The La protein in Schizosaccharomyces pombe: a conserved yet dispensable phosphoprotein that functions in tRNA maturation

Most RNA polymerase III transcripts are bound immediately after synthesis by an abundant nuclear phosphoprotein known as the La autoantigen. Experiments performed in the budding yeast Saccharomyces cerevisiae have revealed that binding of the La protein to tRNA precursors is required for the endonucleolytic maturation of the 3' terminus of many tRNAs. In the absence of this protein, the 3' ends of these tRNAs are trimmed by exonucleases (Yoo CJ, Wolin SL, 1997, Cell 89:393-402). Here we report the characterization of the La protein in the fission yeast Schizosaccharomyces pombe. As was described for budding yeast, S. pombe cells lacking the La protein are viable and exhibit alterations in the pathway of pre-tRNA maturation. Introduction of either the human, S. cerevisiae, or S. pombe La protein into these cells restores the detected pattern of tRNA processing intermediates to that of wild-type cells. By performing immunoprecipitations from cells that were metabolically labeled with 32P-orthophosphate, we demonstrate that the S. pombe and S. cerevisiae La proteins, like the human La protein, are phosphorylated in vivo. Thus, although the La protein is dispensable for growth in these yeasts, both the structure of the protein and its function in pre-tRNA maturation have been highly conserved throughout evolution.

[Molecular biology studies on metalloproteinase and tissue inhibitor of metalloproteinase expression in salivary adenoid cystic carcinoma]

In order to research the relation between metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) and metastasis of salivary adenoid cystic carcinoma (ACC). We use dot blotting to analyse the expression of MMP-2, MMP-9 and TIMP-2 in ACC-2, a cell line of ACC in palate and ACC-M, a high lung metastasis clone which cloned from ACC-2. The result showed the expression of MMP-2 and MMP-9 were higher in ACC-M than that in ACC-2, but the expression of TIMP-2 were higher in ACC-2 than that in ACC-M This suggest MMP-2 and MMP-9 can promote ACC metastasis, TIMP-2 can suppress ACC metastasis. MMP and TIMP maybe a key mechanism of ACC metastasis.

A new method for computerized tomography diagnosis of early transtentorial hernia

OBJECTIVE

To evaluate a new scanning method designed for the diagnosis of early transtentorial hernia as compared with the routine scanning method (parallel to orbitomeatal line).

METHODS

102 patients with unilateral high intracranial pressure and 100 volunteers without any cranial symptoms and signs were scanned on (1) the plane perpendicular to the plane of clivus and (2) the plane parallel to orbitomeatal line, a line joining the apex of the dorsum sellae and the lowest point of the clivus.

RESULTS

Vertical-to-clivus scanning method directly demonstrated the temporal transtentorial hernia in 48 of 102 patients with unilateral high intracranial pressure, but the orbitomeatal line scanning method was not able to show this direct finding. The projected tissue of the temporal lobe could be obviously shown and the degree of the hernia could be judged directly on the CT imaging with the vertical-to-clivus scanning method. Therefore, the CT diagnosis criterion of the hernia was suggested as follows: the hernia would be determined if the downward shift of the temporal lobe was more than 3 mm and suspected if less than 3 mm with ipsilateral high intracranial pressure.

CONCLUSION

This new method presented a superiority in showing the temporal transtentorial hernia for the patients with a cranial emergency.

[Evaluation of different methods of detection and diagnosis for infectious pulmonary tuberculosis]

OBJECTIVE

To evaluate the compare the efficiency and benefit of fluoroscopy and direct sputum examination.

METHOD

The suspected persons with pulmonary tuberculosis symptoms were enrolled to be examined with fluoroscopy, chest radiography, sputum smear and culture.

RESULT

The diagnostic procedure used by World Bank-loaned Tuberculosis Control Project in China is based on fluoroscopy screening. The miss-detection rates of smear positive, culture positive and bacteriological positive pulmonary tuberculosis were 10.5%, 28.3% and 28.2% respectively. Its accuracy of diagnosis was lower than that of direct sputum smear examination and the cost was higher.

CONCLUSION

Direct sputum smear examination seems to be the best diagnostic method for infectious pulmonary tuberculosis and suitable for application in rural areas.

The comparative effects of lansoprazole, omeprazole, and ranitidine in suppressing gastric acid secretion

The effects on 24-hour intragastric pH levels of once-daily doses of lansoprazole 15 mg and lansoprazole 30 mg were compared with the effects of omeprazole 20 mg QD and ranitidine 150 mg QID in a phase I, randomized, double-masked, four-way crossover study conducted in 29 healthy male volunteers. Subjects received each treatment regimen for 5 consecutive days with at least a 2-week washout between treatment periods. Ambulatory 24-hour intragastric pH values were monitored in each subject at baseline (2 days before crossover period 1) and again before dosing on day 5 of each of the four crossover treatment periods. Gastric pH values increased during all four regimens, with significantly higher mean 24-hour pH values noted in subjects receiving lansoprazole 30 mg QD (4.53 +/- 0.16) compared with those receiving lansoprazole 15 mg QD (3.97 +/- 0.16), omeprazole 20 mg QD (4.02 +/- 0.16), or ranitidine 150 mg QID (3.59 +/- 0.16). Lansoprazole 30 mg produced significantly greater mean percentages of time that the gastric pH was above 3.0 and 4.0 (75% and 63%, respectively) compared with the other treatment regimens. The mean percentages of time during which gastric pH was above 3.0 and 4.0, respectively, for the other treatments were lansoprazole 15 mg, 64% and 48%; omeprazole 20 mg, 63% and 51%; and ranitidine 150 mg, 52% and 38%. All treatment regimens were well tolerated, with no clinically significant differences between the regimens. Multiple-dose lansoprazole 30 mg QD produced a significantly increased intragastric pH level and significantly longer durations of increased intragastric pH level compared with lansoprazole 15 mg QD, omeprazole 20 mg QD, and ranitidine 150 mg QID.

Human estrogen receptor-like 1 (ESRL1) gene: genomic organization, chromosomal localization, and promoter characterization

Estrogen receptor-like 1a (ESRL1a; same as estrogen receptor-related orphan receptors, ERR1) belongs to a subfamily of the nuclear receptor superfamily. We have previously shown that human ESRL1a modulates estrogen responsiveness of the lactoferrin gene promoter in transiently transfected endometrial carcinoma RL95-2 cells. In this study, we cloned and characterized the human ESRL1 gene. Through the fluorescence in situ hybridization method, the ESRL1 gene was localized to the centromere region of chromosome 11q12. Partial sequencing, restriction mapping, and PCR analysis revealed that the ESRL1 gene consists of seven exons and is approximately 20 kb in length. We found that the smallest exon (exon 3) contains 117 bp and the largest exon (exon 7) has 1032 bp. The smallest intron (intron 5) is only 88 bp long and the largest intron (intron 2) is 8 kb long. All introns have the conserved GT and AG dinucleotides present at the donor and acceptor sites, respectively. Like the estrogen receptor, the highly conserved DNA-binding domain of hESRL1a is encoded by exon 2 and exon 3, and the intron/exon junctions (2 and 3) are well conserved between the two genes. Primer extension analysis revealed multiple transcription initiation start sites in human uterine (HeLa, HEC, and RL95-2) cell lines. However, one major initiation start site was found by RNase protection assay. The hESRL1a mRNA is differentially expressed in various human tissues. The nucleotide sequence adjacent to the transcription start sites of the ESRL1 lacks the typical TATA and CAAT boxes but is GC rich and contains 10 consensus Sp1-binding elements and two E boxes. The region that contains these transcription factor-binding elements showed a high level of promoter activity when transiently transfected into RL95-2 cells.

