Reconstitution of human TFIIA activity from recombinant polypeptides: a role in TFIID-mediated transcription

Human TFIIA activity is composed of three subunits (alpha, beta, gamma). Here we report the isolation of a human cDNA clone encoding the gamma-subunit and the reconstitution of TFIIA activity from recombinant polypeptides (holo-TFIIA). Protein-protein interaction analysis established that the beta and gamma subunits of TFIIA interact with the TBP component of TFIID. The alpha-subunit is recruited into the complex by association with the gamma-subunit. Functional studies indicate that recombinant TFIIA stimulates basal TFIID-dependent transcription but is without effect on TBP-dependent transcription. Our studies indicate that TFIIA not only functions by physically removing negative components present in TFIID (antirepression), as demonstrated previously, but that it can stimulate basal transcription through components of the TFIID complex. Holo-TFIIA also stimulated activation of transcription in vitro as well as in vivo in transfected HeLa cells.

The influence of induction chemotherapy dose and dose intensity on the duration of remission in acute myeloid leukemia. Australian Leukemia Study Group

The aim of this study was to assess the influence of dose and dose intensity (DI) of induction and consolidation chemotherapy on relapse rates in 264 de novo patients with acute nonlymphocytic leukemia (ANLL). Patients were randomised to receive cytosine arabinoside (ARAC) 100 mg/m2 continuous infusion for 7 days and daunorubicin (DNR) 50 mg/m2 IV day 1-3 (7-3) or the same drugs with the addition of etoposide 75 mg/m2 IV days 1-7 (7-3-7). Cox proportional hazards regression models were used throughout to identify prognostic factors, including dose delivery parameters, influencing the rate of relapse. Of 152 patients who achieved a complete remission (CR), 104 have relapsed with a median duration of CR of 15.8 months. Actual dose delivered was prospectively documented. Cox regression analysis identified the most significant prognostic factors jointly influencing duration of CR as performance status groups (p < 0.0001), percentage peripheral blasts (p = 0.0015), 7-3-7 arm (p = 0.0075), age < 40 years (p = 0.022) and induction dose ARA-C plus DNR (p = 0.029). In this analysis patients randomized to the 7-3-7 arm had an estimated 43% reduction in the relapse rate and each 10% reduction of doses ARA-C and DNR was associated with an estimated 45% increase in the relapse rate. The number of induction courses, delays in treatment and induction dose intensity did not significantly influence the duration of CR nor did any of the consolidation treatment parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

[Distribution, content and action site of leucine-enkephalin in pulmonary artery wall of rat and rabbit]

Using immunohistochemical method to investigate the distribution of peptidergic fibers in the pulmonary artery wall of SD rat, L-enkephalin immunoreactive (L-ENK ir) fibers were easily demonstrated. The contents of L-ENK in pulmonary artery of rat and rabbit measured by radioimmunoassay were respectively 439.18 +/- 30.52 and 29.9 +/- 1.4 (pg/mg of wct tissue). Contraction of superfused strips of pulmonary artery of rabbit could be evoked by parameter I electric field stimulation. The response was blocked by alpha-receptor antagonist phentolamine. Alpha 2-receptor antagonist Yohimbine enhanced the response in small doses (0.06-0.12 mumol/L), while inhibited in large (3.2 mumol/L). The contraction could also be enhanced when the artery strips were preincubated with naloxone. After the alpha-receptors were blocked with phentolamine, stronger contraction could still be evoked by parameter II electric field stimulation and the response was not affected by naloxone. L-ENK had no effect on the contraction evoked by exogenous NE. The present experiments demonstrate that enkephalin presented in the pulmonary artery wall are released by electric field stimulation. Enkephalin may reduce the release of NE from sympathetic nerve endings via opioid receptors and inhibit the contraction response.

Role of efflux pump(s) in intrinsic resistance of Pseudomonas aeruginosa: active efflux as a contributing factor to beta-lactam resistance

Wild-type strains of Pseudomonas aeruginosa are more resistant to various beta-lactam antibiotics as well as other agents than most enteric bacteria. Although resistance to compounds of earlier generations is explained by the synergism between the outer membrane barrier and the inducible beta-lactamase, it was puzzling to see significant levels of resistance to compounds that do not act as inducers or are not hydrolyzed rapidly by the chromosomally encoded enzyme. This intrinsic-resistance phenotype becomes enhanced in those strains with the so-called intrinsic carbenicillin resistance. In the accompanying paper (X.-Z. Li, D. M. Livermore, and H. Nikaido, Antimicrob. Agents Chemother. 38:1732-1741, 1994), we showed that active efflux played a role in the resistance, to various non-beta-lactam agents, of P. aeruginosa strains in general and that the efflux was enhanced in intrinsically carbenicillin-resistant strains. We show in this paper that, in comparison with the drug-hypersusceptible mutant K799/61, less benzylpenicillin was accumulated in wild-type strains of P. aeruginosa and that the accumulation levels were even lower in intrinsically carbenicillin-resistant strains. Deenergization by the addition of a proton conductor increased the accumulation level to that expected for equilibration across the cytoplasmic membrane. In intrinsically carbenicillin-resistant isolates, there was no evidence that either nonspecific or specific permeation rates of beta-lactams across the outer membrane were lowered in comparison with those of the more susceptible isolates. Furthermore, these carbenicillin-resistant isolates were previously shown to have no alteration in the level or the inducibility of beta-lactamase and in the affinity of penicillin-binding proteins. These data together suggest the involvement of an active efflux mechanism also in the resistance to beta-lactams. Hydrophilic beta-lactams with more than one charged group did not cross the cytoplasmic membrane readily. Yet one such compound, ceftriaxone, appeared to be extruded from the cells of more-resistant strains, although with this compound effects of proton conductors could not be shown. We postulate that wild-type strains of P. aeruginosa pump out such hydrophilic beta-lactams either from the periplasm or from the outer leaflet of the lipid bilayer of the cytoplasmic membrane, in a manner analogous to that hypothesized for multidrug resistance protein of human cancer cells (M.M. Gottesman and I. Pastan, Annu. Rev. Biochem. 62:385-427, 1993).

Characterization of intraocular tumors arising in transgenic mice

PURPOSE

To characterize intraocular tumors that arise by in situ transformation in the choroid-retinal pigment epithelium (RPE) in transgenic mice bearing the SV40 oncogene under the control of the mouse tyrosinase promoter.

