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PubMed1985

The effect of leakage on the insulation provided by immersion-protection clothing.

The effect of controlled, incremental water leakage on the thermal insulation provided by three immersion-protection assemblies has been measured using a thermal manikin. The results show an average loss of 30% of the initial insulation for a leak of 500 g, 40% for a leak of 1000 g, and nearly 60% for a leak of 3000 g. The assemblies differed only in the thermal insulation layer which consisted of: A. A single thickness of wool (initial immersed insulation 0.63 clo) B. A double thickness of wool (initial immersed insulation 0.79 clo) and C. A layer of polypropylene batting between nylon covers (initial immersed insulation 0.76 clo). Differences between the assemblies in loss of insulation with leakage were small and no evidence was found to support claims that the insulating properties of polypropylene are more resistant to wetting than those of wool. It is considered that the substantial loss of insulation even with small leaks makes it essential that tests of the water-excluding performance of immersion suits are undertaken in realistic conditions rather than in calm water.

Body Temperature Regulation↗
PubMedDate not supplied

Precipitating antibodies in sera of normal blood donors against some antigens related to type III allergy, detected by counterimmunoelectrophoresis.

Precipitating antibodies against five antigens, staphylococcus aureus, candida albicans, cotton wool dust, house dust and tetanus toxoid, related to type III allergy (Arthus reaction) were estimated in 100 sera of normal blood donors by the counterimmunoelectrophoresis technique. The three antigens staphylococcus aureus, candida and cotton wool dust exhibited rather high titres of precipitins in sera of normal blood donors, whereas nearly 80% of the sera yielded no precipitins against house dust and tetanus toxoid. For diagnostic purposes the borderline titres were estimated as follows: 1:8 for staphylococcus aureus, 1:16 for candida albicans and 1:8 for cotton wool dust. Even low titres with the house dust antigen indicated a pathogenic situation.

Allergens↗
PubMed1983

Activation of nonspecific killer cells by interleukin 2-containing supernatants.

In the absence of specific antigen stimulation, nonspecific killer cells were induced by culturing C57BL/6 lymph node or spleen cells with interleukin 2-containing supernatants. These supernatants were obtained from stimulation of either rat spleen cells with concanavalin A or a variant of the T cell lymphoma, EL4 (H-2b) with phorbol myristic acetate. The ability of the EL4 supernatant to induce nonspecific killer cells was abrogated by absorption with an interleukin 2-dependent T cell line or by concanavalin A-stimulated spleen cell blasts, but not by lipopolysaccharide-stimulated spleen cell blasts or by a non-interleukin 2-producing EL4 line. Partially purified interleukin 2 from EL4 supernatants could also support nonspecific killer cell induction. The induction of cytolytic cells by interleukin 2 is sensitive to gamma-irradiation and has a D omicron of 120 rad. The nonspecific killer cells induced are likely cytotoxic T lymphocytes; the majority of the precursor and effector cells bear the Thy-1 alloantigen marker. These nonspecific killer cells killed a broad spectrum of target cells, including concanavalin A- and lipopolysaccharide-induced splenic blasts of syngeneic or allogeneic mice, a syngeneic tumor, and a cloned allogeneic cytotoxic T cell line. The frequency of precursors for nonspecific killer cells in C57BL/6 lymph node and spleen cells are 1/7000 and 1/12,000, respectively. Clonal analyses revealed that these nonspecific killers exhibit heterogeneity with respect to their target cell specificities. The induction of nonspecific killers by interleukin 2-containing supernatants is partially dependent on nylon wool-adherent cells; in antigen-stimulated cultures the most specific killer cells were obtained from cultures in which nylon wool-nonadherent lymph node responder cells were stimulated with nylon wool-nonadherent allogeneic splenic stimulator cells that were treated with anti-Thy-1 antibody and complement. The relevance of these findings with respect to the frequencies and fine specificities of cytotoxic T lymphocytes generated in interleukin 2-supplemented cultures is discussed.

Animals↗
PubMed1984

Monoclonal antibody studies of alpha-keratin low-sulfur proteins.

Monoclonal antibodies to the two families of low-sulfur proteins from wool were produced. Selection was applied to identify those hybridomas secreting antibody that was effective in the Electro-blot system. The specificities of eight different monoclonal antibodies were investigated by their binding to alpha-keratin low-sulfur proteins which had been subjected to electrophoresis from wool, goat hair, porcupine quill, rat hair and echidna quill, using the Electro-blot procedure. Considerable cross-reactivity was found both within the low-sulfur protein components of individual keratins from a particular species, and also between the keratins of the different species. Some antibodies were found to bind selectively to components of one family of low-sulfur proteins in wool, while others recognized determinants in both families, indicating some homology between the two families.

