[Analysis of the feasibility and prognostic value of circulating tumor DNA monitoring in detecting gene mutations in patients with diffuse large B-cell lymphoma receiving chimeric antigen receptor T-cell therapy]

Objective: To explore the prognostic value of circulating tumor DNA (ctDNA) testing in patients with refractory/relapsed diffuse large B-cell lymphoma (R/R DLBCL) undergoing chimeric antigen receptor T-cell (CAR-T) therapy, and to guide the prevention and subsequent treatment of CAR-T-cell therapy failure. Methods: In this study, 48 patients with R/R DLBCL who received CAR-T-cell therapy at the First Affiliated Hospital of Zhejiang University School of Medicine between December 2017 and March 2022 were included. Furthermore, ctDNA testing of 187 lymphoma-related gene sets was performed on peripheral blood samples obtained before treatment. The patients were divided into complete remission and noncomplete remission groups. The chi-square test and t-test were used to compare group differences, and the Log-rank test was used to compare the differences in survival. Results: Among the patients who did not achieve complete remission after CAR-T-cell therapy for R/R DLBCL, the top ten genes with the highest mutation frequencies were TP53 (41%), TTN (36%), BCR (27%), KMT2D (27%), IGLL5 (23%), KMT2C (23%), MYD88 (23%), BTG2 (18%), MUC16 (18%), and SGK1 (18%). Kaplan-Meier survival analysis revealed that patients with ctDNA mutation genes >10 had poorer overall survival (OS) rate (1-year OS rate: 0 vs 73.8%, P<0.001) and progression-free survival (PFS) rate (1-year PFS rate: 0 vs 51.8%, P=0.011) compared with patients with ctDNA mutation genes ≤10. Moreover, patients with MUC16 mutation positivity before treatment had better OS (2-year OS rate: 56.8% vs 26.7%, P=0.046), whereas patients with BTG2 mutation positivity had poorer OS (1-year OS rate: 0 vs 72.5%, P=0.005) . Conclusion: ctDNA detection can serve as a tool for evaluating the efficacy of CAR-T-cell therapy in patients with R/R DLBCL. The pretreatment gene mutation burden, mutations in MUC16 and BTG2 have potential prognostic value.

Systolic Blood Pressure and Mortality in Community-Dwelling Older Adults: The Role of Frailty

OBJECTIVES

To investigate whether frailty modifies the association of systolic blood pressure (SBP) with cardiovascular mortality and all-cause mortality in community-dwelling older adults.

DESIGN

A prospective cohort study.

SETTING

A population-based study of nationally representative older Chinese adults in a community setting.

PARTICIPANTS

This study included participants aged 65 years or older from the Chinese Longitudinal Healthy Longevity Survey 2002-2014 and followed up to 2018.

MEASUREMENTS

Participants were divided into two groups according to a frailty index based on the accumulation of a 44-items deficits model. The association between SBP and mortality was analyzed using multivariable-adjusted Cox proportional hazards models.

RESULTS

Among 18,503 participants included, the mean age was 87.2 years and the overall median follow-up time was 42.7 months. We identified 7808 (42.2%) frail participants (mean frailty index=0.33), in which 7533 (96.5%) died during the follow-up. Effect modification by frailty was detected (P for interaction=0.032). Among frail participants, a U-shaped association was found with hazard ratios of 1.16 (95% CI, 1.02-1.32) for SBP < 100 mmHg, and 1.11 (95% CI, 1.00-1.24) for SBP ≥ 150 mmHg compared with SBP 120-130 mmHg. For non-frail older adults, a tendency toward higher risk among those with SBP ≥ 130 mmHg was observed. The analyses towards cardiovascular mortality showed similar results.

CONCLUSION

Our results suggest the presence of effect modification by frailty indicating a possible negative effect for elevated SBP in non-frail older adults and a U-shaped relationship of SBP in frail older adults with respect to mortality even after adjusting for diastolic blood pressure.

Anti-tumor role of Bacillus subtilis fmbJ-derived fengycin on human colon cancer HT29 cell line

