[Mechanisms of early gastro-intestinal ischemia after burn: hemodynamic and hemorrheologic features]

OBJECTIVE

To study the mechanisms of early gastro-intestinal ischemia developed in acute burn period and its relationships with hemodynamic and hemorrheologic changes.

METHODS

Twelve pigs were randomly allocated into two groups: group C, a sham group that was subjected to all surgical procedures except burn; group B, 30% TBSA cutaneous thermal injury, and was resuscitated with Parkland formula one hour after burn.

RESULTS

MAP remained stable after burn, but RAP, MPAP, PAWP and CI decreased significantly to the lowest level 4-8 hours after burn, and recovered after resuscitation 24 hours postburn. Intramucosal pH declined immediately (1 hour after burn) and remained abnormal throughout observation period. Portal venous blood flow demonstrated similar changes as pHi, and correlated well with intestinal pHi. Whole blood viscosity and plasma viscosity in portal venous blood elevated obviously after burn.

CONCLUSIONS

1. GI ischemia occurred early and recovered slowly during burn shock phase with conventional resuscitation regime. 2. GI ischemia correlated significantly with portal venous blood flow, but did not with systemic hemodynamic variables. 3. Hemorheologic changes in portal venous blood may exaggerate ischemia injuries.

Cytotoxicity of hemolytic, cytotoxic necrotizing factor 1-positive and -negative Escherichia coli to human T24 bladder cells

Approximately one-half of Escherichia coli isolates from patients with cystitis or pyelonephritis produce the pore-forming cytotoxin hemolysin, a molecule with the capacity to lyse erythrocytes and a range of nucleated cell types. A second toxin, cytotoxic necrotizing factor 1 (CNF1), is found in approximately 70% of hemolytic, but rarely in nonhemolytic, isolates. To evaluate the potential interplay of these two toxins, we used epidemiological and molecular biologic techniques to compare the cytotoxicity of hemolytic, CNF1(+), and CNF1(-) cystitis strains toward human T24 bladder epithelial cells in vitro. A total of 29 isolates from two collections of cystitis-associated E. coli were evaluated by using methylene blue staining of bladder monolayers at 1-h intervals after inoculation with each strain. Most (20 of 29) isolates damaged or destroyed the T24 monolayer (less than 50% remaining) within 4 h after inoculation. As a group, CNF1(+) isolates from one collection (11 strains) were less cytotoxic at 4 h than the CNF1(-) strains in that collection (P = 0.009), but this pattern was not observed among isolates from the second collection (18 strains). To directly evaluate the role of CNF1 in cytotoxicity of hemolytic E. coli without the variables present in multiple clinical isolates, we constructed mutants defective in production of CNF1. Compared to the CNF1(+) parental isolates, no change in cytotoxicity was detected in these cnf1 mutants. Our results indicate that CNF1 does not have a detectable effect on the ability of hemolytic E. coli to damage human bladder cell monolayers in vitro.

Existence of striatal nerve cells coexpressing CCK(B) and D2 receptor mRNAs

Co-localization of CCK(B) and D2 receptor mRNAs was analysed in adjacent sections of nucleus caudate putamen of the rat by means of in situ hybridization. A distinct subpopulation of D2 mRNA containing striatal nerve cells (in the order of 10%) was shown to co-express CCK(B) and D2 receptor mRNAs. All the CCK(B) receptor mRNA-positive nerve cells were co-localized with D2 receptor mRNA. These results give one morphological substrate to the previously demonstrated CCK(B)/D2 receptor interactions in the striatum.

Electrospray mass spectrometry studies of non-heme iron-containing proteins

The oligomeric state and the metal atom stoichiometry of a series of non-heme iron-containing, multimeric proteins have been measured using electrospray ionization (ESI) in a time-of-flight (TOF) mass spectrometer. The proteins were obtained both from natural sources and by overexpression of recombinant DNA in Escherichia coli. ESI-TOF mass spectra of the metalloproteins present in nondenaturing solutions exhibit peaks corresponding to the multimeric forms of the holoproteins containing the expected number of metal atoms. Capillary-skimmer dissociation of the holoproteins produces a series of ions, which allows an exact count of the number of metal atoms present in each subunit, and also provides an indication of the oxidation state of the metal atoms. Two recombinant proteins, Phascolopsis gouldii hemerythrin (Pg-Hr) and Desulfovibrio vulgaris rubrerythrin (Dv-Rr), have been examined as well as hemerythrin isolated from Lingula reevii (Lr-Hr). ESI-TOF measurements of the aqueous solution of Pg-Hr at pH 6 yields ions of mass 108,783 Da, in close agreement with the calculated average molecular mass of an intact octameric holoprotein. Capillary-skimmer dissociation of the ions of the holoprotein produces a mass spectrum that contains peaks corresponding to a low m/z monomer and a high m/z heptamer. The masses of the monomer ions produced in this manner are assigned to the aposubunit, [subunit + Fe - 3H]+, and [subunit + 2Fe - 6 H]+. Naturally occurring Lr-Hr is composed of two subunits with average molecular masses measured under denaturing conditions by ESI-TOF to be 13,877.0 Da for the alpha-subunit and 13,517.5 Da for the beta-subunit. Under nondenaturing conditions, a multimeric species with a molecular weight of 110,663 Da is measured by ESI-TOF, corresponding to an alpha 4 beta 4 octamer. Capillary-skimmer dissociation of the alpha 4 beta 4 oligomer produces ions corresponding to both types of monomers (alpha and beta) and the corresponding heptamers (alpha 3 beta 4 and alpha 4 beta 3). In ESI-TOF measurements of recombinant rubrerythrin Dv-Rr using nondenaturing conditions, the principal ion observed corresponds to a homotetramer with an average molecular mass of 86,844 Da. Capillary-skimmer dissociation of the rubrerythrin tetramer leads to formation of a series of peaks corresponding to the subunit of the apoprotein and to subunits containing from one to three specifically bound iron atoms.

Effects of radiation on wound healing

The pathological changes of radiation on wound healing in rats were observed by macroscopic, microscopic, and electronmicroscopic examination and detection of collagen types. We found that the wound healing process was obviously delayed by irradiation. First, the early phase inflammatory response was severely inhibited. In particular, the number of infiltrating macrophages and neutrophils was decreased, blood vessels were injured, and hemorrhage was evident. Second, the formation and maturation of granulation tissue were slowed down, fibroblasts were injured, and transcription of types and collagen mRNAs and synthesis and secretion of collagen were reduced. Finally, the reepithelialization process was delayed and the healing time was prolonged.

