Additive Effects on the Microstructure Evolution in Hexadecyltrimethylammonium Bromide Solution and Its Rheological Properties

The effects of various additives on the microstructure evolution in hexadecyltrimethylammonium bromide micellar solution and its rheological properties are investigated. The additives considered in the present study are primary, secondary, and tertiary heptanols and sodium salicylate (NaSal). The microstructure is developed via the two-step shape transitions in the micellar solution; first, the initial spherical micelles undergo shape transition to rod-like or disc-like micelles as the micelles tend to be packed compactly with increase in the surfactant concentration; then further increment in the surfactant concentration makes the anisotropic rod-like micelles overlap each other. Solutions in these states exhibit typical non-Newtonian behaviors such as shear thinning at high shear rates. In the present study, the additive effects on the microstructure evolution are investigated by employing various techniques including a phase modulated flow birefringence, a dynamic light scattering and a dynamic oscillatory rheometry. The results show that addition of the solubilized additives enhances the microstructure transitions, which are affected by the additive concentration and its chemical structure. Presence of the cosurfactants such as heptanols with hydrophobic alkyl chains reduces the repulsion by forming surfactant-alcohol mixed micelles. The primary heptanol can penetrate easily into the micelles and aligned parallel to the surfactant molecules compared with the secondary and tertiary heptanols. Thus, the primary heptanol enhances the two-step shape evolutions more effectively than the other types. In the presence of NaSal, on the other hand, the micellar solution exhibits the viscoelastic properties and the yield stress owing to the formation of networked or worm-like micelles. Copyright 1997 Academic Press. Copyright 1997Academic Press

Probing subtle acid-induced conformational changes of ribonuclease A by electrospray mass spectrometry

The newly developed technique, electrospray mass spectrometry, was used to probe subtle conformational changes of bovine pancreatic RNase A during acid denaturation. In a dilute acid solution of pH 2.6, RNase A lost nearly all of its activity, whereas its intrinsic fluorescence intensity at 304 nm and its ellipticity at 222 nm were fairly resistant to denaturation by acetic acid. The observed maximum charged state of the enzyme in electrospray mass spectra was increased from 11+ (at pH 3.3) to 14+ (at pH 2.6). This could result from exposure of the buried basic amino acid residues R-10, K-41, H-12 and perhaps H-48.

Orientation Distribution and Electrophoretic Motions of Rod-like Particles in a Capillary

We consider motions of charged rod-like particles in a capillary under the action of externally applied electric field as a model problem for the electrophoresis through a capillary. Since the electrophoretic velocity through the capillary is dependent upon the particle orientation relative to the electric field, the probability distribution function for the particle orientation is determined from the Smoluchowski equation. In the statistical equation considered here, the random rotary Brownian potential is balanced with the potentials from both electrical and hydrodynamic origins. First, the dipole moment associated with the asymmetrical distribution of particle surface charges and that induced by the external electric field are calculated by utilizing slender body theory. The results are strictly valid under the conditions that the contribution from double-layer distortion is negligible, which is typical of charged macromolecules in aqueous media. The dipole moments are expressed in terms of the particle charge (or zeta potential) distribution, external field strength, and aspect ratio of the particle. The two distinct dipole moments incorporate into the Smoluchowski equation for the particle orientation distribution which in turn determines the electrophoretic mobility. Finally, the particle velocity in a capillary is simply given as superposition of the electrophoretic velocity and the electroosmotic velocity which is driven by the surface charges on the capillary wall.

[Preliminary observation on the destructive effect of chemical disinfectants in serum markers of hepatitis B and C]

Chloroform, 40% formaldehyde, 3% hydrogen peroxide solution and 75% alcohol were used to act on hepatitis B surface antigen (HBeAg), hepatitis B e antigen (HBaAg) and anti-hepatitis C virus antibody (Anti-HCV) positive serum for 5, 15, 30 and over 60 minutes. They were examined by enzyme-linked immunosorbent assay and observed for the effect. The destructive effect of chloroform on HBsAg and anti-HCV positive derum was marked. It was discovered that 40% formaldehyde solution destroyed HBsAg, HBeAg, and anti-HCV positive serm, while 75% alcohol also showed destructive effect on HBsAg, HBeAg and anti-HCV positive serum.

