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Biomedical subjects

K W Jones

Publications and source records attributed to K W Jones.

At least 91 records · Page 5Linked to original sources
PubMed1987

Testis development in a mouse with 10% of XY cells.

Two mouse Y-chromosome-related DNA probes were used to show that an aspermic sterile male mouse with small testes contained only approximately 10% of normal XY cells dispersed among normal XX cells. Examination of testis sections by in situ hybridization revealed that XY cells were nonrandomly concentrated in the testis tubules when compared with the interstitial cell population. These observations are discussed in the context of primary sex determination and histological differentiation of the testis.

Animals↗
PubMed1987

The use of Y-chromosome-specific repeated DNA sequences in the analysis of testis development in an XX/XY mouse.

A study, by means of Y-chromosome-specific repeated DNA probes, of mouse (ST) with small testes is reviewed. Mouse ST was shown to be a somatic mosaic of 10% XY and 90% XX cells. The cellular composition of the azoospermic testis reflected the overall proportions of XX and XY cells but it was found that XY cells predominated in the Sertoli cells of the testis tubules. These findings have been interpreted to indicate a fundamental role for the Sertoli cell in inducing testis organization in the indifferent gonadal rudiment, involving the expression of the Y chromosome.

Animals↗
PubMed1987

Somatic DNA variability in human breast carcinoma.

Bkm-related probe 2[8], consisting mainly of GATA repeats, detects a hypervariable pattern of restriction fragment length polymorphisms in human DNA which is normally developmentally stable. However, specific somatic DNA variability was found in 53% (7/13) of human breast carcinomas, but not in eight cases of bladder carcinoma, when compared with leukocyte DNAs from the same patient under the same conditions. Certain of the restriction fragments detected carry both GATA-related sequences and sequences related to the M13 vector. Comparison of BstN1 digests of tumour and cognate leukocyte DNA revealed a further variable ethidium-stained restriction fragment class, not recognised by the probe, in 93% of breast and in 63% of bladder carcinomas.

Breast Neoplasms↗
PubMed1987

Survival following cardiac transplantation--what are acceptable standards?

In an 18-month period, 50 orthotopic cardiac transplantations were done in Utah in 48 patients with end-stage heart failure. The 12-month actuarial survival was 98%, indicating that successful cardiac transplantation can be done in a newly established program and that the intermountain West has an adequate supply of potential recipients and donors for a moderate- to high-volume program. Furthermore, the administration of cardiac transplantation in a setting of other treatment modalities of heart failure in a multi-institutional program that crosses private practice-academic barriers is feasible. Results such as these need to be considered by the federal government as it establishes eligibility criteria for centers to be approved for Medicare-funded cardiac transplantation.

Actuarial Analysis↗
PubMed1986

Bkm sequences are polymorphic in humans and are clustered in pericentric regions of various acrocentric chromosomes including the Y.

Probes of uncloned Bkm satellite DNA and a Drosophila clone 2 (8), consisting mainly of GATA repeats related to a major sequence component in Bkm, have been used to probe Southern blots of human male and female DNAs obtained from a Caucasian and an Australian aboriginal population and to human chromosomes in situ. Hybridization was observed to a distinct and an indistinct series of bands against a smeared background. The same distinct bands are identified in the DNA samples with both probes, but are most readily detected using the uncloned Bkm probe. Most restriction bands are common to both populations and some are polymorphic. However, certain bands appear to be characteristic of the Australian aboriginal samples. There are no distinct sex-linked patterns. However all of the small acrocentric human chromosomes, including the Y chromosome show hybridization to uncloned Bkm in situ.

Centromere↗
PubMed1986

Regional distribution of lead in the brains of lead-intoxicated adult mice.

The susceptibility of adult neural tissues to the detrimental effects of Pb poisoning has prompted the present distributional analysis of lead in the brains of chronically lead-exposed mice. A high-resolution microPIXE method was developed for measuring Pb in whole-brain cryosections derived from chronically lead-exposed mice. Spatial resolutions as small as 20 micron were obtained. Details of the methodology are presented together with procedures for Pb standard preparation and control measures employed to reduce potential errors of Pb assay associated with taking brain sections with steel alloy knives. The unique advantages of making microPIXE Pb determinations in nonpreselected brain anatomic regions using freeze-dried semithick cryosections are reviewed. The study revealed that, in lead-intoxicated mice, there existed wide regional variation in Pb concentration in the ppm range, in 50 micron sagittal or coronal sections. Higher Pb levels were found in discrete brain regions of lead-treated adult mice than in matched control brains. Suggestions for further studies of Pb kinetics using microPIXE methods in adults and immature animals, including components of neural barrier tissues, are reviewed.

Animals↗
PubMed1985

Elective conversion from cyclosporine to azathioprine in recipients with stable renal function 6 months after kidney transplantation.

