The Protective Role of Non-Photochemical Quenching in PSII Photo-Susceptibility: A Case Study in the Field

Non-photochemical quenching (NPQ) has been regarded as a safety valve to dissipate excess absorbed light energy not used for photochemistry. However, there exists no general consensus on the photoprotective role of NPQ. In the present study, we quantified the Photosystem II (PSII) photo-susceptibilities (mpi) in the presence of lincomycin, under red light given to five shade-acclimated tree species grown in the field. Photosynthetic energy partitioning theory was applied to investigate the relationships between mpi and each of the regulatory light-induced NPQ [Y(NPQ)], the quantum yield of the constitutive nonregulatory NPQ [Y(NO)] and the PSII photochemical yield in the light-adapted state [Y(PSII)] under different red irradiances. It was found that in the low to moderate irradiance range (50-800 μmol m-2 s-1) when the fraction of open reaction centers (qP) exceeded 0.4, mpi exhibited no association with Y(NPQ), Y(NO) and Y(PSII) across species. However, when qP < 0.4 (1,500 μmol m-2 s-1), there existed positive relationships between mpi and Y(NPQ) or Y(NO) but a negative relationship between mpi and Y(PSII). It is postulated that both Y(NPQ) and Y(NO) contain protective and damage components and that using only Y(NPQ) or Y(NO) metrics to identify the photo-susceptibility of a species is a risk. It seems that qP regulates the balance of the two components for each of Y(NPQ) and Y(NO). Under strong irradiance, when both protective Y(NPQ) and Y(NO) are saturated/depressed, the forward electron flow [i.e. Y(PSII)] acts as the last defense to resist photoinhibition.

[Clinical analysis of 81 cases of intravenous leiomyomatosis confined to pelvic cavity]

Objective: To investigate the clinical features, treatment and recurrence factors of intravenous leiomyomatosis (IVL) confined to the pelvic cavity after the operation. Methods: The clinical data of 81 patients who underwent surgery and were pathologically diagnosed with IVL at Women's Hospital, School of Medicine, Zhejiang University from January 2014 to March 2021, were analyzed retrospectively to explore the influencing factors of postoperative recurrence of IVL, including age, gravidity and parity, surgical methods, intraoperative conditions and so on. Results: (1) Clinical features: the age of 81 IVL patients was (43.9±8.1) years old; increased menstrual volume in 26 cases (32%, 26/81), prolonged menstrual period in 31 cases (38%, 31/81), frequency and urgency to urinate in 4 cases (5%, 4/81), abdominal pain and abdominal distension in 8 cases (10%, 8/81), and pelvic masses in 34 cases (42%, 34/81). IVL was diagnosed right in 4 of 72 patients (6%, 4/72) underwent preoperative ultrasound, right in 11 of 51 patients (22%, 11/51) underwent magnetic resonance imaging (MRI), and right in 4 of 19 patients (4/19) underwent CT. (2) Treatment: all patients with IVL underwent surgical treatment. Surgical procedure: myomectomy in 37 cases, total hysterectomy and bilateral salpingectomy in 19 cases, total hysterectomy and bilateral salpingo-ophorectomy in 25 cases. Surgical approach: hysteroscopic operation in 6 cases, transabdominal operation in 52 cases, laparoscopic operation in 23 cases. Fifty-three cases underwent rapid intraoperative pathological examination, 17 cases (32%, 17/53) of them were diagnosed right as IVL. (3) Influencing factors of IVL postoperative recurrence: among 81 patients with IVL, 3 cases were lost to follow-up, and 8 cases (10%, 8/78) had recurrence during follow-up. Age<35 years, number of pregnancies<2, number of births<2, number of fibroids ≥10, abnormal appearance of fibroids (long, vermicular, beadlike, cystic, etc.) and IVL invasion into adjacent vessels were all the risk factors influencing postoperative recurrence of IVL (all P<0.05). Methods of operation, ovariectomy or not, IVL invasion or not, maximum diameter of IVL, abundant blood vessels near uterine fibroids were not associated with postoperative recurrence of IVL (all P>0.05). Conclusions: The clinical manifestations and preoperative auxiliary examination of IVL are lack of specificity. Doctors need to pay attention to young patients with uterine fibroids, and choose the appropriate surgical scope when the characteristic manifestations of IVL be found during the operation, or the right diagnoses of IVL in the surgery's rapid intraoperative pathology be examined, and should remove the IVL lesions to reduce the recurrence as far as possible.

