Studies on avian spinal cord chimeras. II. Immune response of the chicken host to the graft of quail tissue

A previous study described clinical and pathological manifestations observed in 49 chimeras produced by replacing a small fragment of the neural tube of a chicken embryo by a similar fragment from a Japanese quail embryo. Predominant antibodies in sera of these birds were directed against xenogeneic antigens which are devoid of organ specificity and which are present in quail tissues but absent from chicken tissues. Mixed agglutination test with quail cell monolayers detected such antibodies in sera of all chimeras tested. In most instances, positive reactions were observed already in the 4th week after hatching; they persisted in all birds throughout the observation period of up to 8 months. Some of the detected antibodies were directed against saline-nonextractable surface antigens of quail cells. Enzyme immunoassay with quail organ extracts, agglutination of quail tissue particles, and indirect immunofluorescence test with quail organ sections were positive with sera of many, but not all, chimeras. CNS-specific antibodies, apparently autoantibodies, were detected in serum samples of only one chimera, using enzyme immunoassay with extract of chicken brain and indirect immunofluorescence test with sections of chicken spinal cord. Eluates from lesional spinal cord contained antibodies to non-organ-specific quail antigens but not to CNS-specific antigens. Cerebrospinal fluids of many chimeras had antibodies to quail antigens, but no evidence for antibody formation within the CNS was obtained. Cell-mediated immunity could be demonstrated in all chimeras tested by means of lymphocyte proliferation test after stimulation by quail organ extract. It was concluded that pathological events in the studied chimeras have been most likely mediated primarily by humoral immune responses to non-organ-specific quail antigens.

Free radical yields from the homolysis of peroxynitrous acid

A recent study reports discordant results for maximal free-radical yields from the decomposition of peroxynitrous acid using different assay reagents and a puzzling decrease (to zero) of the radical yields with increasing pH. An assay method using 2,2,'azino-bis(3-ethyl-benzthiazoline sulphonate) (ABTS) has been tested using stopped-flow kinetic studies, and the results imply that the assay is satisfactory when [HOONO] much greater than [-OONO] but that reactions involving peroxynitrite anion interfere at higher pH. Evidence is presented that peroxynitrite was an interfering species in the earlier studies.

[Restriction fragment length polymorphisms of chloroplast DNA and the intergenic spacer of rRNA gene in cultivated barley of China]

A sample of 80 accessions collected from several major barley growing areas in China was assayed for restriction fragment length polymorphisms at two regions of the chloroplast DNA and the intergenic spacer of the ribosomal RNA gene (rDNA). The results showed that the spacer length was highly polymorphic and 8 spacer length variants constituting 8 phenotypes were observed in this sample. It is also clear that the spacer length variants and the phenotypes were differentially distributed in different geographical regions, probably due to adaptation of the genotypes to the local environments. We did not detect variation in the two chloroplast fragments, indicating that the variability of chloroplast DNA is low in cultivated barley.

[Isolation of desmosomes: a marker for epithelial tumors]

A simple method is reported for the isolation of desmosomes. The fresh noncornified layers of cow nose epidermis were immersed in 0.1 mol/L citric acid-sodium citrate buffer (pH 2.3, containing 0.5 mmol/L PMSF), and then treated with homogenization and discontinuous sucrose density gradient centrifugation. Desmosomes were located at the 50-56% sucrose interface. Electron microscopy revealed that the characteristic desmosome structure was well preserved, and that a few intermediate filament bundles attached to desmosome plaque were removed by the solubilizing action of the buffer. Approximate 100 mg desmosomes (dry weight) were got from 20g wet noncornified layers of epidermic tissue.

New method of one-step rainbow holography of diffuse three-dimensional objects with no slit

A new method of one-step rainbow holography of diffuse three-dimensional objects with no slit is proposed. Diffuse three-dimensional objects are translated uniformly along the direction of the y(0) axis. A coherent plane wave illuminates the objects and its propagation direction is situated on the x(0)-z(0) plane. As a result of this process, a sinc function modulating the complex amplitude distribution of the objects is produced in the back focal plane of the lens. Therefore, rainbow holography is achieved. Theoretical analysis and some experimental results are presented.