[DMSO induced differentiation of human gastric adenocarcinoma cell line MGC 80-3]

The in vitro effects of dimethyl sulfoxide (DMSO) on MGC 80-3 cells were studied by light microscopy, transmission electron microscopy and biochemical methods. The results indicated that the inhibitory effects of DMSO on the growth of MGC 80-3 cells was concentration dependent and 1.5% DMSO was suitable in the present study. The growth rate, mitotic index, colony forming efficiency and Con A-aggregation of the cells treated with 1.5% DMSO in vitro for 7 days was reduced respectively by 35.15%, 18/1000, 90% and 55.8%. It was remarkable that the activity of membrane-associated alkaline phosphatase, which is not presented in normal human gastric mucosa, was decreased by 90% in the treated cells. There was a 75% decrease of the rate of tumorigenesis in the treated cells as compared with the tumorigenic rate of the untreated MGC 80-3 cells inoculated into nude mice. Gross morphological changes of MGC 80-3 cells treated with 1.5% DMSO were evident including enlargement and flatness of the cells, stumpy microvillies instead of long and rigid ones, and extremely well-developed Golgi apparatus and rough endoplasmic reticulum. This data indicated that DMSO was able to induce differentiation of MGC 80-3 cells and change their malignant phenotypes.

[The relationship between stereoacuity and contracted visual field]

The stereoacuity (SA) was measured by means of the Titmus test, Random Dot E stereotest and Yan's stereoscopic test charts in 90 cases of glaucoma or retinitis pigmentosa with visual field contraction and 28 normal subjects. Significant reduction in SA was observed in all patients with contracted visual field, and markedly so (> 130") in cases with bilateral or unilateral tubular vision. The SA was reduced with visual field loss of over 30% and there was a positive correlation between the SA reduction and the area of visual field loss.

[Quantitative analysis of six lectin receptors and its application in differential diagnosis of astrogliomas and reactive hyperplasia of gliocytes]

The distribution of six lectin receptors (WGA, RCA-1, LCA, PSA, PNA, SBA) in 71 human astrogliomas, 8 human normal brain tissues and 11 reactive hyperplasia of gliocytes was examined by avidin-biotin-peroxidase technique and quantified with an image analysis. The results showed that WGA and RCA-1 may be used as good markers for distinguishing well differentiated astrocytomas from reactive hyperplasia of gliocytes. The quantities of LCA and PSA receptors of astrocytomas with different degree of differentiation were different. Expression of SBA and PNA receptors in normal brain tissues and different lesions was similar. The results suggest that glycoproteins and glycolipids with N-glucosidic bonds mainly changed in the process of histogenesis and differentiation of astrocytomas.

Metallic expanding biliary stents in malignant obstruction. Cases with stent in stent

We reviewed a total of 13 stent (Gianturco-Rosch biliary Z-stent) placements in 11 patients with biliary obstruction due to malignancy and report the cases treated with the stent-in-stent technique for treatment of stent occlusion due to tumor ingrowth. Causes of biliary obstruction included cholangiocarcinoma (four cases), hepatic hilar metastasis of gastrointestinal carcinoma (five cases), and pancreatic carcinoma (two cases). After transient percutaneous transhepatic biliary drainage (PTBD), the stents were successfully inserted by transhepatic route in all patients without any serious complication that needed further surgical intervention. Almost all patients were freed from the external PTBD tube about a week after stent placement and discharged from the hospital with improvement in quality of life as well as normal serum bilirubin levels. The technical advantages of stent placement include ease of insertion and the ability to drain both right and left biliary systems from a single transhepatic route by arranging the stents in a variety of configurations. Furthermore, it provides a second chance of stent placement when the previous stent has been occluded by tumor ingrowth.

[Establishment of a model of human gastric cancer with liver metastasis in nude mice]

An animal model of liver metastasis was established by injection of suspending tumor cells into subcapsule of spleen in nude mice. With additional mechanic disaggregation, single-tumor cell suspension was prepared by enzymatic disaggregation, including trypsin-collagenase disaggregate medium treatment, from the subcutaneous MGC 80-3 xeno-transplanted tumor and filtered through filter holders with different pore size. To investigate the effect of liver damage by carbon tetrachloride (CCL4) on the metastatic potential of MGC 80-3 cells injected intrasplenically, the nude mice were divided into 2 groups: Group 1 received intrasplenic injection of 1.25 x 10(6) MGC 80-3 cells without CCL4 treatment; Group 2 received intrasplenic injection of equal cells with CCL4 treatment. The incidence of liver metastasis was 60% in Group 1, but 100% in Group 2. The mean numbers of metastatic nodules per liver were 1.80 in Group 1, but 4.85 in Group 2. It is obvious that the incidence and nodules of liver metastasis were increased in the mice treated with CCL4. This is a useful model to study antimetastatic agents and metastatic behaviors.

