Search PubMed⌕ Search

Biomedical subjects

J C Weber

Publications and source records attributed to J C Weber.

At least 19 recordsLinked to original sources
PubMed1992

[Rheumatoid factors].

Rheumatoid factors (RF), which are auto-antibodies recognising the Fc fragment of IgGs, are the commonest auto-antibodies in man. They are present in polyclonal form in a large number of auto-immune disorders as well as in certain inflammatory states. In monoclonal form, they are frequently the product of "mature" malignant (chiefly Waldenström's macroglobulinemia and chronic lymphoid leukemia) and allegedly benign (such as cryoglobulinemias) lymphoid proliferations. In addition, RF account for a significant part of the normal antibody repertory, notably during the fetal and neonatal periods, suggesting that they may play an important role in the development and regulation of the immune system. As a result, RF are an excellent model for the analysis of auto-immunity in man. Thus many indirect (analysis of antigens recognised and of idiotopes carried) and, more recently, direct (protein or nucleotide sequencing of their various regions) studies have now provided the following conclusions. RF are coded by a very limited repertory of V genes. These genes are present in the normal genome and appear to be highly preserved in the human species. They are used with very few somatic mutations by monoclonal B proliferations (which opens up valuable therapeutic possibilities) as well as probably by RF producing B lymphocytes in normal individuals. In contrast, in the context of auto-immune disorders, these same genes have many somatic mutations suggesting maturation governed by the antigen and/or escape from idiotype control.

Autoimmune Diseases↗
PubMed1991

Cunninghamella bertholletiae: an uncommon agent of opportunistic fungal infection. Case report and review.

Cunninghamella bertholletiae is a fungus of the Zygomycetes class, Mucorales order. Only very few cases of disseminated infection have been reported. We observed a new case in a 19 years old man with severe aplastic anemia, due to pulmonary primoinfection and hematologic dissemination. This aplastic anemia failed to respond first to an antithymocyte globulin and steroid treatment and then to cyclosporine A. Deferoxamine was infused weekly to prevent iron overload. During a second antithymocyte globulin and steroid treatment, the patient developed bilateral pneumonia. Culture of the broncho-alveolar washing fluid established the diagnosis by isolation of C. bertholletiae. Despite amphotericin B and 5-fluorocytosine intravenous therapy, the patient died of disseminated infection six days after diagnosis, which was confirmed by necropsy. Underlying conditions, diagnosis and treatment are discussed, together with a review of the literature.

Adult↗
PubMed1990

Recognition of synthetic peptides of Sm-D autoantigen by lupus sera.

The reactivity of autoantibodies present in the serum of patients with systemic lupus erythematosus (SLE) was investigated by ELISA using seven overlapping synthetic peptides representing the entire sequence of the polypeptide D component of 'Sm antigen'. Of the 165 SLE sera tested, 59% were found to contain IgG antibodies able to bind to peptide 1-20, while 37% of the sera reacted with peptide 44-67. All sera reacting with peptide 44-67 also reacted with peptide 1-20. These two peptides were only seldom recognized by the sera of 187 patients with other rheumatic autoimmune diseases or by 53 sera of normal individuals. In a parallel study using sera that reacted with the D band in immunoblotting, most of the sera recognized peptides 44-67 (89%) and 1-20 (67%), while 33% of them reacted with peptide 97-119. The use of these synthetic peptides in ELISA may be of considerable help for detecting anti Sm autoantibodies.

Amino Acid Sequence↗
PubMed1989

X-ray crystallographic analysis of the structural distortions induced by substitution and annulation of the dodecahedrane nucleus.

Methyl dodecahedranecarboxylate, C22H22-O2, (4), Mr = 318.42, monoclinic, C2/c, a = 12.600 (2), b = 7.992 (4), c = 28.975 (7) A, beta = 101.79 (2) degrees, V = 2856 A3, Z = 8, Dx = 1.48 g cm-3, lambda(Mo K-alpha) = 0.71073 A, mu = 0.84 cm-1, F(000) = 1360, T = 294 K, R = 0.044 for 2109 unique reflections with Fo2 greater than 3 sigma(Fo2). 21-Phenylcyclopropadodecahedrane, C27H24, (5), Mr = 348.49, tetragonal, P4(2)/n, a = 17.528 (3), c = 10.752 (2) A, V = 3303 A3, Z = 8, Dx = 1.40 g cm-3, lambda(Mo K-alpha) = 0.71069 A, mu = 0.85 cm-1, F(000) = 1488, T = 295 K, R = 0.053 for the 1773 unique reflections with Fo2 greater than 1 sigma(Fo2). The molecular geometries of methoxycarbonyldodecahedrane (4) and 21-phenylcyclopropadodecahedrane (5) are compared to those of the parent C20H20 hydrocarbon (1) and its 1,16-dimethyl derivative (2). For both (2) and (4), the framework is modestly distorted by the substituents, the intracavity distance being more extended along the axis that contains the pendant group(s). Remarkably for (5), its cyclopropane ring has all C-C bonds and internal angles essentially equal, and those dodecahedrane bonds in the immediate vicinity of the ring fusion are extensively perturbed.

Molecular Structure↗
PubMed1988

Oral carriage of Candida albicans, ABO blood group and secretor status in healthy subjects.

ABO blood group and secretor status were determined in healthy subjects in relation to oral carriage of Candida albicans, using a mouthwash technique to identify carriers and non-carriers. Of 100 subjects studied, 32% carried Candida, the main species isolated being C. albicans (94% isolates). Carriage of C. albicans was significantly associated with blood group O (p less than 0.001) and independently, with non-secretion of blood group antigens (p less than 0.001), with the trend towards carriage being greatest in group O non-secretors. This suggests that in healthy subjects, blood group O and non-secretion of blood group antigens are separate and cumulative risk factors for oral carriage of C. albicans.

ABO Blood-Group System↗
PubMed1987

Can embolic stroke be diagnosed on the basis of neurologic clinical criteria?

Diagnosis of embolic stroke is based on identification of a source of embolus (SOE) and on neurologic symptoms acknowledged as "clinical criteria." To test the validity of these criteria, we analyzed the symptoms at onset in 193 patients hospitalized after acute cerebral infarction. Patients were grouped according to identification of a cardiac SOE (106 patients), an arterial SOE (38 patients), or no SOE (49 patients). Cross-tabulations demonstrated that only rapidity and loss of consciousness at onset were associated with the presence of a cardiac SOE to a significant degree. Although these symptoms were highly specific for cardiac SOE, they were not sensitive. A distinct clinical neurologic profile from the symptoms and mode of onset was not identified.

Adult↗
PubMed1985

Visual function and academic performance.

Evaluation of 1,910 first-, second-, and third-grade students indicated that visual function and academic performance as measured by reading were not positively related. Visual function tests included visual acuity, muscle balance, preferred eye and hand, color vision, refraction, sensory and motor function, and a writing and drawing task. Academic tests included the Metropolitan Readiness Test, the Cognitive Abilities Test, the Iowa Test of Basic Skills, and the teacher's assessment of reading level. A simple test which can be completed during the office visit and interpreted by the ophthalmologist in the office included drawing, copying, and writing. A segment of this test, the "draw a bicycle test," can be used by an ophthalmologist to demonstrate the difference between vision and performance when examining a child up to third-grade level who is referred because of school failure.

Accommodation, Ocular↗