Characteristics of two-dimensional and color Doppler ultrasonography in Graves' disease

Color Doppler flow imaging (CDFI) was performed in 24 patients with Graves' disease and the results were compared with those from 8 patients with Hashimoto's disease, 6 patients with simple diffuse goiter, and 15 normal volunteers. All cases were confirmed by clinical, laboratory tests or pathology. CDFI of Graves' disease showed diffuse or localized hypoechoes within the thyroid glands, rich flow signals in the hypoechoes, accelerated flow velocity, and decreased resistance in the superior thyroid arteries (STA) and arteries within the glands. These appearances were characteristic as compared with the controls. The rate of flow in STA of Graves' disease patients was 8 to 10 times higher than that in the normal volunteers. This study demonstrates that CDFI is convenient and efficient as compared with isotope scan and some other laboratory tests, and can be widely used in the diagnosis of Graves' disease.

Measurement of the geometric parameters of the aortic bifurcation from magnetic resonance images

This paper presents a method for measuring arterial geometry in vivo using MRI. The approach was validated using MR images of three perfused compliant casts of human aortic bifurcations whose geometry was known. Preliminary human studies demonstrated the reproducibility of the technique. The approach was applied to 20 normal individuals to study the effects of age, race, and gender on the geometry of the aortic bifurcation. The results show that older people tend to have a smaller bifurcation angle, lower planarity, and larger angular asymmetry than younger people. Asians have larger bifurcation angles than whites. The bifurcation of males is more asymmetric than that of females. These results may have implications regarding the heritability of arterial geometry, the similarities of cardiovascular risk within families, and differences in risk among groups.

Body segment growth during infancy

In order to better understand relationships between physical growth and motor development during infancy, changes in segment inertias were examined. A rationale based on dynamic systems theory and intersegmental moments was used to select the variables: the segment mass and principal moments of nine segments. The hypothesis was that there are differences in growth velocity between segments and these are consistent with the principles of cephalocaudal development and distal to proximal growth. A mathematical model of the segments was used to examine changes of the inertia parameters. Twenty-seven normal infants carried to full term and aged between 2 and 9 months at the beginning of the study were photographed once a month for 6 months. Outlines of segments from front and side 35 mm images were digitized and mass and principal moments of inertia estimates obtained. Polynomial regression was used to give the development curves regression coefficients for the 155 data points. Also, linear regressions were fitted to the six growth data points of each subject. Most of the relationships between chronological age and segment mass and principal moments were significant and linear. The differences in growth velocity between segments were significant and partially consistent with the growth principles. However, there were considerable differences, in particular for the lower trunk and the shank, where it appears that growth may be irregular until after the age of 15 months.

Free radical mechanism in enhancement of radiosensitization by SRSBR

The free radical mechanism of enhancing radiosensibility by the Synergic Recipe to Strengthen Body Resistance (SRSBR) consisting of 10 Chinese drugs was studied by electron spin resonance (ESR) with spin trapping reagent--Nitroso-tert-butane (NtB) following irradiation of the Deoxy thymidine (dT) solution system by 60Co 3.7 PBq. The results showed SRSBR cannot only enhance the generation of e- aq but also enhance the production of . OH and H . after irradiation with gamma ray in dT-NtB-SRSBR aqueous solution system. These result in damage to biological molecules, attacking and killing tumor cells radiosensitized by SRSBR. The characteristics of SRSBR for radiosensitization are concluded to be increasing production of . OH and H. in comparison with the well-known radiosensitizer-Misonidazole (Miso).