Identification of two novel and four uncommon missense mutations among chinese Gaucher disease patients

Gaucher disease is the most prevalent lysosomal storage disease. It is panethnic and results from an inherited deficiency of glucocerebrosidase. Most mutations to date have been identified among Jewish and non-Jewish Caucasian patients; mutations in Chinese patients are largely unknown. We have performed nucleotide sequence analysis of PCR-amplified glucocerebrosidase genomic DNA from five unrelated Chinese patients affected with type 1 (non-neuropathic) Gaucher disease. A novel heterozygous C --> T mutation at cDNA nucleotide position 475 (R120W) was detected in a patient who is also heterozygous for a C --> T transition at cDNA nucleotide position 259 (R48W). In a second patient, a novel, heterozygous T --> G transversion at cDNA 226 (F37V) was detected. Mutation 1448 (L444P), the most prevalent mutation among non-Jewish Caucasian Gaucher patients, was found in the heterozygous form in four patients. The mutations in the second Gaucher allele in the other three patients are mutations 254 (G46E), 680 (N188S), and 754 (F213I), which were recently reported in Korean, Arab, and Chinese (Taiwanese) patients. We have developed screening methods that utilize PCR amplification of glucocerebrosidase genomic DNA and Eco571, Nci1, Hinc11, BsaJ1, and Bsr1 restriction endonuclease analyses for the detection of each of these mutations. The population genetics of some of these Gaucher alleles and their implications in genotype/phenotype correlation are discussed.

[Oxygen free radical on interleukin-1 activity of hemorrhage/resuscitation rat]

OBJECTIVE

To investigate the effects of oxygen free radical on the enhancement of IL-1 activity in vivo and in vitro on hemorrhagic and resuscitated rat.

METHODS

30% of rats total blood volume was withdraw by carotid artery catheter and resuscitated with 2 times of lost blood volume 1 h later.

RESULTS

Plasm IL-1 activity and MDA content increased and SOD activity decreased significantly 1-4 hours after resuscitation. There was a marked correlation between IL-1 activity and MDA content as well as SOD activity. Treatment with SOD as resuscitation prevented the postresuscitation increase in plasma IL-1 activity significantly. Hemorrhage and resuscitation also caused significant decrease of SOD activity and elevation of MDA in peritoneal macrophage 2 hours after resuscitation. After preincubation with SOD for 1 hour, the macrophage presented a much lowered capacity to release IL-1.

CONCLUSION

Oxygen free radical may be one of the most important factors that contribute to elevation of IL-1 level after hemorrhage and resucitation.

[Role of type IV collagene and type IV collagenase in the invasion and metastasis of salivary adenoid cystic carcinoma]

Using immunohistochemical ABC method, the authors studied the distribution of type IV collagen and type IV collagenase in 25 cases ACC. The result showed type IV collagen was found in vascular and epithelial basement membrance, and in partly cyst of sieve-like and tubular pattern, and in cytoplasm of tumor cell. Type IV collagenase was detected in membrance and cytoplasm of tumor cell. Expression of type IV collagen and type IV collagenase were correlated with pathologic type, TNM stage and metastasis. Much positive staining of type IV collagen was found in sieve-tubular pattern, early stage of TNM and without metastasis, but much positive staining of type IV collagenase was found in solid pattern, later stage of TNM and metastasis. The result suggested that the loss of type IV collagen and over-expression of type IV collagenase may be markers of malignance of ACC.

Effects of anoxia, acidosis and temperature on the contractile properties of turtle cardiac muscle strips

The responses to anoxia and acidosis of cardiac ventricular muscle strips from the anoxia-tolerant turtle Chrysemys picta bellii were investigated at 10 degrees C and 20 degrees C. Force-velocity curves were determined by quick isotonic releases at 85% of the time to peak isometric force under control, anoxia, lactate acidosis and anoxic lactate acidosis conditions. The isotonic forces during quick releases spanned 5-95% of the measured isometric force at each conditions. Superfusion solution pH was 7.8 and 7.95 for non-acidosis experiments, and 7.0 and 7.15 for acidosis experiments, at 20 degrees C and 10 degrees C, respectively. After normalizing force data to control isometric force, the values of maximum isometric force (P0), maximum velocity of shortening (Vmax) and maximal power output (Powermax) were evaluated by fitting the curves using the hyperbolic Hill equation. The maximum rate of force development (dF/dtmax), time-to-peak force (TPF) and half-relaxation time (T1/2) were also determined. At 20 degrees C, during acidosis, anoxia and anoxic acidosis, P0 decreased significantly to 81%, 40% and 24% of control values, dF/dtmax decreased significantly to 67%, 53% and 23% of control values, and Powermax decreased significantly to 75%, 40% and 14% of control values, respectively. Vmax, however, was not significantly affected by acidosis, anoxia or even anoxia acidosis. TPF was significantly shortened by anoxia, but prolonged by acidosis. The effects were similar at 10 degrees C, Temperature did not affect P0, but Vmax decreased by a factor of 1.6-1.8 at all corresponding conditions when temperature was reduced from 20 degrees C to 10 degrees C. We conclude that acidosis and anoxia inhibit isometric force production and Powermax of turtle cardiac muscle, but have no effect on Vmax, and the insensitivity of Vmax indicates that the rate of cross-bridge cycling is not affected by these conditions. Our observations indicate that the reduced power outputs of the hearts of submerged anoxic turtles at low temperature are due in part to inhibition of force production by anoxia and acidosis, and to a reduction of contraction velocity at low temperature.

[CT examination and diagnosis of oral and maxillofacial tumors invading the pterygopalatine space]

CT findings in 33 cases (proven histopathologically) suffered from oral and maxillofacial tumors affecting the pterygopalatine space were retrospectively analyzed. The authors conclude that the main CT manifestations of this space involvement by tumors can be depicted as a soft tissue mass occupancy and the wall structures destruction. Tumors occurring in different locations of oral and maxillofacial areas have different features of CT appearances. In addition, the primary tumor of this space is probed from histogenesis and CT findings, and its diagnostic criteria are discussed. As a modality of imaging, CT has an important role for assessing the lesions of this fossa.

[Comparison of anti-hepatitis C virus (HCV) IgM and HCV-RNA detection in serum samples of patients with HCV infection]

Anti-HCV IgG is the routine assay for the diagnosis hepatitis C. But the method is ineffective in early detection of hepatitis C. We have detected anti-HCV IgM in hospital hepatitis C patients by Enzyme-Linked Immunosorbent Assay (ELISA) and compared the results with those of HCV-RNA and total antibody. Our studies indicate that anti-HCV IgM is detected in all hepatitis C marker positive sera. But the amount of anti-HCV IgM in HCV-RNA positive sera is significantly higher than that of in the corresponding negative sera. This subjects that anti-HCV IgM and HCV-RNA are somewhat correlated and they have different clinical interests. Anti-HCV IgM can be expected and hepatitis activities and its actual clinical interests are to be further studied.

