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Biomedical subjects

H Bates

Publications and source records attributed to H Bates.

At least 19 recordsLinked to original sources
PubMed2006

The use of time-series data in the assessment of macrobenthic community change after the cessation of sewage-sludge disposal in Liverpool Bay (UK).

Sewage sludge was disposed of in Liverpool Bay for over 100 years. Annual amounts increased from 0.5 million tonnes per annum in 1900 to approximately 2 million tonnes per annum by 1995. Macrofauna and a suite of environmental variables were collected at a station adjacent to, and a reference station distant from, the disposal site over 13 years, spanning a pre- (1990-1998) and post- (1999-2003) cessation period. Univariate and multivariate analyses of the time-series data showed significant community differences between reference and disposal site stations and multivariate analyses revealed station-specific community development post-disposal. Temporal variability of communities collected at the disposal station post-cessation was higher than during years of disposal, when temporally stable dominance patterns of disturbance-tolerant species had established. Alterations of community structure post-disturbance reflected successional changes possibly driven by facilitation. Subtle faunistic changes at the Liverpool Bay disposal site indicate that the near-field effects of the disposal of sewage sludge were small and therefore could be considered environmentally acceptable.

Analysis of Variance↗
PubMed2001

Identification and characterisation of the Drosophila homologue of the yeast Uba2 gene.

We have identified the Drosophila uba2 protein (dUba2). Analysis of the amino acid composition reveals similarity with both the mammalian (47% identity) and yeast (31% identity) homologues. dUba2 is present throughout the Drosophila life cycle but is most abundant during stages of proliferation. The protein is nucleoplasmic throughout much of the cell cycle, however it is lost from the nucleus during mitosis. The DUba2 localisation in the nucleoplasm is not uniform but is observed as concentrated patches reminiscent of the staining patterns seen for other proteins from this group. The nature of these sites is not clear, however the failure of dUba2 to localise to the sites of chorion amplification in ovaries suggests that they are not sites of ongoing DNA replication.

Amino Acid Sequence↗
PubMed2001

The Drosophila Dpit47 protein is a nuclear Hsp90 co-chaperone that interacts with DNA polymerase alpha.

Hsp90 is gaining increasing importance as a protein involved in controlling the normal functioning of the cell. To do this it apparently interacts with a battery of co-chaperone proteins that are involved in both substrate recognition and the progression of the Hsp90 catalytic pathway. In this report we have identified the Drosophila Dpit47 protein (DNA polymerase interacting tpr containing protein of 47 kDa) through its interaction with the DNA polymerase alpha. This protein is a predominantly nuclear protein, which forms a tight and stoichiometric interaction with Hsp90 and shows interaction with Hsp70. It also has substantial homology to other known Hsp90 co-chaperones, e.g. CNS1 and hop1, making it likely that this protein also functions as an Hsp90 co-chaperone. The interaction with the DNA polymerase alpha is not related to the special situation in early embryos where there are large amounts of maternal protein stockpiles of the polymerase, as it occurs to the same level in early and late embryos and also in proliferating cell culture. However, it does not occur in quiescent cells, making it likely that the protein is related to proliferation. This is also consistent with Dpit47 expression being higher in proliferating cells. The interaction between the Dpit47 and the polymerase takes place predominantly in the nucleoplasm, and seems to involve several subunits of the polymerase in comparable amounts, making it unlikely that it is solely required for the assembly of the polymerase complex. The polymerase can also be seen to interact with Hsp90, and the interaction between Dpit47 and the polymerase is increased by the specific Hsp90 inhibitor geldanamycin. This suggests that a complex of the Dpit47, Hsp90 and DNA polymerase exists in the cell. The interaction between DNA polymerase alpha and Dpit47 completely inhibits the activity of the polymerase. These results suggest that Hsp90 acts as a chaperone for DNA polymerase alpha and that this interaction is mediated through the novel co-chaperone Dpit47. This provides the first suggestion of a role for chaperones in DNA replication in higher eukaryotes.

Amino Acid Motifs↗
PubMed2000

Importin-alpha3 is required at multiple stages of Drosophila development and has a role in the completion of oogenesis.