Evaluation of murine interleukin 4 (IL-4) receptor expression using anti-receptor monoclonal antibodies and S1 nuclease protection analyses

Anti-receptor antibodies have previously been used in two cytokine systems (IL-1 and TNF alpha) to identify the existence of different cytokine receptors on different cell types. In this study, we have similarly used two approaches to evaluate whether IL-4 receptors on different cell types are identical, or whether more than one species of IL-4 receptor exists. The first approach involved production of monoclonal antibodies specific for the IL-4 receptor expressed by the murine mast cell line, MC/9. Six anti-IL-4 receptor monoclonal antibodies were produced against the purified soluble extracellular domain of the recombinant IL-4 receptor derived from MC/9 cells. These antibodies were capable of binding to and specifically immunoprecipitating the soluble extracellular domain of the recombinant mast cell IL-4 receptor. Following biotinylation of the antibodies and addition of phycoerythrin-streptavidin, their binding to cell associated IL-4 receptors on MC/9 mast cells could be readily visualized by immunofluorescence. Using this approach, the anti-mast cell IL-4R antibodies were found to specifically bind IL-4 receptors expressed on a variety of other murine cell types, including T cells, B cells, macrophages, fibroblasts, and L cells. The antibodies did not bind to two human cell lines known to bind human but not murine IL-4. The intensity of staining was directly related to the number of IL-4 binding sites identified previously by receptor-ligand equilibrium binding analyses. As a second approach to evaluating potential receptor heterogeneity, we constructed S1 nuclease protection assay probes for two separate regions of the mast cell IL-4 receptor, one located in the extracellular domain and one in the intracellular domain. Subsequent S1 analyses showed that both regions are expressed by the following types of cells: T cells, B cells, macrophages, myeloid cells, L cells, and stromal cells. The two approaches used in this study therefore indicate that the same or highly similar IL-4 receptor species is expressed by a wide variety of hemopoietic and nonhemopoietic cells. Since the anti-IL-4 receptor antibodies produced in this study did not block binding of IL-4 to its receptor, we cannot exclude the possible existence of a second type of IL-4R coexpressed on the cells tested in this study, or expressed uniquely by other cell types that were not investigated.

[Morphine decreased the content of cyclic AMP in the rat spinal cord]

It has been reported that morphine or opiate-like substances (OLS) can affect the contents of cyclic AMP and/or cyclic GMP in mammalian brain, but very little is known whether similar effects also occur in spinal cord. Using RIA method, we showed that morphine significantly decreased the content of cyclic AMP in the rat spinal cord in vivo and in vitro and this effect could be completely blocked by naloxone, while the concentration of cyclic GMP in rat spinal cord is unchanged. In view of the present experiment it is suggested that the changes of cyclic AMP in the central nervous system may be partly mediated by the action of morphine.

Tunable self-reference phase conjugate interferometer

We propose a versatile self-reference phase conjugate interferometer which is based on degenerate four-wave mixing in a photorefractive crystal. A crystal of BaTiO(3) is used to store a wavefront which is compared to its displaced version at a later time. Tunable transverse and longitudinal displacements can be easily given to a wavefront. A theoretical description and experimental results of this interferometer are presented.

[The role of transmission electron microscopy played in diagnosis of knotty tumors]

Eight cases were reported in order to elucidate the important role of electron microscopy (EM) played in diagnosis of knotty tumors. The diagnosis of tumors made by light microscopy (LM) could be confirmed, corrected or eliminated with EM, and the types and histogenesis of tumors could be decided more accurately with EM than with LM. But EM has its inherent limitations, so it is emphasized that diagnosis made by EM must rest on solid basis of LM, and sometimes EM should be combined with other methods, such as histochemistry and immunohistochemistry.

Studies on antipeptic ulcer agents: the quantitative structure-activity relationship analysis of heterocyclic aldehyde N4-substituted phenyl (thio) semicarbazones

Forty-five condensation products of furan-, pyrrole- and N-methyl pyrrole-alpha-carboaldehyde with N4-3- or N4-4-substituted phenyl semicarbazones and thiosemicarbazones were designed to optimize the antiulcer activity of a previously derived lead structure, formula II. Quantitative structure-activity relationships revealed that among the series of semicarbazones, increasing hydrophobicity and the introduction of electron-donating groups into the phenyl ring raise the antiulcer activity. Generally, semicarbazones are more active than the corresponding thiosemicarbazones. The wide gulf between the activity and toxicity of two derivatives (Compounds III and IV) necessitates further investigation of their pharmacological effects.