Promoter and species specific differential estrogen-mediated gene transcription in the uterus and cultured cells using structurally altered agonists

Certain types of estrogenic compounds have been shown to have tissue-specific actions. In addition, some tissues may exhibit differential gene regulation by agonists and antagonists. Our previous studies using structurally modified estrogenic molecules had indicated differential effects on specific estrogen responses, indicating that the activity of the estrogen receptor protein can be altered depending not only upon the structure of the bound ligand but also the regulated gene itself. The mechanism of differential induction, however, was not determined, and might involve altered binding to the estrogen response element (ERE), altered transcription, or post-transcriptional modification of gene products. Our previous studies indicated that differential induction by modified diethylstilbestrol (DES) agonists could not be accounted for by differences in ligand affinity for the estrogen receptor (ER) or differential binding of the ER to a consensus vitellogenin A2 (vit A2) ERE. To determine if this differential hormonal responsiveness was reflected at the level of transcription, we analyzed mouse uterine mRNA of several estrogen-responsive genes, including glucose-6-phosphate dehydrogenase (G6PD), ornithine decarboxylase (ODC) and lactoferrin, by Northern blot following injection with the modified agonists DES, indenestrol A (IA), indenestrol B (IB) and Z-pseudo DES (ZPD). All compounds induced the G6PD message, although IB and ZPD induced expression only transiently, while DES and IA maintained the message for 24 h. No difference in induction was seen for ODC message, which was induced equally by all the compounds. In contrast, lactoferrin, a highly estrogen-responsive gene, was induced only by DES and IA and not by the other agonists IB or ZPD, showing that the lactoferrin gene was differentially regulated by these compounds. To determine whether this difference was due to altered transcriptional activity, the mouse lactoferrin estrogen-responsive module (mERM) linked to a chloramphenicol acetyl transferase (CAT) reporter gene was tested in transfected cells. Using the mouse estrogen receptor in RL95 cells, DES and IA induced expression of CAT, but IB did not, confirming the differential response seen in vivo. To show whether this difference in transcription occurred because of altered binding to the lactoferrin ERE, which is not a perfect consensus ERE a gel shift assay was used to examine DNA binding of ER bound to the agonists. All ligands produced equivalent binding to the lactoferrin ERE suggesting that differential regulation was not a result of altered DNA binding. Taken together, these observations indicate that the differential induction of lactoferrin by these compounds occurs via altered activation of the transcriptional components unique to lactoferrin and is likely to involve altered interaction with co-activators. Surprisingly, unlike the mouse ER, the human estrogen receptor activated and induced expression of lactoferrin estrogen-responsive module-CAT with all the compounds. Mouse ER is also known to vary from the human ER in its activity with the triphenylethylene estrogen tamoxifen, which has agonist activity with the mouse ER but mixed antagonist/agonist activity with the human ER. The data show that human and mouse estrogen receptors are activated differently by this group of stilbestrol estrogen ligands when assayed on the lactoferrin response element, which is the first description of this type of gene and species specific difference. Lactoferrin gene regulation by estrogen receptor can be used as a model to study the mechanism of differential gene activation by different estrogen agonists and antagonists using a more physiological situation than commonly used with in vitro gene reporter systems.

Children's thinking in the wake of Challenger

OBJECTIVE

The Challenger spacecraft explosion in 1986 offered an opportunity to study the thinking of normal children after a sudden and distant disaster, differences in thinking among children of different levels of emotional concern and different ages, and changes in their thinking over time.

METHOD

The authors studied six thinking patterns known to characterize childhood posttraumatic stress disorder and four additional hypothesized patterns in 153 randomly selected children of Concord, N.H. (who watched the explosion on television) and Porterville, Calif. (who heard about it later). They compared the structured-interview responses of the more involved (East Coast) and less involved (West Coast) children, of the latency-age children and the adolescents, and of the children initially (5-7 weeks after the explosion) and 14 months later.

RESULTS

The children exhibited the 10 predictable thinking patterns. They initially defended themselves, denying the reality of the explosion. They later fantasized about it. They tried to cope by seeking additional information on their own, at home, and at school. Most children talked about Challenger, but a minority of the latency-age youngsters avoided related talk and thoughts. The adolescents experienced more paranormal thinking, philosophical changes, and negative attitudes. Over the year, omens, paranormal experiences, and Challenger-based fantasies tended to disappear, but negative views about institutions and the world's future held steady or increased.

CONCLUSIONS

The children's thinking followed predictable patterns. A higher degree of emotional involvement (East Coast children) was strongly linked to these thinking patterns, as was being an adolescent. Distant disasters appear to set up commonalities of thought that might come to characterize certain generations of children.

Identifying hospitalized older patients at varying risk for physical performance decline: a new approach

OBJECTIVE

A classification tree analysis identifies patient groups at varying risk for decline in physical performance 1 year after hospitalization.

DESIGN

Prospective cohort study.

SETTING

Tertiary care VAMC.

PARTICIPANTS

A total of 507 acutely ill hospitalized male veterans aged 65 years and older.

MEASUREMENTS

Eighteen admission characteristics were considered as potential predictors: demographic data, medical diagnoses, functional status (e.g., ADL and IADL), geriatric conditions (e.g., incontinence, vision impairment, weight change), mental status, depression, and physical functioning (measured by self-report (MOS-PFR) and the Physical Performance and Mobility Examination (PPME)). Outcome measure was change in PPME status at 12-months post-admission.

RESULTS

Patients with the greatest risk for decline had both high baseline physical performance (PPME > or = 9) and at least moderate self-report limitations on physical functioning (MOS-PFR < or = 36, mean = 30.8). Patients with the lowest risk of decline had impaired baseline physical performance (PPME < or = 8) but fewer self-report limitations on physical functioning (MOS-PFR > or = 31, mean = 37.4) and two or less geriatric conditions.

CONCLUSIONS

The predictive role of self-report functioning suggests that perception of the impact of health on one's own physical functioning is associated with future performance. The number of geriatric conditions is also an important predictor of physical performance change. By identifying patient risk groups based on geriatric conditions, physical performance, and self-report physical functioning, future targeting strategies may improve physical performance outcomes for hospitalized older adults.

