Human beta-globin gene expression in transgenic mice is enhanced by a distant DNase I hypersensitive site

Several lines of evidence suggest that erythroid-specific DNase I hypersensitive sites (HS) located far upstream of the human beta-globin gene are important in regulating beta-globin gene expression. We used the polymerase chain reaction technique to amplify and clone an 882-base-pair DNA fragment spanning one of these HS, designated HSII, which is located 54 kilobases upstream of the beta-globin gene. The cloned HSII fragment was linked to a human beta-globin gene in either the genomic (HSII-beta) or antigenomic (HSII-beta) orientation. These two constructs and a beta-globin gene alone (beta) were injected into fertilized mouse eggs, and expression was analyzed in liver and brain from day-16 transgenic fetuses. Five of 7 beta-transgenic fetuses expressed human beta-globin mRNA, but the level of expression per gene copy was low, ranging from 0.93 to 22.4% of mouse alpha-globin mRNA (average 9.9%). In contrast, 11 of 12 HSII-beta transgenic fetuses expressed beta-globin mRNA at levels per gene copy ranging from 31.3 to 336.6% of mouse alpha-globin mRNA (average 139.5%). Only three fetuses containing intact copies of the HSII-beta construct were produced. Two of three expressed human beta-globin mRNA at levels per gene copy of 179.2 and 387.1%. Expression of human beta-globin mRNA was tissue-specific in all three types of transgenic fetuses. These studies demonstrate that a small DNA fragment containing a single erythroid-specific HS can stimulate high-level human beta-globin gene expression in transgenic mice.

[Anti-inflammatory and anti-allergic action of aloperine]

Aloperine, an alkaloid isolated from Sophora alopecuroides L, showed a marked suppressive effect on the swelling of the rat's hind paw induced by injecting carrageenin, macostatin, PGE2, histamine, 5-HT, on the rat's scald oedema induced by scalding its hind paw, and on the increased permeability of capillaries caused by histamine and the leukocytic migratory response. The swelling induced by injecting carrageenin into the hind paw of adrenolectomized rats was still significantly inhibited. Noticeably, aloperine reduced the content of PGE and histamine in the exudate formed after injecting carrageenin and dextran into the rat's hind paw, and increased the stability of red cell membranes, the activity of catalase (CAT) in hepatic tissue of mice, and reduced the content of malondialdehyde (MDA) in hepatic tissue of intoxicated mice. It had no apparent effect either on the activity of superoxide dismutase (SOD) in mice serum or on the phagocytosis of the monocyte-macrophage system, or on Forssman cutaneous vasculitis and the content of immune complex in serum of rats with Arthus reaction. But it had certain inhibitory effect on the PCA reaction and significant inhibitory effect upon such allergic reaction as Arthus reaction, reversible passive Arthus reaction, the delayed hypersensitivity reaction induced by tuberculin in rats, and adjuvant arthritis.

Molecular cloning and sequencing of chicken liver fatty acid synthase cDNA

The complete amino acid sequence of chicken liver fatty acid synthase [acyl-CoA:malonyl-CoA C-acyltransferase (decarboxylating, oxoacyl- and enoyl-reducing, and thioester-hydrolyzing), EC 2.3.1.85] has been determined from the corresponding cDNA sequence. A 5.3-kilobase-pair (kbp) region of cDNA coding for chicken fatty acid synthase has been cloned and sequenced that is contiguous to the 2.3-kbp region previously sequenced [Yuan, Z., Liu, W. & Hammes, G.G. (1988) Proc. Natl. Acad. Sci. USA 85, 6328-6331]. The cDNA codes for the remaining 1677 amino acids of the previously unsequenced region of the protein. The amino acid sequence contains peptides known to be associated with the NADPH binding site of the enoylreductase active center, the acetyl/malonyltransacylase active site, the "waiting" site containing cysteine, and a pyridoxal 5'-phosphate binding site. Locations of the NADPH binding site of the beta-ketoacylreductase active site and of the dehydratase active site are proposed on the basis of protein sequence homologies to catalytic sites in other enzymes. The molecular weight of the complete polypeptide chain is 267,288. A linear functional map of the chicken fatty acid synthase derived from its primary sequence is presented.