Kinetic alterations of angiotensin-II and nitric oxide in radiation pulmonary fibrosis

We studied the kinetic alterations of angiotensin-II (A-II) and nitric oxide (NO) in radiation pulmonary fibrosis (RPF) to determine the roles of these two types of vasoactive substances in the pathogenesis of RPF. We irradiated the right hemithorax of male Wistar rats with single doses of 0, 15, and 30 Gy of 60Co gamma rays and we examined the lung parenchyma at 1, 3, 5, and 7 months following the radiation. The rats were killed at the stated intervals and samples were obtained from the right lung. We measured types I and III procollagen mRNA by in situ hybridization and demonstrated the synthesis and distribution of A-II in the pulmonary tissue by immunohistochemistry. The formation and kinetic alterations of types I and III collagen were analyzed under polarized light microscope using Sirius Red stain. The hydroxyproline (Hyp) content was measured in the pulmonary tissue after digestion with HCl. A-II radiation immunoactivity (RIA) was assayed in pulmonary tissue homogenate. Pulmonary NO content, NO synthase (NOS), and the angiotensin converting enzyme (ACE) activities were also measured. Our results showed that types I and III collagen genes began to be expressed 1 month after irradiation. Type I collagen gene increased significantly, reaching its peak 3 months after irradiation. As the irradiation dosage was increased from 15 to 30 Gy, the type I collagen gene content increased significantly, while type III significantly decreased. The Hyp content increased with the passage of time after irradiation. Pulmonary A-II RIA increased significantly with the dose of irradiation and was chiefly produced by fibroblasts and macrophages in the interstitium, bronchiolar epithelium, and the anteriolar wall. Pulmonary NO and NOS activities decreased following irradiation. One month following irradiation, the expression of the type I collagen gene begins to increase, with a significant increase in both Hyp and type I collagen 3 months after irradiation. The histogenesis of RPF may be related to A-II. The interstitial cells, the bronchiolar epithelium, and the arteriolar wall can produce A-II and need not pass through the ACE pathway. Our results suggest that the A-II increase and NO decrease may have a role in the pathogenesis of RPF.

The protective action of taurine and L-arginine in radiation pulmonary fibrosis

Taurine has the ability to resist the action of oxygen-free radicals by protecting cytomembranes. L-arginine increases the nitric oxide in the organism, inhibiting some types of abnormal cell proliferation. We examined the actions and protective mechanisms of these two substances against radiation pulmonary fibrosis. The mRNA transcription and the distribution of pulmonary types I and III procollagen were measured by in situ hybridization. Type I and type III collagen in the interalveolar septa and the change ratio between the two types were assayed using Sirius Red staining and polarizing microscopy. Angiotensin converting enzyme (ACE), hydroxyproline (Hyp), malondialdehyde (MDA), and nitric oxide (NO) were measured in lung tissue after irradiation. We found that, following administration of taurine or arginine, the mRNA transcription of procollagen types I and III significantly decreased in the pulmonary tissue 3 months after irradiation and the Hyp content was lower, especially after the administration of arginine. The extent of the radiation-induced decrease in ACE activity was markedly attenuated. As a substrate of NO production, arginine can significantly increase the pulmonary NO content. We conclude that the administration of taurine or arginine can significantly decrease the mRNA transcription of procollagen and the synthesis of type I collagen in the interalveolar septa and can decrease the Hyp content of the pulmonary tissue. Following irradiation, NO can attenuate the radiation-induced decrease in ACE activity. Our study suggests that exogenous NO and taurine significantly protect against radiation pulmonary injury.

Preventive effects of selenium-enriched spiruline (SESP) on radiation pneumonitis

We studied the early effects of selenium-enriched spiruline (SESP) on radiation-induced pulmonary fibrosis using histopathology, cDNA-mRNA dot-blot hybridization, and a biochemical technique for quantifying the hydroxyproline content. We found marked lung injury in the irradiated group, whereas only slight hyperemia, hemorrhage, exudation, and thickness of the interalveolar wall in the lung in the selenium-treated group. The hydroxyproline (hyp) content in the lungs and the synthesis of type III collagen mRNA decreased in the SESP-treated group. Selenium-enriched spiruline may have a protective effect on the development of radiation pneumonitis.

Association of SET domain and myotubularin-related proteins modulates growth control

Several proteins that contribute to epigenetic mechanisms of gene regulation contain a characteristic motif of unknown function called the SET (Suvar3-9, Enhancer-of-zeste, Trithorax) domain. We have demonstrated that SET domains mediate highly conserved interactions with a specific family of proteins that display similarity with dual-specificity phosphatases (dsPTPases). These include myotubularin, the gene of which is mutated in a subset of patients with X-linked myotubular myopathy, and Sbf1, a newly isolated homologue of myotubularin. In contrast with myotubularin, Sbf1 lacks a functional catalytic domain which dephosphorylates phospho-tyrosine and serine-containing peptides in vitro. Competitive interference of endogenous SET domain-dsPTPase interactions by forced expression of Sbf1 induced oncogenic transformation of NIH 3T3 fibroblasts and impaired the in vitro differentiation of C2 myoblast cells. We conclude that myotubularin-type phosphatases link SET-domain containing components of the epigenetic regulatory machinery with signalling pathways involved in growth and differentiation.

The spread and uptake pattern of intracerebrally administered oligonucleotides in nerve and glial cell populations of the rat brain

The fate of 15-mer phosphorothioate-modified antisense oligonucleotides to c-fos was followed after their microinjection into rat brain. Using radiolabeled oligonucleotides, it was demonstrated that the bulk of the material stays in the injected region but that a minor part is transported with the projection pathways to regions far away from the site of injection. Using tetramethylrhodamine-isothiocyanate (TRITC) labeling as well as fluorescein isothiocyanate (FITC) labeling, it was found that the oligonucleotides were taken up by a great number of cells within 30 minutes after the injection. A diffuse cytoplasmic staining and also nuclear staining were observed in these cells, which could be identified exclusively as neurons by double labeling for the neuron-specific protein NeuN. At later times (6, 24, and 48 hours), the appearance of the oligonucleotides changed gradually to a punctate cytoplasmic staining, which by electron microscopic analysis was shown to be caused by the presence of the oligonucleotides in intracellular vesicles. The pattern of intracellular fluorescence was changed when the oligonucleotides were injected together with the cationic lipid 1,2-bis(oleoyloxy)-3-(trimethylammonio)propane (DOTAP). A small number of astrocytes and microglial cells were found to be labeled by the oligonucleotides, but only at later times after the injection and exclusively in a punctate cytoplasmic manner. Thus, the uptake of oligonucleotides in the nerve and glial cell populations of the brain might involve different mechanisms, the one in the neurons appearing to be very rapid and potent.

