Baicalin administration could rescue high glucose-induced craniofacial skeleton malformation by regulating neural crest development

Hyperglycemia in pregnancy can increase the risk of congenital disorders, but little is known about craniofacial skeleton malformation and its corresponding medication. Our study first used meta-analysis to review the previous findings. Second, baicalin, an antioxidant, was chosen to counteract high glucose-induced craniofacial skeleton malformation. Its effectiveness was then tested by exposing chicken embryos to a combination of high glucose (HG, 50 mM) and 6 μM baicalin. Third, whole-mount immunofluorescence staining and in situ hybridization revealed that baicalin administration could reverse HG-inhibited neural crest cells (NCC) delamination and migration through upregulating the expression of Pax7 and Foxd3, and mitigate the disordered epithelial-mesenchymal transition (EMT) process by regulating corresponding adhesion molecules and transcription factors (i.e., E-cadherin, N-cadherin, Cadherin 6B, Slug and Msx1). Finally, through bioinformatic analysis and cellular thermal shift assay, we identified the AKR1B1 gene as a potential target. In summary, these findings suggest that baicalin could be used as a therapeutic agent for high glucose-induced craniofacial skeleton malformation.

[Association of extranodal extension and lymph node ratio with radioactive iodine-refractory papillary thyroid cancer]

Objective: To investigate the related factors of radioiodine-refractory thyroid cancer (RAIR-DTC) and the increase of cumulative iodine treatment dose. Methods: The data of patients with papillary thyroid cancer who underwent surgery and iodine treatment for the first time in the Affiliated Cancer Hospital of Zhengzhou University from January 2015 to December 2017 were retrospectively analyzed. The related factors of RAIR-DTC and the increase of cumulative iodine treatment dose were explored. Results: A total of 650 patients were enrolled, including 217 males (33.4%) and 433 females (66.6%), aged 45 (34, 53) years. There were 123 patients (18.9%) over 55 years old, 171 patients (26.3%) with extranodal extension and 18 patients (2.8%) with distant metastasis. The median lymph node ratio was 0.22 (0.11, 0.33). Twenty patients (3.1%) had an accumulated iodine treatment dose>400 mCi and 19 patients (2.9%) had RAIR-DTC. Multivariate logistic regression analysis showed that extranodal extension (OR=19.833, 95%CI: 6.057-73.325, P<0.001) was related factors for the increase of cumulative iodine treatment dose. Age>55 years old (OR=3.322, 95%CI: 1.136-9.466, P=0.024), distant metastasis (OR=10.059, 95%CI: 2.508-38.888, P<0.001), extranodal extension (OR=5.278, 95%CI: 1.707-19.813, P=0.006) and lymph node ratio (OR=34.724, 95%CI: 2.749-384.575, P=0.004) were related factors for RAIR-DTC. Conclusions: Extranodal extension and lymph node ratio are related factors for RAIR-DTC. In clinical practice, more attention should be paid to the influence of different lymph node metastasis characteristics on the occurrence of RAIR-DTC and the cumulative therapeutic dose of iodine.

PBL teaching in ultrasonography resident standardization training in the COVID-19 pandemic

OBJECTIVE

To study the effect of the problem-based learning (PBL) method in ultrasonography (US) resident standardization training during the COVID-19 pandemic.

METHODS

Fifty residents were divided into two groups to participate in a 30-day US training program. The residents in the observation group underwent PBL combined with the lecture-based learning (LBL) method, while the residents in the control group experienced the LBL method alone, with 25 residents in each group. A basic theoretical test, practical examination, and questionnaire were used to evaluate the teaching effect of the PBL + LBL method and the LBL method alone.

RESULTS

The basic theoretical pretest score of the observation group was not significantly different from that of the control group. However, the posttest theoretical score and practical score were significantly higher in the observation group than in the control group (P < 0.01). The results of the questionnaire showed that the resident satisfaction level in the observation group with PBL combined with the LBL method was 96%, which was significantly higher than that of the control group with the LBL method alone (80%) (P < 0.05).

CONCLUSION

The combination of PBL with the LBL method has obvious advantages over the LBL method alone in regard to the training of US residents during the COVID-19 pandemic.