Animals↗
PubMed1984

Characterization of two different Ly-1+ T cell populations that mediate delayed-type hypersensitivity.

This paper describes two functionally different T cell populations that mediate delayed-type hypersensitivity (DTH) reactions in contact-sensitized mice. Both of these T cells are Ly-1+, Qa-2-, and Vicia villosa lectin nonadherent. One of these T cell subpopulations is responsible for the classical 24- to 48-hr component of DTH reactions, is induced 3 to 4 days after immunization, is H-2 restricted, is sensitive to irradiation and to antigen-specific T cell-derived suppressor factors, and is found in nylon wool-nonadherent as well as nylon wool-adherent populations. In contrast, the T cell population that is responsible, via an antigen-specific T cell factor, for a recently described early component of DTH, which is an obligatory initial step for expression of DTH, is induced within 24 hr after immunization, requires much less antigen for immunization, is not H-2 restricted, is not sensitive to irradiation nor to T suppressor factors, and is found exclusively in the nylon wool-nonadherent fraction. These results support a new formulation of DTH. According to this formulation, Ly-1+ T cells produce an antigen-specific, tissue-sensitizing, mast cell-activating factor, and via this factor induce the early component of DTH, which is an obligatory first step in which local antigen challenge induces increased local vascular permeability. This required opening of gaps between endothelial cells is due to T cell factor-dependent release of the vasoactive amine serotonin from cells such as mast cells. This first step allows the second, H-2-restricted, Ly-1+ T cell population to enter the reaction site, and to then be triggered by antigen to release lymphokines that attract the subsequent influx of blood-borne, bone marrow-derived leukocytes to constitute the classical delayed-in-time component of DTH reactions.

Animals↗
PubMed1983

Generation of alloreactive cytotoxic T lymphocytes: evidence for a differentiation factor distinct from IL 2.

In this report we provide evidence that the generation of cytotoxic T lymphocytes (CTL) involves a differentiation signal in addition to a proliferative signal, and that the differentiation signal is mediated by a factor distinct from interleukin 2 (IL 2). Generation of CTL from nylon wool-nonadherent splenocytes stimulated by heat-treated thymocytes did not correlate with the addition of IL 2-containing supernatants to this factor-dependent bioassay. IL 2 from two different sources and prepared by different methods (purified IL 2 from the LBRM33 cell line and partially purified IL 2 from the EL4 cell line) was not sufficient to generate a cytotoxic response in the bioassay. The inability of IL 2 to generate a cytotoxic response was not due to the use of heat-treated stimulator cells because similar results were obtained with UV-treated cells. As we previously reported, supernatant fluids containing a differentiation/activation factor did generate CTL from nylon wool-nonadherent splenocytes. Supernatant fluid from co-cultures of activated T cells and M phi as well as from cultures of activated M phi contained this CTL helper factor; however, only the former supernatant contained IL 2 activity. These results suggest a factor distinct from IL 2 is providing a differentiation/activation signal that is necessary for CTL development. Although IL 2 was not effective at generating CTL from nylon wool-nonadherent splenocytes, it was capable in some, but not all, experiments of generating a cytotoxic response from unseparated splenocytes. The ability of IL 2 to induce a cytotoxic response from unseparated splenocytes appeared to correlate with the presence of a weak background response seen when unseparated cells were used as responder cells.

Animals↗
PubMed1980

Influence of plasma factors and drugs on in vitro leukocyte adhesiveness.

Leukocyte adhesiveness was studied by measuring the retention of leukocytes in glass bead columns after the passage of heparinized whole blood or leukocyte suspensions. Leukocytes adhered readily to glass beads and independently of divalent cations when proteins were absent. Addition of plasma inhibited leukocyte adherence which became increasingly dependent on divalent cations. In conflict with results reported from nylon wool column experiments, we could not demonstrate a leukocyte adherence augmenting effect of zymosan activated plasma or plasma from patients with inflammatory diseases or patients undergoing hemodialysis. Ethanol and lidocaine gave a dose response inhibition of leukocyte adherence. The conflicting results obtained with the nylon wool and the glass head column techniques in conditions with "augmented adherence" may be due to retention of leukocyte aggregates in the nylon wool columns.

