MexXY-OprM efflux pump is required for antagonism of aminoglycosides by divalent cations in Pseudomonas aeruginosa

Antagonism of aminoglycosides by divalent cations is well documented for Pseudomonas aeruginosa and is regarded as one of the problems in aminoglycoside therapy. It is generally considered that divalent cations interfere with uptake of aminoglycosides at both the outer and inner membranes. It has been demonstrated recently that aminoglycosides can be removed from cells of P. aeruginosa by the three-component multidrug resistance efflux pump MexXY-OprM. We sought to investigate the interplay between efflux and uptake in resistance to aminoglycosides in P. aeruginosa. To do so, we studied the effects of the divalent cations Mg(2+) and Ca(2+) on susceptibility to aminoglycosides in a wild-type strain of P. aeruginosa and in mutants either overexpressing or lacking the MexXY-OprM efflux pump. MICs of gentamicin, streptomycin, amikacin, apramycin, netilmicin, and arbekacin were determined in Mueller-Hinton broth in the presence of cations added at concentrations that varied from 0.125 to 8 mM. We found, unexpectedly, that while both Mg(2+) and Ca(2+) antagonized aminoglycosides (up to a 64-fold decrease in susceptibility at 8 mM), antagonism was seen only in the strains of P. aeruginosa that contained the functional MexXY-OprM efflux pump. Our results indicate that inhibition of the MexXY-OprM efflux pump should abolish the antagonism of aminoglycosides by divalent cations, regardless of its precise mechanism. This may significantly increase the therapeutic index of aminoglycosides and improve the clinical utility of this important class of antibiotics.

[Study on the mode of inheritance for familial polycystic ovary syndrome]

OBJECTIVE

To investigate the mode of inheritance of polycystic ovary syndrome(PCOS).

METHODS

The first female relatives with irregular cycle and the first male relatives with premature balding in each nuclear family were designated the affected. Their prevalence rates in families were respectively calculated. Analyses of segregation ratio were carried out among 139 nuclear families with PCOS by the methods of simple segregation and complex segregation of genetic epidemiology, respectively.

RESULTS

The prevalence rates of irregular cycle among mothers and sisters with PCOS were 37.4% and 33.1% respectively, and the prevalence rates of premature balding among fathers and brothers of patients were 19.4% and 6.5%, respectively. The simple segregation analysis indicated that the segregation ratio of PCOS trait in siblings was 0.3023, the complex segregation analysis indicated that it fitted in with the inheritance model of co-dominant disorder with full penetrance and sporadic cases. The frequency of homozygote of disease gene in population was 0.046.

CONCLUSION

PCOS presents the mode of co-dominant inheritance with complete penetrance.

IL-1H, an interleukin 1-related protein that binds IL-18 receptor/IL-1Rrp

IL-18, or IGIF (interferon-gamma inducing factor), is an IL-1-related, pro-inflammatory cytokine, which plays a pivotal role in systemic and local inflammation. We have identified and characterized IL-1H, a novel IL-1-related molecule. IL-1H appears to be expressed in most tissues with relatively high levels in testis, thymus and uterus. The IL-1H transcripts were stimulated by phorbol ester (PMA) in human cell lines (A431, THP-1 and KG-1) and peripheral blood mononuclear cells (HPBMC) and dendritic cells (NHDC). The protein sequence of IL-1H is mostly related to IL-1ra with a similarity of 36%. A short form of IL-1H was identified, and lacks a 40-amino acid segment in the amino-terminal region of the protein. When expressed in mammalian cells, two secreted polypeptides of IL-1H were identified: an uncleaved and a cleaved form starting with amino acid Val-46. Furthermore, IL-1H binds the IL-18 receptor, but not the IL-1 receptor. These findings suggest that IL-1H may be another ligand for the IL-18 receptor and a new player in the inflammatory and immune responses mediated by the IL-18/IL-18R axis.

[Study on parents phenotypes in women with polycystic ovary syndrome]

OBJECTIVE

To explore the parents phenotypes in women with polycystic ovary syndrome (PCOS).

METHODS

Clinical data were collected by questionnaires from 139 parents of women with PCOS and from 137 parents of controls with normal menses. It was compared for the distribution of mother's menses irregularity, father's premature balding and parents hypertension by chi-square tests among parents of the PCOS group and of the controls. A multiple Logistic regression model was applied for more detailed analyses.

RESULTS

The prevalences of mother's menses irregularity, the incidence of father's premature balding and father's hypertension was significantly higher in PCOS group (38.1%, 19.4% and 30.9%, respectively) than in the controls (3.6%, 5.1% and 16.1%, respectively P < 0.01). The prevalence of mother's hypertension was higher in the PCOS group (23.0%) than in the controls (13.9%), but the difference was not significant (P = 0.06). When mother's menses irregularity, father's premature balding and father's hypertension were entered the Logistic regression model, all the odds ratio (OR) values were still much higher than 1 (P < 0.005). The partial regression coefficients of the three predictors changed little when they were entered the model in turn. The partial regression coefficients for father's age was very small when it entered the model as a possible confounding factor(P > 0.05). The differences between maximum -2log likelihoods used to evaluate the role responsible for the occurrence of PCOS in their daughters indicated that: mother's menses irregularity > father's premature balding > father's hypertension.

CONCLUSION

In addition to mother's menses irregularity and father's premature balding, father's hypertension may also be an independent phenotype in families of women with PCOS.

[Study on the relationship between a polymorphism of tumor necrosis factor-alpha gene and the pathogenesis of polycystic ovary syndrome]

OBJECTIVE

To investigate the relationship between -308 bp polymorphism in tumor necrosis factor-alpha (TNF-alpha) gene promoter region and the pathogenesis of polycystic ovary syndrome (PCOS).

METHODS

One hundred eighteen Chinese women with PCOS (44 were obese, and 74 nonobese) and 54 controls were genotyped according to the fragment length [87 bp and(or) 107 bp] of TNF-alpha gene promoter by the technique of polymerase chain reaction-restriction fragment length polymorphism. The distribution of TNF1 genotype (87/87) and TNF2 genotype (87/107 + 107/107) in the two groups and their relations to parameters of glucose metabolism associated with PCOS were compared.

