Isolation and characterization of the binding sequences for the product of the Arabidopsis floral homeotic gene AGAMOUS

The Arabidopsis floral homeotic gene AGAMOUS (AG) is required for normal flower development. The deduced AG protein contains a region which shares substantial sequence similarity with the DNA-binding domains of known transcription factors, SRF (human) and MCM1 (yeast). Therefore, it is likely that AG is also a DNA-binding protein regulating transcription of floral genes. We describe here several experiments to characterize AG-DNA binding in vitro. We show that AG indeed binds a DNA sequence matching the consensus of SRF targets. Further, we have selected the AG-binding sequences from a pool of random oligonucleotides, and deduced an AG-binding consensus sequence of TT(A/T)CC(A/T)(A/t)2(T/A)NNGG(-G)(A/t)2. We have demonstrated that AG binds to the consensus region of three of the oligonucleotides by footprinting analysis. Finally, we have examined AG's relative binding affinity for different sequences, as compared to SRF, by gel mobility shift analysis. Our results indicate that AG is a sequence-specific DNA-binding protein, and that the AG-binding consensus sequence is similar to those of MCM1 and SRF.

2-Aminopurine inhibits the double-stranded RNA-dependent protein kinase both in vitro and in vivo

The autophosphorylation of interferon (IFN)-induced double-stranded RNA-dependent p68 protein kinase (PKR) and phosphorylation of the alpha-subunit of the translation initiation factor eIF-2 were inhibited by 10 mM 2-aminopurine in vitro. High concentrations of ATP overcame the inhibition. Kinetic studies indicated that 2-aminopurine is a competitive inhibitor with respect to ATP, suggesting that these two molecules bind the same site on the kinase. Treatment of HeLa cells with poly(I):poly(C) stimulated PKR autophosphorylation in vivo. The stimulated activity was inhibited by 10 mM 2-aminopurine to approximately the same extent as the in vitro inhibition.

MyoD and regulation of prostaglandin H synthase

MM14 myoblasts, in contrast to their differentiation defective variant (DD-1) cells, do not synthesize detectable levels of prostaglandins or of the initial enzyme in the pathway of prostaglandin synthesis, prostaglandin H synthase (PGHS) but do exhibit readily detectable level of PGHS mRNA (Steiner, S., et al., 1991, Exp. Cell Res. 192, 643). These findings suggest a possible relationship between the myogenic phenotype and the synthesis of prostaglandins. This relationship was examined in the current study by analysis of the effect of transfection of DD-1 cells with a MyoD expression vector (termed MyoDD-1 cells) on expression of MyoD and synthesis of prostaglandins. Proliferating MyoDD-1 cells express readily detectable levels of MyoD protein and mRNA and exhibit markedly diminished levels of PGHS protein and prostaglandins. In contrast, serum-deprived MyoDD-1 cells express little MyoD mRNA or protein and exhibit a readily detectable level of PGHS protein despite having only a slightly higher PGHS mRNA abundance compared to growing MyoDD-1 cells. These studies are consistent with the hypothesis that MyoD expression contributes to the inhibition of prostaglandin synthesis.

Intelligence function in children with acute lymphoblastic leukemia after treatment

In order to evaluate the effects of chemotherapy and central nervous system prophylaxis on the intelligence function of children with acute lymphoblastic leukemia (ALL), 147 patients were divided into 2 groups according to their different treatment regimens. Group A included 75 patients with ALL who were diagnosed and treated from 1981 to 1986. Group B included 72 ALL patients diagnosed and treated from 1988 to 1990. A control group included 73 healthy children who shared the same education and environmental background with the patients. Chinese revisions of Wechsler measures of intelligence quotient were used to estimate verbal IQ, performance IQ and total IQ in the 3 groups. American-produced Systate software was used to analyze the data. Results showed that IQ distribution, verbal IQ, performance IQ and total IQ of group A were obviously lower than those in the control group. Verbal IQ and total IQ of group B were also reduced. Significant differences of verbal IQ and performance IQ as well as total IQ were also found between groups A and B. Multiple regression analysis showed negative correlations between IQ and cranial irradiation dosage, times of intrathecal MTX and time after irradiation.