Blood Proteins↗
PubMed1980

Mouse spleen cell populations involved in the mitogenic response to protein A.

In this paper, we examined the cellular components involved in the mitogenic response of mouse spleen cells to protein A. The mitogenic response was almost abrogated by the removal of macrophages. The abrogated response could be restored by the addition of peritoneal exudate macrophages from syngeneic mice. The reconstitution experiments were carried out for studying the populations of lymphocytes responding to protein A. In these experiments, spleen cells were passed through a Sephadex G-10 column and then they were separated into nylon-wool-adherent and nonadherent cells. The nylon-wool-nonadherent cells were used as T cells. The nylon-wool-adherent cells were used as B cells after they were treated with anti-BAT and complement. These results indicated that both B and T cells responded to protein A, and T-B cell cooperation could possibly play some role in the response.

Animals↗
PubMed1981

Age-associated increase in expression of the T cell surface markers Thy-1, Lyt-1, and Lyt-2 in congenitally athymic (nu/nu) mice: analysis by flow microfluorometry.

The expression of T cell-associated surface markers by lymphoid cells from congenitally athymic (nude) mice has been quantitatively investigated using flow microfluorometry. Spleen and lymph nodes from old (greater than 6 mo) nude mice on either a C57BL/6 or BALB/c genetic background were found to contain significant numbers (5 to 13% in spleen and 15 to 24% in lymph nodes) of cells expressing Thy-1 antigen. The proportion of Thy-1 positive cells in nude spleen was dramatically increased (to 22 to 67%) after passage of the cells over nylon wool columns. In contrast to older animals, young (1- to 2-mo-old) nude mice had undetectable levels (less than 1%) of Thy-1 bearing cells in spleen and reduced levels (6%) in lymph nodes. After passage of their spleen cells over nylon wool, some Thy-1 positive cells (10%) were detectable in 2-mo-old nude mice but none were detectable at 1 mo. In addition to Thy-1, we were able to detect the T cell alloantigens Lyt-1 and Lyt-2 on nylon wool-passed spleen cells from older C57BL/6 or BALB/c nu/nu mice. In general, the proportion of Lyt-1 bearing cells in nude lymphoid populations was similar to the proportion of Thy-1 positive cells. A smaller fraction of nude cells (corresponding to 35 to 59% of the total Thy-1 positive cells) were found to express Lyt-2. Analysis of the forward light scatter distributions of nude lymphoid cells bearing either Thy-1, Lyt-1, or Lyt-2 antigens further demonstrated that an overlapping population of relatively large-size cells expressed these surface markers. These data strongly imply that at least 2 subsets of T cells (i.e., Lyt-1+2- and Lyt-1+2+) develop in older nude mice in the apparent absence of thymic influence.

Aging↗
PubMed1995

[Oxidative stress as a basic mechanism of the carcinogenic effect of man made mineral fibers on the human body].

Man made mineral fibres have been recently introduced into industry as asbestos exchangers due to their much less harmful effect on workers' health. However, in 1988 IARC classified such mineral fibres as glass wool, rock wool and slag wool as probably carcinogenic for a man. The mechanism how MMMF may induce the carcinogenic process remains still unclear. It is assumed that the involvement of these fibres in the production of free oxygenic radicals is one of the most important factors contributing to the initiation of this process by MMMF. In the condition where free oxygenic radicals are produced very fast, the cell is exposed to an oxidative stress. The DNA damage is an important consequence of the oxidative stress. New oxygenic radicals may modify DNA and lead to mutation and finally they may contribute to the occurrence of neoplastic cells. OH is an oxygenic radical which most often damages DNA. It was also indicated that MMMF contributes to the increase of the number and activity of neutrophilic granulocytes and macrophages. The appearance of MMMF fraction in granulocyte results in an increased production of free oxygenic radicals which may damage DNA of epithelial cells. Experimental studies indicate that the production of free oxygenic radicals by neutrophilic granulocytes and macrophages activated by MMMF increases under the influence of chemicals embodied in tobacco smoke. The fibres when combined with tobacco smoke enlarge the number of DNA damages. Notwithstanding the information on a possible induction of a carcinogenic process by MMMF, epidemiological studies indicate that MMMF shows much less carcinogenic hazard than asbestos fibres.

Carcinogens↗
PubMed1994

An epidemiological and toxicological evaluation of the carcinogenicity of man-made vitreous fiber, with a consideration of coexposures.