To explore the potential clinical anti-tumor roles of Bacillus subtilis fmbJ-derived fengycin on cell growth and apoptosis in colon cancer HT29 cell line.Fengycin was extracted from Bacillus subtilis fmbJ and detected using HPLC. The effects of different concentration of fengycin on colon cell HT29 cell activity at different time points were analyzed using MTT assay. ROS level in colon HT29 cells affected by fengycin was detected using DCFH-DA method, followed by measuring the effects of fengycin on HT29 cell apoptosis and cell cycle by flow cytometry. The effects of fengycin on Bax/Bcl-2, CDK4/cyclin D1, Caspase-6 and Caspase-3 expressions in HT29 cells were analyzed using western blot. Also, mRNA levels of Bax/Bcl-2 and CDK4/cyclin D1 in HT29 cells affected by fengycin were analyzed using qRT-PCR.Compared with controlss, 20 μg/mL of fengycin performed an inhibit role on HT29 cell growth of at 3 day (P<0.05), and high dose of fengycin showed more excellent effect on inhibiting HT29 cell growth with time increasing. Besides, fengycin could induce HT29 cell apoptosis and affect the cell cycle arrest at G1. ROS level in HT29 cells treated by fengycin was significantly increased compared with that in control group (P<0.05). Western blot analysis showed that after being treated with fengycin, Bax, Caspase-3, and Caspase-6 expressions were increased, however, Bcl-2, and CDK4/cyclin D1 expressions were decreased (P<0.05).Our study suggested that fengycin may play certain inhibit roles in the development and progression of colon cancer through involving in the cell apoptosis and cell cycle processes by targeting the Bax/Bcl-2 pathway.

Association between interleukin-17 gene polymorphisms and the risk of laryngeal cancer in a Chinese population

IL-17 is associated with the occurrence and development of laryngeal cancer. However, no study has reported the association between IL-17 polymorphisms and laryngeal cancer susceptibility. Therefore, we analyzed the association of three polymorphism loci (rs2275913, 197 G/A; rs3748067, 383 A/G; and rs763780, 7488 T/C) of IL-17A and IL-17F with laryngeal cancer in the Chinese population. A case-control study was performed with 325 patients and 325 controls. Polymorphisms were detected by polymerase chain reaction and sequencing methods. SPSS17.0 software was used for statistical analysis. Allele and genotype frequencies of IL-17A rs2275913 were significantly different between patients and controls (P < 0.05). Frequencies of rs2275913 (197 G/A) AA and GA+AA genotypes compared to the GG genotype were significantly higher in patients than in controls, indicating the association of these genes with laryngeal cancer susceptibility; adjusted OR values were 2.54 (1.50-4.23) and 1.62 (1.19-2.17), respectively. Furthermore, individuals with the GA+AA genotype, compared to the GG genotype, aged ≤60 years, with smoking and alcohol consumption habits, and without a family history of cancer showed a higher cancer risk (OR = 2.74, 95%CI = 1.41-5.23; OR = 2.11, 95%CI = 1.21-3.55; OR = 1.91, 95%CI = 1.02-3.70; OR = 1.99, 95%CI = 1.08-3.39, respectively). In conclusion, the rs2275913 IL-17A (197 G/A) is associated with the incidence and development of laryngeal cancer in the Chinese population, and the AA and GA+AA genotypes harbor a high laryngeal cancer risk.

Synthesis and Characterisation of 4-Aminophthalimido-N-Alkyl-Calix[4]Azacrown Derivatives

Two 4-amino-N-bromoalkylphthalimide derivatives were prepared by the reduction of 4-nitro-N-bromoalkylphthal-imides and SnCl2 and reacted with calix[4]azacrown to give two new 4-aminophthalimido-N-alkyl-calix[4]azacrown derivatives. They were characterised by IR, 1H NMR, 13C NMR and HRMS and shown to adopt a cone conformation, 4-aminophthalimido-N-alkyl-calix[4]azacrown may provide a potential fluorescent probe for Cu2+.

Resveratrol inhibits the expression of SREBP1 in cell model of steatosis via Sirt1-FOXO1 signaling pathway

Recent studies in mice have shown that resveratrol can protect the liver from fat accumulation induced by high fat diet. However, the exact mechanism is largely unknown. To explore the possible mechanism, we investigated the anti-lipogenic effect of resveratrol in vitro model. Oil Red O staining revealed that resveratrol could significantly ameliorate the excessive triglyceride accumulation in HepG2 cells induced by palmitate. The results of RT-PCR and Western blotting showed that resveratrol upregulated the expression of Sirt1 and forkhead box O1 (FOXO1), whereas downregulated the expression of sterol regulatory element binding protein1 (SREBP1). Moreover, resveratrol was shown to inhibit the activity of SREBP1, as evaluated by immunofluorescence assay. Our results suggest that resveratrol may attenuate fat deposition by inhibiting SREBP1 expression via Sirt1-FOXO1 pathway and thus may have application for the treatment of NAFLD.