RESULTS

There was no significant difference in the distribution of TNF1 and TNF2 genotypes between PCOS group and the controls (P > 0.05). In obese PCOS group, only significant lower insulin sensitivity index was found in TNF-1 genotype as compared with TNF2 genotype (P < 0.05). In nonobese PCOS group, there was no significant difference in all parameters of glucose metabolism between TNF1 and TNF2 genotype. All parameters of glucose metabolism in obese patients with TNF1 genotype were significantly different from those in nonobese with TNF1 genotype. However, significant differences were found only in some parameters when comparison was made between obese and nonobese within the TNF2 genotype group.

CONCLUSION

There is no association between TNF-alpha gene -308 bp polymorphism and the pathogenesis of polycystic ovary syndrome, but PCOS patients with TNF2 genotype may associate with improvement to certain degree on abnormal glucose tolerance usually existed in obese PCOS women.

Characterization of novel UCP5/BMCP1 isoforms and differential regulation of UCP4 and UCP5 expression through dietary or temperature manipulation

Mitochondrial uncoupling proteins have been implicated in the maintenance of metabolic rate and adaptational thermoregulation. We recently reported the identification of a brain-specific mitochondrial uncoupling protein homologue, UCP4. Here we characterized another newly described member of the uncoupling protein family, termed UCP5 (also called BMCP1). UCP5 transcripts are present in multiple human and mouse tissues, with an especially high abundance in the brain and testis. Expression of UCP5 in mammalian cells reduces the mitochondrial membrane potential. Multiple isoforms of UCP5 were identified and exhibited tissue-specific distribution and different potency in reduction of membrane potential. Furthermore, the mRNA abundance of both UCP4 and UCP5 is modulated by nutritional status or temperature in a tissue-specific manner in mice. Brain UCP4 and UCP5 mRNA transcripts rose by 1.5- and 1.7-fold, respectively, and liver UCP5 expression increased by 1.8-fold in response to acute cold exposure. A high-fat diet increased UCP5 mRNA in liver by 1.6-fold selectively in the obesity-resistant A/J but not in the obesity-prone C57BL/6J mouse strain. Liver UCP5 expression decreased significantly with a 24 h fast and was restored to the normal level after refeeding. In contrast, brain transcripts for both genes were not significantly altered by fasting or high-fat diet. These findings are consistent with the notion that UCP4 and UCP5 may be involved in tissue-specific thermoregulation and metabolic changes associated with nutritional status.

Interplay between efflux pumps may provide either additive or multiplicative effects on drug resistance

The effects of simultaneous expression of several efflux pumps on antibiotic resistance were investigated in Escherichia coli and Pseudomonas aeruginosa. Several combinations of efflux pumps have been studied: (i) simultaneous expression of a single-component efflux pump, which exports antibiotics into the periplasm, in combination with a multicomponent efflux pump that accomplishes efflux directly into the external medium; (ii) simultaneous expression of two single-component pumps; and (iii) simultaneous expression of two multicomponent pumps. It was found that when efflux pumps of different structural types were combined in the same cell (the first case), the observed antibiotic resistance was much higher than that conferred by each of the pumps expressed singly. Simultaneous expression of pairs of single-component or multicomponent efflux pumps (the second and third cases) did not produce strong increases in antibiotic resistance.

[Contrast study on effect of shenkang injection and benazepril on human glomerular mesangial extracellular matrix]

OBJECTIVE

To explore the intensity of inhibition of Shenkang Injection (SKI) and Benazepril on various ingredients of human glomerular mesangial extracellular matrix (ECM).

METHODS

Effect of SKI, a herbal preparation for lowering adverse Qi, despelling turbidness, supplementing Qi and activating circulation, and Benazepril were observed by cultured glomerular mesangial cell technique in vitro.

RESULTS

SKI could inhibit the fibronetin, laminin, and type IV collagen of ECM, and the action was dose-dependent. Benazepril could also inhibit the fibronetin and type IV collagen of ECM but was weaker in intensity.

CONCLUSION

The effect of SKI was superior to Benazepril in inhibiting ECM.

[The calculation of Einstein spontaneous emission coefficients of HBr molecule]

The Einstein spontaneous emission coefficients of some rovibrational transitions of HBr molecule have been calculated from the first principle. The calculation is carried out for the deltav = 1 transitions of v < or = 7, J < or = 14 of R and P branches. A time-resolved Fourier transform infrared emission spectrum of the HBr molecule was recorded. The observed intensities of the spectral lines well agree the calculated coefficients.

The insulin-like growth factor 1 receptor induces transformation and tumorigenicity of ovarian mesothelial cells and down-regulates their Fas-receptor expression

Cell proliferation and papillogenesis are growth factor-sensitive events in the ovarian mesothelium, the tissue source of ovarian epithelial cancer. To further investigate the regulation of cell proliferation in this tissue, rabbit ovarian mesothelial cells (OMC) were transfected in vitro with a CVN expression vector carrying the human gene for insulin-like growth factor 1 receptor (IGF-1R). The growth characteristics of IGF-1R transfectants (OMIR) and their response to IGF-1 were then compared with those of OMC in serumless HL-1 cultures. OMIR cells formed epithelial-like colonies and, even when nonconfluent, produced tridimensional structures reminiscent of papillae seen in ovarian serous epithelial tumors. After 3 and 7 days of exposure to IGF-1, OMIR cells grew approximately 20-fold (P < 0.05), and papillogenesis was 15- to 25-fold over similar events in OMC, respectively. Exposure to treatment with antisense oligonucleotides against IGF-1R mRNA inhibited OMIR growth rate by 70%. Western immunoblotting and flow cytometry revealed higher expression of IGF-1R in OMIR cells than in OMC. The reverse was true when Fas-receptor expression was evaluated. OMIR cells were clonogenic in 15% serum-rich soft agar assay (OMIR:OMC colony-forming ratio 150-200:1), and tumorigenic in nude mice in which high-grade carcinomas with occasional lung metastases were observed. These data suggest that IGF-1R plays a role in ovarian epithelial carcinogenesis. The overexpression of this receptor induces transformation and morphogenesis of OMCs via an autocrine mechanism. IGF-1R may down-regulate the Fas expression rendering transformed ovarian mesothelial cells resistant to apoptosis.