[Growth stability of four drought resistant plant species in different regions]

There are abundant germplasm resources of drought resistant trees in China. It is difficult for foresters to evaluate and screen excellent germplasm that is suitable for various drought adverse circumstances. In this study, four tree species from different provenances, namely Amygdalus davi-diana, Prunus sibirica, Salix gordejevii, and Caryopteris mongolica, were used as test materials. Four soil regions, namely Dalad Banner, Siziwang Banner, Kouhezi town and Liujiazi town of Kulun Banner in the Central and Eastern Inner Mongolia Autonomous Region were selected as multi-point experiment sites to analyze the growth and physiological status of different tree species and provenances. The additive main effects and multiplicative interaction model was used to evaluate the regional adaptability and stability of the germplasm. The growth and physiological indices of four tree species differed between provenances and locations. Soil conditions (potassium content, nitrogen content, and pH) and climate conditions (annual average temperature, precipitation, and potential evaportranspiration) in different locations all influenced the growth of different provenance species. Concerning tree species, S. gordejevii and C. mongolica are more adapted to the sandy loam and chestnut soil of Dalad Banner and Siziwang Banner. A. davidiana and P. sibirica L. are more adapted to the loess and aeolian sandy soil of Kouhezi town and Liujiazi town. Concerning tree provenances, A. davidiana of Tuzuo, P. sibirica of Ningcheng and Yuanzhou, S. gordejevii of Lanqi, and C. mongolica of Jingbian displayed higher regional stability and better growth adaptability, indicating their suitability for afforestation in similar areas.

[Radiographic assessment of vertebral artery injury in anterior cervical surgery in healthy adults]

Objectives: To study the relationship between the anatomical parameters of transverse foramen and intervertebral discs in the cross-section of the cervical spine in healthy adults, and to evaluate the risk of vertebral artery injury in the anterior cervical spine surgery. Methods: There were 24 healthy adults(12 male, 12 female) underwent neck CT angiography with clear vertebral artery and the adjacent structure imaging from June to December 2014 in Huashan Hospital, Fudan University. The anatomical parameters of vertebral artery V2 segment with lower cervical vertebrae and intervertebral discs were measured by cross-sectional images of C(3-6). The corresponding parameters of different sex and both sides of the same segment were analyzed by independent samples t-test and paired t test, respectively. The least significant difference(LSD) t test was used to compare the corresponding data between different segments. Results: The vertebral artery was not walking in the middle of the transverse foramen in healthy individual, but partial medial, partial front walking. Transverse diameter of transverse foramen in male and female were 6.62-6.89 mm and 6.21-6.45 mm, and sagittal diameter was 5.41-6.48 mm and 5.40-6.10 mm, respectively.The transverse foramen were slightly oval. The distance between vertebral artery and midline in male and female were 14.23-16.12 mm and 13.60-15.04 mm, respectively, which was much larger than the width of cervical vertebral corpectomy. Compared with C(3-4), intervertebral disc, the transverse distance between the vertebral artery and the uncovertebral joint of C(4-5), C(5-6) was smaller, and the distance from the vertebral artery to the posterior margin of the uncovertebral joint was relatively small, the difference was statistically significant (t=2.449, P=0.022). The distance from vertebral artery to the posterior margin of uncinate process was 1/5-2/5 of the distance between the anterior and posterior edge of the corresponding segmental vertebra. Conclusion: Based on this anatomical study, the risk of vertebral artery injury in conventional anterior cervical decompression is small, and the risk of vertebral artery injury in different segments is slightly different.

Biological mechanism of post-herpetic neuralgia: Evidence from multiple patho-psychophysiological measures

BACKGROUND

Post-herpetic neuralgia (PHN), which develops after the resolution of a herpes zoster eruption, is an exceptionally drug-resistant neuropathic pain. The unsatisfactory management of PHN partly results from the difficulty in dissecting out its contributing factors due to the complexity of PHN mechanism.

METHODS

Here, to elaborate our understanding of the PHN mechanism and to establish a basis for effective therapeutic strategies, we comprehensively investigated the contributions of multiple factors to PHN severity.