Associations between cytochrome P4502E1 genotype, mutagen sensitivity, cigarette smoking and susceptibility to lung cancer

Cytochrome P4502E1 (CYP2E1) is involved in the metabolic activation of carcinogenic N-nitrosoamines. We therefore assessed the genotype frequencies of PstI or RsaI CYP2E1 restriction fragment length polymorphisms and another susceptibility marker, mutagen sensitivity, in 137 lung cancer cases (92 African American and 45 Mexican American) and 206 controls (114 African American and 92 Mexican American) identified in a molecular epidemiological study of lung cancer. The CYP2E1 c1/c1 genotype was found in 86.7% of Mexican American cases, 70.6% of Mexican American controls, 89.1% of African American cases and 86.8% of African American controls. By multivariate analysis, this genotype was found to be associated with a 14.0-fold increased risk of lung cancer in Mexican Americans but not in African Americans; a 9.9-fold increased risk of lung cancer in Mexican American former smokers, but not in non-smokers or current smokers; a 15-fold increased risk of lung cancer in Mexican American males, but not in females. Patients with the susceptible genotype appeared to have developed cancer at an earlier age and with lower cigarette pack-year of exposure than did patients with the c1/c2 or c2/c2 genotypes. Stratified analysis suggested a greater than multiplicative interaction between cigarette smoking and CYP2E1 c1/c1 genotype, although not statistically significant. The odds ratios (ORs) for the CYP2E1 c1/c1 genotype, cigarette smoking and both risk factors combined were 1.3, 6.7 and 16.3, respectively. The association between CYP2E1 c1/c1 genotype and pack-years of smoking followed the same pattern. The interaction between mutagen sensitivity and CYP2E1 c1/c1 genotype was especially strong in former smokers (the ORs for the CYP2E1 c1/c1 genotype, mutagen sensitivity and both risk factors combined were 3.9, 5.4 and 23.0, respectively). Therefore, the data suggest that individuals who lack a c2 allele might be at higher risk for developing lung cancer.

A specific RNA hairpin loop structure binds the RNA recognition motifs of the Drosophila SR protein B52

B52, also known as SRp55, is a member of the Drosophila melanogaster SR protein family, a group of nuclear proteins that are both essential splicing factors and specific splicing regulators. Like most SR proteins, B52 contains two RNA recognition motifs in the N terminus and a C-terminal domain rich in serine-arginine dipeptide repeats. Since B52 is an essential protein and is expected to play a role in splicing a subset of Drosophila pre-mRNAs, its function is likely to be mediated by specific interactions with RNA. To investigate the RNA-binding specificity of B52, we isolated B52-binding RNAs by selection and amplification from a pool of random RNA sequences by using full-length B52 protein as the target. These RNAs contained a conserved consensus motif that constitutes the core of a secondary structural element predicted by energy minimization. Deletion and substitution mutations defined the B52-binding site on these RNAs as a hairpin loop structure covering about 20 nucleotides, which was confirmed by structure-specific enzymatic probing. Finally, we demonstrated that both RNA recognition motifs of B52 are required for RNA binding, while the RS domain is not involved in this interaction.

[Effect of sodium iron chlorophyllin (SIC) on CFU-E and CFU-GM yields of normal and anemic animal models]

OBJECTIVE

To observe the effect of sodium iron chlorophyllin (SIC) on hematopoiesis and its therapeutic efficacy in anemic mice.

METHODS

The effects of SIC on CFU-E and CFU-GM yields of normal and anemic animal models were studied.

RESULTS AND CONCLUSIONS

(1) SIC significantly enhanced the CFU-E and CFU-GM yields of mouse bone marrow. (2) SIC also increased the percentage of reticulocyte in mouse. (3) In hemolytic anemia mice induced by i.p. N-acetphenylhydrazine, SIC markedly prevented the decrease of RBC and Hb. (4) In hemorrhagic anemia rats induced by bleedletting, SIC accelerated the normalization of RBC, Hb and elevated the serum iron level and transferrin saturation.

[A study on the possible mechanism for the second control site of insulin secretion in islets]

Glucose stimulation of insulin release involves closure of ATP-sensitive K+ channels (K(+)-ATP channels) in beta cells. However, by using diazoxide to open K(+)-ATP channels, it has been reported that another mechanism exists, by which glucose can control insulin release independently from changes in K(+)-ATP channel activity. These data suggested that there is a second control site in islets when insulin is secreted. To probe the possible existence of this site, mouse islets were used to investigate the energy state of islets in insulin secretion when the activity of K(+)-ATP channels was eliminated by diazoxide. In the present study, isolated islets were cultured in PRMI 1640 medium for 18 hours. The islets were then divided into 6 groups randomly, with 10 islets per group, placed in 1 ml KREBS medium containing 30 mmol/L K(+) and 250 mmol/L diazoxide with 0, 3, 6, 10, 15, 20 mmol/L glucose respectively and incubated in 37 degrees C water for 60 minutes. A portion of the supernatant was withdrawn at the end of the incubation for insulin assay, the islets were treated with trichloracetic acid and diethyl ether for the measurements of ATP, ADP, GTP and UTP. The above findings demonstrated that insulin secretion increases with the rise of glucose concentration. In the same time, the level of ATP increaseded and the level of ADP decreased gradully. The ratio of ATP/ADP in islets correlated with the insulin secretion very well. The level of GTP and UTP also increased with the rise of glucose concentration. It is suggested that glucose can control insulin secretion independently from its action of K(+)-ATP channels and the existence of a second control site as an another mechanism for insulin release. The ratio of ATP/ADP is an important factor in this mechanism; GTP and UTP also participated in the control of insulin secretion.

Infiltration of eosinophils into the asthmatic airways caused by interleukin 5

Interleukin (IL)-5 is thought to play an important role in asthmatic bronchial mucosal inflammation and is a potential therapeutic target. To investigate the effect of IL-5 on the infiltration of eosinophils in airway in vivo, we compared eosinophil counts and their activation status in airways without and after the topical instillation of recombinant human IL-5. Eight subjects with mild atopic asthma underwent initial bronchoscopy during which control bronchoalveolar lavage (BAL) fluid as well as bronchial mucosa were obtained, and at the same time, normal saline and IL-5 were administered to two sublobar segments separately. The second bronchoscopy were carried out and samples from challenged sites were taken 24 h later. It was found that the total eosinophils (BMK-13+ cells) and the activated eosinophils (EG2+ cells) in bronchial mucosa, the eosinophil numbers in BAL fluid, as well as eosinophil cationic protein (ECP) in BAL fluid from saline-challenged segments were not different from those in unchallenged segments. However, a significant eosinophilia was observed in bronchial mucosa and BAL fluid from IL-5-challenged sites. Eosinophil activation, as assessed by secretion of ECP, was also increased significantly in bronchial mucosa and BAL fluid. The results strongly suggested that IL-5 is capable of inducing eosinophil infiltration into the asthmatic airways, as well as the activation of infiltrating eosinophils.

[In vitro reversal of homoharringtonine resistance by the combination of tamoxifen and verapamil]

OBJECTIVE

To investigate the reversal of homoharringtonine (HHT)-resistance by tamoxifen (TAM) or verapamil (VER) alone or in combination.

METHODS

The drug-sensitivity test was performed with semisolid agar culture.

RESULTS

The cytotoxicity of HHT to K562/S cells was not enhanced by TAM or VER alone or in combination,but HHT resistance in HHT resistant cells (K562/H20) was reversed by VER and TAM at nontoxic doses (4micromol/L or 8micromol/L). The IC50 of K562/H20 for HHT decreased from 446.8 +/- 0.08microg/L to 45.1 +/- 0.02microg/L in the presence of 4micromol/L of VER, to 22.4 +/- 0.03microg/L in 8micromol/L of VER, to 85.1 +/- 0.03microg/L in 4micromol/L of TAM and to 26.4 +/- 0.02microg/L in 8micromol/L of TAM. In the presence of combinations of 2micromol/L VER and 4micromol/L TAM and of 2micromol/L VER and 8micromol/L TAM, IC50 of K562/H20 decreased to 30.4 +/- 0.02microg/L and 4.3 +/- 0.04microg/L, respectively.