[Dynamic changes of the plasma prekallikrein activity in patients with acute myocardial infarction]

The activity of the plasma prekallikrein was assayed by using dextran sulfate as activator and chromogenic compound substance Na-benzoyl-DL-arginine-4-nitroanilid-hydrochloride (BAPNA) as substrate. The dynamic changes of the plasma prekallikrein activity were observed in 22 patients with acute myocardial infarction (AMI) at different period. The correlation between plasma prekallikrein activity and serum CPK activity were analysed in part of the patients. The results indicate that the plasma prekallikrein activity decreased significantly in AMI, especially on the third day after onset. The decrease of plasma prekallikrein and increase of serum CPK were correlated negatively. The results indicate that the chromogenic compound substance BAPNA can be used to determine the activity of plasma prekallikrein. The kinin system was activated by certain factors in AMI, causing the decrease of plasma prekallikrein and increase of bradykinin.

[Evaluation of various parameters in the differential diagnosis of Cushing's disease and Cushing's syndrome caused by adrenal adenoma]

Evaluation of the clinical and biochemical parameters for differential diagnosis of two types of Cushing's syndrome, pituitary-dependent Cushing's disease and adrenal adenoma, was studied with analysis of the histories of 79 cases of Cushing's disease and 23 cases of adrenal adenoma. The data show that the symptoms, signs and the routine biochemical analyses were not significantly different between two groups. High-dose dexamethasone suppression test had about 90% coincidence rate in the differential diagnosis with 24-hour urine free cortisol (UFC), which was better than 24-hour urine 17-OHCS. Interestingly, low-dose dexamethasone test was highly valuable and the 24-hour urine 17-KS quite helpful in the differential diagnosis of two types of Cushing's syndrome. Serum N-POMC measurement was the most valuable among the parameters, because there was no overlap between the two groups of Cushing's syndrome.

The effects of a mandatory child restraint law on injuries requiring hospitalization

Using data on all inpatients in 16 Michigan hospitals from 1980 through 1985, the clinical effects of a mandatory child restraint law were examined. Time-series analytic techniques revealed a 36% decline in hospitalization for all injuries, with a 25% decline for head injuries, and a 20% decline for extremity injuries for children younger than 4 years. In addition, length of stay declined for children hospitalized secondary to motor vehicle crashes. This study confirms the effectiveness of the child restraint law in Michigan, previously demonstrated by analyses of police records. Current hospital databases may be able to serve as one component for the implementation of comprehensive injury surveillance systems.

Molecular cloning and sequencing of DNA complementary to chicken liver fatty acid synthase mRNA

The cDNA corresponding to 4.18 kilobases (kb) of the mRNA of chicken liver fatty acid synthase has been cloned and sequenced. The cDNA corresponds to the 3' end of the mRNA and consists of a 1.87-kb noncoding tail and a 2.31-kb region encoding 769 amino acids of the C terminus of the enzyme. The thioesterase at the C terminus, preceded by the acyl carrier protein, can be identified from known amino acid sequences. However, the identity of the enzymes N terminal to the acyl carrier protein could not be ascertained. The partial amino acid sequence of the chicken liver fatty acid synthase shows greater than 70% similarity with the rat mammary gland enzyme.

Mechanism of action of Escherichia coli heat stable enterotoxin in a human colonic cell line

Escherichia coli heat stable enterotoxin (STa) caused Cl- secretion across T84 cell monolayers in a dose-dependent manner only when applied to the apical membrane surface and not when applied to the basolateral surface. Measurement of cAMP, cGMP, and free cytosolic Ca2+ in response to STa suggested that cGMP alone mediated the Cl- secretory response. Studies utilizing blockers of the Na+,K+-ATPase pump, a Na+,K+,Cl- cotransport system, a K+ channel, and a Cl- channel suggest that all of them participate in the Cl- secretory process induced by STa. The results suggest that the Cl- secretory response induced by STa is mediated by cGMP after the enterotoxin binds to its receptor on the apical membrane. The enterotoxin, by increasing cGMP, opens a K+ channel on the basolateral membrane as well as a Cl- channel on the apical membrane. The activation of these ion exit mechanisms, together with activations of the Na+,K+,Cl- cotransporter and the Na+,K+-ATPase pump drives Cl- exit through the Cl- channel on the apical membrane.