Transmission and natural regulation of infection with Ascaris lumbricoides in a rural community in China

A longitudinal study on a cohort of 215 people who remained untreated from June 1993 to June 1994 was carried out using fecal egg counts to examine the course of transmission and aspects of the natural regulation of the infection with Ascaris lumbricoides. The results indicate that the parasite population remained relatively stable during the years since overall prevalence remained steady above 60%. About 40% of the people in the cohort retained their infection intensity status throughout the year, in terms of light, medium, and heavy infections. The regulation of infection in the population could be attributed to the tendency for the loss of worms from people with initial light infections and the movement to medium infection intensity status of people with both light and heavy infections. Compared with adults, children showed a stronger tendency of retaining initial medium infections but weaker tendencies for keeping initial light infections and clearing themselves of infection. Predisposition to light and medium infections was detected in people who had experienced an uninfected period of 4-12 mo before reinfection was established.

[Studies on control of root rot on Panax notoginseng]

Chemical Control tests of pot, plot and field for Panax notoginseng root rot were conducted during 1995-1996. The results indicated that the chemical control is a effect measure to control rapidly occurring and spreading of Panax notoginseng root rot. It was the best treatment to coordinate use of bactericide and fungicide, obviously better than alone or mixed use of fungicide and also better than alone use of bactericide. In the pot and plot tests, the best coordinate treatment was the treatment of 10% phenazine plus 70% dexon plus 50% bavistin and plus water (1:1:500), the control effect was 70%; in the field test, the control effect of over 70% was also get with the treatment of 10% phenazine plus 70% dexon and plus small soil (1 Kg:1 Kg:150 Kg) per mu.

Segmental defect of the intestinal musculature associated with ileal atresia and biliary atresia

A full-term baby boy with a segmental defect of the ileal musculature associated with terminal ileal and biliary atresia is presented. The newborn had a dilated loop of the ileum 30 cm proximal to the ileal atretic site. Pathological study results showed absence of the intestinal musculature with relatively intact mucosa. Foci of recent muscular necrosis were found in the lesion. One month later, relaparotomy was performed because of persistent jaundice and hepatic duct atresia was confirmed. Segmental defect of the intestinal musculature associated with ileal atresia and biliary atresia has not been reported in the literature. The authors emphasize that in the management of this unusual defect, one should pay attention to the multiple associated malformations.

[Influence of seedling assortment on Panax notoginseng growth and yield]

Making Panax notoginseng seedling assortment according to seedling size before transplanting, the result shows that the influence is better, the yield of root tuber and fruit is higher. Culturing good seedling is the fundamental measure to increase yield of P. notoginseng.

Thyroid hormone induces beta1-adrenergic receptor gene transcription through a direct repeat separated by five nucleotides

Transcription of the rat gene for the beta1-adrenergic receptor (beta1-AR) is stimulated by thyroid hormone (T3) in ventricular myocytes. To identify the domains involved in the regulation of beta1-AR gene transcription by T3, three kb of 5'-flanking sequence of the rat beta1-AR gene were ligated to a luciferase reporter gene and transiently transfected into ventricular myocytes. By generating deletions in the rat beta1-AR promoter, a region between -125 and -100 was found to mediate a three-fold induction by T3. This element was able to confer T3 responsiveness to a neutral promoter driving the luciferase reporter gene. Through site directed mutagenesis of this region, it was determined that the T3 responsive element (TRE) was organized as a direct repeat separated by five nucleotides in which the 5'-most AGGTCG half-site was between nucleotides -105 to -102 and the 3'-most AGGTCA half-site between nucleotides -116 and -113. Both the thyroid hormone receptor isoforms alpha and beta bound to the oligomer representing the sequences between -125 and -100 most efficiently as heterodimers with the retinoid X receptor. This TRE is unusual in that it is a direct repeat separated by five nucleotides which is located 3' to the transcriptional start site.

[Observation on human embryonic lung fibroblast proliferation mediated by mitogen activated protein kinase]

OBJECTIVE

To study the effect of mitogen activated protein kinase (MAPK) on the proliferation of human embryonic lung fibroblast (HELF) induced by 60Co irradiation and the relationship between MAPK and angiotensin II (A II).

METHODS

Cell proliferation was measured with enzyme-labeling method; angiotensin II, MAPK and type I precollagen synthesis as well as the role of sodium nitroprusside on the inhibition of A II were evaluated adopting immunohistochemical technique combined with image analysis after 1-5 Gy 60Co gamma-ray irradiation on the cultured HELF.

RESULTS

Irradiation at 1-5 Gy promoted cell proliferation and type I precollagen synthesis; the syntheses of A II and MAPK were also increased in the irradiated cells. Exogenous A II enhanced cell proliferation, but sodium nitroprusside inhibited the action of A II.

CONCLUSIONS

HELF proliferation induced by 60Co irradiation is a chain reactive course, in which, A II and MAPK are involved. MAPK may play a role of limiting valve in the signal transduction of cellular proliferation.

[Experimental comparison of two coxsackievirus B3 variants in murine myocardial cells]

There is lack of direct evidence whether the myocarditis can be induced by CVB3o. The two coxsackievirus B3 variants were used to infected murine myocardial cells. The results showed that: (1) In culture medium of murine myocardial cells infected with two variants, it did not show much differences in titers at 12 and 24 hours between CVB3o and CVB3m. (2) The two variants could all induce the death of myocardium, but with the elapse of time, the cell death rate of CVB3m infected cells was much higher than CVB3o. (3) CVB3o could not block the myocardial cells from infection by CVB3m. It is concluded that myocardial cells can be infected by CVB3o, but the degree of infection is lower than CVB3m.

[A simple nitric oxide exposure system for small animals]

A nitric oxide exposing system was designed for experimental research, which consist of equipments such as plexiglass chamber, blower, flowmeter, NO/N2 cylinder, pure O2 cylinder, NOx analyzer, and O2/CO2 monitor. The efficacy of the whole system has been verified through our practice as shown by the following results: measured NO inside the chamber were close to designed NO concentration, measured O2 concentrations in the chamber were similar to that of the atmosphere, and the highest nitrogen dioxide (NO2) and carbon dioxide (CO2) concentrations were lower than 3 ppm and 0.3% respectively. The experimental facility is simple in construction, easy to be operated and convenient for research on effects and toxicity of long-term inhaled nitric oxide in small animals.

Discriminating between allelic and interlocus differences among human immunoglobulin VH4 sequences by analyzing single spermatozoa

To address the challenging issue of distinguishing allelic and interlocus differences among repetitive sequences, human immunoglobulin VH4 loci in the parental haplotypes of 13 donors were determined by analyzing single spermatozoa. VH4 sequences detected among these donors were assigned to their corresponding loci based on the fact that allelic sequences usually segregate into different gametes. Four out of the ten VH4 loci were shown to contain null alleles that are undetectable with diploid materials. The distribution of the allelic variation within the analyzed regions at the VH4 loci is highly biased.