Effect of different types of sugar on gut physiology and microbiota in overfed goose

To explored the difference of goose fatty liver formation induced-by different types of sugar from the intestinal physiology and the gut microflora, an integrated analysis of intestinal physiology and gut microbiota metagenomes was performed using samples collected from the geese including the normal-feeding geese and the overfed geese which were overfed with maize flour or overfeeding dietary supplementation with 10% sugar (glucose, fructose or sucrose, respectively), respectively. The results showed that the foie gras weight of the fructose group and the sucrose group was heavier (P < 0.05) than other groups. Compared with the control group, the ileum weight was significantly higher (P < 0.01), and the cecum weight was significantly lower in the sugar treatment groups (P < 0.001). Compared with the control group, the ratio of villi height to crypt depth in the fructose group was the highest in jejunum (P < 0.05); the trypsin activity of the ileum was higher in the fructose group and the sucrose group (P < 0.05). At the phylum level, Firmicutes, Proteobacteria and Bacteroidetes were the main intestinal flora of geese; and the abundance of Firmicutes in the jejunum was higher in the sugar treatment groups than that of the maize flour group. At the genus level, the abundance of Lactobacillus in the jejunum was higher (P < 0.05) in the sugar treatment groups than that of the maize flour group. In conclusion, forced-feeding diet supplementation with sugar induced stronger digestion and absorption capacity, increased the abundance of Firmicutes and Bacteroidetes and the abundance of Lactobacillus (especially fructose and sucrose) in the gut. So, the fructose and sucrose had higher induction on hepatic steatosis in goose fatty liver formation.

Utility of quantitative contrast-enhanced ultrasound for the prediction of lymph node metastasis in patients with papillary thyroid carcinoma

OBJECTIVES

The aim of this study was to find the optimal parameters and cutoffs to differentiate metastatic lymph nodes (LNs) from benign LNs in the patients with papillary thyroid carcinoma (PTC) on the quantitative contrast-enhanced ultrasound (CEUS) features.

METHODS

A total of 134 LNs in 105 patients with PTCs were retrospectively enrolled. All LNs were evaluated by conventional ultrasound (US) and CEUS before biopsy or surgery. The diagnostic efficacy of CEUS parameters was analyzed.

RESULTS

Univariate analysis indicated that metastatic LNs more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, ring-enhancing margins, higher PI, larger AUC, longer TTP and DT/2 than benign LNs at pre-operative CEUS (p <  0.001, for all). Multivariate analysis showed that centripetal or asynchronous perfusion (OR = 3.163; 95% CI, 1.721-5.812), hyper-enhancement(OR = 0.371; 95% CI, 0.150-0.917), DT/2 (OR = 7.408; 95% confidence interval CI, 1.496-36.673), and AUC (OR = 8.340; 95% CI, 2.677-25.984) were predictive for the presence of metastatic LNs. The sensitivity and accuracy of the quantitative CEUS were higher than qualitative CEUS (75% vs 55 % and 83.6% vs 76.1 % , respectively).

CONCLUSIONS

Quantitative CEUS parameters can provide more information to distinguish metastatic from benign LNs in PTC patients; In particular, DT/2 and AUC have a higher sensitivity and accuracy in predicting the presence of metastatic LNs and reduce unnecessary sampling of benign LNs.

Role of Contrast-Enhanced Ultrasound in the Pre-operative Diagnosis of Cervical Lymph Node Metastasis in Patients with Papillary Thyroid Carcinoma

The objective of this study was to prospectively evaluate the diagnostic accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating between benign and metastatic cervical lymph nodes in patients with papillary thyroid cancer (PTC). Three hundred nineteen cervical lymph nodes (162 metastatic from PTC and 157 benign) were evaluated using conventional ultrasonography (US) and CEUS before biopsy or surgery. Metastatic lymph nodes more often manifested centripetal or asynchronous perfusion, hyper-enhancement, heterogeneous enhancement, perfusion defects and ring-enhancing margins than benign lymph nodes at pre-operative CEUS (all p values < 0.001). The area under the receiver operating characteristic curve (AUC) for the combination of conventional US and CEUS (0.983, 95% confidence interval [CI]: 0.971-0.994) was higher than that of conventional US alone (0.929, 95% CI: 0.899-0.958) and CEUS (0.911, 95% CI: 0.876-0.947). In conclusion, CEUS is a promising tool in conjunction with conventional US for the pre-operative prediction of metastatic cervical lymph nodes in patients with PTC.