Pick's disease with Pick bodies combined with progressive supranuclear palsy without tuft-shaped astrocytes: a clinical, neuroradiologic and pathological study of an autopsied case

We report clinical, neuroradiologic features, and neuropathologic findings of a 76-year-old man with coexistent Pick's disease and progressive supranuclear palsy. The patient presented with loss of recent memory, abnormal behavior and change in personality at the age of 60. The symptoms were progressive. Three years later, repetitive or compulsive behavior became prominent. About 9 years after onset, he had difficulty moving and became bedridden because of a fracture of his left leg. His condition gradually deteriorated and he developed mutism and became vegetative. The patient died from pneumonia 16 years after the onset of symptoms. Serial MRI scans showed progressive cortex atrophy, especially in the bilateral frontal and temporal lobes. Macroscopic inspection showed severe atrophy of the whole brain, including cerebrum, brainstem and cerebellum. Microscopic observations showed extensive superficial spongiosis and severe neuronal loss with gliosis in the second and third cortical layers in the frontal, temporal and parietal cortex. There were Pick cells and argyrophilic Pick bodies, which were tau- and ubiquitin-positive in neurons of layers II-III of the above-mentioned cortex. Numerous argyrophilic Pick bodies were observed in the hippocampus, especially in the dentate fascia. In addition, moderate to severe loss of neurons was found with gliosis and a lot of Gallyas/tau-positive globus neurofibrillary tangles in the caudate nucleus, globus pallidus, thalamus, substantia nigra, locus coeruleus and dentate nucleus. Numerous thorned-astrocytes and coiled bodies but no-tuft shaped astrocytes were noted in the basal ganglion, brainstem and cerebellar white matter. In conclusion, these histopathological features were compatible with classical Pick's disease and coexistence with progressive supranuclear palsy without tuft-shaped astrocytes.

Measurement of the nitric oxide metabolites nitrate and nitrite in the human brain by microdialysis

To examine the feasibility of measuring the nitric oxide (NO) metabolites nitrate and nitrite in microdialysate samples from the human brain, microdialysis probes were placed in normal appearing cerebral cortex of severely head injured patients in the Neurosurgical Intensive Care Unit at Ben Taub General Hospital. Nitrate/nitrite analysis was performed using NO chemiluminescence. Low micromolar levels of NO metabolites were consistently and easily detected. These levels seen are comparable to levels reported in CSF but tissue tortuosity and probe recovery considerations suggest that the absolute concentrations at the probe site are probably ten fold higher. Microdialysis with measurement of nitric oxide metabolites is technically feasible and may provide valuable insights into both normal neurochemistry and neurochemical derangements in disease.

[Advances in solid phase microextraction coupled with high performance liquid chromatography]

Solid phase microextraction (SPME) is a solvent-free technique with high extraction efficiency and easy to perform automatically. It can be coupled with high performance liquid chromatography to perform efficient analysis of compounds with high polarity. The advances in solid phase microextraction coupled with high performance liquid chromatography, including its theory, interfaces, coating materials and applications, are reviewed with 36 references.

Sequences flanking hypersensitive sites of the beta-globin locus control region are required for synergistic enhancement

The major distal regulatory sequence for the beta-globin gene locus, the locus control region (LCR), is composed of multiple hypersensitive sites (HSs). Different models for LCR function postulate that the HSs act either independently or synergistically. To test these possibilities, we have constructed a series of expression cassettes in which the gene encoding the enhanced green fluorescent protein (EGFP) is under the control of DNA fragments containing single and multiple HSs of the LCR. LCR DNA fragments containing only the minimal region needed for position-independent expression (HS cores) or containing cores plus flanking sequences (HS units) were compared to ascertain whether conserved sequences between the HS cores contributed to enhancement. Expression of these constructs was measured after targeted integration into three defined loci in murine erythroleukemia cells using recombinase-mediated cassette exchange. At all three marked loci, synergistic enhancement of expression was observed in cassettes containing a combination of HS2, HS3, and HS4 units. In contrast, HS2, HS3, and HS4 cores (without flanking sequences) give an activity equivalent to the sum of the activities of the individual HS cores. These data suggest a model in which an HS core plus flanking regions, bound by specific proteins, forms a structure needed for interaction with other HS units to confer strong enhancement by the LCR. The three targeted integration sites differ substantially in their permissivity for expression, but even the largest LCR construct tested could not overcome these position effects to confer equal expression at all three sites.

