Regular Passage Research Articles

Establishment of Gastric Surface Mucous Cell Lines from Transgenic Mice Harboring Temperature-Sensitive Simian Virus 40 Large T-Antigen Gene

We succeeded in establishing two gastric surface mucous cell lines (designated as GSM06 and GSM10), which produce periodic acid-Schiff (PAS)- and concanavalin A (Con A)-positive glycoproteins, from a primary culture of gastric fundic mucosal cells of adult transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. At the permissive temperature (33°C), GSM06 and GSM10 cells grew until confluent monolayers were formed and have now been in culture for more than 9 months with regular passaging. Con A-horseradish peroxidase- and PAS-positive staining indicated that these cells retain the characteristics of gastric surface mucous cells. GSM06 cells showed temperature-sensitive growth in culture and expressed SV40 large T-antigen at the permissive temperature but not at a nonpermissive temperature (39°C). In contrast, GSM10 cells showed temperature-insensitive growth and expressed T-antigen at both permissive and nonpermissive temperatures. To our knowledge, this is the first report of the establishment of gastric surface mucous cell lines from animals. These immortalized cell lines with normal characteristics may serve as good experimental models for the basic and applied biology of gastric surface mucous cells.

Stimulation of cell division and DNA replication inPrototheca richardsiby passage through larval amphibian guts

SUMMARYPrototheca richardsi, an unpigmented heterotrophic alga, causes growth inhibition in amphibian larvae and has proved refractory to culturein Vitro.P. richardsireplication is dependent on regular passaging through tadpole digestive systems; uptake of thymidine by free-livingProtothecacells and incorporation into DNA are very low by comparison with leucine uptake and incorporation into protein, but DNA synthesis is detectable in cells isolated from tadpole intestines. DNA replication was elicited 6–8 h after ingestion in protothecans fed to tadpoles and subsequently re-isolated from them, providing that the tadpoles were fed subsequent to the ingestion. It appears that passaging through tadpole intestines provides an essential stimulus to maintaining an active cell division cycle inP. richardsi.

Establishment of conditionally immortalized epithelial cell lines from both colon and small intestine of adult H-2Kb-tsA58 transgenic mice.

Intestinal mucosal cells have proved difficult to culture in vitro. Many attempts have been made to develop long-term cultures of these cells either by direct culturing or by attempting to immortalize these cells by using a range of transforming viral genes, but with little success. The recent development of a transgenic mouse bearing a temperature-sensitive mutation of the simian virus 40 large tumor antigen gene (tsA58) has enabled us to initiate conditionally immortalized cultures of epithelial cells from both small intestinal and colonic mucosa of adult mice. Crypts were isolated from either the small intestines or colons of young adult mice and cultured at the permissive temperature (33 degrees C) in medium containing conditioned medium from a human colon carcinoma cell line, LIM1863. Crypts from both tissues yielded cultures of epithelial cells that have now been in culture for more than 12 months with regular passaging. The epithelial nature of the cells has been confirmed by staining with anti-keratin antibodies. The intestinal origin of the cells was demonstrated by the ability of the cells to synthesize low levels of both brush border peptidases and a disaccharidase. The levels of expression of these enzymes were modulated by the addition of sodium butyrate or phorbol myristate acetate to the medium, which resulted in an increase in the synthesis of the peptidases and a decrease in the synthesis of the disaccharidase. The cells proliferate continuously at the permissive temperature (33 degrees C), but proliferation ceases at the nonpermissive temperature (39.5 degrees C). To our knowledge, this is the first description of the establishment of epithelial cell lines from both small intestine and colon of the same mouse strain. The success reported here indicates that this transgenic mouse will be a useful source of tissue for the study of the mechanisms that control the proliferation and eventual differentiation and senescence of the cells of the intestinal mucosa. These mice will also be a useful source of cells for attempts to culture cells from other tissues that have proved difficult to culture in vitro.