METHODS

Tumors from TySV40 transgenic mice were characterized in vivo and in vitro by immunohistology, compound microscopy, and electron microscopy. Tumor cell lines were established and characterized for growth and metastatic potential in the eyes of nude mice.

RESULTS

On light microscopy, ocular tumors were predominantly epithelioid, although occasional clusters of spindle cells were also present. Transmission electron microscopy revealed the presence of numerous basal infoldings and abundant multilaminated basement membranes on the ocular tumors. Tumors stained with antibodies to melanoma-associated antigens, gangliosides GD2 and GD3, and the SV40 T antigen. Radiolabeled transgenic tumor cells preferentially localized in the liver after intravenous injection in normal mice. Intracamerally transplanted transgenic tumors metastasized from the eyes to the livers of nude mice.

CONCLUSIONS

In TySV40 transgenic mice, intraocular tumors develop that arise at the choroid-RPE interface, and they display morphologic and ultrastructural features consistent with RPE carcinomas. However, the transgenic tumors express melanoma-associated antigens and a propensity to metastasize to the liver, two features characteristic of uveal melanomas. The TySV40 transgenic murine tumors represent potentially useful tools for investigations into the biology and metastasis of intraocular neoplasms.

Isolation and characterization of gap junctions in the osteoblastic MC3T3-E1 cell line

Gap junctions are channels connecting cells that function in cell-to-cell communication. Gap junctions are abundant in osteoblastic cells. Membranes enriched for gap junction plaques were obtained by differential centrifugation, followed by treatment of the membranes with potassium iodide and sarkosyl before sucrose density gradient centrifugation. Electron microscopy showed that the preparation was enriched for electron-dense membranes consistent with gap junctions. Coomassie Blue staining of SDS-PAGE preparations revealed a prominent band at approximately 41 kD. Western analysis with a site-directed antibody, CT-360 (D. Laird, California Institute of Technology, Pasadena, CA), to the C-terminal portion of the rat heart connexin 43 molecule was positive in the MC3T3-E1 cell line, a phenotypic osteoblastic cell line derived from normal neonatal mouse calvariae. Western analysis using a monoclonal antibody, R5.21C, to rat liver connexin 32 was negative. Additionally, a prominent band at 59 kD was detected by CT-360 in both gap junction-enriched preparations and cell lysates. Treatment of diluted samples of gap junction-enriched preparations with sulfhydryl reducing agents in combination with detergents resulted in the enhancement and diminution of the 41 and 59 kD bands, respectively. Immunoprecipitation following [35S]methionine/[35S]cysteine labeling revealed a significant band detected at 122 kD in addition to the 41 kD band. To demonstrate functional gap junctions, transfer of lucifer yellow dye to surrounding cells was monitored after microinjection of a target cell. Between passages 10 and 25 in culture, functional cell coupling was found in approximately 70% of injected cells. Coupling was detected within 1-2 minutes after injection. Simultaneous microinjection of the CT-360 antibody with lucifer yellow resulted in the decoupling of cells. In conclusion, (1) MC3T3-E1 cells possess a 41 kD protein that is recognized by connexin 43 antibody to rat heart gap junction; (2) multimers of the MC3T3-E1 gap junctions occur in the preparation; and (3) functional coupling demonstrated by dye transfer may be regulated by region(s) in the C terminus of the connexin molecule.

Efficient anchoring of RNA polymerase in Escherichia coli during coupled transcription-translation of genes encoding integral inner membrane polypeptides

While it has been known that supercoiling of the DNA template can be induced by transcription, the mechanism and the efficiency of this process in vivo is not fully understood. We report here that transcription of genes encoding 16 S rRNA, a stable RNA species, or cytoplasmic polypeptides leads to very little or no detectable DNA supercoiling even under the optimum conditions in Escherichia coli. This indicates that hydrodynamic drag on the transcription complex (including RNA polymerase, nascent RNA, ribosomes, and nascent polypeptides) is not sufficient to anchor RNA polymerase during coupled transcription-translation. On the other hand, transcription of membrane-associated genes encoding integral inner membrane or exported periplasmic polypeptides leads to apparent DNA supercoiling. Transcription of genes encoding integral inner membrane polypeptides leads to significantly greater anchoring of RNA polymerase than does transcription of genes encoding periplasmic polypeptides. This may reflect differences in the coupling of transcription-translation with membrane association during expression of these two classes of polypeptides. Evidence is further presented to suggest that the anchoring of RNA polymerase is probably achieved through the interaction of nascent polypeptides with the cytoplasmic surface of the inner membrane during coupled transcription-translation. Moreover, transcriptions of a membrane-associated gene can, under certain circumstances, induce topological anchoring of an RNA polymerase transcribing a neighboring gene that ordinarily is not membrane-associated. Finally, the potential biological consequences of our findings are discussed.

Response of calcitonin-gene-related peptide-like immunoreactive nerve fibers of the anterior pituitary to adrenalectomy in the rat

The mammalian anterior pituitary is known to be regulated by humoral factors only, no direct neural influence having ever been discovered. Our recent studies have shown in several species that there are substantial amounts of substance P and calcitonin-gene-related peptide-like immunoreactive (CGRP-LI) nerve fibers in the anterior pituitary and that they can make synaptic contacts with secretory cells, among which corticotropes. In the present study, we investigated changes in CGRP-LI nerve fibers of the anterior pituitary after bilateral adrenalectomy in the rat. The results show that the number of CGRP-LI nerve fibers increases significantly. In parallel, they cover a wider area of the gland after the operation, suggesting a direct neural influence.

