[Bronchoscopic manifestations and interventional treatment of pulmonary mucormycosis]

Objective: To analyze the bronchoscopic manifestations and interventional treatment of pulmonary mucormycosis. Methods: Clinical data of patients with pulmonary mucormycosis undergoing bronchoscopy and interventional therapy in 4 tertiary general hospitals in China from May 2006 to May 2022 were retrospectively analyzed and the literature on the subject were reviewed. Results: The data of 10 patients with pathologically diagnosed pulmonary mucormycosis undergoing bronchoscopy and interventional therapy were collected, including 8 males and 2 females. The patients' age ranged from 21 to 72 (44±15) years. The underlying diseases included 6 cases of diabetes ketoacidosis, 3 cases of leukemia, 1 case after operation of lung cancer. Bronchoscopy showed that white viscous necrotic matters grew along the airway and blocked the airway in 9 cases, accompanied by airway bleeding in 3 cases, bloody secretion blocked the airway in 1 case, and bronchopulmonary cavity fistula in 2 cases. The biopsy histopathology of white necrotic matters showed that many mucor filaments were tangled together which were named mucormycelium. Among the 10 patients, 9 were treated with systemic drugs, including intravenous application of amphotericin B deoxycholate in 5 cases, intravenous application of amphotericin B liposome in 4 cases, oral posaconazole in 6 cases and intravenous injection in 1 case. Local drug therapy included aerosol inhalation of amphotericin B deoxycholate in 8 cases and local perfusion under bronchoscope in 5 cases. Bronchoscopic interventional therapy was used to remove mucormycelium in the bronchus, including cryotherapy in 8 cases, biopsy forceps in 7 cases, snare treatment in 2 cases and foreign body forceps in 2 cases. All 10 patients were clinical cured and with no death. Conclusions: Pulmonary mucormycosis is more common in immunocompromised hosts. Bronchoscopy often showed mucormycelium blocking the airway. Systemic and local drug therapy combined with bronchoscopic interventional therapy can achieve good clinical efficacy.

Fate and removal of antimony in response to stringent control activities after a mine tailing spill

When tailing spill accidents occur, the risk of contamination by antimony (Sb) tailings into adjacent rivers, sediments, aquifers and soil environments is high. The Sb concentrations in water and sediment under different stringent control activities were investigated for 60 days in the Jialing River basin after a tailing spill accident. Both reservoir regulation and the construction of a temporary dam with coagulation dosing remarkably reduced the Sb levels in the river water. The increase in dissolved Sb caused by the spill was reduced from ~400 μg/L in the inflow to ~200 μg/L in the outflow by reservoir regulation. Moreover, reservoir regulation led to a high concentration of Sb in the reservoir sediment, which was difficult to remove and may cause subsequent unpredictable long-term ecological and health risks. In contrast, the Sb-enriched deposition inside the temporary dam was convenient to remove. Notably, temperature alternations between day and night in winter resulted in a large fluctuation in coagulation efficiency, which may cause the failure of stringent control projects. The results of this study suggest potential improvements to stringent control activities after mine tailing accidents to mitigate environmental impacts and prevent secondary risks.

[Curative effect analysis of the vestibular rehabilitation training on residual dizziness after successful canalith repositioning maneuvers in patients with benign paroxysmal positional vertigo]

Objective:To explore the curative effect and quality life of the vestibular rehabilitation training on residual dizziness after successful canalith repositioning maneuvers in patients with benign paroxysmal positional vertigo (BPPV). Method:Residual dizziness after successful canalith repositioning maneuvers in patients with BPPV were enrolled in our study. They were randomized into three groups, the control group A were no disposition which include 32 patients, the intervention group B were guided to self rehabilitation training which include 33 patients, the control group C were guided to Brandt Daroff training which include 33 patients. Dizziness handicap inventory (DHI) and residual dizziness duration were used to evaluation the patients. Result:After one week vestibular rehabilitation training, the scores of DHI in group B and C decreased, and there was no significant difference (P>0.05), there were significant differences between group B and group C in group A, respectively (P<0.01). After four weeks of vestibular rehabilitation training, the scores of DHI in group B and group C were lower than those in group A, the decrease of group B was significantly higher than that of group C (P<0.01). The residual dizziness duration indicated that no statistical differences in the B, C groups (P>0.05) and scores of group B,C were significantly lower than group A (P<0.05). Conclusion:The appropriate vestibular rehabilitation training on residual dizziness after successful canalith repositioning maneuvers in patients with BPPV can help promote the central vestibular compensation, reduce the residual symptoms, improve the quality life of patients, and which can be used as the adjuvant treatment on BPPV patient who has residual dizziness symptoms.