ALK, the chromosome 2 gene locus altered by the t(2;5) in non-Hodgkin's lymphoma, encodes a novel neural receptor tyrosine kinase that is highly related to leukocyte tyrosine kinase (LTK)

Anaplastic Lymphoma Kinase (ALK) was originally identified as a member of the insulin receptor subfamily of receptor tyrosine kinases that acquires transforming capability when truncated and fused to nucleophosmin (NPM) in the t(2;5) chromosomal rearrangement associated with non-Hodgkin's lymphoma, but further insights into its normal structure and function are lacking. Here, we characterize a full-length normal human ALK cDNA and its product, and determine the pattern of expression of its murine homologue in embryonic and adult tissues as a first step toward the functional assessment of the receptor. Analysis of the 6226 bp ALK cDNA identified an open reading frame encoding a 1620-amino acid (aa) protein of predicted mass approximately 177 kDa that is most closely related to leukocyte tyrosine kinase (LTK), the two exhibiting 57% aa identity and 71% similarity over their region of overlap. Biochemical analysis demonstrated that the approximately 177 kDa ALK polypeptide core undergoes co-translational N-linked glycosylation, emerging in its mature form as a 200 kDa single chain receptor. Surface labeling studies indicated that the 200 kDa glycoprotein is exposed at the cell membrane, consistent with the prediction that ALK serves as the receptor for an unidentified ligand(s). In situ hybridization studies revealed Alk expression beginning on embryonic day 11 and persisting into the neonatal and adult periods of development. Alk transcripts were confined to the nervous system and included several thalamic and hypothalamic nuclei; the trigeminal, facial, and acoustic cranial ganglia; the anterior horns of the spinal cord in the region of the developing motor neurons; the sympathetic chain; and the ganglion cells of the gut. Thus, ALK is a novel orphan receptor tyrosine kinase that appears to play an important role in the normal development and function of the nervous system.

The HRX proto-oncogene product is widely expressed in human tissues and localizes to nuclear structures

Chromosomal rearrangement of the HRX (MLL, ALL-1, Htrx) gene situated at chromosome band 11q23 is one of the most frequent genetic changes in infant leukemias of myeloid and lymphoid lineage and in treatment-induced secondary leukemias. The HRX gene codes for a predicted 431-kD protein that shows significant homology to the Drosophila trithorax protein, an Hox epigenetic regulator. Typically, the region encoding the HRX gene is rearranged, mostly in reciprocal translocations with a number of partners, resulting in a range of fusion genes. However, this is not the only abnormality affecting HRX because partial duplication of the gene, as well as interstitial deletions, can occur. Despite extensive studies of HRX at the genetic level, the protein products of the HRX gene and their patterns of expression in normal and leukemic cells remain uncharacterized. In this study we analyzed the distribution and localization of HRX proteins in cell lines and human tissues, using both polyclonal and monoclonal antibodies. The specificity of these reagents was confirmed using cells transfected with the HRX-ENL fusion gene. Western blot analyses of protein extracts from cells carrying the t(11;19) and t(4;11) translocations showed HRX chimeric proteins whose migrations corresponded to the sizes predicted from analyses of translocation-induced fusion mRNAs expressed by the derivative 11 chromosomes. Immunocytochemical analysis showed a punctate distribution of wild-type and chimeric HRX proteins within cell nuclei, suggesting that HRX localizes to nuclear structures in cells with and without 11q23 translocations. Nuclear staining was found in the majority of tissues studied with the strongest reactivity in cerebral cortex, kidney, thyroid, and lymphoid tissues. Thus, HRX is widely expressed in most cell types including hematopoietic cells, a finding that precludes an immunocytochemical approach for diagnosis of leukemias bearing 11q23 structural abnormalities.

[Studies on cell senescence induced by D-galactose in cultured neurons and fibroblasts]

The cell senescence induced by D-galactose (D-gal) in cultured rat fetal brain neurons and human fetal lung fibroblast was investigated in vivo and in vitro. The results showed pronounced decreases in nerve cell diameters, number of process and percentage of multiprocess neurons including "pyramidal" and "stellate" shaped and a rather high level of mortality rate observed in D-gal-treated (8 g/L) neurons. Lessening of the proliferating population of lung fibroblast taken from rat treated with D-gal (50 mg/kg.d, subcutanous injection for 6 weeks) was observed. We have also determined the changes of cell cycle in human fetal lung fibroblast cells treated with D-gal (8 g/L): the proportion of the G0-G1 cells increased but the G2-M and DNA level and the results showed that decreased and the cell growth rate declined in comparison with those of the control. Lipid peroxidation was observed in both kinds of cells because D-gal was proved to have action of decreasing SOD activity and increasing MDA content, the results found in D-gal-treated rats were similar to those observed in hypoxanthine-xanthine oxidation reaction system (O2-), indicating that reactive oxygen was generated in the course of D-gal metabolism. It is concluded that D-gal has the hastening effect on cell senescence and oxidative stress might be responsible for this aging effect.

[Effect of cigarette smoking on lipid peroxidation and antioxidation in rat lens]

The effects of cigarette smoking on lipid peroxidation, the activities of antioxidases, and the level of non-protein sulphydryl group in the rat lenses were investigated. The results showed that compared with the control group, MDA contents were significantly higher, while the wet weight of lenses, the concentration of non-protein sulphydryl group, the activities of superoxide dismutase and glutathione peroxidase were significantly decreased in the smoking rats. This study suggested that cigarette smoking might be involved in the development of cataract.

Promoter analysis of the rat beta1-adrenergic receptor gene identifies sequences involved in basal expression

The beta1-adrenergic receptor (beta1-AR) mediates several functions of catecholamines in the heart, including the stimulation of heart rate and contractility. The expression of the rat beta1-AR gene was assessed by transiently transfecting chimeric genes containing the beta1-AR promoter, driving the luciferase reporter gene into various cell lines. beta1-AR/luciferase vectors containing 3 kb of the 5'-flanking region and extending to -126 relative to the start site of translation were expressed at high levels in ventricular myocytes, SK-N-MC cells, and HepG2 cells. The addition of 26 nucleotides from -125 to -100 to the -3311 beta1-AR/luciferase chimeric gene reduced expression in myocytes and SK-N-MC cells while eliminating expression in HepG2 cells. This element is located 125 base-pairs 3' to the transcriptional start site. The mutation of four nucleotides between -121 and -118 diminished the inhibitory effect of this element. The inhibitory activity of the -125 to -100 sequence was completely dependent on promoter context and positioning. In addition to this 3' element, sequences between -3311 and -2740 in the 5'-flanking region of the beta1-AR gene were required for the full transcriptional suppression. Using DNase I footprinting and gel mobility assays, it was determined that within the 26-bp region, rat heart nuclear proteins bound to two sites between nucleotides -123 and -112 and -106 and -100. Therefore, appropriate basal expression of the beta1-AR gene involves widely separated sequences 3' and 5' to the transcriptional start site.

