Unstimulated Ones Research Articles

Interleukin-1 Release by Alveolar Macrophages in Asthmatic Patients and Healthy Subjects

A thymocyte proliferative response assay was used to compare spontaneous and lipopolysaccharide (LPS)-induced interleukin-1 (IL-1) release by alveolar macrophage (AM) in asthmatic patients and normal subjects. Twelve asthmatic patients and seven nonsmoking healthy subjects underwent a bronchoalveolar lavage (BAL). All asthmatic patients had a reversible airway obstruction and 7/12 were allergic. BAL AM were separated by adherence on tissue culture plates in medium RPMI-1640 supplemented with antibiotics and fetal calf serum, and were incubated with or without 10 micrograms/ml LPS for 20 h. Free-cell supernatants were tested by C3H/HeJ mice thymocyte proliferative assay. Unstimulated AM supernatant IL-1 activity was significantly higher in asthmatic patients (mean +/- SEM: 47.8 +/- 11.9 units/10(6) AM) in comparison with healthy subjects (4.8 +/- 2.3 units/10(6) AM; p less than 0.05, Mann-Whitney U test) but did not significantly differ between allergic (42.2 +/- 15.5 units/10(6) AM) and intrinsic asthmatic patients (55.8 +/- 20.7 units/10(6) AM). For healthy subjects, IL-1 activity was significantly higher in LPS-stimulated AM supernatants (85 +/- 20 units/10(6) AM, p less than 0.05; Mann-Whitney U test) in comparison with unstimulated ones; for asthmatic patients, unstimulated and LPS-stimulated AM supernatant IL-1 activity did not significantly differ. This finding is in accordance with previous work suggesting that AM from asthmatic patients have a weak suppressive activity upon lymphocyte proliferation and emphasize the enhanced AM releasability in asthma.

Methylguanidine synthesis by active oxygen generated by stimulated human neutrophils

In previous papers, we have reported that methylguanidine (MG), a known uremic toxin, was synthesized from creatinine (Cr) by active oxygen generated not only by chemical reagents but also by isolated rat hepatocytes. In this paper, we studied whether or not active oxygen generated by stimulated human neutrophils produces MG from Cr. MG was measured after incubating 2 x 10(6) human neutrophils for 2 h in 1 ml of Hanks' balanced salt solution (pH 7.4) containing 100 mg/dl Cr at 37 degrees C after the addition of phorbol myristate acetate (PMA). MG was measured by high pressure liquid chromatography followed by reaction with 9, 10-phenanthrenequinone. MG was synthesized by the stimulated neutrophils and not by the unstimulated ones. MG synthesis reached a plateau (1.11 +/- 0.03 nmol/120 min/2 x 10(6) cells) at a concentration of 0.125 microM PMA and reached a maximum value (1.95 +/- 0.03 nmol/120 min/2 x 10(6) cells) at a concentration of 100 mg/dl Cr. MG synthesis increased depending on the concentration of neutrophils between 1 and 8 x 10(6)/ml and increased depending on the duration of incubation up to 4 h. MG synthesis was strongly inhibited by superoxide dismutase, by the scavengers of hypochloride (taurine and methionine) and by sodium azide. Catalase and the scavenger of the hydroxyl radical (dimethyl sulfoxide) inhibited MG synthesis less effectively. The effects of the scavengers of active oxygen suggest the participation of active oxygen in MG synthesis from Cr in this system. Among the active oxygen species, superoxide anion and hypochloride play an important role in this system.(ABSTRACT TRUNCATED AT 250 WORDS)

Cattle handling at abattoirs. I. The effects of rest and resting conditions before slaughter and of electrical stimulation of carcasses on carcass weight and muscle properties

In three experiments, we studied the effects of duration of rest and nature of resting conditions before slaughter and of electrical stimulation, on carcass weight, bruising and muscle properties of cattle of known age. In experiment 1, 22 Droughtmaster steers (mean liveweight 284 kg) rested for 2.5 or 26.5 h following a 125 km road journey. In experiment 2, 82 Zebu crossbred cows (mean liveweight 416 kg) rested for 4 or 52 h after a 1310 km rail journey. Those rested for 52 h were allowed to rest either peacefully (P), subjected periodically to noise and disturbances (D) or mixed with unfamiliar cows (M). In experiment 3, 68 Hereford and Simmental x Hereford cows (mean liveweight 445 kg) rested for 28 h, after a 930 km road and rail journey, and during this time were subjected to resting treatments P, D or M. All cattle had access to water until slaughter, and were slaughtered at the same abattoir. All carcasses were electrically stimulated in experiment 1, but only half those in each treatment group in experiments 2 and 3. Electrical stimulation of carcasses had a much greater effect on tenderness than did resting conditions before slaughter. The LD muscles of stimulated carcasses were more tender than those of unstimulated ones. Of the 31 cattle slaughtered after a few hours' rest, only one carcass had a high pH value 24 h post mortem. The LD muscles of cattle rested for 26.5 h were more tender than those of cattle rested for 2.5 h. Resting treatment did not consistently affect mean carcass weight, pH24, time for LD muscle to cool to 20�C or cooking loss. Noise and disturbance during the resting period appeared to be more stressful than mixing (13.6 v. 4.5% carcasses with high muscle pH 24 h post mortem in experiment 3 only). Steers rested for 26.5 h had a higher mean bruise score than those rested for only 2.5 h, but there was no effect of resting time or resting conditions on bruising in cows.

Progesterone in saliva: pitfalls and consequent implications for accuracy of the determination.