[Studies on the mechanisms of resistance to trimethoprim in Salmonella typhimurium]

The mechanisms of resistance to trimethoprim (TMP) in the clinical isolates of Salmonella typhimurium were studied. The experimental results indicated that the frequency of TMP resistance of 50 strains of Salmonella typhimurium was 76%. Seven of the resistant strains were highly resistant to TMP and four of them contained different plasmids which could transfer in the same species and between different ones, and could be eliminated with 8% of SDS. The results of comparing the activities and characteristics of dihydrofolate reductase (DHFR) in crude extracts from seven resistant strains and those from controls suggested that overproduction of the chromosomal DHFR was the resistance mechanisms in three plasmid-free strains and the levels of DHFR activity of the strains was increased during prolonged exposure to TMP in vitro. However resistance to TMP of the plasmid-containing strains resulted from production of plasmid-mediated TMP resistant type Ia DHFR and a new type DHFR which has not been reported up to now. The present work provided the theoretical basis for clinical use of TMP and attempts to suppress development and spread of duge resistance of pathogenic bacteria.

5-HT and cAMP induce the formation of coated pits and vesicles and increase the expression of clathrin light chain in sensory neurons of aplysia

In the course of studying proteins involved in long-term facilitation in Aplysia, we found that 5-HT and cAMP, a second messenger activated by 5-HT, lead to the removal of a set of N-CAM-related cell adhesion molecules (apCAMs) from the surface membrane of sensory neurons by means of receptor-mediated endocytosis. Here we describe that, as part of this coordinated program for endocytosis, 5-HT and cAMP also induce in the sensory neurons an increase in the density of coated pits and coated vesicles and an increase in the expression of the light chain of Aplysia clathrin (apClathrin). The clathrin-related endocytosis seems designed to internalize and redistribute apCAMs and other surface membrane proteins in the sensory neurons, and thus it appears to constitute one of the initial steps in the growth of new synaptic connections that accompanies long-term facilitation.

Influence of catecholestradiol on short-lived corpora lutea in beef cows

The influence of intrauterine administration of catecholestradiol (4-hydroxylated estradiol) on lifespan of the initial postpartum corpus luteum was evaluated in suckled beef cows. In experiment 1, postpartum cows (n = 23) were untreated (CONTROL) or received intrauterine infusions (0700 and 1700 hr) of either vehicle (SAL) or catecholestradiol (CATE; 4 micrograms) from day 15 to 22 (day 0 = parturition). Blood samples were collected three times weekly (day 15 to 100) and analyzed for progesterone. In experiment 2, cows received twice daily intrauterine infusions of either vehicle (n = 18), or catecholestradiol (n = 19), from day 25 +/- .5 to day 30 +/- .5. Following the final infusion, calves were temporarily weaned from all cows for 48 hr. At the end of the 48 hr weaning period, cows in each infusion group received either an i.m. injection of 1,000 IU hCG (SAL+hCG, n = 9; CATE+hCG, n = 9) or no further treatment (SAL, n = 9; CATE, n = 10). Blood samples were collected daily for 21 d following calf removal and 3 times weekly through 100 d postpartum. In both experiments, the initial postpartum elevation in peripheral progesterone concentrations was characterized as either a short (< 5 d) or extended (> 8 d) luteal phase. In experiment 1, postpartum anestrous interval (60 +/- 3.4 d) and incidence of short luteal phases (77%) were similar among CONTROL, SAL and CATE treatments. In experiment 2, luteal phases were induced within 10 d of onset of weaning in 90, 100, 56 and 60% of cows in SAL+hCG, CATE+hCG, SAL and CATE treatments, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Excess mortality among the unmarried: a case study of Japan