Up-regulation of androgen receptor binding in male rat fat pad adipose precursor cells exposed to testosterone: study in a whole cell assay system

Binding of androgens to adipocytes has previously been evaluated using cytosol fractions without taking into account nuclear binding, although the latter is suggested to be close to the physiological site of action. In the present study, performed in differentiated fat pad adipose precursor cells, we describe a simple, reliable and reproducible androgen binding assay in a system with intact cells. Tritiated and unlabeled methyltrienolone (R1881) were used to define specific and unspecific androgen binding. Triamcinolone acetonide was added to prevent the binding of R1881 to other types of receptors. Differentiated adipose precursor cells contain a homogeneous class of high affinity androgen binding sites, and binding is saturable and reversible. Binding apparently occurs at one site, with a Kd in the range of physiological androgen concentration (about 4 nM). Competition studies indicate that the receptor is specific for R1881, testosterone and dihydrotestosterone, which have approximately the same affinity, while progesterone, estradiol and dexamethasone show much lower affinity. Androgen binding was markedly enhanced after cellular exposure to R1881 and testosterone but not dihydrotestosterone, and this increase was dependent on protein synthesis, suggesting the formation of new receptors by these androgens. In conclusion, fully differentiated adipocytes contain a specific, high affinity receptor, the density of which is dependent on androgens.

Identification of cyclic metabolites of isopropylated phenyl phosphates in rabbit bile

Some organophosphorous compounds, especially tri-o-cresylphosphate (TOCP), induce delay neuropathy. The cyclic saligenin phosphate (PSP) has been suggested to be the active metabolite of the protoxicant TOCP. The o-isopropylated triphenyl phosphates have been proven not to be neurotoxic. Studying the metabolism of these compounds we found the following cyclic metabolites: 2-phenyl-4H-4,4-dimethyl-1,1,3,2-benzodioxaphosphoran-2-oxide and 2-(o-isopropylphenyl)-4H-4,4-dimethyl-1,1,3,2-benzodioxaphospho ran-2-oxide. Additionally, monohydroxylated metabolites of the parent esters were detectable. The effect of glucuronidation on the formation of the cyclic metabolites is discussed in this paper.

[Oblique muscle dysfunction and cyclotropia]

The disc-fovea angle was calculated from the fundus photo by measuring the distance of fovea to the geometric center of the disc and the distance of fovea to the horizontal meridian through the disc center. The authors found the average disc-fovea angle of 40 normal individuals to be extorsion 7.43 degrees; and the diagnosis of cyclotropia was made for patients with extorsion over 14.20 degrees or intorsion, and those in whom the disc-fovea angle difference between both eyes was 8 degrees or over. In 9 cases of AV syndrome, 86% (12/14) of the V pattern cases associated with inferior oblique overaction were excyclotropic, and 75% (3/4) of the A pattern cases were incyclotropic. In 5 cases of superior oblique paresis, 86% (6/7) of the diseased eyes were excyclotropic, whether the function of the antagonistic was normal. The authors concluded that fundus photos could serve as a basis for diagnosis of cyclotropia.

[The retinal visual acuity of amblyopia]

The authors studied the relationship between the retinal visual acuity (grating acuity) and recognition acuity (E acuity) in 94 normal eyes and 169 amblyopic eyes with the results that the RVA in 84% of the normal eyes was the same as E acuity, while in 66% of the amblyopic eyes, especially the strabismic category, RVA was better than E acuity. RVA was not affected by the orientation (0 degrees, 45 degrees, 90 degrees, or 135 degrees) of the grating or the size of the light field (1.5 degrees or 3.5 degrees). Factors which could contribute to the difference between the RVA and the E acuity and the difference between strabismic and refractive amblyopia were discussed. It was put forward that grating acuity was reliable in the diagnosis of amblyopia.

[The relationship between corneal dellen and tearfilm breakup time]

In 51 patients (102 eyes) after strabismus operation, the incidence of corneal dellen was 22.54%. The average preoperative tearfilm breakup time was 28.75 sec, while the postoperative BUT in the dellen formation group was markedly reduced from the average 23.22 sec to 8.61 sec. The incidence of dellen after rectus resection (47.75%) was much higher than that after rectus recession (5.13%). It was believed that elevation of the bulbar conjunctiva after operation disturbed stability of the precorneal tearfilm to result in reduced BUT and local desiccation of the cornea, leading to dellen formation.