Detection of the t(2;5)(p23;q35) and NPM-ALK fusion in non-Hodgkin's lymphoma by two-color fluorescence in situ hybridization

The non-Hodgkin's lymphoma (NHL) subset commonly referred to as large cell lymphoma (LCL) has historically been characterized by it's marked cytological, immunological, and clinical heterogeneity. One potential defining feature of these lymphomas, the t(2;5)(p23;q35), occurs in 25% to 30% of anaplastic LCLs and is also found in cases with diffuse large cell or immunoblastic morphology. We recently identified nucleophosmin (NPM) and anaplastic lymphoma kinase (ALK) as the genes on chromosomes 5 and 2, respectively, that are juxtaposed by this translocation. To provide a complementary approach to the use of classical cytogenetics or polymerase chain reaction-based methods for the detection of this abnormality, we have developed a two-color fluorescent in situ hybridization (FISH) assay for the t(2;5) that may be used for the analysis of both interphase nuclei and metaphase chromosomes. Three overlapping chromosome 5 cosmid clones located immediately centromeric to the NPM gene locus and an ALK P1 clone located telomeric to the chromosome 2 breakpoint were labeled with digoxigenin or biotin, respectively, and used to visualize the derivative chromosome 5 produced by the t(2;5), evident as juxtaposed or overlapping red and green fluorescent signals. This NPM-ALK FISH assay was initially validated by analysis of a series of cytogenetically characterized cell lines, with the presence of the der(5) chromosome showed specifically only in those lines known to contain the t(2;5). The assay was then applied in a blinded fashion to a series of eight cytogenetically t(2;5)-positive clinical specimens and seven known t(2;5)-negative cases, including three NHL and four Hodgkin's disease biopsy samples. Whereas the t(2;5)-negative cases were negative by FISH, all eight t(2;5)-positive cases were positive. One additional case, initially thought to be positive for the translocation by cytogenetics, was proven to not be a classic t(2;5) by interphase and metaphase FISH. These data indicate that the FISH assay described is a highly specific and rapid test that should prove to be a useful adjunct to the currently available methods for detection of the t(2;5).

Ascaris, people and pigs in a rural community of Jiangxi Province, China

A longitudinal investigation on natural populations of Ascaris in humans and pigs and an investigation of soil contamination with Ascaris eggs were carried out from June 1993 to June 1994 in 2 villages, Manhu area, Xinjian County, Jiangxi Province, China. Results from these studies indicate that although human ascariasis is endemic there is significant fluctuation in both prevalence and the mean number of eggs/g faeces (epg) of the communities. Fluctuation of age-stratified prevalence and mean epg was detected in children but not in most adult groups. Most cases of human ascariasis were judged to involve low intensities of infection and a typical overdispersion distribution pattern was observed through the year. It was estimated that during the year, nearly half of the eggs discharged in the environment came from infections in children aged between 2 and 15 years which accounted for about 30% of the total population. Soil in and around houses and in vegetable gardens was found to be contaminated by Ascaris eggs and this situation remained relatively stable throughout the year. Monthly developmental rate of Ascaris eggs in soil was detected and the results suggest that the fluctuation in prevalence observed during the year should be directly attributed to the effect of seasonality of egg development. Features of Ascaris infection in pigs were found to be similar to those in humans except for a lower mean intensity of infection. The possibility of cross-infection of Ascaris between human and pig hosts is discussed.

[The laboratory study on biofragmentable anastomosis rings (BAR) in gastrointestinal tract reconstruction]

To study and investigate the feasibility of biofragmentable anastomosis ring (BAR) for gastrointestinal (GI) tract reconstruction, we performed gastroenterostomy in 34 dogs. BAR anastomoses were performed with proper outer diameter and gape size in small bowel in 8 cases, in large bowel in 11 cases, in esophagus in 12 cases, in esophago-intestinal in 2 cases, in gastrojejunum in 1 cases. The postoperative serial X-ray examinations showed that BAR maintained good integration two weeks postoperation. The ring disintegrated into several small fragments that passed out of the body in feces from the 14th postoperative day after surgery. All of the dogs were killed on the 28th operative day and autopsied. The anastomosis site had smooth serosa and scar membrane in gross and were substituted by regenerative fibrous tissue. The specimen barim-air double contrast X-ray revealed that GI tract was coherent without leakage and stenosis. Therefor, the authors recognized that BAR can be recommended as a safe technique in GI operation.

Special configuration of a very large Schmidt telescope for extensive astronomical spectroscopic observation

A special reflecting Schmidt telescope is used to observe celestial objects. The telescope has an aperture of 4m, f ratio of 5, and a 5° field of view. Its optical axis is fixed and tilted 25° to the horizontal that runs from south to north. The celestial objects were observed for 1.5 h as they passed through the meridian. The shape of the reflecting Schmidt plate has to be changed with each different declination δ and in the tracking process. This is achieved with active optics. The sky area to be observed is -10° ≤ δ ≤ +90°. There are plans to place ~4000 optical fibers on the telescope focal surface that will lead to a dozen spectrographs.

[Detection of konjac glucomannan in seven Amorphophallus Blume species]

Seven Amorphophallus species were detected for konjac glucomananam (KGM). It has been found out that A. albus, A. konjac, A. yuloensis, A. xemengensis and A. dunnii are of higher contents of KGM (30%), but A. sinensis and A. yunnanensis are not as further comfirmed by TLC analysis. It follows that A. albus, A. konjac, A. yuloensis, A. xemengensis and A. dunnii are high quality resources of KGM, but A. sinensis and A. yunanensis cannot be used as substitutes for the above-cited five species.

The gene encoding LERK-7 (EPLG7, Epl7), a ligand for the Eph-related receptor tyrosine kinases, maps to human chromosome 5 at band q21 and to mouse chromosome 17

The eph-related receptors are the largest subfamily of receptor tyrosine kinases. Recently, we and others have identified seven different, but related, cDNAs encoding membrane-bound ligands for this family of receptors. One member, LERK-7, is attached to the cell membrane via glycosyl-phosphatidylinositol linkage and has been found to be a ligand for the eph-family receptors hek, elk, eck, and rek. Using PCR-based screening of human x rodent somatic cell hybrid DNAs, we have assigned the gene that encodes LERK-7 (EPLG7) to human chromosome 5. Fluorescence in situ hybridization to metaphase chromosome preparations using a genomic clone from the locus refined this localization to chromosome 5, band q21. In addition, Southern blot analysis of DNAs from interspecific backcross mice indicated that the mouse homologue Epl7 maps to a homologous region on chromosome 17.

