The freeze-fracture technique was used to study the fine structure of native collagen from rat tendon and lung. The collagen filaments were organized into a spiraled lamellar substructure within each fibril. Small particles, representing the broken ends of the collagen filaments, were found in nearly straight rows when the lamellae were broken tranversely. Filamentous connections were shown which span the interfibrillar matrix and unite all of the fibrils into a reticular network. The fibrils were coated with material that was greatly hydrated in vivo. Sublimation occurred more rapidly from some portions of the coating substance than from others, resulting in a banding pattern with a 610 A repeat distance.

Animals↗

PubMedDate not supplied

Heterogeneity of Alzheimer's disease. An interpretive review.

Explore the source record for details and available documents.

Aged↗

PubMedDate not supplied

HLA antigens in different age groups.

HLA typing was performed for 17 antigens on cells from 189 unrelated, normal white Caucasians. No significant differences (p greater than 0.05) in distributions of different markers were found among the age groups. There does not seem to be a relation between heterozygosity at HLA-A and HLA-B loci and survival until old age.

Adult↗

PubMedDate not supplied

Serum parathyroid hormone levels and serum calcium levels from birth to senescence.

1. Calcium and immunoreactive parathyroid hormone (iPTH) levels were measured in sera of 1334 normal subjects ranging from newborn to over 80 years of age. Albumin was measured in samples from the population of adults, which was 80% white, 15% black and 5% oriental. 2. Serum calcium and iPTH levels in children tended to be higher in the first three years of age; no sex differences were noted. Values for serum calcium and iPTH were higher in children than in adults. 3. Serum calcium, iPTH and albumin showed more variation in groups of white, black and oriental women than in similar groups of men. In white females the mean serum calcium remained fairly constant until age 60, whereas in black women it rose steadily from age 20-29 until age 50-59. Serum iPTH levels were lower in black women than in white women and usually were not measurable in oriental women. 4. In men (white, black and oriental) there was a steady decrease in mean serum calcium with age, and iPTH levels were not different from those observed in white women. 5. Although the number of samples from oriental women was small, the serum calcium was consistently lower and serum albumin was constantly higher than in white or black women, and iPTH levels usually were unmeasurable.

Adolescent↗

PubMedDate not supplied

Immunologic dysfunction: simultaneous study of Alzheimer's and older Down's patients.

Peripheral blood lymphocytes from Alzheimer's disease patients, older patients (aged 25-59 years) with Down's syndrome and closely age-matched healthy controls were tested in vitro for DNA synthesis in response to stimulation by phytohemagglutinin, pokeweed mitogen and OKT3 monoclonal antibody to T3 antigen. All were significantly decreased in Down's and Alzheimer's patients relative to healthy controls. The autologous mixed lymphocyte reaction (AMLR), unstimulated or stimulated with anti-T3. in the 2 patient groups did not differ significantly from the healthy controls. We also quantified the proportions of the T cells staining positive for surface membrane orosomucoid, and found their levels to be either higher or lower than normal in Down's patients, but not in Alzheimer's patients. These results demonstrate the existence of defective cellular immune functions in both elderly Down's patients and Alzheimer's patients.

Aged↗

PubMedDate not supplied

Progressive vertebral collapse in diffuse angiomatosis.

A case of vanishing bone disease is presented, with radiologic, endoscopic, and peritoneoscopic evidence of angiomatous involvement of the bones, surrounding soft tissues, and gastrointestinal tract. The diagnosis was made by a combination of radiologic techniques and endoscopy. Areas of absent bone were shown to opacify after intralymphatic injections of contrast material, providing in vivo demonstrations that these areas of vanishing bone are occupied by abnormal lymphatics. The etiology remains obscure, but our review of the literature suggests that this condition may be one of a large spectrum of disorders due to a basic underlying endothelial dysplasia. The lymphatic system, vascular system, or both may be involved, and the condition may manifest itself as an abnormality of the bones, soft tissues, viscera, or a combination of these.

Adult↗

PubMedDate not supplied

Immunological dysfunction in Alzheimer's disease.

Peripheral blood lymphocytes from Alzheimer's patients and apparently healthy elderly individuals were examined for interleukin-1 (IL-1) production. Our results indicate severely low production of IL-1 by patient's peripheral blood monocytes. The low production of IL-1 in vitro correlated with patients' symptoms and therapy with 1-acetamide,2-pyrrolidone (1a,2p). In addition to low IL-1 production, the number of autologous rosette forming cells (ARFC) was significantly decreased in all Alzheimer's patients whereas B-cell glucose metabolism was significantly higher than age-matched healthy individuals.

Aged↗

PubMedDate not supplied

Agglutinins for complement-coated sheep erythrocytes.

Explore the source record for details and available documents.

Agglutinins↗

PubMedDate not supplied

Antibodies to radiographic contrast agents. Induction and characterization of rabbit antibody.

An allergic, immunologic mechanism for certain adverse reactions to radiocontrast agents has been postulated on the basis of clinical and theoretical considerations. One obstacle to the acceptance of this allergic theory has been the inability to demonstrate significant antibodies with specificity for these agents. We attempted the induction of antibodies in the rabbit using analogues of radiocontrast media. The synthesis of four different analogues of commonly used radiocontrast agents allowed for testing the haptenic potential of various portions of the contrast medium molecule. Each analogue was conjugated to a carrier protein, emulsified in a suitable adjuvant, and repeatedly injected into several rabbits. Optimal immunization conditions were selected to increase the probability of antibody induction. Specific antibody was produced in good titer to each of the four haptens and in all injected rabbits. Antibodies were characterized by means of precipitation assays and radioimmunoassay using contrast agents labeled with 125I. Antibody concentrations ranged from 0.23 to 2.7 mg/ml and varied with interval and frequency of booster injections. In addition to antibodies specific for the contrast media analogues, antibodies to the carrier protein were also detected. Antibodies were of the IgG class and in selected sera were 83-92% precipitable. The induction of antibodies to radiocontrast agents supports the allergic theory of contrast medium toxicity.

Animals↗

PubMedDate not supplied