RESULTS

Based on the comparison of somatosensory detection thresholds (C, Aδ and Aβ fibre thresholds) between affected and unaffected sides, 16 PHN patients with significant sensory deficits and 13 PHN patients without significant sensory deficits were identified and assigned to different groups. The different extents of lesions in the nociceptive system between patients with and without sensory deficits were confirmed using laser-evoked brain responses. Moreover, patients with sensory deficits had more severe pain and psychological disorders, e.g. anxiety and depression. Importantly, chronic pain severity was significantly influenced by various psychophysiological factors (sleep disturbances, psychological disorders and hypothalamic-pituitary-adrenal axis dysfunction) for patients with sensory deficits.

CONCLUSIONS

Our findings demonstrated the contribution of multiple patho-psychophysiological factors to PHN severity, which could help establish a basis for the development of a rational, patient-centred therapeutic strategy.

SIGNIFICANCE

This study revealed the contribution of multiple patho-psychophysiological factors to PHN severity, which expanded our understanding of the underlying PHN mechanism, and helped develop a rational, patient-centred therapeutic strategy targeting towards the corresponding etiology and psychophysiological disorders for individual patient.

Salicylic acid-induced changes in physiological parameters and genes of the flavonoid biosynthesis pathway in Artemisia vulgaris and Dendranthema nankingense during aphid feeding

Phloem-feeding aphids cause serious damage to plants. The mechanisms of plant-aphid interactions are only partially understood and involve multiple pathways, including phytohormones. In order to investigate whether salicylic acid (SA) is involved and how it plays a part in the defense response to the aphid Macrosiphoniella sanbourni, physiological changes and gene expression profiles in response to aphid inoculation with or without SA pretreatment were compared between the aphid-resistant Artemisia vulgaris 'Variegata' and the susceptible chrysanthemum, Dendranthema nankingense. Changes in levels of reactive oxygen species, malondialdehyde (MDA), and flavonoids, and in the expression of genes involved in flavonoid biosynthesis, including PAL (phenylalanine ammonia-lyase), CHS (chalcone synthase), CHI (chalcone isomerase), F3H (flavanone 3-hydroxylase), F3'H (flavanone 3'-hydroxylase), and DFR (dihydroflavonol reductase), were investigated. Levels of hydrogen peroxide, superoxide anions, MDA, and flavonoids, and their related gene expression, increased after aphid infestation and SA pretreatment followed by aphid infestation; the aphid-resistant A. vulgaris exhibited a more rapid response than the aphid-susceptible D. nankingense to SA treatment and aphid infestation. Taken together, our results suggest that SA could be used to increase aphid resistance in the chrysanthemum.

XsFAD2 gene encodes the enzyme responsible for the high linoleic acid content in oil accumulated in Xanthoceras sorbifolia seeds

BACKGROUND

Xanthoceras sorbifolia Bunge is a valuable oilseed tree that has linoleic acid-rich seed oil. Microsomal oleate desaturase (FAD2; EC 1.3.1.35) is responsible for the conversion of oleic acid to linoleic acid during fatty acid synthesis. In this study, XsFAD2 was cloned from developing embryos of X. sorbifolia.

RESULTS

XsFAD2 contained three histidine boxes, a C-terminal endoplasmic reticulum retrieval motif, and five putative transmembrane domains representing the characteristics of membrane-bound fatty acid desaturase. XsFAD2 expression in yeast cells resulted in linoleic acid (18:2) and palmitolinoleic acid (16:2) production, confirming the biological activity of the enzyme encoded by XsFAD2. These fatty acids are not normally present in wild-type yeast. Phylogenetic analysis indicated that XsFAD2 is located in a subgroup of FAD2 enzymes specifically or highly expressed in developing seeds. The expression level of XsFAD2 in seeds was much higher than those in leaves and petals. Furthermore, XsFAD2 expression pattern correlated well with linoleic acid accumulated in seeds.

CONCLUSION

Results suggested that XsFAD2 is responsible for the high linoleic acid content in X. sorbifolia seed oil. This study provides insight on the regulation mechanism of fatty acid synthesis in X. sorbifolia seeds and a valuable gene for improving the oil quality in oilseed trees.