Position effects are influenced by the orientation of a transgene with respect to flanking chromatin

We have inserted two expression cassettes at tagged reference chromosomal sites by using recombinase-mediated cassette exchange in mammalian cells. The three sites of integration displayed either stable or silencing position effects that were dominant over the different enhancers present in the cassettes. These position effects were strongly dependent on the orientation of the construct within the locus, with one orientation being permissive for expression and the other being nonpermissive. Orientation-specific silencing, which was observed at two of the three site tested, was associated with hypermethylation but not with changes in chromatin structure, as judged by DNase I hypersensitivity assays. Using CRE recombinase, we were able to switch in vivo the orientation of the transgenes from the permissive to the nonpermissive orientation and vice versa. Switching from the permissive to the nonpermissive orientation led to silencing, but switching from the nonpermissive to the permissive orientation did not lead to reactivation of the transgene. Instead, transgene expression occurred dynamically by transcriptional oscillations, with 10 to 20% of the cells expressing at any given time. This result suggested that the cassette had been imprinted (epigenetically tagged) while it was in the nonpermissive orientation. Methylation analysis revealed that the methylation state of the inverted cassettes resembled that of silenced cassettes except that the enhancer had selectively lost some of its methylation. Sorting of the expressing and nonexpressing cell populations provided evidence that the transcriptional oscillations of the epigenetically tagged cassette are associated with changes in the methylation status of regulatory elements in the transgene. This suggests that transgene methylation is more dynamic than was previously assumed.

Genomic targeting of methylated DNA: influence of methylation on transcription, replication, chromatin structure, and histone acetylation

We have developed a strategy to introduce in vitro-methylated DNA into defined chromosomal locations. Using this system, we examined the effects of methylation on transcription, chromatin structure, histone acetylation, and replication timing by targeting methylated and unmethylated constructs to marked genomic sites. At two sites, which support stable expression from an unmethylated enhancer-reporter construct, introduction of an in vitro-methylated but otherwise identical construct results in specific changes in transgene conformation and activity, including loss of the promoter DNase I-hypersensitive site, localized hypoacetylation of histones H3 and H4 within the reporter gene, and a block to transcriptional initiation. Insertion of methylated constructs does not alter the early replication timing of the loci and does not result in de novo methylation of flanking genomic sequences. Methylation at the promoter and gene is stable over time, as is the repression of transcription. Surprisingly, sequences within the enhancer are demethylated, the hypersensitive site forms, and the enhancer is hyperacetylated. Nevertheless, the enhancer is unable to activate the methylated and hypoacetylated reporter. Our findings suggest that CpG methylation represses transcription by interfering with RNA polymerase initiation via a mechanism that involves localized histone deacetylation. This repression is dominant over a remodeled enhancer but neither results in nor requires region-wide changes in DNA replication or chromatin structure.

Myocardial extracellular matrix remodeling in transgenic mice overexpressing tumor necrosis factor alpha can be modulated by anti-tumor necrosis factor alpha therapy

Myocardial fibrosis caused by maladaptive extracellular matrix (ECM) remodeling is implicated in the dysfunction of the failing heart. Matrix metalloproteinases (MMPs) regulate ECM remodeling, and are regulated by cytokines. Transgenic mice with cardiac-specific overexpression of tumor necrosis factor alpha (TNF-alpha) (TNF1.6) develop heart failure. We hypothesized that modulation of TNF-alpha and/or MMP activity might alter the myocardial ECM remodeling process and the development of heart failure. To test this hypothesis, we took advantage of the TNF1.6 mice and studied soluble and total collagens and collagen type profiling by using hydroxyproline quantification, Sircol collagen assay, Northern blot analysis, and immunohistochemistry and studied myocardial function by using echocardiography. Progressive ventricular hypertrophy and dilation in the TNF1.6 mice were accompanied by a significant increase in MMP-2 and MMP-9 activity, an increase in collagen synthesis, deposition, and denaturation, and a decrease in undenatured collagens. In young TNF1.6 mice, these changes in the ECM were associated with marked diastolic dysfunction as demonstrated by significantly reduced transmitral Doppler echocardiographic E/A wave ratio. Anti-TNF-alpha treatment with adenoviral vector expressing soluble TNF-alpha receptor type I attenuated both MMP-2 and MMP-9 activity, prevented further collagen synthesis, deposition and denaturation, and preserved myocardial diastolic function in young, but not old, TNF1.6 mice. The results suggest a critical role of TNF-alpha and MMPs in myocardial matrix remodeling and functional regulation and support the hypothesis that both TNF-alpha and MMPs may serve as potential therapeutic targets in the treatment of heart failure.

[Advances of capillary electrophoresis and capillary electrochromatography using ionic coating column]

Capillary electrochromatography (CEC) is a promising micro-separation technique, which combines the high selectivity of HPLC and the high efficiency of HPCE. In comparing to CE with fused silica capillary and CEC with ODS stationary phase, capillary electrophoresis and capillary electrochromatography with ionic coating columns can cause EOF more controllable, and provide an alternative separation mechanism. Therefore, the new CEC and CE modes are in favor of optimizing the separation and broadening the range of samples for analysis. The development of capillary electrophoresis and capillary electrochromatography using ionic coating column is reviewed with 48 references.