Activating SRC mutation in a subset of advanced human colon cancers

The discovery of Rous sarcoma virus (RSV) led to the identification of cellular Src (c-Src), a non-receptor tyrosine kinase, which has since been implicated in the development of numerous human cancers. c-Src has been found to be highly activated in colon cancers, particularly in those metastatic to the liver. Studies of the mechanism of c-Src regulation have suggested that c-Src kinase activity is downregulated by phosphorylation of a critical carboxy-terminal tyrosine (Tyr 530 in human c-Src, equivalent to Tyr 527 in chicken Src) and have implied the existence of activating mutations in this C-terminal regulatory region. We report here the identification of a truncating mutation in SRC at codon 531 in 12% of cases of advanced human colon cancer tested and demonstrate that the mutation is activating, transforming, tumorigenic and promotes metastasis. These results provide, for the first time, genetic evidence that activating SRC mutations may have a role in the malignant progression of human colon cancer.

UCP4, a novel brain-specific mitochondrial protein that reduces membrane potential in mammalian cells

Uncoupling proteins (UCPs) are a family of mitochondrial transporter proteins that have been implicated in thermoregulatory heat production and maintenance of the basal metabolic rate. We have identified and partially characterized a novel member of the human uncoupling protein family, termed uncoupling protein-4 (UCP4). Protein sequence analyses showed that UCP4 is most related to UCP3 and possesses features characteristic of mitochondrial transporter proteins. Unlike other known UCPs, UCP4 transcripts are exclusively expressed in both fetal and adult brain tissues. UCP4 maps to human chromosome 6p11.2-q12. Consistent with its potential role as an uncoupling protein, UCP4 is localized to the mitochondria and its ectopic expression in mammalian cells reduces mitochondrial membrane potential. These findings suggest that UCP4 may be involved in thermoregulatory heat production and metabolism in the brain.

Analysis of colorectal cancer by comparative genomic hybridization: evidence for induction of the metastatic phenotype by loss of tumor suppressor genes

Current models suggest that colon cancer initiation and progression are secondary to both the activation of oncogenes and the deletion of tumor suppressor genes. The role of each, however, is still poorly understood, particularly with regard to the induction of metastasis. We hypothesized that genetic differences exist between tumors that metastasize distantly and those that do not, and that oncogenes and tumor suppressor genes participate equally in this process. To address this hypothesis, human tumor specimens from localized [tumor-node-metastasis (TNM) stage I-III] and primary colon cancers (n = 10) were directly compared with metastatic (TNM stage IV) lesions (n = 10) using comparative genomic hybridization analysis. Although several alterations were shared equally between primary tumors and metastases (+7q, +19q, and +20q), two patterns of distinguishing alterations were observed: (a) alterations that were more extensive in liver metastases than in primary tumors (+8q, +13q, -4p, -8p, -15q, -17p, -18q, -21q, and -22q); and (b) alterations that were unique to metastatic lesions (-9q, -11q, and -17q). Overall, genetic losses were more common than gains, and, more importantly, the number of losses/tumor was significantly higher for metastases than for primary tumors (9.3 + 1.3 versus 4.1 + 0.7; P = 0.00062, Wilcoxon's rank-sum test). The distinct predominance of genetic losses in the metastatic lesions when compared with the primary localized tumors provides evidence that the metastatic phenotype is induced by the deletion of tumor suppressor genes and permits the construction of physical maps targeting regions where novel tumor suppressor genes are likely to exist.

Elevated c-Src protein expression is an early event in colonic neoplasia

The molecular events regulating the development and progression of colonic neoplasia are currently being delineated. Recent studies have implicated c-Src protein kinase activation as an early event in the malignant transformation of colonic epithelial cells. However, increased c-Src activity has also been reported in colon carcinomas as well as in metastatic hepatic and extrahepatic colon carcinomas. To further investigate the potential role of c-Src in the progression of colonic neoplasia, we analyzed c-Src levels by immunohistochemistry in 27 colorectal resection specimens. Mouse monoclonal antibody to c-Src protein was applied to 3-micron sections from formalin-fixed, paraffin-embedded tissues using the avidin-biotin-peroxidase method. The combination of adenomatous (AD) and adjacent carcinomatous mucosa (CA) specimens were present in 20 of 27 patients. In 15 cases, synchronous metastatic (MT) lesions were available for evaluation. Strong c-Src expression was evident in 95% of AD (n = 20), in contradistinction to 32% of MT (n = 19) and 14% of CA (n = 22). Weak-to-moderate c-Src expression was seen in adjacent normal colonic mucosa (NM) in 96% of cases. Signed rank test univariate analysis revealed a statistically significant difference in c-Src expression between NM/AD (p = 0.0001), NM/CA (p = 0.0001), NM/MT (p = 0.0006), AD/CA (p = 0.0001), and AD/MT (p = 0.0002). No significant correlation between levels of c-Src expression and patient survival, tumor size, histologic grade, or tumor configuration was observed using the Cox's Regression Model. Similar results were obtained by analysis of c-Src protein levels and c-Src kinase activity as measured by Western blot and in vitro kinase assays of representative cases. Our results indicate that: (a) elevated c-Src expression is an important early event during colorectal carcinogenesis; (b) its activation may be involved in tumor progression in a subset of colonic carcinomas; and (c) additional molecular events are necessary for invasion to occur.