Functional interaction of Junctophilin 2 with small- conductance Ca2+ -activated potassium channel subtype 2(SK2) in mouse cardiac myocytes

Aim

Junctophilins (JPs), a protein family of the junctional membrane complex, maintain the close conjunction between cell surface and intracellular membranes in striate muscle cells mediating the crosstalk between extracellular Ca²⁺ entry and intracellular Ca²⁺ release. The small‐conductance Ca²⁺‐activated K⁺ channels are activated by the intracellular calcium and play an essential role in the cardiac action potential profile. Molecular mechanisms of regulation of the SK channels are still uncertain. Here, we sought to determine whether there is a functional interaction of junctophilin type 2 (JP2) with the SK channels and whether JP2 gene silencing might modulate the function of SK channels in cardiac myocytes.

Methods

Association of JP2 with SK2 channel in mouse heart tissue as well as HEK293 cells was studied using in vivo and in vitro approaches. siRNA knockdown of JP2 gene was assessed by real‐time PCR. The expression of proteins was analysed by Western blotting. Ca²⁺‐activated K⁺ current (I_K,Ca) in infected adult mouse cardiac myocytes was recorded using whole‐cell voltage‐clamp technique. The intracellular Ca²⁺ transient was measured using an IonOptix photometry system.

Results

We showed for the first time that JP2 associates with the SK2 channel in native cardiac tissue. JP2, via the membrane occupation and recognition nexus (MORN motifs) in its N‐terminus, directly interacted with SK2 channels. A colocalization of the SK2 channel with its interaction protein of JP2 was found in the cardiac myocytes. Moreover, we demonstrated that JP2 is necessary for the proper cell surface expression of the SK2 channel in HEK293. Functional experiments indicated that knockdown of JP2 caused a significant decrease in the density of I_K,Ca and reduced the amplitude of the Ca²⁺ transient in infected cardiomyocytes.

Conclusion

The present data provide evidence that the functional interaction between JP2 and SK2 channels is present in the native mouse heart tissue. Junctophilin 2, as junctional membrane complex (JMC) protein, is an important regulator of the cardiac SK channels.

Effect of feeding Rumen-protected capsule containing niacin, K2SO4, vitamin C, and gamma-aminobutyric acid on heat stress and performance of dairy cows

This study was conducted to evaluate the effects of supplemental rumen-protected capsule (RPC) on animal performance, serological indicators, and serum heat shock protein 70 (HSP70) of lactating Holstein cows under heat stress (HS). During summer months, 30 healthy multiparous lactating Holstein cows with a parity number of 3.1 ± 0.44, 70 ± 15 d in milk, an average body weight of 622 ± 62kg, and an average milk yield of 32.28 ± 0.96kg/d, were used. The cows were randomly allocated to two groups: a control group and an RPC-supplemented group (0.13373kg K₂SO₄, 0.02488kg vitamin C, 0.021148kg niacin, and 0.044784kggamma-aminobutyric acid per cow). During the 42-d experiment, ambient air temperature and relative humidity inside and outside the barn were recorded hourly every day for the determination of temperature-humidity index (THI). Milk and blood samples were collected every week, and body weight and body condition scoring were measured on day 0. Based on the THI values, the animals had moderate HS. On day 42, the RPC group had lower HSP70, adrenocorticotropic hormone (P = 0.0001), lactate dehydrogenase (P = 0.0338), and IL-6 (P = 0.0724) levels than the control group, with no significant differences in creatine kinase, glucocorticoid, or IL-2 levels. Milk yield, energy-corrected milk, and dry matter intake were higher in RPC than in the control group (P = 0.0196). There were no significant differences in milk fat or daily protein levels between the two groups; however, daily protein and milk fat levels were higher in the RPC group than in the control group (P = 0.0114 and P = 0.0665, respectively). Somatic cell counts were no different between the two groups. In conclusion, RPC may alleviate HS and improve dairy cow performance.