Overexpression of the poplar NF-YB7 transcription factor confers drought tolerance and improves water-use efficiency in Arabidopsis

Water deficit is a serious environmental factor limiting the growth and productivity of plants worldwide. Improvement of drought tolerance and efficient water use are significant strategies to overcome this dilemma. In this study, a drought-responsive transcription factor, nuclear factor Y subunit B 7 (PdNF-YB7), induced by osmotic stress (PEG6000) and abscisic acid, was isolated from fast-growing poplar clone NE-19 [Populus nigra × (Populus deltoides × Populus nigra)]. Ectopic overexpression of PdNF-YB7 (oxPdB7) in Arabidopsis enhanced drought tolerance and whole-plant and instantaneous leaf water-use efficiency (WUE, the ratio of biomass produced to water consumed). Overexpressing lines had an increase in germination rate and root length and decrease in water loss and displayed higher photosynthetic rate, instantaneous leaf WUE, and leaf water potential to exhibit enhanced drought tolerance under water scarcity. Additionally, overexpression of PdNF-YB7 in Arabidopsis improved whole-plant WUE by increasing carbon assimilation and reducing transpiration with water abundance. These drought-tolerant, higher WUE transgenic Arabidopsis had earlier seedling establishment and higher biomass than controls under normal and drought conditions. In contrast, Arabidopsis mutant nf-yb3 was more sensitive to drought stress with lower WUE. However, complementation analysis indicated that complementary lines (nf-yb3/PdB7) had almost the same drought response and WUE as wild-type Col-0. Taken together, these results suggest that PdNF-YB7 positively confers drought tolerance and improves WUE in Arabidopsis; thus it could potentially be used in breeding drought-tolerant plants with increased production even under water deficiency.

The salt- and drought-inducible poplar GRAS protein SCL7 confers salt and drought tolerance in Arabidopsis thaliana

The plant-specific GRAS/SCL transcription factors play diverse roles in plant development and stress responses. In this study, a poplar SCL gene, PeSCL7, was functionally characterized in Arabidopsis thaliana, especially with regard to its role in abiotic stress resistance. Expression analysis in poplar revealed that PeSCL7 was induced by drought and high salt stresses, but was repressed by gibberellic acid (GA) treatment in leaves. Transient expression of GFP-PeSCL7 in onion epidermal cells revealed that the PeSCL7 protein was localized in the nucleus. Transgenic Arabidopsis plants overexpressing PeSCL7 showed enhanced tolerance to drought and salt treatments. The activity of two stress-responsive enzymes was increased in transgenic seedlings. Taken together, these results suggest that PeSCL7 encodes a member of the stress-responsive GRAS/SCL transcription factors that is potentially useful for engineering drought- and salt-tolerant trees.

Molecular characterization of putative vacuolar NHX-type Na(+)/H(+) exchanger genes from the salt-resistant tree Populus euphratica

The vacuolar NHX-type Na(+)/H(+) exchangers play a key role in salt tolerance in plants. However, little is known about the Na(+)/H(+) exchangers in the salt-resistant tree, Populus euphratica. In this study, we identified six putative vacuolar Na(+)/H(+) exchanger genes from P. euphratica, designated as PeNHX1-6. Real-time polymerase chain reaction indicated that the PeNHX1/3/6 transcripts were abundant compared with the other three PeNHX genes in the three tissues (roots, stems and leaves) examined. After NaCl treatment for 6 h, the transcript levels of PeNHX1-6 were upregulated in the roots. To address the function of PeNHX1-6, complementation studies were performed with the salt-sensitive yeast mutant strain R100, which lacks activity of the endosomal Na(+)/H(+) antiporter NHX1. The results showed that PeNHX1-6 compensates, at least in part, for the function of yeast NHX1. Moreover, PeNHX3 was targeted to the tonoplast when transiently expressed in onion. Together, these results suggest that PeNHX1-6 function as vacuolar Na(+)/H(+) exchangers and that PeNHX products play an important role in the salt resistance of P. euphratica.

Stress responsive zinc-finger protein gene of Populus euphratica in tobacco enhances salt tolerance

The Populus euphratica stress responsive zinc-finger protein gene PSTZ, which encodes a protein including typical Cys(2)/His(2) zinc finger structure, was isolated by reverse transcription-polymerase chain reaction from P. euphratica. Northern hybridization revealed that its expression was induced under drought and salt stress conditions. To examine its function, cDNA of the PSTZ gene, driven by the cauliflower mosaic virus 35S promoter, was cloned into a plant expression vector pBin438 and introduced into tobacco plants. Transgenic tobacco showed an enhanced salt tolerance, suggesting that PSTZ may play a role in plant responsiveness to salt stress.

