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Biomedical subjects

M J Clancy

Publications and source records attributed to M J Clancy.

At least 55 records · Page 3Linked to original sources
PubMed1989

Characterization and localization of the sporulation glucoamylase of Saccharomyces cerevisiae.

Glucoamylase (SGA) was purified approximately 250-fold from sporulating Saccharomyces cerevisiae cells. The partially purified enzyme was active against glycogen, starch, maltotriose and maltose. It exhibited maximum catalytic activity against glycogen at pH 5.5. The enzyme appears to be glycosylated, because it bound to lentil-lectin Sepharose. SGA was expressed in vegetatively growing cells under the control of the GAL1 promoter, and the cellular location of the enzymatic activity determined by fractionation techniques. SGA was preferentially recovered in fractions which were enriched for the vacuolar hydrolases, carboxypeptidase Y and alpha-mannosidase.

Carbohydrate Conformation↗
PubMed1989

Dependence of inessential late gene expression on early meiotic events in Saccharomyces cerevisiae.

SPR3 is one of at least nine genes which are expressed in sporulating Saccharomyces cerevisiae cells at the time of meiosis I. We show below that strains homozygous for null alleles of SPR3 are capable of normal meiosis and the production of viable ascospores. We have also monitored SPR3 expression in a series of strains that are defective in meiotic development, using an SPR3:lacZ fusion carried on a single copy plasmid. beta-Galactosidase activity occurred at wild-type levels in diploid strains homozygous for mutations in spo13, rad50, rad57 and cdc9, but was greatly reduced in strains carrying cdc8 or spo7 defects. We conclude that SPR3 expression is a valid monitor of early meiotic development, even though the gene is inessential for the sporulation process.

Gene Expression Regulation↗
PubMed1989

The diagnosis of ectopic pregnancy in an accident and emergency department.

The correct diagnosis was initially suspected in 32 (53%) of 60 patients with ectopic pregnancy who attended an accident and emergency department. Incorrect diagnoses were made because ectopic pregnancy was not considered or because relevant symptoms and signs were missed or misinterpreted. Three patients had been 'sterilized'. Twenty-four patients (40%) had abdominal pain or vaginal bleeding for more than 1 week before attending. Fever and leucocytosis were wrongly attributed to pelvic infection. Pregnancy tests were positive in 56% of the patients tested.

Adolescent↗
PubMed1989

Answer please. Blount's disease: tibia vara.

Infantile tibia vara, although uncommon compared to normal physiologic bowing, is significant due to the resultant progressive deformities if not diagnosed early. The key radiographic finding is medial tibial metaphyseal beaking and fragmentation. Although the etiology is unclear, it appears to be an acquired growth disturbance of the proximal medial tibial epiphysis, ossification center, and metaphysis rather than any type of avascular necrosis. The Langenskiöld six-stage classification is useful for the diagnostic, prognostic, and treatment staging of the disease. The adolescent form is less common and less severe with only slight irregular thickening of the physis present on radiograph. The MDA appears to be the most reproducible method for measuring angular deformities in both variants of the disease. Treatment of the infantile stages I or II consists of observation and bracing. Stage III or IV disease in children over age 3 years with more than 5 degrees of varus angulation should be treated with corrective valgus osteotomy. Stages V or VI may require repeated surgical treatment with multiple osteotomies and possible contralateral epiphysiodesis. The adolescent form frequently requires surgery when there is significant physical impairment related to the severe genu varum.

Child↗
PubMed1989

Total hip replacement and antithrombotic prophylaxis.

British orthopaedic surgeons were surveyed to assess the practice of prophylaxis against thromboembolism in patients undergoing total hip replacements. Of 690 surgeons, 348 (50.4%) do not routinely use pharmacological prophylaxis (190 use no prophylaxis while 158 use a mechanical form of prophylaxis), 289 (41.9%) surgeons use a single pharmacological agent (with or without a mechanical form of prophylaxis), and the remaining 53 (7.7%) use two or more pharmacological agents.

Antithrombins↗
PubMed1987

Transcriptional regulation of sporulation genes in yeast.