The rf2 nuclear restorer gene of male-sterile T-cytoplasm maize

The T cytoplasm of maize serves as a model for the nuclear restoration of cytoplasmic male sterility. The rf2 gene, one of two nuclear genes required for fertility restoration in male-sterile T-cytoplasm (cmsT) maize, was cloned. The protein predicted by the rf2 sequence is a putative aldehyde dehydrogenase, which suggests several mechanisms that might explain Rf2-mediated fertility restoration in cmsT maize. Aldehyde dehydrogenase may be involved in the detoxification of acetaldehyde produced by ethanolic fermentation during pollen development, may play a role in energy metabolism, or may interact with URF13, the mitochondrial protein associated with male sterility in cmsT maize.

A [2Fe-2S] protein encoded by an open reading frame upstream of the Escherichia coli bacterioferritin gene

An open reading frame located upstream of the bacterioferritin gene in Escherichia coli encodes a hypothetical 64-residue protein [Andrews, S.C., Harrison, P.C., & Guest, J.R. (1989) J. Bacteriol. 171, 3940-3947)]. The spacing of the four cysteine residues in this hypothetical protein is identical to that in a region of NIFU, a [2Fe-2S] protein found in nitrogen-fixing bacteria [Fu, W., Jack, R.F., Morgan, T.V., Dean, D.R., & Johnson, M.K. (1994) Biochemistry 33, 13455-13463)]. The NIFU-like E. coli gene was cloned and overexpressed with a C-terminal "His tag" in E. coli using the T7 RNA polymerase/promoter system, and the protein was purified by metal-chelate affinity chromatography. UV-vis absorption and EPR spectra together with iron and amino acid analyses conclusively established that this NIFU-like E. coli protein contains one [2Fe-2S] cluster which can exist in at least two oxidation levels: +2 for the as-purified protein, and +1 for dithionite-reduced protein. Size-exclusion chromatography established that this His-tagged [2Fe-2S] protein is monomeric in solution. Affinity chromatography demonstrated specific complex formation between bacterioferritin (Bfr) and this NIFU-like [2Fe-2S] protein, which is dubbed Bfd. An open reading frame encoding a homologous Bfd is located near a Bfr gene in at least one other bacterium. Bfd may, therefore, constitute a general redox and/or regulatory component participating in the iron storage or mobilization functions of Bfr.

Helix-loop-helix proteins LYL1 and E2a form heterodimeric complexes with distinctive DNA-binding properties in hematolymphoid cells

LYL1 is a basic helix-loop-helix (HLH) protein that was originally discovered because of its translocation into the beta T-cell receptor locus in an acute lymphoblastic leukemia. LYL1 is expressed in many hematolymphoid cells, with the notable exceptions of thymocytes and T cells. Using the yeast two-hybrid system to screen a cDNA library constructed from B cells, we identified the E-box-binding proteins E12 and E47 as potential lymphoid dimerization partners for LYL1. The interaction of LYL1 with E2a proteins was further characterized in vitro and shown to require the HLH motifs of both proteins. Immunoprecipitation analyses showed that in T-ALL and other cell lines, endogenous LYL1 exists in a complex with E2a proteins. A preferred DNA-binding sequence, 5'-AACAGATG(T/g)T-3', for the LYL1-E2a heterodimer was determined by PCR-assisted site selection. Endogenous protein complexes containing both LYL1 and E2a bound this sequence in various LYL1-expressing cell lines and could distinguish between the LYL1 consensus and muE2 sites. These data demonstrate that E2a proteins serve as dimerization partners for the basic HLH protein LYL1 to form complexes with distinctive DNA-binding properties and support the hypothesis that the leukemic properties of the LYL1 and TAL subfamily of HLH proteins could be mediated by recognition of a common set of target genes as heterodimeric complexes with class I HLH proteins.

C-Fos proteins are not involved in the activation of preproenkephalin gene expression in rat brain by peripheral electric stimulation (electroacupuncture)

The present work was designed to study the role of the oncogene product c-Fos in activating the transcription of preproenkephalin (PPE) gene following a kind of peripheral electric stimulation known as electroacupuncture (EA) stimulation. The temporal patterns of rat brain c-fos and PPE mRNA expression were evaluated using the method of Northern blotting, showing that c-fos mRNA expression, which peaked at 2 h after the termination of EA, was always ahead of the PPE mRNA expression which began at 4 h and peaked at 48 h after EA. The methods of immunocytochemistry (ICC) and in situ hybridization (ISH) techniques were combined to identify the co-existence of c-Fos protein and PPE mRNA at the cellular level. The results showed that only a small percentage of PPE mRNA-containing neurons depicts Fos-like immunoreactive nuclei. These findings suggest that c-Fos protein may not be involved in the activation of brain PPE gene transcription induced by peripheral electric stimulation.

Multiplex genotype determination at a large number of gene loci

To facilitate large-scale genotype analysis, an efficient PCR-based multiplex approach has been developed. For simultaneously amplifying the target sequences at a large number of genetic loci, locus-specific primers containing 5' universal tails are used. Attaching the universal tails to the target sequences in the initial PCR steps allows replacement of all specific primers with a pair of primers identical to the universal tails and converts the multiplex amplification into "uniplex." Simultaneous amplification of 26 genetic loci with this approach is described. The multiplex amplification can be coupled with genotype determination. By incorporating a single-base mismatch between a primer and the template into the target sequences, a polymorphic site can be converted into a desirable restriction fragment length polymorphism when it is necessary. In this way, the allelic PCR products for the polymorphic loci can be discriminated by gel electrophoresis after restriction enzyme digestion. In this study, 32 loci were typed in such a multiplex way.

Identification of a glucocorticoid repressor domain in the rat beta 1-adrenergic receptor gene

The expression of the gene encoding the rat beta 1-adrenergic receptor is suppressed by glucocorticoids (Kiely et al., 1994). Within the 3.2-kb 5'-flanking region of the promoter, two potential glucocorticoid response elements (GREs) at -950 and -2791 relative to the translational ATG were identified. Characterization of the glucocorticoid-responsive sequences in the 5'-flanking region of the beta 1-adrenergic receptor gene was explored in rat C6 glioma cells and human HepG2 hepatoma cells using transient expression of beta 1-adrenergic receptor-luciferase fusion genes. The ability of glucocorticoids to suppress luciferase expression was not altered when the most 5'-localized GRE was deleted. Deleting the potential GRE at -950, in contrast, abolished glucocorticoid-induced suppression of the beta 1-adrenergic receptor-luciferase gene transcription. A 25-bp element containing the GRE sequence between nucleotides -950 and -926 confers glucocorticoid-dependent inhibition of transcription to a neutral promoter. Gel mobility shift assays with the alpha-subunit of the human glucocorticoid receptor (hGR alpha) expressed in reticulocyte lysates demonstrated specific binding to the 25-bp sequence harboring the putative GRE. We report an inhibitory GRE in the promoter of the rat beta 1-adrenergic receptor gene that is conserved among the rat, human, and mouse genes.