Exposure to man-made mineral (or vitreous) fiber (MMMF or MMVF) is a potential health concern in both occupational and environmental settings. Previous epidemiologic studies have reported a small increase of lung cancer among workers exposed to MMVF. Most of these studies were cohort studies and lacked information on fiber concentration, occupational coexposures, and cigarette smoking. Some of the coexposures were known human lung carcinogens and could have accounted for the small lung cancer excess. In a recently completed epidemiologic case-control study of lung cancer in MMVF workers exposed to slag wool fibers, we analyzed lung cancer risk in relation to cumulative fiber exposure (concentration and duration) and smoking history and controlled for other coexposures such as asbestos contamination. No increased lung cancer risk with exposure to slag wool fibers was found. As expected, however, we detected a strong confounding effect of smoking. The findings from this epidemiologic study were consistent with the results of recently completed toxicologic studies, which found that slag wool fibers of dimension classically associated with tumor induction ("Stanton" fibers) do not stay in the lung in sufficient quantity or time to induce tumors in animals. In this paper we emphasize the importance of confounding effects due to coexposures and provide guidelines to estimate the magnitude of potential confounding effects of coexposures such as smoking.

Animals↗
PubMed1994

Science, public policy, and stewardship.

Synthetic vitreous fibers play an important role in today's economy. Glass fibers, as an example, have found uses in more than 30,000 products that include insulations, reinforcements, fire resistant fabrics, and protective armor. Vitreous fibers also play a direct role in energy conservation. For example, in 1992, a study by Arthur D. Little found that the annual production of fiber glass batts and blowing wool used in U.S. buildings--only a fraction of the current production and use of glass wool--saved the equivalent of 33.4 million barrels of oil in 1992, avoiding the need for nearly 6800 megawatts of power. This is equivalent to 34 new 200-megawatt power plants. An ongoing commitment by the manufacturers to assure the safety of their products paralleled the growth of the vitreous fiber industry. Soon after commercialization of glass wool manufacturing in the mid-1930s, worker concerns about silica gave rise to the first study on the health of fiber glass workers (Siebert, 1942). Since that time, there have been hundreds of studies, published papers, and international reviews that have evaluated potential health effects and exposures associated with synthetic vitreous fibers.

Air Pollutants, Occupational↗
PubMed1994

Study of the retinal fiber layer in patients with acquired immunodeficiency syndrome.

A study using the monochromatic photography technique to examine the retina of a group of patients with human immunodeficiency virus (HIV) infections in different degrees of evolution and with no history of opportunistic retinal infection revealed the existence of lesions on the level of the retinal nerve fiber layer. The lesions detected included wide, slit-like defects; sector defects; and generalized diffuse atrophies. Both the sector defects and the diffuse atrophies appeared at times to be related to retinal cotton-wool exudates, but at other times they occurred in eyes with no observable retinal pathology. The results of this study can be interpreted as "in vivo" confirmations of the findings obtained by other authors in the postmortem study of optic nerves of patients with acquired immunodeficiency syndrome (AIDS), presenting a generalized degenerative process of the optic nerve with a loss of up to 40% of the axons of the retinal ganglion cells. In some cases, the results obtained in our study directly related the presence of cotton-wool exudates to the production of lesions in the retinal nerve fiber layer, whereas in other cases, the fiber lesions did not appear to be secondary to the cotton-wool exudates. Therefore, a primary lesion of the retinal ganglion cells or of the optic nerve fibers could be considered, as studies by other authors have suggested.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Problems with salivary 17-hydroxyprogesterone determinations using the Salivette device.

After introduction of the Salivette device for saliva sampling, an increase of approximately 50 ng/l was noted normal values of salivary 17-hydroxyprogesterone in our laboratory compared with previous results obtained by collection of saliva by direct spitting. To further investigate this observation systematically, 17-hydroxyprogesterone was measured in saliva of 22 healthy adults after sampling without and with the Salivette and in 15 samples of distilled water rinsed over the cotton wool swab of the Salivette. The measurements were performed with a commercially available [125I]17-hydroxyprogesterone radioimmunoassay. All steps in assay performance were exactly the same. In both series, salivary 17-hydroxyprogesterone concentrations significantly increased by 40 ng/l (p < 0.05) with use of the Salivette. The variance of the differences covered a wide range. Our results confirmed that the use of the Salivette increased salivary 17-hydroxyprogesterone values by approximately 40 ng/l. This bias is unacceptable for the establishment of reference values, as these are in the range of 20-70 ng/l in the morning. Thus, at least with our assay, the use of the Salivette is discouraged. We speculate that the cotton wool swabs contain a material. possibly derived from the biological source of the cotton wool, which cross-reacts with the antibody in the assay or affects binding affinity.