MKP-1 (3CH134), an immediate early gene product, is a dual specificity phosphatase that dephosphorylates MAP kinase in vivo

Mitogenic stimulation of cells induces rapid and transient activation of MAP kinases. Here we report that a growth factor-inducible gene, 3CH134, encodes a dual specificity phosphatase that dephosphorylates and inactivates p42MAPK both in vitro and in vivo. In vitro, 3CH134 protein dephosphorylates both T183 and Y185 in p42MAPK. In serum-stimulated normal fibroblasts, the kinetics of inactivation of p42MAPK coincides with the appearance of newly synthesized 3CH134 protein, and the protein synthesis inhibitor cycloheximide leads to persistent activation of MAP kinase. Expression of 3CH134 in COS cells leads to selective dephosphorylation of p42MAPK from the spectrum of phosphotyrosyl proteins. 3CH134 blocks phosphorylation and activation of p42MAPK mediated by serum, oncogenic Ras, or activated Raf, whereas the catalytically inactive mutant of the phosphatase, Cys-258-->Ser, augments MAP kinase phosphorylation under similar conditions. The mutant 3CH134 protein also forms a physical complex with the phosphorylated form of p42MAPK. These findings suggest that 3CH134 is a physiological MAP kinase phosphatase; we propose the name MKP-1 for this phosphatase.

The growth factor-inducible immediate-early gene 3CH134 encodes a protein-tyrosine-phosphatase

Stimulation of fibroblasts with serum growth factors results in the rapid activation of a set of immediate-early genes, among them 3CH134. We have purified a bacterially expressed form of the 3CH134-encoded polypeptide and demonstrated that it has intrinsic protein-tyrosine-phosphatase (PTPase; protein-tyrosine-phosphate phosphohydrolase, EC 3.1.3.48) activity in vitro. This activity is optimal at pH 7.5, is sensitive to vanadate and cysteinyl modifying agents, and is insensitive to a panel of serine/threonine phosphatase inhibitors. Purified 3CH134 protein displays a high degree of selectivity among the tyrosine-phosphorylated polypeptide substrates tested. Under our assay conditions, the rates of dephosphorylation are in the order EDNDYINASL peptide < myelin basic protein < reduced, carboxyamidomethylated, and maleylated lysozyme (RCML) < p42mapk. There is a 200-fold range in rates for these substrates, with p42mapk dephosphorylated 15-fold more rapidly than RCML. Although 3CH134 is most closely related to the tyrosine/serine dual-specificity phosphatase VH1, we failed to detect any 3CH134-directed activity on casein or RCML phosphorylated on serine/threonine residues by cAMP-dependent protein kinase. Since 3CH134 expression is controlled transcriptionally and posttranscriptionally, it may represent a class of PTPases whose activity is regulated at the level of protein synthesis and degradation.

Serum protein-binding characteristics of vancomycin

A synthesis of studies of serum protein binding of vancomycin and its reported abnormal binding in serum with very high concentrations of immunoglobulin A (IgA) suggests that this antibiotic may be bound to more than one serum protein. Using an ultrafiltration method for separating free from bound drug and high-performance liquid chromatography to measure drug concentration, we studied the binding characteristics of vancomycin for alpha-1 acid glycoprotein, IgG, IgM, IgA, and albumin. The results showed that vancomycin does not bind to alpha-1 acid glycoprotein, IgG, or IgM. Major binding to albumin and IgA occurs, and total drug binding to serum proteins can be fully explained by binding to these two proteins. We calculated an N (number of binding sites per molecule) of 1.3 +/- 0.4 and a K (association constant) of 3.3 x 10(5) +/- 6.3 x 10(4) M-1 (NK = 4.3 x 10(5) M-1) for binding to IgA, whereas the corresponding NK value for albumin was only 527.5 M-1, indicating that vancomycin preferentially binds to IgA. Very high concentrations of IgA in serum (i.e., grams per deciliter), such as in patients with IgA myeloma, may result in the paradox of high (total) concentrations of vancomycin in serum that may be clinically ineffective.