[Contrast sensitivity in amblyopia]

The contrast sensitivity function for sinusoid gratings of various spatial frequencies was determined for both eyes of 21 cases with unilateral amblyopia. The CSF of all amblyopic eyes except one was reduced in comparison with the non-amblyopic eye of the same person. The CS curve was depressed, especially with the middle and high spatial frequencies. The cut-off high frequency shifted toward to the left, as was the peak sensitivity. The changes in CSF with respect to different degrees of amblyopia, and the possible errors that could be made during the examination were also discussed.

A preliminary study on the use of enzyme-linked immunosorbent assay (ELISA) for detection of Trichinella spiralis infections in dogs

An enzyme-linked immunosorbent assay (ELISA) was developed to detect Trichinella spiralis infections in dogs using rabbit anti-canine IgG-horseradish peroxidase prepared according to the improved periodate method and an antigen purified from T. spiralis larvae by Sephadex G-200 chromatography. Sixty-six canine sera were tested for trichinosis by the ELISA and it showed a detection rate which was significantly higher than that by trichinoscopy. This antigen of T. spiralis appeared not to cross-react with the sera of dogs infected with Ancylostoma caninum or Taenia spp. A comparison of ortho-phenylenediamine and 5-amino-2-hydroxybenzoic acid as substrates in the ELISA did not reveal a significant difference. Pieces of filter paper saturated with a defined quantity of whole blood can be substituted for serum as a source material for the test. The relationship between worm burden and the absorbance value in ELISA is discussed.

[Endocrine cells in gastric carcinoma]

A few endocrine cells were observed in 7 of 16 specimens of gastric carcinoma studied by electronmicroscopy. They were closely mixed with other types of tumor cells infiltrating into the stroma. Some endocrine cells contained both neuroendocrine and mucous granules. This conforms well to the hypothesis that the endocrine cells as well as other types of tumor cells in gastric carcinoma, originate from the endoderm. The endocrine cells and other varieties of tumor cells were found in both intestinal and diffuse types of gastric carcinoma. The heterogeneity and histogenesis of gastric carcinoma are discussed.

[Macroscopic observation of progression of colorectal cancer]

Resected or polypectomized materials of colo-rectal cancer are morphologically analyzed in order to estimate their developing pattern. A retrospective review of previous radiological or endoscopic findings is also made in the patients who had either or both of examinations in the past. Morphologically, a distribution chart of colo-rectal cancers by their size and height is made, and a zone of colo-rectal cancers with the same morphological features is drawn. Retrospectively, type 1 advanced cancer appears to develop from Is type early cancer, and morphologically, a zone of Is type early cancers and that of type 1 advanced cancers partly overlap each other. The retrospective review also suggests that type 2 advanced cancer seems to develop from type Is, IIa or IIa + IIc early cancer. On the distribution chart, a zone of type 2 advanced cancer is partly superimposed over or bordered by that of early cancers type Is, IIa or IIa + IIc. Thus, it may fairly be said that advanced cancer develops from early cancer with its zone on the distribution chart partly superimposed over or bordered by that of the advanced cancer. Among early cancers, sessile type, superficial elevated type or elevated type with central depression may develop to advanced cancer. Both morphological analysis and retrospective radiological or endoscopic review of colo-rectal cancers would suggest the developing pattern of pedunculated or flat type early cancer.

Serum high density lipoprotein cholesterol levels in Chinese healthy subjects and patients with certain diseases

Serum high density lipoprotein cholesterol (HDL-C), total cholesterol (TC) and triglycerides (TG) were determined, and values of low density lipoprotein cholesterol (LDL-C), HDL-C/TC (%), and the LDL-C/HDL-C (ratio) were calculated in 1101 healthy Chinese men and women, 77 patients with coronary heart disease (CHD), 70 patients with cerebral vascular disease (CVD), 64 patients with diabetes mellitus (DM), 40 bilaterally oophorectomized women and 95 women using oral contraceptives. Serum HDL-C levels seemed higher and LDL-C levels lower in the healthy Chinese population as compared with those previously reported from European and American whites. Serum HDL-C was significantly higher in fertile females than in males of comparable ages. We failed to demonstrate any sharp fall in HDL-C after the menopause or bilateral oophorectomy. Serum HDL-C levels were significantly lower in both CHD and CVD patients than in healthy subjects of comparable sex and age. Concomitant increases in serum TC, LDL-C and TG, however, were found in CHD patients but not in CVD patients. No abnormality in the mean serum HDL-C level was found in DM patients. However, those complicated with CHD had significantly lower HDL-C than those without CHD. A striking serum HDL-C lowering effect was found with some kinds of oral contraceptives.