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J J Shields

Publications and source records attributed to J J Shields.

13 recordsLinked to original sources
PubMed1993

A highly polymorphic microsatellite in the class II Eb gene allows tracing of major histocompatibility complex evolution in mouse.

A hallmark of major histocompatibility complex (MHC) genes is their extraordinarily high level of polymorphism. Polymorphic residues on MHC molecules determine which peptide ligands they bind and present to effector T lymphocytes. Although the genetic mechanisms responsible for MHC polymorphism have been delineated, the timetable and the pathway of their diversification remain unclear. To trace MHC evolution, we have characterized a highly polymorphic microsatellite containing tandem repeats (TRs) of two tetranucleotide units, TGGA and GGCA, located at the 3' end of the second intron in the class II Eb gene of mouse. On the basis of length as well as sequence variations, 11 TR alleles were defined in 55 inbred mouse strains, which included MHC recombinant haplotypes and haplotypes derived from different subspecies of mouse. In this extensive sampling, a striking concordance was observed between the serologically identified class II proteins and the associated TR alleles. Examination of several strains carrying the same MHC haplotypes as well as strains carrying recombinant MHC haplotypes indicates that TR alleles are extremely stable. These observations suggest that TR polymorphism predates the separation of various subspecies of mouse. On the basis of sequence divergence, a genealogical tree has been constructed to depict evolution of the different TR alleles. Finally, evidence is presented that suggests this microsatellite polymorphism is generated by slipped-strand mispairing during DNA replication.

Alleles↗
PubMed1992

Characterization of two novel polymorphisms at the human parathyroid hormone gene locus.

Two new polymorphisms within the human parathyroid hormone (PTH) gene are described. One corresponds to a C----A transversion that destroys DraII and NlaIV restriction sites. The other is revealed by the enzyme XmnI, and its position has been mapped with respect to the PTH gene. We have also identified a sequence change that results in the TaqI restriction fragment length polymorphism (RFLP) described previously at this locus and have found that this sequence change also results in disruption of a BstBI site. Finally, we describe a polymerase chain reaction (PCR)-based method that permits a rapid evaluation of the DraII and BstBI (TaqI) polymorphisms. The introduction of these two additional RFLPs and this PCR-based assay should considerably extend the power of genetic analyses of the human PTH gene.

Base Sequence↗
PubMed1989

Factors associated with hospital workers' reactions to the treatment of persons with AIDS.

This article reports on how the increasing number of AIDS patients is having a significant impact on the delivery of healthcare services. Healthcare workers need to learn how to provide medical care for persons with AIDS as well as how to interact with and relate to them. Workers who have accurate information regarding the transmission of AIDS report more positive responses. In addition to didactic educational efforts hospital workers need explicit education on the psychosocial issues related to AIDS including such issues as fears of contagion, homosexuality, and death anxiety. Ethnic and cultural differences of both the AIDS population and healthcare workers must be addressed to relieve feelings of risk, stress, and discomfort. Each healthcare setting must determine the most effective means to educate all levels of staff on a continual basis.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Fine needle aspiration of para-aortic and pelvic lymph nodes showing lymphangiographic abnormalities.

Fifty-six fine needle aspirations of lymphangiographically abnormal pelvic and para-aortic lymph nodes were performed in 50 patients at The University of Michigan between January 1, 1977, and May 31, 1980. Fine needle aspiration was used both in the initial evaluation of patients with gynecologic malignancies and in the investigation of persistent and recurrent malignant disease. The overall diagnostic accuracy of fine needle aspiration was 74.0%. Fine needle aspiration yielded diagnostic cytologic specimens; it was safe and well tolerated, and in some instances it permitted the diagnosis of lymph node metastasis without laparotomy.

Biopsy, Needle↗
PubMed1982

Localization of the source of hyperinsulinism: percutaneous transhepatic portal and pancreatic vein catheterization with hormone assay.

Insulin concentrations were measured in the portal venous system through the percutaneous transhepatic approach in 12 patients with organic hyperinsulinism. Single insulinomas were found in 10, an adenoma and islet cell hyperplasia in one, and nesidioblastosis in one patient. Angiography localized adenomas in two. Local step-ups of insulin levels in the portal venous system, found in all patients with insulinomas, corresponded to tumor sites at surgery. Multiple step-ups were found in the portal venous system of the patient with nesidioblastosis and the patient with an adenoma with islet cell hyperplasia. Three tumors were localized in the head of the pancreas which would indicate the primary surgical approach rather than blind resection of the body and tail. Three of the 10 adenomas were not identifiable by palpation after pancreatic mobilization during surgery. In all patients, organic hyperinsulinism was cured after surgery. Percutaneous transhepatic portal and pancreatic vein catheterization with measurement of radioimmunoactive insulin concentrations is a safe and reliable method and may play an important role in the localization of adenomas in patients with normal angiographic studies and previous negative surgical explorations.