Evidence for the generation of hydroxyl radicals from a chromium(V) intermediate isolated from the reaction of chromate with glutathione

The formation of hydroxyl radicals from a chromium(V) complex isolated from the reaction of glutathione with chromate has been demonstrated in spin trapping experiments using dimethylsulfoxide and 3,5-dibromo-4-nitrosobenzene sulfonate. Mechanisms for the formation of radicals in such systems are discussed. These results help to explain the ability of solutions containing chromate and glutathione to cause strand breaks in DNA.

[Toxic principles of Oxytropis glabra DC]

Eight alkaloids were isolated from Oxytropis glabra and identified as anagirine, thermopsine, N-methylcytisine, sparteine, baptifoline, adenine, dictamnine and ethyl allophanate respectively by spectral analysis and physicochemical methods. All these alkaloids were isolated from this genus for the first time and ethyl allophanate was found in nature for the first time.

Phase retrieval from two intensity measurements in an optical system involving nonunitary transformation

Phase retrieval from measured intensities is achieved for a practical optical system involving nonunitary transformation. We use two specific light field distributions as an example to demonstrate the iterative algorithm for phase retrieval. We chose the initial phase value to have arbitrary random distribution. For a system with different diffraction losses, we find that the retrieval can be successfully achieved even though the measured intensities contain certain random fluctuations.

Plasminogen, alpha 2-antiplasmin, and protein C decline following infusions of recombinant tissue plasminogen activator

We examined a variety of hemostatic functions in a subset of patients participating in a multicenter trial of rt-PA in the treatment of DVT. There were declines in systemic levels of plasminogen and alpha 2-antiplasmin at 24 hours following therapy. Additionally, levels of protein C antigen and protein C activity were also seen to decrease over the same time course. We propose that therapy with rt-PA has more systemic effects than previously thought and suggest that the effect on protein C may have some role in reocclusion following thrombolysis.

[Synthesis and animal experiments of ethylnitrosourea]

Ethylnitrosourea (ENU) was synthesized with raw materials such as ethylamine and sodium nitrite. The product was a yellowish powder. Its melting point, solubility and infrared absorption spectrum coincided with those reported in the literature. The result form elementary analysis for the product was almost the same as the theoretical value. The product was applied to rats by various methods. It was found that ENU was a cancerogenic compound, especially to the nervous system. More details about the animal experiments will be published in some other papers.

Circadian rhythm in c-fos protein expression in the rat adrenal cortex

The circadian variation in the expression of c-fos protein(s) in the adrenal cortex of adult rats was investigated immunocytochemically. The animals were maintained in standard laboratory facilities with a 12:12 h light:dark schedule (07.00-19.00 h) until sacrificed. The number of c-fos immunoreactive (c-fos IR) cells was statistically constant in the zona fasciculata and zona reticulata at 20.00 h and 24.00 h, and 04.00 h, but was decreased to 52% at 08.00 h and to 18% at 12.00 h, respectively, when compared to the 24.00 h value. At 16.00 h, the number of c-fos IR cells was increased again to 63% of the 24.00 h value. In the zona granulosa c-fos IR was observed only at 20.00 h and 24.00 h. Administration of dexamethasone, a potent inhibitor of ACTH release, significantly reduced the number of c-fos IR cells. As the circadian rhythm of c-fos expression in the adrenal cortex correlates to that reported for ACTH secretion from the pituitary, the results suggest that c-fos gene is involved in mediating physiological ACTH-induced responses in the adrenal cortical cells.

[Anti-angina effect of puerarin and its effect on plasma thromboxane A2 and prostacyclin]

