Search PubMed⌕ Search

Biomedical subjects

J R Young

Publications and source records attributed to J R Young.

At least 19 recordsLinked to original sources
PubMed1992

Restriction mapping of the genome of the protozoan parasite Theileria parva.

We have used a modified linking clone strategy and pulsed-field gel electrophoresis to derive a map of the 29 Sfi I and 4 Not I sites in the 10 million base pair genome of the protozoan parasite Theileria parva. This was achieved in the absence of classical genetic information. The map reveals four chromosomes. Several genes, including those for parasite antigens, have been located on the map, as has the single locus carrying the major repetitive sequence in this organism. The map forms the basis for a study of sexual recombination in T. parva, which will be of importance in the application of present methods of immunization. Aspects of the mapping strategy may be useful in the study of other small eukaryotic genomes.

Animals↗
PubMed1992

A common ancestor of the mammalian transcription factors TCF-1 and TCF-1 alpha/LEF-1 expressed in chicken T cells.

Several mammalian T cell-specific transcription factors have been cloned recently. Two of these, TCF-1 and TCF-1 alpha/LEF-1, display a moderate level of overall sequence similarity, and contain virtually identical versions of a novel type of DNA-binding domain, the HMG box. To study evolutionary aspects of the TCF transcription factors in relation to lymphoid differentiation, we have isolated chicken TCF clones from a spleen cDNA library. Low-stringency screening with human probes as well as a polymerase chain reaction-aided strategy resulted in the cloning of a single chicken TCF (chTCF) gene. Sequence comparison revealed that chTCF contained a TCF-1 alpha-like N terminus, and a TCF-1-like C terminus. Furthermore, TCF-1 and TCF-1 alpha were more homologous to chTCF than to each other. We postulate that chTCF is the direct descendant of a single ancestral gene, which has been duplicated in mammals to yield TCF-1 and TCF-1 alpha.

Amino Acid Sequence↗
PubMed1992

Draffin and his rods.

Draffin's rods or bipods are now a well-known, internationally accepted ENT instrument. Before their invention in 1951, the attendant anaesthetist or nurse was obliged to support the mouthgag during tonsillectomy. Research into the life of their originator, David Alexander Draffin, reveals that in addition to his evident design skills, he was a surgeon of courage, wit and great charm.

Anesthesiology↗
PubMed1991

Identification of expressed bovine class I MHC genes at two loci and demonstration of physical linkage.

A cDNA library prepared from lymphocytes of a cow (E98), homozygous at major histocompatibility complex (MHC) loci (BoLA phenotype w10, KN104), was screened with a bovine MHC class I probe. Of the cDNA clones isolated, two, (2.1 and 5.1) were selected and showed divergence at both 5' and 3' termini. E98 DNA was digested with rare-cutter enzymes (Sfi I, Mlu I, Not I, and Cla I) and fragments were size-separated by field inversion gel electrophoresis (FIGE). Hybridization with an entire class I cDNA probe revealed multiple fragments generated by each enzyme. When the 3' untranslated regions (UT) of 2.1 and 5.1 were used as probes, only one fragment was revealed in each digested sample, showing locus specificity of these probes in cattle. Further, DNA of transfected mouse fibroblasts L4 (expressing KN104) and L10 (expressing w10) hybridized to the 3'UT regions of clones 2.1 and 5.1, respectively. Northern blot analysis of the mRNA of the L4 and L10 transfected cells provided further evidence that the cDNA clones 2.1 and 5.1 code for the BoLA-KN104 and BoLA-w10 class I molecules respectively, and thus these represent the products of two different genes. A long range physical mapping of the BoLA-w10 and KN104 genes was performed using FIGE analysis of DNA of an homozygous and an heterozygous animal. This analysis revealed that the BoLA-w10 and KN104 genes are separated by not more than 210 kilobases (kb) and that they are components of a multigene family spanning 1550 kb. As the w10 gene is at the BoLA-A locus we assign the KN104 gene to a B locus.

