Liquid chromatographic retention behavior and separation of chlorophenols on a beta-cyclodextrin bonded-phase column, Part II. Monoaromatic chlorophenols: separation

The liquid chromatographic separation of 19 monoaromatic chlorophenols on a beta-cyclodextrin bonded-phase column is investigated in both an isocratic and a gradient elution mode. Even though the isocratic mode can be employed for the separation of the member components of each category of chlorophenols (e.g., mono-, di-, etc.), significant overlaps between the retention times of the various categories prevent the separation of all chlorophenols on a single chromatogram. Gradient elution can be used, however, for the separation of 15 of the 19 chlorophenol isomers. The unique features of gradient elution as applied to beta-cyclodextrin bonded-phase columns are discussed. The detection of chlorophenols with UV and electrochemical methods is also discussed and the two are compared.

[HPTLC densitometric determination of free bile acids in bezoar]

Cholic acid (CA), chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA) which are extracted with CH3OH from Bezoar can be separated on HPTLC silica gel plate (made in China) with isooctane-n-butyl acetate-acetic acid (4:2:1), and the three bile acids were determined by TLC densitometry.

Liquid chromatographic retention behavior and separation of chlorophenols on a beta-cyclodextrin bonded-phase column, Part I. Monoaromatic chlorophenols: retention behavior

The liquid chromatographic retention behavior of nineteen monoaromatic chlorophenols on a beta-cyclodextrin bonded-phase column is investigated with respect to mobile phase composition, pH, temperature, and ionic strength. The mechanistic aspects of retention of these compounds on the beta-cyclodextrin column are studied and compared to other reversed-phase columns. Most of the evidence suggests that the unique selectivity of this column is due to inclusion complex formation, which provides the physical basis for the resolution of positional isomers. Under certain chromatographic conditions, however, the more highly chlorinated congeners appear to be excluded from the cyclodextrin cavity; in such cases a normal-phase chromatographic mechanism is postulated, based on the interaction of the substrates with the secondary hydroxyls on the periphery of the cyclodextrin moieties.

Neodymium: YAG laser therapy in aphakic pupillary block glaucoma and aphakic malignant (ciliovitreal block) glaucoma

Aphakic pupillary block glaucoma and malignant glaucoma (ciliovitreal block) are severe complications of the intracapsular cataract extraction, presenting clinically as elevated intraocular pressure, persistent shallow anterior chamber and severe vitreal hernia. Six eyes (four women and two men) with aphakic pupillary block glaucoma and aphakic malignant glaucoma were resolved by Neodymium: YAG laser iridotomy and hyaloidotomy. The laser therapy resulted in immediate deepening of the anterior chamber and reducing of intraocular pressure. No side effect was observed. Neodymium: YAG laser iridotomy and hyaloidotomy may be more effective and simple than penetrating surgery in such cases.

[Study on the characteristics of agglutination reaction of McAb with Leptospira interrogans outer envelope]

Three McAb were produced against an outer envelope preparation from Leptospira, interrogans, serovar Lai by fusion of SP2/0 myeloma cells with immune BALB/c mice spleen cells. The fusion rate was 96% and the antibody positive rate was 50%. One of the hybridomas, E4B11C9, reacted with 13 of the 13 serovars of the Icterohaemorrhagiae serogroup in microscopic agglutination test (MAT) but did not react with the 18 representative serovars of L. interrogans and L. biflexa serovar patoc and Leptonema illini. For all non-reactive serovars the MAT titres were greater than 1:25. The McAb, E4B7G5, reacted similarly with all serovars except smithi and tonkini. E4B7D4 reacted also similarly with all serovars except serovars birkini, ndambari, bogvere, smithi and tonkini. Therefore, 3 McAb showed serogroup specificity and partial serogroup specificity by agglutination. The agglutination titres were high and hybridomas were stable, so it might be useful in providing a simple, rapid method for the classification and identification of clinical isolates such as pathogenic L. interrogans in place of the complicated and time-consuming conventional methods.