Photo-responsive properties of azobenzene small molecules in sol-gel hybrid TiO(2)/ormosil organic-inorganic matrices

Azodye-doped TiO(2)/ormosil hybrid materials for photonic applications were prepared by a low temperature sol-gel process from an organic-inorganic hybrid system. Acid-catalyzed solutions of gamma-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane mixed with tetrapropyl orthotitanate were used as hybrid matrix precursors. The trans-cis-trans photoisomerization of azobenzene small molecules in sol-gel hybrid organic-inorganic matrices was induced by a photoirradiation with UV light and subsequent visible light. It was found that the hybrid film doped with azodyes and heated at a lower temperature was much better for applications in optical storage or optical switch. The planar waveguide properties of the hybrid films were also investigated by using a prism coupling technique. These results indicates that it is possible for the as prepared hybrid films to allow directly integrating on the same chip the optical storage or optical switch devices with the pump source.

A two year family based behaviour treatment for obese children

BACKGROUND

Childhood obesity has become a nutritional problem in China since the 1990s.

AIMS

A family based behavioural treatment was developed and tested, to see if its use was feasible in China and to evaluate its impact on obese schoolchildren.

METHODS

In a single school in Beijing, 33 obese children were randomly assigned to a treatment group and 35 to a control group. The treatment group participated in a family based behavioural treatment programme for two years. Height and weight were measured every six months for all participants. Blood pressure, cholesterol, and triglyceride levels were measured at baseline and after two years of programme implementation.

RESULTS

Body mass index (BMI, kg/m2) was significantly reduced in the treatment group (from 26.6 (1.7) to 24.0 (0.9), 95% CI 2.06 to 3.18) but not in the control group (from 26.1 (1.5) to 26.0 (1.6)). Total cholesterol decreased 5.5% and triglycerides 9.7% in the treatment group. There was a significant correlation between change in BMI and change in triglycerides. There were no significant changes in plasma lipids in the controls. Blood pressure values also decreased significantly in the treatment, but not the control group.

CONCLUSIONS

A family based behavioural intervention was feasible to use in treating obesity in schoolchildren in Beijing, China. After two years of implementation, it successfully decreased the degree of obesity, reduced levels of blood pressure, and decreased serum lipids in treatment; there were no significant changes among control children.

[Cloning and structure analysis of zinc finger protein gene in Populus euphratica Oliv]

Zinc finger proteins belong to a family of nuclear transcription factors which function is to regulate gene expression in both prokaryotic and eukaryotic cells. A pair of primers was designed after analyzing the conservation of salt-tolerant zinc protein Alfin-1 in such diverse plants as alfalfa and Arabidopsis. The zinc finger protein gene is isolated from total RNA with RT-PCR in aquaculture leaves of Populus euphratica . Its full cDNA length is 924bp. Analysis of its amino acid sequence showed it has a typical Cys(2)/His(2) zinc finger structure and a G-rich promoter binding site GTGGGG, starting from position 556. Since transcrptional factors which have the same function show conservation in structure and amino acid sequence of DNA binding region, the structure analysis in this paper indicates the cloned zinc finger protein gene may have functional correlation to Alfin-1.

PLA2-independent induction of CSF-1 gene expression in growth-arrested fibroblasts

At the site of a wound or an infection, localized production of colony-stimulating factor-1 (CSF-1) by resident macrophages is chemotactic for circulating monocytes. Several intracellular signaling pathways, including those initiated in response to activation of phospholipase A2 (PLA2) have been proposed to play a role in the regulation of CSF-1 gene expression. The goal of these studies was to determine whether PLA2 is required for the initial increase in CSF-1 gene expression in serum- or IL-1 alpha-stimulated growth-arrested fibroblasts. IL-1 alpha- or serum-stimulation of growth-arrested fibroblasts had no effect on PLA2 enzyme activity and inhibitors of cytosolic or Ca(2+)-independent PLA2 activity had no effect on IL-1 alpha- or serum-mediated increases in CSF-1 mRNA levels. High concentrations of the PLA2 inhibitors, 4-bromophenacyl lactone and quinacrine, resulted in a generalized decrease in cellular mRNA levels. Our results, obtained in fibroblasts, suggest treatment with 4-bromophenacyl lactone or quinacrine, instead of inhibiting PLA2 activity specifically, results in a generalized depression of cellular mRNA levels. These data demonstrate that the initial increase in CSF-1 gene expression in growth-arrested fibroblasts treated with serum or IL-1 alpha occurs through a PLA2-independent mechanism.