Effect of gene polymorphims on the warfarin treatment at initial stage

The adverse reactions of warfarin that were found mainly occurred in the first month. This study was carried out to observe the effect of gene polymorphisms on the warfarin therapy at the initial stage. Four-hundred and sixty Chinese patients began warfarin treatment with daily 2.5 mg after heart valve replacement operations were enrolled. The daily international normalized ratio (INR) for anticoagulation were recorded till the seventh day. Blood samples were collected and used to detect genotypes for VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650. INR and their changes were compared among genotypes. INR was partially correlated with the VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 polymorphisms from the third, fourth and sixth day on, respectively. VKORC1 rs7294 and CYP4F2 rs2108622 carriers responded lower than the wild genotype, whereas CYP2C9 rs1057910 and ORM1 rs17650 carriers responded higher, respectively. Fifty percent of AA/*1*3/CC/*S*S patients and 16% of AA/*1*1/CC/*S*S patients were over anticoagulation treated with INR >4.0 at the third day. Ninety percent of VKORC1 rs7294 carrier patients have INR <1.63, a mark of the 25% of lower responders of the wild genotype. Our study provided another kind of evidence that VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 affected the action of warfarin in different styles. Patients with AA/*1*1/CC/*S*S, AA/*1*3/CC/*S*S should use a less initial dosage to avoid over anticoagulation, and patients with VKORC1 rs7294 should use larger initial dose to proof an effective therapy.

Conventional US, elastography, and contrast enhanced US features of papillary thyroid microcarcinoma predict central compartment lymph node metastases

Lymph node metastases at the time of diagnosis have a major impact on both therapeutic strategy and tumor recurrence for patients with papillary thyroid microcarcinoma (PTMC). Our objective was to evaluate the usefulness of PTMC characteristics on ultrasonography for predicting central compartment lymph node metastases (CCLNM) of PTMC. One hundred twenty seven patients who underwent surgery for PTMC were enrolled in this study. The relationship between the CCLNM and the characteristics on conventional US, elastographic, and contrast enhanced ultrasound (CEUS) were investigated. Univariate analysis indicated that PTMCs with CCLNM were more often nodule irregular shape, microcalcifications, hyperenhancing or isoenhancing parametric maps, and peak index ≥1 at preoperative US and CEUS than those without CCLNM (P< 0.01, 0.05, 0.01 and 0.05 respectively). Multivariate analysis showed that microcalcification (OR:2.378, 95% CI: 1.096–5.158) and hyperenhancement or isoenhancement (OR:2.8, 95% CI: 1.287–6.094) were predictive for the presence of CCLNM. Elastography score was not significantly different between the groups. Our study indicated that preoperative thyroid nodule characteristics on conventional US and CEUS may serve as a useful tool to predict central compartment lymph node metastases in PTMC.

[Diagnostic value of lesion-directed prostate biopsy under TRUS in early detection of prostate cancer]

OBJECTIVE

To evaluate lesion-directed biopsy in improving the detection rate of early prostate cancer (PCa) and in differentiating PCa from other prostate pathological changes.

METHODS

We performed TRUS-guided prostate biopsy for 95 patients suspected of PCa, each subjected to extended random biopsy plus lesion-directed biopsy, and analyzed the sonographic characteristics and pathological findings.

RESULTS

PCa was detected in 35 of the patients (36.8%), including 16 hypoechoic (45.7%), 4 hyperechoic (11.4%), 10 isoechoic (28.6%) and 5 mixed hetero-echoic lesions (14.3%). Of the 35 PCa cases, 17 (46.2%) were within T2b, 70.6% (12/17) of which were detected by lesion-directed biopsy and 29.4% (5/17) by sextant biopsy, the former obviously higher than the latter (P < 0.05).

CONCLUSION

Lesion-directed prostate biopsy under TRUS can significantly improve the early diagnosis of prostate cancer, increase convenience and reduce patients' pain, but is not sufficient to replace traditional sextant biopsy.