Computerized axial tomography in the diagnosis of internal derangements of the temporomandibular joint

Fourteen patients with a history of pain, clicking and locking of the temporomandibular joint were assessed clinically and by using computerized axial tomography (CAT). The findings of the clinical and CAT scan assessment were correlated and compared with surgical observations. Computerized axial tomography scanning proved to be a highly accurate method of assessing meniscal position. With the advent of more sophisticated methods of CAT scanning, it provides an accurate, non-invasive method of assessing the temporomandibular joint and providing a basis for more effective treatment planning of problems related to internal derangements.

Antitermination of characterized transcriptional terminators by the Escherichia coli rrnG leader region

We have used a plasmid antitermination test system to examine the response of an Escherichia coli rRNA operon antiterminator to transcription through Rho-dependent and Rho-independent terminator-containing fragments. We also monitored transcription through multiple copies of a terminator to explore the mechanism of rrn antitermination. Four principal observations were made about antitermination and transcriptional terminators. (1) The rrn antiterminator mediated efficient transcription through Rho-dependent terminators. (2) Under the influence of the rrn antiterminator, RNA polymerase transcribed through two and three copies of the Rho-dependent 16 S----terminator with nearly the same efficiency as through one. (3) The antiterminator had less effect on fragments containing Rho-independent terminators; the rpoC t fragment and three fragments derived from the rrnB terminator region stopped antiterminated transcription. Four other Rho-independent terminator fragments were weakly antiterminated in our test system. (4) Surprisingly, the strength of these terminator fragments was not strongly related to properties such as the -delta G or number of trailing uridine residues of their canonical Rho-independent structures, but appears to be related to additional downstream terminators. We have drawn the following conclusions from these experiments. First, that ribosomal antitermination primarily reverses Rho-dependent termination by modifying the RNA polymerase elongation complex. Transcription through a 1700 nucleotide, multiple terminator sequence showed that the antiterminator caused persistent changes in the transcription process. Second, that fragments derived from the Rho-independent rrnB and rpoBC terminator regions can effectively stop antiterminated transcription. Third, that efficient in vivo termination may often involve regions with complex multiple terminators.

[Flow cytometric analysis of DNA from 98 cases of soft tissue tumors and its clinical significance]

The cellular DNA content of 98 soft tissue tumors was determined by means of flow cytometry and the results were discussed in relation to clinical data. It was found that DNA of all 21 benign tumors was diploid, while that of malignant tumors was both diploid and aneuploid. Among 62 sarcomas, 45 were aneuploid (73%). Cell cycle analysis disclosed that diploidy lesions had a low proportion of S and G2 + M cells while most aneuploidy lesions had a high proportion (P less than 0.01). There was a definite correlation between the size of the tumor and the presence of DNA aneuploidy. The results indicate that DNA analysis offers a clinically relevant means of characterizing soft tissue tumors.

Influence of amiloride derivatives on alpha-1 adrenergic receptor-induced contractions of the rabbit aorta

Derivatives of amiloride that exhibit greater specificity for inhibition of either Na+/H+ or Na+/Ca(+)+ exchange were evaluated for their ability to influence phenylephrine (PE)-induced contractions of the rabbit aorta. Most, but not all, derivatives with alkyl substituents at the 5-amino position (which exhibit greater potency for Na+/H+ exchange inhibition) caused a dose-dependent contraction at concentrations above 10 microM. At higher concentrations and longer incubation times this contraction reached 70 to 80% of the maximal PE response. Contractions induced by 5-amino-substituted amiloride derivatives were dependent upon extracellular Ca(+)+ and were inhibited by either extracellular acidification or intracellular alkalinization. This suggests that they resulted from an influence of intracellular acidification on Ca(+)+ transport. Contractile responses to PE (1 microM) were reduced by most but not all 5-amino-substituted derivatives in conjunction with tension development. Dimethylamiloride, however, failed to cause a contraction at doses up to 100 microM but was the most potent inhibitor of PE-induced contractions among the 5-amino derivatives. Dose-response curves for PE were shifted both to the right and downward by increasing concentrations of amiloride, which indicates both competitive and noncompetitive types of inhibition. Guanidino-substituted derivatives such as benzobenzamil were the most potent antagonists, producing noncompetitive inhibition in excess of 90% at a concentration of 10 microM. The differing patterns of inhibition as well as the presence or absence of intrinsic contractile activity indicate that amiloride derivatives have the potential for multiple pathways of action that modify arterial contractility.

