaborative) studies published in the AOAC Journal from 1915 through 1990 for pesticide formulations have been recalculated on a uniform basis by the International Union of Pure and Applied Chemistry 1987 protocol. About 93% of the 953 accepted assays, which are predominantly gravimetric (G), volumetric (V), and gas (GC) and liquid (LC) chromatographic methods, exhibit relative standard deviations among laboratories (RSDR) that are generally less than 2 times the values predicted from the Horwitz equation: RSDR (%) = 2 exp (1-0.5 log C), where C is the concentration expressed as a decimal fraction.

Gravity is a minor determinant of pulmonary blood flow distribution.

Regional pulmonary blood flow in dogs under zone 3 conditions was measured in supine and prone postures to evaluate the linear gravitational model of perfusion distribution. Flow to regions of lung that were 1.9 cm3 in volume was determined by injection of radiolabeled microspheres in both postures.

Benzo[a]pyrene-induced skin damage and tumor promotion in the mouse.

Epidermal cell kinetics and DNA adduct levels, and skin morphological changes were measured following weekly topical applications for 29 weeks of high (16, 32 and 64 micrograms) benzo[a]pyrene (B[a]P) doses to female ICR/Harlan mice, in order to investigate the relationship of these parameters to the timing, incidence and morphology of the elicited tumors. During the tumor latency period, [3H]thymidine labeling index, mitotic index, epidermal cell stacking, incidence of pyknotic and dark basal keratinocytes and labeled mitoses were periodically measured, as were nuclear area and DNA content. DNA adducts in skin epidermis were measured by an ELISA method over a period of 9 weeks of single weekly applications of 64, 32, 16 or 8 micrograms B[a]P.

Intestinal absorption of the octapeptide SMS 201-995 visualized by fluorescence derivatization.

The absorption of an intact oligopeptide was investigated in rat and dog small intestine using the metabolically stable somatostatin analogue SMS 201-995. The synthetic octapeptide was coupled to 4-nitrobenzo-2-oxa-1,3-diazol to have a fluorescent label for the direct visualization. The 4-nitrobenzo-2-oxa-1,3-diazol-labeled peptide was active in displacing the corresponding hormone 125I-Tyr3-SMS 201-995 (Sandostatin; Sandoz Pharmaceuticals, Basel, Switzerland) from its high-affinity binding site in rat cortex membranes with an IC50 = 4.

Abdominal distension alters regional pleural pressures and chest wall mechanics in pigs in vivo.

Abdominal distension (AD) occurs in pregnancy and is also commonly seen in patients with ascites from various causes. Because the abdomen forms part of the "chest wall," the purpose of this study was to clarify the effects of AD on ventilatory mechanics. Airway pressure, four (vertical) regional pleural pressures, and abdominal pressure were measured in five anesthetized, paralyzed, and ventilated upright pigs.

Issues in the risk assessment of chromium.

Although hexavalent chromium is well established as a human carcinogen by the inhalation route, there are significant uncertainties in the quantitative estimation of cancer risk. One of the important uncertainties is the assumption that the carcinogenic potency, determined under conditions of occupational exposure where most workers were cigarette smokers, applies to the nonsmoking individual in the general population. There is substantial evidence that carcinogenicity is a function of the rate of cell turnover in the target tissue.

Flow through zone 1 lungs utilizes alveolar corner vessels.

We have previously observed flows equivalent to 15% of the resting cardiac output of rabbits occurring through isolated lungs that were completely in zone 1. To distinguish between alveolar corner vessels and alveolar septal vessels as a possible zone 1 pathway, we made in vivo microscopic observations of the subpleural alveolar capillaries in five anesthetized dogs. Videomicroscopic recordings were made via a transparent thoracic window with the animal in the right lateral position.

Program planning for the certified emergency nursing review course.

Preparation for the CEN Review Course is time-consuming, but when the above steps are followed, it will prove successful and rewarding for both the sponsors and participants. As members of a professional association and coordinators of an education offering, a vital role as a CE provider can be filled. It is through the efforts of those planning the course that the ENA and its members are able to meet the CE needs of nurses.

Immunoaffinity column coupled with solution fluorometry or liquid chromatography postcolumn derivatization for determination of aflatoxins in corn, peanuts, and peanut butter: collaborative study.

An AOAC/IUPAC (International Union of Pure and Applied Chemistry) collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column for the determination of aflatoxin. The test portion is extracted with methanol-water (7 + 3), filtered, diluted to less than 30% methanol with water, and applied to the affinity column. The column is washed with water and the concentrated aflatoxins are eluted with methanol.