[Research progress of intervention strategies on voice disorders in children with vocal nodules]

Vocal nodules in children is one of the common diseases in children, characterized as the hoarse voice of the children, which is mainly due to improper use of sound long-term or excessive use of the voice. The hoarseness of children's voice undermine not only the physical and mental health of children, but also the quality of life of children and their families. In recent years, the incidence of vocal nodules in children has been increasing. There are considerable differences between the children's own characteristics and adults such as bronchial lumen and cognitive and cooperate aspects, which lead to a large number of difficulties for clinical diagnosis and intervention. Based on a large number of literatures, this paper reviews the risk factors, diagnosis, voice assessment and intervention strategies of vocal nodules in children, in order to provide more comprehensive reference for the medical workers.

[The research progress of OSAHS and cardiovascular disease]

Obstructive sleep apnea hypopnea syndrome(OSAHS) is characterized by recurrent stenosis or occlusion of upper airway during sleep. Although the controversy is far from over, this syndrome could often lead to different cardiovascular diseases(CVD) with those complicated pathophysiologic mechanisms, including hypertension, coronary heart disease, heart failure and cardiac arrhythmia. The objective of this article is to elaborate these related pathogenesis, and further to investigate the relationship between OSAHS and CVD. Besides, as one kind of effective and economical treatment, continuous positive airway pressure(CPAP) should be attached enough importance in the therapy of CVD with OSAHS.

Isolation and characterization of polymorphic EST-SSR and genomic SSR markers in spotted mandarin fish (Siniperca scherzeri Steindachne)

Spotted mandarin fish (Siniperca scherzeri Steindachne) feed solely on live fry of other fish species once the fry start feeding in the wild. In the present study, 26 polymorphic transcriptome-derived simple sequence repeat (SSR) markers and 14 genomic SSR markers were developed and characterized in S. scherzeri Steindachne by combining a biotin-enrichment protocol and transcriptome of F1 interspecies hybrids between S. chuatsi (♀) and S. scherzeri (♂). These 40 polymorphic SSRs amplified 168 alleles (mean 4.2). The number of alleles, observed heterozygosity, expected heterozygosity, and polymorphic information content per locus were in the range of 2 to 7 (mean 4.3), 0.1111 to 1.000 (mean 0.6718), 0.3118 to 0.8276 (mean 0.6901), and 0.2735 to 0.7902 (mean 0.6298), respectively. Ten of these microsatellite loci deviated significantly from Hardy-Weinberg equilibrium (P < 0.00125) after Bonferroni correction for multiple tests and no significant linkage disequilibrium (P < 0.00006) was observed. The microsatellite markers characterized from S. scherzeri could be a valuable tool in genetic evaluation for conservation and for assessment of the mechanism associated with unique food preference of S. scherzeri from a genetic point of view.

Relationship between genetic polymorphisms of DNA ligase 1 and non-small cell lung cancer susceptibility and radiosensitivity

The aim of this study was to examine the relationship between genetic polymorphisms in DNA ligase 1 (LIG1) and non-small cell lung cancer (NSCLC) susceptibility and radiosensitivity in a Chinese population. This was a case-control study that included 352 NSCLC patients and 448 healthy controls. Polymerase chain reaction-restriction fragment length polymorphism analysis was conducted to detect HaeIII polymorphisms in exon 6 of the LIG1 gene in this popula-tion. This information was used to observe the effects of radiation in pa-tients with different genotypes in order to determine the genotypes as-sociated with radiosensitivity. The CC genotype and C allele frequency were significantly higher in the NSCLC group than in the control group (P = 0.012 and P = 0.023, respectively). The relative risk of experienc-ing NSCLC was 2.55 [95% confidence interval (CI), 1.12-3.98] for CC homozygous patients and 0.87 (95%CI, 0.46-1.88) for AA homozygous patients. Analysis of LIG1 genetic polymorphisms and radiosensitiv-ity of NSCLC patients showed that AA homozygous patients were sig-nificantly more radiosensitive than the control group (AA vs AC, P = 0.014; AA vs CC, P < 0.001; AC vs CC, P = 0.023). Therefore, the LIG1 CC genotype was associated with susceptibility to NSCLC, and the AA genotype demonstrated increased radiosensitivity compared to the AC and CC genotypes.