Establishment of a Pneumococcal Septicemia Model in the Miniature Swine*

Human pneumococcal septicemia, the prominent postsplenectomy complication, was as yet difficult to study in the porcine model, since this species appeared to be fairly resistant against pneumococcal infections. We have used two strains of pneumococci (serotype 1 and 6B) both of which had been isolated from patients with systemic infection and both of which were maintained in a virulent state by regular mouse passage. After challenge with 10(9) type 1 pneumococci, however, only one of the 5 pigs developed fever, none showed profound hematological alterations and each animal exhibited a rapid clearance of bacteria from peripheral blood. By contrast, challenge of 7 animals with type 6B pneumococci resulted in a slower and incomplete bacterial clearance with persistent bacteremia for up to 24 hours. All animals developed fever and a profound leukopenia with less than 5,000 leukocytes/ml and 3 of the 7 animals died after injection of type 6B pneumococci. The results show that potentially the type 6B pneumococci can be successfully employed for studies of gram positive septicemia in the miniature swine.

Prestressed‐Concrete Railway‐Bridge Live‐Load Strains

The paper presents the findings of field studies into impactive loading generated by trains on a prestressed-concrete-girder bridge. The studies were conducted on Denison Creek bridge, in Central Queensland, Australia, which comprises simply supported spans of varying length and carries a single ballasted track of continuously welded rail on prestressed concrete sleepers. Bridge traffic is almost exclusively heavy-haul coal trains. Various defects were cut into one rail to model real defects such as wheel flats, wheel burns on rails, and broken or misaligned rails, Impacts from trains were measured via two independent strain-gage systems, with readings taken at the girder soffits. The heavy-haul coal traffic provided regular passages of long trains with axle loads known from mine weighings. The paper includes data on loading and number of wagons or locomotives involved in each sample for which impact data are presented. The strain readings quantify the variation of impact with degree of rail defect and also show that impacts may often exceed code values. The paper discusses the implications for bridge design.

Rigidity of segments of poly (ethyl methacrylate) in CCl14 solutions

AbstractCollegial dispersion forces originate from a coordination of the temporary electronic dipoles of a series of molecules. To insure this coordination the nuclei on a row have to replace their individual vibrations by coupled ones. Such row is then rigid. For polymers collegial forces can already be temporarily active in given parts of a solution but are regularly annihilated by intrusion of the solvent. However the regular passage through the rigid state modifies the distribution of the dipole moments during the interval that solvent or ligand molecules are in contact with the segment. In a rigid domain the correlation parameter of Kirkwood g is zero. The existence of such rigidity in solution is demonstrated by the low experimental value of gmA for the dipoles of the complexes between poly(ethyl methacrylate) and phenols. Due to the large number of segments that separate the complexes the classical explanation of stiffness of the chain due to individual interactions between neighbours does not hold.

On the migration of the Whimbrel,Numenius phaeopus, in Turkey

Abstract The Whimbrel (Numenius phaeopus) is a scarce but regular passage visitor in Turkey. Spring migration has its peak in April, autumn migration in August/September (medians are April 23th and August 29th). Detailed information on flock size, wintering, main resting sites etc. is given and compared with other Middle East countries.

Photospheric Models for Cool Giant Stars

AbstractModels for M and C giant stars differ from those for hotter stars by having complicated state equations and opacities dominated by lines from diatomic and polyatomic molecules. In addition many cool giants have atmospheres which are extended, and which cannot therefore be adequately modelled using a plane-parallel approximation. Mira variable stars have atmospheres which are even more extended due to the regular passage of shock waves through their atmosphere. In this review we will discuss recent modelling of such atmospheres and show comparisons with observations of variable and non-variable M stars.

New aspects of conservation of human fetal pancreatic ?-cells by the regular passage method

New aspects of conservation of human fetal pancreatic ?-cells by the regular passage method

Enhanced parasitization of platelets by plasmodium berghei yoelii

In previous studies plasmodia have been found by electron microscopy within human platelets naturally infected with Plasmodium vivax and within platelets of mice infected intraperitoneally with P. berghei. In both situations the number of parasitized platelets was low. An enhancement of platelet parasitization was attempted in order to study in greater detail the mechanisms and implications of such a phenomenon. Various in vitro incubation mixtures of normal mouse platelets and free merozoites of the 17X strain of P. berghei yoelii failed to produce any recognizable parasitization of platelets. In vivo, however, large numbers of invaded platelets were obtained by the use of massive intraperitoneal inocula of plasmodia (5 × 10 8 infected erythrocytes). By the 5th day of infection the proportion of parasitized platelets was 13·2 times higher in the animals receiving the large dose than in those receiving the regular passage inoculum (6 × 10 6 infected erythrocytes). Ultrastructural study of 266 intrathrombocytic parasites over eight days of infection failed to show schizogonic maturation beyond the trophozoite state.