Seed Treatment Using Pre-infiltration and Biocontrol Agents to Reduce Damping-off of Corn Caused by Species of Pythium and Fusarium

Bioassays were conducted in a greenhouse at 18°C to determine the effectiveness of a seed treatment used in combination with biocontrol agents for the reduction of corn damping-off caused by species of Pythium and Fusarium. Corn seeds were infiltrated with tap water, drained, air-dried, and then coated with biomass of an antagonistic fungus, Gliocladium virens isolate Gl-3, or an antagonistic bacterium, Burkholderia cepacia isolates Bc-B or Bc-1, or a combination of Gl-3 with each of the bacterial isolates. A nonsterile field soil was infested with a combination of pathogens: Pythium ultimum, P. arrhenomanes, and Fusarium graminearum at 2 inoculum rates (1× and 4×). Pre-infiltration enhanced (P ≤ 0.05) disease control with most treatments at both inoculum rates. Treatments with biocontrol agents alone or in combination, as well as the fungicide captan, effectively reduced the disease at a pathogen inoculum rate of 1×, resulting in greater (P ≤ 0.05) seedling stands, plant height, and fresh weight, and lower (P ≤ 0.05) root rot severity compared with untreated seeds in infested soil. At a pathogen inoculum rate of 4×, stands were lower (P ≤ 0.01) and root-rot severity was higher (P ≤ 0.01) compared to those at 1× for all treatments. Nevertheless, coating seeds with all biocontrol agents (alone or in combination), except with Bc-1 alone, reduced disease (P ≤ 0.05) compared to untreated seeds in infested soil. At both inoculum rates of 1× and 4×, coating seeds with Gl-3 + Bc-B was more effective (P ≤ 0.05) in disease control than any other treatment, resulting in stands, growth rate (plant height and fresh weight), and root rot severity similar to plants from untreated seeds in noninfested soil. In addition, when the exudate from a 2-h infiltration of corn seed was added to the seeds during seed coating, seedling stand was often lower and root rot severity was often higher than those from infiltrated seeds (P ≤ 0.05). These results indicated that the infiltration process removed certain exudates, including nutrients and/or stimulants (not detected in this study) that might be utilized by pathogens to initiate seed infection. A thin-layer chromatography (TLC) profile of the exudates showed the presence of eight amino acids and three major carbohydrates.

Association of Phoma terrestris, Pythium irregulare, and Fusarium acuminatum in Causing Red Root Rot of Corn

Greenhouse and field tests were conducted in 1992 and 1993 to determine the causal pathogen(s) of red root rot (RRR) of corn. Corn hybrids Dekalb DK 522, DK 572, DK 677, and DK 582 were utilized. Phoma terrestris, Pythium irregulare, and Fusarium acuminatum were used alone or in combination to infest potting mix in greenhouse tests or soil in field tests. Results indicated that P. terrestris is the primary pathogen in the RRR complex of corn in Delaware. When P. terrestris and Pythium irregulare were associated, the disease progressed faster and was more severe, resulting in significantly higher (P ≤ 0.01) root rot, basal stalk rot, and wilt. F. acuminatum played a minor role in causing the disease, with little additional symptom development when combined with P. terrestris or Pythium irregulare.

[A study of genetic patterns of idiopathic epilepsy]

OBJECTIVE

To explore genetic patterns of idiopathic epilepsy (IEP).

METHODS

Using familial analysis, tests for multifactorial inheritance and segregation analysis, we studied 210 pedigrees with IEP found in a population survey in Shangdong province.

RESULTS

The genetic pattern of IEP is not polygenic but is mainly influenced by autosomal recessive disorders. The results of segregation analysis indicate that the genetic pattern of U*U multiplex families and U*A group is autosomal recessive. Only a few cases in U*U group may accept the assumption of autosomal recessive inheritance while the other are sporadic cases. The frequency of sporadic cases is approximately 78.5%. Genetic heterogeneity may influence U*U(f) group and U*U group.

CONCLUSION

Further and careful empirical scrutiny of U*U(f) group and the sporadic cases in U*U group offers the best hope for getting a clear understanding of genetic patterns and mechanisms in IEP.

Genetic analysis of the stationary phase-induced mcb operon promoter in Escherichia coli

A combination of deletion analysis and random mutagenesis was used to identify regulatory elements in Pmcb, the stationary phase-induced promoter of the mcb operon. Our results indicate that Pmcb is controlled by at least three different factors, two previously identified and at least one unknown factor, which act at four different sites in the promoter. Sequences between -344 and -164 upstream of the transcriptional start site were required for wild-type levels of mcb transcription in stationary phase. More dramatic reductions in both exponential and stationary phase expression were observed when sequences from -164 to -54 were deleted. Point mutations located between -105 and -138 decreased both exponential and stationary phase expression. All but one of these mutations decreased OmpR-dependent activation of Pmcb transcription. EmrR, also known as MprA, acts directly or indirectly at sequences downstream of -54 to repress Pmcb. A minimal promoter containing sequences from -34 to +79 was still induced > or = 10-fold in stationary phase. Point mutations within this region identified sequences at -8, -11, -30, -31 and -32 as important for Pmcb activity. These bases are in the gearbox sequence, present in Pmcb and several other stationary phase-induced Escherichia coli promoters.

Activation of c-Src by receptor tyrosine kinases in human colon cancer cells with high metastatic potential

Recent data suggest that signal transduction may have a critical role in the development and regulation of the metastatic phenotype. Here, we investigated the role of c-Src activation in the process of human colon cancer metastasis to the liver. Our data, derived from two different sets of human colon cancer cell line metastatic variants, suggest that not only do highly-metastatic cells display constitutively elevated c-Src protein kinase activity when compared to poorly metastatic cells, but also that receptor tyrosine kinases participate in the ligand-activation of c-Src above basal levels. Specifically, the epidermal growth factor receptor (EGFR), p185HER2/Neu and the hepatocyte growth factor receptor (c-Met) appear to be linked to the process because they preferentially activate c-Src in highly-metastatic cells. EGFR was found to associate with c-Src in colon cancer cells and specific inhibitors of the EGFR resulted in a reduction of c-Src activity to basal levels. In addition, c-Src transfectants displayed partially-activated EGFRs, suggesting a feedback role for c-Src in the regulation of the EGFR. p185HER2/Neu was also identified in immunocomplexes of c-Src following ligand activation of the EGFR, but only in highly-metastatic cells. Collectively, these observations suggest a paradigm whereby c-Src interacts with multiple cell-surface growth factors in a catalytic fashion for the development of tumor cells with metastatic potential.