A comparative study of locoregionally advanced nasopharyngeal carcinoma treated with intensity modulated irradiation and platinum-based chemotherapy

PURPOSE

To investigate the prognosis of three subgroups of locoregionally advanced nasopharyngeal carcinoma treated with intensity-modulated radiotherapy and platinum-based chemotherapy.

PATIENTS AND METHODS

Hundred and eighty-one consecutive patients with locoregionally advanced untreated nasopharyngeal carcinoma were retrospectively divided into three subgroups: locally advanced group (T3-4N0-1M0), regionally advanced group (T1-2N2-3M0) and the mixed group (T3-4N2-3M0). They were all treated with definitive intensity-modulated radiotherapy and platinum-based chemotherapy. Their prognosis were investigated and compared. Multivariate analysis was applied to identify the independent risk factors of study endpoints.

RESULTS

The 3-year locoregional control rates for locally advanced group, regionally advanced group, and the mixed group were 91.5%, 90.6% and 84.3% respectively, no significant difference was observed (P=0.656, P=0.429). The 3-year distant metastasis-free survival rates were 89.6%, 75.7% and 76.3%, respectively. The distant metastasis-free survival rate of the locally advanced group was significantly higher than the other two subgroups (P=0.028, P=0.028). The 3-year progression-free survival rates were 85.5%, 67.9% and 67.1% respectively with significance also favoring the locally advanced group (P=0.043, P=0.023). Nodal stage and the performance status were the independent risk factors of distant metastasis in the observed period.

CONCLUSIONS

In the context of intensity-modulated radiotherapy and platinum-based chemotherapy, the locally advanced group had a better prognosis compared with the regionally advanced group and the mixed group. Treatment stratification may be based on nodal stage.

Structure of nitrilotriacetate monooxygenase component B from Mycobacterium thermoresistibile

Mycobacterium tuberculosis belongs to a large family of soil bacteria which can degrade a remarkably broad range of organic compounds and utilize them as carbon, nitrogen and energy sources. It has been proposed that a variety of mycobacteria can subsist on alternative carbon sources during latency within an infected human host, with the help of enzymes such as nitrilotriacetate monooxygenase (NTA-Mo). NTA-Mo is a member of a class of enzymes which consist of two components: A and B. While component A has monooxygenase activity and is responsible for the oxidation of the substrate, component B consumes cofactor to generate reduced flavin mononucleotide, which is required for component A activity. NTA-MoB from M. thermoresistibile, a rare but infectious close relative of M. tuberculosis which can thrive at elevated temperatures, has been expressed, purified and crystallized. The 1.6 Å resolution crystal structure of component B of NTA-Mo presented here is one of the first crystal structures determined from the organism M. thermoresistibile. The NTA-MoB crystal structure reveals a homodimer with the characteristic split-barrel motif typical of flavin reductases. Surprisingly, NTA-MoB from M. thermoresistibile contains a C-terminal tail that is highly conserved among mycobacterial orthologs and resides in the active site of the other protomer. Based on the structure, the C-terminal tail may modulate NTA-MoB activity in mycobacteria by blocking the binding of flavins and NADH.

The prevalence of family childhood adversities and their association with first onset of DSM-IV disorders in metropolitan China

BACKGROUND

The prevalence of family childhood adversities (FCAs) and their joint effects on the first onset of subsequent mental disorders throughout the life course are rarely examined, especially in Asian communities.

METHOD

Face-to-face household interviews of 5201 people aged 18-70 years in Beijing and Shanghai were conducted by a multi-stage household probability sampling method. The first onsets of four broad groups of mental disorders and six categories of FCAs were assessed using The World Mental Health Composite International Diagnostic Interview (WMH-CIDI). Joint effects of FCAs were analyzed by the best fitting of several competitive multivariate models.