The Drosophila importin-alpha3 gene was isolated through its interaction with the large subunit of the DNA polymerase alpha in a two-hybrid screen. The predicted protein sequence of Importin-alpha3 is 65-66% identical to those of the human and mouse importin-alpha3 and alpha4 and 42.7% identical to that of Importin-alpha2 (Oho31/Pendulin), the previously reported Drosophila homologue. Both Importin-alpha3 and Importin-alpha2 interact with similar subsets of proteins in vitro, one of which is Ketel, the importin-beta homologue of Drosophila. importin-alpha3 is an essential gene, whose encoded protein is expressed throughout development. During early embryogenesis, Importin-alpha3 accumulates at the nuclear membrane of cleavage nuclei, whereas after blastoderm formation it is characteristically found within the interphase nuclei. Nuclear localisation is seen in several tissues throughout subsequent development. During oogenesis its concentration within the nurse cell nuclei increases during stages 7-10, concomitant with a decline in levels in the oocyte nucleus. Mutation of importin-alpha3 results in lethality throughout pupal development. Surviving females are sterile and show arrest of oogenesis at stages 7-10. Thus, Importin-alpha3-mediated nuclear transport is essential for completion of oogenesis and becomes limiting during pupal development. Since they have different expression patterns and subcellular localisation profiles, we suggest that the two importin-alpha homologues are not redundant in the context of normal Drosophila development.

Amino Acid Sequence↗
PubMed1991

Cytologic assessment of tumor cell kinetics: applications of monoclonal antibody Ki-67 to fine-needle aspiration smears.

Rates of tumor-cell proliferation often provide prognostic information about a given neoplasm. Previously available methods for accessing cell kinetics are time consuming and expensive, and often require special equipment or radioactive reagents. Monoclonal antibody Ki-67 binds a nuclear antigen expressed in proliferating but not in resting cells. We studied Ki-67 immunostaining of fine-needle aspiration smears from 40 benign and malignant masses. Labeling indices ranged from 0 (thyroid follicular adenoma) to 75 percent (pulmonary oat-cell carcinoma). Frozen section immunostaining (11 cases) and flow cytometric assessment of cell proliferation (8 cases) were in good agreement with Ki-67 labeling indices on smear material. We suggest that this method provides a rapid, inexpensive, and dependable means of assessing tumor-cell kinetics in cytologic preparations.

Antibodies, Monoclonal↗
PubMed1991

Mutagenic DNA repair in Escherichia coli. XIX. On the roles of RecA protein in ultraviolet light mutagenesis.

An experimental system was used in which His+ mutations induced by ultraviolet light (UV) arise from non-photo-reversible photoproducts whereas lethality is largely determined by photoreversible photoproducts. By exposing a strain with a deletion through recA to light immediately after UV, it was possible to examine mutagenesis under conditions where survival was not significantly different from 100%. No UV mutagenesis was seen in the absence of RecA protein even though the rest of the SOS system was fully expressed due to the presence of a defective LexA repressor and the active carboxy-terminal fragment of UmuD was present as a result of an engineered plasmid-borne gene. We conclude that RecA protein has a third essential function if UV mutagenesis is to be detected in excision-deficient-bacteria. Another experiment showed that in exerting this function RecA protein does not need activation by pyrimidine dimers elsewhere on the genome, in contrast to its protein-cleavage mediation functions with LexA and UmuD proteins. RecA1730 protein blocked UV mutagenesis unless delayed photoreversal was given showing that the third function of RecA protein is not in the misincorporation step. It is therefore most likely to be in the bypass step where UmuD' and UmuC are postulated to act, although the possibility cannot be excluded that RecA protein is required for some other survival function distinct from translesion synthesis.

Alleles↗
PubMed1990

Mutagenic DNA repair in Escherichia coli. XVIII. Involvement of DNA polymerase III alpha-subunit (DnaE protein) in mutagenesis after exposure to UV light.

UV light was unable to induce rifampicin-resistant mutations at 43 degrees C in Escherichia coli ER11 dnaE486. Although DnaE486 gene product is inactive at 43 degrees C, these bacteria contain the pcbA1 mutation which allows DNA replication provided DNA polymerase I is functional. The experiments were carried out under conditions where full expression of rifampicin-resistant mutations could occur so that the lack of induced mutations cannot be ascribed to an effect of incubation at 43 degrees C on mutation expression. UV-mutability at 43 degrees C was restored by the presence of the dnaE+ allele on a plasmid. It is concluded that functional DnaE protein is essential for UV mutagenesis. The dnaE486 mutation also blocked the induction at 43 degrees C of mutations induced by UV plus delayed photoreversal, a procedure that has been postulated to reflect an early misincorporation step in the UV mutagenic process.

DNA Polymerase III↗
PubMed1989

Spontaneous and UV-induced mutations in Escherichia coli K-12 strains with altered or absent DNA polymerase I.

