[Spatial autocorrelation and related factors of stroke mortality in Zhejiang Province based on spatial panel model in 2015-2020]

Objective: To explore the spatial autocorrelation and macro influencing factors of stroke mortality in Zhejiang Province in 2015-2020 and provide a scientific basis for stroke prevention and control strategy. Methods: The data on stroke death were obtained from Zhejiang Chronic Disease Surveillance System. The spatial distribution of stroke mortality was explored by mapping and spatial autocorrelation analysis. The spatial panel model analyzed the correlation between stroke mortality and socioeconomic and healthcare factors. Results: From 2015 to 2020, the average stroke mortality was 68.38/100 thousand. The standard mortality of stroke was high in the areas of east and low in the west, high in the south and low in the north. Moreover, positive spatial autocorrelation was observed (Moran's I=0.274-0.390, P<0.001). Standard mortality of stroke was negatively associated with per capita gross domestic product (GDP) (β=-0.370, P<0.001), per capita health expenditure (β=-0.116, P=0.021), number of beds per thousand population (β=-0.161, P=0.030). Standard mortality of ischemic stroke was negatively associated with per capita GDP (β=-0.310, P=0.002) and standard management rate of hypertension (β=-0.462, P=0.011). Standard mortality of hemorrhagic stroke was negatively associated with per capita GDP (β=-0.481, P<0.001), per capita health expenditure (β=-0.184, P=0.001), number of beds per thousand population (β=-0.288, P=0.001) and standard management rate of hypertension (β=-0.336, P=0.029). Conclusions: A positive spatial correlation existed between stroke mortality in Zhejiang Province in 2015-2020. We must focus more on preventing and controlling strokes in relatively backward economic areas. Moreover, to reduce the mortality of stroke, increasing the investment of government medical and health funds, optimizing the allocation of medical resources, and improving the standard management rate of hypertension are important measures.

[Management of Fournier gangrene in perineal region by negative-pressure wound therapy combined with delayed repair]

Objective: To explore the effects of negative pressure wound therapy (NPWT) combined with delayed repair on Fournier gangrene in perineal region. Methods: During July 2010 to September 2018, 16 patients with Fournier gangrene in perineal region were admitted to our center, with 13 males and 3 females, aged 30 to 76 years. In the first stage, the necrotic tissue of the wound was completely removed according to the scope of the lesion, and NPWT was applied. After the operation, general anti-infection and nutritional support were performed. In the second stage, the local flaps, free flaps, or skin grafts were chosen to repair the wounds according to the specific condition of wounds. The average length of stay and pathological diagnosis were recorded, and the survival and follow-up of skin grafts and flaps were recorded. Results: All the 16 patients were cured and discharged, with an average of 29.6 days in hospital. The pathological diagnosis of biopsies were necrotizing inflammation. The wound of 1 patient was healed directly after only NPWT, the skin grafts of 5 patients, local flaps of 9 patients, and anterolateral thigh island flap of 1 patient who had NPWT combined with delayed repair survived well. Sixteen patients were followed up for 1 to 2 years after discharge, and no recurrence of Fournier gangrene was found. Among them, 5 patients with wounds involved perineum and scrotum had good appearance and function of scrotum and mons pubis. Conclusions: NPWT combined with delayed plastic repair have great effects on Fournier gangrene.

[Investigation of epidemic status of clonorchiasis sinensis in western regions of Jilin Province]

OBJECTIVE

To understand the epidemic status of clonorchiasis sinensis in western region of Jilin Province, so as to provide the evidence for formulating the planning and strategy of prevention and control of the disease.

METHODS

In 2017, the areas where the residents had the customs of eating Sashimi were selected as the research areas in the western region of Jilin Province, and according to the cluster sampling, 25 villages in 25 towns (each village per town) of 5 counties in the region were selected as the investigation points. The basic information of crowd was collected by a questionnaire investigation. The Kato-Katz method was used for etiological examinations. The results were analyzed statistically.

RESULTS

A total of 4 980 people in the 25 villages were investigated, and 1 220 people were infected with Clonorchis sinensis. The average infection rate was 24.50%. There was a significant difference among different counties (cities, districts) in the infection rate of C. sinensis (P < 0.01), and the infection rate in Daan City was the highest (53.82%). In addition, there were significant differences between/among the gender, nation, age, educational level, and occupation in the infection rate (all P values < 0.01). The infection rate of the male was higher than that of the female, the rate of Han was higher than that of other ethnic groups, the rate of the high age group was higher than that of the low age group, the rate of the college degree group was higher than that of the other educational level groups, the rate of the cadre was higher than that of the other occupation groups, and the rate of the group who had vermifuge before the investigation was lower than that of the group who did not have vermifuge.

