TUF factor binds to the upstream region of the pyruvate decarboxylase structural gene (PDC1) of Saccharomyces cerevisiae

The upstream activation site of the pyruvate decarboxylase gene, PDC1, of Saccharomyces cerevisiae contains an RPG box, and mediates the increase in expression of a PDC1-lacZ fusion gene during growth on glucose. Oligonucleotide replacement experiments indicate that the RPG box functions as an absolute activator of expression, but other elements (possibly CTTCC repeats) are required for carbon source regulation, and maximal expression. Gel retardation and oligonucleotide competition experiments suggest that the DNA binding factor TUF interacts with the RPG box in the upstream region of PDC1. Binding of TUF factor is not carbon source dependent in in vitro experiments, and is probably not responsible for glucose induction of PDC1 expression.

Recovery of an epitope recognized by a novel monoclonal antibody from airway lavage during experimental induction of chronic bronchitis

Prolonged exposure of dogs to high concentrations of SO2 gas results in a syndrome with many of the characteristics of human chronic bronchitis, including cough and chronic mucous hypersecretion as well as airway obstruction. We developed and used a novel monoclonal antibody, GB-4B, raised against epithelial glycoprotein isolated from human hypersecretory mucus to probe airway lavage samples from dogs before and during prolonged exposure to SO2 gas. There were relatively low mean titers of the epitope recognized by GB-4B in airway lavage fluid as evidenced by enzyme-linked immunosorbent assay before exposure to SO2 gas. After 25 to 50 wk of SO2 exposure, the dogs showed a significant increase in pulmonary resistance and there was a significant increase in the titer of the epitope in the airway lavage fluid. Using the same antibody immunohistochemical analysis of airway tissues from SO2-exposed dogs revealed patchy staining of the mucous glands and airway secretory cells and dense staining along the airway surface; airway tissue from control dogs and one SO2-exposed dog whose lavage fluid did not contain the epitope showed little or no staining. These data demonstrate that similar mucin epitopes appear in airway lavage fluid under hypersecretory conditions in both animals and humans. The epitope may have utility as a marker of chronic mucous hypersecretion.

The cytochrome b of the sea urchin Paracentrotus lividus is naturally resistant to myxothiazol and mucidin

The ubiquinol:cytochrome c reductase activity of Paracentrotus lividus mitochondria is relatively insensitive to the specific inhibitors myxothiazol and mucidin. The I50 of myxothiazol and mucidin are three and two orders of magnitude higher, respectively, in P. lividus than in bovine heart mitochondria. The natural resistance of the P. lividus reductase to these inhibitors can be correlated with a single amino replacement, an alanine for a glycine at position 143, in the sequence of cytochrome b. This position is located in a conserved region of the molecule, believed to be important in the oxidation of ubiquinol by the reductase.

Plasma and tissue vitamin E concentrations in sheep after administration of a single intraperitoneal dose of dl-alpha-tocopherol

Blood plasma and tissue Vitamin E concentrations were determined in 20 sheep following a single i.p. dose of 5 g of dl-alpha-tocopherol. In addition, five sheep were used as controls (no treatment and killed at d 0). From the 20 vitamin E-dosed sheep, 4 were slaughtered on d 3, 6, 10, 15 and 28 after dosing. There was a significant time effect in alpha-tocopherol concentrations in all tissues. In most tissues, the peak alpha-tocopherol concentration was at 3 d postdosing. Uptake varied among the different tissues examined. Three days postdosing, a large uptake of vitamin E by the liver was observed; this supports the concept that hepatic tissues are a target organ for vitamin E action. Also at 3 d uptake was pronounced in spleen and lung. Vitamin E concentrations in the other body tissues at d 3 postdosing increased considerably, but to a lesser degree than those in liver, spleen and lung. Vitamin E concentration in all tissues declined 3 d after i.p. dosing.