CONCLUSION

HHT-resistance could be reversed by VER or TAM alone, and the combination of the two drugs showed a synergistic effect.

[Preliminary study on differentiation of syndromes during HDT -6 degrees bed rest with traditional chinese medicine]

Differentiation of syndromes during 21 d HDT -6 degrees bed rest was made in 15 healthy young men. The results indicated that the subjects showed mainly deficiency of kidney-Yin, deficiency of Yin and hyperactivity of Yang, insufficiency of spleen-Qi and blood stasis in various degrees during the bed rest. The syndromes were most serious on the 3rd day, and then deficiency of kidney and deficiency of Yin and hyperactivity of Yang became mild gradually but insufficiency of spleen-Qi and blood stasis remained the same. The pulse condition was normal through the bed rest period

[nm23 expression and its correlation with lung metastasis in human salivary adenoid cystic carcinoma]

The nm23 gene products, nucleoside diphosphate kinase (NDPK), expression in salivary adenoid cystic carcinoma (ACC) was evaluted by using LSAB immunohistochemical method. Of 25 cases tested, 16 (64.0%) showed positive staining, in which, higher incidence of positive staining was found in ACC without lung metastasis (88.2%, 15/17) than in that with lung metastasis (12.5%, 1/8; P < 0.01). Expression of NDPK/nm23 was correlated with the P-TNM pattern (P < 0.05), otherwise it was not correlated with pathologic types (P > 0.05). The result suggest that the nm23/NDPK may play a role in suppressing the metastatic potential in ACC.

Mechanisms of pHi recovery from NH4Cl-induced acidosis in anoxic isolated turtle heart: a 31P-NMR study

Mechanisms of intracellular pH (pHi) recovery from NH4Cl-induced acidosis were investigated on isolated perfused hearts of the turtle, Chrysemys picta bellii, using 31P nuclear magnetic resonance (NMR) spectroscopy at 20 degrees C. A major goal was to assess the activity of these mechanisms under anoxic conditions. Based on calculated buffer capacity and a pHi recovery range at 20 degrees C of 6.75-6.95 (normal pHi 7.2-7.4), mean H' efflux rate during perfusion with CO2-free N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES)-buffered Ringer was only 15% (normoxia) and 25% (anoxia) of that with HCO3-buffered Ringer. With HCO3 solution, anoxic H1 efflux rate was approximately 50% of normoxia (0.333 vs. 0.645 mmol.l-1.min-1), but in TES solution, H1 efflux rate was unaffected by anoxia. To further characterize the transporters, we used blockers [the Na(+)-H+ antiport inhibitor 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) and the anion exchanger inhibitor 4,4'diisothiocyanostilbene-2, 2'-disulfonic acid (DIDS)], ion substitution, and temperature change. EIPA (10 microM) inhibited H+ efflux rate by 40% in anoxic TES solution; DIDS (0.5 mM) blocked H+ efflux rate by 85% in anoxic HCO3 solution. No pHi recovery was observed in either normoxic or anoxic Na(+)-free solutions, but normal recovery was observed in the absence of extracellular Cl-. Recovery of pHi occurred 2-3 times faster at 30 degrees C than at 20 degrees C. ATP was unaffected by any manipulation in this study, whereas creatine phosphate (CP) fell during anoxia, and both CP and mechanical performance changed in parallel to pHi. We conclude that pHi regulation functions during anoxia, although at a reduced rate, and that recovery from acidosis is dominated, during both normoxia and anoxia, by a DIDS-sensitive Na+ and HCO3(-)-dependent mechanism, whereas EIPA-sensitive Na(+)-H+ antiport plays a less important role.

Antioxidant property of Fructus Momordicae extract

The antioxidant effect of Fructus Momordicae extract, FME (mogrosides 75 approximately 80%), was studied. FME reduced the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and scavenged superoxide radicals (O2-) generated by a hypoxanthine and xanthine oxidase system. It also scavenged hydroxyl radicals (.OH) generated by Fenton reaction. In addition, FME inhibited Fe(II) induced lipid peroxidation in rat cortex homogenates in a dose-dependent manner, as indicated by decreased thiobarbituric acid-reactive substances (TBARS) formation. Oral administration of FME inhibited TBARS and malonaldehyde (MDA) formation in the ipsilateral cortex 30 min after iron-salt injection into the left cortex of rat. FME showed inhibitory effect on 4-hydroxy-2(E)-nonenal (4-HNE) formation induced by Fe(III) injection into the rat cortex. These data suggest that Fructus Momordicae extract has an antioxidant activity against free radicals and lipid peroxidation.

[Differentiation of cytology of BALF between BOOP and UIP]

OBJECTIVE

BOOP is a disease entity proposed by Epler in 1985, and UIP is considered an important disease to be differentiated from BOOP. The aim of this study was to identify characteristic features in BALF samples of patients with BOOP and UIP.

METHODS

Differential cell count and T-cell subpopulation of the BALF obtained from 7 patients with BOOP and 7 patients with UIP, both histologically verified, were determined.

RESULTS

In BOOP patients the ratio of lymphocytes and the CD8+ cell in BALF were significantly higher and CD4+/cd8+ ratio was significantly lower than those of the UIP patients (P < 0.01). In UIP patients the ratio of neutrophils in BALF was significantly higher than that of the BOOP patients (P < 0.05).

CONCLUSIONS

Cytological examination of BALF is effective in differentiating BOOP from UIP and it can provide useful information about both different pathogenetic processes of the two entities.

Analysis of Chinese isolates of Trichinella spiralis by molecular biotechnology

OBJECTIVE

To investigate the relationships among Trichinella spiralis isolates obtained from different hosts and geographical regions in China.

MATERIALS AND METHODS

Six isolates of Trichinella spiralis obtained from Changchun, Tianjin, Xi'an, Henan and Yunnan were detected. All the isolates were collected from pigs or dogs. Restriction fragment length polymorphism (RFLP), isoenzyme electrophoresis and soluble protein analysis were used.

RESULTS

Distinctive banding patterns in restriction maps were seen between Changchun and other isolates studied. A cloned specific repetitive DNA sequence (1.12 kb) from Changchun isolate was then selected to prepare probe for Southern blotting of DNA fragments. The hybridizing banding patterns among the isolates were different and only the Changchun isolate showed the 1.12 kb band. The Changchun isolate was also distinguishable from the other isolates in isoenzyme patterns of GP1, G6PD, HK, 6PGDH and AK, as well as in isoelectric focusing electrophoresis where the Changchun isolate presented a specific band at 4.1 P1.

CONCLUSIONS

There are at least two different biological types of Trichinella spiralis in China and the differences between them may be attributed to different geographical origins and/or different hosts.