Plasma concentrations of thromboxane B2 (TXB2) and 6-keto-prostaglandin Fl alpha(6-K-PGFl alpha), the stable nonenzymatic metabolites of TXA2 and prostacyclin were assayed in 30 patients suffering from angina pectoris before and after administration of puerarin. In addition, serum lipids and HDL were also measured at the same time. 20 healthy subjects were chosen as the control group. Two weeks before and during administration of puerarin, aspirin, calcium-antagonists, all kinds of hypotensors and drugs relieving chest pain of angina pectoris were strictly prohibited. Puerarin was intravenously given, 500 mg daily for 7 days, which was considered as a therapeutic course. Besides relieving of chest pain, decreasing of heart rate and reduction of blood pressure clinically, it was also found that plasma 6-K-PGFl alpha concentrations were significantly elevated from 38.32 +/- 15.40 to 158. 79 +/- 98.62 pg (P less than 0.01) after administration of puerarin, but there was no significantly difference between plasma TXB2 concentrations before and after administering the drug. In addition, serum HDL was apparently enhanced as compared with that before the administration of puerarin (P less than 0.01). The results indicated that puerarin has the function of anti-angina, reducing both systolic and diastolic blood pressure and diminishing myocardial oxygen consumption.

Increased numbers of extra-adrenal chromaffin cells in the abdominal paraganglia of senescent F344 rats: a possible role for the glucocorticoid receptor

The increase in numbers of extra-adrenal chromaffin cells of abdominal paraganglia in senescent F344 rats was investigated by 5-bromo-2'-deoxyuridine immunocytochemistry. A monoclonal antibody raised against 5-bromo-2'-deoxyuridine was used to react with tissue-sections of paraganglia taken from 28-month-old animals given weekly injections of the thymidine analog over a 14-week period. No immunoreactivity was detected in the extra-adrenal chromaffin cells, whereas control sections of intestinal epithelium showed abundant immunoreactivity. Also, the profile for immunoreactivity of the glucocorticoid receptor in relation to age was compared between extra-adrenal and adrenal chromaffin cells, which share cytological characteristics, but not the increase associated with senescence. In the extra-adrenal chromaffin cells, the intensity of receptor immunostaining was unchanged, while in the adrenal chromaffin cells it decreased with age. These results indicate that hypertrophy of the paraganglia in aged F344 rats is not due to the proliferation of extra-adrenal chromaffin cells. Instead, they suggest that the chromaffin cell phenotype may be induced in pre-existing cells and that the expression of the glucocorticoid receptor has an intrinsic role in this change.

Does 3,5,dibromo-4-nitrosobenzene sulphonate spin trap superoxide radicals?

Pulse radiolysis studies show that the spin trap 3,5,dibromo-4-nitrosobenzene sulphonate (I) reacts rapidly with O2.- but the product formed is very unstable. No radicals were detected in ESR studies of solutions of I after reaction with O2.- formed by gamma-radiolysis. Evidence is presented that the stable radical observed by some, but not all workers, following exposure of I to the O2.(-)-generating xanthine/xanthine oxidase system, is produced by a peroxidatic oxidation using hydrogen peroxide formed by O2-. dismutation and that formation of this radical depends on the presence of peroxidase activity in the xanthine oxidase sample employed.

Induction of c-fos protein-like immunoreactivity in the rat and hamster pineal gland after the onset of darkness

Induction of c-fos protein (FOS) after the onset of darkness was studied immunocytochemically in the rat and hamster pineal gland. The animals were kept on a 12:12 h light-dark cycle. Before the dark period no FOS staining was seen in either rat or hamster pineal cells. Five hours after the onset of darkness 342 +/- 18 pinealocytes/0.2 mm2 (mean +/- SD) displayed FOS-like immunoreactivity in the hamster pineal gland; in the rat pineal gland only 5 +/- 2 pinealocytes/0.2 mm2 showed a faint staining. Two hours later the density of FOS positive cells was decreased to 60 +/- 11/0.2 mm2 in the hamster but increased to 519 +/- 103/0.2 mm2 in the rat pineal gland. Three hours before the beginning of the light period no FOS positive cells were detected in either animal. Both the rat and hamster pineal gland showed a transient and temporally defined expression of c-fos protein in the middle of the dark period. This may be related to a more active functional state of pinealocytes, which is reflected in a peak of melatonin synthesis during the darkness.