[Preparation and evaluation of glycine derivatized beta-cyclodextrin bonded silica for high performance liquid chromatography]

Glycine derivatized beta-cyclodextrin bonded silica (GCDS) has been prepared for high performance liquid chromatography through the reactions of beta-cyclodextrin bonded silica with tosyl chloride and glycine in sequence. The separation performance of GCDS for positional isomers, dansyl amino acids and phenylpropionic acids was investigated. It was found that nitrophenols could not be eluted with methanol as mobile phase, but could be eluted with methanol-phosphate buffer solution within appropriate time, which was much different from the behavior observed on native beta-cyclodextrin bonded silica. The effect of column temperature on the enantio-separation of dansyl D,L-Phe with GCDS was examined. The results show that the enantio-separation ability of the GCDS decreases with the increase of the column temperature. Other factors such as methanol concentration and pH of the mobile phase influencing the retention behavior of solutes on the GCDS are also discussed.

[Retention behavior of some polycyclic aromatic hydrocarbons on alkylphosphonate-modified magnesia-zirconia composite stationary phase for reversed-phase liquid chromatography]

An alkylphosphonate-modified magnesia-zirconia composite stationary phase (PZMS) for reversed-phase liquid chromatography was prepared. The reversed-phase chromatographic performance of the new packing material was investigated with some polycyclic aromatic hydrocarbons (PAHs) as solutes. The effect of the methanol content in the mobile phase on the retention of PAHs was examined. The logarithmic capacity factor of PAHs was decreased linearly with increasing volume percent of the methanol in the mobile phase, which is similar to that observed on Zorbax ODS. The capacity factor of PAHs on the new stationary phase was also correlated to their partition coefficient between n-octanol and water (log P). A good linear relationship between them was obtained. These results show that the new material can behave as a reversed-phase packing. The separations of phenanthrene and anthracene, and terphenyl isomers were investigated on the new stationary phase and the Zorbax ODS, respectively. The retention of the solutes on the Zorbax ODS is greater than that on the new stationary phase, but the separation selectivity of the solutes on the new stationary phase is better than that on the Zorbax ODS. The better separation selectivity on the new stationary phase may be contributed from the Lewis acid-base interaction between the solutes and the residual Lewis acid sites on the stationary phase.

Beta-globin YAC transgenes exhibit uniform expression levels but position effect variegation in mice

Expression of a construct integrated at different genomic locations often varies because of position effects that have been subcategorized as stable (decreased level of expression) and variegating (decreased proportion of expressing cells). It is well established that locus control regions (LCRs) generally overcome position effects in transgenes. However, whether stable and variegated position effects are equally overcome by an intact LCR has not been determined. We report that single-copy yeast artificial chromosome transgenes containing an unmodified human beta -globin locus were not subject to detectable stable position effects but did undergo mild to severe variegating position effects at three of the four non-centromeric integration sites tested. We also find that, at a given integration site, the distance and the orientation of the LCR relative to the regulated gene contributes to the likelihood of variegating position effects, and can affect the magnitude of its transcriptional enhancement. DNase I hypersensitive site (HSS) formation varies with the proportion of expressing cells, not the level of gene expression, suggesting that silencing of the transgene is associated with a lack of HSS formation in the LCR region. We conclude that transcriptional enhancement and variegating position effects are caused by fundamentally different but inter-dependent mechanisms.

Deletions within the mouse beta-globin locus control region preferentially reduce beta(min) globin gene expression

The mouse beta-globin gene cluster is regulated, at least in part, by a locus control region (LCR) composed of several developmentally stable DNase I hypersensitive sites located upstream of the genes. In this report, we examine the level of expression of the beta(min) and beta(maj) genes in adult mice in which HS2, HS3, or HS5,6 has been either deleted or replaced by a selectable marker via homologous recombination in ES cells. Primer extension analysis of RNA extracted from circulating reticulocytes and HPLC analysis of globin chains from peripheral red blood cells revealed that all mutations that reduce the overall output of the locus preferentially decrease beta(min) expression over beta(maj). The implications of these findings for the mechanism by which the LCR controls expression of the beta(maj) and beta(min) promoters are discussed.

