Search PubMed⌕ Search

Biomedical subjects

J R Rice

Publications and source records attributed to J R Rice.

54 records · Page 3Linked to original sources
PubMed1983

Anticentromere antibody. Clinical Correlations and association with favorable prognosis in patients with scleroderma variants.

The presence of antibody to the chromosomal centromere appears to be associated with a subset of patients with the limited CREST form of scleroderma. To further define the prognostic value of this autoantibody, 27 patients, who were identified as having anticentromere antibody by screening antinuclear antibody tests using HEp-2 cell substrates, were followed clinically and serologically for 2 years. The presence of anticentromere antibody is common in the limited CREST forms of systemic sclerosis, and it is often the only autoantibody specificity present in the sera of patients with the CREST variant. When compared with other patients who exhibit speckled or nucleolar antinuclear antibody patterns, those with anticentromere antibody had significantly less major organ system involvement.

Adult↗
PubMed1983

Occult fractures of the knee: tomographic evaluation.

Seven adults with painful effusions of the knee were examined for occult fractures using pluridirectional tomography in the coronal and lateral planes. Six patients (ages 50-82 years) were osteopenic and gave histories ranging from none to mild trauma; one 26-year-old man was not osteopenic and had severe trauma. In all cases, routine radiographs were interpreted as negative, but tomography demonstrated a fracture. Five fractures were subchondral. Bone scans in 2 patients were positive. The authors conclude that osteopenic patients with a painful effusion of the knee should be considered to have an occult fracture. While bone scans may be helpful, tomography is recommended as the procedure of choice to define the location and extent of the fracture.

Aged↗
PubMed1983

Prostaglandin H synthase-catalyzed activation of benzidine: a model to assess pharmacologic intervention of the initiation of chemical carcinogenesis.

Carcinogens which cause cancers in tissues distal to their entry are thought to require metabolic activation before covalent binding to macromolecules. The hydroperoxidase component of prostaglandin H synthase (PHS) activates certain carcinogens and a model describing this process is presented. The procarcinogen benzidine was used to identify sites at which microsomal PHS-catalyzed binding might be inhibited by pharmacologic agents. Activation of benzidine was determined by assessing free radical cation formation and covalent binding to protein. Reduction of benzidine diimine to diamine was also assessed. This study provides the first demonstration of inhibition of PHS-activated benzidine binding by propylthiouracil, methimazole, MK447, vitamin C and phenidone. The agents tested identified the following sites at which PHS-catalyzed binding of benzidine can be prevented: 1) inhibition of generation of the peroxide cosubstrate for benzidine oxidation; 2) inhibition of prostaglandin hydroperoxidase; 3) reduction of oxidized intermediate(s) to the parent compound; and 4) conjugation of the activated intermediate(s). This study provides a basis for further investigations of the pharmacologic intervention of chemical carcinogenesis.

Animals↗
PubMed1982

Lymphocytic lymphoma and systemic lupus erythematosus: their coexistence with antibody to the Sm antigen.

The serologic and clinical features of a 32-year-old women with coexistent systemic lupus erythematosus and lymphoma were studied. A cervical node biopsy specimen demonstrated nodular, poorly differentiated lymphocytic lymphoma; subsequent development of polyarthralgias prompted evaluation for connective-tissue disease, and a high titer of antinuclear antibody was found. Immunochemical studies proved that this antibody was directed to the Sm antigen, a serologic finding highly specific for systemic lupus erythematosus. This antibody has been maintained throughout the course of the patient's disease, characterized by persistent lymphadenopathy, pleuropericarditis, arthritis, hypocomplementemia, hyperglobulinemia, and a slight elevation of titers of anti-DNA antibody. The course of the lymphoproliferative disorder has been consistent with that of an indolent non-Hodgkin's lymphoma. In sera from other patients with lymphoproliferative disorders, anti-Sm antibody was not found. These findings emphasize the importance of establishing the antigenic specificity of antinuclear antibodies detected in the sera of patients with neoplasia.

Adult↗
PubMed1978

High accuracy finite difference approximation to solutions of elliptic partial differential equations.

A flexible finite difference method is described that gives approximate solutions of linear elliptic partial differential equations, Lu = G, subject to general linear boundary conditions. The method gives high-order accuracy. The values of the unknown approximation function U are determined at mesh points by solving a system of finite difference equations L(h)U = I(h)G. L(h)U is a linear combination of values of U at points of a standard stencil (9-point for two-dimensional problems, 27-point for three-dimensional) and I(h)G is a linear combination of values of the given function G at mesh points as well as at other points. A local calculation is carried out to determine the coefficients of the operators L(h) and I(h) so that the approximation is exact on a specific linear space of functions. Having the coefficients of each difference equation, one solves the resulting system by standard techniques to obtain U at all interior mesh points. Special cases generalize the well-known 0(h(6)) approximation of smooth solutions of the Poisson equation to 0(h(6)) approximation for the variable coefficient equation -div(p grad[u]) + Fu = G. The method can be applied to other than elliptic problems.