Investigation of serum protein systems in Chinese pigs

Polymorphisms of transferrin (Tf), pre-albumin (Pa), haemopexin (Hpx), ceruloplasmin (Cp) and amylase (Am) of Duroc pigs and Hunan indigenous pigs were investigated using horizontal starch gel electrophoresis. Allele frequencies of Durocs determined in 2004 were compared with frequencies presented in the paper by Baker L.N. (1968) Serum protein variation in Duroc and Hampshire pigs. Vox Sanguinis15, 154-8. The number of serum protein alleles decreased over time and allele frequencies aggregated across certain alleles, including TfB, PaA, Hpx3, CpB and AmB. Differences in allele frequencies, average heterozygosities and standard genetic distances between the Duroc pigs and Hunan indigenous pig populations were examined. The relationship between Durocs and Hunan indigenous pigs was found to be more distant than those among the three Hunan indigenous pig populations.

[Cloning and efficient expression of cytokine human MK in E. coli]

For cloning the cytokine human Midkine (MK) gene, we designed by PCgene program and synthesized a pair of PCR specific primers according to the reported human MK cDNA sequence. Total cellular RNA was extracted from a human hepatoblastoma cell line HepG2, and then the target DNA fragment was obtained by RT-PCR and subcloned into plasmid pUC118. Checked with radioisotope sequencing and ABI 377A sequencer, the nucleotide sequence of the cloned MK cDNA was identical with the reported one. A prokaryotic expression vector, named pBV220, was used to express the MK protein efficiently in E. coli strain TG1 and a predicted band of 16.5 kD in Mr by 15% SDS-PAGE was found. The expressed recombinant protein was found in insoluble aggregated form and accounted for about 31.21% of the total cellular proteins. The first 15 N-terminal amino acid sequence analysis of this protein by Edman degradation method showed that it was accordant with that predicted from the cDNA sequence. The activity of neurite outgrowth-promoting of the MK crude samples was tested with brain cells isolated from 18-day embryos of SD rat.

[Isolation of high-quality genomic DNA from plants]

In order to isolate high-quality genomic DNA from medicinal plant tissues enriching polyphenols and polysaccharides, a simple and rapid method based on CTAB extraction for isolating high-quality intact DNA was established by modifying several existing methods. With this technique, the absorbance ratio (A260/A280) of DNAs obtained from fresh and/or dried roots of Panax ginseng, P. Quinquefolius and P. notoginseng was 1.8 approximately. The restriction fragments of DNAs were directly digested with restriction enzyme (EcoR I/Mse I), linked up by T4 DNA ligase and amplified by nested PCR. Reproducible amplified fragment length polymorphism (AFLP) genomic DNA fingerprinting profiles were established with the isolated DNAs. The results demonstrate that the modified technique may be efficient and reliable in isolating high-quality and high-molecular-weight DNAs from fresh and/or dried medicinal plants containing a high content of polyphenols and polysaccharides. We expect that this method can also be applied to other plants.

[The anti-leukemia effect of Sophora flavescens and its mechanism]

By using CFU-GM/CFU-L colony assay, NBT/MTT reductant test and DNA fragmentation analysis, we studied the effects of Sophora flavescens (SF) on CFU-GM proliferative ratio in human normal bone marrow/umbilical cord blood and on proliferation, differentiation and apoptosis in human acute myelogenous leukemia HL-60 cells. The results showed that 5, 10, 15, 20 micrograms.microliter-1 of SF significantly inhibited proliferation and induced apoptosis in the HL-60 cells in a dose-dependent fashion. Fifteen micrograms.microliter-1 of SF also induced differentiation in HL-60 cells. Furthermore, cytotoxic activity of SF(5-15 micrograms.microliter-1) was not apparent on human normal hematopoietic progenitors(CFU-GM). The results indicate that an appropriate concentration of SF has a selective antileukemic effect. Thus, these are important impetuses for further research of SF as an anticancer agent.