Activity change during unfolding of bovine pancreatic ribonuclease A in guanidine

Bovine pancreatic ribonuclease A loses almost completely its activity in 2-3 M guanidine, whereas only very slight conformational changes can be detected when following its unfolding by changes in its intrinsic fluorescence at 305 nm and ultraviolet absorbance at 287 nm. Reactivation on diluting out the denaturant is a time-dependent process, indicating that the inactivation is not due to inhibition by a reversible association of the enzyme with guanidine. The kinetic method of following the substrate reaction, in the presence of the denaturant previously proposed for use in the study of rapid inactivation reactions (Tian, W.X. and Tsou, C.-L. (1982) Biochemistry 21, 1028-1032), is applied to examine the inactivation rates of this enzyme during guanidine denaturation, and these have been compared with the unfolding rates as followed by fluorescence and absorbance changes. It is shown that during the unfolding of this enzyme in guanidine, the inactivation of the enzyme occurs within the dead time of mixing in a stopped-flow apparatus and is at least several orders of magnitude faster than the unfolding reaction as detected by the optical parameters. It appears that, as in the case of creatine kinase reported previously, the active site of a small enzyme stabilized by multiple disulfide linkages, such as ribonuclease A, is also situated in a region which is much more liable to being perturbed by denaturants than is the molecule as a whole.

Kinetics of reactivation during refolding of guanidine-denatured pancreatic ribonuclease A

The method aforementioned (Liu, W. and Tsou, C.L. (1987) Biochim. Biophys. Acta 916, 455-464) for the study of the kinetics of irreversible modification of enzyme activity has been applied to the reactivation of guanidine-denatured ribonuclease A, by following the hydrolysis of cyclic CMP during refolding upon diluting a guanidine-denatured enzyme with a substrate-containing buffer. Appropriate equations have been derived to deal with the kinetics of the substrate reaction during the course of activation, while the product formed, 3'CMP, is a competitive inhibitor. When the overall process consists of multiple first-order reactions, the individual rate constants could be obtained by suitable semilogarithmic plots. Moreover, in certain cases, it can be distinguished from the shapes of the plots, whether the overall process consists of parallel or consecutive first-order reactions. The kinetics for the reactivation reaction has been compared to that for the refolding of the substrate binding site, as indicated by complex formation with the competitive inhibitor, 2'CMP, and for the refolding of the molecule as a whole. At pH 6.0 and 25 degrees C, only monophasic first-order reactions could be detected by manual mixing for both the reactivation and the refolding processes. At lower temperatures (0-10 degrees C), both processes consist of two first-order reactions. In all cases, the same rate constants have been obtained for the refolding and reactivation reactions.

Diferric transferrin reduction stimulates the Na+/H+ antiport of HeLa cells

Proton release from HeLa cells is stimulated by external oxidants for the transplasmalemma electron transport enzymes. These oxidants, such as ferricyanide and diferric transferrin, also stimulate cell growth. We now present evidence that proton release associated with the reduction of ferricyanide and diferric transferrin is through the Na+/H+ antiport. The stoichiometry of H+/e- release with diferric transferrin is over 50 to 1, which is greater than expected for oxidation of a protonated transmembrane electron carrier. Diferric transferrin induced proton release depends on external sodium and is inhibited by amiloride. Proton release is also inhibited when diferric transferrin reduction is inhibited by apotransferrin. A tightly coupled association between the redox system and the antiport is shown by sodium dependence and amiloride inhibition of diferric transferrin reduction. The results indicate a new role for ferric transferrin in growth stimulation by activation of the sodium-proton antiport.

