[A case of acute respiratory distress syndrome induced by inhalation of hydrogen chloride]

Poisoning induced by inhalation of hydrogen chloride has significant effects on the respiratory system. It can cause severe pulmonary edema and acute respiratory distress syndrome (ARDS) in the early stage, and even death in critical cases. As a novel treatment for ARDS, the efficacy of sivelestat sodium in infection-induced ARDS has been widely verified, but its application in ARDS caused by chemical poisoning is still scarce in literature. Here we report a case of ARDS induced by hydrogen chloride inhalation which was successfully treated with sivelestat sodium and conventional treatment.

[Establishment and validation of prognosis predictive model using m6A RNA methylation regulators in children acute myeloid leukemia]

Objective: To figure out the association between the expression of m⁶A RNA methylation regulators and the prognosis of children AML, and provide genetic markers for monitoring the progression and recurrence of AML. Methods: Twenty two m⁶A RNA methylation regulators were firstly analyzed using the data from Therapeutically Applicable Research To Generate Effective Treatments(TARGET) database and The Genotype-Tissue Expression(GTEx) database, Wilcoxon rank test was performed to analyze the differentially expression of m⁶A RNA methylation regulators between the AML and normal tissue, 296 AML children were divided into training cohort and validation cohort by simple random sampling method, Lasso regression was used to screen out the risk factors and the multivariate Cox regression was applied for establishing prognosis predicting model in training cohort. Kaplan-Meier survival curve, time-dependent ROC curve and multivariate Cox regression were used to estimate the efficiency of risk score calculated by predictive model in validation cohort. Results: Twenty one m⁶A genes were up regulated in AML compared to Normal patients. Five m⁶A RNA methylation regulators(ZC3H13, YTHDC2, HNRNPA2B1, METTL3, METTL5) were included in final predicting model. Risk score could independently predict the survival of AML patients in training cohort(HR:2.72, 95%CI: 1.54-4.81, P=0.000 6) and validation cohort(HR:2.01, 95%CI:1.14-3.50, P=0.016). Low-risk patients had better prognoses than high-risk patients both in training cohort(P=0.001 9) and validation cohort(P=0.023). Conclusion: This prognosis predicting model constructed by m⁶A RNA methylation regulators could independently predict the survival prognosis in AML children, and should be helpful for clinical therapy.

The invasion status of lymphovascular space and lymph nodes in cervical cancer assessed by mono-exponential and bi-exponential DWI-related parameters

AIM

To investigate whether mono-exponential and bi-exponential diffusion-weighted imaging (DWI)-related parameters of the primary tumour can evaluate the status of lymphovascular space invasion (LVSI) and lymph node metastasis (LNM) in patients with cervical carcinoma preoperatively.

MATERIALS AND METHODS

Eighty patients with cervical carcinoma were enrolled, who underwent preoperative multi b-value DWI and radical hysterectomy. They were classified into LVSI(+) versus LVSI(-) and LNM(+) versus LNM(-) according to postoperative pathology. The apparent diffusion coefficient (ADC), pure molecular diffusion (D), pseudo-diffusion coefficient (D∗), and perfusion fraction (f) were calculated from the whole tumour (__whole) and tumour margin (__margin). All parameters were compared between LVSI(+) and LVSI(-) and between LNM(+) and LNM(-). Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were performed to evaluate the diagnostic performance of these parameters.

RESULTS

f__margin and D∗__whole showed significant differences in differentiating LVSI(+) from LVSI(-) tumours (p=0.002, 0.008, respectively), while LNM(+) tumours presented with significantly higher ADC__margin than that of LNM(-) tumours (p=0.009). The other parameters were not independent related factors with the status of LVSI or LNM according to logistic regression analysis (p>0.05). The area under the ROC curve of f__margin combined with D∗__whole in discriminating LVSI(+) from LVSI(-) was 0.826 (95% confidence interval [CI]: 0.691-0.961), while ADC__margin in differentiating LNM(+) from LNM(-) was 0.788 (95% CI: 0.648-0.928).