Site-specific chromosomal integration in mammalian cells: highly efficient CRE recombinase-mediated cassette exchange

Expression of experimental constructs in mammalian cells or transgenic animals is difficult to control because it is markedly influenced by position effects. This has limited both the analysis of cis -DNA regulatory elements for transcription and replication, and the physiological analysis of proteins expressed from transgenes. We report here two new methods based on the concept of recombinase-mediated cassette exchange (RMCE) to perform site-specific chromosomal integration. The first method permits the exchange of a negative selectable marker pre-localized on the chromosome with a transgene via a CRE-mediated double recombination between inverted Lox sites. Integration efficiency is close to 100 % of negatively selected mouse erythroleukemia cells and ranges from 10 to 50 % in embryonic stem cells. The second method allows RMCE with no selection at all except for cells that have taken up plasmid transiently. While less efficient, this technique permits novel experimental approaches. We find that integration of a transgene at a given genomic site leads to reproducible expression. RMCE should be useful to develop artificial genetic loci that impart specific and reproducible regulation of transgenes in higher eukaryotes. This should facilitate the analysis of cis -regulatory DNA elements governing expression and position effects, improve our control over the physiological effects of transgenes, and accelerate the development of animal models for complex human diseases.

Enhancer-dependent transcriptional oscillations in mouse erythroleukemia cells

By using recombinase-mediated cassette exchange, a method that allows integration of single copies of different constructs at the same predetermined chromosomal location, several expression cassettes have been integrated at a randomly chosen locus in the genome of mouse erythroleukemia cells. The cassettes studied contain the human beta-globin promoter fused to lacZ coding sequences either alone or linked to DNase I-hypersensitive site HS2, HS3, or HS234 (a large locus control region fragment containing HS2, HS3, and HS4) of the human beta-globin locus control region. Analysis of expression of these cassettes revealed mosaic expression patterns reminiscent of, but clearly different from, position effect variegation. Further investigations demonstrated that these mosaic expression patterns are caused by dynamic activation and inactivation of the transcription unit, resulting in oscillations of expression. These oscillations occur once in every few cell cycles at a rate specific for the enhancer present at the locus. DNase I sensitivity studies revealed that the chromatin is accessible and that DNase-hypersensitive sites were present whether or not the transcription unit is active, suggesting that the oscillations occur between transcriptionally competent and transcriptionally active chromatin conformations, rather than between open and closed chromatin conformations. Treatment of oscillating cells with trichostatin A eliminates the oscillations only after the cells have passed through late G1 or early S, suggesting that these oscillations might be caused by changes in histone acetylation patterns.

Anti-beta s-ribozyme reduces beta s mRNA levels in transgenic mice: potential application to the gene therapy of sickle cell anemia

Our current strategy for gene therapy of sickle cell anemia involves retroviral vectors capable of transducing "designer" globin genes that code for novel anti-sickling globins (while resisting digestion by a ribozyme), coupled with the expression of a hammerhead ribozyme that can selectively cleave the human beta s mRNA. In this report, we have tested in vivo an anti-beta s hammerhead ribozyme embedded within a cDNA coding for the luciferase reporter gene driven by the human beta-globin promoter and hyper-sensitive sites 3 and 4 of the locus control region. We have created mice transgenic for this luciferase-ribozyme construct and bred the ribozyme transgene into mice that were already transgenic for the human beta s gene. We then measured expression of the beta s transgene at the protein and RNA levels by HPLC and primer extension. The presence of the ribozyme was associated with a statistically significant reduction in the level of beta s mRNA in spleen stress reticulocytes (from 60.5 +/- 4.1% to 52.9 +/- 4.2%) and in the percentage of beta s globin chains in very young mice (from 44.5 +/- 0.6% to 40.8 +/- 0.7%). These results demonstrate that it is possible to decrease the concentration of beta s chains and mRNA with the help of a hammerhead ribozyme. While the enormous amount of globin mRNA in reticulocytes is a challenge for ribozyme technology, the exquisite dependence of the delay time for formation of Hb S nuclei on the concentration of Hb S in red blood cells suggests that even a modest reduction in Hb S concentration would have therapeutic value.

[Immunocytochemical study of mononuclear cells in peripheral blood and cerebrospinal fluid of patients with Japanese B encephalitis]

Using the technique of monoclonal antibody-immunogold-silver staining (M-IGSS), the mononuclear cells in peripheral blood (PB) and cerebrospinal fluid (CSF) were screened for immunoreactivity against JBE virus antigen (JBEV-Ag), interleukin-2 receptor (Tac), class II human leucocyte antigen (HLA-DR) and interferon-r (IFN-r) in 17 ELISA diagnosed JEB patients and 17 control cases with non-inflammatory and non-immunological diseases. It was found that JBEV-Ag+ cells were present in PB (16/17) and CSF (12/17) of the JBE group, but absent in both the control group and another 5 cases with mumps virus meningitis. The percentages of Tac+, HLA-DR+ and IFN-r+ cells in JBE patients were higher than those in controls.