Rejection of intraocular tumors from transgenic mice by tumor-infiltrating lymphocytes

The present study examined the role of tumor infiltrating lymphocytes (TIL) in the rejection of intraocular tumors from SV40 transgenic mice. Tumor cells from an intraocular tumor arising in an SV40 transgenic FVB/N mouse were transplanted into the eyes of syngeneic FVB/N mice and the TIL isolated. TIL were assessed for direct cytolytic activity in vitro. TIL were also transferred passively to immunosuppressed FVB/N mice to determine if they could mediate intraocular tumor rejection. The role of CD4+ and CD8+ T cells in intraocular tumor rejection was evaluated by depleting the respective cell populations in FVB/N hosts prior to intraocular tumor challenge. The results showed that intraocular tumors undergoing rejection in immunocompetent syngeneic hosts became infiltrated with T cells, with the CD8+ subset predominating at the time of rejection. By contrast, athymic nude mice did not reject the intraocular tumors nor did the tumors become infiltrated with TIL. TIL displayed direct, tumor-specific cytolytic activity immediately after isolation from the tumor-containing eyes. FVB/N hosts depleted of CD4+ T cells were unable to reject their intraocular tumors. In vivo depletion of CD8+ T cells delayed, but did not prevent tumor rejection. Adoptively transferred TIL mediated swift rejection of intraocular tumors in immunoincompetent recipients. Recipients of TIL, but not recipients of normal spleen cells, acquired significant tumor-specific CTL activity that was demonstrable in vitro. The results strongly suggest, but do not prove, that TIL mediate rejection of intraocular tumors from transgenic mice by direct cytolysis. Although CD4+ T cells are necessary for tumor rejection and are capable of direct cytolysis, the predominant effector cells are CD8+ CTL.

Capacity of simian virus 40 T antigen to induce self-tolerance but not immunological privilege in the anterior chamber of the eye

Transgenic mice bearing the simian virus 40 (SV40) large T oncogene developed progressively growing intraocular tumors and displayed characteristics of immunological tolerance to SV40 T antigen. Transgenic mice failed to mount CTL responses to SV40 T antigen-bearing tumor cell lines derived from the transgenic intraocular tumors. Spleen cells from transgenic hosts were able to prevent the in vivo and in vitro generation of CTL responses by lymphocytes from normal syngeneic FVB/N mice. Adoptive transfer of spleen cells from tolerant transgenic donors temporarily inhibited the immunological rejection of SV40 T antigen-positive tumor cells transplanted to normal syngeneic FVB/N recipients. Thus, introduction of SV40 transforming sequences into the mouse germline induced tolerance to SV40 T antigen. However, in normal FVB/N mice, SV40 T antigen-bearing tumor cells failed to experience immune privilege in the anterior chamber and did not elicit systemic down-regulation of delayed-type hypersensitivity responses that characteristically occur when antigens are introduced into the anterior chamber. The results indicate that within the anterior chamber of the eye, SV40 T antigen-bearing cells are perceived by the host's immune system much differently than are other categories of antigen. Thus, SV40 T antigen effectively induces self-immunological tolerance when its gene is introduced into the host's germline but fails to experience immunological privilege in the anterior chamber of the eye in normal hosts.

Histocytochemistry of glycoconjugates in nasal inverted papilloma

In order to investigate the changes in cellular distribution of the glycocalyces in nasal inverted papilloma, formalin-fixed, paraffin-embedded biopsy specimens of inverted papilloma were analyzed by the avidin-biotin-peroxidase complex technique for the demonstration of peanut agglutinin (PNA) receptors, concanavalin A (Canavalia ensiformis agglutinin; ConA) receptors, carcinoembryonic antigen (CEA), and keratin, and compared with normal nasal mucosa, nasal polyps, and papillary adenocarcinoma. The inverted papillomas were positive for PNA and CEA, to the same degree as papillary adenocarcinoma. Their PNA binding was related to the degree of dysplasia. The ConA reaction was intermediate between that of normal mucosa and adenocarcinoma. The results suggest that the alteration of cellular glycoprotein structure in inverted papilloma is associated with its biologic characterization.

Establishing a resuscitation model in rabbits with closed-thoracic cardiopulmonary by-pass

This study aims to establish an animal model of resuscitation in rabbits by using closed-thoracic cardiopulmonary by-pass (CTCPB). The rabbits were randomly divided into four groups according to cardiac arrest times which were 8, 10, 12, and 15 min. Neurologic outcome and blood lactate were determined within 150 min after resuscitation. It was indicated that the rabbits' neurologic functions were progressively injured with prolonged cardiac arrest time. The threshold of circulatory arrest time that induced a vegetative state in the rabbits was between 10 and 12 min. There were no significant differences in cardiac resuscitability among the four groups, as was so for plasma lactate, although it increased significantly from the control levels. The establishment of a small-animal model of resuscitation by using CTCPB, and the problems in dealing with it are also described and discussed in detail in this paper. Our experience indicated that this is a simple, convenient, and economical animal model for the study of resuscitation.

Isolation of a cDNA encoding the largest subunit of TFIIA reveals functions important for activated transcription

Transcription factor IIA has been shown to interact with the TATA-binding protein and to act early during preinitiation complex formation. The human factor is composed of three subunits (alpha, beta, gamma). A human cDNA clone encoding the largest subunit of TFIIA (alpha) was isolated. The recombinant alpha polypeptide, together with the beta and gamma subunits, was capable of reconstituting TFIIA activity. Studies using antibodies raised against recombinant alpha polypeptide demonstrate that TFIIA can be an integral component of the preinitiation complex. We demonstrate that TFIIA not only interacts with TBP but also can associate with the TFIID complex. Functional assays establish that TFIIA has no apparent role in basal transcription but plays an important role in activation of transcription. Interestingly, amino acid sequence analyses of the beta-subunit demonstrate these residues to be entirely contained within the carboxyl terminus of the cDNA clone encoding the alpha-subunit.

Chemistry, binding affinities, and behavioral properties of a new class of "antineophobic" mitochondrial DBI receptor complex (mDRC) ligands

The mitochondrial DBI receptor complex (mDRC; previously called the peripheral benzodiazepine receptors) is linked to the production of neurosteroids such as pregnenolone sulfate, dehydroepiandrosterone sulfate, and others. In order to gain further information as to the function of the mDRC in the brain, we have constructed and tested both in vitro and in vivo a novel series of ligands, 2-arylindole-3-acetamides. The SAR studies detailed herein delineate some of the structural features required for high affinity binding to the mDRCs. In most cases the new ligands were prepared by use of the Fischer indole synthesis. Variations in the length and number of the alkyl groups on the amide nitrogen were probed together with the effects of halogen substituents on one or both of the aryl rings. Some ligands were also synthesized for study which represent conformationally constrained versions of the parent structure. Broad screening studies revealed these indoleacetamides to be highly selective for the mDRC, since they failed to bind with any significant affinity to other receptor systems. Some of the ligands were found to exhibit Ki values in the low nanomolar range for the mDRC as measured by the displacement of [3H]4'-chlorodiazepam. A subset of these ligands was also shown to stimulate pregnenolone formation from the mitochondria of C6-2B glioma cells with an EC50 of about 3 nM. In animal experiments ligands selected for further study were found to exhibit antineophobic effects, in spite of the fact that they exhibit no direct action on GABAA receptors. Consequently, it is postulated that these ligands owe their action to an indirect modulation of GABAA receptor function, presumably by stimulation of neurosteroid production and release from glial cells, followed by neurosteroid modulation of GABA's action on the chloride ion channel conductance of GABAA receptors.