CONCLUSIONS

The parameters generated from mono-exponential and bi-exponential DWI of the primary cervical carcinoma could help discriminate its status regarding LVSI (f__margin and D∗__whole) and LNM (ADC__margin).

[Spectrometric analyses of larotaxel and larotaxel liposomes quantification by high performance liquid chromatography]

OBJECTIVE

Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes.

METHODS

The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes.

RESULTS

The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 μm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%.

CONCLUSION

The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.

Succession Law of Intestinal Flora after Death in SD Rats

OBJECTIVES

To initially explore the sequential changes in the intestinal flora of corpse for the estimation of postmortem interval （PMI）.

METHODS

Rats were sacrificed by cervical dislocation, and samples were taken from their intestines using cotton swab to extract the DNA of intestinal flora. The 16S rRNA V3 universal primers were selected for PCR, and the PCR products were used for denatured gradient gel electrophoresis. The diversity and similarity analysis of intestinal flora were analyzed between groups, and the bands were cut from denaturing gradient gel electrophoresis. After purification, PCR and sequencing, the percentage of major bacteria in each group was obtained.

RESULTS

The flora diversity showed a reduced tendency from 1st to 30th day after death （ P<0.05）, while the intra-group similarity showed a downward trend （ P<0.05）. The number of bands and intra-group similarity coefficient （Cs） on the first day was higher than that of other groups （ P<0.05）. The intra-group Cs of the 25th and 30th day had a significant difference compared with the 5th day （ P<0.05）. At the genus level, the intestinal flora was mainly composed of Enterococcus sp. on the 1th and 5th day after death, Bacillus thuringienssis was the dominant species on the 10th, 15th and 20th day, and Enterococcus faecalis became the dominant species on the 25th and 30th day.

CONCLUSIONS

The composition and structure of intestinal flora change significantly in rats with the time after death, which indicates that the succession of intestinal flora is related to the postmortem interval.

Current Research and Prospects on Postmortem Interval Estimation

The researches on postmortem interval （PMI） estimation are very important and meaningful in forensic science. PMI estimation is also an important issue that must be solved in practice of forensic pathology. There are many defects existing in traditional methods for PMI estimation, so it is imperative to introduce new pathways. With the emergence of various new technologies, the researches on PMI estimation have a tendency from simple to complex with a growth of data. The present review firstly summarizes a series of methods used for PMI estimation, and then gives an outlook for the application of artificial intelligence algorithms in this field.

Association of TCF7L2 gene polymorphisms with susceptibility to type 2 diabetes mellitus in a Chinese Hui population

Diabetes is one of costly chronic diseases. Previous studies across several ethnicities have shown that polymorphisms in the transcription factor 7-like 2 (TCF7L2) gene were strongly associated with susceptibility to type 2 diabetes (T2DM). In the present study, the association between the TCF7L2 gene and the susceptibility to T2DM in a Chinese Hui population was interrogated. Polymerase chain reaction (PCR)- restriction fragment length polymorphism analysis and allelic specific PCR were employed for examining the TCF7L2 gene rs12255372 (G>T) and rs290487 (C>T), and rs7901695 (T>C) polymorphisms, respectively, in 109 healthy individuals and 111 subjects with T2DM who were of Chinese Hui descent and lived in the Ningxia Hui Autonomous Region of China. The results showed that the genotypic frequency of rs290487 and the allelic frequency distributions of the rs7901695 and rs290487 loci were not significantly different between patients and controls in this population. However, both the genotypic and the allelic frequencies at rs12255372 exhibited statistical differences between the patients with T2DM and the unaffected cohort (P < 0.01). In addition, the frequency of the G allele at the rs12255372 locus in the patients was higher than that in healthy individuals (OR = 1.198, 95%CI = 1.097-1.307). These findings suggest that the TCF7L2 rs12255372 (G>T) polymorphism might be one of the most important genetic factors associated with T2DM susceptibility, and that individuals in the Chinese Hui population who carry a G allele at this locus might be at risk to develop T2DM.

