PubMed Health⌕ Search

Biomedical subjects

J B Graham

Publications and source records attributed to J B Graham.

At least 19 recordsLinked to original sources
PubMed1992

The effects of ultrasound-guided shock waves during early pregnancy in Sprague-Dawley rats.

Pregnancy is a contraindication to extracorporeal shock wave lithotripsy (ESWL) because of its possible harm to the embryo or fetus caused by shock waves or ionizing radiation. In this study timed-pregnant rats were subjected to shock waves early in gestation using a lithotriptor having ultrasound imaging. In a pilot group undergoing immediate laparotomy, it was determined to what extent the pelvic structures were effected. Then a test group was exposed to shock waves and carried to near term pregnancy along with an identical group of pregnant, sham procedure rats. A laparotomy all were inspected for fetal viability, fetal abnormalities, and maternal organ damage. Fetuses located nearest the focal area of maximum shock wave energy showed lower mean weight than controls. There was no recognizable gross or microscopic fetal damage.

Animals↗
PubMed1992

Digital image analysis of shark gills: modeling of oxygen transfer in the domain of time.

Digital radiographic imaging of blood circulation through leopard shark gills establishes a secondary lamellar transit time of 6.5 s. This duration, combined with estimates of cardiac output and hemoglobin-oxygen affinity, permits novel modeling of gill oxygen transfer in the time domain. The temporal model allows assessment of factors contributing to previously noted discrepancies between physiological and morphometric branchial oxygen conductance estimates. Lamellar transit time for shark blood is 20 times greater than human alveolar transit time, and thus correlates with a slower rate of hemoglobin-oxygen binding and a greater diffusion distance.

Animals↗
PubMed1991

Population genetics of the Malmö polymorphism of coagulation factor IX.

The distribution of 1,198 Malmö alleles was examined in 822 men from 16 indigenous populations and 188 women from 7 of the ethnic groups. Subjects were from several European countries, the Mediterranean, East Asia, and the USA (Anglo- and African-Americans). The frequencies of the rarer (Malmö B) allele were approximately equal across Europe, the highest frequencies (0.36) being in the French and Anglo-Americans; no population was observed with clearly the highest frequency. They diminished slightly at moderate distances from Europe (Tunisia, Ethiopia) and greatly at longer distances (East Asia and West Africa). In Orientals, the frequencies ranged from 0.07 (East Indians) to 0.03 (the Chinese) and from 0.0 to 0.15 in African-Americans. Assuming selective neutrality, the data are consistent with the European origin of the 'B' allele when the population was small and outward spread.

Africa, Northern↗
PubMed1991

The varying frequencies of five DNA polymorphisms of X-linked coagulant factor IX in eight ethnic groups.

Five RFLPS of X-linked coagulation factor IX were evaluated in more than 500 normal persons (723-804 X chromosomes) of both sexes who belonged to eight ethnic groups: Anglo-Americans, Basques, Swedes, African-Americans, East Africans, East Indians, Chinese, and Malays. The polymorphisms, 5' to 3', were BamHI, XmnI, TaqI, MnlI, and HhaI. A PCR procedure was developed for three previously described RFLPs-XmnI, TaqI, and MnlI; a PCRP procedure was developed for BamHI, and a PCRP which had been described by others was used for HhaI. Europeans were the most polymorphic, African-Americans and East Africans were intermediate, and Orientals were the least polymorphic. Extragenic 3' HhaI was highly polymorphic in most groups, and extragenic 5' BamHI was polymorphic only in persons with African ancestry. Two major haplotypes predominated among 247 men, and the expected and observed heterozygosities were concordant among women. Allelic association was very strong between the three intragenic PCRPs; it was present but weak between 5' extragenic BamHI and XmnI. No association was found between 3' extragenic HhaI and MnlI.

Asian People↗
PubMed1990

The utility of a HindIII polymorphism of factor VIII examined by rapid DNA analysis.

A previously described HindIII restriction fragment length polymorphism (RFLP) of factor VIII (FVIII) has its polymorphic site in the unsequenced nineteenth intron. We have located the polymorphic site, as well as an invariant site, by amplifying and sequencing IVS 19 using the polymerase chain reaction (PCR). The oligonucleotide primers were synthesized from known FVIII sequence on either side of the 19-20 splice junction. The amplified product was cloned into a plasmid and sequenced by the dideoxy chain termination method. The polymorphic HindIII site was 103 bp and the invariant site 184 bp from the 3' end of the nineteenth exon. The frequency of the polymorphism was determined in 457 subjects (643 chromosomes) of seven ethnic groups on whom frequency of the BclI RFLP of IVS 18 was also assessed. The HindIII site is highly polymorphic in all groups, approximately 0.25:0.75, the expected heterozygosity averaging 37.6%, and the observed number of heterozygotes did not differ significantly from expectation. The (+):(-) allelic ratio is similar in all groups, except African-Americans in whom it is reversed. Strong allelic association (linkage disequilibrium) is present between the HindIII polymorphism of IVS 19 and the BclI polymorphism of IVS 18.

Alleles↗
PubMed1979

The separation of Willebrand factor from factor VIII-related antigen.

The three activities associated with factor VIII--coagulant (VIII:C), antigenic (VIIIR:Ag), and platelet agglutinating or Willebrand factor (VIIIR:WF)--have been separated by sequential antibody affinity chromatography, utilizing a rabbit antibody to factor VIII and a spontaneous human antibody to VIII:C. Normal plasma differentially lost its factor VIII-related antigen following passage over the rabbit antibody column. Subsequent passage of the VIIIR:Ag-depleted plasma over the human antibody column resulted in the loss of VIII:C activity, with retention of the Willebrand factor activity, antigen being partially recovered from the heterologous antibody column. These experiments demonstrate that it is possible to separate two of the factor VIII activities, VIIIR:Ag and VIIIR:WF, which are usually regarded as properties of a single molecule.

Antibody Affinity↗
PubMed1979

Genetics of classic von Willebrand's disease. II. Optimal assignment of the heterozygous genotype (diagnosis) by discriminant analysis.

In classic von Willebrand's disease (vWd), assignment of the heterozygous genotype for genetic studies and diagnosis for clinical purposes (which are not exactly the same) are formidable problems. We have pointed out in the first report in this series that almost 50% of the members of two large kindred who transmitted this disease, and were therefore heterozygous, were scored as normal by the usual tests of hemostasis. This report describes how this large proportion can be significantly reduced by application of discriminant analysis. Using linear discriminants in three variables--coagulation factor VIII (VIII:C), factor-VII-related antigen (VIIIR:Ag), and the ristocetin cofactor related to factor VIII (VIIIR:WF)--we were able to classify as heterozygous more than 80% of the transmitters in the two large kindred. It was of particular interest that the four parents of two related vWd homozygotes could be scored as heterozygous by discriminant analysis even though all their laboratory tests were within the normal ranges.

Adult↗