Identification of an upstream activation site in the pyruvate decarboxylase structural gene (PDC1) of Saccharomyces cerevisiae

The upstream region of the Saccharomyces cerevisiae pyruvate decarboxylase structural gene, PDC1, has been isolated and fused to the indicator gene Escherichia coli lacZ. 1.2 kb of the upstream region has been sequenced. The PDC1-lacZ fusion has been integrated at the ura3-52 locus in the yeast genome, and has a basal level of expression on ethanol. On glucose media this level is increased 30-50 fold. An upstream activation site, UASpdc, between 793 and 535 bp upstream from the ATG of PDC1, which mediates the response to glucose has been identified by deletion analysis. The UASpdc contains a consensus RPG box, originally identified in ribosomal protein genes (Leer et al. 1985). The function of UASpdc is independent of distance from the ATG. There is also an upstream repressing sequence located between 535 and 385 bp upstream from the translational start of PDC1.

Klinefelter's syndrome: an analysis of the origin of the additional sex chromosome using molecular probes

The results of our study of the origin of the additional X chromosome in 39 males with a 47,XXY chromosome constitution are reported. We used a total of 20 X-linked RFLPs and successfully determined the origin of all 32 patients in whom DNA from both parents was available, and a further 3 in whom DNA was available from the patient and mother only. Males whose additional X chromosome was maternal in origin were further investigated using an X-linked centromere specific probe to determine the cell division at which the error occurred. Our results showed 53% of the non-disjunction to be attributable to pat mei I errors, 34% to mat mei I errors, 9% to mat mei II errors and 3% to a post-zygotic mitotic error. In the great majority of patients resulting from an error of maternal meiosis there was clear evidence of recombination involving the non-disjoined chromosomes, suggesting that absence of recombination is not an important aetiological factor in non-disjunction of the X chromosome in female meiosis. There was no alteration of parental age associated with the paternally derived 47,XXY males but a marked increase in maternal age among the maternally derived 47,XXY males, the increase being associated with mat mei I but not mat mei II errors. The proportion of paternally and maternally derived cases was similar among different ascertainment classes, suggesting that there is no dramatic effect of parental origin of the additional X chromosome on the phenotype of 47,XXY males.

GAL1-GAL10 divergent promoter region of Saccharomyces cerevisiae contains negative control elements in addition to functionally separate and possibly overlapping upstream activating sequences

The upstream activating sequence (UASG) of the adjacent and divergently transcribed GAL1 and GAL10 promoters of Saccharomyces cerevisiae regulates the induction of the corresponding genes in response to the presence of galactose. We constructed chimeric yeast promoters in which a different UAS, UASC from the iso-1-cytochrome c (CYC1) gene of S. cerevisiae, was fused at different locations upstream of GAL1 (UASC-GAL1 promoters) or GAL10 (UASC-GAL10 promoters) and used to monitor the activity of UASG in cells grown in the presence or absence of galactose. Though the CYC1 promoter is fully induced in yeast grown in glycerol medium, UASC-GAL chimeric promoters containing UASG were repressed as much as 400-fold (UASC-GAL1) or 1350-fold (UASC-GAL10) in this growth medium. Several distinct portions of the GAL1-GAL10 divergent promoter region blocked the UASC-induced expression of the GAL1 and GAL10 promoters, whereas others did not, suggesting that several distinct negative control elements are present that may repress transcription of GAL1 and GAL10 in the absence of galactose. The approximate locations of these negative control elements were delimited to sites adjacent to or possibly overlapping the sites at which the positive control protein GAL4 binds in UASG. Deletion derivatives of GAL4 that fail to induce transcription from the wild-type GAL promoters but retain the DNA binding domain significantly derepressed the expression of the UASC-GAL chimeric promoters. These results, combined with those of earlier studies, suggest the possibility that GAL4 normally induces transcription of GAL1 and GAL10 by blocking the activity of these negative control elements, in addition to stimulating transcription by a mechanism of positive control.

