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PubMed1976

Studies on normal human bone marrow cultures in controlled environment thin-film culture systems.

Two thin film culture systems, the controlled environment steady state system (SS) and the rocker tube configuration of that system (RT), were used to identify some of the conditions that appear to maintain morphologic and functional characteristics of cells of human bone marrow explants in vitro. The systems configuration assured continual gassing, control and easy monitoring of the cultures. Cytocentrifuge preparations of media of specimens cultured in RT disclosed, though in decreasing numbers, various hematopoietic cells for periods exceeding one month. Hematopoietic cells shed from specimens cultured in the SS system were retained in the culture tubes; cells of the myelocytic series predominated for the first two weeks while an increasing number of monocytes and macrophages appeared in the media of of older cultures. Histologic examination of cultured explants disclosed preservation of the marrow architecture and the persistence of hematopoietic cells. Specimens cultured in RT tubes tended to be less cellular than similar cultures placed in dialysis bags or as cultured in the SS system. Immunoglobulins (Ig) were released into the culture media at a constant rate throughout the period of culture. Specimens that were cultured at a controlled pH of 7.4 released 2 to more than 4 times as much Ig as similar specimens maintained at a pH level of 7.1. There were no definitive differences in Ig levels in the cultures maintained at comparable pH levels and overlaid with various CO2 concentrations, i.e. 2%, 5%, 10% similarly, no differences in Ig levels were found in specimens cultured in media containing fetal bovine sera as opposed to horse sera.

Bone Marrow↗
PubMed1976

Controlled environment treatment (CET) for patients with below-knee amputations.

This paper describes a new approach to early postsurgical wound management of the patient with a below-knee amputation. The method involves using the Controlled Environment Treatment (CET) machine, which wasdeveloped in England. A brief explanation of the components of the machine and its capabilities are listed. Ambient pressure, temperature, sterility, and humidity are easily controllable; advantages and disadvantages of this device over immediate post-operative plaster and conventional dressings as they relate both to wound environment and to physical therapy are mentioned. The early postsurgical therapy program used at Prosthetics Research Study is outlined.

Air Pressure↗
PubMed1976

Controlled environment culture of bone marrow explants from human myeloma.

Bone marrow biopsy specimens from patients with myeloma were cultured in either 1 of 2 thin-film culture systems, a controlled environment steady state system or a rocker tube configuration of the system, for periods up to 42 days. Both functional and morphological characteristics of the myeloma cells were well-maintained in these systems. Cytocentrifuge preparations of the culture media disclosed hematopoietic cells that included from 5% to almost 100% plasma cells. Histological examination of the cultured specimens disclosed infiltration of the marrow with myeloma cells. Myeloma proteins were released at a steady rate throughout the period of culture after the 1st 4 days. Bone-resorbing activity was demonstrated in the culture media in 7 of 9 myeloma culture media and was well maintained, particularly during the 1st week of culture. This activity was associated with severe osteolytic lesions in the donor patient and marked infiltration of the cultured specimen by myeloma cells. The potential use of these organ culture systems for the further definitive identification of the factor responsible for bone destruction in myeloma is discussed.

Bone Marrow↗
PubMed1992

Controlling allergies by controlling environment. A big help for your patients.

Control of the environment is a cost-effective method of limiting allergic reactions in susceptible people. For physicians working with allergic patients, this approach involves guiding the patient and family in ridding their home and surroundings of allergens and irritants. Dr. Klein discusses the environmental-control protocol, particularly in regard to dust mites, mold, pollen, and pets.

Air Conditioning↗
PubMed1986

Influence of body weight and number of inseminations on fertility of progestogen-treated ewe lambs raised in controlled environments.

The influence of body weight at breeding on reproductive response to one and two artificial inseminations (AI) of fresh extended semen was assessed in 195 crossbred ewe lambs selected for early breeding and compared with 159 adult ewes, all housed indoors in a controlled environment. In six trials, ewe lambs and adult ewes in progestogen-induced estrus were inseminated 55 to 57 h after sponge removal. One-half of the lambs and one-fourth of the adults received a second insemination at 60 h. Resultant reproductive performance of both groups indicated no advantage in a double insemination. Overall fertility, litter size and fecundity after one and two inseminations were 33%, 1.7 and .6 for ewe lambs and 68%, 2.4 and 1.6 for adult ewes, respectively. Embryonic mortality after the first 2 wk of pregnancy was estimated at 24% for ewe lambs and 9% for adults. The influence of body weight was analyzed by grouping the ewe lambs according to body weight at breeding. The lambs in group 1 weighed 30 to 35 kg; group 2, 36 to 40 kg; group 3, 41 to 45 kg and group 4, 46 to 50 kg. The proportion of ewes lambing in groups 1, 2, 3 and 4 was 16, 34, 39 and 48%, respectively. Corresponding litter sizes were 1.4, 1.6, 1.8 and 2.0. Fecundity increased (P less than 01) from .2 in group 1 to 1.0 in group 4. The results indicate that even when ewe lambs are bred by AI (eliminating a ram behavioral problem), sheep with heavier body weights produce more lambs per ewe bred.