Overexpression of normal c-Src in poorly metastatic human colon cancer cells enhances primary tumor growth but not metastatic potential

Whereas genetic paradigms are now defined for the development of human colon cancer, little is known regarding the mechanisms that regulate development of the metastatic phenotype. Recent reports have indirectly linked the expression and activation of c-Src to the process of human colon cancer metastasis. Whereas v-Src, a highly activated mutational derivative of c-Src, has been shown to induce metastasis, normal c-Src has not been tested for this property. We hypothesized that c-Src overexpression in the milieu of a poorly metastatic cancer cell might permit the development of a highly metastatic cell. Two poorly metastatic human colon cancer cell lines were stably transfected with expression vectors encoding normal human c-Src. Clones producing 4-10-fold more c-Src than controls were injected s.c. and intrasplenically into the nude mouse to assess primary tumor growth and liver metastatic potential. Whereas metastatic potential was unaffected, primary tumor growth in vivo was significantly enhanced by c-Src overexpression. No effects on rates of tumor cell proliferation were seen in vitro. Our findings suggest that normal c-Src may be necessary but is insufficient for the induction of the metastatic phenotype.

Biliary glycoprotein is overexpressed in human colon cancer cells with high metastatic potential

Carcinoembryonic antigen (CEA) has been recently implicated in the process of human colon cancer liver metastasis by means of an adhesion mechanism. Based on the strong sequence and structural homology of biliary glycoprotein (BGP) to CEA, we hypothesized that BGP might be overexpressed at the RNA and protein level in tumor cells with high metastatic potential. We have found the BGP messenger RNA derived from highly metastatic colon cancer cells is constitutively overexpressed-nearly fourfold greater than poorly metastatic cells-and that BGP expression is induced by interferon-gamma. Similarly, we have demonstrated that BGP protein levels were constitutively elevated in highly metastatic human colon cancer cells when compared to poorly metastatic cells. Collectively these results suggest that the basal and interferon-stimulated expression of BGP transcripts may be regulated in a manner similar to CEA and that a potential role in the process of metastasis may be inferred.

Seed Treatment with a Fungal or a Bacterial Antagonist for Reducing Corn Damping-off Caused by Species of Pythium and Fusarium

Bioassays were conducted under greenhouse conditions to test the efficacy of antagonists applied to corn (Zea mays) seed for protection against seed rot and seedling damping-off at 18 and 25°C in a field soil artificially infested with a combination of Pythium ultimum, P. arrhenomanes, and Fusarium graminearum. Biomass of Gliocladium virens isolates Gl-3 or Gl-21, Trichoderma viride isolate Tv-1, or peat-based slurry of Burkholderia cepacia isolates Bc-B, Bc-T, or Bc-1 was coated individually onto corn seeds in one test, and Gl-3 or Bc-B at four inoculum levels was used in another test. Seed treatments with most of the biocontrol agents, as well as with the fungicide captan, significantly (P ≤ 0.05) increased seedling stand, plant height and fresh weight, and decreased root rot severity compared with untreated seeds in pathogen-infested soil. Coating seeds with the biocontrol fungus G. virens isolate Gl-3 was the most effective treatment, resulting in greater (P ≤ 0.05) seedling stand, plant height, and fresh weight, and lower (P ≤ 0.05) severity of root rot than those parameters from seeds treated with captan or other antagonists at both temperatures. The results from the seeds treated with Gl-3 were similar to those of untreated seeds in noninfested soil. In treatments with Bc-1, Bc-T, Bc-B, or Tv-1, incubation temperature affected plant emergence, root rot severity, plant height, and fresh weight (P ≤ 0.01). Conversely, in seeds coated with Gl-3 or Gl-21, these parameters were similar at both temperatures. The minimum number of propagules needed per corn seed to obtain plant emergence comparable to that from captan-treated seeds was between 10⁴ and 10⁵ CFU for Gl-3 and >10⁸ for Bc-B. When propagules of Gl-3 were applied at a rate >10⁶ CFU per seed, seedling emergence was greater (P ≤ 0.05) than that from captan-treated seeds.

Effect of lignocaine in myocardial contusion: an experiment on rabbit isolated heart

1. The reported incidence of myocardial contusion after blunt chest trauma varies from 16 to 76%. Of these patients, about 6% present a severe, life threatening contusion. We used an isolated heart preparation to examine the effect of lignocaine on myocardial performance after contusion. 2. Thirty hearts obtained from male New Zealand rabbits were perfused at constant flow according to the Langendorff technique and were divided into four groups. The following parameters were measured at frequent intervals for 60 min: mean coronary perfusion pressure (CPP), left ventricular diastolic pressure (LVDP), developed pressure (DP), dP/dtmax, dP/dtmin. 3. Group 1 (n = 6) served as control, group 2 (n = 7) received lignocaine for 20 min (15 microM for the first 10 min and 30 microM for the following 10 min), group 3 (n = 9) had a contusion leading to a 30-50% decrease in dP/dtmax and group 4 (n = 8) had the contusion and the lignocaine infusion was started 10 min after the contusion and stopped after 30 min. Lignocaine concentration was measured in the effluent. 4. Lignocaine alone moderately decreased contractility in group 2. In group 3, after contusion, DP, dP/ dtmax, and dP/dtmin were markedly decreased during the 60 min recording period. In group 4, lignocaine infusion rapidly restored contractility. DP, dP/dtmax and dP/dtmin returned towards their basal values. This improvement of contractility remained stable, even after lignocaine infusion was discontinued. 5. In our rabbit isolated heart preparation, lignocaine at a low therapeutic concentration was able to restore contractility after contusion. These results need to be confirmed by other studies but this may lead to promising therapeutic intervention.

Identification of genetic alterations associated with the process of human experimental colon cancer liver metastasis in the nude mouse

Understanding the genetic elements controlling the process of tumor metastasis to distant organ sites such as the liver may be the key to improving survivorship from colon cancer. By using standard cytogenetic techniques in combination with comparative genomic hybridization, multiple genetic imbalances within three human colon cancer cell lines previously selected for differences in liver-metastatic behavior were identified. The entire genome of one poorly metastatic cell line (KM12C) was compared directly with that of two highly metastatic cell lines (KM12SM, KM12L4A) derived from it. A number of chromosomal gains (8q, 12q15, 20q11.2) and losses (5p13, 6p21.3, 18) were common to all three cell lines and are likely related to early tumor development rather than to the selection process used to generate cell lines of increased metastatic potential. Chromosomal imbalances detected only in the highly metastatic cell lines were also observed. KM12SM showed losses of portions of 2p22, 2q24.3--> 2q32.2, 4p15.3--> cen, 4q24 without the 13q and 15q22.3 gains noted for KM12C. Both gains (1p31.3--> 1p21, 2q22--> 2q33, 3cen--> 3q26.2, 5q14--> 5q23, 6cen--> 6q23) and losses (16p, 17p, 17q 19p, 19q 22q) were observed for KM12L4A but not for the other two cell lines. Identification of these alterations provides valuable insight into the process of experimental liver metastasis and is a first step towards mapping genes linked to the terminal phases of human colon cancer progression.