Transcriptional regulation of the mouse CSF-1 gene

Research in our laboratory is aimed at understanding the cellular and molecular mechanisms that govern colony stimulating factor-1 (CSF-1) gene expression. Our hypothesis is that a basal set of trans-acting factors is bound to the CSF-1 gene during fibroblast proliferation, resulting in constitutive CSF-1 gene expression. Modulation of CSF-1 gene transcription by growth-arrest (decrease) or stimulation of growth-arrested fibroblasts (re-initiate) is mediated by changes in the basal set of factors bound and/or by the addition of stimulus-specific factors. We have extended our hypothesis to include other cell types (monocytes) to determine if mechanisms used to control CSF-1 gene expression in fibroblasts are unique or represent common nontissue-specific regulatory mechanisms. Analysis of CSF-1-CAT reporter constructs in transiently transfected fibroblasts and monocytes was used to identify CSF-1 genomic sequences that affect transcriptional activity. DNase I protection, electrophoretic mobility shift, and methylation interference assays were used to identify the putative cis-acting elements. Results of our study suggest multiple trans-acting factors may regulate CSF-1 gene expression; some may be tissue specific, while others, such as AP1, CTF/NF1, Sp1, and Sp3, are shared in common.

Binding of a CTF/NF1-like protein to the mouse colony-stimulating factor-1 gene promoter

Circulating and tissue-specific monocytes/macrophages, through production of hydrolytic enzymes and growth factors, can dramatically affect the local tissue environment. Colony-stimulating factor-1 (CSF-1) is a key regulator of monocyte/macrophage cell activity. CSF-1 is produced by stromal elements, including fibroblasts, which are found in all tissues. To understand at the molecular level how changes in CSF-1 gene transcription are initiated in fibroblasts, we set out to identify the cis-acting elements and cognate trans-acting factor(s) that bind regulatory regions of the mouse CSF-1 gene. Analysis of heterologous reporter constructs containing the mouse CSF-1 promoter linked to the bacterial chloramphenicol acetyltransferase (CAT) gene in transiently transfected fibroblasts identified a cis-acting element located between base pairs -88 and -43 of the CSF-1 gene. Electrophoretic mobility-shift assays (EMSAs) and DNase I protection assays with nuclear extracts isolated from proliferating fibroblasts revealed distinct protein binding to the region spanning base pairs -90 to -68. Results from methylation interference assays suggest CTF/NF1 or a CTF/NF1-like factor is the cognate trans-acting factor. Mutation of the putative CTF/NF1 binding site in the CSF-1 promoter lead to a modest decrease in promoter activity in transiently transfected fibroblasts and monocytes. Therefore, we have demonstrated that CTF/NF1 or a CTF/NF1-like protein binds to the CSF-1 gene promoter; however, binding of the CTF/NF1-like protein alone does not significantly effect changes in CSF-1 gene promoter activity.

Susceptibility to hepatocellular carcinoma is associated with genetic variation in the enzymatic detoxification of aflatoxin B1

Aflatoxin B1 (AFB1) has been postulated to be a hepatocarcinogen in humans, possibly by causing p53 mutations at codon 249. AFB1 is metabolized via the phase I and II detoxification pathways; hence, genetic variation at those loci may predict susceptibility to the effects of AFB1. To test this hypothesis, genetic variation in two AFB1 detoxification genes, epoxide hydrolase (EPHX) and glutathione S-transferase M1 (GSTM1), was contrasted with the presence of serum AFB1-albumin adducts, the presence of hepatocellular carcinoma (HCC), and with p53 codon 249 mutations. Mutant alleles at both loci were significantly overrepresented in individuals with serum AFB1-albumin adducts in a cross-sectional study. Mutant alleles of EPHX were significantly overrepresented in persons with HCC, also in a case-control study. The relationship of EPHX to HCC varied by hepatitis B surface antigen status and indicated that a synergistic effect may exist. p53 codon 249 mutations were observed only among HCC patients with one or both high-risk genotypes. These results indicate that individuals with mutant genotypes at EPHX and GSTM1 may be at greater risk of developing AFB1 adducts, p53 mutations, and HCC when exposed to AFB1. Hepatitis B carriers with the high-risk genotypes may be an even greater risk than carriers with low-risk genotypes. These findings support the existence of genetic susceptibility in humans to the environmental carcinogen AFB1 and indicate that there is a synergistic increase in risk of HCC with the combination of hepatitis B virus infection and susceptible genotype.