Molecular cloning and characterization of acrA and acrE genes of Escherichia coli

The DNA fragment containing the acrA locus of the Escherichia coli chromosome has been cloned by using a complementation test. The nucleotide sequence indicates the presence of two open reading frames (ORFs). Sequence analysis suggests that the first ORF encodes a 397-residue lipoprotein with a 24-amino-acid signal peptide at its N terminus. One inactive allele of acrA from strain N43 was shown to contain an IS2 element inserted into this ORF. Therefore, this ORF was designated acrA. The second downstream ORF is predicted to encode a transmembrane protein of 1,049 amino acids and is named acrE. Genes acrA and acrE are probably located on the same operon, and both of their products are likely to affect drug susceptibilities observed in wild-type cells. The cellular localizations of these polypeptides have been analyzed by making acrA::TnphoA and acrE::TnphoA fusion proteins. Interestingly, AcrA and AcrE share 65 and 77% amino acid identity with two other E. coli polypeptides, EnvC and EnvD, respectively. Drug susceptibilities in one acrA mutant (N43) and one envCD mutant (PM61) have been determined and compared. Finally, the possible functions of these proteins are discussed.

Stimulation of brain steroidogenesis by 2-aryl-indole-3-acetamide derivatives acting at the mitochondrial diazepam-binding inhibitor receptor complex

The 2-aryl-indole-3-acetamide derivatives, 2-hexyl-indole-3-acetamide (FGIN-1-27) and 2-hexyl-indole-3-acetamide-N-benzene-tricarboxylic acid (FGIN-1-44) displaced [3H]1-(2-chlorophenyl)-N-methyl-N-(1- methylpropyl)-3-isoquinoline-carboxamide([3H]PK 11195) and [3H]4-chlorodiazepam ([3H]4'CD) from binding sites located on the rat brain mitochondrial DBI receptor complex (MDRC) with Ki values in the nanomolar range. Both 2-aryl-indole-3-acetamide derivatives acted as agonists at the MDRC and thereby stimulated the rate of pregnenolone synthesis in isolated rat brain mitochondria; this effect was inhibited by PK 11195, an MDRC ligand that does not possess steroidogenic activity. FGIN-1-27 and FGIN-1-44 failed to bind to other transmitter receptors, including gamma-aminobutyric-A receptors. When administered orally to rats, both FGIN-1-27 and FGIN-1-44 reduced fear of novelty in the elevated plus maze test. This action was prevented by PK 11195, but not by flumazenil. FGIN-1-44, which was rapidly converted to FGIN-1-27 in the rat brain, was 3 to 4 times more potent than FGIN-1-27 in reducing fear of novelty because of its greater bioavailability. FGIN-1-27 increased the brain pregnenolone content in adrenalectomized-castrated rats pretreated with trilostane (in order to prevent metabolism of pregnenolone to progesterone). This increase was blocked by pretreatment with PK 11195. Although FGIN-1-27 and FGIN-1-44 increased the corticosterone concentration in adrenal glands and plasma of hypophysectomized rats in a PK 11195-sensitive manner, both drugs failed to increase adrenal steroidogenesis in sham-operated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcitonin gene-related peptide- and substance P-like-immunoreactive innervation of the anterior pituitary in the rat

In our previous studies substantial amounts of substance P- and calcitonin gene-related peptide-like-immunoreactive nerve fibers have been identified in the anterior pituitary of the monkey and the dog. They were found to be in close proximity to the gland cells, even making synaptic contacts with some types of the gland cells. The present study investigated in detail the calcitonin gene-related peptide- and substance P-like immunoreactivities of the anterior pituitary in the rat. Though the immunoreactive fibers were not as abundant as in the anterior pituitary of the monkey and the dog, they still appeared in notable amounts. The calcitonin gene-related peptide- and substance P-like-immunoreactive nerve fibers occurred mostly as thin, tortuous, and densely varicose fibers, weaving among the gland cells. They are widely distributed, more in the central part of the gland. Double-immunostaining proved nearly complete co-localization of these two peptides in the nerve fibers. It is hypothesized that the anterior pituitary can be regulated by direct neural factors as well as humoral factors.

Participation of mitochondrial diazepam binding inhibitor receptors in the anticonflict, antineophobic and anticonvulsant action of 2-aryl-3-indoleacetamide and imidazopyridine derivatives

The 2-hexyl-indoleacetamide derivative, FGIN-1-27 [N,N-di-n-hexyl-2- (4-fluorophenyl)indole-3-acetamide], and the imidazopyridine derivative, alpidem, both bind with high affinity to glial mitochondrial diazepam binding inhibitor receptors (MDR) and increase mitochondrial steroidogenesis. Although FGIN-1-27 is selective for the MDR, alpidem also binds to the allosteric modulatory site of the gamma-aminobutyric acidA receptor where the benzodiazepines bind. FGIN-1-27 and alpidem, like the neurosteroid 3 alpha,21-dehydroxy-5 alpha-pregnane-20-one (THDOC), clonazepam and zolpidem (the direct allosteric modulators of gamma-aminobutyric acidA receptors) delay the onset of isoniazid and metrazol-induced convulsions. The anti-isoniazid convulsant action of FGIN-1-27 and alpidem, but not that of THDOC, is blocked by PK 11195. In contrast, flumazenil blocked completely the anticonvulsant action of clonazepam and zolpidem and partially blocked that of alpidem, but it did not affect the anticonvulsant action of THDOC and FGIN-1-27. Alpidem, like clonazepam, zolpidem and diazepam, but not THDOC or FGIN-1-27, delay the onset of bicuculline-induced convulsions. In two animal models of anxiety, the neophobic behavior in the elevated plus maze test and the conflict-punishment behavior in the Vogel conflict test, THDOC and FGIN-1-27 elicited anxiolytic-like effects in a manner that is flumazenil insensitive, whereas alpidem elicited a similar anxiolytic effect, but is partially blocked by flumazenil. Whereas PK 11195 blocked the effect of FGIN-1-27 and partially blocked alpidem, it did not affect THDOC in both animal models of anxiety.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of carotenoid and bacteriochlorophyll biosynthesis genes and identification of an evolutionarily conserved gene required for bacteriochlorophyll accumulation