The average cost of cyclosporine over the first 6 months after renal transplantation has been $2450/recipient for recipients with stable renal function. Fifty-nine percent of all patients transplanted in 1984 do not have a third-party payment mechanism for outpatient medicines and many cannot afford cyclosporine. The expense of cyclosporine has, thus, mandated developing a protocol for conversion from cyclosporine to azathioprine. Using a protocol, which included a short overlap of cyclosporine and azathioprine and a temporary, modest increase in prednisone dose, 27 renal allograft recipients with stable renal function have undergone conversion of their immunosuppressive regimen approximately 6 months posttransplant with a minimum follow-up of 4 months from conversion. There has been no graft loss or patient death. Mean serum creatinine has been reduced in recipients with stable function after conversion (1.4 mg/dl 3 months postconversion compared to 1.8 mg/dl preconversion). However, acute breakthrough rejection has occurred in four recipients (15%), and, after reversal of rejection, mean serum creatinine is elevated (3.1 mg/dl) in this group. Only a single patient developed an infection during the conversion period. Thus, a policy of conversion from azathioprine appears to be a reasonable compromise for those patients who cannot afford long-term outpatient treatment with cyclosporine.

Adolescent↗
PubMed1985

Comparison of the incidence of bladder hyperreflexia in patients with benign prostatic hypertrophy and age-matched female controls.

Detrusor hyperreflexia long has been recognized as a condition associated with certain neurological disorders (that is multiple sclerosis, cerebrovascular accidents, spinal cord injuries and parkinsonism). Bladder outlet obstruction (primarily benign prostatic hypertrophy) recently has been added to the list. Hyperreflexia associated with bladder outlet obstruction does not always resolve with relief of the obstruction. Our study of age-matched female controls indicates that there is a baseline rate of hyperreflexia associated with the aging process alone. This baseline hyperreflexia probably explains persistent symptoms in men with hyperreflexia following relief of the obstruction.

Aged↗
PubMed1984

The conserved nucleotide sequences of Bkm, which define Sxr in the mouse, are transcribed.

We have recovered a conserved transcribed component of the snake W chromosome satellite DNA (Bkm) from Drosophila and male mouse libraries. This consists of repeats of the tetranucleotide GATA that are concentrated in the sex-determining region of the Y chromosome of mouse, on the W chromosome of snakes, and in the proximal region of the X chromosome of D. melanogaster, and it appears to be transcribed in a sex-specific and developmentally regulated manner. Sequencing studies show that, unlike most other transcribed repeats, the GATA repeats potentially contain open reading frames. These encode mainly the amino acids leucine, serine, isoleucine, and tyrosine but with occasional variant codons that differ in different clonal isolates. Transcription is exclusive to the GATA strand in different tissues of the same organism and in different unrelated organisms. The complementary strand CTAT contains stop codons in all reading frames. The possible developmental significance of these sequences is discussed.

Amino Acids↗
PubMed1983

Bacterial adherence to bladder tumors in the mouse.

Mice with intravesical urothelial tumors (MBT-2) were challenged with E coli inoculated intravesically. Adherence of bacteria measured at 15 min or persistent infection at 24 h was significantly greater in the tumor-bearing bladders than in normal non-tumor-bearing mice. The tumor-bearing portion of the bladder contained significantly more bacteria than the non-tumor-bearing portion.

Adhesiveness↗
PubMed1983

Evolutionary conservation of sex specific DNA sequences.

A family of DNA sequences which appears to be limited to eukaryotes is concentrated on the sex-determining chromosomes of species as widely separated evolutionarily as snakes and mammals. The significance of this distribution is presently seen in terms of the function of these sequences in cycles of chromosome condensation and decondensation involved in the control of gene expression. Thus, their concentration on the sex chromosomes is interpreted in the context of the evolution of such chromosomes which, it is hypothesised, involves the superimposition of the controls of the dominant sex-determining gene(s) upon the entire linkage group. This would result in the prevention of the large majority of its genes from having effects upon the phenotype and, in consequence, lead to their mutation to functionlessness at the maximum rate.

Animals↗
PubMed1982

Adenovirus-related RNA sequences in human neurogenic tumours.

Thirty two human tumours, mainly neurogenic, have been investigated for the presence of adenovirus-related RNA sequences. 3H-labelled tumour virus DNA probes derived from human adenoviruses types 2 and 12, bovine adenovirus type 3, and avian adenovirus CELO were hybridized in-situ on tumour kryostat sections under conditions that detect complementary RNA. Tumour virus-related RNA was detected in 62% of all tumours tested, but was not detectable in normal human brain tissues. Expression of tumour virus-related RNA was found in 2/4 astrocytomas, 2/4 metastatic brain carcinomas, 2/2 glioblastomas, 1/1 melanoma, 5/7 meningiomas, 4/4 neurinomas, 1/2 oligodendrogliomas, and 1/1 rhabdomyosarcoma. The presence of adenovirus-related RNA in the majority of human neurogenic tumours may reflect a viral involvement in the pathogenesis of these tumours.

Adenoviridae↗
PubMed1982

Papovavirus-related RNA sequences in human neurogenic tumours.

Thirty-two human brain tumours were investigated for the presence of papovavirus-related RNA sequences. Radiolabelled viral DNAs isolated from SV40, BKV, HDV, and BPV were hybridized in-situ on to tumour kryostat sections under conditions that detect complementary RNA. SV40-related RNA was detectable in 34% of all tumours tested but was not found in normal human brain tissue. SV40-positive tumours included 1/1 angiofibroma, 1/4 astrocytomas, 2/4 metastatic brain tumours, 1/1 melanoma, 3/7 meningiomas, 2/4 neurinomas, 1/2 oligodendrogliomas. Bovine papilloma virus-, BKV-, and HDV-related RNAs were absent from all tissues tested. The presence of SV40-related nucleic acids in a large number of human neurogenic tumours may reflect a viral involvement in the etiology of these tumours.

Astrocytoma↗