[The evaluation of thyroid suppression test in predicting the outcome of Graves' disease treated by short-term antithyroid drugs]

One hundred and fifteen new patients with Graves' hyperthyroidism were received thyroid suppression test after cessation of 6 month course of drug therapy. The results of follow up for another 12 months were that one of them had lost, 48 cases were in remission, and 66 cases had relapsed. The present study shows that thyroid suppression test, including the 4th, 6th and 24th hour suppression rates, is useful in predicting the outcome of drug therapy. The effect of 6th hour suppression rate is better than that of 24th and 4th hours, with 75.8% sensitivity, 75.0% specificity and 75.4% accuracy when 30% of thyroid suppression rate is as out-off point which is decided by ROC curve. It is suggested that 6 hour 30% suppression rate is better than the traditional 24 hour 50% suppression rate in the prediction of outcome of drug therapy.

[A preliminary study of the inhibiting mechanism of anisodamine on rabbit platelets activated by E. coli endotoxin]

Bacterial endotoxin binds to platelets and causes platelet aggregation, thrombocytopenia, increase in thromboxane A2 production, serotonin release and increase in the generation of platelet factor 3 procoagulant activity. These effects have been demonstrated in a variety of animal species. Much evidence has shown that such changes may participate in the pathogenesis of DIC and RDS in septic shock. The anisodamine (654) antishock effect has been studied from different angles for more than 20 years, with its effect on the cardiovascular system, including the microcirculation, being demonstrated. But few reports concerning its effect on platelet function have emerged. In this study, the effect of anisodamine on rabbit platelet aggregation, release, morphological changes, cellular cAMP, and membrane lipid fluidity induced by E. coli endotoxin were studied both in vivo and in vitro. After anisodamine intervention, all of these parameters improved to a certain extent. The possible protective mechanisms of anisodamine on platelets both in vivo and in vitro are discussed.

[Enhancing effect of chuangxinmycin on synthesis of enzymes in tryptophan synthesis pathway of chuangxinmycin-resistant mutant strain of E. coli]

Chuangxinmycin (CXM) and L-trp cause repression of trp-operon in wild strain of E. coli and indolepropanic acid (IPA) causes derepression of this strain. In CXM-resistant mutant strain, CXM and IPA both cause derepression, and interaction of CXM and IPA is competitive. However, L-trp results in neither repression nor derepression in the mutant, but it can counteract the activity of CXM or IPA. These results suggest that there are repression and derepression sites on repressor of E. coli. CXM can bind to both sites, but mainly to repression site. The structure of repression site of the CXM-resistant mutant is altered, so that CXM can not bind to the repression site and binds mainly to the derepression site, thus leading to the derepression of trp-operon.

[Separation of 20(S)-ginsenoside-Rg2 and its 20(R) epimer by reversed phase low pressure column (Rp-18) chromatography]

20(S)-Ginsenoside-Rg2 and its 20(R) epimer were successfully separated using reversed-phase low pressure column (Rp-18) chromatography. The method has proved very convenient and rapid.

Decrease of anion selectivity caused by mutation of Thr501 and Gly502 to Glu in the hydrophobic domain of the colicin E1 channel

Structure-function relations of the colicin E1 ion channel were studied through the effects of mutations in the 35-residue hydrophobic region of the channel polypeptide and neighboring residues in the channel domain. Mutation of neutral residues threonine 501 and glycine 502 to a more polar or charged glutamic acid generated a protein whose channel conductance properties in each case had a decreased selectivity for anions. There was no significant effect on ion selectivity caused by mutations that changed residue charge outside the hydrophobic domain at the neighboring aspartic acid 509 or at glycine 439. The Thr501----Glu and Gly502----Glu mutants possessed lower cytotoxic and in vitro activity. An altered thermolysin cleavage pattern and a greater binding to membrane vesicles at pH greater than 4.5 of the Gly502----Glu mutant indicated greater exposure of its COOH-terminal hydrophobic domain in solution. It is concluded that the hydrophobic nature of threonine 501 and glycine 502 is important in the structure of the channel lumen and the soluble colicin. Altering proline 462, a residue conserved in five sequenced channel-forming colicins, had no significant effect on channel properties. These conclusions are discussed in the context of sequence-structure-function concepts for channel proteins.