Journal Article↗
PubMed1978

Cryoablation of drug-resistant ventricular tachycardia in a patient with a variant of scleroderma.

A 37-year-old man with a benign variant of scleroderma (CRST syndrome: calcinosis circumscripta, Raynaud's phenomenon, sclerodactyly, and telangiectasia) presented with recurrent ventricular tachycardia. Preoperative electrophysiologic study suggested that the mechanism of tachycardia was an ectopic pacemaker focus in the right ventricle. Right ventricular dilatation, tricuspid insufficiency, normal pulmonary pressures, and normal coronary arteries were also demonstrated. At surgery, epicardial mapping localized the site of origin of ventricular tachycardia to the anterior right ventricle near the crista supraventricular. Intramural recordings of the site of tachycardia demonstrated autonomous activity unreflected on the peripheral ECG during brief periods of sinus rhythm. Local epicardial cooling of this area with a cryoprobe promptly terminated ventricular tachycardia with resumption of tachycardia on warming. The focus was ablated by freezing the area at -60 degrees C. The patient remained free of dysrhythmia on no anti-arrhythmic agents for eight months at which time he had a single recurrence of ventricular tachycardia from a different site in the right ventricle. This technique offers a method for ablating sites of dysrhythmia arising in diffusely diseased myocardium.

Adult↗
PubMed1976

Preneoplastic lesions in the human breast.

A subgross sampling technique with histological confirmation was used to study the pathology of 119 whole human breasts, either cancer-associated (that is, containing cancer or contralateral to a cancer) or taken from random routine autopsies. Atypical lobules were observed much more frequently in the cancer-associated group than in the group of routine autopsy breasts. Atypical lobules showed varying degrees of anaplasia that formed a continuum between normal epithelium and carcinoma in situ, usually of the common ductal type. As apprarent markers for increased cancer risk, atypical lobules in the human breast may be homologous to hyperplastic alveolar nodules that are abundant in high mammary cancer strains of mice. This indirect evidence supports the hypothesis that atypical lesions are common preneoplastic lesions in the human mammary gland.

Breast Neoplasms↗
PubMedDate not supplied

Solitary osteochondroma of the foot: an in-depth study with case reports.

Osteochondroma represents the most common benign bone tumor and occurs most frequently in the proximal humerus, tibia, and distal femur. The bones of the foot, by comparison, are less commonly involved. The tumor appears to be a developmental defect of bone preformed in cartilage rather than a true neoplasm. However, on rare occasions it may undergo chondrosarcomatous degeneration, thus demonstrating neoplastic behavior. A review of the literature, including clinical features of osteochondroma, radiologic and histologic characteristics, and theories on pathogenesis, is presented. Information concerning principles of surgical treatment, techniques of diagnosis, and facts to aid in the differential diagnosis of osteochondroma is presented also. Finally, a series of case reports is presented to demonstrate the surgical treatment of osteochondroma of the foot. Included are three cases of phalangeal osteochondroma, one of metatarsal osteochondroma, and an unusual report of osteochondroma of the talus. A case report and discussion of a patient with juxtacortical circumscripta myositis ossificans of the foot is also presented to demonstrate how information on lesions included in the differential of osteochondroma can be utilized clinically to make the diagnosis.

Adult↗
PubMedDate not supplied

Independent expression of autoantibodies in systemic lupus erythematosus.

Antibodies to components of the cell nucleus have been viewed as specific serological markers of systemic lupus erythematosus (SLE). To determine whether these autoantibodies exhibit common regulation of their expression, antibody levels have been quantitatively assessed in serial samples from patients producing at least 2 different antibody specificities. In a comparison of the peak antibody levels as a measure of immune responsiveness, the magnitude of the antiDNA response varied independently of either the antiSm or the antiRNP responses. Serial analysis with selected patients demonstrated that antiDNA levels fluctuated according to a pattern related to disease activity. In the same patients, however, antiSm and antiRNP antibodies showed little variation in level, with no consistent relationship to disease activity. Furthermore, following therapy, antiDNA levels fell while neither antiSm nor antiRNP levels showed significant alteration. These results suggest that in SLE, autoantibodies may arise from distinct immunoregulatory disturbances, each characterized by a unique relationship to disease activity and response to therapy.

Antibodies, Antinuclear↗
PubMedDate not supplied

Characterization and comparison of commercially available antinuclear antibody kits using single pattern index sera.

The wide variety of commercial kits used to test antinuclear antibodies (ANA) by indirect immunofluorescence (IIF) makes comparison of data from different laboratories difficult. Data comparing the sensitivity and feasibility of the various kits are not available. Eight different methods using tissue section and monolayer substrates for evaluating serum ANA by IIF were compared using single pattern ANA-positive sera. A rationale for selection among these kits and guidelines for interlaboratory comparison is presented.

Amnion↗