RESULTS

FCAs were highly prevalent and inter-correlated. Half of them were in a family-dysfunction cluster. The best-fitting model included each of six types of FCA (with family-dysfunction FCAs being the strongest predictors), number of family-dysfunction FCAs, and number of other FCAs. Family-dysfunction FCAs had a significant subadditive association with subsequent disorders. Little specificity was found for the effects of particular FCAs with particular disorders. Predictive effects of FCAs reached the highest in ages 13-24 compared to ages 4-12 and ≥ 25. Estimates of population-attributable risk proportions indicated that all FCAs together explained 38.5% of all first-onset disorders.

CONCLUSIONS

Chinese children were exposed to a broad spectrum of inter-related FCAs, as found in Western countries. FCAs related to family dysfunction were especially associated with subsequent mental disorders. Biological and/or environmental factors that mediate these long-term effects should be studied in prospective research on broad groups of FCAs.

Modeling oil spill trajectory in coastal waters based on fractional Brownian motion

This paper proposes a numerical method to simulate oil spill trajectories, which are affected by the combination of advection, turbulent diffusion and mechanical spreading process, based on a particle tracking algorithm. Recent studies have shown that the trajectories of drifters on the ocean surface have a fractal structure that is far from being described using ordinary Brownian motion. Thus, in modeling the diffusion process, a discrete method has been employed for the generation of fractional Brownian motion (fBm) to illustrate superdiffusive transport. The algorithm is implemented to predict oil slick trajectories following the "Arteaga" oil spill accident that occurred near the Dalian coastal region in 2005. When compared with the observed data and the results of traditional diffusion modeling, the numerical results based on the fBm model are encouraging.

A numerical oil spill model based on a hybrid method

The purpose of this paper is the development of a hybrid particle tracking/Eulerian-Lagrangian approach for the simulation of spilled oil in coastal areas. Oil discharge from the source is modeled by the release of particles. When the oil slick thickness or the oil concentration reaches a critical value, particles are mapped on slick thickness or node concentrations, and the calculations proceed in the Eulerian-Lagrangian mode. To acquire accurate environment information, the model is coupled with the 3-D free-surface hydrodynamics model (POM) and the third-generation wave model (SWAN). By simulating the oil processes of spreading, advection, turbulent diffusion, evaporation, emulsification, dissolution and shoreline deposition, it has the ability to predict the horizontal movement of surface oil slick, the vertical distribution of oil particles, the concentration in the water column and the mass balance of spilled oil. An accidental oil release near Dalian coastal waters is simulated to validate the developed model. Compared with the satellite images of oil slicks on the surface, the numerical results indicate that the model has a reasonable accuracy.

Structural analysis of anti-tumor heteropolysaccharide GFPS1b from the cultured mycelia of Grifola frondosa GF9801

A 21-kDa heteropolysaccharide, coded as GFPS1b, was obtained from the cultured mycelia of Grifola frondosa GF9801 by hot-water extraction, ethanol precipitation, and fractioned by DEAE Sepharose Fast-flow, followed by the purification with Sephadex G-100 column chromatography using an AKTA purifier. It exhibited more potent anti-proliferative activity on MCF-7 cells than other polysaccharide fractions. GFPS1b was an acidic polysaccharide with approximately 16.60% protein and 4.3% uronic acid. Gas chromatography of absolute acid hydrolysate of GFPS1b suggested that it was composed of D-glucose, D-galactose, and L-arabinose with a molar ratio of 4:2:1. Periodate oxidation, Smith degradation, partial acid hydrolyzation, methylation analysis, FT-IR, and (1)H, (13)C NMR spectroscopy analysis revealed that GFPS1b had a backbone consisting of alpha-(1-->4)-linked D-galacopyranosyl and alpha-(1-->3)-linked D-glucopyranosyl residues substituted at O-6 with glycosyl residues composed of alpha-L-arabinose-(1-->4)-alpha-D-glucose (1--> linked residues.

Reversal effects of droloxifene on multidrug resistance in adriamycin-resistant K562 cell line

AIM

To study the reversal effects of droloxifene (DRO) on multidrug resistance (MDR) in K562 cell line resistant to adriamycin (ADR).