Association of VDR polymorphisms with type 2 diabetes mellitus in Chinese Han and Hui populations

We investigated the association between vitamin D receptor (VDR) and susceptibility to type 2 diabetes mellitus (T2DM). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was conducted to examine single nucleotide polymorphisms (SNPs) of the rs1544410 (BsmI, G>A), rs757343 (Tru9I, G>A), rs731236 (TaqI, T>C), and rs739837 (BglI, G>T) loci of the VDR gene in 334 healthy individuals (Hui 115, Han 219) and 355 T2DM patients (Hui 154, Han 201) living in the Ningxia Hui Autonomous Region of China. The genotypic frequency and allelic frequency distributions in the VDR gene showed no significant difference between T2DM patients and controls in the Chinese Hui population. However, statistical differences in the genotypic frequency at rs739837 and in the genotypic and allelic frequencies at rs1544410 were observed between T2DM patients and controls in the Chinese Han population (P < 0.05). Patient-control haplotype analyses using the SHEsis online haplotype analysis software showed that the G allele frequency of rs1544410 in the T2DM group was higher than that in the control group [odds ratio (OR) = 1.738, 95% confidence interval (CI) = 1.055-2.865], suggesting that the G allele is a risk factor of T2DM in the Chinese Han population. The frequency of haplotype GGCT between cases and controls was significantly different in both Chinese Hui [OR (95%CI) = 4.714 (1.04-21.36)] and Han populations [OR (95%CI) = 1.723 (1.03-2.883)] (P < 0.05), implying that the haplotype GGCT of the VDR gene is associated with susceptibility to T2DM in these ethnicities.

Polymorphisms of +2836 G>A in the apoE gene are strongly associated with the susceptibility to essential hypertension in the Chinese Hui population

In the present study, the correlation of polymorphisms of the apolipoprotein E (apoE) gene with the susceptibility of essential hypertension (EH) was investigated. Single nucleotide polymorphisms of the apoE gene at the -491 A>T, +969 C>G, and +2836 G>A sites were determined in 221 non-EH individuals and 109 subjects with EH of Chinese Hui ethnicity using polymerase chain reaction-restriction fragment length polymorphism analysis. The results showed that neither the genotypic frequency nor the allelic frequency at the -491 A>T and +969 C>G sites exhibited a statistically significant difference between these two groups (P > 0.05). However, a significant difference was observed in genotypic frequency and allelic frequency at the +2836 G>A site between EH patients and non-EH individuals (P < 0.01). In addition, a significantly higher frequency of the A allele at the +2836 G>A site was also detected in EH patients (83%) compared with controls (47.5%) (P < 0.01; OR = 4.82, 95%CI = 3.25-7.17); in contrast, the frequency of the G allele at the +2836 G>A site was significantly lower (17%) in the patient group in comparison with the non-EH cohorts (52.5%) (P < 0.01; OR = 0.21, 95%CI = 0.14-0.31). These results suggest that the polymorphism at the +2836 G>A site in the apoE gene is strongly correlated with the susceptibility to EH in the Chinese Hui ethnic population.

Polymorphisms of rs1799983 (G>T) and rs1800780 (A>G) of the eNOS gene associated with susceptibility to essential hypertension in the Chinese Hui ethnic population

We investigated a possible association of polymorphism of the eNOS gene and essential hypertension in the Chinese Hui population; polymorphisms of rs2070744 (T>C), rs1799983 (G>T), rs1800780 (A>G), and rs3918181 (A>G) loci of the eNOS gene were examined. We found that the genotypic frequencies at rs1799983 and rs1800780 loci differed significantly between patients with essential hypertension and control cohorts. The allelic frequency of the rs1799983 locus also differed significantly between essential hypertension patients and non-essential hypertension controls in this population. Additionally, the G allele of the rs1799983 locus was less frequent in the essential hypertension patients than in controls, with an odds ratio (OR) value of 3.851 [95% confidence interval (95%CI) = 2.236-6.631]. This is an indication of a protective factor of essential hypertension in Chinese Hui people. Haplotype analysis using the 4 SNPs revealed 15 haplotypes. Haplotype frequencies of CGAG, TTAG, TGGG, TTGG, and TTGA were significantly different in essential hypertension patients compared to non-essential hypertension controls. Individuals with haplotypes CGAG [χ² = 7.371, OR (95%CI) = 0.352 (0.161-0.770)] and TGGG [χ² = 6.180, OR (95%CI) = 0.600 (0.400- 0.899)] appear less likely to have essential hypertension. However, Chinese Hui with the haplotype TTAG are at risk to develop essential hypertension [χ² = 10.816, OR (95%CI) = 2.689 (1.466-4.932)]. We conclude that polymorphism of the eNOS gene is associated with susceptibility to essential hypertension in the Chinese Hui population.