The temporal expression of ten clustered genes required for carotenoid (crt) and bacteriochlorophyll (bch) biosynthesis was examined during the transition from aerobic respiration to anaerobiosis requisite for the development of the photosynthetic membrane in the bacterium Rhodobacter capsulatus. Accumulation of crtA, crtC, crtD, crtE, crtF, crtK, bchC and bchD mRNAs increased transiently and coordinately, up to 12-fold following removal of oxygen from the growth medium, paralleling increases in mRNAs encoding pigment-binding polypeptides of the photosynthetic apparatus. The crtB and crtI genes, in contrast, were expressed similarly in the presence or absence of oxygen. The regulation patterns of promoters for the crtA and crtI genes and the bchCXYZ operon were characterized using lacZ transcriptional fusion and qualitatively reflected the corresponding mRNA accumulation patterns. We also report that the bchI gene product, encoded by a DNA sequence previously considered to be a portion of crtA, shares 49% sequence identity with the nuclear-encoded Arabidopsis thaliana Cs chloroplast protein required for normal pigmentation in plants.

Analysis of the promoter and regulatory sequences of an oxygen-regulated bch operon in Rhodobacter capsulatus by site-directed mutagenesis

The biosynthesis of pigments (carotenoids and bacteriochlorophylls) in the photosynthetic bacterium Rhodobacter capsulatus is regulated by the oxygen concentration in the environment. However, the mechanism of this regulation has remained obscure. In this study, transcriptional fusions of the bchCXYZ promoter region to lacZ were used to identify the promoter and regulatory sequences governing transcription of these bacteriochlorophyll biosynthesis genes. The promoter region was identified in vivo by making deletions and site-directed mutations. The 50 bp upstream of the promoter region was shown to be required for the oxygen-dependent transcriptional regulation of bchCXYZ. A previously described palindrome sequence is also likely involved in the regulation. A gel mobility shift assay further defined the interaction of transcription regulators with these DNA sequence elements in vitro and demonstrated that a DNA-protein complex is formed at this promoter region. Since the suggested promoter sequence and the palindrome sequence are found upstream of several other bch and crt operons, these sequences may be responsible for regulating oxygen-dependent pigment biosynthesis at the level of transcription in R. capsulatus. In addition, these cis-acting DNA elements are not found upstream of puh and puf operons, which encode the structural polypeptides of the reaction center and light-harvesting I complexes. This observation supports the model of different regulatory mechanism for the pigment biosynthesis enzymes and structural polypeptides required for the production of the photosynthetic apparatus.

[The study on prethrombotic state in patients with chronic obstructive pulmonary disease and cor pulmonale]

We measured PT, TT, KPTT, Fg, vWF, AT-IIIAg, AT-IIIA, alpha 2M, TXB2, 6-keto-PGF1 alpha, PLg, tPAAg, tPAA and PAI of patients with acute onset of chronic bronchitis, pulmonary emphysema, and cor pulmonale. The results were that many above parameter had a worsening tendency along with deterioration of COPD, and Fg, vWF, TXB2, 6-keto-PGF1 alpha, tPAA and PAI were more sensitive than others. The analysis of multiple liner regression of 22 blood items in patients with cor pulmonale showed that pH, PaO2, PaCO2 had correlation with many items of prethrombotic state. We consider that in the progress of COPD, prethrombotic state gradually appeared and aggravated. The causes may be related with repeatedly infections, low O2, high CO2 and imbalance of acid-base equilibrium.

Dynamics of DNA supercoiling by transcription in Escherichia coli

The relative rotation between RNA polymerase and DNA during transcription elongation can lead to supercoiling of the DNA template. However, the variables that influence the efficiency of supercoiling by RNA polymerase in vivo are poorly understood, despite the importance of supercoiling for DNA metabolism. We describe a model system to measure the rate of supercoiling by transcription and to estimate the rates of topoisomerase turnover in Escherichia coli. Transcription in a strain lacking topoisomerase I can lead to optimal supercoiling, wherein nearly one positive and one negative superturn are produced for each 10.4 base pairs transcribed. This rapid efficient supercoiling is observed during transcription of membrane-associated gene products, encoded by tet (the gene for tetracycline resistance) and phoA (the gene for E. coli alkaline phosphatase), when the genes are oppositely oriented. Replacement of tet by cat, the gene from Tn9 encoding resistance to chloramphenicol, whose gene product is soluble in the cytosol, reduces the efficiency of supercoiling by RNA polymerase. In a wild-type topoisomerase background, both gyrase and topoisomerase I are kinetically competent to relieve superturns produced by transcription. These results suggest that the level of DNA supercoiling in vivo is probably determined by topoisomerase activity, not by transcription.

High dose chemotherapy and autologous bone marrow transplantation in advanced Hodgkin's disease

OBJECTIVE

To present the use of high dose chemotherapy with autologous bone marrow transplantation as salvage therapy for advanced Hodgkin's disease in Australia.

DESIGN

A prospective open study for patients whose disease was resistant to conventional treatment.

SETTING

The bone marrow transplantation units of four Australian tertiary hospitals.

PATIENTS

Seventeen patients (median age 30 years) entered and completed the study. The stage of the disease at initial diagnosis was I or II (seven patients), III (seven patients) and IV (three patients). Histological types were lymphocyte predominant (one), nodular sclerosis (12), mixed cellularity (three) and unknown (one). Therapy before consideration for transplantation included radiotherapy (13), mustine, vincristine, procarbazine and prednisone (MOPP--17 patients) or doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD--13 patients) and other chemotherapy regimens (five). The median interval from diagnosis to transplantation was 29 months (range, 9-178 months). The patient's disease was classified as sensitive (nine) or resistant (eight) to treatment, depending on the response to the most recent course of chemotherapy.