Light and electron microscopic evidences of the presence of c-fos-like immunoreactivity in the rat adrenal cortex

The presence and localization of c-fos-like immunoreactivity in the rat adrenal cortex has been demonstrated by immunocytochemical methods at both light and electron microscopic level. C-fos-like immunoreactivity was detected in the zona fasciculata and the zona reticulata, but not in the zona glomerulosa. Ultrastructurally, all products of c-fos-like immunoreaction were localized exclusively in the regions associated with the euchromatin in the nucleus of the immunoreactive cells. Moreover, a higher density of the immunoreactive cells in the adrenal cortex of pregnant rats was found with quantitative immunocytochemistry as compared to the non-pregnant. The characteristic zonation of c-fos-like immunoreactivity in the adrenal cortex suggest that the c-fos protein is involved in the normal function of the glucocorticoid-producing cells of mammalian adrenals. The numerical increase in the immunoreactive cells in pregnant rats implies that basal expression of the c-fos-like protein may vary with the functional state of the cortical cells.

Induction of c-fos-like protein in the rat adrenal cortex by acute stress--immunocytochemical evidence

The effect of immobilization stress on the expression of c-fos protein in the adrenal cortex of adult rats was investigated immunocytochemically. After immobilization stress lasting for longer than 30 min, an enhanced c-fos-like immunoreactivity was observed in the cortical cells of the zona fasciculata and zona reticulata. Compared to unstressed controls, an about 5-fold increase in the density of the immunoreactive cells in a unit of the cortical area was seen following a 1-h immobilization. The enhanced immunoreactivity lasted for at least 3 h after 1-h immobilization and it began to diminish 5 h after the stress. Furthermore, administration of dexamethasone 2 h prior to 1-h immobilization attenuated the stress-enhanced immunostaining for the c-fos-like protein. These results suggest that an acute stress may cause a dramatic and long-persisting induction of c-fos-like protein in the cortical cells of rat adrenals. The characteristic zonal distribution of the c-fos induction in rat adrenals as well as the effect of dexamethasone suggest involvement of the pituitary adrenocorticotropic hormone (ACTH) in the induction.

Studies of safe maximal daily dietary Se-intake in a seleniferous area in China. Part II: Relation between Se-intake and the manifestation of clinical signs and certain biochemical alterations in blood and urine

Selenosis occurs in areas of Enshi county because of the high Se content of the food. Morphological changes in finger-nails were used as the main criterion for clinical diagnosis of selenosis. Pathological nails were observed to occur almost only in adults, not at all in young children and very seldom in teenagers. Symptoms of selenosis in susceptible patients were found at or above an Se-intake of 910 micrograms/d, corresponding to a blood Se level of 1.05 mg/L. There was no evidence for an increased susceptibility to dental caries due to high Se consumption, and an increase in Se-intake seems unlikely to reduce the beneficial effects of fluoride on caries. No abnormalities of liver or heart were seen by supersonic B or electrocardiographic examinations. The biochemical investigations showed that with increasing whole blood Se the ratio of plasma Se to erythrocyte Se tended to decrease. As Se-intake increases to over 750 micrograms daily, the ratio decreases to near a minimal level. Reduced glutathione in whole blood decreases within a blood Se range of 1.01 to 2.28 micrograms in the high Se area. The amount of trimethylselenonium ion excreted in urine increased with the increase of urinary Se. Cases with prolonged prothrombin time occurred as blood Se increased to a level above 1 mg/L. The white blood cell count also increased significantly. Quantitative values were obtained only for ratio of plasma-Se to erythrocyte-Se for prothrombin time and for maintenance of nail Symptoms of susceptible patients. The overall results indicated that a daily Se-intake of 750-850 micrograms [corrected] might be the marginal level of safe intake. When other variable factors are also taken into consideration a daily Se-intake of 400 micrograms [corrected] is suggested as the maximum daily safe intake. At this level of Se-intake the corresponding approximate tissue Se levels are: whole blood 0.559 mg/L, plasma 0.327 mg/L, urine excretion 173 micrograms/d, hair 3.60 mg/kg, toe-nails 4.25 mg/kg, and finger-nails 4.70 mg/kg.

Co-lamination of cholinergic amacrine cell and displaced ganglion cell dendrites in the chicken retina

Displaced ganglion cells in the chicken retina were back-labelled with Fast blue injected into the nucleus of the basal optic root, then filled under visual control with Lucifer yellow to reveal the dendritic fields of the cells. In transverse sections, the dendrites of the displaced ganglion cells formed a narrow band in the outer part of the inner plexiform layer. Counter-staining for acetylcholinesterase (AChE) activity showed that the dendrites of the displaced ganglion cells and the type I cholinergic amacrine cells co-laminated in the outer part of the inner plexiform layer.