The concentration of steroid hormones in saliva is believed to reflect the concentration of free hormone in blood. Because the assay for progesterone in saliva has not been rigorously validated, we investigated some of the analytical variables involved. Saliva samples were divided into two portions. One was centrifuged and the supernate used for extraction; the other was homogenized by sonication and used as such for extraction. Progesterone concentrations in homogenized whole saliva were double or triple those in supernates. By equilibrium dialysis we established that 85% of progesterone was in the free form in supernates but only 60 to 70% in homogenized whole saliva, depending upon the phase of the cycle of the subjects. Salivary flow was stimulated by crystals of citric acid; unstimulated and stimulated saliva samples were obtained from the same person. Progesterone concentrations were significantly (p less than 0.02) higher in stimulated samples than in unstimulated ones, particularly in samples collected during the luteal phase.

Abilities of extracts of human lymphocytes to remove O6-methylguanine from DNA

O 6MeGua is a presumptive mutagenic and carcinogenic product in DNAs treated with methylating agents. The abilities of lymphocyte extracts from 34 apparently normal individuals to remove O 6MeGua from exogenous DNA have been measured. The activity in extracts is stable to freezing and so permits repeat determinations and hence high precision in the assays. The data on removal are consistent with the idea that the removal is accomplished by the transfer of a methyl group to a methyl-accepting protein and that the protein acts in a stoichiometric fashion. Extracts from lymphocytes stimulated with PHA show on the average more activity than from unstimulated ones, although some extracts show no increase as a result of PHA stimulation of cells. There are large variations in the abilities of human lymphocytes to remove O 6MeGua, but the differences are not correlated significantly with sex or age. Unstimulated lymphocytes show a bimodal distribution of removing activity, whereas stimulated ones show a predominant single peak of activity. Extracts of T lymphocytes are more proficient than those of B lymphocytes and of any other white cells. On the average the number of presumptive acceptor molecules per cell in unstimulated lymphocytes is between 14 000 and 110 000 and in stimulated lymphocytes between 40 000 and 140 000.

Starch statolith involvement in growth and geotropic reaction of apple embryo axes

Growth and geotropic reaction were studied in apple embryo axes free from starch statoliths as a result of gibberellin and temperature treatments. No positive geotropic response was observed in the starch-free, geotropically stimulated embryonal axes while unstimulated ones showed serious disturbances in the rectilinear growth. The starch statoliths are suspected to be involved in processes responsible for the symmetry of growth.

Carcass electrical stimulation and early boning of beef

Abstract In beef sides subjected to a 2 min period of high voltage (3600 V) electrical stimulation immediately after carcass dressing, rigor developed in 5 h, the ultimate pH of the meat being reached in that time. Fast chilling during this early period hardened the surface fat and aided boning, and as the meat was set in rigor, there was no risk of toughening from cold and thaw shortening in the boned-out cuts. The eating quality of the cuts was as acceptable as unstimulated ones boned at 24 h, and were further improved by aging. There was no evidence of increased microbial spoilage from boning while the meat was still warm. By boning carcasses earlier, chilling space and processing time can be saved and subsequent handling of the cartoned meat through either chilling or freezing could be automated.

Electron microscopy of human interphase nuclei. Determination of total dry mass and DNA-packing ratio.

Quantitative electron microscopy was used to analyze surface-spread, critical-point-dried human interphase nuclei and chromatin. The following information is presented: (1) Unstimulated interphase nuclei of lymphocytes from peripheral blood have a mean dry mass of 50.30×10−12 g. The mean dry mass of stimulated nuclei of lymphocytes was determined to be 59.34×10−12 g, a significant statistical difference from the unstimulated ones. (2) Mean diameter of chromatin fibers and mean fiber mass per micron were 199A±15% coefficient of variation (C.V.) and 5.95×10−16g×29% C.V., respectively. (3) A line of regression of fiber mass on fiber diameter for 83 fibers indicated that a 200-A fiber has a mass of 5.86×10−16g/μ, or almost the same as the mean fiber mass of 5.95× 10−16g/μ. (4) With the value 7×10−12g for the DNA content of an unstimulated lymphocyte nucleus, a total length of 215 cm is calculated for the DNA double helix. When this length is compared to the mean length of chromatin fiber per nucleus (7.59 cm), a ratio of 28.3 to 1 results, which is called the DNA-packing ratio. (5) This DNA-packing ratio of 28.3 is reasonably close to the packing ratio of 26.9 suggested from model calculations for the second DNA supercoil in a 200-A chromatin fiber.

Excitation and axonal flow: Autoradiographic study on motoneurons intracellularly injected with a 3H-amino acid

Tritiated glycine has been injected intracellularly into cat motoneurons by means of cross barrel iontophoresis through microelectrodes. The amino acid is incorporated into proteins in the cell body and the synthesized radioactive proteins have been localized by autoradiography. The single-cell-injection technique has several advantages over the usual intraperitoneal, intravenous or intrathecal injection, e.g. distribution of the radiochemical is strictly confined to the injected neuron; the amount of injected substance can be estimated; it is easy to investigate simultaneously electrophysiological and morphological characteristics of a defined neuron. Since the injected cell body releases radioactive proteins into the axon, the transport of these substances can be studied under various conditions. In this study the influence of antidromic stimulation has been studied. Stimulated motoneurons demonstrate higher radioactivity in their cell bodies than unstimulated ones, reflecting an increased protein synthesis. The differences are even more pronounced in the axons of stimulated cells when compared with unstimulated ones. A significant, higher amount of radioactive material — up to 100% increase as demonstrated by silver grain counting — can be seen in the axons of stimulated neurons. Although considerable differences seem to exist for the quantity of the exported proteins no significant differences have been detected for the velocity of transportation. In axons of stimulated and unstimulated neurons proteins advance toward the periphery at the same rate.