Pinhole hologram and its applications

We propose the use of a pinhole-camera approach to make holograms. On recording the object beam passes through a pinhole, forming an image plane hologram, but on reconstruction the pinhole can be taken away. The reconstructed image can be programmed and processed by using optical information-processing elements placed in the position of the reconstructed pinhole or pinholes. Pinhole holography can also suppress intermodulation effects. We present brief theoretical considerations and experimental results for pinhole holograms produced for programmable holographic optical interconnects.

Deep-red holography using a junction laser and silver-halide holographic emulsion

We have investigated exposure parameters for deep-red holography using a junction laser and silver-halide holographic emulsion to record single-beam reflection phase-volume holograms recorded and reconstructed at a wavelength of 750 nm. We present measurements of the variation of diffraction efficiency and its derivative efficiency with exposure energy. These measurements are compared with the corresponding values obtained when using a He-Ne laser for recording; similar diffraction efficiencies have been obtained with both kinds of laser.

Dynamic properties of membrane proteins: reversible insertion into membrane vesicles of a colicin E1 channel-forming peptide

The binding of colicin E1 and its COOH-terminal channel-forming peptides to artificial membrane vesicles has an optimum at acidic pH values. The Mr 18,000 thermolytic peptide inserted into membrane vesicles at pH 4.0 has a limited accessibility to exogenous protease. It is converted by trypsin cleavage after Lys-381 and Lys-382 to a lower Mr 14,000 peptide. However, when the pH of a vesicle suspension to which peptide has been bound at pH 4.0 is shifted to 6.0, the accessibility to protease increased greatly. This was shown (i) by the large decrease in the amount of Mr 14,000 or Mr 18,000 peptide after the pH 4----6 shift and treatment with trypsin or Pronase, consistent with (ii) a previously observed decrease in membrane-bound radiolabeled peptide after protease treatment. (iii) When a photoactivable nitrene-generating phospholipid probe was used to label the colicin peptide inserted into the bilayer, the extent of labeling decreased by a factor of 3 when the pH was shifted from 4.0 to 6.5. (iv) Colicin peptide added to vesicles at pH 4.0 can "hop" to other vesicles if the pH and ionic strength of donor vesicles are successively increased. It is proposed that deprotonation of acidic residues in contact with the hydrophobic bilayer or the membrane surface destabilizes the inserted channel and causes it to be extruded from the membrane. The pH-dependent extrusion of the inserted colicin channel provides an example of dynamic properties of an intrinsic membrane protein.

Sympathetic ophthalmia. An immunohistochemical study of epithelioid and giant cells

There is controversy regarding the origin of the pigment-containing epithelioid cells in the uvea of eyes with sympathetic ophthalmia. The results of the present immunocytochemical study demonstrating the presence of muramidase and S-100 protein in these cells, and the binding of peanut lectin by the pigment-containing cells support the interpretation that the pigment-containing epithelioid cells and giant cells are of monocytic (histiocytic) origin. Our study also emphasizes the diverse functional capacity of these epithelioid cells.

Culture requirements of Ascaris suum larvae using a stationary multi-well system: increased survival, development and growth with cholesterol

Ascaris suum third-stage larvae (L3) were recovered from infected rabbits and cultured in a stationary multi-well plate system. Several different culture media including Medium 199, NCTC-135, Minimum Essential Medium-Eagle, Dulbecco's Modified Eagle's Medium, RPMI 1640, McCoy's 5A and Neuman-Tytell medium were tested to determine which was best for overall larval survival, development and growth. Larvae developed from L3 to fourth-stage (L4) in all media tested, but larval survival and the yield and growth of L4 were superior in RPMI 1640. Pyruvate is an important medium component because its addition to RPMI 1640 enhanced the yield and growth of L4 while its removal from DMEM reduced larval survival and the yield and growth of L4. Cholesterol markedly enhanced larval survival and the yield and growth of L4 when added to RPMI 1640 as either a soluble supplement in Tween 80 or to a lesser degree, as a component of liposomes. The multi-well culture plate system is a convenient method for determining the effects of different media and changes in media composition on larvae in vitro.