INTERVENTIONS

Morphologically normal autologous bone marrow was harvested and cryopreserved. The conditioning regimen given was cyclophosphamide, carmustine and etoposide (14) or busulphan and cyclophosphamide (three). The marrow was then infused.

MAIN OUTCOME MEASURES

Remission (complete or partial), disease-free survival and overall survival.

RESULTS

Over all, 10 of 17 patients (59%) entered or remained in complete remission and four of 17 (24%) achieved partial remission. The overall actuarial survival at 30 months was 70%. Eight of the nine patients with treatment-sensitive disease (89%) remain disease-free at a median of 22 months (range, 18-29 months) after transplantation. Two of the eight patients with resistant disease (25%) are disease-free at 20 and 28 months. There was one procedure-related death from haemorrhage and four disease-related deaths at six, seven, eight and 13 months after transplantation.

CONCLUSION

Autologous bone marrow transplantation may provide an effective salvage therapy in advanced Hodgkin's disease, particularly for patients with treatment-sensitive disease and a low tumour burden.

2-Aryl-3-indoleacetamides (FGIN-1): a new class of potent and specific ligands for the mitochondrial DBI receptor (MDR)

The 2 aryl-3-indoleacetamides (FGIN-1) are a new class of compounds that potently (nM) and selectively bind to glial mitochondrial diazepam binding inhibitor (DBI) receptors (MDR), previously called peripheral benzodiazepine receptors, and increase mitochondrial steroidogenesis. The high-affinity binding of FGIN-1 to MDR derivatives depends on the following chemical characteristics: 1) the dialkylation of the amide; 2) the chain length of this alkyl substitution; and 3) the halogenation of aryl groups appended to the indole nucleus. FGIN-1 derivatives do not bind to gamma-aminobutyric acid (GABAA), GABAB, glycine, glutamate, dopamine, serotonin, opiate, cholecystokinin, beta adrenergic, cannabinoid or sigma receptors. FGIN-1-27 [N, N-di-n-hexyl 2-(4-fluorophenyl)indole-3-acetamide] enters the brain, and for this reason, this FGIN-1 compound is potent and efficacious behaviorally. Like the neurosteroid 3 alpha-5 alpha tetrahydrodeoxycorticosterone (THDOC), FGIN-1-27 delays the onset of isoniazid-induced convulsions, but fails to delay the onset of bicuculline-induced convulsions. However, differently from THDOC, the FGIN-1-27 anticonvulsant action is blocked by the isoquinoline carboxamide PK 11195. In the elevated plus maze test, FGIN-1-27 inhibits neophobia manner that is antagonized by PK 11195 but not by flumazenil. Because FGIN-1-27 binds to MDR and does not bind to the GABAA receptors, it is inferred that FGIN-1-27 may act on GABAA receptors indirectly, presumably via a stimulation of neurosteroid synthesis and release from glial cells.

Third ventricular subependymal oxytocin-like immunoreactive neuronal plexus in the rat

In a previous retrograde tracing study, a dense subependymal neuronal plexus was found along the anterior ventral third ventricle that projects to the posterior pituitary. In the work reported here, the oxytocin-like immunoreactive neurons of this plexus were studied in detail. It has a population of about 650 cells with a great wealth of dendrites. The neurons are of magnocellular neurosecretory type with long straight dendrites running parallel to the ependyma. The plexus is composed of a dorsal and a ventral part. The dorsal part consists of about 75% of the whole population and is most dense at the levels of the anterior and medial magnocellular paraventricular nuclei. Their dendrites appear vacuous in immunohistochemically stained sections and have a tendency to form fascicles. The ventral part is more sparse. The dendrites of the subependymal plexus are well organized so the anteriorly located ones tend to be directed rostrally and the posteriorly ones caudally. The functional significance of the plexus is discussed.

Immune effect of tumor-infiltrating lymphocytes and its relation to the survival rate of patients with ovarian malignancies

Tumor-infiltrating lymphocytes (TIL) in histological sections from 94 patients with ovarian malignancies were quantitated for their relation to the prognosis of the patients. It was found that the degree of lymphocyte infiltration directly affected the patients' survival rate and also related to clinical staging of the patients, as well as grading and histologic typing of the tumor. T lymphocytes characterized by alpha-naphthyl acetate (ANAE) staining were the major cells in the stroma of ovarian malignancies. Ultrastructural study of TIL and cancer cells suggested that tumor cell degeneration is related to the effect of TIL.

[Experiment on stability of total flavones in guanshu tablet]

This paper reports the study on the stability of total flavones in guanshu tablet by heating and accelerating method. Taking the total flavone contents of the tablet as the index, the time of validity of guanshu tablet at room temperature 25 degrees C is calculated to be 9.6 years by chemical kinetic analysis.

A preliminary study on natural killer activity in patients with gynecologic malignancies

A release assay of 125IUdR-labelled K562 cells as target cells was performed for measuring natural killer (NK) activity of mononuclear cells in the peripheral blood of 92 cases, including 42 healthy women, 22 patients with gynecological benign tumors, and 28 patients with gynecological malignancies. The NK activity of malignant tumor group was obviously lower than that of healthy women and of benign tumor group, suggesting that a defective NK activity was present in the patients with gynecological malignancies. The NK activity in patients with ovarian malignant tumors was much lower than in those with cervical cancer, the difference being of statistical significance. In this study the leukocyte interferon was investigated for its effects on the NK activity of peripheral blood mononuclear cells from 4 cases of gynecological malignancies. The level of NK activity ascended significantly in every case nearly to normal. The augmentation of NK activity by interferon may be used as a new immunotherapy for gynecological malignancies.