A protein-tyrosine/serine phosphatase encoded by the genome of the cyanobacterium Nostoc commune UTEX 584

Protein-tyrosine phosphorylation has long been regarded as an exclusively eukaryotic phenomenon. Although some non-eukaryotes, mainly viruses, possess genes encoding protein-tyrosine kinases or protein-tyrosine phosphatases, these were probably appropriated from the eukaryotic hosts that constitute the sites of action of these enzymes. Herein we identify a gene, iphP, from the chromosome of the cyanobacterium Nostoc commune UTEX 584 that contains the His-Cys-Xaa-Ala-Gly-Xaa-Xaa-Arg sequence characteristic of known protein-tyrosine phosphatases. The expressed gene product, IphP, displayed protein-tyrosine phosphatase activity toward phosphotyrosine residues on reduced, carboxyamidomethylated, and maleylated lysozyme with optimum activity at pH 5.0. In addition, IphP dephosphorylated the phosphoseryl groups on casein that had been phosphorylated by the cAMP-dependent protein kinase. Cell lysates of N. commune probed with antibodies to phosphotyrosine indicated the presence of a tyrosine-phosphorylated protein of M(r) approximately 85 kDa. This tyrosine-phosphorylated protein was detected in cells grown in the presence of combined nitrogen but not in nitrogen-deficient media that induces the formation of differentiated N2-fixing cells (heterocysts). Together, these data suggest a role for protein-tyrosine phosphorylation in regulating cellular functions in this cyanobacterium. IphP is the first protein-tyrosine phosphatase to be discovered that is encoded by the chromosomal DNA of any prokaryote. Given the free-living nature of N. commune and the phylogenetic antiquity of the cyanobacteria, these findings suggest for the first time the existence of a protein-tyrosine phosphatase of genuine, unambiguous prokaryotic ancestry, thus raising fundamental questions as to the origin and role of tyrosine phosphorylation.

[Ureaplasma urealyticum and intrauterine infection of fetus]

Ureaplasma urealyticum (Uu) infection in pregnancy can lead to a poor outcome. To confirm the relation between Uu and intrauterine infection, 65 placentas were taken for isolation and identification of Uu from pregnant women with positive antibody to Uu. Uu was isolated from 13 (20%) of the 65 placentas. The pathologic examination of 6 placentas showed that there were acute or chronic inflammatory cell infiltration. Cord blood IgM antibody was examined by ELISA from 5 cases in which Uu was isolated from placentas and 3 of them was positive to Uu. The 5 cord blood specimens were assayed by the metabolic inhibition test for serotypes of Uu, and one of them was serotype 8. Since the isolation of Uu from some pregnant women, the pathologic changes of placentas, and the detection of specific IgM from cord blood showed a good consistency, we conclude that the Uu infection may occur in utero.

Atrial natriuretic peptide inhibits growth of hepatoblastoma (HEP G2) cells by means of activation of clearance receptors

To investigate whether atrial natriuretic factor regulates the growth of hepatocytes and to determine the receptor subtype involved in such modulation, we studied the effect of atrial natriuretic factor 103-126 and clearance receptor binding analogs of atrial natriuretic factor, (des-(Q116, S117, G118, L119, G120) atrial natriuretic factor 102-121 and des-(C105,121) atrial natriuretic factor 104-126) on growth of human hepatoblastoma cells. Atrial natriuretic factor 103-126 and des-(Q116, S117, G118, L119, G120) atrial natriuretic factor 102-121 inhibited thymidine incorporation into human hepatoblastoma cells cultured in the presence of bovine serum albumin and epidermal growth factor but not in cells cultured in bovine serum albumin alone. Moreover, atrial natriuretic factor 103-126, des-(Q116, S117, G118, L119, G120) atrial natriuretic factor 102-121 and des-(C105,121) atrial natriuretic factor 104-126, in a concentration-dependent manner, inhibited thymidine incorporation and cell proliferation. As monitored by the ability of des-(Q116, S117, G118, L119, G120) atrial natriuretic factor 102-121 to displace 125I-labeled atrial natriuretic factor, epidermal growth factor increased the expression of cell surface clearance receptors. Epidermal growth factor also transiently increased the cellular content of atrial natriuretic factor clearance receptor messenger RNA without altering the levels of guanylyl cyclase-linked atrial natriuretic factor receptor messenger RNA levels. Maximal increase in atrial natriuretic factor clearance receptor messenger RNA coincided with the maximal increase in des-(Q116, S117, G118, L119, G120) atrial natriuretic factor 102-121-displaceable 125I-atrial natriuretic factor binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)