METHODS

K562 cell line resistant to ADR (K562/A02) and K562 cell line sensitive to ADR (K562) were treated with DRO. Using MTT assay, chemosensitivity to ADR in DRO-treated K562 cell lines was studied. Before and after the treatment with DRO 10 micromol/L, MDR1 and GSTpi gene expression were assayed by reverse transcription-polymerase chain reaction and immunocytochemistry assay. Flow cytometry was used to determine intracellular ADR concentration.

RESULTS

DRO significantly reversed MDR in K562/A02 (P < 0.01). After treatment of DRO 20, 10, and 5 micromol/L, the chemosensitivity to ADR was increased to 14, 13, and 4 folds, respectively. The reversal activity of DRO was similar to that of verapamil (VRP). After treated with DRO 10 micromol/L, both MDR1 and GSTpi mRNA expression began to decline on the 2nd day, and significantly decreased on the 5th day (P<0.01). The changes in P-gp and GSTpi protein expression were similar to that of their mRNA expression. Two hours after treatment of DRO 20, 10, and 5 micromol/L, intracellular ADR concentration in K562/A02 was increased to 2.9, 2.3, and 1.5 folds, respectively. However, DRO did not markedly increase ADR accumulation in K562.

CONCLUSION

DRO had strong reversal effect on MDR in K562/A02, which was comparable to that of VRP, but the reversal effect was via different pathways.

Genetic progression and heterogeneity associated with the development of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma is a common fatal cancer, and Shanxi province, a region in north-central China, has some of the highest esophageal cancer rates in the world. Chromosomal regions with frequent allelic loss may point to major susceptibility genes that will assist us in understanding the molecular events involved in esophageal carcinogenesis and may serve as the basis for the development of markers for genetic susceptibility and screening for early detection of this cancer. This study was designed to identify events in the molecular progression of precursor and invasive lesions of squamous esophageal cancer. Twelve marker loci identified during our previous studies as having some of the highest rates of loss of heterozygosity (LOH) in invasive esophageal cancer were evaluated in laser-microdissected DNA obtained from low- and high-grade dysplastic lesions and invasive tumor foci from 10 fully embedded esophageal resection specimens. Each resection specimen contained a spectrum of disease, from epithelium that appeared histologically normal to invasive cancer, including a single dominant tumor surrounded by a region of precursor lesions (low- and high-grade dysplasia) and occasional "remote," nonadjacent precancerous foci. Using the 12 polymorphic markers, LOH was found in all of the three stages of disease. The frequency of LOH for all of the markers together increased with increasing disease severity. Among the informative low-grade dysplasia samples, LOH was detected with markers D3S1766 (3p), D4S2632 (4p), D9S910 (9q), and D13S1493 (13q), suggesting that LOH at these loci may be associated with early stages of tumor initiation and/or progression. LOH was detected among the informative high-grade (but not low-grade) dysplasia samples for the other eight markers tested, suggesting that LOH at these loci may occur later in the neoplastic process. In addition to the association between disease progression and these genetic changes, considerable genetic heterogeneity was found in each fully embedded resection specimen both between and within geographically separate neoplastic lesions.

Nuclear stopping as a probe for in-medium nucleon-nucleon cross sections in intermediate energy heavy ion collisions

Using an isospin-dependent quantum molecular dynamics, nuclear stopping in intermediate heavy ion collisions has been studied. The calculation has been done for colliding systems with different neutron-proton ratios in beam energy ranging from 15 MeV/ u to 150 MeV/ u. It is found that, in the energy region from above Fermi energy to 150 MeV/ u, nuclear stopping is very sensitive to the isospin dependence of in-medium nucleon-nucleon cross section, but insensitive to symmetry potential. From this investigation, we propose that nuclear stopping can be used as a new probe to extract the information on the isospin dependence of in-medium nucleon-nucleon cross section in intermediate energy heavy ion collisions.