The relative transcription rates of three sporulation-regulated genes of yeast (SPR1, SPR2 and SPR3) were determined at intervals during sporulation, using a filter binding assay. The binding of in vivo labeled RNA to the corresponding DNAs increased 3- to 12-fold at the time of meiosis I, in parallel with the accumulation of the SPR transcripts. SPR1 and SPR3 mRNA abundance increased from less than 0.7 to 130 and 90 copies per cell, respectively, between the time of shift to sporulation medium and the initiation of spore formation. This represented a 150-to 200-fold increase in the steady-state levels of these RNAs. Similarly, the levels of beta-galactosidase present in sporulating cells harboring fusions between SPR3 and Escherichia coli lacZ increased at least 700-fold. We conclude that SPR1, SPR2 and SPR3 transcription is modulated during sporulation, possibly in response to earlier events in the process.

Cloning, Molecular↗
PubMed1987

The formulation of buffers and media for enzyme histochemistry.

Buffer solutions and incubating media for enzyme histochemistry are discussed in terms of pH, ionic strength and buffering capacity. A specially written program is presented. This program enables (i) buffers and media of known pH and ionic strength to be formulated; (ii) the ionic strength of a buffer solution of known molarity, and (iii) the thermodynamic acid dissociation constant of a buffer substance, to be calculated.

Buffers↗
PubMed1986

The effects of anabolic agents and breed on the fibers of the longissimus muscle of male cattle.

Sample of longissimus muscle were taken from carcasses of steers, steers implanted with anabolic agents and bulls of Friesian and Charolais X Friesian breeds of cattle. Percent and mean cross-sectional areas (CSA) of three myofiber types (beta R, alpha R and alpha W) were determined. The percentage of beta R myofibers did not vary significantly with treatment. The implanted steers had 26% more alpha R and 8% less alpha W myofibers than the untreated steers, while the bulls had 33% more alpha R and 20% less alpha W myofibers than the implanted steers (P less than .001). In the implanted steers the mean CSA of the beta R myofibers was significantly greater than that of the untreated steers, but did not differ from that of the bull. The mean CSA of the alpha R myofibers increased considerably with treatment, but only that of the bull was significantly greater than that of the untreated steers. The mean CSA of the alpha W myofibers in the implanted steers was identical with that of the untreated steers and significantly smaller than that of the bulls. In comparison to the untreated steers, significant hypertrophy of all three myofiber types occurred in bulls. These findings demonstrate a significant increase in the oxidative capacity of the longissimus when the levels of both endogenous and exogenous anabolic agents are increased. They are also consistent with the greater efficiency of deposition of protein obtained with implanted steers and bulls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Sporulation-regulated genes of Saccharomyces cerevisiae.

We have characterized 46 hybrid phage which hybridize preferentially to mRNA from sporulating cells. Cross-hybridization experiments demonstrate that 27 distinct SPR (Sporulation regulated) sequences are represented among these phage. The SPR genes can be grouped into three classes: early, middle, and late. The early class shows an accumulation of transcripts soon after transfer to sporulation medium and continues to accumulate RNA throughout sporulation. Transcripts of the middle class increase in level at about the time of DNA synthesis, rise rapidly in abundance until meiosis II, then accumulate more slowly for at least the next 3 h. Late gene transcripts begin to accumulate at about the time of meiosis I, increase 10- to 20-fold in the next 2 h, then remain constant in late sporulating cells.

Bacteriophage lambda↗
PubMed1983

Isolation of genes expressed preferentially during sporulation in the yeast Saccharomyces cerevisiae.