Recent research has demonstrated that mortality patterns by marital status in Japan are different from corresponding patterns in other industrialized countries. Most notably, the magnitude of the excess mortality experienced by single Japanese has been staggering. For example, estimates of life expectancy for the mid-1900s indicate that single Japanese men and women had life expectancies between 15 and 20 years lower than their married counterparts. In addition, gender differences among single Japanese have been smaller than elsewhere, while those among divorced persons have been unanticipatedly large; and, the excess mortality of the Japanese single population has been decreasing over the past few decades in contrast to generally increasing differentials elsewhere. In this paper, we use a variety of data sources to explore several explanations for these unique mortality patterns in Japan. Undeniably, the traditional Japanese system of arranged marriages makes the process of selecting a spouse a significant factor. Evidence from anthropological studies and attitudinal surveys indicates that marriage is likely to have been and probably continues to be more selective with regard to underlying health characteristics in Japan than in other industrialized countries. However, causal explanations related to the importance of marriage and the family in Japanese society may also be responsible for the relatively high mortality experienced by singles and by divorced men.

Altered immunoendocrine dialogue in autoimmune disease

Autoimmune diseases have a multifactorial pathogenesis including essential genetic and nonessential modulatory factors. Among the essential factors, not only should genes coding for an abnormal reactivity of the immune system be considered, but we have, in addition, provided experimental evidence for the existence of genes responsible for a susceptibility of the target organ/structure for the autoimmune attack. Only when both sets of essential genes are present does an autoimmune disease develop at all. The modulatory factors then determine the final outcome in each case. The present contribution discusses the immunomodulating role of glucocorticoid and sex steroids focussing on the Obese Strain (OS) of chickens, a model for Hashimoto thyroiditis.

Cloning of a xylanase gene from the ruminal fungus Neocallimastix patriciarum 27 and its expression in Escherichia coli

An endo-beta-1,4-xylanase gene was cloned from Neocallimastix patriciarum 27 in the bacteriophage vector lambda gtWES lambda B and was subcloned into the plasmid vectors pUC18 and pUC19 in which xylanase activity was expressed in both orientations. The xylanase was located in the periplasmic space of the host, Escherichia coli HB101. The pH and temperature optima for periplasmic xylanase activity were 6.2 and 40 degrees C, respectively, and the Km for oat spelt xylan hydrolysis was 0.89 mg.mL-1. It also exhibited hydrolytic activity on carboxymethyl cellulose that was equivalent to 28% of the activity exhibited by the enzyme on xylan. It bound to crystalline cellulose, but lacked hydrolytic activity on amorphous cellulose. SDS-PAGE followed by zymogram analysis showed active bands of 68, 58, and 51 kDa. Isoelectric focusing in gels combined with zymogram analysis showed one band of xylanase activity with a pI of 3.6.

Marriage selection and age patterns of mortality: a mathematical investigation

"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns.... We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent.... We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."

Disturbed immuno-endocrine communication via the hypothalamo-pituitary-adrenal axis in autoimmune disease

Previous studies in our laboratory demonstrated an altered immuno-endocrine feedback communication via the hypothalamo-pituitary-adrenal (HPA) axis, which may be an important modulatory factor in the development of spontaneous autoimmune thyroiditis in Obese strain (OS) chickens. These birds show a significantly lower, or even absent, increase in serum glucocorticoid levels in response to an intravenous injection of antigen or conditioned medium (CM) from mitogen-stimulated spleen cells known to contain glucocorticoid-increasing factors (GIFs), notably interleukin-1 (IL-1). The present study was aimed at investigating this feedback regulation in animal models with spontaneous systemic autoimmune diseases, such as the UCD-200 chicken, which serves as a model for human scleroderma, and various murine lupus models. In contrast to OS chickens, UCD-200 chickens displayed a nearly normal plasma corticosterone surge in response to CM, and IL-1 was again identified as the primary GIF in CM. Recombinant IL-1 also induced a drastic increase in plasma corticosterone levels in various strains of normal mice. A similar increase was observed in the bacterial lipopolysaccharide-resistant C3H/HeJ strain, thus excluding the possibility of bacterial endotoxin contamination. However, in young lupus-prone (NZB/W)F1 and MRL/MP-lpr mice, a significantly lower increase in plasma corticosterone levels was observed after injection of recombinant IL-1, suggesting a deficient immuno-endocrine communication via the HPA loop in this instance as well. Detailed studies to identify further cytokines with GIF activity in the avian and murine systems showed that both IL-6 and tumor necrosis factor-alpha could induce increased plasma corticosterone levels in mice, but not in chickens. IL-3, IL-8, transforming growth factor-beta, interferon-gamma and granulocyte-macrophage colony-stimulating factor were devoid of GIF activity in both chickens and mice.