[The mechanism of macrophage apoptosis induced by lipopolysaccharide in mice]

Apoptosis is a major form of cell death, characterized morphologically by chromatin condensation and biochemically by endonuclease cleavage of DNA into oligonucleosomal fragments. We investigated apoptosis mechanism of peritoneal macrophage(M phi) induced by peritoneal injection of lipopolysaccharide(LPS) in mice. The results showed that: LPS induced the apoptosis of peritoneal M phi and concomitant decrease of phagocytosis(vs control group, P < 0.01), the concentration of NO2-/No3- in the peritoneal lavage fluid significantly increased after LPS injection; AG(inhibitor of iNOS) and PDTC(inhibitor of reactive oxygen species) prevented the apoptosis of M phi and reduced the concentration of NO2-/NO3- in the peritoneal lavage fluid. In vitro experiment, we found that AG and PDTC inhibited the apoptosis of M phi induced by IFN(100 U.ml-1) + LPS (10 micrograms.ml-1) by using DNA gel electrophoresis analysis. These evidences support that NO and active oxygen species may be involved in the apoptosis process of peritoneal M phi induced by LPS in mice.

[p53 gene expression of human hepatoma cell lines and their sensitivities to parvovirus H-1]

DNA structure and expression of p53 gene in human hepatoma cell lines SMMC-7721, YY-8103 and a spontaneously transformed liver cell line L-02 were analysed using the following method: analysis of allelic losses on chromosome 17p, PCR/SSCP, Northern blot and immunoprecipitation. There was no point mutation found in the exons 4-9 of the p53 gene, and a low level of expression of p53 gene was detected in the three cell lines. These observations were in agreement to the reported results of the relevant experiment using the human hepatoma cell line QGY-7703. Sensitivities of these cell lines and other eight human hepatoma cell lines (QGY-7703, PLC/PRF/5, Tong/HCC, Huh-7, FOCUS, Hep3B, SK-Hep-1, HepG2) with known p53 backgrounds to parvovirus H-1 was assayed using MTT method. Abnormality in the structure and/or function was observed in all of the cell lines examined except HepG2. The cell line HepG2 with normal structure and function of the p53 gene was found to be the least sensitive to H-1 in comparison to all the cell lines which have defeated structure and/or function of the p53 gene. The present study serves as a preliminary evidence that enhancement of the sensitivity of human hepatoma cell lines to H-1 is correlated to the abnormality of the structure and/or function of the p53 gene.

[Inhibition of parvovirus H-1 on transplantable human hepatoma and its histological and histobiochemical studies]

A transplantable human hepatoma model, the QGY-9204, was used in this study. The growth kinetics of hepatoma in nude mice were compared after injection of parvovirus H-1 into the tumor growth. Significant difference in growth curves were seen between injected groups with H-1 dosages of 5 x 10(7) PFU and 5 x 10(8) PFU and that of control. It indicated that parvovirus H-1 was capable of suppressing the growth of human hepatoma. Previous studies showed H-1 is oncotropic, oncosuppressive and oncolytic. For histological, ultrastructural and histochemical examinations, transplantable hepatomas were taken at different time interval post H-1 (1 x 10(8) PFU per tumor growth) injection. For H-1 DNA amplification and H-1 nonstructural protein expression, PCR and ABC approach in hepatoma paraffin sections were used. The H-1 treated groups exhibited obvious signs of necrosis. It started on 3rd day post infection (3 d.p.i.) and the area of necrosis enlarged consecutively on 7 d.p.i., 10 d.p.i. and 14 d.p.i., but none was seen in saline-injected group even on 14 d.p.i. H-1 virions were also detected in the damaged tumor cells with numerous vacuoles in cytoplasm. Specific band (908 bp) of H-1 DNA and ABC immunostaining indicated H-1 DNA replication and NS-1 expression in tumors of treated groups, their time course was well in accordance with that process of necrosis. These results suggest that parvovirus H-1 promotes tumor necrosis by its DNA replication and cytotoxic NS-1 protein expression, and thus, it inhibits hepatoma growth and induces oncosuppression and oncolysis.