Animals↗
PubMed1992

Health visiting: action research in a controlled environment.

The nature of health visiting is discussed. It operates in a radically different way from any of the curative services. Research into the effectiveness of health visiting must therefore take into account the many differences in context, in professional goals and in the nature of the interaction between health visitors and their "clients", compared with the work of the curative professions within their more controlled and controlling environments. The evaluation of one large scale health visitor intervention study is used here to highlight these differences. Health visiting research needs to free itself from the attempts by some to apply the laboratory model of evaluation, if it is to develop a corpus of "action research" thinking which reflects its more human and developmental characteristics.

Child↗
PubMed1975

Conversations with a chimpanzee in a computer-controlled environment.

The linguistic-type skills of a young chimpanzee (Pan) acquired in a computer-controlled language-training situation are reviewed. Those skills include facile acquisition of vocabulary, object naming, color naming, appropriate use of "yes" and "no" in response to certain questions, and conversation. In conversations the subject has formulated novel sentences and without special training has asked that objects be named, whereupon requests were made that they be given to her. These findings are interpreted in terms of how enriched environments can serve to bring forth novel communication skills in the chimpanzee, which is otherwise alinguistic; how the challenge of the environment can serve to limit manifest intelligence; and how a cognitive, rather than the traditional stimulus-response, framework is required for understanding the communication skills and psychological processes of the chimpanzee.

Animals↗
PubMed1980

Air movement and heat loss from sheep. III. Components of insulation in a controlled environment.

The rate of sensible heat loss from a Clun Forest ewe was studied at several fleece depths in a temperature-controlled chamber. A simple resistance analogue was used to describe the heat flow from different body regions. Heat loss from the trunk depends largely on the mean fleece depth l. The fleece resistance was about 1.5 s cm-1 per centimetre depth. Heat transfer through the fleece was accounted for by molecular conduction, thermal radiation and free convection. The fleece conductivity -kb attributed to free convection depends on the mean temperature difference (-Tst---Tct) across the fleece according to the relation -kb = 8.0 (-Tst---Tct)0.53. Estimates of the sensible heat flux from the trunk at environmental temperatures, Ta, between 0 and 30 degrees C range from about 8 W (l = 7.0 cm, Ta = 30 degrees C) to about 160 W (l = 0.1 cm, Ta = 0 degrees C). In contrast, the sensible heat loss from the legs depends mainly on the local tissue resistance. For environmental temperatures between 0 and 30 degrees C, the calculated tissue resistance for this region of the body varied from about 8 to 1 s cm-1. The corresponding heat loss from the legs was between 10 and 20 W, compared with between 3 and 7 W from the head. The fastest heat loss from the legs occurred at an environmental temperature of about 12 degrees C. Although the proportion of the heat loss from the extremities depends on environmental temperature, the total heat loss (sensible or latent) was closely related to the mean skin temperature of the trunk.

Air Movements↗
PubMed1980

A monogamous system of breeding chimpanzees in a controlled environment.

The management and reproductive performance of a chimpanzee colony is discussed. Short-term monogamous breedings, arranged at the estimated time of ovulation, as determined by the cyclical changes in sex skin tumescence and by a new immunological test for the preovulatory peak in urinary LH excretion, are planned according to blood group and social compatibility. Progress of gestation is monitored weekly by the "NICHD subhuman primate pregnancy test" and by prenatal clinical examinations in the last trimester. Fertility of individual animals, and of the colony as a whole, is reflected in the number of cycles of breeding required for conception. The indoor system of single caging of adults and the special system of animal waste collection offers the ability to completely control and manipulate the animals for efficient breeding, for clinical health care, and for implementation of scientific protocols.

Animals↗
PubMed1992

Effects of transcutaneous monitor electrode heat on skin servo-controlled environments.