Inhibition of colony-stimulating factor-1 promoter activity by the product of the Wilms' tumor locus

Colony-stimulating factor-1 (CSF-1) is a member of the immediate early gene family, which is expressed in mitogen-stimulated quiescent fibroblasts. The biological effects of CSF-1 are multifaceted and include stimulation of the proliferation and differentiation of myeloid progenitors and activity of circulating monocytes and tissue-specific macrophages. Ablation of circulating levels of biologically active CSF-1 in mice leads to osteopetrosis and sterility, thus implicating a role for CSF-1 in bone remodeling and implantation. Identification of regulatory elements and cognate transcription factors that bind the csf-1 promoter and mediate such diverse expression patterns is of great interest. We identified a sequence element at -273 to -265 (relative to the transcription initiation site) in the murine csf-1 promoter, which contains overlapping consensus sequences for the Wilms' tumor protein (WT1), EGR-1, SP1, and SP3 proteins. WT1 and EGR-1 proteins produced in vitro bound to this sequence, and co-transfection of wt1 with a csf-1-cat reporter plasmid resulted in repression of promoter activity. Interestingly, nuclear extracts prepared from serum-stimulated C3H10T1/2 cells contained predominantly SP1 and SP3 binding activities, which recognized the -273 to -265 site. Thus repression of the csf-1 promoter by WT1 at this site may involve competition between SP1 family transcriptional activators and the WT1 repressor. Colony-stimulating factor-1 may be a physiologically relevant target gene for regulation by the WT1 transcription factor.

[Aggressive fibromatosis of bone]

Twenty four cases of pathologically diagnosed aggressive fibromatosis of bone were reported. 17 patients were followed for at least 2 years. Among them 4 recurred and the histological findings of their lesional tissues obtained after recurrence remained benign; one case refused radical treatment and the second biopsy done at 3.5 years after the appearance of the tumor showed no malignant changes; but another case died of lung metastasis. The authors suggest that the criteria for final diagnosis of an aggressive fibromatosis of bone are as follows: Besides the pathological findings, the lesion does not recur or metastasize more than 2 years after operation or it does recur, but still shows benign features histologically. As for treatment, marginal or wide excision is the procedure of choice.

[Diagnosis and treatment of secondary bone cysts]

The article reported 17 cases of confirmed or suspected secondary bone cyst originating from cystic degeneration of pre-existed tumor or tumor-like lesions. Twelve cases were diagnosed as solitary bone cysts pathologically after operation, but their clinical or radiological manifestations were not in keeping with the pathological findings. Among them aggressive or malignant tumors appeared in 6 cases during follow-up and no primary lesions could be found in other 6 cases. The macroscopic features of the lesion of other 5 cases were very similar to a solitary bone cyst, nevertheless, primary tumors were found histologically. The authors held that when dealing with a cystic lesion of bone, it was important, but sometimes difficult to differentiate a solitary bone cyst from a secondary one, and suggested that if the latter was suspected, injection therapy should not be used, but more radical procedures should be taken for treatment instead and the patient should be observed closely for a longer period.

Studies on synthesis and relationship between analgesic activity and receptor affinity for 3-methyl fentanyl derivatives

In the present paper, the synthesis and analgesic activity (mice, i.p. hot plate test) of the derivatives of 3-methyl fentanyl are briefly described. Compound 7302, cis-N-[1-(2-hydroxy-2-phenylethyl)-3-methyl-4-piperidyl]-N-phenylpropionamide (cis: 3-methyl/4-N-phenylpropionamide) is found to be the most potent analgesic agent in this series synthesized by our laboratory (ED50 = 0.0022 mg/kg). The analgesic activity of 7302 is 28 times more potent than that of fentanyl and 6300 times more than that of morphine. The partition coefficients of 10 compounds in the series are determined by high performance liquid chromatography (HPLC) and their log p values are about 3. There are no regular relationships between the analgesic activity and partition coefficients. Study on the specific binding of 8 out of the above 10 compounds to crude synaptic plasma membrane (P2-fraction) of mouse brain demonstrates that there is an excellent statistical linear correlation (r = 0.998) between the analgesic potency and the specific binding affinity. The result shows that the analgesic potency of the derivatives of this series is mainly dependent on binding affinity for opiate receptor.