Gastrointestinal tract complications of nonsteroidal anti-inflammatory drug treatment in rheumatoid arthritis. A prospective observational cohort study

BACKGROUND

Gastrointestinal tract (GI) complications associated with nonsteroidal anti-inflammatory drug (NSAID) use are the most common serious adverse drug reactions in the United States. Nonsteroidal anti-inflammatory drugs cause both minor GI side effects such as abdominal pain and vomiting and serious GI events such as ulcers and bleeding. This study evaluates the event rates for all NSAID-induced GI complications in patients with rheumatoid arthritis, describes the time course of these events, and evaluates the role of prophylactic therapy with antacids and H2 receptor antagonists.

METHODS

We studied 1921 patients with rheumatoid arthritis from 8 ARAMIS (Arthritis, Rheumatism, and Aging Medical Information System) centers. Patients were selected for the study if they were treated with NSAIDs and had at least 2.5 years of observation available. Information on GI complications attributed to NSAIDs was obtained from validated patient self-reports collected every 6 months and supplemented by review of hospital records for all hospitalizations.

RESULTS

Approximately 15% of the 1921 patients reported an NSAID-induced GI side effect during the 2.5 year observation period. Forty-two patients had a serious GI complication requiring hospitalization; 34 of these 42 patients did not have a preceding GI side effect. Patients who were taking antacids and H2 receptor antagonists did not have a significantly lower risk for serious GI complications than did those not taking such medications. Asymptomatic patients taking these medications had a significantly higher risk for GI complications compared with those who did not take these medications (standardized odds ratio, 2.14;95% confidence interval, 1.06-4.32).

CONCLUSIONS

A large majority of patients with serious GI complications do not have preceding mild side effects. Prophylactic treatment with antacids and H2 receptor antagonists is of questionable value and may increase the risk for subsequent serious GI complications.

A misfolded form of 5S rRNA is complexed with the Ro and La autoantigens

In both vertebrate and invertebrate cells, the 60-kDa Ro autoantigen is bound to small cytoplasmic RNAs known as Y RNAs. In Xenopus oocytes, the 60-kDa Ro protein is also complexed with a class of 5S rRNA precursors that contain internal mutations. Because these 5S rRNA precursors are processed inefficiently and degraded eventually, the Ro protein may function in a quality control pathway for 5S rRNA biosynthesis. We have investigated the sequence and secondary structure determinants in the mutant 5S rRNAs that confer binding by the 60-kDa Ro protein. The mutant 5S rRNAs fold to form an alternative helix that is required for recognition by the 60-kDa Ro protein. Mutations that disrupt the alternative helix eliminate Ro protein binding, whereas compensatory changes that restore the helix are bound efficiently by the Ro protein. When the structure of the mutant RNA was probed using dimethylsulfate and oligonucleotide-directed RNase H cleavage, the results were consistent with the formation of the alternative structure. The La protein, which is also complexed with the mutant 5S rRNA precursors, protects similar sequences from nuclease digestion as does the 60-kDa Ro protein. Thus, the binding sites for these two proteins are either nearby on the RNA, or the two proteins may be complexed through protein-protein interactions. When the human Ro protein is expressed in the yeast Saccharomyces cerevisiae, the protein binds wild-type 5S rRNA precursors, suggesting that a population of wild-type precursors also folds into the alternative structure.

Effects of divalproex sodium on amitriptyline and nortriptyline pharmacokinetics

BACKGROUND

Divalproex sodium has been found to be efficacious in the prophylaxis of migraine headaches and the management of the manic phase of bipolar syndrome. Because amitriptyline is also prescribed in these patient populations, data are needed on their potential for interaction.

METHODS

The effect of concomitant administration of divalproex sodium on the pharmacokinetics of amitriptyline and its active metabolite, nortriptyline, was investigated in an open-label, sequential, two-period phase I study. Ten healthy male and five healthy female subjects received 50 mg amitriptyline hydrochloride on two occasions: (1) alone (period 1) and (2) 2 hours after receiving the ninth dose of 500 mg divalproex sodium (Depakote) administered once every 12 hours (period 2).

RESULTS

Amitriptyline area under the curve was increased 31% from the combined effect of decreased first-pass metabolism and inhibition of systemic metabolism. The elevated nortriptyline plasma levels reflected primarily the increase in amitriptyline concentrations but also appeared to involve modest inhibition of nortriptyline elimination. For the sum of amitriptyline and nortriptyline concentrations, the peak plasma concentration mean was 19% higher with concomitant divalproex dosing. The mean area under the curve for the sum of amitriptyline and nortriptyline concentrations was 42% higher with concomitant divalproex dosing than it was for dosing with amitriptyline alone.

CONCLUSION

These results suggested that a lower dose of amitriptyline might be considered when divalproex is administered concomitantly.

Promoter-specific activation of mouse lactoferrin gene by epidermal growth factor involves two adjacent regulatory elements

The mouse lactoferrin gene responded to forskolin, 12-O-tetradecanoyl phorbol-13-acetate, and epidermal growth factor (EGF) stimulation via two adjacent enhancer elements, the cAMP response element (CRE) and EGF response element (EGFRE), collectively referred to as the mitogen response unit. In this report, we examined the minimal promoter and enhancer elements of the mouse lactoferrin gene that are required for EGF-induced transcriptional activation. We found that the CRE and noncanonical TATA box (ATAAA) are the minimal promoter elements for basal activity of the chloramphenicol acetyltransferase (CAT) reporter construct whereas the EGFRE is needed for an additional activity induced by EGF in transiently transfected human endometrial carcinoma RL95-2 cells (RL95-2). The EGFRE, however, did not function in heterologous promoters [SV 40 and thymidine kinase (TK)]. Therefore, EGF-stimulated lactoferrin gene activity is promoter specific in RL95-2 cells. In transiently transfected cells, EGF and forskolin showed synergistic effects on the CAT reporter that contained both response elements. Mutation made at either element or insertion of extra nucleotides between the two elements severely affected EGF-stimulated activity. Nuclear protein prepared from RL95-2 cells formed three complexes (A, B, and C) with the oligonucleotides containing both EGFRE and CRE in electrophoretic mobility shift assay. A new complex (E) was detected with the nuclear protein of EGF-treated cells. By oligonucleotide competition experiments, we demonstrated that the complex E was generated by protein bound to CRE. EGF-induced binding activity could be abolished by calf intestinal alkaline phosphatase but not by the protein synthesis inhibitor, cycloheximide. Therefore, binding of a preexisting phosphoprotein to the CRE region could be one of the requirements for EGF-induced mouse lactoferrin gene promoter activity.

[Effect of interferon-gamma on antigen-induced eosinophil infiltration in mouse airway]

Repeated aerosolized ovalbumin (OVA) challenge of OVA-sensitized mice induces bronchoalveolar lavage fluid (BALF) eosinophilia. The influence of interferon-gamma (IFN-gamma) on antigen-induced eosinophil recruitment in the airway as well as the concentration of interleukin-5 (IL-5) in supernatants of cultured spleen cells were examined. In sensitized mice challenged with OVA 20 minutes once a day for 6 days, the number of BALF eosinophils was (9.53 +/- 0.84) x 10(8)/L. However, no eosinophil could be found in the BALF from mice without OVA sensitization and challenge. In mice treated with intraperitoneal injection of INF-gamma before each challenge, different doses of IFN-gamma (1.0 x 10(3) U/kg, 1.0 x 10(4) U/kg and 1.0 x 10(5) U/kg) produced different degrees of eosinophilia inhibition 29.8% (P < 0.05), 55.7% (P < 0.01) and 69.0% (P < 0.01). Our results showed that IFN-gamma prevented antigen-induced eosinophil infiltration in airway accompanied by a decrement of levels of IL-5 with a dose related response. It is concluded that IFN-gamma is capable of inhibiting eosinophil infiltration in mouse airway by inhibiting the production of IL-5. Our results suggested that IFN-gamma may be of value in eliminating asthmatic airway inflammation in humans.