[The effect of plasmids on the resistance of E. coli to phages]

The introduction of the ColV, I-K94 or R124 plasmid into Escherichia coli K12 resulted in resistance to certain phages. Derivatives of E. coli carrying the plasmid R124 and ColV, I-K94 were resistance to the phages T4, Mel comparing with the plasmid-free parent and the plasmid ColV, I-K94 conferred resistance to the phage Tull*. It suggested that an envelope change caused by the plasmids might be responsible for the resistance because most of the phages fell to absorb to the plasmid-bearing E. coli cells.

Treatment of 100 cases of nerve deafness with injectio radix salviae miltiorrhizae

100 cases of nerve deafness were treated with Injectio Radix Salviae Miltiorrhizae by i.v. drip, and additional drugs that promoted blood circulation were used according to symptom differentiation. Results were 28 cases cured, 45 cases improved, and 27 cases failed, for a total effective rate of 73%.

Effects of a benz[e]indene on gamma-aminobutyric acid-gated chloride currents in cultured postnatal rat hippocampal neurons

Benz[e]indenes (BIs) are tricyclic molecules that can be envisioned as steroids without an A-ring. Because certain steroids are known to alter gamma-aminobutyric acid (GABA) responses in central neurons, we examined the effects of a substituted BI resembling 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-OH-DHP) on GABA-gated chloride currents in cultured postnatal rat hippocampal neurons. The compound, BI-1, reversibly potentiated GABA currents at concentrations of > 10 nM, with an EC50 value of 0.2 microM. BI-1 increased the apparent affinity of GABA for its receptor, decreasing the GABA EC50 from 9 microM to 3 microM. BI-1 had no effect on the shape of the GABA current-voltage relationship and did not alter the GABA reversal potential. The effects of BI-1 were not altered by benzodiazepine or picrotoxin site antagonists. At concentrations up to 10 microM, where maximal effects on GABA currents were seen, BI-1 did not directly activate a membrane current. This contrasts with the effects of 3 alpha-OH-DHP, which activated chloride currents at concentrations that were subsaturating for GABA potentiation. These results suggest that the BIs may be useful for determining the mechanisms by which steroids potentiate GABA responses and directly gate chloride channels.

Ultrastructural study of cerebral arteries in Moyamoya disease

The cerebral arteries in seven cases of Moyamoya disease, demonstrated by angiography were observed by light, transmission and scanning electron microscopy. In two cases, the lumen of the terminal portion of the internal carotid artery was completely occluded by proliferated connective tissue. The characteristic pathologic change was extensive destruction of the smooth muscle cells and the elastica interna. Degeneration and necrosis of smooth muscle cells were obvious in the media. Many condensed organelles and other elements of cellular destruction were dispersed throughout the interstitium. The media was thinned. The proliferated smooth muscle cells in the intima showed the same destructive changes as in the media. The elastica interna was excessively infolded and was thickened or thinned, disrupted or disintegrated in some segments. Identical, but less severe and more localized changes were seen in three middle cerebral arteries (M2 and M5 segments) and two collateral arteries at the base of brain. These changes suggest that Moyamoya disease is a progressive disorder characterized by repeated destruction of smooth muscle cells occurRing over a long time period. The pathogenesis of these changes is discussed.