[Microwave technique in hepatic surgery: report of 70 cases]

70 hepatic resections were performed using 2450 MHz microwave scalpel. Primary diseased included hepatocellular carcinoma (46 cases), hemangioma (18), hepatobiliary tract stone (2), biliary cystadenoma (1), inflammatory pseudotumor of the live (1), metastatic liver cancer (2). Hemostasis was excellent despite liver cirrhosis in all cases. The average amount of blood loss and blood transfusion was 249 ml and 294 ml respectively. Blood transfusion was not necessary in 30 patients. All cases were free from postoperative bleeding from the liver stump and abdominal infection. No complications attributable to microwave coagulation were noted. We conclude that this new operative technique can be used safely and easily in the field of hepatic surgery.

Effect of heme binding on the structure and stability of Escherichia coli apocytochrome b562

The structure and stability of apocytochrome b562 were explored using absorption and circular dichroism spectroscopic methods. The polypeptide chain retains a well-defined structure when the prosthetic heme group is removed from cytochrome b562. Circular dichroism measurements estimate 60% helicity for apocytochrome b562, compared with 80% helicity found in holocytochrome b562. At low pH, apocytochrome b562 displays a midpoint pH of 2.9, while ferricytochrome b562 displays a midpoint pH of 2.3. The unfolding of the apoprotein by urea and heat can be well approximated by the two-state transition model. The stability of apocytochrome b562 is significantly reduced from that of the holoprotein. The free energy of stabilization (delta G degrees) and the midpoint transition temperature (Tm) for apocytochrome b562 are found to be 3.2 +/- 0.5 kcal/mol and 52.3 +/- 0.9 degrees C, respectively, compared with 6.6 +/- 0.5 kcal/mol and 67.2 +/- 0.5 degrees C for ferricytochrome b562. The smaller heat capacity change upon unfolding of apocytochrome b562 than that of ferricytochrome b562, estimated from the thermodynamic parameters, indicates that apocytochrome b562 possesses a smaller hydrophobic core than holocytochrome b562. Size-exclusion chromatography studies indicate that the apoprotein is slightly more extended in molecular dimension than ferricytochrome b562. The data suggest that apocytochrome b562 resembles a "molten globule" or a "collapsed form" of the holoprotein, in which secondary structure formation is largely complete while the global folding is either only partially complete or dynamically expanded.

1H and 15N NMR resonance assignments and preliminary structural characterization of Escherichia coli apocytochrome b562

The 1H and 15N resonances of uniformly enriched apocytochrome b562 (106 residues) have been assigned. The assignment work began with the identification of the majority of HN-H alpha-H beta subspin systems in two-dimensional DQF-COSY and TOCSY spectra of unlabeled protein in D2O and in 95% H2O/5% D2O buffer. Intraresidue and interresidue NOE connectivities were then searched for in two-dimensional homonuclear NOESY spectra recorded on unlabeled protein and in the three-dimensional NOESY-HMQC spectrum recorded on uniformly 15N-enriched protein. Those data, combined with the main-chain-directed assignment strategy (MCD), led to the assignment of the main-chain and many side-chain resonances of 103 of the 106 residues. Qualitatively, the helical conformation is found to be the dominant secondary structure in apocytochrome b562 as it is in holocytochrome b562. The helical segments in apocytochrome b562 overlap extensively with the helical regions defined in the crystal structure of ferricytochrome b562. In addition, a number of tertiary NOEs have been identified which indicate that the global fold of the apoprotein at least partially resembles the four-helix bundle of the holoprotein. The results presented here, together with the evidence obtained with other methods [Feng and Sligar (1991) Biochemistry (submitted)], support the notion that the interior of the protein is fluid and may correspond to a molten globule state.

Chemical exchange in two dimensions in the 1H NMR assignment of cytochrome c

The important role played by chemical exchange in solving the proton assignment problem for oxidized and reduced horse cytochrome c is described. Some novel approaches for establishing oxidation-reduction exchange correlations in combinations of several two-dimensional spectra were used. Unambiguous chemical exchange correlations were established for 55 NH-C alpha H resonances and all the aromatic and side chain methyl resonances. Consistent although not fully unambiguous main chain proton correlations were observed for 47 of the remaining 49 residues. The many exchange correlations found serve to multiply cross-connect the two extensive, individually self-consistent networks of assignments found for the oxidized and reduced forms, and thus help to confirm both sets of assignments.