Pentoxifylline ameliorates pulmonary damage caused by Streptococcus pneumoniae infection in mouse

Streptococcus pneumoniae stimulated mouse peritoneal macrophage to release tumor necrosis factor-alpha (TNF alpha) in vitro. When penicillin was added into the medium with bacteria, TNF alpha release was accelerated. Pentoxifylline (PTX), a phosphodiesterase inhibitor, significantly attenuated TNF alpha release caused either by Streptococcus pneumoniae or by its lysates. In this experiment, 150 Kunming mice were infected with Streptococcus pneumoniae through inspiration. Dynamic changes of TNF alpha concentration in serum and bronchoalveolar lavage fluid were determined, and pulmonary pathological changes were also observed. It was found that PTX significantly attenuated TNF alpha activity in serum and bronchoalveolar lavage fluid, and inhibited white blood cell chemotaxis, emigration and infiltration. In conclusion, Streptococcus pneumoniae infection stimulates the release of TNF alpha which is probably the major mediater that causes tissue damage during Streptococcus pneumoniae infection. The mechanism is probably that Streptococcus pneumoniae and its lysates activate TNF alpha gene transcription. As penicillin accelerates TNF alpha release, treatment with penicillin alone may aggravate the tissue damage. Combined treatment with PTX may be more reasonable.

The role of the cell cycle and cytokinesis in regulating neuroblast sublineage gene expression in the Drosophila CNS

The precise temporal control of gene expression is critical for specifying neuronal identity in the Drosophila central nervous system (CNS). A particularly interesting class of genes are those expressed at stereotyped times during the cell lineage of identified neural precursors (neuroblasts): these are termed ‘sublineage’ genes. Although sublineage gene function is vital for CNS development, the temporal regulation of this class of genes has not been studied. Here we show that four genes (ming, even-skipped, unplugged and achaete) are expressed in specific neuroblast sublineages. We show that these neuroblasts can be identified in embryos lacking both neuroblast cytokinesis and cell cycle progression (string mutants) and in embryos lacking only neuroblast cytokinesis (pebble mutants). We find that the unplugged and achaete genes are expressed normally in string and pebble mutant embryos, indicating that temporal control is independent of neuroblast cytokinesis or counting cell cycles. In contrast, neuroblasts require cytokinesis to activate sublineage ming expression, while a single, identified neuroblast requires cell cycle progression to activate even-skipped expression. These results suggest that neuroblasts have an intrinsic gene regulatory hierarchy controlling unplugged and achaete expression, but that cell cycle- or cytokinesis-dependent mechanisms are required for ming and eve CNS expression.

The antiproteinuric action of angiotensin-converting enzyme is dependent on kinin

Converting enzyme inhibitors (CEI) reduce proteinuria in nephrotic humans and animals, but the mediator(s) of this effect has not been identified definitively. To determine whether enhanced kinin activity contributes to the antiproteinuric action of CEI, rats with passive Heymann nephritis were treated with the B2 kinin receptor antagonist HOE 140, 300 micrograms/kg per day, for 3 days and then the CEI enalapril (ENAL), 35 mg/kg per day, was given for another 4 days while HOE 140 was continued (HOE/ENAL). Additional groups of nephrotic rats were untreated (CON), received HOE 140 only (HOE), or received ENAL only. ENAL alone produced a > 60% decrease in albuminuria after 4 days, whereas HOE 140 alone had no effect on albuminuria. In HOE/ENAL, pretreatment with HOE 140 prevented the decrease in albuminuria observed in ENAL. GFR increased significantly over time in all groups but was not different among the groups on any day. The clearance of albumin decreased significantly in ENAL (P < 0.001) and was significantly lower than in CON, HOE, or HOE/ENAL on Day 10. The fractional clearance of albumin decreased in all groups as a result of the increase in GFR but was significantly lower in ENAL compared with the other three groups at Day 10 and was not different between CON, HOE, and HOE/ENAL. Plasma renin activity and concentration were increased significantly in both ENAL and HOE/ENAL, indicating that converting enzyme was effectively inhibited in both groups. It was concluded that enhanced kinin activity contributes to the antiproteinuric action of CEI in this model of nephrotic syndrome.

[The use of measuring serum soluble IL-2 receptor levels in cyclosporine-A treated lupus nephritis]

Twenty-one patients with Lupus Nephritis (LN) were treated with cyclosporine-A (CsA) for three months. Serum soluble interleukin-2 receptors (SIL-2R) were measured before and after treatment and correlated prospectively with serologic findings of LN activity. The patients had significantly higher IL-2R level before treatment (during LN flare) than after treatment (disease remission). A significant positive correlation was present between serum SIL-2R and proteinuria, and ANA as well, whereas the SIL-2R levels in LN patients were inversely correlated with serum levels of C3 and CH50. These observations suggest that serum SIL-2R level is an useful marker of disease activity in LN and may serve as a helpful adjunct in the management of this disorder.

[Correlation studies on the alterations of multiple tumor suppressor genes in human esophageal cancer and in human and monkey esophageal epithelial cells treated with N-methyl-N-benzyl nitrosamine]

The correlation between the mutation spectra of tumor suppressor genes Rb, p53, APC and MCC in human esophageal cancer (EC) and in human and monkey esophageal epithelium treated with N-Methyl-N-Benzyl nitrosamine (NMBzA) was studied using PCR amplification and direct sequencing methods. The results showed that in 40.9% (9/22) of the specimen examined, the mutation spectrum of p53 in primary EC was similar to that in the esophageal epithelium of human fetus (in vitro) and monkey (in vivo) treated with NMBzA. The same mutational spectra of tumor suppressor genes Rb, APC, MCC in esophageal epithelium cells of human and monkey treated with NMBzA were also found in some human primary EC. The correlation observed in the mutation spectra of multiple tumor suppressor genes between human primary EC and the esophageal epithelia of human and monkey origin treated with NMBzA wouldsuggest that NMBzA may be the esophageal etiological agent for human esophageal cancer in China.