Adenoma↗
PubMed1982

Collateral channels and histopathology in hepatic vein occlusion.

Hepatic arteriography, venography, and histopathology were reviewed in 20 patients with hepatic venous occlusion. The hepatic histologic materials (14 patients) were carefully examined in retrospect and correlated with the angiographic findings. Hepatic arteriographic findings were usually nonspecific but revealed neoplasms in all six patients studied and collaterals in four. Collateral channels that were recognized angiographically in 15 patients were extrahepatic, intrahepatic-interlobar, and indeterminate. The intrahepatic type was found in the partial Budd-Chiari syndrome, whereas other patterns were present in both diffuse and localized forms of hepatic venous occlusive disease. Histologically, the centrilobular sinusoids were congested and distorted in association with parenchymal destruction and compression. Hepatic venography correlated poorly with histopathologic findings.

Adolescent↗
PubMed1981

Experimental renal infarcts: angiographic and histologic studies.

The renal arteries in three groups of four dogs were occluded to induce renal infarcts using Gelfoam, Gelfoam and steel coil, and barium suspension. Each agent was evaluated for its effect on renal renin output, arteriographic appearance, and the extent of renal infarct produced. Gelfoam embolization produced incomplete infarcts with hypertrophy of remaining viable tissue. Renal infarcts were more extensive with the combination of Gelfoam and coil than with Gelfoam alone. Barium embolization produced the most diffuse and extensive renal infarct. Renal vein plasma renin levels from the embolized kidney were significantly elevated in the Gelfoam-plus-coil dogs, but arterial pressures were significantly higher in only two of four of these dogs 10 weeks after embolization.

Angiography↗
PubMed1981

Discriminant arteriographic criteria in the management of forearm and hand ischemia.

Fifty-five patients (33 male and 22 female), 3 to 73 years in age, underwent aortic arch and selective upper extremity arteriography for the evaluation of forearm and hand ischemia from 1971 to 1980. Fifty-one patients had organic occlusive lesions (12 subclavian, 15 axillobrachial, 17 radial-ulnar, and 7 palmar-digital), including distal forearm and hand emboli, as a consequence of proximal occlusive disease in nine patients (5 subclavian, 2 axillobrachial, and 2 radial-ulnar). The remaining four patients had vasospastic disease. Major arteriographic findings of obstructive disease were defined by: morphology of lesions, symmetry or asymmetry of obstructions, segmental versus tandem lesion distribution, and the resultant pattern of collateral circulation. Vasodilatory pharmacoangiography with magnification technique frequently facilitated evaluation of digital and collateral vessels. Therapeutic interventions were dictated by clinical data heavily weighed by the arteriographic examination. Limited arteriographic studies would have been misleading in the evaluation of many patients.

Adolescent↗
PubMed1980

Pulmonary artery constriction by mediastinal lymphoma simulating pulmonary embolus.

Two cases of constriction of the pulmonary artery secondary to mediastinal lymphoma are reported. Both patients had clinical symptoms of pulmonary embolism. Radionuclide lung scans showed no perfusion of the right lung in one patient, and diminished perfusion of the right lung in the other. Pulmonary angiography revealed diffuse concentric narrowing of right main pulmonary arteries in both patients and of lobar branches in one, in whom severe encasement of the right pulmonary artery by a lymphomatous mass confirmed at autopsy. The decisive role of pulmonary angiography in determining the underlying pathology in patients with abnormal perfusion scans is illustrated.

Adult↗
PubMed1980

Biliary cystadenomas: sonographic-angiographic-pathologic correlations.

Three biliary cystadenomas are reported. Two occurred in the left lobe of the liver and the third involved the right lobe and the medial segment of the left lobe. All three patients had gray scale sonography of the liver and two underwent hepatic angiography. The sonographic features were similar to those of cystadenoma of the ovary or pancreas, that is, multilocular cystic lesions with septations and papillary projections. Angiographically the lesions were hypovascular with a faint rim of contrast-material accumulation in the wall and septa of the mass.

Adult↗