CONCLUSIONS

The western region of Jilin Province is still the highincidence area of clonorchiasis sinensis. Therefore, the comprehensive control and prevention measures, such as giving vermifuge and health education, should be strengthened in key population and areas in the future.

[Evaluation on the effect of salt reduction intervention among fourth-grade primary school students and their parents in Shandong Province]

In order to evaluate the intervention effect of the school-based salt reduction model, 28 primary schools were selected in Shandong Province in September 2014 and randomly divided into intervention group (1 361 students, 1 306 parents) and control group (1 364 students,1 340 parents). A series of "small hands and big hands" salt reduction intervention activities were conducted in intervention group for 8 months. After the intervention, the total awareness rate of salt reduction knowledge, the total holding rate of related beliefs and the total reporting rate of related behaviors were 70.65%, 80.30% and 67.03% among students, and 85.66%, 93.77% and 87.93% among parents, in the intervention group, which were higher than those in the control group (37.12%, 66.52% and 50.07% among students; 55.11%, 87.52% and 57.96% among parents) (all P values <0.05). The school-based salt reduction model is effective and feasible.

The stability of Cu clusters and their adsorption for CH4 and CH3 by first principle calculations

Two-dimensional (2D) and three-dimensional (3D) Cu _n clusters (n indicates the atom number) and their adsorption behaviors for both methane (CH₄) and methyl (CH₃) are studied in this work using the density functional theory method, where n ranges from 6 to 20. In these small clusters, it is found that the CH₄ molecule is always adsorbed on the top site with the adsorption energy between -0.05 eV and -0.21 eV. Considering methane dehydrogenation, stronger adsorption for CH₄ is required, so 2D clusters with n = 7, 14, 15, and 16 and 3D clusters with n = 6, 10, 12, and 17 are found to have relatively stronger adsorption. However, for the adsorption of CH₃, there is an obvious even-odd oscillation change in the size of 3D clusters, while it is not clear in 2D clusters since one cannot find an even-odd change as n > 14. The weaker adsorption for CH₃ occurs on 3D clusters when n is even except 6 and also on 2D clusters when n = 6, 7, 10, and 12 with higher carbon poisoning resistance. Based on these calculated results, some Cu clusters which show good potential ability for methane dehydrogenation are provided, especially when n = 10 and 12 for 3D structures, and n = 7 for the 2D ones.

Ultraviolet lasing in Zn-rich ZnO microspheres fabricated by laser ablation

Zinc (Zn) surface plasmons (SPs) have been widely reported for their impressive performance in improving the optical properties of semiconductors. Zn is an effective metal with SPs response in the ultraviolet region, but the disadvantage of strong metal activity limits the application mentioned above. Here, in order to ensure the stability of metal Zn, ZnO/Zn microspheres were synthesized by an one-step laser ablation method to distribute Zn nanoparticles simultaneously on both inner and outer surfaces of ZnO microspheres. Lasing performance enhancement and a lower threshold were obtained in the composite which originates from the coupling between Zn SPs and the excitation light source. Accompanied by the lasing emission measurements, the coupling mechanism was explained through time-resolved photoluminescence spectroscopy (TRPL) for the samples by rapid annealing in situ. This work displays the results of lasing enhancement and the physical process of Zn SPs resonance in the ZnO/Zn microsphere.

[The effects of levosimendan on the cardiac function and prognosis in elderly patients with septic shock and myocardial contractility impairment]

