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A Hilton

Publications and source records attributed to A Hilton.

17 recordsLinked to original sources
PubMed1992

The human Y chromosome: overlapping DNA clones spanning the euchromatic region.

The human Y chromosome was physically mapped by assembling 196 recombinant DNA clones, each containing a segment of the chromosome, into a single overlapping array. This array included more than 98 percent of the euchromatic portion of the Y chromosome. First, a library of yeast artificial chromosome (YAC) clones was prepared from the genomic DNA of a human XYYYY male. The library was screened to identify clones containing 160 sequence-tagged sites and the map was then constructed from this information. In all, 207 Y-chromosomal DNA loci were assigned to 127 ordered intervals on the basis of their presence or absence in the YAC's, yielding ordered landmarks at an average spacing of 220 kilobases across the euchromatic region. The map reveals that Y-chromosomal genes are scattered among a patchwork of X-homologous, Y-specific repetitive, and single-copy DNA sequences. This map of overlapping clones and ordered, densely spaced markers should accelerate studies of the chromosome.

Base Sequence↗
PubMed1992

The human Y chromosome: a 43-interval map based on naturally occurring deletions.

A deletion map of the human Y chromosome was constructed by testing 96 individuals with partial Y chromosomes for the presence or absence of many DNA loci. The individuals studied included XX males, XY females, and persons in whom chromosome banding had revealed translocated, deleted, isodicentric, or ring Y chromosomes. Most of the 132 Y chromosomal loci mapped were sequence-tagged sites, detected by means of the polymerase chain reaction. These studies resolved the euchromatic region (short arm, centromere, and proximal long arm) of the Y chromosome into 43 ordered intervals, all defined by naturally occurring chromosomal breakpoints and averaging less than 800 kilobases in length. This deletion map should be useful in identifying Y chromosomal genes, in exploring the origin of chromosomal disorders, and in tracing the evolution of the Y chromosome.

Base Sequence↗
PubMed1992

Replacement of cisplatin with carboplatin in combination chemotherapy against ovarian cancer: long-term treatment results of a study of the Gynaecological Cancer Cooperative Group of the EORTC and experience at The Netherlands Cancer Institute.

Carboplatin-based chemotherapy has been evaluated in three studies of ovarian cancer patients. In the first, combination cisplatin and carboplatin plus doxorubicin/hexamethylmelamine/cyclophosphamide were compared as first-line treatment of ovarian cancer in 341 women with stage IIB to IV disease. There were no observed differences in results between the two treatment groups. In the second study, conventional doses of intravenous carboplatin (350 mg/m2, given on day 1) plus oral cyclophosphamide (100 mg/m2 days 2 to 6) were given to late-relapsing patients (12 to 72 months) previously treated with cisplatin. Mature data showed a 55% overall response rate, acceptable toxicity, and an absence of additive neurotoxicity. Finally, 65 patients with refractory disease or in early relapse after cisplatin therapy (within 12 months) were treated with high-dose carboplatin (800 mg/m2). Toxicity was severe, but the 45% combined response rate was considered encouraging and worthy of further evaluation. It was concluded that carboplatin is an appropriate replacement for cisplatin in the treatment of ovarian cancer.

Adult↗
PubMed1986

Ifosfamide by bolus as treatment for advanced non-small cell lung cancer.

Ifosfamide at 5 g/m2 was given as a bolus to 48 patients with advanced progressing non-small cell lung cancer. Mesna (5 g/m2) was also given with the ifosfamide, both over 30 min. Further mesna was then given p.o. (3 g/m2) at 4, 8, and 12 h. If oral mesna was not acceptable then one or, if necessary, two 4-h to 6-h infusions (3 g/m2) were administered. A maximum of six courses at 3-weekly intervals was prescribed. A total of 174 courses was administered, and oral mesna was given during 64 courses: discharge was considered possible within 8-10 h after 55% of courses. Haematological toxicity was mild and no renal dysfunction was noted. Two patients became drowsy shortly after ifosfamide, but recovered 24-36 h later. The objective response rate was 29%, with one complete responder. A further 31% of patients (symptomatic responders) with stable disease symptomatically improved after the chemotherapy, by 20 or more points on the Karnofsky scale. The median survival was 5 months for the whole group, and 8 months each for the objective and symptomatic responder groups. Most patients' Karnofsky and respiratory scores improved with the chemotherapy. Ifosfamide with mesna can be given by short infusions, and the mesna given p.o. prevents any urothelial toxicity. Further exploration of short-infusion ifosfamide and mesna therapy would reduce hospitalization and allow for day-case regimens.

Adult↗
PubMed1986

Translational control in murine hepatitis virus infection.

High multiplicity infection of mouse fibroblast L-2 cells with mouse hepatitis virus (MHV) resulted, within 6 h, in a decline in total protein synthesis to about 7% of that observed in uninfected cells. The amount of intracellular total translatable RNA, however, increased approximately threefold, as a result of the accumulation of virus-encoded mRNAs. MHV-infected cells could be superinfected with vesicular stomatitis virus, demonstrating that MHV infection did not irreversibly alter the cellular translational machinery to the exclusion of non-MHV mRNAs. Comparative polysome analysis from MHV-infected and uninfected L-2 cells showed that MHV infection resulted in an increase in single 80S ribosomes and in a shift from longer to shorter polysomes. These observations suggest first, that MHV infection inhibits total protein synthesis at a very early stage, as evidenced by the increase in 80S ribosomes, and, second, that the increased number of viral mRNAs produced after infection compete with cellular mRNAs for cellular ribosomes. In vitro translation of RNA extracted from MHV-infected and mock-infected cells suggested that levels of cellular mRNAs were decreased after infection. This suggestion was confirmed by demonstrating the loss of cellular actin mRNA, using a radiolabelled cDNA probe, as a consequence of MHV infection.

Animals↗
PubMed1985

Attenuation of murine coronavirus infection by ammonium chloride.

Ammonium chloride at a concentration of 20 mM delayed by 4-5 hr the production of virus progeny in mouse L-2 cells infected at high multiplicity with mouse hepatitis virus (MHV). This delay was seen in the production of both intracellular and extracellular virus. However, the final titers were similar to those produced by MHV-infected cells maintained in normal medium. The manifestation of virus-induced cell fusion was similarly found to be delayed, but not otherwise decreased in severity, when ammonium chloride was present in the culture medium. Ammonium chloride caused similar delays in production of virus-specific, positive-sense RNAs and of viral polypeptides. The relative proportions and apparent molecular weights of viral RNAs and polypeptides were similar to those found in MHV-infected cells cultured in normal medium. In vitro translation of endogenously produced viral RNAs in cell extracts, prepared from MHV-infected cells, was not inhibited by ammonium chloride. Thus, ammonium chloride has no specific, inhibitory effect on viral protein synthesis. Ammonium chloride did not reduce the number of virus-infected cells in culture, as monitored by infectious center assay. Analysis of early events in MHV infection showed that ammonium chloride did not affect adsorption or internalization of MHV by L-2 cells. However, the subsequent eclipse phase, as monitored by decline in infectivity of internalized virus inoculum proceeded less efficiently in the presence of ammonium chloride. On the basis of the known inhibitory effects of ammonium chloride on lysosomal/endosomal functions, the results suggest an endosomal mechanism of MHV uncoating. Thus the primary effect of ammonium chloride on MHV infection of L-2 cells is to attenuate virus uncoating, thereby chronologically displacing all subsequent virus-encoded functions.

Ammonium Chloride↗