Comparison of carotid atherosclerotic plaque characteristics by high-resolution black-blood MR imaging between patients with first-time and recurrent acute ischemic stroke

BACKGROUND AND PURPOSE

It has been shown that patients with a first ischemic stroke are at high risk of developing recurrent stroke due to carotid atherosclerotic plaque rupture. However, no one has defined the difference in plaques between initial and recurrent stroke. This study sought to investigate the characteristics of carotid plaque between patients with first-time and recurrent acute ischemic stroke by using MR imaging.

MATERIALS AND METHODS

Eighty-nine patients with recent acute ischemic stroke were recruited. All subjects underwent carotid high-resolution black-blood MR imaging. The index carotid arteries, defined as the arteries responsible for the ipsilateral stroke, were analyzed quantitatively and qualitatively. Carotid plaque burden and compositional features between patients with first-time and recurrent ischemic stroke were compared.

RESULTS

Of 89 recruited patients, 51 had first-time stroke and 38 had recurrent stroke. The mean WA, WT, and PWV were greater in patients with recurrent stroke than in patients with first-time stroke (all, P < .05). Compared with patients with first-time stroke, those with recurrent stroke showed significantly higher prevalence of calcification (44.7% versus 23.5%, P = .035) as well as a larger volume of LRNC (179.14 ± 254.81 mm(2) versus 71.65 ± 111.15 mm(2), P = .027). IPH or fibrous cap rupture or both were observed in 15.8% of patients with recurrent stroke and 3.9% of patients with first-time stroke.

CONCLUSIONS

Carotid plaques in patients with recurrent ischemic stroke are significantly aggravated compared with those in patients with first-time stroke, and monitoring carotid plaques in patients with initial stroke by MR imaging may be helpful for secondary stroke prevention.

Polymorphisms of the TIM-1 gene are associated with rheumatoid arthritis in the Chinese Hui minority ethnic population

The T-cell immunoglobulin and mucin domain 1 (TIM-1) is known to be associated with susceptibility to rheumatoid arthritis (RA). We investigated the association of four single-nucleotide polymorphisms (SNPs) in the promoter region of the TIM-1 gene with susceptibility to RA in a Chinese Hui ethnic minority group. Using RFLP or sequence specific primer-PCR, 118 RA patients and 118 non-arthritis control individuals were analyzed for the -1637A>G, -1454G>A, -416G>C, and -232A>G SNPs in the TIM-1 gene. The polymorphisms -232A>G and -1637A>G in the promoter region of TIM-1 were found to be associated with susceptibility to the RA gene in the Hui population, while -416G>C and -1454G>A SNPs were not. Of these, the polymorphism of -232A>G is inconsistent with that found in a Korean population, suggesting that genetic variations of the TIM-1 gene contribute to RA susceptibility in different ways among different populations. Based on haplotype analysis, individuals with haplotypes AGCA (Χ(2) = 22.0, P < 0.01, OR (95%CI) >1), AGCG (Χ(2) = 18.16, P < 0.01, OR (95%CI) >1) and AGGA (Χ(2) = 5.58, P < 0.05, OR (95%CI) >1) are at risk to develop RA in the Chinese Hui population; those with the GAGA (Χ(2) = 7.44, P < 0.01, OR (95%CI) <1) haplotype may have a decreased likelihood of RA. GGCA and GGCG are more common in both RA and non-RA subjects. We conclude that -1637A>G and -232A>G polymorphisms of TIM-1 are associated with susceptibility to RA in the Chinese Hui population.