Identification of a differentially-expressed message associated with colon cancer liver metastasis using an improved method of differential display

Images

[Comparison of simple methods to screen predisposing eye of primary angle-closure glaucoma]

6,584 population over 40 years old in Canton universities and factories were screened for the predisposing eyes of primary angle-closure glaucoma (PACG). In the screening, three methods for the measurement of anterior chamber depth were used and compared and the critical limits of two simple ones of them [peripheral anterior chamber depth (PACD) and oblique illumination test with a flashlight] were evaluated. It was found that the incidence of PACG is as high as 10.0% in eyes with axial anterior chamber depth (AACD) < or = 2.0 mm, it is 6.7% in eyes with peripheral anterior chamber depth (PACD) < or = 1/4 corneal thickness (CT) and is 6.9% in eyes with iris light band ratio (ILBR) < or = 1/4. Also, we found that the incidence of PACG is as high as 77.8% in eyes with AACD < or = 1.6 mm and 100.0% in, AACD < or = 1.4 mm. The authors propose that PACD < or = 1/4 CT and ILBR < or = 1/4 can be the critical values of the two methods for the primary step of PACG screening.

Desmopressin (DDAVP) acts on platelets to generate platelet microparticles and enhanced procoagulant activity

Desmopressin (DDAVP), an analog of vasopressin (AVP), has wide clinical application as an anti-hemorrhagic (AH) agent. DDAVP in vivo releases vWF from endothelial cells but is reported to have little action on platelets. However, DDAVP is often used to improve hemostasis in platelet dysfunctions. We examined the effect of DDAVP on platelet microparticle (PMP) formation and procoagulant activity in vitro using platelets from normal volunteers and in vivo in six patients receiving DDAVP therapy. In the former, platelets were incubated with DDAVP (0.5 to 25 nM) and PMP released were stained with FITC-labeled MAb alpha-GP IIb/IIIa for flow cytometry. Procoagulant activity was measured in a clot-based assay using Russel's viper venom (RVV) calibrated with cephalin. A mean increase of 2-3 fold was observed in both PMP and procoagulant activity. Parallel to these observations was a dose-dependent rise in organelle-associated Ca2+. The assays were also performed on six patients prior to and at one hour after infusion of DDAVP, and similar but lesser effects were observed. We conclude that DDAVP acts on platelets in vitro, and that these effects may contribute to the hemostatic action of DDAVP in platelet dysfunctions in vivo.

Augmentation of carcinoembryonic antigen release from intact, viable tumor cells by a factor in human serum

BACKGROUND

Measurement of carcinoembryonic antigen (CEA) levels in human serum is frequently used to detect tumor recurrence in patients with resected primary colorectal cancers. These levels are highly variable from patient to patient, and the mechanism that determines these levels is still poorly understood.

METHODS

Using a 6-h in vitro CEA-release assay, we determined that a factor in human and fetal bovine sera significantly augments the release of CEA from the tumor cell surface into cell culture supernatants.

RESULTS

As little as 1% serum admixed with tumor cells results in CEA release up to 200% greater than that of serum-free controls. It is not inhibited by 1,10-phenanthroline or heat inactivation (of serum) but is calcium dependent. The electrophoretic mobility and membrane linkage of CEA released by serum appear to be identical to those of CEA released by bacterial phospholipase C. Because bacterial phospholipase C is known specifically to cleave the phosphoinositol (PI) glycan moiety that anchors CEA to the tumor cell surface, a mechanism of action for serum cleaving this anchor is suggested.

CONCLUSIONS

The large range of CEA levels observed in patients with colorectal cancers may be related to differential sensitivity of the CEA membrane anchor to the CEA-releasing factor in serum.

[Establishment and application of paper strip analysis for products processed with honey]

This method was applied for the qualitative and quantitative analysis of 12 kinds of products processed with honey. The method is simple, convenient, objective in qualification and accurate in qualification, thus suitable for quality control of product processed with honey.

Phospholipase C-gamma 1 is present on the surface of human colorectal cancer cells

Using murine monoclonal antibodies, we have detected the novel signal transducing enzyme, phospholipase C-gamma 1, on the surface of cultured human colorectal cancer cells. We have also demonstrated the presence of this enzyme on the surface of fresh human tumor cells derived from primary and metastatic colorectal tumors. This enzyme has previously been described to be associated only with the inner face of the plasma membrane and the cell cytosol. The finding of an enzyme critical to the signal transduction pathway may have important implications for additional functions of this protein.

[Amino acid analysis of retinal S-antigen and interphotoreceptor retinoid-binding protein]

Retinal S-antigen and interphotoreceptor retinoid-binding protein (IRBP) were purified by DEAE-Sephacel ionexchange chromatography and Con A Sepharose affinity chromatography. Amino acid analysis of the S-antigen and IRBP was carried out and compared with that presented by others. The possible reason for difference with regard to some amino acids and related problems were analyzed and discussed.

[The 43KD polypeptide in the proteins of human lens]

The total proteins, water--soluble proteins and the urea--soluble proteins of the lens from fetal, adult and senile cataract were determined by SDS--PAGE. It was found that there was a 43KD polypeptide in the capsular--epithelium of all lens stated above. The band on SDS-PAGE corresponding to 43KD polypeptide was wide in the water--soluble proteins of the cortex and nucleus of the lenses obtained from over 14-year-old individuals. It became blurred in the urea--soluble proteins of cortex and nucleus of lens with aging, whereas it became almost disappeared in the senile cataract lens.