[Expression and localization of immediate early genes and preproenkephalin gene in central nervous system following electroacupuncture stimulation]

Using the techniques of immunohistochemistry, Northern blotting and in situ hybridization, we have found that electroacupuncture (2/15Hz) accelerated the expression of mRNA and protein synthesis of immediate early genes c-fos, c-jun as well as proenkephalin gene in rat central nervous system (CNS). Northern hybridization revealed that EA stimulation induced c-fos gene expression within 1-2 h, followed by PENK gene expression which peaked at 48h. Morphological study demonstrated that the sites of c-fos, c-jun and PENK mRNA expression and protein synthesis coincide with each other in the CNS. The results suggest that Fos/Jun may function as the transcription regulator of PENK gene.

[Multiple tumor suppressor genes in esophageal carcinoma induced in human fetus esophageal epithelium by NMBzA]

Results of epidemiological studies have shown that nitrosamine-induced carcinogensis is involved in esophageal cancer in China. In order to demonstrate the mechanism at molecular level, Multiple tumor suppressor genes Rb, p53, APC and MCC in human fetus esophageal epithelium treated with NMBzA (in vitro) for 24 hours or three weeks and esophageal carcinoma induced by NMBzA were analyzed with PCR amplification and direct sequencing. In PCR amplification analysis. Rb, p53, APC and MCC deletions in esophageal carcinoma of human fetus induced by NMBzA were found, but no deletions of these genes was demonstrated in NMBzA-treated human fetal esophageal epithelium. PCR direct sequencing analysis revealed mutation of p53, Rb and MCC genes in human fetal esophageal epithelium treated with NMBzA for three weeks. The results first confirmed (in vitro) that nitrosamine can cause mutations and deletions of multiple tumor suppressor genes in human esophageal epithelium. The mutations of tumor suppressor genes in nitrosamine-induced esophageal carcinoma may occur in the early stage, while deletions in late stage of carcinogenesis.

Novel proteins of the phosphotransferase system encoded within the rpoN operon of Escherichia coli. Enzyme IIANtr affects growth on organic nitrogen and the conditional lethality of an erats mutant

Two rpoN-linked delta Tn10-kan insertions suppress the conditionally lethal erats allele. One truncates rpoN while the second disrupts another gene (ptsN) in the rpoN operon and does not affect classical nitrogen regulation. Neither alter expression of era indicating that suppression is post-translational. Plasmid clones of ptsN prevent suppression by either disruption mutation indicating that this gene is important for lethality caused by erats. rpoN and six neighboring genes were sequenced and compared with sequences in the database. Two of these genes encode proteins homologous to Enzyme IIAFru and HPr of the phosphoenolpyruvate:sugar phosphotransferase system. We designate these proteins IIANtr (ptsN) and NPr (npr). Purified IIANtr and NPr exchange phosphate appropriately with Enzyme I, HPr, and Enzyme IIA proteins of the phosphoenolpyruvate: sugar phosphotransferase system. Several sugars and tricarboxylic acid cycle intermediates inhibited growth of the ptsN disruption mutant on medium containing an amino acid or nucleoside base as a combined source of nitrogen, carbon, and energy. This growth inhibition was relieved by supplying the ptsN gene or ammonium salts but was not aleviated by altering levels of exogenously supplied cAMP. These results support our previous proposal of a novel mechanism linking carbon and nitrogen assimilation and relates IIANtr to the unknown process regulated by the essential GTPase Era.

Culture of bladder epithelium from cystoscopic biopsies of patients with interstitial cystitis

Interstitial cystitis is a chronic disease of unknown etiology characterized by bladder pain and urinary frequency and urgency. The epithelium may be critical in its pathogenesis; the hallmarks of the disease are visible epithelial defects (Hunner's ulcers and epithelial ruptures). Areas denuded of epithelium are commonly seen, and defects in epithelial permeability are characteristic. We report here the culture and characterization of epithelial cells from cystoscopic bladder biopsies obtained from 7 female patients with interstitial cystitis. Within 4 to 14 days cellular outgrowths appeared from explants incubated in cell medium. Monolayers reached confluence after 6 weeks. Cells of the monolayer were cytokeratin-positive and smooth muscle actin-negative, confirming their epithelial origin. They exhibited epithelial cell ultrastructure including intermediate filaments and junctional complexes. Vesicles bounded by a trilaminar plasma membrane and lateral interdigitations were also present. This is the first report of the culture of bladder epithelium from interstitial cystitis patients. Epithelial cells may be targets for initiating agents and inflammatory effects of interstitial cystitis and should be useful for studies of the pathogenesis of this disease.

[Analysis of 100 cases of precancerous laryngeal lesions]

Hundred cases of precancerous laryngeal lesions were analysed on the basis of clinical pathology. The results showed that there was close relationship between the precancerous laryngeal lesions and voice abuse and long-term heavy smoking. The pathology showed epithelial hyperplasis and mild to severe atypical hyperplasia (heterotype). Scanning electronmicroscopy revealed that the more severe the degree of the epithelial heterotype, the more pleomorphic the shape of cell morphology, margin. Twenty cases had malignant changes later, and the rate of malignant change was high in those with atypical hyperplasia. Some lesions which were taken for polyps clinically and pathologycally could also have malignant changes, so more attention should be paid to these lesions during clinical management.

Identification and characterization of phosphoenolpyruvate:fructose phosphotransferase systems in three Streptomyces species

Streptomyces lividans, S. coelicolor and S. griseofuscus were examined for the presence of the enzymes of the phosphoenolpyruvate:sugar phosphotransferase system (PTS). All three species were shown to possess Enzyme I, HPr and fructose-specific Enzyme II (IIFru) activities. In S. lividans and S. coelicolor, all three PTS enzymes were fructose-inducible, but in S. griseofuscus the system was expressed constitutively. These organisms apparently lack the HPr(Ser) kinase and HPr(Ser-P) phosphatase that characterize low-GC Gram-positive bacteria.

[Streptococcus pneumoniae-induced pulmonary consolidation prevented with tumor necrosis factor alpha monoclonal antibody in mouse]

Streptococcus pneumoniae stimulate mouse peritoneal macrophages to release tumor necrosis factor alpha (TNF alpha) in vitro. When penicillin was added to lysate bacterium, TNF alpha release was accelerated. 150 Kunming mice were infected with streptococcus pnumoniae through inspiration. Dynamic changes of TNF alpha concentration in serum and bronchoalveolar lavage fluid were detected; pulmonary pathological changes were also observed. It was found that TNF alpha monoclonal antibody significantly attenuates TNF alpha activity in serum and bronchoalveolar lavage fluid, white blood cell chemotaxis, emigation, and infiltration were inhibited. We conclude that streptococcus pneumoniae infection stimulates TNF alpha release, and TNF alpha is probably the major mediator that causes tissue damage during streptococcus pneumoniae infection. As penicillin accelerates TNFa release, single therapy of penicillin may worse tissue damage.