Repeated establishment of diploid epithelial cell cultures from normal and partially hepatectomized rats.

A number of liver epithelial cell cultures were established from 10 to 12-d-old sucklings, 6 to 8-wk-old young adults, or from 2 to 18-month-old partially hepatectomized rats. Improvements in the methods for cell isolation and culture yielded replicating cells from every experiment and they were maintained for different periods with regular passages. The proliferative potential in vitro of adult rat liver cells could be increased if the rats were subjected to partial hepatectomy before cell isolation. In the early passages, the majority of the cells were found to have a true diploid karyotype as studied by the Giemsa-banding technique. Under the culture conditions described, a very high percentage of cells remained in the diploid range for, in most cases, at least 4 months and in some cases for up to 6 months. Afterward, the karyotype was unstable, but no "crisis" period was seen before the cells became aneuploid. Until this time, the growth characteristics of the cells also followed a normal pattern showing density dependent inhibition of division and a lack of markers associated with malignancy. The cultured liver cells exhibited a number of liver specific properties when they were maintained as a confluent monolayer. The early passages of diploid epithelial cell cultures derived from normal and regenerating rat liver are good models for studies of the regulation of cell division and the changes that are related to carcinogenesis.

Ultrasonic studies of anisotropy in cold-worked layer of used rail

The upper 3–5 mm of rail becomes severely cold worked with the regular passage of trains. Previous work has shown that the shear wave velocity in this upper layer is actually reduced by ∼ 10%. One of the most likely sources of this velocity reduction is the presence of a material texture in the upper region. In order to investigate the wave propagation properties of this upper region, several wafers of material, ∼ 4 mm thick, were removed from used and new rail. These wafers were removed from positions at different orientations relative to the longitudinal axis of the rail. Each wafer was secured in a device that permitted a 350° rotation of a pair of shear wave transducers propagating through the thickness of the samples. Transducer centre frequencies were above 10 MHz. The observed shear wave velocity change is compared to predicted changes for several textures observed in steel. A pattern exists indicating that a texture does exist in the cold-worked layer. Steel used for rail normally has a carbon content of 0·67–0·82%.

Validating a Limited — Cloze Procedure

Data from two studies were used to compare a limited-cloze procedure with the regular cloze procedure. The limited-cloze procedure differed from the regular cloze in one feature: the words deleted were randomly ordered and placed at the top of the test. For both studies the same passage was used to construct a regular cloze passage and an identical limited-cloze passage with the deleted words at the top. Subjects in each study were randomly assigned to two groups, one of which completed the regular cloze and the other which completed the limited-cloze. The limited-cloze was found to be as valid, reliable, objective, and practical a test as regular cloze, but less interpretable.

Immunopathology of Mouse Hepatitis Virus Type 3 Infection

Abstract Humoral and cell-mediated immune responses were studied in resistant and susceptible strains of mice infected with mouse hepatitis virus type III (MHV3). Virus was maintained by regular passages in susceptible DBA/2 mice and assayed in DBA/2 mice by LD50 determination. Normal resistant A strain mice were able to clear the virus from liver, brain, and serum within 7 days after infection. No neutralizing antibody was found. Transfer of serum from immunized A strain mice was not effective in protecting susceptible DBA/2 mice against challenge with virus. In A strain animals resistance to MHV3 developed rapidly during the 3rd week of life. During the period of susceptibility, newborns were protected neither by transplacental passages of anti-MHV3 antibodies nor by injection of “educated” thymus cells. These results suggest that the development of resistance to MHV3 infection in mice cannot be explained solely on the basis of humoral or cell-mediated immunity.