[Studies on the iridoid glucosides of the root of Lamiophlomis rotata (benth.) kudo, a medicinal plant in Xi zang (Tibet)]

Lamiophlomis rotata (Labiatae) is a Chinese folk medicinal plant in Xi-zang (Tibet), which has effects of promoting blood circulation to remove blood stasis, subduing swelling and alleviating pain. Four iridoid glucosides were isolated from the root of the species. On the basis of IR, UV, NMR, MS spectral data and chemical methods, their structures were identified as: 8-O-acetylshanzhiside methyl ester(I), 6-O-acetylshanzhiside methyl ester(II), penstemoside(III) and 7, 8-dehydropenstemoside(IV). The last one is a new compound.

Heat shock pretreatment prevents hydrogen peroxide injury of pulmonary endothelial cells and macrophages in culture

The purpose of the present study was to determine whether heat shock pretreatment would protect pulmonary endothelial cells and alveolar macrophages against hydrogen peroxide (H2O2)-induced injury. The bovine pulmonary artery endothelial cells (BPAECs) heat-shocked (42 degrees C for 2 h) prior to exposure to H2O2 (1 mmol/L for 45 min) showed significant decrease in H2O2-mediated increment of release of lactate dehydrogenase and production of thiobarbituric acid-reactive substances, and obvious alleviation in H2O2-induced decrease in activities of catalase and superoxide dismutase. Heat-shocked (42 degrees C for 2 h) rat pulmonary alveolar macrophages (PAMs) also obtained acquired resistance to injury by subsequent exposure of 1, 2, or 3 mmol/L H2O2 for 45 min. Simultaneously with this acquired oxidative resistance, Northern blot analysis showed that heat-shocked BPAECs and PAMs, contained an increased level of mRNA coding for the inducible form of heat shock protein 70 (HSP70), and Western blot analysis indicated that there were increased expression of HSP70. Inhibition of protein synthesis by cycloheximide (25 micrograms/mL) and inhibition of RNA synthesis by actinomycin D (5 micrograms/mL) prevented the cytoprotection against H2O2. These results are consistent with the hypothesis that heat shock pretreatment would protect pulmonary endothelial cells and alveolar macrophages against H2O2-induced injury, and possibly that HSPs play a role in this cytoprotection.

Protective effect of anisodamine on cultured bovine pulmonary endothelial cell injury induced by oxygen-free radicals

Anisodamine, a Chinese traditional medicine herb, has been used for treatment of adult respiratory distress syndrome effectively, but little is known about its mechanism. We attempted to investigate if anisodamine could protect bovine pulmonary endothelial cell injury induced by exogenous oxygen-free radicals that were generated by xanthine/xanthine oxidase or opsonized zymosan-stimulated polymorphonuclear leukocytes. Results showed that with the addition of xanthine/xanthine oxidase into cultured bovine pulmonary endothelial cells, production of malondialdehyde and release of lactate dehydrogenase in supernatant increased, and synthesis of prostacyclin decreased. Damaged cellular membranes were revealed by scanning electron microscopy. The same was true for the addition of opsonized zymosan-stimulated polymorphonuclear leukocytes. While treatment with anisodamine greatly attenuated all of the above-mentioned parameters, results showed that (1) cultured bovine pulmonary endothelial cells could be damaged by oxygen-free radicals, (2) anisodamine had a protective effect on this injury as effective as that of superoxide dismutase and catalase, and (3) the membrane-stable action might contribute to the mechanism of protective effect against this injury.

[Sulfur dioxide-induced bronchial constriction in asthmatics and its prophylaxis by salbutamol]

Patients with bronchial asthma often develop acute attack in kitchen while burning honeycomb briquet which is widely used for cooking in southern China. Burning of a honeycomb briquet produces 0.6-4.3 ppm sulphur dioxide (SO2) in the kitchen air. To assess whether the above concentration of SO2 can induce bronchial constriction, we performed SO2 bronchial provocation test on 21 asthmatics (male 11, female 10, average age 28.8 +/- 2.0 years), 10 patients with allergic rhinitis (male 3, female 7.28 +/- 1.6 years) and 20 healthy non-smokers (male 13, female 7, 28.1 +/- 1.5 years). FEV1 showed no significant change in both healthy and rhinitis group even a maximal amount of SO2 (10 ppm) was given. The calculated PC20 FEV1 and PC35 SGaW in asthmatics were 3.7 +/- 0.22 ppm and 2.5 +/- 0.18 ppm respectively, which fell into the SO2 range yielded by a burning honeycomb briquet. Orally administered slow release salbutamol created protective effect in 5 out of 8 patients. Salbutamol inhalation, however, completely blocked SO2 induced bronchial constriction. We suggest that patient with bronchial asthma should receive salbutamol aerosol inhalation before cooking with burning honeycomb briquet.