Reversal effects of nomegestrol acetate on multidrug resistance in adriamycin-resistant MCF7 breast cancer cell line

BACKGROUND

Chemotherapy is important in the systematic treatment of breast cancer. To enhance the response of tumours to chemotherapy, attention has been focused on agents to reverse multidrug resistance (MDR) and on the sensitivity of tumour cells to chemical drugs. Hundreds of reversal drugs have been found in vitro, but their clinical application has been limited because of their toxicity. The reversal activity of progestogen compounds has been demonstrated. However, classical agents such as progesterone and megestrol (MG) also have high toxicity. Nomegestrol (NOM) belongs to a new derivation of progestogens and shows very low toxicity. We studied the reversal activity of NOM and compared it with that of verapamil (VRP), droloxifene (DRO), tamoxifen (TAM) and MG, and investigated the reversal mechanism, i.e. effects on the expression of the MDR1, glutathione S-transferase Pi (GSTpi), MDR-related protein (MRP) and topoisomerase IIalpha (TopoIIalpha) genes, as well as the intracellular drug concentration and the cell cycle. The aim of the study was to examine the reversal effects of NOM on MDR in MCF7/ADR, an MCF7 breast cancer cell line resistant to adriamycin (ADR), and its mechanism of action.

METHODS

MCF7/ADR cells and MCF7/WT, an MCF7 breast cancer cell line sensitive to ADR, were treated with NOM as the acetate ester. With an assay based on a tetrazolium dye [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide; MTT], the effects of various concentrations of NOM on MDR in MCF7/ADR cells were studied. Before and after the treatment with 5 microM NOM, the expression of the MDR-related genes MDR1, GSTpi, TopoIIalpha and MRP were assayed with a reverse transcriptase polymerase chain reaction (RT-PCR) immunocytochemistry assay. By using flow cytometry (FCM), we observed the intracellular ADR concentration and the effects of combined treatment with NOM and ADR on the cell cycle. Results collected were analysed with Student's t test.

RESULTS

NOM significantly reversed MDR in MCF7/ADR cells. After treatment NOM at 20, 10 and 5 microM, chemosensitivity to ADR increased 21-fold, 12-fold and 8-fold, respectively. The reversal activity of NOM was stronger than that of the precursor compound MG, and comparable to that of VRP. After treatment with 5 microM NOM, the expression of both the MDR1 and the GSTpi mRNA genes began to decline on the second day (P <0.05 and P <0.01, respectively), and reached the lowest level on the third day (both P <0.01); however, on the fifth day the expression levels began to increase again (both P <0.05). The expression of MRP and TopoIIalpha had no significant changes. Changes in the expression of P-glycoprotein (P-gp) and GSTpi were similar to those of their mRNA expressions, showing early declines and late increases. Two hours after treatment with 20, 10 and 5 microM NOM, the intracellular ADR concentration increased 2.7-fold, 2.3-fold and 1.5-fold respectively. However, NOM did not increase ADR accumulation in MCF7/WT cells. FCM data showed that after 48 h of combined administration of NOM (20 microM) and ADR (from low to high concentration), MCF7/ADR cells showed a gradual arrest at the G2M phase with increasing ADR dose. The arrest effect with combined drug treatment was stronger than that with the single ADR treatment.

CONCLUSION

MDR is the major mechanism of drug resistance in malignant tumour cells. To overcome MDR and to increase chemosensitivity, many reversal agents have been found. Most progestogen compounds have been demonstrated to have reversal effects, but we found no data on NOM, a new progestogen compound. Our results show that NOM has strong reversal activity. The reversal effects were stronger than those of the precursor compound, MG, and were comparable to that of VRP. Because NOM has low toxicity, it might have good prospects in clinical application. Using RT-PCR and immunocytochemistry assays, we studied the effects of NOM on MDR-related genes. The results were that NOM could markedly downregulate the mRNA and protein expression levels of MDR1 and GSTpi. TopoIIalpha and MRP gene expression showed no significant changes. It is known that P-gp induces MDR in tumour cells mainly by decreasing the intracellular drug concentration. After treatment with NOM, the intracellular drug concentration in MCF7/ADR cells increased significantly. Combined treatment with NOM and ADR induced arrest at the G2M phase. It is worth noting that NOM caused an early decrease and a late increase in the expression of some MDR-related genes in a time-dependent manner. The phenomena raise a question for the continued administration of reversal agents in clinics that merits further study. We demonstrate that NOM has strong reversal effects on MDR in MCF7/ADR cells. The reversal is via different routes, namely downregulating the mRNA and protein expression levels of MDR1 and GSTpi, increasing intracellular drug concentration and arresting cells at the G2M phase (NOM in combination with ADR). The reversal mechanism needs further study.