Effect of (D-Trp6, Pro9-NEt)-GnRH on the function and ultrastructure of pituitary and testis in male rats

Groups of ten adult male Wistar rats were treated chronically with GnRH agonist for different durations. The responses of pituitary and testis to GnRH agonist were evaluated by serum and testicular testosterone, serum and pituitary LH, and testicular LH receptors. Testicular testosterone and LH receptors were decreased very significantly under our experimental regimen, irrespective of the duration of the treatment Serum testosterone levels were reduced after 10 and 15 injections, but only rats receiving 10 injections showed a significant increase in serum LH levels and decrease of pituitary LH content. The type II gonadotropes of the pars distalis of pituitary were increased in number but showed a higher degree of dilated smooth endoplasmic reticulum with few secretory granules. Many large lipid droplets appeared in the cytoplasms of the Leydig cells. Degenerative changes were observed in most seminiferous tubules following GnRH agonist treatment. Obvious abnormal acrosome and nuclear caps of some spermatids were also observed. The functional changes caused by GnRH agonist coincided with their ultrastructural appearance.

Determination of rate constants for the irreversible inhibition of acetylcholine esterase by continuously monitoring the substrate reaction in the presence of the inhibitor

The kinetics of the irreversible inhibition of acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7) by diisopropyl fluorophosphate and paraoxon have been studied by the approach of following the substrate reaction continuously in the presence of both the substrate and the inhibitor based on kinetic equations previously derived (Tsou, C.-L. (1965) Acta Biochim. Biophys. Sinica 5, 387-417). From determinations of the effects of different concentrations of substrate and the inhibitors on the apparent rate constants for the irreversible inhibition reactions it can be shown that these inhibitors are of the competitive complexing type. Both the reversible dissociation constant for the enzyme inhibitor complex and the rate constant for the subsequent phosphorylation step can be obtained from suitable plots of the experimental data.

Chloride secretory mechanism induced by prostaglandin E1 in a colonic epithelial cell line

Confluent T84 monolayers grown on permeable supports and mounted in a modified Ussing chamber secrete chloride (Cl-) in response to prostaglandin E1. The threshold stimulation was observed at 10(-9) M and a maximal effect at 10(-6) M. Unidirectional flux studies showed an increase in both serosal to mucosal and mucosal to serosal Cl- fluxes with 10(-6) M prostaglandin E1; the increase in serosal to mucosal Cl- flux exceeded the increase in mucosal to serosal flux, resulting in net Cl- secretion. Na+ transport was not affected in either direction and the changes in net Cl- flux correlated well with the changes in short circuit current. To identify the electrolyte transport pathways involved in the Cl- secretory process, the effect of prostaglandin E1 on ion fluxes was tested in the presence of putative inhibitors. Bumetanide was used as an inhibitor for the basolaterally localized Na+,K+,Cl- cotransport system whose existence and bumetanide sensitivity have been verified in earlier studies (Dharmsathaphorn et al. 1984. J. Clin. Invest. 75:462-471). Barium was used as an inhibitor for the K+ efflux pathway on the basolateral membrane whose existence and barium sensitivity were demonstrated in this study by preloading the monolayers with 86Rb+ (as a tracer for K+) and simultaneously measuring 86Rb+ efflux into both serosal and mucosal reservoirs. Both bumetanide and barium inhibited the net chloride secretion induced by prostaglandin E1 suggesting the involvement of the Na+,K+,Cl- cotransport and a K+ efflux pathways on the basolateral membrane in the Cl- secretory process. The activation of another Cl- transport pathway on the apical membrane by prostaglandin E1 was suggested by Cl- uptake studies. Our findings indicate that the prostaglandin E1-stimulated Cl- secretion, which is associated with an increase in cyclic AMP level, intimately involves (a) a bumetanide-sensitive Na+,K+,Cl- cotransport pathway that serves as a Cl- uptake step across the basolateral membrane, (b) the stimulation of a barium-sensitive K+ efflux mechanism on the basolateral membrane that most likely acts to recycle K+, and (c) the activation of a Cl- transport pathway on the apical membrane that serves as a Cl- exit pathway.