A library of Saccharomyces cerevisiae DNA in the vector lambda Charon 28 was probed for sequences complementary to cDNA made from poly(A)+ RNA isolated from the well-sporulating yeast strain AP1 a/alpha. The RNA was isolated from cells that had been incubated 7, 9, 11, and 13 hr in sporulation medium. DNA complementary to poly(A)+ RNA from alpha/alpha(nonsporulating) AP1 was used as a control, and 46 bacteriophage that gave a stronger response with a/alpha cDNA than with alpha/alpha cDNA were obtained in a screening of three yeast genomes worth of DNA. Two of the bacteriophage appeared to contain a/alpha-specific genes, in that they hybridized to cDNA from vegetative a/alpha RNA. The rest appeared to correspond to a/alpha genes expressed preferentially during sporulation. Restriction endonuclease analysis of four of the cloned sequences revealed a single major region of transcription in each; these regions ranged in size from 2.5 to 4.0 kilobases. RNA blot analysis showed that, in three of the four cases, transcripts of two different sizes were homologous to the cloned sequence. In all four cases, the homologous transcripts appeared at about 7 hr and were decreasing in amount by 13 hr. These results provide evidence for transcriptional control of genes expressed during sporulation and for at least one group of genes that is turned on at about the time of meiosis I in sporulation.

Base Sequence↗
PubMed1982

Localization of proteins in the inner and outer membranes of Caulobacter crescentus.

Cytoplasmic and outer membranes of Caulobacter crescentus were separated by isopycnic sucrose gradient centrifugation into two peaks with buoyant densities 1.22 and 1.14 g/cm3. These peaks were identified as outer and cytoplasmic membranes by the enrichment of malate dehydrogenase and NADH oxidase in the lower density peak and the presence of flagellin, a cell surface protein, in the heavier peak. The identity of the heavier peak as outer membrane was confirmed by labeling of cells with diazotized [35S]sulfanilic acid, a reagent that does not penetrate intact cells. Under these conditions only outer membrane proteins were substituted by the sulfanilic acid. The distribution of proteins between the cytoplasmic and outer membranes were examined by the analysis of [35S]methionine-labeled membranes by SDS-polyacrylamide and two-dimensional gel electrophoresis. These results showed that the inner and outer membranes contain approximately equal numbers of proteins, and that the distribution of these proteins between the two layers is highly asymmetric. Although many of the proteins could be assigned to one or the other membrane fraction, a number of the outer membrane proteins in the 32 000-100 000 molecular weight range frequently contaminate the inner membrane fractions. The implications of these results for membrane isolation and separation in C. crescentus are discussed.

Bacteria↗
PubMed1982

Developmental regulation of a sporulation-specific enzyme activity in Saccharomyces cerevisiae.

An alpha-glucosidase activity (SAG) occurs in a/alpha Saccharomyces cerevisiae cells beginning at about 8 to 10 h after the initiation of sporulation. This enzyme is responsible for the rapid degradation of intracellular glycogen which follows the completion of meiosis in these cells. SAG differs from similar activities present in vegetative cells and appears to be a sporulation-specific enzyme. Cells arrested at various stages in sporulation (DNA replication, recombination, meiosis I, and meiosis II) were examined for SAG activity; the results show that SAG appearance depends on DNA synthesis and some recombination events but not on the meiotic divisions.

Cycloheximide↗
PubMed1980

Properties of polyadenylate-associated ribonucleic acid from Saccharomyces cerevisiae ascospores.

Bulk ribonucleic acid (RNA) was isolated from mechanically disrupted ascospores of Saccharomyces cerevisiae. After two passes over an oligo (dT10) cellulose column, the portion which bound, called poly(A)(+), was characterized. It is heterodisperse in size with a mean molecular weight of approximately 4 X 10(5), but contains some species as large as 7 X 10(5). The base composition is similar to vegetative poly(A)(+) RNA. The polyadenylate segment is also heterogenous in size, ranging from 90 to 20 bases in length, with a peak at approximately 60 nucleotides in length. Pulse-labeling of asci with [3H-methyl]methionine yields two "caps," 7-methyl guanosine-5'-triphosphoryl-5'-adenosine (or guanosine) identical to that found in vegetative poly(A)(+) RNA. The poly(A)(+) RNA in spores is found in polyribosomes which are, on the average, smaller than vegetative ones. Long-term labeling studies indicate that the fraction of poly(A)(+) RNA in spores is similar to that in vegetative cells.

Base Sequence↗