17-alpha-Hydroxyprogesterone↗
PubMed1997

[Possibility of using saliva for therapeutic monitoring of digoxin].

Digoxin in salvia and blood serum of 24 patients obtained Bemecor was determined by the method of FPIA (IMx-ABBOT). Mixed saliva was collected by three different types of Salivette (Sarstedt) given in order: normal Salivette with cotton wool swab, Slivette with polyester wool and Salivette with citric acid as a stimulator. It was found, that the correletio between the digoxin concentrations in saliva and serum and saliva/serum rations depended on the type of Salivette. The highest correlation was obtained with the Salivette with polyester wool (r = 0.892), but low concentrations of this drug in serum were good reflected in all samples of saliva, independent on kind of Salivette.

Digoxin↗
PubMed1979

Isolation of T-cells, B-cells and macrophages by a two-stage adherence procedure.

This communication describes a method to obtain enriched populations of T-cells, B-cells and macrophages. Spleen cells were initially fractionated on nylon wool columns. The nylon wool adherent fraction was removed by mechanical agitation and further separated on the basis of adherence to a coated-plastic surface in the presence of autologous serum. The tissue flask adherent population was removed with the aid of a rubber policeman. The nylon wool non-adherent and the tissue flask non-adherent and adherent fractions were characterized for the presence of cell surface markers, size, and functional activity and were identified as T-cells, B-cells and macrophages, respectively. The two-stage adherence procedure is simple to perform and does not require sophisticated equipment or expensive reagents.

Animals↗
PubMed1981

Epidermal growth factor: a critical factor in fetal maturation?

Epidermal growth factor (EGF) infused over 3-14 days into fetal sheep of 110-125 days gestation resulted in a number of morphological and endocrine changes. Striking hypertrophy of the skin, wool follicles and their accessory structures was seen, together with a reduction in the ratio of secondary to primary follicles and degenerative changes in wool fibres associated with shedding of fibres. Adrenal, thyroid, liver and kidney weights were increased while thymus weight was decreased. The increase in adrenal size resulted from cortical hypertrophy and was associated with increased cortisol secretion. Thyroid hypertrophy was accompanied by an increase in colloid stores, decreased plasma thyroxine and reverse triiodothyronine (T3) concentrations, unchanged plasma T3 and thyroid-binding globulin and raised thyrotropin (TSH) levels. Thyrotropin receptor affinity and content per gram of tissue were unchanged. Fetal and maternal plasma prolactin and growth hormone levels, and fetal plasma placental lactogen levels, were unchanged, although there was a significant rise in maternal plasma placental lactogen concentrations with high doses of EGF. Other maturational parameters such as switching from fetal to adult haemoglobin and liver glycogen content were unaffected.

Animals↗
PubMed2001

Differential responses of rat alveolar and peritoneal macrophages to man-made vitreous fibers in vitro.

Different approaches, including inhalation and intraperitoneal injection assays, have been used to assess the potential health effects of man-made vitreous fibers (MMVF). The purpose of this study was to compare the phagocytic activity and the formation of reactive oxygen species by rat alveolar macrophages (AM) and peritoneal macrophages (PM) upon exposure to MMVF10 glass wool and MMVF21 rock wool fibers. Macrophage (Mphi) phagocytosis of mineral fibers was assessed by optical videomicroscopy and computer-aided image analysis. Mphi were classified as cells not associated with fibers, cells with attached fibers, cells with incompletely phagocytized fibers (an appearance known as "frustrated phagocytosis"), and cells with completely phagocytized fibers. The production of superoxide anions by AM and PM upon incubation with MMVF10 and MMVF21 fibers was determined by the superoxide dismutase-inhibitable reduction of ferricytochrome C. PM were found to have a lower phagocytic activity than AM. A significantly higher percentage of AM than of PM underwent frustrated phagocytosis of MMVF10 and MMVF21 fibers. In line with these findings, AM generated higher levels of oxygen radicals than PM upon exposure to MMVF21 fibers. In contrast, MMVF10 fibers failed to induce the generation of reactive oxygen species by both AM and PM. Our in vitro results show that the phagocytic activity, in particular the frustrated phagocytosis of mineral fibers, was significantly lower in PM than in AM. The data support the idea that the durability and biopersistence of mineral fibers are higher in the peritoneal cavity than in the lung.

Animals↗