[Simultaneous determination of gibberellins A1 and A3 in foxtail millet seedlings by high performance liquid chromatography]

Gibberellin A1(GA1) and Gibberellin A3(GA3) in millet seedlings were simultaneously determined by HPLC on a Zorbax-ODS-C18 (4.6 mm x 250 mm, 10 microns) column, using a mobile phase consisting of V (0.02 mol/L phosphate buffer solution, pH 4.0):V(methanol) = 2.2:1, a flow rate of 0.8 mL/min and a UV detection at 210 nm. GA1 and GA3 were separated completely in 10 min. Correlation coefficients for linear equations were 0.9986 and 0.9978, recoveries were 102.54% and 99.59%, respectively. Two normal cultivars and their dwarf-mutants were determined by this method. The results showed that both GA1 and GA3 were discovered in foxtail millet seedling, and endogenous mass ratio of GA1 and GA3 in foxtail millet dwarf-mutants were significantly lower than those in normal cultivars, and the concentrations of endogenous GA1 and GA3 were important factors for plant-height.

[Molten organic salt--a new class of stationary phases for GC]

Molten organic salts are a new class of polar, selective stationary phases for gas chromatography. Their types and characters are reported in detail and compared with some common stationary phases.

Aberrant positioning of trophoblast and lymphocytes in the feto-maternal interface with pre-eclampsia

Pregnancy represents the growth of an allograft where fetal trophoblast cells evade immune rejection and invade maternal tissue. There should be a balance between fetal trophoblast and maternal immune-responsive cells and alterations in the proportion of these cells may relate to pregnancy disorders. To test this, the decidual tissue of placental bed biopsies was examined and trophoblast cells and lymphocytes were quantified morphometrically; spiral arteries were classified as unchanged, transformed or affected by acute atherosis. Normal pregnancy (n=19) was characterized by the transformation of about one half of all spiral arteries within the placental bed. We found that 40% of all lymphocytes were CD56+ uterine NK cells and 60%, CD3+ T-lymphocytes; about 30% of these were CD8+ T cells. Intrauterine growth retardation in the context of preeclampsia (n=15) was accompanied by reduced trophoblast numbers within smaller and more tortuous arteries and an increase in the proportion of CD56+ uterine NK cells and CD8+ T lymphocytes in the decidua (70% of all CD3+ cells). In the case of pre-eclampsia without fetal growth retardation (n=14) no increase in CD56+ uterine NK cells was seen, while CD8+ T lymphocytes were significantly increased compared with the normal level (50% of all CD3+ cells). Fetal growth retardation is associated with poor transformation of spiral arteries and characterized by an increase of uterine NK cells. Symptoms of pre-eclampsia are independently associated with an increase in the cytotoxic T subset of decidual lymphocytes. Pre-eclampsia and related fetal growth retardation are seemingly caused by an enhancement of the maternal cytotoxic defence against the fetal allograft.

[Clinical analysis of 19 cases of scleroma respiratorium treated surgically]

Nineteen patients with scleroma respiratorium treated surgically were studied retrospectively. The results suggested that the surgical operation combined with antibiotic therapy were beneficial to the curtive effect of the patients in the granulomatous stage with nasal or pharyngeal obstruction or nasal sinuses involvement due to the serious proliferation of the lesions; tracheotomy should be considered in the patients with laryngeal obstruction up to the second degree or above; plastic operations were necessary for the patients with cicatrical stenosis or imperforation remained of the nasal cavity, pharynx, larynx or trachea.

Targeted lymph-node immunization with whole inactivated simian immunodeficiency virus (SIV) or envelope and core subunit antigen vaccines does not reliably protect rhesus macaques from vaginal challenge with SIVmac251

OBJECTIVE

Sexual transmission of HIV is the most common route of HIV transmission throughout the world. To prevent sexually transmitted HIV infection, a vaccine is urgently needed. A previous report demonstrated the targeted immunization of the iliac lymph nodes with simian immunodeficiency virus (SIV) subunits protects rhesus macaques from rectal challenge with SIV. We sought to determine whether this immunization strategy could protect rhesus macaques from vaginal challenge with SIV.

DESIGN

Macaques were immunized with either whole-killed SIV or envelope and core subunit antigen vaccines. Using three independent groups, with three macaques in each group, macaques were immunized by the targeted iliac lymph-node (TILN) route, injecting the vaccine close to the iliac lymph nodes that drain the genital tract.