Boundary Layer Noise: The Relationship between Turbulent Shear Stress and the Turbulent Wall Pressure Field

This paper presents a recently developed model of wall turbulence that provides a new interpretation of the turbulent wall pressure field and hence a new approach to related acoustical and vibrational problems. The theory suggests that the turbulent transfer of momentum is effected by a moving array of horse-shoe vortex structures that are generated and maintained by a spatio-temporal instability of the sublayer flow. As a result of the interaction between these vortex systems and the basic flow, a characteristic pressure signature is generated on the wall directly beneath each vortex structure, the shape and average strength of the signature being related to the local turbulent shear stress distribution. The turbulent wall pressure field is attributed to the motion of the resultant pattern of pressure signatures over the wall, and is seen as an integral and essential part of the turbulent shear stress mechanism. A new “pulse amplitude modulated” model of the pressure field is accordingly proposed in which the pressure at a fixed point on the wall is generated essentially at a single, characteristic frequency (related to local wall shear stress) by the regular or near regular passage of pressure pulses whose amplitudes vary randomly over a range determined by the ratio of boundary layer to sublayer thickness (i.e., over several orders of magnitude).

RADAR STUDIES OF SONGBIRD MIGRATION IN COASTAL NEW ENGLAND*

RADAR STUDIES OF SONGBIRD MIGRATION IN COASTAL NEW ENGLAND*

On the distfibution and migration of Muscicapa mugimaki

Mugimaki Flycatcher breeds in Sakhalin and Siberia and winters in southern Asia, passing Japan as a transient. Udagawa considered it an autumn migrant, which occurs only as stragglers in spring (May and March, the latter being doubtful and his theory of correlation with snow line is not tenable). The author adds five spring records (May) from Hokkaido, Honshiu and S. Korea, which prove its regular passage in this season, though less notice than in autumn, when it moves slowly in broad front with its number multiplied by young birds. Birds might stop and breed if they found a suitable breeding environment before reaching finar destination. Udagawa's late May observation of a pair in Fuji Mt., Honshin, might be such an example. Suggestion is given of its migration routes.

‘The Haven Finding Art’

People often think that early seafarers must have clung to the coast, but there is plenty of evidence that from the earliest times seamen have not only ventured out of sight of land but have conducted regular passages across the open sea. No doubt, however, landmarks did provide the earliest aid to navigation and in the eastern Mediterranean where the science was born, ships would not have been out of sight of land for more than a day or two.

Birds within Cities

SINCE Gilbert White's recording of the house-martins nesting in Fleet Street and the Strand, ornithologists have never failed to interest themselves in birds about cities. A day-to-day census of the birds of the Liverpool Cathedral Wild Birds' Sanctuary, established in 1927 in an old quarry, now a cemetery, in the heart of Liverpool slums and five miles from the nearest trace of open country, has recently been completed by Mr. Eric Hardy. Thirty species are recorded: house-sparrow, starling, robin, blue tit, hedge-sparrow, song thrush, blackbird, wren, greenfinch, domestic pigeon, great tit, missel-thrush, chaffinch, rook, linnet, redwing, herring-gull, common gull, kestrel, jackdaw, cole-tit, yellow-hammer, gold-crest, chiffchaff, willow-wren and whitethroat, the first twelve of which nest. The goldcrest is now a regular spring passage migrant since the establishment of food tables, etc., though the first specimen was recorded in March, 1931 (Proc. Liverpool Nat. Field Club, 1931, p. 41), while the willow-warbler soon established itself as a regular passage migrant, spring and autumn (Liverpool Review, Annual Report, February, 1933).

The Boy in the Library

THERE was once a small boy with a large head and a frown above his short‐sighted eyes who, every Friday night in life, with a large bundle of books under his arm, passed through the grey streets of the town of Greenock. There was the look of a student about this pug‐nosed youngster, and decent motherly persons, marking his regular passages to and from the Watt Library, spoke of him as “an awfu' boy for books.” He seemed to such, no doubt, a scholar in embryo, a professor in the making; and you know what women are with the shy and retiring of the other sex. But had some knowing person stopped that earnest lad and examined a typical batch of titles, he would, I fear, have had to laugh at the preposterous variety of it, at the incredible mixture of good and bad with which the boy satisfied his craving to read.