Evaluation of combined therapy with chemoembolization and irradiation for large hepatocellular carcinoma

The effects of combined transcatheter arterial chemoembolization (TACE) and radiotherapy in patients with large hepatocellular carcinoma (HCC) were analysed retrospectively. A total of 107 patients with large unresectable HCC was treated with TACE followed by external beam irradiation. The largest dimension of the tumours ranged from 5 cm to 18 cm. Acute effects, survival rates, toxicity and prognostic factors were analysed. Follow-up ranged from 4 months to 98 months (median 24 months). An objective response, i.e. reduction of tumour area greater than 50%, was achieved in 48.6% of cases. In 64.9% of the cases with increased alpha-feto protein (AFP) values, AFP level underwent a reduction of more than 25%. The cumulative survival rates at 1, 3 and 5 years were 59.4%, 28.4% and 15.8%, respectively (median survival 18 months). The combination therapy was generally well tolerated. Only two patients died from liver failure or variceal bleeding associated with therapy. The Cox proportional hazards model showed that the number of tumours and the irradiation dose were independent prognostic factors. The results indicate that combined TACE with radiotherapy is a promising therapeutic approach for large unresectable HCC. Prospective controlled trials to ascertain the real potential benefit of this approach are required.

Clinical and cytogenetic findings in seven cases of inverted duplication of 8p with evidence of a telomeric deletion using fluorescence in situ hybridization

We report on the clinical and cytogenetic findings in 7 cases of inverted duplication of region 8p11.2p23. The phenotype of inv dup (8p) compiled from this series and the literature (N = 29) consists of severe mental retardation (100%), minor facial alterations (97%), agenesis of the corpus callosum (80%), hypotonia (66%), orthopedic abnormalities (58%), scoliosis/kyphosis (40%), and congenital heart defect (26%). A telomeric deletion of region 8p23.3-pter was confirmed in 3 of our cases studied using fluorescent in situ hybridization with a telomeric probe for 8p. Thus, these karyotypes are inv dup del(8) (qter-->p23.1::p23.1-->p11.2:). Our findings suggest that most cases of inv dup(8p) probably have a telomeric deletion.

Detection of single-stranded DNA damage using monoclonal anti-thymidine antibody

A method to detect single-stranded DNA damage from individual cells has been developed using a monoclonal anti-thymidine antibody (MoAb20B7). Initially, HL-60 cells were incubated with daunomycin at different concentrations, and processed by MoAb20B7. While 73.5% of the cells incubated with 5 micrograms/ml of daunomycin for 24 h reacted positively with MoAb20B7, 83.5% cells at 10 micrograms/ml daunomycin dose were positive. Next, this method was combined with unscheduled DNA synthesis to simultaneously measure repair and damage from individual cells. Finally, patients with acute myeloid leukemias were studied before and 24 h after therapy with a daunomycin containing regimen. In vivo damage could be determined in a prompt fashion.

Rat intestinal trehalase. Studies of the active site

Rat intestinal trehalase was solubilized, purified and reconstituted into proteoliposomes. With octyl glucoside as the solubilizing detergent, the purified protein appeared as a single band on SDS/polyacrylamide-gel electrophoresis with an apparent molecular mass of 67 kDa. Kinetic studies indicated that the active site of this enzyme can be functionally divided into two adjacent regions, namely a binding site (with pKa 4.8) and a catalytic site (with pKa 7.2). Other findings suggested that the catalytic site contains a functional thiol group, which is sensitive to inhibition by N-ethylmaleimide, Hg2+ and iodoacetate. Substrate protection and iodoacetate labelling of the thiol group demonstrated that only a protein of 67 kDa was labelled. Furthermore, sucrose and phlorizin protected the thiol group, but Tris-like inhibitors did not. Structure-inhibition analysis of Tris-like inhibitors, the pH effect of Tris inhibition and Tris protection of 1-(3-dimethylaminopropyl)-3-ethylcarbodi-imide inactivation permitted characterization and location of a separate site containing a carboxy group for Tris binding, which may also be the binding region. On the basis of these findings, a possible structure for the active site of trehalase is proposed.