This study tested the hypotheses that (1) the heat generated by a transcutaneous monitor electrode is sufficient to decrease skin servo-controlled radiant warmer heat output when it is positioned next to the operating skin servo-thermistor, and (2) the decrease in radiant warmer heat output is enough to lower body temperatures or cause a heat-conserving response in a baby. Seventeen newborns less than or equal to 5 days old, gestational age 29 to 40 weeks, cared for under radiant warmers were studied before and for 30 minutes after juxtaposition of the transcutaneous monitor electrode and the skin servo-controlled thermistor. Mean radiant warmer heat output, measured as watt-hours/5 minute periods, decreased for the first 15 minutes after movement, mainly in the infants cared for under an older model radiant warmer. Mean skin temperature and foot temperature decreased, and esophageal-foot temperature gradient increased for those under the older model radiant warmer. Despite differences in the gestational age of the infants under the older compared with the newer model radiant warmer, multiple regression analysis indicated a significant effect of the model of radiant warmer on the results. Many factors can influence the proper functioning of servo-controlled heating systems, including the type of electronic logic and extraneous sources of heat. These factors require more study, and should be considered in the evaluation of thermal control problems.

Body Temperature↗
PubMed1971

Growth and metabolism of L cells in a chemically defined medium in a controlled environment culture system. I. Effects of O2 tension on L-cell cultures.

Six water-jacketed 500-ml Bellco spinner flasks were equipped to monitor and control environmental variables to study their effects on the growth and metabolism of mammalian cells. Studies with automated control of pO(2) levels of l-cell cultures, grown at pH 6.9 +/- 0.1, showed that dissolved O(2) tensions of ca. 9% were optimal for cell growth. At pO(2) values of 5 and 20%, maximum cell yields as well as growth rates were reduced by approximately 20%. Peak yields of L-cell cultures exceeded 5 x 10(6) cells/ml when grown for 4 days without medium renewal from inocula of ca. 10(6) cells/ml in a defined medium sparged with 5% CO(2) and maintained at 9% dissolved O(2) tension. The redox potentials of L-cell cultures reflected the pO(2) levels in the medium and ranged from -45 to +160 mv (versus calomel reference) for O(2) values ranging from 2 to 20% dissolved oxygen tension. Increased utilization of glucose per cell occurred in the presence of increased pO(2), whereas minimal accumulation of ammonia occurred with a pO(2) value maintained at 9%.

Ammonia↗
PubMed1978

Separation testing of hemodialysis shunts using dynamic and static forces in a controlled environment.

Analytical methods are presented for determining the longitudinal dynamic and static forces needed to overcome the transverse frictional forces and effect the separation of hemodialysis shunt connections under controlled environmental conditions. Results for different types of shunts and their associated connectors are reported along with the factors that affect the separation force and separation times.

Biomedical Engineering↗
PubMed1975

[Induction of sexual maturation and egg-laying in the prawn Penaeus japonicus Bate in a controlled environment].

Studies on the endocrine mechanisms which regulate the reproduction processes in the prawn Penaeus japonicus Bate led us to investigate the role of temperature and light; these parameters probably affect the "biological clock" controlling these phenomena. Complete sexual maturation was achieved within a three month period. During the next three months, 72 spawnings from a population of 60 one and two year old females were observed corresponding to 960,000 nauplii.

Animals↗
PubMed1991

The cellular environment controls the expression of engrailed-like protein in the cranial neuroepithelium of quail-chick chimeric embryos.

We have previously shown that one of two chicken engrailed-like genes, chick En-2, is expressed in a restricted region of the early chick embryo brain: the mes/metencephalon (Gardner et al. 1988). In this study, we examine the role of the cellular environment in regulation of engrailed-like (En) protein expression in quail-chick chimeric embryos. Two types of transplant surgery were performed at the 9-15 somite stage to produce chimeric embryos. In the first, the mid-mesencephalic vesicle or caudal mesencephalic vesicle alar plate (which is En protein-positive) was transplanted from a quail embryo into an En protein-negative region of chick neuroepithelium, the prosencephalon (mMP and cMP grafts, respectively). In the second reciprocal surgery, prosencephalic alar plate which is En protein-negative, was transplanted into the En protein-positive mesencephalic vesicle (PM grafts). A polyclonal antiserum, alpha Enhb-1, which recognizes chick En proteins (Davis et al. 1991) was used to identify En-positive cells 48 h after surgery. In mMP embryos, 71% of integrated grafts had lost En expression (n = 17). In contrast, in cMP grafts, 93% of integrated grafts continued to stain with the antiserum (n = 14). In addition, in 86% of these embryos, the graft induced adjacent chick host diencephalic cells to become En protein-positive as well. All PM grafts contained aEnhb-1-positive cells; such cells never expressed this protein in their normal environment. These early changes in En protein expression correlate well with the morphological changes observed in similar graft surgeries assayed later in development. Thus, our results are consistent with the hypothesis that En genes play a role in the regionalization of the early cranial neuroepithelium.

Animals↗