Animals↗
PubMed1991

Agarose entrapment method for the production of SfiI linking library for Theileria parva.

We have developed a simple method for isolation of SfiI linking clones from a eukaryotic genomic DNA. The method involves the physical separation of the small proportion of plasmids in a plasmid genomic library that are linearized by SfiI digestion, from the bulk of molecules that remain circular, by ordinary electrophoresis through high-percentage gels of SeaPlaque agarose. Following the isolation of linearized molecules, their recircularization, and introduction into Escherichia coli, 55% of recovered plasmids contained inserts of the expected size, and 73% of these had SfiI sites. This represented a 25-fold enrichment of linking clones expected to be present at a frequency of 1/60 in the original library of 4- 6-kb fragments of genomic DNA of the protozoan parasite Theileria parva. This approach is rapid and obviates the need for introduction of a selectable marker. It is uniquely appropriate for linking clones spanning SfiI sites as this enzyme leaves degenerate 3' overhanging ends that preclude the direct ligation into vector sites required by most alternative strategies, but that favor the recircularization reactions used here.

Animals↗
PubMed1991

Unusual hyperechoic ultrasound appearance of testicular Leydig cell tumour.

Patients with a testicular mass are usually investigated by ultrasound and the ultrasound appearances have been correlated with the histology. The authors describe two patients with Leydig cell tumours. The first had bilateral tumours which although histologically typical of Leydig cell tumours, had differing ultrasound appearances, one with a previously unreported hyperechoic appearance. The second patient had an impalpable tumour with similar ultrasound appearances to those previously described. The paper illustrates the difficulty of giving an accurate diagnosis of solid testicular lesions and also shows that the previously described appearance of Leydig cell tumour is not pathognomonic.

Adult↗
PubMed1991

Mammographically guided ultrasound: a new technique for assessment of impalpable breast lesions.

A new technique for the assessment and localization of breast lesions is described. The position of a lesion is identified mammographically using a fenestrated compression plate. This allows access for an ultrasound probe directly over the lesion. This technique has proved valuable in the assessment of breast lesions and a simple inexpensive, reliable method of localization. We give a preliminary report of our results.

Breast Diseases↗
PubMed1991

Safety and efficacy of thrombolytic therapy for superior vena cava syndrome.

The experience at the Cleveland Clinic from 1982 to 1990 using thrombolytic therapy for superior vena cava (SVC) syndrome was retrospectively reviewed. Sixteen patients, 11 of whom had indwelling central venous catheters, were treated with either urokinase (n = 11) or streptokinase (n = 5). Either urokinase (4,400 U/kg bolus followed by 4,400 U/kg/h) or streptokinase (250,000 U bolus followed by 100,000 U/h) was used, and venograms were performed before and after. Overall, 56 percent of patients had complete clot lysis and relief of symptoms. Thrombolytic therapy was effective in eight (73 percent) of 11 patients receiving urokinase and one (20 percent) of five patients receiving streptokinase. Of those with a central venous catheter, eight (73 percent) of 11 patients were successfully lysed, whereas only one (20 percent) of five patients was successfully lysed if no catheter was present. If thrombolytic therapy was performed less than or equal to five days of symptom onset, seven (88 percent) of eight patients were successful, if thrombolytic therapy was performed greater than five days after symptom onset, two (25 percent) of eight patients were successful. Symptoms were relieved and the catheter was preserved in patients in whom thrombolytic therapy was effective. Factors predicting success were as follows: (1) the use of urokinase compared with streptokinase; (2) the presence of a central venous catheter; and (3) a duration of symptoms less than or equal to five days.

Catheterization, Central Venous↗
PubMed1991

The swollen leg. Clinical significance and differential diagnosis.

An elderly patient with a swollen leg or legs can present a challenging problem in differential diagnosis. Although most swollen legs are the result of congestive heart failure, thrombophlebitis, cellulitis, or lymphedema, many other conditions should also be considered.

Age Factors↗
PubMed1990

Characterisation of the gene encoding a 104-kilodalton microneme-rhoptry protein of Theileria parva.

