Failure to induce a DNA repair gene, RAD54, in Saccharomyces cerevisiae does not affect DNA repair or recombination phenotypes.

The Saccharomyces cerevisiae RAD54 gene is transcriptionally regulated by a broad spectrum of DNA-damaging agents. Induction of RAD54 by DNA-damaging agents is under positive control. Sequences responsible for DNA damage induction (the DRS element) lie within a 29-base-pair region from -99 to -70 from the most proximal transcription start site.

Two DNA repair and recombination genes in Saccharomyces cerevisiae, RAD52 and RAD54, are induced during meiosis.

The DNA repair and recombination genes of Saccharomyces cerevisiae, RAD52 and RAD54, were transcriptionally induced approximately 10- to 15-fold in sporulating MATa/alpha cells. Congenic MATa/a cells, which did not sporulate, did not show similar increases. Assays of beta-galactosidase activity in strains harboring either a RAD52- or RAD54-lacZ gene fusion indicated that this induction occurred at a time concomitant with a commitment to meiotic recombination, as measured by prototroph formation from his1 heteroalleles.

Role of 131I-metaiodobenzylguanidine in the localization of suspected phaeochromocytomas.

Iodine-131-metaiodobenzylguanidine is a recently-developed radiopharmaceutical agent for adrenal medullary scintigraphy. Twenty-one scans with 131I-metaiodobenzylguanidine were performed in 20 adults with suspected phaeochromocytomas over a four-year period. All patients previously had undergone computed tomographic scans of the abdomen and pelvis.

Older drivers: their night fatal crash involvement and risk.

The 1983 Fatal Accident Reporting System (FARS) data and the Nationwide Personal Transportation Study (NPTS) exposure data were used to describe the major problems in night driving that involved older drivers, aged 65 or more, in fatal crashes and to assess their risk. One of the major findings was that the rate of involvement in fatal crashes in darkness of older drivers was much less than for drivers under the age of 25, but greater overall than for drivers aged 25-64. The rate for older females was much less than for older males.

Effect of Actinomyces pyogenes and gram-negative anaerobic bacteria on the development of bovine pyometra.

Fifteen lactating Holstein cows were used in a trial designed to evaluate the effectiveness of intrauterine inoculation (challenge) of Actinomyces pyogenes (A) alone or in combination with Fusobacterium necrophorum (F) and Bacteroides melaninogenicus (B) to induce pyometra. Cows were assigned to one of five groups: A (n = 3), AB (n = 3), AF (n = 3), ABF (n = 3) or C (control, broth medium alone; n = 3). All cows exhibited estrus 12 or 13 d prior to challenge (Day 0=first day of challenge).

Markers of physical integrity and metabolic viability of the perfused human placental lobule.

1. Peripheral lobules of term placentae obtained from healthy females at Caesarian section were perfused using separate maternal and fetal circulations for 6 h periods under either oxygenated or anoxic conditions. 2.

Screening for thyroid malignancy: the role of fine-needle biopsy.

Cytological examination of the aspirate of fine-needle biopsy is becoming more widely accepted as a screening test for malignancy in thyroid nodules. However, it tends to be used in addition to, rather than instead of, more traditional methods. In this five-year prospective evaluation we performed fine-needle biopsy in 618 euthyroid patients with nodular thyroid enlargement, 86% of whom also underwent radionuclide scans and 55% of whom underwent ultrasound scans.

Karyotyping of yeast strains of several genera by field inversion gel electrophoresis.

Field inversion gel electrophoresis has been used to improve the resolution of the large chromosomes (greater than 1000 kb) present in Saccharomyces kluyveri and in several genera of yeasts other than Saccharomyces cerevisiae, and thus establish more accurately the electrophoretic karyotype of these yeasts. Field inversion gel electrophoresis has also been used to demonstrate the presence of chromosome length polymorphisms in several of the yeasts studied. By Southern blotting techniques the greater degree of relatedness of S.

Generation of homozygosity at the c-Ha-ras-1 locus on chromosome 11p in an adrenal adenoma from an adult with Wiedemann-Beckwith syndrome.

Generation of homozygosity for the human c-Ha-ras-1 locus on the short arm of chromosome #11 (11p) has been demonstrated for an adrenal adenoma from an adult with Wiedemann-Beckwith syndrome (WBS). This is the first demonstration of loss of somatic heterozygosity for a locus on 11p in an adrenal neoplasm and is the first instance where a tumor of any type, from a patient with WBS, shows loss of heterozygosity in this region of the genome. Generation of homozygosity in an adenoma, rather than a carcinoma, demonstrates that this mechanism is an early event in tumorigenesis rather than a late event associated with tumor progression.

Control of venereal disease in infected herds.

Losses from trichomoniasis can be controlled by management and treatment strategies. The best strategy for control of campylobacteriosis is vaccination of cows and bulls with a competent vaccine.

Vesicular adenitis of bulls: A review.