Objective: To investigate the effect of levosimendan on cardiac function and prognosis in elderly patients with septic myocardial contractility impairment. Methods: A prospective, randomized, controlled study was conducted. The elderly patients with septic myocardial contractility impairment who were admitted to Intensive Care Unit in Zhejiang Hospital were consecutively enrolled from January 2017 to September 2017. The key inclusive criterion was left ventricular ejection fraction (LVEF) ≤50% after fluid resuscitation. A total of 30 patients were randomly assigned to levosimendan group (n=15) and dobutamine group (n=15). Based onconventional treatment, intravenous dobutamine (5 μg per kilogram of body weight per minute) or levosimendan (0.2 μg per kilogram of body weight per minute)were continuously administrated for 24 hours in two groups. At 0 h,24 h,48 h, 72 h after injection, the following parameters or values were recorded including serum lactic acid (Lac), and echocardiographic parameters such as LVEF, stroke volume (SV). The time of mechanical ventilation, length of stay in ICU and 28-day mortality were compared in two groups. Results: Compared with dobutamine group, blood Lac at 24 h [(1.97±1.10)mmol/L vs. (2.73±2.06) mmol/L, P=0.002] decreased significantlyin levosimendan group. LVEF and SV were significantly higher in levosimendan group at 24 h [LVEF:(47.93±5.01)% vs.(45.60±5.47)%, P=0.004;SV:(47.73±14.01) ml vs. (44.80±16.89) ml, P=0.035;respectively], 48 h [LVEF:(51.07±5.05)% vs.(46.73±6.34)%, P=0.004;SV: (49.87±14.15) ml vs. (45.07±16.94) ml, P=0.005;respectively] and 72 h [LVEF:(53.20±5.92)% vs. (47.70±6.71)%, P=0.002;SV:(51.27±14.98) ml vs. (45.73±17.34) ml, P=0.010]. The time of mechanical ventilation, length of stay in ICU and 28-day mortality were comparable between two groups (P>0.05). Conclusions: Levosimendan improves cardiac systolic function and tissue perfusion in elderly patients with septic myocardial contractility impairment. However, cardiac diastolic function, liver and kidney function are not further improved by levosimendan compare with dubutamine. Time of mechanical ventilation, length of stay in ICU and 28-day mortality in two groups are similar.

Extra green light induced ZnO ultraviolet lasing enhancement assisted by Au surface plasmons

We observed the dramatic enhancement of the intrinsic spontaneous and stimulated emission as well as the ensuing suppression of defect-related green emission in Au-decorated ZnO microrods. A series of spectral experiments and theoretical analysis demonstrated an electron transfer assisted process by surface plasmon (SP) resonant coupling between the Au nanoparticles and ZnO. The mechanism indicates an approach to enhance the UV emission of ZnO through an extra excitation of visible light similar to that for the defect emission of ZnO. Based on the coupling mechanism, the externally enhanced ultraviolet lasing was further improved from 1.5 to 2.8-fold by adjusting the pumping power of the green light intensity in the Au/ZnO hybrid cavity. This research not only further confirms the SPR-assisted electron transfer process but also offers an approach to improve the intrinsic UV emission even for heavily-defected ZnO through visible light excitation via a nonlinear process.

[Prevalence, awareness, treatment and control of hypertension in adults in Shandong province, 2013]

Objective: To understand the prevalence, awareness, treatment and control of hypertension in adults in Shandong province in 2013. Methods: Adults aged ≥18 were selected through multistage clustering sampling in 19 counties and districts in Shandong province. Design-based methods were adopted to analyze the prevalence, awareness, treatment and control of hypertension among local residents. Results: A total of 11 270 adults aged 18-69 years were surveyed, the prevalence of hypertension was 27.9% (31.4% in males, 24.3% in females) in Shandong province. The awareness rate of hypertension was 37.4% (34.7% in males, 41.0% in females), and the treatment rate of hypertension was 26.6% (23.4% in males, 30.7% in females). The treatment control rate of hypertension was 26.7% (28.3% in males, 25.1% in females) and the control rate of hypertension was 7.1% (6.6% in males, 7.7% in females). Conclusions: The prevalence of hypertension was high, but the awareness rate of hypertension, the treatment rate and the control rate of hypertension were low in adults in Shandong province. It is necessary to strengthen the health education about hypertension in young population, the prevention and control of hypertension in old population and those with low education level, the standardized management of hypertension cases and the reduction of risk factors for hypertension.

Lasing mode regulation and single-mode realization in ZnO whispering gallery microcavities by the Vernier effect

The wide direct bandgap and strong exciton binding energy of ZnO have inspired examinations of ultraviolet lasing over the previous decades. However, regulation of the lasing mode, especially the realization of single mode lasing, is still a challenge. In this study, a ZnO comb-like structure with an array of microrods was selected to design coupled whispering-gallery-mode cavities, wherein the naturally varied air-gap between the adjacent microrods created a flexible condition for optical field coupling without any complicated micromanipulation. Spectral behaviour of lasing and coupling interaction between coupled ZnO microrods were systematically investigated. By regulating the nano-scale inter-space of dual coupled microrods, stable single-mode lasing with a higher Q factor and lower threshold was obtained successfully based on the Vernier effect. The formation conditions and the mechanism of single-mode lasing derived from the coupled ZnO microrods were discussed in detail. It also demonstrated an approach to construct high quality single-mode lasing by tuning the diameters of the coupled ZnO microrods.