A neutralizing antiserum, C16, raised against sporozoites of Theileria parva parva was used to screen a lambda gt11 expression library of T. parva parva (Muguga) genomic DNA fragments. Proteins encoded by one phage clone, lambda TpS-17, were reactive with the C16 antiserum. Detailed characterisation of the DNA insert showed it to encode determinants found on four theilerial antigens of approximately 104, 90, 85 and 35 kDa. The sequence encoded by the clone is expressed during sporogony as a single RNA transcript of about 3000 nucleotides. On sequencing a portion of the 5000-bp insert, an open reading frame of 2772 bp was revealed that encoded a 104-kDa protein. Immunoscreening a library of subfragments of the DNA insert with the original antiserum localised sequences encoding the dominant antigenic determinants to an 800-bp stretch of DNA at the 3' end of the open reading frame. Sequence data from three subclones spanning this region show portions of the antigenic domains to be unusually rich in proline residues which are repeated every three amino acids. These repeats often take the form X-S(T)-P or X-K(R)-P. Antibodies directed against each of the three subclones recognize the 104- and 35-kDa antigens and different combinations of the 90- and 85-kDa kDa antigens, suggesting that the smaller proteins are derived from the 104-kDa antigen by limited proteolysis occurring at the carboxyl terminus end of the protein. In immunoelectron micrographs the antigen is associated with the microneme/rhoptry complexes of the sporozoite.

Amino Acid Sequence↗
PubMed1990

SfiI and NotI polymorphisms in Theileria stocks detected by pulsed field gel electrophoresis.

DNAs of Theileria parva parva, T. p. lawrencei, T. p. bovis and Theileria mutans stocks, from Kenya, Uganda, Zanzibar and Zimbabwe were digested with either SfiI or NotI and analysed using contour-clamped homogeneous electric field (CHEF) and field-inversion gel electrophoresis (FIGE). The SfiI-digested T. parva genomic DNA resolved into approximately 30 fragments while the NotI digestion produced between 4-7 bands. The summation of the sizes of SfiI fragments gave an estimate of 9-10 X 10(6) base pairs for the size of the T. parva genome. Heterogeneity within T. p. parva Muguga, Pemba/Mnarani and Mariakani stocks was detected. All the T. parva stocks analysed showed SfiI and NotI restriction fragment length polymorphisms (RFLP). Hybridisation of 5 SfiI-digested T. parva DNAs with a Plasmodium berghei telomeric repeat probe suggested that most of the polymorphisms and heterogeneity occurred in the telomeric or sub-telomeric regions of the genome. The recognition by the Plasmodium telomeric probe of 7-8 strongly hybridising SfiI bands indicates that the T. parva genome may possess at least 4 chromosomes. The T. mutans genome was cut frequently with the above enzymes resulting in large numbers of fragments predominantly below 50 kb, thus suggesting either a much higher G + C content than T. parva or the presence of highly reiterated G + C-rich regions.

Animals↗
PubMed1990

Ginger root--a new antiemetic. The effect of ginger root on postoperative nausea and vomiting after major gynaecological surgery.

The effectiveness of ginger (Zingiber officinale) as an antiemetic agent was compared with placebo and metoclopramide in 60 women who had major gynaecological surgery in a double-blind, randomised study. There were statistically significantly fewer recorded incidences of nausea in the group that received ginger root compared with placebo (p less than 0.05). The number of incidences of nausea in the groups that received either ginger root or metoclopramide were similar. The administration of antiemetic after operation was significantly greater in the placebo group compared to the other two groups (p less than 0.05).

Adolescent↗
PubMed1990

Stasis ulcer treatment with compression dressing.

A compression dressing system is an easily learned and effective alternative to the Unna boot for treatment of venous stasis ulcer. The treatment is well accepted by patients and appears to have efficacy comparable to that achieved with the boot, but without the problems associated with the boot, such as maceration, poor fit, and inability to observe and bathe the skin.

Humans↗