Reactivation kinetics of diethylphosphoryl acetylcholine esterase

The kinetics of reactivation of diethylphosphorylated acetylcholine esterase by pyridine-2-aldoxime methochloride has been studied using the approach of following the course of the hydrolysis of acetylcholine during the reactivation of the phosphorylated enzyme by the reactivator [Tsou, C.-L. (1965) Acta Biochem. Biophys. Sin. 5, 398-417]. Equations are derived based on the scheme of the formation of a complex between the phosphorylated enzyme and the reactivator and the rate of dissociation of this complex is not necessarily faster than the dephosphorylation and regeneration of the active enzyme. The regenerated enzyme then reacts with the substrate through an acetyl-enzyme intermediate as generally depicted. The equation obtained for product formation during the course of reactivation contains two exponential terms and this is in accord with the experimentally observed biphasic reaction. By making the assumption that the dissociation of the phosphorylated enzyme-reactivator complex is much faster than the dephosphorylation reaction, the above equation can be simplified to a form containing only one exponential term. By following the course of the reactivation reaction with the conventional approach of taking aliquots and assaying for enzyme activity recovery, it would appear likely that one would miss the initial stage of this biphasic reaction.

Alternative conformational states in the ribosome-associated 5.8S RNA

Two conformations of the 5.8S rRNA have been distinguished by gel electrophoresis. Diethyl pyrocarbonate and dimethyl sulphate reactivity were used to probe these conformational states in both the free molecule and those associated with 28S RNA or the ribosome. Both conformations could be demonstrated in each case and in every instance four residues, C50, A52, G53, C54, which were strongly reactive in the faster-migrating conformation were essentially unreactive in the slower-migrating form. These results suggest that the two conformations differ in the degree to which the tertiary structure is folded and raise the possibility that the 5.8S rRNA functions in translation by switching between alternative conformational states.

Structure of the ribosome-associated 5.8 S ribosomal RNA

The structure of the 5.8 S ribosomal RNA in rat liver ribosomes was probed by comparing dimethyl sulfate-reactive sites in whole ribosomes, 60 S subunits, the 5.8 S-28 S rRNA complex and the free 5.8 S rRNA under conditions of salt and temperature that permit protein synthesis in vitro. Differences in reactive sites between the free and both the 28 S rRNA and 60 S subunit-associated 5.8 S rRNA show that significant conformational changes occur when the molecule interacts with its cognate 28 S rRNA and as the complex is further integrated into the ribosomal structure. These results indicate that, as previously suggested by phylogenetic comparisons of the secondary structure, only the "G + C-rich" stem may remain unaltered and a universal structure is probably present only in the whole ribosome or 60 S subunit. Further comparisons with the ribosome-associated molecule indicate that while the 5.8 S rRNA may be partly localized in the ribosomal interface, four cytidylic acid residues, C56, C100, C127 and C128, remain reactive even in whole ribosomes. In contrast, the cytidylic acid residues in the 5 S rRNA are not accessible in either the 60 S subunit or the intact ribosome. The nature of the structural rearrangements and potential sites of interaction with the 28 S rRNA and ribosomal proteins are discussed.

Multiple-locus departures from panmictic equilibrium within and between village gene pools of Amerindian tribes at different stages of agglomeration

A comparative analysis of departures from multiple-locus Hardy-Weinberg equilibrium is presented for a set of four tribal Indian groups (the Yanomama, Makiritare, Wapishana and Ticuna) from the lowlands of South America. These tribes span a range of agglomeration and acculturation from the most traditional, swidden horticulturalists to frontier townspeople. The small-group social organization typical of traditional horticulturalists leads to substantial departures from tribal panmixia, as manifested by the distribution of multiple-locus genotypes both within and between villages. Within villages, the departures from single-locus Hardy-Weinberg equilibrium are small and nonsignificant, but the departures from gametic equilibrium (independence of loci) are substantial, even for the unlinked loci we have used to characterize these populations. The departures from single-locus homogeneity across villages are also substantial. One of the normal concomitants of increasing acculturation in this setting is an increase in agglomeration. As agglomeration increases, the departures from multiple-locus panmixia decrease, a process that can be very rapid. We discuss both the shifting balance theory of evolution and punctuated evolutionary rates in light of the small group social organization that must have obtained throughout most of human evolution.

Serum proteins in healthy Basenjis and Basenjis with chronic diarrhea

A serologic survey was conducted to characterize the electrophoretic patterns of serum proteins in healthy Basenji dogs (n = 137) and Basenjis with chronic diarrhea (n = 32). Serum protein electrophoresis values for Basenjis were similar to previously reported values from dogs of other breeds. Dogs with histologically confirmed lymphocytic-plasmacytic enteritis had a statistically significant (P less than 0.05) decrease in total protein, albumin, and albumin/globulin ratio. alpha 2-Globulin and gamma-globulin values were significantly increased in old dogs (9 years of age or older) with lymphocytic-plasmacytic enteritis. Although not statistically significant, gamma-globulin values were generally increased in Basenjis with lymphocytic-plasmacytic enteritis when compared with the values in age-matched clinically healthy Basenjis.