Eutectic condensation and nucleation in vapor-liquid-solid grown ZnO nanorod arrays on Si substrate

It is very important to understand the growth mechanism of ZnO nanostructures for control of the morphologies and further design of optoelectronic devices. In this paper, the eutectic condensation of Zn vapor and catalyst Au, nucleation and epitaxy of ZnO nanorods were intuitionally observed in chemical vapor deposition process by controlling the temperature and atmosphere. The vertically aligned ZnO nanorod arrays were fabricated on Au-coated Si substrate. A Zn-riched buffer layer was found on Si substrate. Under the atmosphere nearly without O2, it was clearly observed that the nano-sized sprouts appeared on the buffer layer and Au-Zn condensed bigger and bigger with increase of temperature. When the O2 was introduced, the as-grown nanorods almost kept the same size and density with those sprouts grown at the same temperature without O2. The morphologies and composition analysis provided direct evidence for a bottom-catalyzed vapor-liquid-solid mechanism of ZnO nanorod arrays on the lattice-mismatched substrate.

Conjugated linoleic acid synthesis-related protein proteasome subunit α 5 (PSMA5) is increased by vaccenic acid treatment in goat mammary tissue

This study was conducted to identify proteins associated with the endogenous synthesis of conjugated linoleic acid (CLA) from trans-vaccenic acid (TVA; trans-11 C18:1, a precursor for CLA endogenous synthesis) in mammary tissues. Six lactating goats were divided into 2 groups. One group was given an intravenous bolus injection of TVA (150mg) twice daily over 4 d; the other group received saline injections. Treatment with TVA increased the concentration of cis-9,trans-11 CLA and TVA in goat milk. Additionally, TVA treatment increased the expression of stearoyl-CoA desaturase (SCD) in mammary tissue. Using 2-dimensional gel electrophoresis and electrospray ionization quadrupole time-of-flight mass spectrometry, 3 proteins affected by infusions of TVA were identified. Proteasome (prosome, macropain) subunit α type 5 (PSMA5) was upregulated, whereas peroxiredoxin-1 and translationally controlled tumor protein 1 were downregulated in TVA-treated animals compared with the vehicle-injected controls. Only the effect of TVA on PSMA5 could be confirmed by Western blot analysis. To further explore the regulation of PSMA5 in mammary epithelial cells when TVA is converted into CLA, we used a differentiated bovine mammary epithelial cell line treated with TVA for 6h. Changes in cis-9,trans-11 CLA concentrations and mRNA expression patterns of both SCD and PSMA5 were monitored. The concentration of cis-9,trans-11 CLA increased after TVA treatment. The mRNA expression level of PSMA5 was significantly elevated to 6h, but SCD mRNA expression only increased in 2h after TVA treatment. These results indicate that PSMA5 is highly expressed in goat mammary tissue and bovine mammary epithelial cells when TVA is converted into CLA. Our data suggest that PSMA5 protein is associated with CLA biosynthesis in mammary tissue.

Fabrication and characterization of n-ZnO nanonails array/p(+)-GaN heterojunction diode

A novel heterojunctional structure of n-ZnO nanonails array/p(+)-GaN light-emitting diode was fabricated by Chemical Vapor Deposition method. A broad electroluminescence spectrum shows two peaks centered at 435 nm and 478 nm at room temperature, respectively. By comparing the photoluminescence and electroluminescence spectra, together with analyzing the energy band structure of heterojunction light emitting diode, it suggested that the electroluminescence peak located at 435 nm originates from Mg acceptor level of p(+)-GaN layer, whereas the electroluminescence peak located at 478 nm originates from the defects of n-ZnO nanonails array.

Polybrominated diphenyl ethers in leaves and soil from typical electronic waste polluted area in South China

Polybrominated diphenyl ethers (PBDEs) in leaves and soil from typical e-waste polluted area in South China were investigated. The concentrations (ng/g dry weight) of PBDE congeners and summation operatorPBDE of five leaf samples were much lower than those in soil sample. The general patterns of summation di-BDEs to summation hepta-BDEs percentage distribution in leaf samples were similar to those of the soil sample, except the percentage of BDE209 which were lower than in soil. The percentages of summation di-BDEs to summation hepta-BDEs in soil were in the range of those in leaf samples. The results showed that the contamination of PBDEs in the leaf samples had good correlation with the soil around them.

