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Biomedical subjects

P F Jones

Publications and source records attributed to P F Jones.

At least 19 recordsLinked to original sources
PubMed1992

Mammalian neurotrophin-4: structure, chromosomal localization, tissue distribution, and receptor specificity.

Nerve growth factor, brain-derived neurotrophic factor, and neurotrophin-3 (NT-3) are the three members of the neurotrophin family known to exist in mammals. Recently, a fourth neurotrophin (designated neurotrophin-4 or NT-4), which shares all of the features found in the mammalian neurotrophins, has been identified in Xenopus and viper. We used sequences specific to the Xenopus/viper NT-4 to isolate a neurotrophin from both human and rat genomic DNA that appears to represent the mammalian counterpart of Xenopus/viper NT-4. Human NT-4 as well as a human NT-4 pseudogene colocalize to chromosome 19 band q13.3. Mammalian NT-4 has many unusual features compared to the previously identified neurotrophins and is less conserved evolutionarily than the other neurotrophins. However, mammalian NT-4 displays bioactivity and trk receptor specificity similar to that of Xenopus NT-4.

3T3 Cells↗
PubMed1991

Molecular cloning and identification of a serine/threonine protein kinase of the second-messenger subfamily.

A partial cDNA was isolated that encoded a protein kinase, termed rac (related to the A and C kinases). This cDNA was subsequently used to screen libraries derived from the human cell lines MCF-7 and WI38 and led to the isolation of full-length cDNA clones. DNA sequence analysis identified an open reading frame of 1440 base pairs encoding a protein of 480 amino acids (Mr, 55,716). This result was supported by the synthesis of a Mr 58,000 protein in an in vitro translation system that used RNA transcribed from cloned cDNAs with SP6 RNA polymerase. The predicted protein contains consensus sequences characteristic of a protein kinase catalytic domain and shows 73% and 68% similarity to protein kinase C and the cAMP-dependent protein kinase, respectively. Northern (RNA) analysis revealed a single mRNA transcript of 3.2 kilobases that varied up to 300-fold between different cell lines. Specific antisera directed towards the carboxyl terminal of the rac protein kinase were prepared and used to identify that phosphorylated several substrates in immunoprecipitates prepared with the rac-specific antisera.

Amino Acid Sequence↗
PubMed1991

Management of the impalpable testis: long-term results of the preperitoneal approach.

During a 12-year period 396 operations for undescended testes were carried out by one surgeon. In 90 boys the testis was impalpable, and exploration was performed using a muscle-splitting preperitoneal approach. Testicular volume and location were prospectively recorded at 3 months and 1 year, 94% were intrascrotal at 1 year and 84% were judged to have grown. At late follow-up 6 to 16 years (mean, 11 years) after ochidopexy, 81% of testes were in the scrotum and 57% were of normal volume. The value and advantages of this operative approach and its place in the management strategy of the impalpable testis are discussed.

Child↗
PubMed1991

Molecular cloning of a second form of rac protein kinase.

A novel serine/threonine protein kinase (termed rac-PK) has recently been identified and cloned from cDNA libraries derived from the human cell lines MCF-7 and WI38. A second form of this protein kinase, termed rac protein kinase beta, has been identified from cDNAs derived from the same cell lines. These two closely related forms show 90% homology, although the beta form with a predicted Mr 60,200 has a carboxyl terminal extension of 40 amino acids in comparison to the alpha form. This extension has a high serine content with 11 serine residues in the last 30 amino acids. The beta form of the protein has been shown by both in vitro translation and bacterial expression to be approximately 5000 Da larger than the alpha form. rac protein kinase beta is encoded by a 3.4-kb transcript and the alpha form is encoded by a 3.2-kb mRNA. Using gene-specific probes both transcripts were detected in all cell types analyzed, although levels of expression were different for the two forms. The catalytic domain of rac protein kinase beta shows a high degree of homology to both the protein kinase C and cyclic AMP-dependent protein kinase families, and hence rac protein kinases appear to represent a new subfamily of the second messenger serine/threonine protein kinases.

Amino Acid Sequence↗
PubMed1989

A new family of mouse homeo box-containing genes: molecular structure, chromosomal location, and developmental expression of Hox-7.1.

Two families of homeo box-containing genes have been identified in mammals to date, the Antennapedia- and engrailed-like homeo boxes, based on the sequence similarity to those from Drosophila. Here, we report the isolation of a homeo box-containing gene that belongs to a new family of which there are at least three related genes in the mouse genome. The homeo box of this new gene shows remarkable similarity to the Drosophila Msh homeo box that we designate as the prototype for this family. The gene maps to the proximal end of mouse chromosome 5 and does not cosegregate with any known homeo box-containing gene. We designate this locus Hox-7.1. In situ hybridizations to mouse embryos at different stages show a unique pattern of expression, as compared to other homeo box-containing genes described thus far. Hox-7.1 transcripts are detected in 9.5-day-old embryos in the neural crest, developing limb bud, and visceral arches. Later, this gene is expressed in regions of the face that are derived from neural crest and in the interdigital mesenchymal tissues in both the fore- and hindlimbs.

Amino Acid Sequence↗
PubMed1987

Splenectomy in the management of haematological disease.

Patients, both adults and children, with various haematological disorders who had splenectomy electively in the diagnosis, staging or treatment of their condition during a 15-year period in the Aberdeen hospitals were reviewed. The outcome regarding the disease and the immediate and long-term complications of splenectomy in this group of 185 patients are presented. Splenectomy has an acceptably low morbidity, even in patients with serious haematological disease, in the hands of an experienced surgical team, where there is close co-operation between surgeon and haematologist. Occasionally, late overwhelming infections may occur, despite prophylaxis with penicillin and pneumococcal vaccination. It seems likely that, in their zeal to report such hazards, authors may allow the pendulum against splenectomy to swing too far, in the direction of leaving patients, especially adults, with considerable symptoms and poor health, rather than risk the occasional consequences of the asplenic state.

Adolescent↗