Effect of localized trauma and temporary splinting on immature skeletal muscle and mobility of the femorotibial joint in the dog

The right pelvic limbs of 2 groups of dogs were splinted in extension for 2 weeks. In 1 of these groups, the dogs were anesthetized and the distal portion of the quadriceps femoris muscle was traumatized before splinting. Two groups of control dogs were also used; neither group was splinted, but 1 group was anesthetized, and their muscles were traumatized. The range of motion of the femorotibial joint was measured in all 4 groups before splinting and 3 and 9 weeks after splinting. Types I and II muscle fiber diameters and percentages were also recorded at 3 and 9 weeks in all groups. Flexion of the femorotibial joint was limited after splinting (P less than 0.001), but less so after trauma and splinting than after splinting alone (P less than 0.0001). A reversible type I fiber atrophy occurred in most restricted muscles (P less than 0.001) and early type II fiber atrophy was seen in a few muscles after trauma and splinting (P less than 0.002). Multifocal fiber necrosis was the only irreversible change seen after 3 weeks of splinting with or without concurrent muscle trauma. Relative fiber percentages did not change appreciably during splinting or recovery.

Aryl hydrocarbon hydroxylase in human prostate

Aryl hydrocarbon hydroxylase (AHH) was present in explant cultures of human prostate obtained from surgery of benign prostatic hyperplasia and was inducible by benz[a]anthracene (BA). The induction of AHH ranged from 14- to 150-fold when compared with control values and 10-fold variation of AHH inducibility among individuals was observed. Epithelial cells grown from human prostate tissue also contained measurable AHH activity and AHH was inducible by BA and 7,12-dimethylbenz[a]anthracene (DMBA). Inducibility of AHH by BA ranged from 2- to 63-fold. The inducibility of AHH by DMBA was always less than that by BA. In cells treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), there were no changes in AHH activity. These findings support the view that the human prostate is susceptible to environmental polycyclic hydrocarbon carcinogens and that environmental and occupational factors might contribute to the etiology of human prostatic carcinoma.

Consulting to children in crisis

Although community consultation is common for psychiatrists, such activity is usually carried out on an elective rather than emergency basis. In a world troubled by community disaster situations--children are often at risk. Psychiatrists, through the use of skillful crisis consultation, can be of great help to these young people. This report describes the effort of a mental health consultation team to meet the needs of a large population of children under acute stress.

Cardiovascular dynamics after large doses of fentanyl and fentanyl plus N2O in the dog

The effects of large doses of fentanyl (0.05 to 2 mg/kg) and fentanyl plus N2O on cardiovascular dynamics were determined in 10 unpremedicated dogs breathing 100% O2. Using computer analysis of the central aortic pulsepressure curve, stroke volume (SV), cardiac output, heart rate (HR), peripheral vascular resistance (PVR), and systolic, diastolic, and mean arterial blood pressures (BP) were determined while fentanyl was being given at a rate of 0.3 to 0.44 mg/min. Fentanyl caused a dose-related decrease in HR, which was significant at 0.05 mg/kg. Cardiac output, PVR, and systolic, diastolic, and mean arterial BP were also decreased and SV increased. The latter changes became significant at 0.1 mg/kg for diastolic BP; 0.15 mg/kg for cardiac output and mean BP; 0.25 mg/kg for sv and systolic BP; and at 1.25 mg/kg for peripheral vascular resistance. Addition of N2O after fentanyl did not significantly change any parameter, although SV, cardiac output, and HR were usually increased and PVR decreased. These data demonstrate that, while large doses of fentanyl or fentanyl plus N2O do alter cardiovascular dynamics in dogs, the changes appear to be less profound than those produced by equianalgesic doses of morphine. Our findings suggest that large doses of fentanyl-O2 may be an attractive alternative to morphine-O2 anethesia in critically ill patients.