The prevalence of inflammatory disease of the vesicular glands can be as high as 49% in some groups of bulls under common management conditions. Since these bulls are classified as questionable or unsatisfactory potential breeders, this disease can cause significant economic loss to the producer. The current knowledge of the etiology, pathogenesis, diagnosis, treatment, and prevention are discussed.

Characterization of null mutants of the RAD55 gene of Saccharomyces cerevisiae: effects of temperature, osmotic strength and mating type.

RAD55 belongs to a group of genes required for resistance to ionizing radiation, RAD50-RAD57, which are thought to define a pathway of recombinational repair. Since all four alleles of RAD55 are temperature conditional (cold sensitive) for their radiation phenotype, we investigated the phenotype produced by null mutations in the RAD55 gene, constructed in vitro and transplaced to the yeast chromosome. The X-ray sensitivity of these null mutant strains was surprisingly suppressed by increased temperature, osmotic strength of the growth medium and heterozygosity at the mating-type locus.

Analysis of DNA double strand breakage and repair using orthogonal field alternation gel electrophoresis.

Orthogonal field alternation gel electrophoresis (OFAGE) allows separation of DNA molecules in the size range of 200 kb to 3000 kb. These sizes encompass the chromosome sizes of the genome of Saccharomyces cerevisiae. Using this technique, we have found that yeast cells exposed to X-rays generate a smear of DNA fragments corresponding to the products of random, independent double strand breaks, and that the bands corresponding to unbroken chromosomes decrease in intensity in direct proportion to chromosome size.

Morphometric analysis of thyroid cell aspirates.

One hundred and nineteen patients with thyroid nodules underwent fine needle aspiration cytology. Fifty eight were subsequently shown to have multinodular goitre: 36 had a follicular adenoma; 12 follicular carcinoma; and 13 papillary carcinoma on paraffin section. Morphometry performed on the aspirated cells stained by Papanicolaou and Giemsa methods showed significant differences in mean nuclear area and nuclear perimeter between groups of patients with benign thyroid nodules and those with malignant nodules.

Regulation of RAD54- and RAD52-lacZ gene fusions in Saccharomyces cerevisiae in response to DNA damage.

The RAD52 and RAD54 genes in the yeast Saccharomyces cerevisiae are involved in both DNA repair and DNA recombination. RAD54 has recently been shown to be inducible by X-rays, while RAD52 is not. To further investigate the regulation of these genes, we constructed gene fusions using 5' regions upstream of the RAD52 and RAD54 genes and a 3'-terminal fragment of the Escherichia coli beta-galactosidase gene.

A yeast screening system for simultaneously monitoring multiple genetic endpoints.

Mutation, recombination, and mitochondrial deficiencies have been proposed to have roles in the carcinogenic process. We describe a diploid strain of the yeast Saccharomyces cerevisiae capable of detecting this wide spectrum of genetic changes. Strain XD83 can detect forward mutation, back nuclear frameshift and base-pair substitution mutation, nuclear intragenic and intergenic recombination, and mitochondrial forward point mutations and deletions.

Hypothyroidism and Graves' disease after mantle irradiation: a follow up study.

Fifty of 66 patients whose thyroid function had previously been assessed 7-139 months after irradiation for Hodgkin's disease were re-evaluated 35 +/- 3 months later. They could be divided into three groups: those whose thyroid function had been normal in the first study (N = 26), those who had had asymptomatic impaired thyroid reserve (N = 19), and those in whom evidence of Graves' disease had developed (N = 5). The 26 patients who had been euthyroid when first studied had developed significant increases in mean thyroid-stimulating hormone (TSH) levels (basal and following thyrotrophin releasing hormone) without changes in mean free thyroxine index (FTI).

Genealogy of principal strains of the yeast genetic stock center.

We have constructed a genealogy of strain S288C, from which many of the mutant and segregant strains currently used in studies on the genetics and molecular biology of Saccharomyces cerevisiae have been derived. We have determined that its six progenitor strains were EM93, EM126, NRRL YB-210 and the three baking strains Yeast Foam, FLD and LK. We have estimated that approximately 88% of the gene pool of S288C is contributed by strain EM93.

First position wobble in codon-anticodon pairing: amber suppression by a yeast glutamine tRNA.

A 2.4-kb fragment of DNA isolated from the Saccharomyces cerevisiae genome was found to suppress amber mutations when its carrier plasmid was present in high copy number. A 1.

Computer assisted validation of binding assays for sex hormone binding globulin.

Accurate measurement of sex hormone binding globulin (SHBG) by 5 alpha-dihydrotestosterone (DHT) binding assays requires the establishment of acceptable upper and lower limits of labelled DHT binding and the use of optimal quantities of radioinert DHT to displace labelled DHT. A computer assisted binding assay for SHBG is described in which upper and lower binding limits are derived mathematically from analysis of labelled DHT binding to eight concentrations of SHBG in the range 25 to 400 nM. The optimal quantity of radioinert DHT for a given SHBG concentration is also derived from these binding curves.