The induction of mutations to valine resistance and to rifampin resistance occurs after UV irradiation in bacteria carrying a deletion through the polA gene (delta polA), showing that DNA polymerase I (PolI) is not an essential enzyme for this process. The PolI deletion strain showed a 7- to 10-fold-higher spontaneous mutation frequency than the wild type. The presence in the deletion strain of the 5'----3' exonuclease fragment on an F' episome caused an additional 10-fold increase in spontaneous mutation frequency, resulting in mutation frequencies on the order of 50- to 100-fold greater than wild type. The mutator effect associated with the 5'----3' exonuclease gene fragment together with much of the effect attributable to the polA deletion was blocked in bacteria carrying a umuC mutation. The mutator activity therefore appears to reflect constitutive SOS induction. Excision-proficient polA deletion strains exhibited increased sensitivity to the lethal effect of UV light which was only partially ameliorated by the presence of polA+ on an F' episome. The UV-induced mutation rate to rifampin resistance was marginally lower in delta polA bacteria than in bacteria carrying the polA+ allele. This effect is unlikely to be caused by the existence of a PolI-dependent mutagenic pathway and is probably an indirect effect caused by an alteration in the pattern of excision repair, since it did not occur in excision-deficient (uvrA) bacteria. An excision-deficient polA deletion strain possessed UV sensitivity similar to that of an isogenic strain carrying polA+ on an F' episome, showing that none of the functions of PolI are needed for postreplication repair in the absence of excision repair. Our data provide no evidence for a pathway of UV mutagenesis dependent on PolI, although it remains an open question whether PolI is able to participate when it is present.

DNA Polymerase I↗
PubMed1989

Polymerases and UV mutagenesis in Escherichia coli.

Evidence for and against the involvement of the known nucleic acid polymerases in UV mutagenesis in Escherichia coli is reviewed. There is no evidence that rules out the participation of any of them when they are present but only one, the alpha subunit of DNA polymerase III holoenzyme (polC gene product) has been shown to be essential. It is argued that the PolC protein that functions in UV mutagenesis may not be immediately recognizable as one of the normal cellular polymerases or polymerase complexes.

Bacterial Proteins↗
PubMed1985

Testosterone receptors in corpora cavernosa of penis.

Despite existing information that most impotent patients have normal serum testosterone, testosterone is still used frequently in the treatment of impotence. In 11 patients who underwent penile implantation, we measured the presence of testosterone receptors in the corpora cavernosa. An average value of 1.82 fmol/mg of protein cytosol was found in this group of patients. This value is too low to obtain any significant improvement in erectile function following testosterone application. Testosterone hypogonadism will likely remain the only indication in which testosterone application might improve organically triggered impotence.

Adult↗
PubMed1984

Cholinergic receptors in corpora cavernosa.

In a group of 13 patients who underwent penile surgery, a small amount of cavernosal tissue was removed and examined for content of cholinergic receptors. Three patients did not display any amount of cholinergic receptors. Values in the other 10 patients ranged from 34 to 136 femtomols. In another group of 61 impotent patients with some degree of preserved erectile capacity, cholinergic stimulation was administered to the patients and the response monitored. Preliminary data displayed improved erectile capacity in 41 per cent. Further studies are needed to identify impotent patients who might respond favorably to cholinergic stimulation.

Adult↗
PubMed1984

Urinary retention in female patients induced by adenocarcinoma of urethra.

Acute urinary retention in middle-aged females is an infrequent occurrence; therefore, when such a patient presents to the urologist, an aggressive diagnostic evaluation is warranted. Carcinoma of the urethra might be the underlying pathologic process causing urinary retention. Herein, we present 2 cases of acute urinary retention triggered by adenocarcinoma of the urethra. In 1 patient the diagnosis was delayed due to severe superimposed infection which responded poorly to medication. Anterior exenteration and radiotherapy were used in the management of both patients.

Adenocarcinoma↗
PubMed1982

Paternal effects of ethanol in the long-evans rat.

Ten male Long-Evans rats were given 20% v/v ethanol in the drinking water for 60 consecutive days. Ten other males were given distilled water and served as controls. Each male was then allowed to mate with three virgin female Long-Evans rats, once per week for three consecutive weeks. The males were necropsied after the third mating, the females were killed on d 20 of gestation, and the offspring were examined for parameters of fetal growth, skeletal ossification, and soft-tissue anomalies. Ethanol caused testicular weight reductions and gross testicular atrophy in 1 of 10 males. Five matings of alcoholic male rats proved infertile. Total embryonic deaths (resorptions and preimplantation loss) were increased by ethanol, while implantations and litter size were significantly decreased. Fetuses fathered by alcoholic male rats were malformed: 55% had soft-tissue anomalies (microcephalus, microphthalmia, cranial fissure, and hydronephrosis). Litter weight and average pups weights were also reduced by paternal ethanol consumption. No recovery in reproductive function was evident over the 21-d post-ethanol mating period.

Animals↗