RESULTS

The TILN immunization procedure induced high-titer SIV-specific immunoglobulin (Ig) G antibodies in serum in all animals and anti-SIV IgG and IgA antibodies in the cervicovaginal secretions of most animals. After a series of three or four TILN immunizations, the animals were intravaginally challenged with SIVmac251. All animals became virus isolation-positive, except one animal immunized with SIV p27 and gp120. This animal was virus isolation-negative but SIV DNA proviral sequences were detected in peripheral blood mononuclear cells.

CONCLUSIONS

In this series of studies, reliable protection from vaginal transmission of SIV was not achieved by the TILN immunization procedure.

[Molecular cloning of the imipenem resistant gene in bacteroides fragilis]

Imipenem, as a representative of-cabapenem, is one of the most effective beta-Lactam agents against Bacteroides, but recently there have been a few reports on the resistant strains of Bacteroides. To explore the mechanism of imipenem resistance (IMPr) at the molecular level, we extracted chromosome DNA of the resistant strains and acquired a 1.7 kb fragment of resistant gene of imipenem. Recombinant plasmid was stably reserved in generation after generation in E. coli DH5. Resistant gene of imipenem was labeled with Dig-11-dUTP by way of random prime, and 40 strains of clinically isolated Bacteroides were detected by the prepared DNA probe. Two IMPr strains showed hybridization signal, whereas 38 IMPr strains did not show such a signal. The result suggests that the Dig-labeled IMPr gene probe can be used in molecular epidemiology for investigating IMPr strains.

Rhesus macaques previously infected with simian/human immunodeficiency virus are protected from vaginal challenge with pathogenic SIVmac239

Nontraumatic vaginal inoculation of rhesus macaques with a simian/human immunodeficiency virus (SIV/HIV) chimera containing the envelope gene from HIV-1 89.6 (SHIV 89.6) results in systemic infection (Y. Lu, B. Brosio, M. Lafaile, J. Li, R. G. Collman, J. Sodroski, and C. J. Miller, J. Virol. 70:3045-3050, 1996). A total of five rhesus macaques have each been infected by exposure to at least three intravaginal inoculations of SHIV 89.6. The SHIV 89.6 infection is characterized by a transient viremia that evokes humoral and cellular immune responses to HIV and SIV antigens, but disease does not develop in animals infected with SHIV 89.6. To determine if a previous infection with SHIV 89.6 by vaginal inoculation could protect animals from vaginal challenge with pathogenic SIV, all five animals were intravaginally inoculated twice with pathogenic SIV-mac239. After challenge, all of the SHIV-immunized animals had low or undetectable viral RNA levels in plasma compared to control animals. Three of the five of the SHIV-immunized animals remained virus isolation negative for more than 8 months, while two became virus isolation positive. The presence of SIV Gag-specific cytotoxic T lymphocytes in peripheral blood mononuclear cells and SIV-specific antibodies in cervicovaginal secretions at the time of challenge was associated with resistance to pathogenic SIV infection after vaginal challenge. These results suggest that protection from sexual transmission of HIV may be possible by effectively stimulating both humoral and cellular antiviral immunity in the systemic and genital mucosal immune compartments.

Image cytometric DNA analysis of adrenocortical neoplasms as a prognostic parameter: a clinico-pathologic study of 13 patients

Formalin-fixed paraffin-embedded material of thirteen adrenocortical neoplasms were examined by conventional microscopy, and by DNA image cytometry in Feulgen-stained tissue sections and cytospin preparations. The subsequent clinical course of each patient was reviewed. Seven of the neoplasms were classified according to the histologic criteria of Weiss as adenomas and six as carcinomas. The DNA content and indices of all 13 adrenocortical neoplasms were measured by image cytometry. For the internal standard, the DNA values of the adjacent normal adrenal cells in 10 cases and of nuclei of fibrocytes of the tumour stroma were determined. DNA values in all seven adenomas, in normal adrenal cells, and in the nuclei of fibrocytes were unequivocally diploid. The six carcinomas expressed aneuploid, tetraploid or hypertetraploid DNA values. DNA values of normal adrenal cells seemed to provide a better internal control than those of connective tissue cells. Of the seven adenoma patients with a follow-up between 8 and 124 months (mean 59 months), six were alive without evidence of tumour; one patient died from other causes. Of the six carcinoma patients with a follow-up ranging from 5 days to 36 months, three patients died from the disease; one patient was alive with metastases, and only two patients were alive without evidence of the disease for 25 and 36 months, respectively. Our results strongly suggest that image cytometric DNA analysis is a valuable method to distinguish between benign and malignant adrenocortical neoplasms.