Magnetic resonance lymphography at 3T: a promising noninvasive approach to characterise inguinal lymphatic vessel leakage

PURPOSE

To explore the feasibility of using 3T high-resolution MR lymphangiography to characterize inguinal lymphatic vessel leakage (LVL).

MATERIALS AND METHODS

Sixteen patients with known inguinal LVL underwent 3T MR lymphangiography and T(2)-weighted imaging. The presence or absence of inguinal LVL and the responsible lymphatic vessels were determined using the above imaging modalities and confirmed by surgical procedure. Afterwards, fifteen patients with recurring LVL following conservative treatment were referred to surgical intervention.

RESULTS

Specific inguinal LVL enhancement patterns and leaking lymphatic vessels were detected in 15 of 16 patients. Compared to the SNR of enhanced lymph nodes, that of the enhanced LVL was significantly greater (t = 7.149, p < 0.01), thereby making it possible to differentiate between LVL sites and enhancing inguinal lymph nodes. Furthermore, the steepest contrast enhancement curve slope of enhanced LVL was lower than that of enhanced lymph nodes (t = -2.860, p = 0.02). After MR diagnosis, 15 patients successfully underwent open exploration and ligation of the leaking lymphatic vessel. Clinical follow-up did not demonstrate recurrence of lymphatic fluid in the groin.

CONCLUSIONS

High-resolution MR lymphangiography combined with T(2)-weighted imaging is a promising approach to identifying specific features of lymphatic vessel leakage in the groin.

RAS2 regulates growth and pathogenesis in Fusarium graminearum

Fusarium graminearum is a ubiquitous pathogen of cereal crops, including wheat, barley, and maize. Diseases caused by F. graminearum are of particular concern because harvested grains frequently are contaminated with harmful mycotoxins such as deoxynivalenol (DON). In this study, we explored the role of Ras GTPases in pathogenesis. The genome of F. graminearum contains two putative Ras GTPase-encoding genes. The two genes (RAS1 and RAS2) showed different patterns of expression under different conditions of nutrient availability and in various mutant backgrounds. RAS2 was dispensable for survival but, when disrupted, caused a variety of morphological defects, including slower growth on solid media, delayed spore germination, and significant reductions in virulence on wheat heads and maize silks. Intracellular cAMP levels were not affected by deletion of RAS2 and exogenous treatment of the ras2 mutant with cAMP did not affect phenotypic abnormalities, thus indicating that RAS2 plays a minor or no role in cAMP signaling. However, phosphorylation of the mitogen-activated protein (MAP) kinase Gpmk1 and expression of a secreted lipase (FGL1) required for infection were reduced significantly in the ras2 mutant. Based on these observations, we hypothesize that RAS2 regulates growth and virulence in F. graminearum by regulating the Gpmk1 MAP kinase pathway.

Map kinases in fungal pathogens

MAP kinases in eukaryotic cells are well known for transducing a variety of extracellular signals to regulate cell growth and differentiation. Recently, MAP kinases homologous to the yeast Fus3/Kss1 MAP kinases have been identified in several fungal pathogens and found to be important for appressorium formation, invasive hyphal growth, and fungal pathogenesis. This MAP kinase pathway also controls diverse growth or differentiation processes, including conidiation, conidial germination, and female fertility. MAP kinases homologous to yeast Slt2 and Hog1 have also been characterized in Candida albicans and Magnaporthe grisea. Mutants disrupted of the Slt2 homologues have weak cell walls, altered hyphal growth, and reduced virulence. The Hog1 homologues are dispensable for growth but are essential for regulating responses to hyperosmotic stress in C. albicans and M. grisea. Overall, recent studies have indicated that MAP kinase pathways may play important roles in regulating growth, differentiation, survival, and pathogenesis in fungal pathogens.