[Effect of superoxide dismutase on experimental allergic uveitis]

In this study, experimental allergic uveitis (EAU) in guinea pigs was induced by an injection of bovine serum albumin (BSA) into the vitreous after having pre-immunized them intradermally with BSA plus incomplete Freund adjuvant, and the effect of superoxide dismutase (SOD) on EAU was observed. The result showed that, histopathologically, the phlogistic cell infiltration and exudation within the anterior ocular part of the SOD- treated animals reduced notably. It is suggested that SOD which can scavenge the free radical superoxide anion may alleviate the cellular reaction in the pathological process of uveitis.

The study of G6PD in erythrocyte and lens in senile and presenile cataract

The G6PD activity of erythrocytes in 113 male patients with senile and presenile cataract and 86 controls, and G6PD activity of lens in 30 patients with senile cataract and 42 controls were reported. The cataractous group had higher frequency of G6PD deficiency and lower average G6PD level in erythrocytes and lenses, but without statistical significance. The frequency of G6PD deficiency of erythrocytes in presenile cataractous group was higher than that of senile cataractous group but with no statistical significance too. However, the average G6PD level of erythrocytes in presenile cataractous group was lower than that of senile cataractous group and with statistical significance (P < 0.05). The G6PD activity of lenses only presenile in the cortex and have a positive correlation with that of erythrocytes. There was a case with deficiency of G6PD both of erythrocytes and cataractous lenses in both eyes. The results indicate that the deficiency of G6PD might be one of the cataractous pathogenetic factor for presenile cataract. Measurement of G6PD activity of erythrocytes among population might be of significance in finding the risk factor for cataract.

Detection of gene alteration for color vision defects by polymerase chain reaction

According to the fact that the abnormalities of visual pigment genes were always involved in the changing of the exon 5, two oligonucleotide primers were designed to amplify the exon 5 of red pigment gene and green pigment gene. After electrophoresis of the PCR products digested with Rsal or Sau3A, the DNA fragments from the exon 5 of red pigment gene (RPG) and green pigment gene (GPG) were separated since there are different restriction endonuclease sites. On the other hand, we analyzed the exon 5 related fragment by Southern blot hybridization with probe out of the 3' end of the fourth intron of green pigment gene. The results of PCR are consistent with nucleic acid hybridization. PCR technique will be of value in prenatal evaluation and genetic counselling.

Purification of bovine interphotoreceptor retinoid-binding protein and its uveitogenicity in Lewis rats

Interphotoreceptor retinoid-binding protein, IRBP, not only functioning as a shuttle to carry the retinoid between photoreceptor cells and pigment epithelium, but also inducing experimental autoimmune uveoretinitis (EAU), was purified by ConA Sepharose affinity chromatography from the fractions containing IRBP obtained in the course of ion-exchange chromatography by which the bovine retinal S-antigen was purified. This much simplified method allows more rapid purification of the two kinds of protein. EAU was successfully induced with injecting 50 micrograms of IRBP emulsified with Freund's complete adjuvant into the right hind footpads of Lewis rats. It was characterized by panophthalmia or endophthalmia with the severest damage in the posterior retina. Lymphocytes, mononuclear and polymorphonuclear cells were found to be the inflammatory cells of infiltration, with lymphocytes being predominant.

[Atmosphere pollution by sulfur dioxide during processing of zirantong]

This paper reports the colorimetric determination of total SO2 in Zirantong by the method of rosaniline hydrochlorid. Samper of processed Zirantong from the pharmacy have been analyzed and the quality specifications established. Optimum conditions for processing have been chosen and a procedure has been proposed for the recovery of the poisonous matter SO2 which is then transformed into a beneficial material.

[A clinical study and analysis of congenital lenticular dislocation (35 cases)]

Thirty-five cases of congenital lenticular dislocation seen in our Center since 1985 have been studied and analyzed clinically. By the survey of pedigrees and examination of these patients, including ocular, systemic, skeletal X-ray, psychocardiogram, and urinary sodium-nitroprusside test, 21 cases were diagnosed as Marfan's syndrome, 6 cases as simple ectopia lentis, 3 cases as Weill-Marchesani's syndrome, 4 cases as aniridia and 1 case as homecys tinuria. We found that the most significant ocular manifestation of congenital lenticular dislocation was reduction in visual acuity. The severity of visual disturbance varied with the types of dislocation and the visual deficiency was closely related to the intermediate-grade (II) dislocation of the lens. Examination of ERG showed normal function in most of the patients. From this, we believe that the major cause of visual reduction in congenital lenticular dislocation is lenticular myopia and astigmatism. There fore, early diagnosis and effective correction of vision should be emphasized to prevent the occurrence of amblyopia.

Nd:YAG laser treatment of congenital persistent pupillary membrane

Five case of severe congenital persistent pupillary membrane were successfully treated with Nd:YAG laser. The patient's age ranged from 6 to 33 years. After operation, they not only improved their visual acuities, but also got a function of round pupil as well as cosmetic effect. The author describes his experience about the choice of laser energy and technical methods used in Nd:YAG laser treatment of persistent pupillary membrane, and discusses the intra- and post-operative complications, too. Finally, the author emphasizes that provided the operator is skillful, and the choice of laser energy used is appropriate, no severe complications will occur. The author believes that treatment of severe congenital persistent pupillary membrane with Nd:YAG laser is a safe more effective method with less complications as compared with the traditional surgical procedures, and recommends to popularize it.

[Determination of hydrocortisone and methylprednisolone in plasma by reversed-phase HPLC]

A sensitive and rapid method for the simultaneous measurement of both hydrocortisone (HC) and methylprednisolone (MP) using dexamethasone (DX) as the internal standard was presented. High-performance liquid chromatograph Model 344 (Beckman, USA) with a 254 nm wavelength UV detector and reversed-phase Ultrasphere ODS (5 microns) column was used. Sample was extracted with ethyl acetate and the organic layer was evaporated to dryness under an air stream in a 37 degrees C water bath. The residue was dissolved in 30 microliters mobile phase and 20 microliters injected. The mobile phase of methanol and 0.01 mol/L acetate buffer (pH 3.0) (64:36) was pumped at 1.0 ml/min through the column. The detector was operated at 0.005 aufs. The retention time for HC, MP and DX was 5.43 min, 7.7 min and 11.5 min, respectively. Standard curve was linear in the concentration range of 0.02 to 1.28 mg/L for HC and 0.05 to 12.8 mg/L for MP. Sensitivity was 1 ng for HC and 1.5 ng for MP; extraction recovery 76-83%; within day CV less than 4%, and inter-day CV less than 6% for both steroids.