Children's memories in the wake of Challenger

OBJECTIVE

The Challenger spacecraft explosion of Jan. 28, 1986, offered an opportunity to study the memories of normal latency and adolescent children of different emotional involvements following one sudden and distant disaster. How would children of various levels of concern express their memories? And if studied over time, how would these narratives change? Would there be developmental differences? And would there be false details of memory?

METHOD

The authors set out to compare the memories of 153 children from Concord, N.H. (who watched the explosion on television), and Porterville, Calif. (who heard about it). The structured-interview responses of involved and less involved children; latency-age versus adolescent children; and those seen initially (5-7 weeks after the explosion) versus those same children seen later (at 14 months) were statistically compared.

RESULTS

The vast majority of children's memories of Challenger were clear, consistent, and detailed, with highlighting of personal placement, who else was there, and personal occurrences linked to the event. Those children who were less emotionally involved demonstrated significantly less clarity, consistency, and correct ordering of sequences and were less likely to remember personal placement, other people who were there, and related personal incidents. About 30% of all children in this study misunderstood something about Challenger and incorporated these misunderstandings into their memories as false details. Latency-age children continued to harbor false details for 14 months, as opposed to the adolescents.

CONCLUSIONS

Childhood memories of the Challenger space shuttle explosion appeared predictable, were related to patterns of memory that have been observed following single, unrepeated traumas, and reflected age and stage differences.

Estrogen-related receptor, hERR1, modulates estrogen receptor-mediated response of human lactoferrin gene promoter

We have shown previously that estrogen-stimulated transcription from the human lactoferrin gene in RL95-2 endometrium carcinoma cells is mediated through an imperfect estrogen response element (ERE) at the 5 -flanking region of the gene. Upstream from the ERE, a DNA sequence (-418 to -378, FP1) was selectively protected from DNase I digestion by nuclear extracts from endometrial and mammary gland cell lines. In this report, using the electrophoresis mobility shift assay, site-directed mutagenesis, and DNA methylation interference analyses, we show that three different nuclear proteins bind to the FP1 region (C1, C2, and C3 sites). The nuclear receptor, COUP-TF, binds to the C2 site. Mutations in the C1 binding region abolish C1 complex formation and reduce estrogen-dependent transcription from the lactoferrin ERE. When the imperfect ERE of the lactoferrin gene is converted to a perfect palindromic structure, the enhancing effect of the C1 binding element for estrogen responsiveness was abolished. We isolated a complementary DNA (cDNA) clone from an RL95-2 expression library that encodes the C1 site-binding protein. The encoded polypeptide maintains 99% amino acid identity with the previously described orphan nuclear receptor hERR1. A 2.2-kilobase mRNA was detected in RL95-2 cells by the newly isolated cDNA but not by the first 180 base pair of the published hERR1 sequence. By Western analysis, a major 42-kDa protein is detected in the RL95-2 nuclear extract with antibody generated against GST-hERR1 fusion protein. Finally, we show that the hERR1 interacts with the human estrogen receptor through protein-protein contacts.

Effect of interferon-gamma on antigen-induced eosinophil infiltration into the mouse airway

OBJECTIVE

To investigate whether murine recombinant interferon-gamma (IFN-gamma) is capable of inhibiting antigen-induced eosinophil (EOS) infiltration into the mouse airway.

MATERIALS AND METHODS

BALB/c mice were sensitized and challenged repeatedly with ovalbumin (OVA) to develop an allergic airway inflammation model. The experimental mice were given injection of different doses of IFN-gamma. The numbers of EOS in bronchoalveolar lavage fluid (BALF) from each group were counted, and concentrations of interleukin (IL)-5 in supernatants of cultured spleen cells were detected.

RESULTS

In sensitized mice challenged with OVA 20 minutes once a day for 6 days, the number of BLAF EOS was 9.53 +/- 0.84 x 10(5)/ml. However, no EOS could be found in BALF from mice without OVA sensitization and challenge. In mice treated with IFN-gamma, doses of IFN-gamma (1.0 x 10(3), 1.0 x 10(4), 1.0 x 10(5)U/KG) produced 29.8% (P < 0.05), 55.7% (P < 0.01), and 69.0% (P < 0.01) inhibition of eosinophilia, respectively. The results also showed that IFN-gamma prevented antigen-induced EOS recruitment into airway accompanied be decrement of levels of IL-5 with a dose-related response.

CONCLUSION

IFN-gamma is capable of inhibiting EOS infiltration into mouse airway by inhibiting the production of IL-5. Our results suggested that IFN-gamma may be of value in treating asthma in human beings.

Effects of calcium on the migration and recruitment of macrophages and macrophage-derived foam cells

Calcium is thought to play an important role in the genesis of atherosclerotic lesions, but the precise mechanisms involved are unclear. In the present investigation, we have used in vitro systems to investigate the effects of calcium on one key aspect of lesion development: the migration of macrophages and macrophage/foam cells. Using agarose plate migration assays, the migratory characteristics of macrophages exposed to 1) no lipoprotein, 2) low density lipoprotein (LDL), 3) acetylated low density lipoprotein (acLDL), and ) oxidized low density lipoprotein were examined. The most marked stimulatory effect on macrophage mobility was observed when freshly isolated cells were exposed to acLDL during the migration assay. High levels of exogenous calcium were found to suppress the stimulatory effect of acLDL on migration. As the responses of macrophages exposed to a uniform concentration of agents in the surrounding medium may differ from chemotactic responses to a concentration gradient, the migration of macrophages, with and without preexposure to acLDL or LDL, was studied using microchemotaxis Boyden chambers. Under these conditions, calcium acted as a highly potent chemoattractant, especially to cells that had been preincubated with acLDL. These results suggest how elevated external calcium concentration leads initially to macrophage recruitment, and subsequently to foam cell aggregation and lipid core formation, in association with calcification, in the developing atherosclerotic plaque.

[Effects of a platelet-activating factor antagonist ONO-6240 on antigen induced eosinophil infiltration into the airways]

An in vivo mouse model of allergic bronchial asthma was developed to investigate the effects of a platelet activating factor antagonist ONO-6240 on eosinophil (EOS) recruitment into the mouse airway. In the present study, no EOS could be found in bronchoalveolar lavage fluid (BALF) from normal control mice. However, chronic ovalbumin challenge of sensitized mice induced significant bronchoalveolar eosinophilia (9.68 +/- 0.72 x 10(8)/L). In three groups of mice treated intraperitoneally with different doses of ONO-6240 (0.1, 1.0, 10.0 mg/kg), the medication produced 42.1% (5.60 +/- 0.97 x 10(8)/L, P < 0.01), 58.8% (3.99 +/- 0.84 x 10(8)/L, P < 0.01), and 72.6% (2.65 +/- 0.71 x 10(8)/L, P < 0.01) inhibition, respectively, of the antigen-induced influx of EOS into BALF. It was found that the prevention of EOS infiltration into airway with ONO-6240 was accompanied by decrements of both interleukin (IL)-5 and IL-2 levels. These data indicated that ONO-6240 prevented airway eosinophilia by inhibiting production of IL-5 and IL-2. Our results suggested that ONO-6240 may be of value in treating human asthmatic patients.