The BMP1 gene is essential for pathogenicity in the gray mold fungus Botrytis cinerea

In Magnaporthe grisea, a well-conserved mitogen-activated protein (MAP) kinase gene, PMK1, is essential for fungal pathogenesis. In this study, we tested whether the same MAP kinase is essential for plant infection in the gray mold fungus Botrytis cinerea, a necrotrophic pathogen that employs infection mechanisms different from those of M. grisea. We used a polymerase chain reaction-based approach to isolate MAP kinase homologues from B. cinerea. The Botrytis MAP kinase required for pathogenesis (BMP) MAP kinase gene is highly homologous to the M. grisea PMK1. BMP1 is a single-copy gene. bmp1 gene replacement mutants produced normal conidia and mycelia but were reduced in growth rate on nutrient-rich medium. bmp1 mutants were nonpathogenic on carnation flowers and tomato leaves. Re-introduction of the wild-type BMP1 allele into the bmp1 mutant restored both normal growth rate and pathogenicity. Further studies indicated that conidia from bmp1 mutants germinated on plant surfaces but failed to penetrate and macerate plant tissues. bmp1 mutants also appeared to be defective in infecting through wounds. These results indicated that BMP1 is essential for plant infection in B. cinerea, and this MAP kinase pathway may be widely conserved in pathogenic fungi for regulating infection processes.

Independent signaling pathways regulate cellular turgor during hyperosmotic stress and appressorium-mediated plant infection by Magnaporthe grisea

The phytopathogenic fungus Magnaporthe grisea elaborates a specialized infection cell called an appressorium with which it mechanically ruptures the plant cuticle. To generate mechanical force, appressoria produce enormous hydrostatic turgor by accumulating molar concentrations of glycerol. To investigate the genetic control of cellular turgor, we analyzed the response of M. grisea to hyperosmotic stress. During acute and chronic hyperosmotic stress adaptation, M. grisea accumulates arabitol as its major compatible solute in addition to smaller quantities of glycerol. A mitogen-activated protein kinase-encoding gene OSM1 was isolated from M. grisea and shown to encode a functional homolog of HIGH-OSMOLARITY GLYCEROL1 (HOG1), which encodes a mitogen-activated protein kinase that regulates cellular turgor in yeast. A null mutation of OSM1 was generated in M. grisea by targeted gene replacement, and the resulting mutants were sensitive to osmotic stress and showed morphological defects when grown under hyperosmotic conditions. M. grisea deltaosm1 mutants showed a dramatically reduced ability to accumulate arabitol in the mycelium. Surprisingly, glycerol accumulation and turgor generation in appressoria were unaltered by the Deltaosm1 null mutation, and the mutants were fully pathogenic. This result indicates that independent signal transduction pathways regulate cellular turgor during hyperosmotic stress and appressorium-mediated plant infection. Consistent with this, exposure of M. grisea appressoria to external hyperosmotic stress induced OSM1-dependent production of arabitol.

Inactivation of the mitogen-activated protein kinase Mps1 from the rice blast fungus prevents penetration of host cells but allows activation of plant defense responses

The rice blast fungus, Magnaporthe grisea, generates enormous turgor pressure within a specialized cell called the appressorium to breach the surface of host plant cells. Here, we show that a mitogen-activated protein kinase, Mps1, is essential for appressorium penetration. Mps1 is 85% similar to yeast Slt2 mitogen-activated protein kinase and can rescue the thermosensitive growth of slt2 null mutants. The mps1-1Delta mutants of M. grisea have some phenotypes in common with slt2 mutants of yeast, including sensitivity to cell-wall-digesting enzymes, but display additional phenotypes, including reduced sporulation and fertility. Interestingly, mps1-1Delta mutants are completely nonpathogenic because of the inability of appressoria to penetrate plant cell surfaces, suggesting that penetration requires remodeling of the appressorium wall through an Mps1-dependent signaling pathway. Although mps1-1Delta mutants are unable to cause disease, they are able to trigger early plant-cell defense responses, including the accumulation of autofluorescent compounds and the rearrangement of the actin cytoskeleton. We conclude that MPS1 is essential for pathogen penetration; however, penetration is not required for induction of some plant defense responses.

Effect of epidermal growth factor on cultured rat hepatocytes poisoned by CCl4

AIM

To study the effects of epidermal growth factor (EGF) on CCl4-induced primary cultured hepatocytes injury.