Nestin expression in different tumours and its relevance to malignant grade

BACKGROUND

Nestin, an intermediate filament (IF) protein, is expressed in proliferating progenitor cells of developmental and regenerating tissues, and is identified as a neuroepithelial precursor cell marker. Recently, nestin was detected in some neoplasms such as glioma, ependymoma, melanoma, rhabdomyosarcoma, gastrointestinal stromal tumour (GIST), and testicular stromal tumour. Moreover, the expression intensity of nestin exhibited significant correlation with the malignant grade of glioma.

AIMS

To detect the expression of nestin in different tumours and to analyse the relationship between the expression of nestin and the malignant grade of the tumours.

METHODS

Formalin-fixed and paraffin-embedded surgical samples of neoplastic tissues were obtained from the Department of Pathology of Sun Yat-sen University. Histological analysis and immunohistochemical staining for nestin were performed. Histoscores were analysed by semi-quantitative evaluation.

RESULTS

Nestin was expressed predominantly in the cytoplasm of angiosarcoma, pancreatic adenocarcinoma and GIST samples, and some tumour cells expressed in the nucleus. There was a statistically significant difference between the histoscore of nestin in high malignant GIST (2.2366 (0.6920)) and that in low malignant GIST (1.3783 (0.4268)) (p = 0.003); and also between that in high malignant angiosarcoma (1.9188 (0.2069)) and that in low malignant angiosarcoma (0.6474 (0.3273)) (p = 0.000). Cavernous angioma did not express nestin. The histoscore of nestin in high malignant pancreatic adenocarcinoma (7/14) was 1.1767 (0.4676), and that in low malignant pancreatic adenocarcinoma (3/8) was 0.6577 (0.0056) (no significant difference, p = 0.112).

CONCLUSIONS

Results suggest that the expression of nestin may play an important role in the development of some neoplasms such as GIST and angiosarcoma.

The responseof plasma leptin and feed intake to growth hormone administration in Holstein calves with different planes of nutrition

This study was conducted to observe the effect of the growth hormone (GH)/insulin-like growth factor-1(/IGF-1) axis on leptin and feed intake of 15 Holstein calves in three groups. One group was fed a normal diet (control); the second group, with high nutrition after low feeding with bovine growth hormone (bGH), and a third group, without high nutrition (saline) after low feeding. Each group was intramuscularly (i.m.) injected daily with bovine GH (200 µg kg-1 d-1) or saline solution for 10 d. No significant differences were found in the concentrations of plasma leptin over time for a 24-h period. Plasma leptin was decreased in both saline and GH groups during low and high nutrition regimes, respectively, while IGF-1 levels increased for both nutrition regimes (P < 0.05). With GH treatment during refeeding periods (P < 0.05), leptin levels increased and feed intake decreased; however, the plasma leptin levels slightly decreased with GH treatment during low feeding periods. The plasma IGF-1 concentration increased with GH administration during normal and refeeding periods (P < 0.05). These results indicate that the response of plasma leptin levels to GH varied according to the nutritional condition. In addition, the GH/IGF-1-induced increase in leptin production during the refeeding period may serve as a signal to reduce the feed intake or to increase dramatically after feed restriction in cattle. Key words: Feed intake, growth hormone, leptin, insulin-like growth factor-1, Holstein calves

Growth mechanism of tubular ZnO formed in aqueous solution

Tubular ZnO microstructural arrays were fabricated by a hydrothermal decomposition method. The dependence of the morphologies on the growth time and temperature was investigated in detail. An experiment was carried out to determine the mechanism of tubular ZnO formation. Our results showed that ZnO microtubes originated from an ageing process from ZnO microrods at a lower temperature (compared to the temperature when hydrothermal deposition of ZnO microrods was dominant) due to the preferential chemical dissolution of the metastable Zn-rich (0001) polar surfaces. A growth model was proposed based on the coexistence of hydrothermal deposition and dissolution of ZnO in the fabrication process.

Apoptosis and hormonal milieu in ductal system of normal prostate and benign prostatic hyperplasia

AIM

To study the apoptotic rate (AR) and the androgen and estrogen milieu in the proximal and distal ductal systems of prostate, in order to help exploring the effects of these factors on prostatic growth and the pathogenesis of benign prostatic hypertrophy (BPH).

METHODS

The proximal and distal ends of the ductal system were incised from 20 normal prostate as well as the hypertrophic prostate tissue from 20 patients with BPH. The AR was determined by the DNA end-labeling method and dihydrotestosterone (DHT) and estrodiol (E2), by radioimmunoassay.