Studies of safe maximal daily dietary selenium intake in a seleniferous area in China. I. Selenium intake and tissue selenium levels of the inhabitants

Studies of marginal safe Se-intake have been carried out in a seleniferous section of China since 1985. Three areas with low, medium and high Se levels were selected for this study. The respective average daily Se-intake (mean +/- SE) was 70.5 +/- 4.8 micrograms, 194.7 +/- 22.9 micrograms and 1438.2 +/- 76.3 micrograms for males, and 62.0 +/- 3.6 micrograms, 198.1 +/- 23.8 micrograms and 1238.5 +/- 64.6 micrograms for females (average body weight: male 55 Kg, female 53 Kg). When the increasing rate of Se-intake was compared with the corresponding tissue-Se levels it was found that the whole blood Se-level reflected more closely the physiological range of Se-intake, while at higher Se-intakes it became less sensitive than the levels in hair, finger-nail and toe-nail, which were comparable to the sensitivity of urine. It is suggested that hair, finger- and toe-nail may all act as excretory organs when excess amounts of Se are ingested. Hair- and blood-Cd are somewhat higher in residents of the high Se area, but whether they have influenced human Se-metabolism at the high level of Se-intake is not yet known. Significant correlations on log-log plots were obtained between levels of daily Se-intake and whole blood r = 0.878), breast milk (r = 0.899) and 24-h-urine (r = 0.859). Highly significant correlations on log-log plots between levels of tissue were also obtained: urine Se--plasma Se (r = 0.968), whole blood Se--hair Se (r = 0.952), fingernail Se--toenail Se (r = 0.919), hair Se--fingernail Se (r = 0.914), hair Se--toenail Se (r = 0.891), whole blood Se--toenail Se (r = 0.849) and whole blood Se--fingernail Se (r = 0.836). The highly significant correlations found between the Se-intake and the tissue-Se level, and also between the Se levels of various tissues, could possibly conveniently be used to convert the known tissue-Se level to the corresponding Se-intake. Taken together with the wide range of Se-intakes and corresponding tissue-Se levels this would provide the necessary conditions for studying the marginal and maximal safe Se-intakes in humans.

Interleukin-6 interacts with interleukin-4 and other hematopoietic growth factors to selectively enhance the growth of megakaryocytic, erythroid, myeloid, and multipotential progenitor cells

The growth-promoting activities of interleukin-6 (IL-6) in combination with different factors were assessed in bone marrow (BM) cultures prepared from normal mice and from mice treated with 5-fluorouracil (5-FU). Effects on hematopoietic colony formation with respect to number, size, and cellular composition were evaluated. In agreement with previous reports, IL-6 acts synergistically with IL-3 to stimulate increased numbers of granulocyte/macrophage (GM) and multilineage colonies in day-2 and day-4 post-5-FU BM cultures. Furthermore, day 4 but not day 2 post-5-FU BM showed enhanced GM colony formation when stimulated with IL-6 plus interleukin-4 (IL-4) or granulocyte colony-stimulating factor (G-CSF). In contrast, IL-6 did not increase the number of colonies supported by M-CSF or GM-CSF. Nevertheless IL-6 interacted with all factors, including M-CSF and GM-CSF, to stimulate an increase in colony size. Many of these myeloid colonies attained a diameter of greater than or equal to 0.5 mm, suggesting they derive from high proliferative potential cells (HPP-CFC). The response of normal and day-8 post-5-FU BM containing high numbers of more mature progenitors was also assessed. We found IL-6 enhanced colony formation by lineage-restricted megakaryocytic and erythroid progenitors in the presence of IL-3 and IL-4 plus erythropoietin (Epo), respectively. The sum of these results shows that IL-6 interacts with a variety of factors to regulate the growth of progenitor cells at different stages of lineage commitment and maturation.