[Effect of birchdust on viability of alveolar macrophages and superoxide produced by alveolar macrophages in vitro]

Rabbit alveolar macrophages (AM) in vitro were used as a model in this wooddust toxicological experiment to study the effect of birchdust with different concentrations and exposure durations on the viability of AM and superoxide produced by AM. The results showed that the viability rates in three birchdust groups (400, 800, 1600 micrograms/ml) gradually decreased when the concentration at all the designed exposure durations (12, 18, 24 h) increased except the rates for the 6-hour period. On the contrary, the contents of superoxide (O2-.) at the first two durations (6, 12 h) increased rapidly and reached their highest level at the 18 hours. Moreover, the rapid increase of O2-. preceded the declination of viability rates, suggesting that birchdust toxicity in AM in vitro be probably related to dust-induced O2-. produced by AM.

[Labeling DNA probe by polymerase chain reaction]

The use of polymerase chain reaction (PCR) for labeling probe has been demonstrated to offer various advantages including efficient labeling of DNA fragments as small as 72 bp, direct labeling of genomic DNA, and labeling with subnanogram amounts of input DNA. Therefore, a procedure for the nonradioactive labeling of chromasomal DNA 203 bp fragments of Helicobacter pylori with the hapten digoxigenin (Dig) by PCR has been developed. The results showed that the concentration of probe labeled by PCR was much higher than that by random primer labeled. PCR has the advantage of rapidity and economy. It is a very effective technique for synthesis of Dig-labeled DNA probe.

[The relationship between the high inducibility genotype of CYP450IA1 and lung cancer susceptibility]

OBJECTIVE

To evaluate the role of polymorphism of CYP450IA1 gene in the susceptibility of lung cancer.

METHODS

The polymorphism of CYP450IA1 gene in 149 lung cancer patients and 208 healthy controls were investigated by PCR technique.

RESULTS

The high inducibility genotype (Val/Val type) of CYP450IA1 in lung cancer patients was 16.1%, which was significantly higher than that of controls, 8.7%. According to pathological classification of lung cancer, it was indicated that VAl/Val type in squamous carcinomas was the highest, 21.54%, which was significantly higher than that of controls (8.7%) and adenocarcinomas (8.00%). The Val/Val type in small cell carcinoma reached 17.6%. The relative risks were estimated according to smoking condition and CYP450IA1 genotype. Taking the risk of the category with non-smoking and non-high inducibility genotype (Val/ Val) to be at a baseline of 1.0, the odds ratio was 1.6 (P < 0.05) in non-smoking in non-smoking and Val/Val type 4.8 in smoking and Val/Val type (P < 0.001). The relative risk of Val/Val type was 2.2 times as non-Val/ Val type for smoking people.

CONCLUSIONS

Development of lung cancer was associated with the high inducibility genotype of CYP450IA1. And Val/Val genotype of CYP450IA1 gene might be an important host hereditary marker for susceptibility to lung cancer.

Variation of intrarenal angiotensin II and angiotensin II receptors by acute renal ischemia in the aged rat

The properties of Ang II receptors in the aged kidney and their changes after acute renal ischemia are rarely known. The aim of this study was to examine the expression of Ang II receptor mRNA and characteristics of Ang II receptors in the aged kidney and to compare different responsiveness to 45 min of acute renal ischemia in young (3-4 months) and aged (23-24 months) rats. In the normal condition, AT1 mRNA expression was much lower in the aged than that in the young rats. Maximal binding (Bmax) was also lower in the aged (1315 +/- 48 vs. 2035 +/- 257 fmol/mg, p < 0.05). The dissociation constant (KD) of glomerular Ang II receptors, however, was significantly lower in the aged rats compared to the young (6.8 +/- 1.6 vs. 17.4 +/- 2.5 nM). After acute ischemia, the expression of AT1 mRNA decreased in the young rats but increased in the aged rats. Interestingly, Bmax of glomerular Ang II receptors was significantly increased in the aged ischemic rats (1852 +/- 94 vs. 1315 +/- 48 fmol/mg) with unchanged KD. These results show that: (a) the AT1 mRNA expression and the Ang II receptor binding site are decreased with the aging process in the rat kidney; (b) the acute renal ischemia effect on different age groups has a greatly discrepant pattern in respect of Ang II receptor modulation, which may provide a potential therapeutic future for the receptor antagonists in acute renal ischemia in the aged.

[Studies on triterpenoids of total glucosides of tripterygium wilfordii]

Three more triterpenoids were isolated from total glucosides of tripterygium wilfordii (T1). T16 and T17 were identified as salaspermic acid and as wilforlide B. T18 was a new compound. The structure of T18 was determined, as 3-oxo-22 alpha-hydroxy-delta 12-oleanen-29-oic acid by detail spectroscopic and chemical analysis, and named triptotriterpenonic acid A.