METHODS

Alanine amino-transferase (AlaAT) and aspartate aminotransferase (AspAT) activities and K+ concentractions were determined by the Auto-biochemistry Assay System. Malondialdehyde (MDA) was determined by thiobarbituric acid method. Radioactivity was determined by liquid scintillometry. Light microscopy and electron microscopy were used.

RESULTS

EGF 40 micrograms.L-1 decreased CCl4 (10 mmol.L-1)-induced damages of rat primary cultured hepatocytes by decreasing AlaAT and AspAT leakage and MDA production, and promoted RNA and DNA synthesis, with a high positive correlation between intracellular K+ leakage and DNA syntheses (r = 0.99, P < 0.01). Cytopathological study showed that EGF decreased damage of liver cells.

CONCLUSION

EGF maintains the stability of cellular lipid membrane and promotes syntheses of RNA and DNA of hepatocytes, and intracellular K+ transference is a promotor of the message transmission of DNA synthesis.

MAP kinase and cAMP signaling regulate infection structure formation and pathogenic growth in the rice blast fungus Magnaporthe grisea

Many fungal pathogens invade plants using specialized infection structures called appressoria that differentiate from the tips of fungal hyphae contacting the plant surface. We demonstrate a role for a MAP kinase that is essential for appressorium formation and infectious growth in Magnaporthe grisea, the fungal pathogen responsible for rice blast disease. The PMK1 gene of M. grisea is homologous to the Saccharomyces cerevisiae MAP kinases FUS3/KSS1, and a GST-Pmk1 fusion protein has kinase activity in vitro. pmk1 mutants of M. grisea fail to form appressoria and fail to grow invasively in rice plants. pmk1 mutants are still responsive to cAMP for early stages of appressorium formation, which suggests Pmk1 acts downstream of a cAMP signal for infection structure formation. PMK1 is nonessential for vegetative growth and sexual and asexual reproduction in culture. Surprisingly, when expressed behind the GAL1 promoter in yeast, PMK1 can rescue the mating defect in a fus3 kss1 double mutant. These results demonstrate that PMK1 is part of a highly conserved MAP kinase signal transduction pathway that acts cooperatively with a cAMP signaling pathway for fungal pathogenesis.

A genetic map of Gibberella fujikuroi mating population A (Fusarium moniliforme)

We constructed a recombination-based map of the fungal plant pathogen Gibberella fujikuroi mating population A (asexual stage Fusarium moniliforme). The map is based on the segregation of 142 restriction fragment length polymorphism (RFLP) markers, two auxotrophic genes (arg1, nic1), mating type (matA+/matA-), female sterility (ste1), spore-killer (Sk), and a gene governing the production of the mycotoxin fumonisin B1 (fum1) among 121 random ascospore progeny from a single cross. We identified 12 linkage groups corresponding to the 12 chromosome-sized DNAs previously observed in contour-clamped homogeneous electric field (CHEF) gels. Linkage groups and chromosomes were correlated via Southern blots between appropriate RFLP markers and the CHEF gels. Eleven of the 12 chromosomes are meiotically stable, but the 12th (and smallest) is subject to deletions in 3% (4/121) of the progeny. Positive chiasma interference occurred on five of the 12 chromosomes, and nine of the 12 chromosomes averaged more than one crossover per chromosome. The average kb/cM ratio in this cross is approximately 32.

[The study of interleukin-2 and interleukin-2 receptor in patients with pulmonary tuberculosis]

IL-2 level and IL-2R expression of peripheral blood lymphocytes (PBL) were measured in 25 patients with type III and advanced tuberculosis (TB). The results showed that IL-2 level in patients was lower than that in controls, and that in the patients whose history of TB was over 3 years was significantly lower than that in the patients whose history of TB was within 3 years; There was no significant difference between the IL-2R expression on unstimulated PBL from patients and controls. IL-2R expression in PHA-stimulated PBL after culturing 72 hours in patients was significantly lower than that in controls, and that in the patients over 3 years was significantly lower than that in the patients within 3 years. The data indicated that the function of T helper cells in patients with TB was impaired, and the impairment was more serious in the patients with longer illness.