RESULTS

There was no significant difference in DHT and E2 density between the proximal and distal ends of the ductal systems in normal prostate. E2 appeared to be higher in BPH than in normal prostatic tissues, but the difference was statistically insignificant. In normal prostatic tissue, the AR was significantly higher in the distal than in the proximal ends of the ductal system (P < 0.05), while the AR of the proximal ends was significantly higher (P < 0.01) than that in the BPH tissue. No significant correlation was noted between the DHT and E2 density and the AR both in the normal prostate and BPH tissues.

CONCLUSION

The paper is the first time describing a difference in AR in different regions of the ductal system of normal prostate, while the hormonal milieu is similar, indicating a functional inhomogeneity of these regions. A low AR in the proximal duct, where BPH originates, and an even lower AR in the BPH tissue, suggesting the participation of apoptosis in the BPH pathogenesis.

[Analyse of the site of lesion in auditory neuropathy]

OBJECTIVE

To analyze the clinic signs, the site of lesion and terminology of a kind of hearing loss which is characterized by speech hearing loss.

METHOD

The data of 11 patients were collected and analyzed including the clinic symptoms, pure tone audiometry, acoustic impedance audiometry, auditory brainstem response (ABR), electrocochleogram(ECochG), distortion product otoacoustic emission (DPOAE), CT/MRI.

RESULT

All these cases had following contradictory phenomena: Pure tone audiograms were low-frequency hearing loss; ABRs were absent or seriously abnormal, and ABR response threshold was worse than pure tone threshold and click subjective threshold; ECochG could be recorded in some patients; The stapes muscle reflex was absent; DPOAEs were normal or near normal, the average amplitude of low-frequency was higher than normal hearing group, but the average amplitude of high frequency was lower than normal hearing group; The imaging examination did not show any abnormality.

CONCLUSION

All data of this group show that the sites of lesion in most patients may be in lower brainstem, but the sites of lesion in some patients may be in the spiral ganglion of cochlea. The research of this disease should be continued.

Anticancer effect of Howiinol A and its mechanism of action

Howiinol A (GHM-10) is a kind of phenylethylene pyrone compounds isolated from Goniothalamus howii. By using the techniques of cell growth curve determination, MTT test, soft agar colony assay and experimental therapy of transplantable tumors in mice, it is found that GHM-10 exerts potent inhibitory effect on cancer cells but its influence on normal cells is relatively slight; the sensitivity of a drug-resistant cell line, KB/VCR 2000, to GHM-10 is similar to its parent cell line KB. Remarkable therapeutic effect can be seen in mice bearing H22 hepatoma and Lewis lung cancer and in mice with ascetic sarcoma 180 when GHM-10 is orally or intraperitoneally administered. The IC50s of L1210 cells treated with GHM-10 for 1 and 24 h are 6.85 and 3.32 micrograms.ml-1 respectively. The ratio of IC50 1 h and IC50 24 h is only 2.06, indicating that the action of GHM-10 is conformed to a cell cycle non-specific cytotoxic agent. By using trypan blue exclusive test and morphological examination, it is demonstrated that the main effect of GHM-10 is to inhibit the cell proliferation. Flow cytometery technique is used to analyze the cell cycle of L1210 cells. The results show that to some extent, GHM-10 blocks the cell cycle transition from G1 phase to S phase. By using [3H] labeled precursor incorporation technique, it is shown that GHM-10 significantly suppresses the biosynthesis of DNA, RNA and protein in L1210 cells, and the DNA synthesis is mostly affected. At 1 h after the cells were treated with GHM-10, these inhibitory effects have already been irreversible, suggesting that GHM-10 may cause structural damage on DNA molecules. However, GHM-10 is unable to intercalate into DNA molecules or to destroy its structure directly. By using single cell gel electrophoresis and alkaline elution technology, it is confirmed that GHM-10 causes DNA molecule damage and single strand breakage in L1210 cells. Further studies show that GHM-10 markedly inhibits DNA dehelix induced by DNA topoisomerase II both inside and outside the cells, indicating that GHM-10 is acting as an inhibitor of DNA topoisomerase II.

[Effect of HH07A, A derivative of hainanensine, on DNA polymerase I]

The effect of HH07A on DNA polymerase I in a cell free system was studied. The results showed that HH07A strongly inhibited the DNA synthesis catalyzed by DNA polymerase I in a dose dependent manner. Further results indicated that the DNA synthesis decreased significantly after DNA polymerase I was preincubated with HH07A. However, no change was found when DNA template was preincubated with HH07A. These results suggest that the inhibitory action of HH07A appeared to be on the enzyme molecules rather than on the DNA template.