Etoposide in acute nonlymphocytic leukemia. Australian Leukemia Study Group

Previously untreated patients with acute nonlymphocytic leukemia (ANLL) aged 15 to 70 years were randomized to either cytosine arabinoside 100 mg/m2/d continuous intravenous (IV) infusion days 1 through 7, daunorubicin 50 mg/m2/d IV days 1 through 3 (7-3), or the same drugs intensified with etoposide 75 mg/m2/d IV days 1 through 7 (7-3-7) as induction therapy. Patients achieving complete remission (CR) received two courses of consolidation therapy (5-2 or 5-2-5) followed by maintenance therapy. Of 264 eligible patients, CR occurred in 56% of 7-3 and 59% of 7-3-7 patients; 7-3-7 significantly improved remission duration (P = .01). The median remission duration was 12 months for 7-3 and 18 months for 7-3-7. Survival was similar when the two arms were compared overall. Subset analysis performed to identify patients with the most benefit showed that etoposide significantly prolonged remission duration in younger patients (less than 55 years) with a median of 12 months for 7-3 and 27 months for 7-3-7 (P = .01). Survival appeared to be prolonged with 7-3-7 in patients aged less than 55 years, with a median of 9 months for 7-3 as compared with 17 months for 7-3-7 (P = .03). In older patients (aged greater than or equal to 55 years), 7-3-7 was more toxic, with significantly more severe [World Health Organization (WHO) grade 3 or 4] stomatitis (P = .02) and no additional clinical benefit. Hematologic toxicity for induction courses was similar, with granulocytopenia less than 0.5 x 10(9)/L for a median of 16 days per course for 7-3 and 15 days for 7-3-7. Hematologic toxicity was more severe for 5-2-5 consolidation courses (P = .003). Induction and consolidation therapy intensified with etoposide resulted in significantly improved remission duration but not survival.

The effect of dnaA protein and n' sites on the replication of plasmid ColE1

The role of the dna A protein in the replication of plasmid ColE1 and its derivatives was examined. Wild-type and mutant ColE1 plasmids were compared as to their ability to replicate in an in vitro replication system supplemented with ammonium sulfate fractionated extracts from a dnaA-overproducing strain. Synthesis on plasmid templates containing the wild-type origin of replication was stimulated 1.3-fold by addition of the dnaA-overproducing extract. A larger effect was observed after deletion of the primosome assembly site, the n' site, on the leading strand. On the latter template, synthesis was only about one-half that observed with the wild-type templates, but synthesis could be restored to normal levels by addition of the dnaA-overproducing fractions. When the n' site on the lagging strand of pBR322 was deleted, synthesis in the in vitro replication system was reduced to less than 10% of levels seen with intact templates. dnaA-overproducing extract did not restore activity since the dnaA site was also deleted on these plasmids. To verify that the observed stimulation of wild-type and leading strand n' site mutants was due to the dnaA protein, dnaA protein was purified to greater than 50% homogeneity, and antiserum was prepared. The purified protein stimulated synthesis on the plasmid templates to the same extent as the overproducing extracts, and dnaA antiserum blocked stimulation both by extracts and by the purified protein. Thus, dnaA protein, and, by inference, the dnaA recognition site at the ColE1 origin of replication seem to be important for ColE1 replication. The effect of dnaA protein is enhanced when the n'site is defective, suggesting that the dnaA protein plays a role similar to that of the proteins i, n, n', and n'' in directing primosome assembly, as proposed by Seufert, W., and Messer, W. ((1987) Cell 48, 73-78).

A noninvasive technique to assess completeness of spinal cord lesions in humans

The effect of scalp stimulation delivered through electrodes overlying the motor cortex was evaluated in five healthy subjects and six patients with traumatic spinal cord injury. The latency to the onset of the electromyographic response was measured in the biceps brachii and abductor pollicis brevis muscles. In all the patients, latencies to the muscle (biceps brachii) whose innervation originated above the lesion were in the normal range; whereas, latencies to the muscle (abductor pollicis brevis) whose innervation originated below the lesion were prolonged. Electromyographic signals were recorded in muscles which showed no voluntary motor activity. No lateral differences in latencies were found in healthy subjects; however, in the patients, significant differences were obtained between the right and left abductor pollicis brevis muscles. The results of this study demonstrate that the spinal cord of patients with a lesion deemed to be clinically complete, contains nerve fibers which descend through the lesion and are capable of conveying impulses leading to muscle contraction.

Expression of polypeptide segments of the human complement component C3 in E. coli: genetic and immunological characterization of cDNA clones specific for the alpha-chain of C3

The third component of complement C3 and its fragments have a central role in a variety of host defense mechanisms. The identification of functionally relevant C3 domains is important because of the marked functional versatility of the C3 molecule. Several human C3 cDNA clones from a human liver cDNA library were isolated and characterized. A bacterial expression vector system was used to express cDNA clones that were identified by an immunological screening procedure. The C3 cDNA clones produced in E. coli the hybrid proteins consisting of cro-beta-galactosidase and polypeptide segments of human C3, as revealed by Western blotting with antisera to human C3. The C3 moiety of the hybrid proteins had a m.w. of up to 46.000. Polyclonal antibodies against the C3 segments expressed by one of the C3 cDNA clones (ReC3-1) have been raised in mice and rabbit, and in addition, a monoclonal antibody was produced. The antisera and the monoclonal antibody reacted in Western blotting analysis selectively with the alpha-chain, but not the beta-chain of human C3. Restriction mapping of the different cDNA clones was performed, and revealed that the different clones were partially overlapping. The ReC3-1 cDNA clone included a 0.7 kb noncoding region at the 3' terminal end of the C3 cDNA. One of the restriction sites (Hind III) identified in the ReC3-1 cDNA clone was not present in the recently published sequence of human C3 cDNA. This difference in nucleotide sequence provides direct evidence for C3 polymorphism at the DNA level. The combination of immunologic procedures with recombinant DNA methodology should facilitate additional analysis of the structure-function relationship of the C3 molecule.

Expression of polypeptide segments of the human complement component C3 in E. coli: genetic and immunological characterization of cDNA clones specific for the alpha-chain of C3

The third component of complement C3 and its fragments have a central role in a variety of host defense mechanisms. The identification of functionally relevant C3 domains is important because of the marked functional versatility of the C3 molecule. Several human C3 cDNA clones from a human liver cDNA library were isolated and characterized. A bacterial expression vector system was used to express cDNA clones that were identified by an immunological screening procedure. The C3 cDNA clones produced in E. coli the hybrid proteins consisting of cro-beta-galactosidase and polypeptide segments of human C3, as revealed by Western blotting with antisera to human C3. The C3 moiety of the hybrid proteins had a m.w. of up to 46.000. Polyclonal antibodies against the C3 segments expressed by one of the C3 cDNA clones (ReC3-1) have been raised in mice and rabbit, and in addition, a monoclonal antibody was produced. The antisera and the monoclonal antibody reacted in Western blotting analysis selectively with the alpha-chain, but not the beta-chain of human C3. Restriction mapping of the different cDNA clones was performed, and revealed that the different clones were partially overlapping. The ReC3-1 cDNA clone included a 0.7 kb noncoding region at the 3' terminal end of the C3 cDNA. One of the restriction sites (Hind III) identified in the ReC3-1 cDNA clone was not present in the recently published sequence of human C3 cDNA. This difference in nucleotide sequence provides direct evidence for C3 polymorphism at the DNA level. The combination of immunologic procedures with recombinant DNA methodology should facilitate additional analysis of the structure-function relationship of the C3 molecule.

