The metabolism of IgE. Studies in normal individuals and in a patient with IgE myeloma

IgE metabolic turnover studies with purified radioiodinated IgE were performed in normal individuals and in a patient with IgE myeloma. The validity of the turnover studies was established in several ways, including comparisons of radioiodinated IgE turnover with the turnover of endogenously labeled 14C-IgE and with the turnover of infused unlabeled IgE in a patient with hypogammaglobulinemia. The geometric mean serum IgE concentration in 73 normal adults was 96 ng/ml with a 68% confidence interval of 24 to 386 ng/ml. Metabolic turnover studies in 10 control individuals disclosed a geometric mean total circulating IgE of 4.1 mug/kg, a mean percentage of the total exchangeable IgE in the intravascular space of 41%, a mean half-time of survival of IgE of 2.7 days, a mean fractional catabolic rate of 94% of intravascular pool per day, and a geometric mean synthetic rate of 3.8 mug/kg/day. IgE has the lowest synthetic rate and highest fractional catabolic rate of the five major classes of immunoglobulin molecules. In contrast to these normal values, a patient with IgE myeloma had a serum IgE comcentration of 42 mg/ml, a total circulating IgE of 1.7 g/kg, and a synthetic rate of 270 mg/kg/day. Furthermore, although the synthetic rate was vastly increased, the survival time was prolonged and the fractional catabolic rate was decreased to 5.1 days and 16 to 22% of the intravascular pool per day, respectively. These data are compatible with the concept that IgE is catabolized in part by a mechanism common to all immunoglobulin classes and in part by a unique mechanism not available to other immunoglobulins. At very high IgE serum concentrations, such as those encountered in patients with IgE myeloma, the unique mechanism would be saturated and only the catabolic pathways available to all immunoglobulins would be available to IgE.     

Sulphure in epidermal keratohyalin granules: a quantitative assay by x-ray microanalysis

The elemental composition of different types of keratohyalin granules from the epidermis of newborn and adult rats was studied by means of an EMMA-4 analytical electron microscope, equipped with an energy-dispersive X-ray spectrometer. An absolute quantitation of the sulphur concentration in keratohyalin granules was performed. The results demonstrate that epidermal keratohyalin granules are chemically heterogeneous. A type of keratohyalin granule present in the nuclei and cytoplasm of epidermal cells from both newborn and adult rats - termed single granules - is rich in sulphur, having a content of 2-5-3-6%. Other types of keratohyalin granules, which differ in newborn and adult rats, contain a sulphur-poor component; they often have a sulphur-rich component as well. The sulphur-poor keratohyalin contains 0-6-0-9% sulphur. It is suggested that the sulphur-rich keratohyalin granules are the source of the peripheral envelope protein of cornified cells.     

Comparison of 4- and 24-hr thyroid scans with 123I: concise communication

Thyroid scans were performed at 4 and 24 hr after administration of Na123I solution in 124 examinations. The 4-hr and 24-hr scans were found to be of equal diagnostic value. Thus, in individuals with structural thyroid abnormalities, one can effectively reduce the time required for scan evaluation from the standard 24 hr to 4 hr.     

An improved method for detecting passive pills

One of the principal disadvantages of the passive pill as a telemetric method for measuring various physiological parameters has been its resticted range. The reasons for the restricted range with existing detection methods are discussed. An improved method using a locking spectrometer based on third-order phase-sensitive detection is described and its performance is assessed. A significant increase in the usable range of a high sensitivity passive pill is obtained.     

精炼工艺对椰子油品质的影响

研究了精炼工艺对椰子油品质的影响。分析了毛椰油、碱炼油、脱色油、脱臭油的理化指标、脂肪酸、甘油酯组成和脂肪伴随物(甾醇、生育酚、多酚)的变化情况。结果表明:精炼工艺使椰子油的酸值、过氧化值显著降低,脂肪酸和甘油酯组成无显著变化;总甾醇、总生育酚和多酚含量显著降低,损失率分别为63.77%、68.03%、71.20%。综上表明,精炼能够显著影响油脂品质,需注重油脂适度加工技术的应用。     

Self-inhibition in amiloride-sensitive sodium channels in taste receptor cells

Recognition of antigen by T cells requires the formation of a specialized junction between the T cell and the antigen-presenting cell. This junction is generated by the recruitment and the exclusion of specific proteins from the contact area. The mechanisms that regulate these events are unknown. Here we demonstrate that ligand engagement of the adhesion molecule, CD2, initiates a process of protein segregation, CD2 clustering, and cytoskeletal polarization. Although protein segregation was not dependent on the cytoplasmic domain of CD2, CD2 clustering and cytoskeletal polarization required an interaction of the CD2 cytoplasmic domain with a novel SH3-containing protein. This novel protein, called CD2AP, is likely to facilitate receptor patterning in the contact area by linking specific adhesion receptors to the cytoskeleton.     

Loss of H19 imprinting and up-regulation of H19 and SNRPN in a case with malignant mixed Müllerian tumor of the uterus

An unusual clinical presentation of a patient with neuronal intestinal dysplasia is presented. A 46-year-old male noted a palpable mass in the right lower quadrant of his abdomen for two months. A computed axial tomographic scan showed a thickened wall of the cecum with a tumor-like appearance. The excised specimen consisted of a mass caused by the thickened, edematous wall of the dilated cecum and appendix. The wall of the cecum and appendix measured up to 2.5 and 0.8 cm, respectively, in thickness. Microscopic studies showed extensive hyperplasia and hypertrophy of the ganglia and nerve plexuses and hypertrophy of the muscularis propria, consistent with neuronal intestinal dysplasia.     

不同比例LA/ALA对HepG2细胞炎症因子的影响

选取植物油中典型的多不饱和脂肪酸亚油酸(LA)和α-亚麻酸(ALA)为原料,分为7个不同摩尔浓度配比实验组(组1,LA;组2,10∶1 LA/ALA;组3,5∶1 LA/ALA;组4,1∶1 LA/ALA;组5,1∶5 LA/ALA;组6,1∶10 LA/ALA;组7,ALA)体外评估不同比例n-6/n-3 PUFAs对HepG2细胞炎症因子的影响。结果表明:60μmol/L各实验组均可降低HepG2细胞产生的促炎因子TNF-α和IL-6水平,提高抗炎因子IL-10和抗炎介质LXA4水平,其中组4(1∶1 LA/ALA)作用最显著。