Targeted anti-tumor agents and their cytotoxicity on gastric cancer cells in vitro

Several chemotherapeutic drugs including methotrexate, daunomycin, mitomycin C and toxin such as ricin, A chain of ricin were chosen to conjugate with murine monoclonal antibodies MGb2 and MG11. The drugs were linked to antibody directly or through human serum albumin as intermediary. The ELISA results showed that the antibody retained well the antigen-binding capacity during conjugation. These conjugates showed highly selective cytotoxic effect on target cells. In chronic cytotoxicity tests, the cytotoxic effect of these conjugates on human gastric cancer cells KATOIII was quite similar to that of free drugs or ricin, but greater than that of irrelevant conjugates, while they had a little effect on non-target cells, suggesting that the selective cytotoxicity on target cells of the conjugates be mediated by antibodies.

[Studies on mechanism of carcinogenesis in vitro. IV. Studies on relationship between frequency of chromosome 15 monosomy and malignant expression of different clones from malignantly transformed baby hamster lung cells (BHL B4)]

The proceeding of malignantly transformed rodent cells in vitro is often accompanied by regular variation of chromosome numbers and structures. In order to clarify the relationship between them, we obtained five clones C1-1-5-from BHL B4, cell line, and analysed their biological characteristics. Results showed a positive correlation between frequency of chromosome 15 monosomy, it is suggested that suppressive gene of malignant phenotype be located on chromosome 15.

[Expression of cellular oncogenes during hepatocarcinogenesis in rats]

With RNA-DNA hybridization techniques, the mRNA expression of c-Ha-ras, c-Ki-ras, N-ras, and c-fos oncogenes in rat liver with neoplastic nodules or hepatocellular carcinoma induced by DENA was found to be higher than that in normal liver. No significant difference of c-myc expression was observed between normal liver and liver with neoplastic nodules or hepatocellular carcinoma. In the initiation stage of hepatocarcinogenesis in DENA+AAF+PH+PB and AAF+PH+PB model systems, the expression of c-myc increased markedly, and that of N-ras was remarkably stimulated under the action of AAF. It appears that a cooperative action between the c-myc and N-ras oncogenes was involved in the initiation of hepatocarcinogenesis. In the promotion stage, the expression of c-myc and N-ras returned to a normal level. The expression of c-fos decreased progressively in both the initiation and promotion stages, while that of c-Ha-ras and c-Ki-ras was not much changed. The significance of these results is briefly discussed.

Is there a circulating proteolysis-inducing factor during sepsis?

Muscles from fed or 72-hour fasted rats were incubated in the presence of plasma from septic rats, recombinant interleukin 1 alpha (rIL-1 alpha), or recombinant tumor necrosis factor alpha (rTNF alpha), and breakdown of total and myofibrillar protein was assessed by determining release of tyrosine and 3-methylhistidine, respectively. Septic plasma stimulated total protein breakdown in muscles from 72-hour fasted rats by 10% to 20%, while myofibrillar protein breakdown was not affected. When septic plasma was added to muscles from fed rats, neither tyrosine nor 3-methylhistidine release was altered. Various concentrations of recombinant interleukin 1 alpha or recombinant tumor necrosis factor alpha did not affect total or myofibrillar protein breakdown. Since septic plasma did not stimulate myofibrillar protein breakdown, the role of a circulating factor for muscle proteolysis during sepsis remains unclear.

[Stability examination of the inclusion compounds of 8 Chinese medicinal volatile oils with beta-cyclodextrin]

The content, hence the stability of volatile oils and their main components in the inclusion compounds of 8 Chinese medicinal volatile oils with beta-cyclodextrin have been examined with different storage times. The 8 Chinese medicines are Vitex negundo var. heterophylla, Notopterygium incisum, Alpinia officinarum, Atractylodes lancea, Pogostenon cablin, Asarum heterotropoides var. mandshuricum, Schizonepeta tenuifolia and Amomum villosum.