Human B cell development. I. Phenotypic differences of B lymphocytes in the bone marrow and peripheral lymphoid tissue

The phenotype of B lineage cells (TdT+, pre-B, IgM+, IgD-, and IgM+,IgD+) in infant and adult human bone marrow was compared with that of B cells seen in peripheral tissues such as tonsil and blood. The range of B cell-associated antibodies used included four reagents with greater than 90% reactivity on peripheral B cells: RFB4 and To15 (both p135, corresponding to CD22), RFB6 (p140 corresponding to CD21), and Y29/55, a unique B cell-specific antibody. In addition, AL-1, an antibody with virtually no reactivity against peripheral B cells was also used. The BM cell subpopulations were heterogeneous in respect of antibody reactivity. The TdT+, pre-B and IgM+, IgD- cells were AL-1+ but did not express membrane antigens recognized by the antibodies To15, RFB4 (CD22), and RFB6 (CD21). TdT+, pre-B cells, and 50% of IgM+, IgD- BM B cells were also unreactive with antibody Y29/55, the other 50% being Y29/55+. In contrast, the IgM+,IgD+ BM B cells, like peripheral B cells, were positive with antibodies To15, RFB4, RFB6, and Y29/55, but reacted only in small numbers with AL-1. The orderly differentiation-linked display of these antigens was also suggested by the findings that normal TdT+, pre-B, and IgM+,IgD- cells expressed the To15 and RFB4 (CD22) antigens in their cytoplasm (in the Golgi region). This observation was confirmed in malignant common acute lymphoblastic and pre-B blast cells, as well as in the corresponding permanent cell lines KM3 and NALM-6. In these lines the membrane expression of To15 and RFB4 could be induced by phorbol ester during a 48 to 72 hr culture period.

Human B cell development. I. Phenotypic differences of B lymphocytes in the bone marrow and peripheral lymphoid tissue

The phenotype of B lineage cells (TdT+, pre-B, IgM+, IgD-, and IgM+,IgD+) in infant and adult human bone marrow was compared with that of B cells seen in peripheral tissues such as tonsil and blood. The range of B cell-associated antibodies used included four reagents with greater than 90% reactivity on peripheral B cells: RFB4 and To15 (both p135, corresponding to CD22), RFB6 (p140 corresponding to CD21), and Y29/55, a unique B cell-specific antibody. In addition, AL-1, an antibody with virtually no reactivity against peripheral B cells was also used. The BM cell subpopulations were heterogeneous in respect of antibody reactivity. The TdT+, pre-B and IgM+, IgD- cells were AL-1+ but did not express membrane antigens recognized by the antibodies To15, RFB4 (CD22), and RFB6 (CD21). TdT+, pre-B cells, and 50% of IgM+, IgD- BM B cells were also unreactive with antibody Y29/55, the other 50% being Y29/55+. In contrast, the IgM+,IgD+ BM B cells, like peripheral B cells, were positive with antibodies To15, RFB4, RFB6, and Y29/55, but reacted only in small numbers with AL-1. The orderly differentiation-linked display of these antigens was also suggested by the findings that normal TdT+, pre-B, and IgM+,IgD- cells expressed the To15 and RFB4 (CD22) antigens in their cytoplasm (in the Golgi region). This observation was confirmed in malignant common acute lymphoblastic and pre-B blast cells, as well as in the corresponding permanent cell lines KM3 and NALM-6. In these lines the membrane expression of To15 and RFB4 could be induced by phorbol ester during a 48 to 72 hr culture period.

cis-acting mutations that affect rop protein control of plasmid copy number

A number of pMB1 derivatives provide a trans-acting function that can suppress lethal runaway replication of a temperature-sensitive copy-number mutant of NTP1. Deletion analysis indicates that the region of the pMB1 genome that contains the rop gene is required for this suppression. Mutant derivatives of the temperature-sensitive copy-number mutant plasmid whose conditional lethal phenotype is not suppressed in trans by the region encoding the rop gene have been isolated. These rop-insensitive derivatives contain single nucleotide changes within the RNA I coding region.

Iodine trapping and organification in patients with chronic renal failure

In vitro thyroid function tests were studied in 30 patients on regular hemodialysis. In addition, 8 patients (one not yet dialyzed) underwent perchlorate discharge testing and the salivary to plasma ratio of 131I was measured to identify defects in iodine uptake or organification. When compared with 35 healthy controls, uremic patients had lower total T4 (5.8 +/- 0.4 vs 8.6 +/- 0.3 micrograms/100 ml) and total T3 (81 +/- 6 vs 124 +/- 5 ng/100 ml) but T3RU was higher in dialysis patients (35.5 +/- 0.9 vs 28 +/- 0.5%, P less than 0.01). The TSH levels were not different from those of controls. The RAI uptake 1 h after perchlorate was significantly higher than the control valve (0.6 +/- 0.14 vs 0.06 +/- 0.04, P less than 0.05). Similarly, the salivary to plasma ratio of 131I was higher in patients with chronic renal failure (70 +/- 10:1 vs 40 +/- 4:1). It is concluded that there is altered iodine trapping in CRF patients but iodine organification appears to be normal.

In vitro dissolution of dapsone

Los normal samples of dapsone (DDS) were prepared in which the geometric mean diameter ranged from 20 to 50 micron while the geometric standard deviation was in the range 1.62 to 1.88. Using a simple in vitro flow-through dissolution cell at 37 degrees C, the data obtained were found to fit the Hixson-Crowell cube root dissolution law up to a critical time, Tc, where a distinct break occurred. Such a biphasic phenomenon has been predicted by other workers and is related to the time at which the smallest particles present have undergone dissolution. The initial slopes of the cube root dissolution plots were shown to be directly related to the reciprocal of the geometric mean diameter.