[Hepatic inflammatory pseudotumor. A report of 5 cases]

Hepatic inflammatory pseudotumor (HIP) is rare. To our knowledge, there have only been 27 cases reported since 1953. We studied additional five cases, male, aged 13-56 years, with a history of the disease of 20 days-1 year. Major complains were epigastric pain, fever of unknown causes, and epigastric mass. All five HIPs were solitary and surgically resected with a final diagnosis made pathologically. HIPs mimic the characters of liver cancer on ultrasonography and CT scanning, however, the following several points could be used to establish the diagnosis: patients with a long history of hepatic tumor still in a rather good condition; patients with no cirrhosis and negative AFP test results; tumors that are well encapsulated, etc. Surgical exploration should be attempted in all patients unless in those with poor risks in which steroid therapy may prove useful.

[Inhibition of PHA-stimulated T cell conditioned medium (PHA-TCM) on the growth of human myeloid progenitor cells (CFU-C)]

Cord blood T cells were enriched by nylon wool colomn, and effects of PHA-stimulated T cell supernatant collected from 18 h to 7 days on the proliferation of CFU-c were studied. The results showed that the supernatant collected at 18 h (PHA-TCM) could significantly inhibit the growth of CFU-c and the inhibition was PHA-TCM dose dependent, suggesting there is a CFU-c inhibitory activity in PHA-TCM. Kinetic studies demonstrated that the activity was decreased in the supernatant collected at 48 h and disappeared at 7 days. On the other hand, unstimulated T cell supernatant and PHA alone had no inhibitory effect on CFU-c growth. Indomethacin did not affect the production of the inhibitory activity and no interferon activity could be detected in PHA-TCM. These suggested that the inhibition was mediated by a non-interferon, non-prostaglandin suppressor. Further studies revealed that the suppressor was a protein stable at 56 degrees C and lost in pH 2 and pH 11 for 3 h, its molecular weight was large than 10,000 dolton.

Assignment of paramagnetically shifted resonances in the 1H NMR spectrum of horse ferricytochrome c

The proton resonances of the heme, the axial ligands, and other hyperfine-shifted resonances in the 1H nuclear magnetic resonance spectrum of horse ferricytochrome c have been investigated by means of one- and two-dimensional nuclear Overhauser and magnetization transfer methods. Conditions for saturation transfer experiments in mixtures of ferro- and ferricytochrome c were optimized for the cross assignment of corresponding resonances in the two oxidation states. New resonance assignments were obtained for the methine protons of both thioether bridges, the beta and gamma meso protons, the propionate six heme substituent, the N pi H of His-18, and the Tyr-67 OH. In addition, several recently reported assignments were confirmed. All of the resolved hyperfine-shifted resonances in the spectrum of ferricytochrome c are now identified. The Fermi contact shifts experienced by the heme and ligand protons are discussed.

[Effect of PHA-T cell conditioned medium (PHA-TCM) on leukemic cells]

Cord blood T cells, purified by nylon wool column, were incubated with PHA for 18 hours, and the supernatant were harvested as PHA-TCM. The results demonstrated that PHA-TCM could significantly inhibit the growth of U937 cells and reduce their 3H-TdR incorporation and spontaneous colony formation. After 3-6 days of treatment with PHA-TCM in culture, part of U937 cells became macrophage-like, latex-phagocytic, and capable of reducing NBT dye. On the contrary, HL-60 cells did not respond to PHA-TCM inhibition, indicating the selective effect of PHA-TCM.

Proton resonance assignments of horse ferrocytochrome c

Two-dimensional nuclear magnetic resonance (NMR) spectroscopy was used to assign the proton resonances of horse ferrocytochrome c. Assignments were based on the main chain directed (MCD) and sequential assignment procedures. The fundamental units of the MCD approach, the main-chain NH-C alpha H-C beta H J-coupled subspin systems of each amino acid residue (NAB sets), were defined by analysis of direct and relayed coherence transfer spectra. Recognition of main-chain NOE connectivity patterns specified in the MCD algorithm then allowed NAB sets to be aligned in their proper juxtaposition within secondary structural units. The units of secondary structure were placed within the polypeptide sequence of identification of a small number of side-chain J-coupled spin systems, found by direct recognition in 2D spectra of some J-coupled spin systems and by pairwise comparisons of the J-correlated spectra of six homologous cytochromes c having a small number of known amino acid differences. The placement of a given segment in this way defines the amino acid identity of all its NAB sets. This foreknowledge allowed the vast majority of the side-chain resonances to be discerned in J-correlated spectra. Extensive confirmation of the assignments derives internally from multiple main-chain NOE connectivities and their consistency following temperature-induced changes of the chemical shifts of NOE-correlated protons. The observed patterns of main-chain NOEs provide some structural information and suggest small but potentially significant differences between the solution structure observed by NMR and that defined earlier in crystallographic studies at 2.8-A resolution.