Molecular electrostatic potential studies on some nitroimidazolyl and nitroheterocyclic compounds

The electronic wave functions of 11 nitroimidazolyl and nitroheterocyclic compounds were computed using the CNDO/2 quantum chemical method. The location of the greatest nucleophilic reactivity for each molecule was predicted to be mostly near or on the nitro group. As in our previous publication (Lin Liming et al. 1985) the maximum values of the superdelocalizability index for nucleophilic reactivity S(N)max and the sum of S(N)r for each of these compounds were discovered to be significantly correlated with the radiosensitivity as indicated by log(1/C1.6), where C1.6 is the concentration of the compound required to achieve an enhancement ratio of 1.6. The electrostatic potential distribution on a plane parallel to the plane of the imidazole or heterocyclic ring was computed for these compounds with the wave functions obtained from CNDO/2 calculations. In order to analyse the steric electrostatic potential maps, the overall electrostatic potential on an imaginary surface surrounding a molecule was calculated using the multicentre multipole expansion method. It was found that a wide and deep negative potential area exists in a compound which had significant radiosensitizing efficiency, while in metronidazole, which is not an efficient radiosensitizer, the corresponding area is narrow. This phenomenon may be related to the interaction between these compounds and certain biological macromolecules. These preliminary quantum chemical results support Adams' electron affinity theory, and might be helpful in searching for new radiosensitizers.

Positive selection of human cells lacking several transformation parameters from an SV40-transformed culture by means of parvovirus H-1

The simian virus 40 (SV40)-transformed, newborn human kidney cell line NB-F was found to be heterogeneous with respect to its sensitivity to parvovirus H-1. The majority of the cells sustain a productive H-1 infection which eventually causes their lysis. Yet, a small fraction of the cells appears to be much less susceptible to H-1. Such a resistance to H-1 infection is a stable, transmissible property of this subpopulation of cells which was denoted NB-FR. The heterogeneity of NB-F cells is also apparent from the distribution of their karyotypes, which is bimodal and peaks at 114 and 46 chromosomes/cell. In contrast, the great majority of NB-FR cells contain 41-50 chromosomes. H-1-resistant and -sensitive cells appear to be related in several respects: they both contain morphologically human chromosomes as well as multiple SV40 DNA inserts, and could not be distinguished by isoenzyme typing. It was investigated whether the degree of sensitivity to H-1 infection correlated with other phenotypic properties of the human cell derivatives. NB-F cultures exhibit a series of transformation parameters, such as SV40 T-antigen expression, poor contact inhibition, clonogenicity in semi-solid medium and high lectin agglutinability, which are all much reduced or even undetectable in NB-FR cells. These observations suggest that cell susceptibility to H-1 segregates with marker(s) of in vitro malignant transformation. Moreover, the data indicate that parvoviruses can be used to preferentially remove transformants from a mixed culture of normal and transformed cells.

Inhibitory effect of parvovirus H-1 on cultured human tumour cells or transformed cells

The present study establishes the in vitro system for studying the oncosuppression activity of parvovirus and discovers that parvovirus H-1 can be grown cytolytically in various human cancer cell lines, which include 4 hepatoma cell lines (QGY-7703, SMMC-7721, Bel-7402, PLC/PRF/5), 3 gastric cancer cell lines (SGC-7901, MGC-80-3, MKN-28) and 1 naspharynx cancer cell line (CNE). The growth of two primary gastric cancer cell cultures from surgical cancer tissue were also inhibited by the infection of H-1. The sensitivity of cancer cells to H-1 may relate to their differentiation states. On the contrary, H-1 can neither be grown cytolytically in normal liver or stomach cells, nor inhibit their growth. Transformation of human skin fibroblasts with Simian Virus 40 activated their sensitivity to H-1. Our results thus indicate that the antineoplastic activity of H-1 in vivo involves at least its direct inhibiting or killing malignant cells.