Functional changes in salivary glands of autoimmune disease-prone NOD mice

Lymphocytic infiltration of the salivary glands in autoimmune diseases results in the human condition known as xerostomia. To date, an animal model for the autoimmune development of salivary gland dysfunction has yet to be described. With the autoimmune diabetes-prone nonobese diabetic (NOD) mouse strain, salivary flow rates and total saliva protein concentration in both male and female mice showed a progressive decline in the nondiabetic and diabetic states. Submandibular gland weight decreased from control mice with the progression to onset of diabetes in both sexes, whereas the weight of the parotid gland remained unchanged. The level of saliva amylase activity, when measured relative to unit volume, decreased in nondiabetic males but increased upon onset of diabetes to control values. When expressed relative to protein concentration in saliva, amylase activity was depressed for both sets of NOD mice but was higher upon diabetes onset than in the nondiabetic animals. In females a similar pattern was observed except that amylase activity expressed relative to unit volume was not significantly depressed in either set of NOD mice. The same observations were made for glandular amylase activity. The level of epidermal growth factor (a product of the ductal cells of the submandibular gland) was reduced over 500- and 18-fold for male and female diabetic mice, respectively. Sodium dodecyl sulfate polyacrylamide gels of total saliva showed changes in mobility as well as concentration of several proteins in the NOD mice.(ABSTRACT TRUNCATED AT 250 WORDS)

[Purification, characterization and reverse cholesterol transport of human serum apolipoprotein A-IV]

In order to study the function of apoA-IV, human serum apoA-IV was isolated and purified. LDS was isolated with NaBr density gradient ultracentrifugation and then incubated with intralipid according to the method of Weinberg and Scanu. Protein complex containing apoA-IV was obtained. The apo-IV was purified from protein complex by preparative SDS-PAGE, electroelution and removal of SDS. ApoA-IV thus prepared gave a single band on SDS-PAGE with a MW of 46 kD. Amino acid composition and isoelectric focusing pI (5.27 and 5.47) of apoA-IV were similar to those reported in the literature. The effects of apoA-IV and liposome (apoA-IV: DMPC) on cholesterol efflux from hum skin fibroblast were studied. There was no significant difference (P > 0.5) between apoA-IV and control but a very significant difference (P < 0.001) between liposome (apoA-IV:DMPC) and control, suggesting that liposomes (apoA-IV:DMPC) play a role in reverse cholesterol transport. The results may offer a new approach for the prevention and treatment of atherosclerotic coronary heart disease.

Effects of l-stepholidine on synaptosomal Ca(2+)-ATPase and subcellular calmodulin in rat striatum

Our results showed that l-stepholidine (l-SPD) inhibited basal Ca(2+)-ATPase activity in rat striatal synaptosomes with an IC50 of 31.5 mumol.L-1, suggesting its interaction with Ca2+ transport. l-SPD inhibited also calmodulin (CaM)-activated basal Ca(2+)-ATPase in a concentration-dependent manner. A complete reversal of CaM activation of Ca(2+)-ATPase was observed with l-SPD 10 mumol.L-1. The activity of synaptosomal Ca(2+)-ATPase and membrane-bound CaM level were decreased in haloperidol (1 mg.kg-1.d-1, ip) and l-SPD (5, 10, and 30 mg.kg-1.d-1, ip) treated rats for 7 and 14 d, respectively. But the activity of Ca(2+)-ATPase and membrane CaM level were increased after treatment with the same of doses haloperidol and l-SPD for 21 d. During the treatments with haloperidol and l-SPD cytosolic and nuclear CaM levels were not altered. These results suggest that l-SPD may modulate the release and synthesis of dopamine (DA) and the negative feedback regulation of presynaptic DA receptors by altering Ca2+ and CaM regulating processes in the central dopaminergic nervous system.

[The toxicity of herbicide Asulam]

We conducted a series of toxicity tests and short-term mutagenic assays of Asulam and 40% (W/V) sodium Asulam. It was found that the LD50 of Asulam with acute oral toxicity was 30000 mg/kg for mice, and the LD50 of sodium Asulam for mice and rats were equal (8250 mg/kg). The cumulative coefficient of sodium Asulam in Wistar rats was 9.42. None died from sodium Asulam absorbed via skin. Negative results were obtained in Ames test, Bacillus subtilis repair test and the micronucleus test. There was no significant difference between the control group and the treated groups in the chromosomal aberration rates of spermatogonia and primary spermatocytes of mice testis. The results indicated that Asulam should be regarded as a substance of low toxicity and low accumulation. No mutagenicity was observed in our experiment.