Identification, purification, and characterization of a mast cell-associated cytolytic factor related to tumor necrosis factor

The role of mast cells and mast-cell-derived factors in natural cytotoxic reactions was investigated. Cultured and freshly isolated murine mast cells are shown to be cytotoxic to WEHI-164 and YAC-1 targets in 18-hr viability assays but not in 4-hr assays. Here, we describe a cytotoxic factor in murine mast cells that is immunologically related to tumor necrosis factor (TNF). This TNF-like factor lyses WEHI-164 cells with a slow time course requiring 16-20 hr for the lytic reaction to complete. Antibodies specific for human and murine TNF and human lymphotoxin partially block mast cell lysis of WEHI-164 cells. These antibodies react on immunoblots with one major mast cell protein band of 50 kDa. Immunoblot analysis shows this factor in cloned and uncloned cultured mouse mast cells and in mature "connective tissue-type" mast cells freshly purified from rat or mouse peritoneal cavities. The amount of this factor is greatly enhanced in cells that have been stimulated with a combination of phorbol ester/concanavalin A or bacterial lipopolysaccharide. Subcellular fractionation analysis of mast cells with Percoll gradients reveals two pools of TNF-related cytotoxic activity that are associated with free cytosolic material and granule fractions. In contrast to cytotoxic T lymphocytes and natural killer cells, granule-enriched fractions of mast cells do not contain any hemolytic activity. The localization of the TNF-like molecule in mast cell granules may play a strategical role in the rapid delivery of this mediator to the target cell membrane following cell surface stimulation and degranulation.

Anxiety management for persistent generalised anxiety

A preliminary controlled investigation of the effectiveness of Anxiety Management as a treatment for generalised anxiety disorder (GAD) is described. Patients with a primary diagnosis of GAD, in which the current episode had lasted for at least 6 months but not more than 2 years, were included. Anxiety Management, a self-help treatment including procedures for managing somatic and cognitive symptoms, and for dealing with avoidance and low self-confidence, was given either immediately or after a 12-week waiting period. The average length of treatment was 8.7 sessions. Highly significant changes in anxiety, depression, and problem ratings were shown after treatment. These changes were replicated when the waiting list group had also received treatment, and gains were maintained by both groups for 6 months. Similar degrees of improvement and maintenance of change were shown in subgroups with and without minor depressive disorder or recurrent panic attacks.

A novel approach for obtaining and identifying monoclonal antibodies that react with differentiation-specific antigens using human hybrid cells

HeLa X keratinocyte hybrid cells have been used as immunogens to generate monoclonal antibodies against differentiation-specific antigens. A key feature of the experimental system is that the hybrid cells are undifferentiated in culture and yet terminally differentiate in the mouse. The properties of these cells allow one a facile approach to obtaining and characterizing monoclonal antibodies against differentiation-specific antigens. Use of hybrid cells derived from HeLa X differentiated cell fusions as immunogens should prove to be a general method for identifying differentiation-specific antigens from a variety of differentiated cell types.

Ischemic oculopathy

A 58-year-old woman had unilateral visual loss, anterior uveitis, rubeosis, and glaucoma. She subsequently was found to have a complete occlusion of the internal carotid on the same side. The clinician is reminded to consider a diagnosis of carotid insufficiency in elderly patients with anterior uveitis or rubeosis of obscure origin.

An outbreak of Pseudomonas mastitis in dairy cows

An outbreak of mastitis in a dairy herd is described in which the causative organism was Pseudomonas aeruginosa. Cases occurred either in dry cows or in animals which had very recently calved. The fact that all four quarters were involved is a very strong indication that the bacteria had been introduced in the dry cow therapy.

The mechanical properties of bone tissue in children

Specimens of femoral cortical bone from eighteen subjects between two and forty-eight years old were loaded in bending. Compared with the bone of adults, that of children had a lower modulus of elasticity, a lower bending strength, and a lower ash content. However, the children's bone deflected more and absorbed more energy before breaking. It also tended to absorb more energy after fracture had started. The typical greenstick fracture surface of many specimens of children's bone requires more energy for its production than the relatively smooth surface of adult specimens.