Enzyme-linked immunosorbent assay for screening aflatoxin B1 in cottonseed products and mixed feed: collaborative study

A joint AOAC/IUPAC (International Union of Pure and Applied Chemistry) interlaboratory study of an enzyme-linked immunosorbent screening assay (ELISA) for aflatoxins was conducted in laboratories in Canada, France, Japan, South Africa, Switzerland, The Netherlands, Tunisia, and the United States. Twenty-eight samples of raw and roasted peanuts, corn, whole cottonseed, cottonseed meal, ammoniated cottonseed meal, and poultry feed containing various quantities of natural aflatoxins and supplemented when appropriate with aflatoxin B1 were distributed to participating laboratories for testing. The assay is based on conjugation of pure aflatoxin B1 to an enzyme and the competition between this conjugate and (free) aflatoxins in the product for aflatoxin-specific antibodies coated onto microtiter well walls. After a wash step to remove all unbound aflatoxins, a substrate, added to each well, is catalyzed from a colorless to a green solution by any bound enzyme-conjugated aflatoxin B1 present. The intensity of the color decreases as the amount of free aflatoxin B1 in the product increases. Overall correlation was good between ELISA and thin-layer chromatographic (TLC) results for cottonseed products and mixed feed. Variable results were reported for corn and peanut product samples. Although some positive samples (greater than 15 ng/g) of cottonseed products and mixed feed were reported to contain less than 15 ng/g by visual determination, a review of data for absorbance measurements showed that the contamination level was close to the greater than or equal to 15 ng/g standard and would not have been reported as negative under routine screening.(ABSTRACT TRUNCATED AT 250 WORDS)

IL-3 and stromal cell-derived factor synergistically stimulate the growth of pre-B cell lines cloned from long-term lymphoid bone marrow cultures

The addition of IL-3 to modified Whitlock-Witte long-term lymphocyte cultures was found to enhance the growth of a small but significant number of B cell precursors supported by an adherent stromal cell monolayer. Several pre-B cell lines were cloned from IL-3-treated long-term lymphocyte cultures. The growth requirements and physical properties of one representative clone, BL/3, are described. BL/3 cells were shown to be unresponsive to IL-3 except when it is used at very high concentrations. In contrast, significant growth was stimulated by stromal cell conditioned medium previously shown to contain a pre-B cell growth factor. Optimal growth of the pre-B cell clone was stimulated by stromal cell conditioned medium plus IL-3. Synergy between the stromal cell-derived factor and IL-3 occurred when IL-3 was used over a wide range of concentrations including a relatively low amount that was ineffective as a growth stimulus by itself. The finding that more than one factor is required to sustain optimal growth of some pre-B cells parallels the complex growth requirements reported for some primitive myeloid/erythroid progenitors.

IL-3 and stromal cell-derived factor synergistically stimulate the growth of pre-B cell lines cloned from long-term lymphoid bone marrow cultures

The addition of IL-3 to modified Whitlock-Witte long-term lymphocyte cultures was found to enhance the growth of a small but significant number of B cell precursors supported by an adherent stromal cell monolayer. Several pre-B cell lines were cloned from IL-3-treated long-term lymphocyte cultures. The growth requirements and physical properties of one representative clone, BL/3, are described. BL/3 cells were shown to be unresponsive to IL-3 except when it is used at very high concentrations. In contrast, significant growth was stimulated by stromal cell conditioned medium previously shown to contain a pre-B cell growth factor. Optimal growth of the pre-B cell clone was stimulated by stromal cell conditioned medium plus IL-3. Synergy between the stromal cell-derived factor and IL-3 occurred when IL-3 was used over a wide range of concentrations including a relatively low amount that was ineffective as a growth stimulus by itself. The finding that more than one factor is required to sustain optimal growth of some pre-B cells parallels the complex growth requirements reported for some primitive myeloid/erythroid progenitors.

Localization of glucocorticoid receptor messenger ribonucleic acid in hippocampus of rat brain using in situ hybridization

An in situ hybridization procedure was applied to quantify glucocorticoid receptor (GR) mRNAs in the hippocampus of rat brain. Hybridization was carried out using a radiolabeled antisense probe complementary to the rat liver GR gene. The specificity of the method was validated by showing: 1) a high cellular grain density in sections hybridized with an antisense but not a sense probe; 2) agreement between the experimental and theoretical temperature at which 50% of the hybrids melted, and 3) a high signal distribution of GR mRNA in the hippocampus, a region of brain known to preferentially concentrate steroid hormones. Within the hippocampus, however, subregional differences in hybridization densities were observed. Quantitative autoradiography indicated that the average neuronal silver grain number was highest in the pyramidal cell layers of CA2 and CA4 and lowest in those of CA1 and CA3. Also, there was a significant difference in the average grain number between all of the cell fields except for that between CA2 and CA4. These results show that contiguous but neuroanatomically distinct cell fields of the hippocampus express different levels of GR transcripts, and indicate that differential regulation of GR expression occurs in subpopulations of hippocampal neurons.