[Longitudinal changes of serum specific antibodies in Lewis rats immunized with IRBP]

The serum antibodies specific to either interphotoreceptor retinoid-binding protein (IRBP) or retinal S-antigen were longitudinally determined in Lewis rats immunized with 50 x 10(-6)g of IRBP emulsified with complete Freund's adjuvant. To our knowledge, it is the first time to purify IRBP and to address the experiment with IRBP in China. It was shown that the antibody specific to IRBP appeared on the 7th day, followed by a gradual increase, and reached its peak on the 26th day after immunization. No antibody specific to S-antigen was found. The relation between anti-IRBP antibody and experimental autoimmune uveoretinitis (EAU) which occurred in the increasing phase of the antibody suggests that the humoral immunity may be implicated in the pathogenesis of EAU.

[Galactose-1-phosphate uridyl transferase and congenital cataract]

The activity of red blood cells galactose-1-p-uridyl transferase (GPUT) was determined by the spectrophotofluorometric method. The average GPUT activity in 102 control subjects was 13. 34 +/- 2. 03u. There were no differences in the sexes and ages. The average GPUT activity in 108 patients with congenital cataract was 11.58 +/- 4. 03u and was lower than that of the controls (P < 0.01). The GPUT activity in 14 of the 108(12.96%)patients was all-3SD below the mean value of the controls (< 7.24u) and the range was from 4.02u to 7.13u with the mean value of 5. 93u being about 44.45% of the normal. The difference between the two groups was statistically significant (P < 0.001). The results indicated that some of the patients with congenital cataract were due to decrease in the GPUT activity. The patients with decrease GPUT activity were mainly suffering from cataracts and their systemic disease were mild.

HLA antigens and Vogt-Koyanagi-Harada's disease

Thirty patients with Vogt-Koyanagi-Harada's disease were typed for HLA-A and HLA-B antigenic determinants by a microlymphocytotoxicity technique. HLA-B22 antigen showed an increased frequency of 43.3% in the patient group (relative risk = 8.69; exact P < 0.0001; corrected P < 0.0025) compared with normal control group (frequency = 7.69%). This association suggests that immunogenetic factor may play an important role in the pathogenesis of Vogt-Koyanagi-Harada's disease.

Inhibition of rat lens aldose reductase by quercetagetin and patuletin

In this paper the results of inhibition of the Aldose reductase (AR) activity on Wistar rat lens by Quercetagetin extracted from Tagetes erects Linn and by Patuletin extracted from Tagetes patula Linn are reported. Quercetagetin inhibited AR of the rat lens by 93.9% at 10(-4) M, 76.0% at 10(-5) M and 13.3% at 10(-6) M. Patuletin inhibited AR of the rat lens by 100% at 10(-1) M, 80% at 10(-5) M and 22.7% at 10(-6) M respectively. The results show that these two flavones are lens AR Inhibitors, but further study should be done for the possibility of clinical application.

Hexokinase, glucose-6-phosphatase dehydrogenase and aldose reductase in human fetal lenses

The lens HK, G6PD, AR activity and its relationship with fetal age was determined. There is a positive correlation between the age of fetus and the activity (IU/mg pro.) of HK and G6PD (r = 0.8069, 0.8204, P < 0.01) and a negative correlation between the age of fetus and activity of AR (r = -0.810 1, 0.05 > P > 0.01).

[Visual pigment genes for color vision defects]

Applying recombinant DNA techniques, the structures of red pigment gene (RPG) and green pigment gene (GPG) were analyzed for 43 patients with protan or deutan (including 3 females), 4 normal relatives and 3 carriers out of 3 families, as well as 11 normal controls. Abnormality of RPG was detected in all 19 protan and that of GPG was found in 14 out of 24 deutan. In about 80% (32/40) of protan and deutan the changing of exon 5 for RPG or GPG was discovered. In protan the normal RPG was replaced by a 5' red -3' green hybrid gene. Some of the deutan had no GPG, some had 5' green -3' red hybrid gene with or without GPG. Furthermore, the exon 5 of RPG and GPG was amplified by polymerase chain reaction (PCR) and further analyzed by Rsa I digestion. The results for PCR are identical to that of Southern blot hybridization.

[Visual pigment genes for color vision defects]

Applying recombinant DNA techniques, the structures of red pigment gene (RPG) and green pigment gene (GPG) were analyzed for 43 patients with protan or deutan (including 3 females), 4 normal relatives and 3 carriers out of 3 families, as well as 11 normal controls. Abnormality of RPG was detected in all 19 protan and that of GPG was found in 14 out of 24 deutan. In about 80% (32/40) of protan and deutan the changing of exon 5 for RPG or GPG was discovered. In protan the normal RPG was replaced by a 5' red -3' green hybrid gene. Some of the deutan had no GPG, some had 5' green -3' red hybrid gene with or without GPG. Furthermore, the exon 5 of RPG and GPG was amplified by polymerase chain reaction (PCR) and further analyzed by Rsa I digestion. The results for PCR are identical to that of Southern blot hybridization.

[Primary study of iontophoresis of zinc ion in treatment of retinitis pigmentosa]

We report here the preliminary effects of zinc iontophoresis in treatment of 26 Rp patients who had decreased zinc serum level or abnormal ratio of serum copper to zinc. Through more than 20 to 30 times of therapy, the vision of 15.38% eyes increased more than "3 lines", 4% eyes increased more than 5 degrees in the visual field, 13.46% eyes improved in dark adaptation threshold (greater than 1.0), the visual functions of the rest eyes were slightly improved or unimproved. The fundus didn't change before & after treatment. There were no changes of ERG in 8 eyes of 4 cases. In addition, the advantages and disadvantages between Zn iontophoresis and Zn compound taken orally, the improvement of vision by direct electric current therapy, the relationship between the metabolism of Zn element and Vit A and influence of Zn over the mechanism of dark adaptation were also briefly discussed.