[Studies on the anticancer effect of HH07A, a derivative of hainanensine]

The effect of HH07A on the growth of tumor cells in vitro was investigated using the techniques of cell growth curve determination and soft-agar colony-forming assay. The result showed that HH07A inhibited the growth of L1210 cells and HL-60 cells at a concentration of 1.5 micrograms.ml-1 and 4.0 micrograms.ml-1, respectively. Among the cells tested, L1210 cells were shown to be the most sensitive, followed by KB cells and HL-60 cells (with IC50 of 2.29, 4.13 and 4.36 micrograms.ml-1, respectively). Normal mouse granulocyte-macrophage progenitor cells (GM-CFC) were less sensitive to the drug (with IC50 of 11.15 micrograms.ml-1) as compared with the tumor cells. As they were exposed to HH07A 3.5 micrograms.ml-1 for 5 days, HL-60 cells did not show NBT reductive ability. Intraperitoneal injection of HH07A exerted inhibitory effect on the ascitic tumors of L1210 and S180 in mice. Oral or ip administration of HH07A also showed some effect on S180 solid tumors in mice.

Preparation and performance of cross-linked agar encapsulated activated charcoal (CAAC-III)

A technique is described to encapsulate activated charcoal for hemoperfusion to be used in an artificial liver support. Spherical activated charcoal was coated with agar and shaped in organic solvent, as well as cross-linked by epichlorohydrin (40-50 degrees C). The product withstood autoclaving at 121 degrees C for 0.5 hours, and had a good adsorption ability for compounds with molecular weight ranging from 113-5200. The adsorption kinetic showed pore diffusion limitation to compounds of small molecular weight, and film diffusion limitation to compounds of large molecular weight. Microparticles of charcoal release were greatly reduced, and within the permissible range according to the requirements in the U.S. Pharmacopeia (1985).

[Influence of radix Astragali on noise-caused changes in hepatic glycogen content in the rat]

It has been found that in rats exposed to a noise of 2kHz (mai frequency) and 103 dB(A) (potency) for 60 minutes, the hepatic glycogen content (HGC) is significantly higher than that of the control group unexposed to the noise (P less than 0.05), whereas in those treated with a prior ip Radix Astragali plus noise the HGC appears apparently lower than that of the noise group (P less than 0.05), very close to the control group (P greater than 0.2). This indicates that Radix Astragali might have some antinoise effect.

[Cytocidal action of homoharringtonine on L1210 cells in vitro]

The proliferation of L 1210 cells ceased rapidly after they were exposed to homoharringtonine (HH) 1 microgram/ml during exponential growth phase. However, 25.3% of the cells were still able to form colonies in soft agar if HH was removed after 24 h of incubation (the colony-forming efficiency for control cells was 62.5%). The clonogenic cells survived from the treatment were still sensitive to HH-continuous exposure. The IC50 of the treated and control cells were 15 and 20 ng/ml, respectively. Yet, the sensitivity of the treated cells to cytarabine decreased enormously. For instance, the survival rate of HH-treated cells remained at 100% level after they were exposed to cytarabine 4-8 micrograms/ml for 1 h, but only 40% control cells survived from the same treatment. When cells were continuously exposed to HH 0.4 micrograms/ml, the colony-forming efficiency decreased exponentially as a function of exposure time. The T1/2 of the clonogenic cells was about 18 h. The DNA contents in L 1210 cells was measured with a flow-cytometer. The results showed that the cell-cycle progress in all cells was interrupted by HH, regardless which phase they belonged to. So the cells seemed to be in a "frozen" state and the histogram unchanged.

Residual deficiencies in hemopoietic precursor cell populations after repeated irradiation of mice with x-rays or neutrons: dose-response relationships

Persistent reductions in the femoral content of hemopoietic colony-forming cells (CFU-S and GM-CFC) were observed after four doses of irradiation, delivered with three weeks between doses. In general, the reductions were dose dependent, and similar reductions were produced by single doses and repeated doses using the same total dose. After the lowest doses investigated, 4 X 0.75 Gy 300-kVp x-rays or 4 X 0.38 Gy 14.7-MeV neutrons, the recovered levels remained at 60%-80% of control for at least one year after irradiation. The relative biological effectiveness (RBE) of neutrons is about 2 for these long-term hemopoietic deficiencies.