Phase-adjusted plate for a phase-adjustment focusing laser accelerator: a design approach

A design for the phase-adjusted plate for a phase-adjustment focusing laser accelerator is presented based on the general theory of the amplitude-phase retrieval problem and taking into consideration the more practical case where the incident laser beam is inclined to the axis of the cylindrical accelerator. To demonstrate this design approach, a specifically simulated design is achieved using the appropriate parameters involving the phase-adjustment focusing laser accelerator. The calculated results show that this design is successful.

Isolation and characterization of lymphokine cDNA clones encoding mouse and human IgA-enhancing factor and eosinophil colony-stimulating factor activities: relationship to interleukin 5

Conditioned medium from the Con A-treated mouse helper T-cell clone Ly1+2-/9 contains activities that enhance the production of IgA by mouse B cells and induce human cord blood cells to form eosinophil colonies. We have isolated a cDNA sequence that expresses IgA-enhancing factor and eosinophil colony-stimulating factor activities from a cDNA library prepared from activated Ly1+2-/9 cells. Based on homology with the mouse cDNA sequence, a human cDNA sequence coding for an interleukin with IgA-enhancing factor and eosinophil colony-stimulating factor activities was isolated from a cDNA library prepared from a human T-cell clone stimulated with anti-T3 antibody and phorbol 12-myristate 13-acetate. DNA sequence analyses revealed that mouse and human cDNA clones encode proteins of 133 and 134 amino acids, respectively, that are identical to cDNA clones encoding the T-cell replacing factor I and B-cell growth factor II activities. These results establish that a single cDNA clone encodes a protein that acts as a growth and differentiation factor for both B cells and eosinophils.

Optical sine transformation

The phase mask distribution of optical sine transformation (OST) has been calculated according to the optical general transformation theory. To avoid the diffraction loss of the phase mask, the optical waveguide method is used. Computation shows that the optical sine transformation is possible with only one phase mask, i.e., one-half of a cylindrical lens in the 1-D case and one-quarter of a spherical lens in the 2-D case. Experimental results agree with the theoretical prediction. Image compression by OST is also given.

Interleukin 4 (B-cell stimulatory factor 1) can enhance or antagonize the factor-dependent growth of hemopoietic progenitor cells

Our studies show that although interleukin 4 (IL-4) fails to stimulate significant colony formation by bone marrow progenitor cells, it enhances erythroid, granulocyte, macrophage, and mast-cell colony formation when used as a costimulant with erythropoietin, granulocyte colony-stimulating factor, macrophage colony-stimulating factor, and interleukin 3 (IL-3), respectively. In contrast, IL-4 suppresses IL-3-dependent colony formation by granulocyte and macrophage progenitor cells and by multipotential progenitor cells. Furthermore, it appears to inhibit the in vitro generation of colony-forming progenitor cells from immature IL-3-dependent stem cells. We also found that IL-4 inhibits stromal cell-dependent growth of bone marrow-derived pre-B cells. The ability of IL-4 to directly or indirectly regulate both positive and negative aspects of progenitor cell growth is discussed.

Control of hemopoiesis by a bone marrow stromal cell clone: lipopolysaccharide- and interleukin-1-inducible production of colony-stimulating factors

A stromal cell line, GY30, was cloned from mouse bone marrow adherent cell layers. In culture, GY30 cells sustain the production of granulocyte-macrophage progenitor cells (GM-CFU) but fail to support the survival of pluripotential stem cells (CFU-S). GY30 cells secrete two growth factor activities distinct from interleukin-3 (IL-3), IL-2, and macrophage colony-stimulating factor (M-CSF) but functionally similar to GM-CSF and G-CSF. The production of both CSFs is increased 70- to 200-fold by treating GY30 cells with lipopolysaccharide or IL-1. RNA blot analysis reveals the presence of GM-CSF and G-CSF transcripts and demonstrates that IL-1 regulates the production of both factors at the mRNA level. Further, these studies show that the GM-CSF secreted by GY30 cells is structurally similar to the GM-CSF produced by activated T cells.