[Low dosage of homoharringtonine for prevention of cicatrization after glaucoma filtering surgery]

To prevent the cicatrization of filtering blebs after glaucoma filtering surgery, subconjunctival injections of low dosage homoharringtonine were administered to 22 glaucomatous eyes (20 patients) postoperatively. The percentage of functional filtering blebs was 90.9% and the mean postoperative IOP was 2.04 +/- 0.68 kPa (1 kPa = 7.5 mmHg). In comparison with the control group, the differences were very significant (P < or = 0.01). The results suggest that the toxicity of low dosage of homoharringtonine be very low, it inhibit fibroblast proliferation and play important roles in the formation of the functional filtering blebs and elevation of the success rate of filtration operation.

Quantitative determination of serum iron in human blood by high-performance capillary electrophoresis

A capillary electrophoretic (HPCE) method that can be used to quantitatively determine trace amounts of iron has been developed and applied to determine the iron level in human serum. After precipitation of serum proteins, Fe(III) in the serum is reduced to Fe(II) with hydroxylamine hydrochloride, and a stable Fe(II)-1,10-phenanthroline complex is formed by adding 1,10-phenanthroline to the supernatant containing 2.5 mM ammonium acetate-acetic acid at pH 5.0. The Fe(II)-1,10-phenanthroline complex, [Fe(C12H8N2)3]2+, has a very strong absorbance at 270 nm (with a molar absorptivity of approximately 9.2.10(4)). By measuring the absorbance of [Fe(C12H8N2)3]2+ at 270 nm, the iron level in human serum can be precisely quantified. The interference from copper, a major interference in serum, can be totally eliminated due to the complete separation of [Fe(C12H8N2)3]2+ and the Cu(II)-1,10-phenanthroline complex. In addition, other problems that usually occurred with conventional spectrophotometric methods, such as co-precipitation and occlusion of iron during sample pretreatment, are significantly minimized due to the ability to wash the precipitate and the higher detection sensitivity. With this method, a single drop (10 microliters) of serum would be sufficient to determine the serum iron concentration. The method is reliable, sensitive, rapid and reproducible. Thus it is highly suitable for use in the clinical laboratory.

A role for increased lutropin/choriogonadotropin receptor (LHR) gene transcription in the follitropin-stimulated induction of the LHR in granulosa cells

Follitropin (FSH) has been shown in previous studies to stimulate the induction of the LH/CG receptor (LHR) and LHR mRNA in the granulosa cells of diethylstilbesterol-primed immature rats. The present studies were undertaken to identify the mechanisms underlying the hormone-dependent induction of the LHR in rat granulosa cells. The effect of FSH on LHR mRNA stability was determined by measuring the decay of LHR mRNA after removal of FSH under conditions where transcription was inhibited. Under these conditions, readdition of FSH had little effect on mRNA stability. However, inhibitors of transcription themselves were found to have a marked effect on stabilizing the LHR mRNA, thus potentially masking an effect of FSH. These results suggest that there is a labile destabilizing factor that constitutively degrades LHR mRNA. At present, it cannot be ascertained whether FSH has any effect on this destabilizing factor. Transcriptional activity of the LHR gene was examined using nuclear run-on assays. It was found that 1) in the absence of FSH, LHR-binding activity and mRNA levels were negligible, but the LHR gene was transcriptionally active in granulosa cells of immature rats; 2) incubations of granulosa cells with FSH or 8-bromo-cAMP significantly increased endogenous LHR gene transcription (approximately 10-fold) under conditions where increases in LHR mRNA were observed; 3) the continuous presence of FSH or 8-bromo-cAMP was required to maintain elevated levels of LHR gene transcription and LHR mRNA; and 4) exogenous estradiol alone had no effect on transcription of the LHR gene although it was able to synergistically enhance FSH-induced LHR expression. These experiments suggest that while the effects of estradiol on LHR induction do not appear to be mediated by an increase in LHR gene transcription, the effects of FSH (or cAMP) on LHR induction are clearly mediated, at least in part, by significant increases in the rate of LHR gene transcription.

Scavenging effects of baicalin on free radicals and its protection on erythrocyte membrane from free radical injury

Using electron spin resonance (ESR) spin trapping technique, we found that baicalin (B) could scavenge hydroxyl radicals generated from Fenton reaction. It also could scavenge superoxide radicals generated from the reaction system containing xanthine (X) and xanthine oxidase (XO), as was found by using chemiluminescence (CL) method. Kinetic studies on the competition between baicalin and a spin trap 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) in trapping OH showed that baicalin had a kinetic reactive rate constant of the order of 7.7 x 10(11) M-1 s-1 in its reaction with OH, and the studies on the competition between baicalin and ferricytochrome c (f.c.) in trapping O2- gave a kinetic reactive rate constant of 3.2 x 10(6) M-1 s-1 for baicalin in its reaction with O2-. Furthermore, we have investigated the protective effects of baicalin on erythrocyte membranes from hydroxyl free radical injuries. The results showed that baicalin could reduce hydrogen peroxide-induced hemolysis, protect the conformation of sulfhydryl groups (-SH) on membrane proteins and the membrane fluidity of erythrocytes incubated with hydrogen peroxide. The results indicated that baicalin could protect the membranes of erythrocytes from free radical injuries, and it was even more effective than alpha-tocopherol.

Determination of vitamin A in dried human blood spots by high-performance capillary electrophoresis with laser-excited fluorescence detection

We have developed a high-performance capillary electrophoresis (HPCE) method to analyze the retinol (vitamin A) concentration as retinol-retinol binding protein (holo-RBP) from microvolumes of serum (5-10 microliters) or one to two drops (approximately 20 microliters) of blood collected and air-dried on blood collection filter paper. A 0.64-cm diameter disk was cut from the dried whole blood specimens and the samples were dissolved in a pretreatment buffer and filtered. Filtrate was injected onto the HPCE column for analysis. The separation was carried out in a 60 cm x 50 microns I.D. fused-silica capillary and the running voltage was 20 kV. A He-Cd laser with a wavelength of 325 nm was used for excitation, and the fluorescence of the holo-RBP complex was monitored at 465 nm by a photodiode. A virtual linear relationship was obtained for the retinol concentrations between HPCE and HPLC for 28 serum samples, 19 dried venous blood samples and 9 capillary dried blood spot samples, indicating that valid measures of serum retinol can be obtained from one to two drops of capillary blood collected on filter paper. The absolute detection limit for retinol by HPCE is below 3 micrograms/l. The method is very useful for vitamin A level screening, especially for children and premature new-born babies.