AaDO2 as a predictor of pulmonary hypertension resulting from pulmonary emboli.

The authors examined the records of all patients referred for right heart catheterization between 1963-84 because of persistent dyspnoea after one or more episodes of pulmonary emboli. Patients with a history of congestive heart failure, angina, restrictive or obstructive pulmonary disease that could explain their symptoms were excluded. Catheterization was performed 15.

[111In-DTPA-D-Phe1]-octreotide, a potential radiopharmaceutical for imaging of somatostatin receptor-positive tumors: synthesis, radiolabeling and in vitro validation.

Somatostatin receptor-positive human tumors can be detected using radioiodinated analogues of somatostatin, both in vitro and in vivo. [123I-Tyr3]-octreotide has been successfully used in the visualization of somatostatin receptor-positive tumors by gamma camera scintigraphy, but this radiopharmaceutical has some major drawbacks, which can be overcome with other radionuclides such as 111In. As starting material for a potentially convenient radiopharmaceutical, a diethylenetriaminopentaacetic acid (DTPA) conjugated derivative of octreotide (SMS 201-995) was prepared.

Surfactant replacement improves lung recoil in rabbit lungs after acid aspiration.

We tested the hypothesis that surfactant replacement would be beneficial in the acid-aspiration model of acute lung injury. HCl (0.1 N, 2 ml/kg) was injected into the trachea of excised rabbit lungs (n = 8).

Precision parameters of methods of analysis required for nutrition labeling. Part I. Major nutrients.

Major components of foods and feeds are fat, protein, and carbohydrates. Fat and protein are determined by direct measurements that are interpreted as the quantity of the constituent. Carbohydrates are usually calculated by difference.

Prone position reverses gravitational distribution of perfusion in dog lungs with oleic acid-induced injury.

Although oxygenation improves in patients with the adult respiratory distress syndrome and in animals with oleic acid- (OA) induced acute lung injury when they are turned from the supine to the prone position, the mechanism(s) by which this improvement occurs is not known. Several groups have speculated that this improvement results from preferential edema accumulation in the dorsal lung regions and redistribution of perfusion away from these regions when the patients are turned to the prone position. We used radiolabeled microspheres to measure the regional distribution of perfusion (Qr) to the dorsal, mid, and ventral lungs of eight dogs in vivo in the supine and prone positions, before and after inducing acute lung injury with OA, and correlated the Qr observed after injury with the degree of regional extravascular lung water (EVLWr).

[Centroblast morphology: a morphometric evaluation by means of computer-aided image analysis].

In cytologic preparations, cell images from 30 cases of high grade malignant Non-Hodgkin's lymphoma (NHL) and 10 cases of tonsillitis have been analysed using a colour TV microscope system, high resolution scanning and image processing. Multivariate analysis of 30 cell features allowed satisfying recognition and discrimination of centrocytes, centrocyte-like centroblasts, ordinary centroblasts and multilobated centroblasts. In addition, according to their image analytical data, the ordinary centroblasts from NHL formed 5, and those from tonsillitis 4 well defined, homogeneous clusters.

Postnatal development of the photoreceptor inner segment of the retina in dogs.

In dogs, the retina develops during the postnatal period in a manner similar to that in other animals born with closed eyelids. Photoreceptor inner segments are initially observed as a cytoplasmic bulge protruding sclerad through the external limiting membrane. Outer segment formation begins when a centriole within the inner segment attaches to the distal inner segment cell membrane.

Regulation of carcinogens in terms of life shortening.

Because of the difficulty in using the results of conventional quantitative risk assessment in the regulation of carcinogens, an approach to setting carcinogen standards is presented based on the reduction of cancer-induced life span shortening to statistically nonsignificant levels. An argument is made that the time of cancer occurrence is more important than the risk of cancer. The rationale is that the objective of carcinogen control is to delay the single-risk time of cancer occurrence.

Precision parameters of standard methods of analysis for dairy products.

The available collaborative studies for standard methods of analysis for various constituents of milk and milk products were examined in an attempt to assign specific repeatability and reproducibility precision parameters to these methods. The different collaborative assays for the primary constituents (moisture/solids, fat, protein), the nutritionally important elements (calcium, sodium, potassium, phosphorus), and miscellaneous analytes/physical constants (ash, lactose, salt, freezing point) produced different estimates of the precision parameters for the same method. A suitable summary of the precision estimates from collaborative studies is given by the reproducibility relative standard deviation, RSDg, which is relatively constant within a product and permits comparisons across products.