A comparison of low and high dose-rate radiation for recipient mice in spleen-colony studies

Over the last 15 years, endogenous spleen-colony formation in our mice, following lethal irradiation, has increased to an unacceptable level. It has been found necessary, therefore, to introduce a new method of preparing recipient mice for spleen-colony studies. Irradiation with low dose-rate 60Cobalt gamma rays has been compared with high dose-rate linear accelerator electrons, and their effects on endogenous spleen colony formation compared with earlier X and gamma ray dose-response data. It was found that a large dose (13.5 Gy) of gamma rays results in fewer endogenous colonies than 8.5 Gy of electrons, yet because of its low dose rate (14.1 X 10(-3) Gy/min) it has a marked sparing of the intestinal tissue as measured by the intestinal microcolony technique. This in turn permits better survival and, therefore, a 'healthier' animal for spleen-colony work. Exogenous colony formation is also lower in the low dose-rate, gamma-irradiated recipients and this is shown to be due to a reduced spleen-seeding efficiency. It is concluded that very low dose-rate radiation is preferable for haemopoietic ablation, that a mouse colony requires constant monitoring for changes of endogenous spleen-colony formation and that the spleen-seeding efficiency of CFU-s depends on the irradiation technique used--there is no absolute value for a given strain of mouse.

A cellular analysis of residual hemopoietic deficiencies in mice after 4 repeated doses of 4.5 Gray X rays

A sub-optimal plateau in numbers of femoral stem-cells (CFU-S) in mice after 4 doses of 4.5 Gray X rays (each separated by 21 days), was shown to persist at 20-30% of control up to 1 year after the last dose, when about 50% of the mice had survived. The concentration of white cells in the blood was maintained persistently at about 70% of control, whereas the concentration of red cells was normal up to 4 months and then it declined to about 75% of control at 10 months after irradiation. Concentrations of some committed progenitor cells in the marrow (GM-CFC and ERC), which are capable of amplification cell divisions, were intermediate between the concentrations of marrow stem cells and mature blood cells in both the granuloid and the erythroid cell lineages, respectively. Hence increased amplification was a mechanism operating for a prolonged period in the production of numbers of mature cells. The numbers were subnormal, however, and this corresponded to only 1 extra amplification division on average. There was a slow decline after 6 months in the numbers of CFU-S, BFU-E and GM-CFC, and in the hematocrit, with reference to age-matched controls. The decline was due partly to a prevention of the natural increase in cell numbers in the marrow with the age of the mice, which was also seen with the femoral content of a stromal progenitor cell (CFU-F). A defect in the repeatedly-irradiated CFU-S population was detected as a persistent inability to produce colonies containing the same number of daughter CFU-S as contained in colonies derived from unirradiated marrow and assayed at the same time.

The response of stromal progenitor cells in mouse marrow to graded repeated doses of X rays or neutrons

After four repeated doses of 1.5 Gy X rays to mice (3-week intervals), the number of colonies containing fibroblasts that could be grown in vitro from femoral marrow recovered to control numbers by 80 days. After four higher doses, recovery was incomplete, and after four doses of 4.5 Gy, the number was half of the control level up to 1 year after irradiation. After four doses of 14.7 MeV neutrons, no threshold was detected for this late effect, and the RBE was about 2 at 4.5 Gy X rays and about 6 at 1.5 Gy X rays. The RBE for the acute effect on the stromal progenitor cells was also about 2 at 4.5 Gy X rays. The stromal progenitor cells could not be spared relative to hemopoietic stem cells (CFU-S) after neutrons, in contrast to the sparing observed after low-dose fractions of X rays. Experiments with local X irradiations of the leg, and with subcutaneous transplants of femora, revealed no significant recovery of stromal progenitor cells due to migration. However, recovery in situ could be enhanced slightly by marrow grafts i.v.

Stromal colonies from mouse marrow: characterization of cell types, optimization of plating efficiency and its effect on radiosensitivity

Modifications to the colony assay in vitro for stromal progenitor cells in mouse femoral marrow have been studied so as to optimize the efficiency of colony formation (CFE). The highest reproducible concentration achieved was about 30 colonies (containing fibroblasts, macrophages and endothelioid cells) per 10(6) nucleated marrow cells (range 20–50) in mice 3–4 months old, and higher by 50% in mice 14–15 months old. Each of many slight technical modifications could reduce these values by more than 30%. The importance of optimization was demonstrated by a reduced radiosensitivity when the CFE was reduced by a factor of 3 using alpha-medium stored at 4 degrees C for 15 days. The D0 value was 3.9 +/− 0.8 Gy compared to 1.6 +/− 0.1 Gy using freshly prepared medium, and this could be due to the selection of a radioresistant subpopulation. The modifications studied may partly explain the marked variations in CFE and in radiosensitivity reported in the literature.