[Pancreatic glucagon receptor radioassay with liver cell plasma membrane in normal and streptozotocin-induced diabetic rats]

Pancreatic glucagon receptor radioassay has been developed with rat liver cell plasma membrane prepared with sucrose gradient centrifugation. 125I-glucagon was prepared in this laboratory and the separation of B/F was done by low speed centrifugation with addition of PEG (W/V, 20%) and normal human serum. The specific binding of 125I-glucagon was 25%-35% and nonspecific binding was less than 5%. Reproducibility within and between- assay was 6.83% and 8.40% (CV%), respectively. Binding characteristics of glucagon receptor of normal and streptozotocin-induced diabetic rats were determined by using two methods, receptor dilution and conventional competitive binding assay. The results showed that there were no marked differences concerning high and low binding affinities between normal and diabetic rats, but the concentration of binding sites for both high and low affinity receptors was significantly higher for diabetic rats than normal rats. The possible mechanisms for the above results have been discussed.

Reactivation of latent pseudorabies virus infection in vaccinated commercial sows

Pseudorabies virus (PRV) was isolated from 9 of 44 PRV-vaccinated seropositive sows on 5 of 11 farms. Although serum-neutralization antibody titers were 1:16 to 1:256, 28 virus isolates were obtained from tonsil, nasal, or buccal swab samples from 9 sows given 2 ml of dexamethasone/kg of body weight IM for 5 days. Pseudorabies virus was isolated from 6 of 20 sows (3 of 5 farms) given a killed-virus vaccination. Virus was obtained from 3 of 24 sows (2 of 6 farms) given modified-live virus and killed-virus vaccination. Evaluation of the 9 PRV with 5 restriction endonucleases revealed 4 PRV existing genotypes. The 9 isolated types of PRV appeared to be indistinguishable by Kpn I and BamHI restriction endonuclease analysis; however, when analyzed with Sal I, HinfI, and Pst I, isolates 7 (farm D), 8 (farm C), and 9 (farm B) had numerous differences. Isolates 1, 2, 3, and 4 (farm F) and 5 and 6 (farm G) appeared to be the same genotype when further analyzed with Pst I, HinfI, and Sal I.

[Studies on ultraweak luminescence of bacteria]

Ultraweak luminescence of Escherichia coli, Bacillus subtilis and Brevibacterium ammoniagenes was measured with high sensitive single photon counting equipment (Made in China). The results obtained from ultraweak luminescence of as above three bacterial strains were as follows: spectral distribution curves, photon emission kinetic curves or emission intensity and its qualitative relationship between intensity and bacterial counts.

Isolation of cDNA clones encoding small nuclear ribonucleoparticle-associated proteins with different tissue specificities

Alternative RNA processing, such as brain- and heart-specific generation of calcitonin gene-related peptide (CGRP) transcripts from the calcitonin/CGRP gene, is thought to be mediated by tissue-specific factors. We have cloned three related but distinct cDNAs encoding small nuclear ribonucleoparticle (snRNP)-associated proteins from rat PC12 cells. One clone (Sm51) has the capacity to encode a 240-amino acid protein and its RNA transcript is expressed selectively in rat brain and pituitary but not in heart. A related cDNA, designated Sm11, predicts a protein highly homologous to but distinct from Sm51. The Sm11 transcript is very abundant in heart but barely detectable in brain. Sm51 and Sm11 appear to encode the brain and heart forms of a 28-kDa snRNP-associated protein detected by anti-Sm serum, respectively. A third clone (Sm21) encodes a protein with an altered N terminus relative to Sm51. The Sm51 transcript is expressed in the pituitary, and analysis of the pituitaries of transgenic mice harboring a mouse metallothionein I promoter-calcitonin/CGRP fusion gene reveals the splice choice to be predominantly CGRP. In situ hybridization indicates Sm51 RNA is expressed throughout neuronal structures within rat brain, including the inferior colliculus, which does not possess the machinery to generate CGRP. Although Sm51 alone cannot be sufficient to account for CGRP splicing choice in all tissues, the demonstration of discrete tissue-specific expression patterns of closely related snRNP-associated proteins is consistent with their potential role in differential RNA processing events.