[Clinical study on nosocomial infection in patients with burns]

OBJECTIVE

To study clinical characters and related factors of nosocomial infection in patients with burns.

METHODS

To study 782 cases of burns as a group hospitalized in our department for more than 48 h, from January, 1993 to December, 1996. Prospective and retrospective investigation of infection locations, infection rates, pathogen and drug sensibility was carried out.

RESULTS

The infection most often found in blood and wound, less often in respiratory system. Nosocomial infection rates in patients with burns were closely related to the severe degree, diagnosis and therapy of these patients and hospital surroundings. Infection bacteria species: Gram-positive bacterium accounted for 43.82%, and mainly were staphylococcus aureus and anaerobic peptococcus. Gram-negative bacterium accounted for 52.81%, of which pseudomonas aeruginosa and nitrate-negative bacillus constituted the majority.

CONCLUSION

According to these characters and related factors of nosocomial infection in patients with burns, effective measures of preventing and controlling infection should be taken, so that the incidence of nosocomial infection in these patients will drop.

[Treatment of diseased middle turbinate in endoscopic sinus surgery]

OBJECTIVE

To study the clinical significance of reservation of the middle turbinate in functional endoscopic sinus surgery (FESS) for sinusitis and/or nasal polyps.

METHOD

According to anatomic criteria of the middle turbinate surgery in adult, 32 cases who had sinusitis and/or nasal polyps were treated and followed up. The recovery of middle turbinate contour, postoperative ethmoid cavity and the rate of patency of the maxillary sinus ostium were observed postoperatively.

RESULT

1. After 6 months, the form of middle turbinate returned to normal in 24 cases (75%), adhesions occurred in 8 cases (25%), including the closure of ethmoid sinus cavity in 2 cases. 2. The patency of maxillary sinuses ostium maintained well in 25 cases (78.1%), stenosed in 6 cases (18.8%) and closed in 1 case (3.1%). The diseased middle turbinate can recover to normal contour in most cases, often plastics in FESS.

CONCLUSION

Reservation of middle turbinate plays an important role in promoting the clinical cure rate.

PFM1 (PRDM4), a new member of the PR-domain family, maps to a tumor suppressor locus on human chromosome 12q23-q24.1

The PR domain, first noted as the PRDI-BF1 (HGMW-approved symbol PRDM1) and RIZ (HGMW-approved symbol PRDM2) homologous region, defines a small family of transcription factors involved in cell differentiation and tumorigenesis. The shared role of this family in human cancer raises considerable interest in identifying novel members of this family as candidate cancer genes. This paper describes a new human PR family member, designated PFM1 (HGMW-approved symbol PRDM4). A full-length PFM1 cDNA of 3902 nucleotides has been isolated based on its homology to the PR domain. It encodes an open reading frame of 796 amino acids and contains a PR domain in the middle region and six zinc finger motifs at the carboxyl-terminus. Several PFM1 mRNA species of different lengths were detected by Northern blot analysis, one species of which lacked the amino-terminal region of PFM1 and part of the PR domain. The major PFM1 mRNA species of approximately 4.6 kb was widely expressed but more abundant in ovary, testis, pancreas, brain, heart, and prostate. PFM1 mRNA levels were highly elevated in PC12 cells treated with NGF, suggesting a role for PFM1 in the NGF signal transduction pathway. STS marker and radiation hybrid analyses mapped PFM1 to human chromosome 12q23-q24.1, a region thought to harbor tumor suppressor genes for ovarian, gastric, and pancreatic cancers. These results suggest a role for PFM1 in cell differentiation and tumor suppression, remarkably consistent with the known functions of the PR-domain family.

Telomerase activation in nasopharyngeal carcinomas

Nasopharyngeal carcinomas (NPC) are common in Hong Kong and southern China but rare in Western countries. Telomerase activation is common in human cancers but has not been reported previously in NPC. Telomerase activation in NPC was determined using the sensitive TRAP (telomerase rapid amplification protocol) assay in 45 nasopharyngeal biopsies (36 NPC, nine normal nasopharyngeal mucosae) in four xenografted NPC tumours established in nude mice and in five in vitro NPC cell lines. Telomerase activation is common in NPC and can be detected at high frequencies (85% in primary tumours and 100% in recurrent tumours). The frequency of telomerase activation was lowest in NPC biopsies without lymph node involvement (60%) compared with those with positive lymph node involvement (100%), and the difference is statistically significant (P < 0.05; Fisher exact test). All the xenografted NPC tumours and in vitro NPC cell lines were strongly positive for telomerase activity. Our results suggest that telomerase activation is common in NPC and it may be useful as a diagnostic marker in the detection of tumour cells in nasopharyngeal biopsies. The high frequency of telomerase activation in stage I NPC (80% positive) suggests that it is an early event in tumour progression.

Novel phosphorylated forms of E2F-1 transcription factor bind to the retinoblastoma protein in cells overexpressing an E2F-1 cDNA

In cells overexpressing an exogenous cDNA encoding the E2F-1 transcription factor, as many as eight closely-migrating protein bands were detected after denaturing protein gel electrophoresis and immunoblotting with an E2F-1-specific antibody. Control cells, not overexpressing an E2F-1 cDNA, contained only four E2F-1 specific bands. Pretreatment of protein extracts, from both control and E2F-1 overexpressing cells, with lambda-phosphatase eliminated all E2F-1-specific bands except the single band migrating most rapidly on the gels. These data demonstrated that the multiple protein bands were differentially-phosphorylated forms of E2F-1 protein and showed that novel, more highly phosphorylated E2F-1 forms were present in cells overexpressing the E2F-1 protein. In addition, immunoprecipitation of the retinoblastoma (pRb) protein from cells overexpressing the E2F-1 cDNA showed that the novel, highly phosphorylated E2F-1 forms were preferentially coimmunoprecipitated, indicating that pRb bound preferentially to these E2F-1 forms.

[Mechanism of intracellular calcium homeostasis in heat-exposed cardiomyocytes of rats]

The activity of Ca(2+)-ATPase and calcium content were measured in sarcoplasmic reticulum (SR) and mitochrondria of myocardium from 40 adult female Wistar rats after exposure to 37 degrees C, 39 degrees C, 41 degrees C and 43 degrees C for 40 min respectively in vitro. The 45Ca uptake, intracellular free Ca2+ concentration ([Ca2+]i) and the relatively active calmodulin content were also observed in cultured cardiomyocytes from 120 neonatal Wistar rats under the same condition of heat exposure. The results showed that (1) the activity of Ca(2+)-ATPase of SR and mitochrondria of myocardium decreased after heat exposure, (2) the calcium content of SR and mitochrondria also showed a tendency of decrease with increase of exposure temperature, (3) the 45Ca uptake and mean [Ca2+]i increased, whereas the calmodulin content decreased. It is suggested that disturbances of intracellular calcium homeostasis may be responsible for cardiac functional disorder after heat exposure.

Platelet-derived growth factor B-chain comprises the major part of enhanced released mitogen from aortic endothelial cells of stroke-prone spontaneously hypertensive rats

1. The present study was conducted to analyse the release and production of mitogen in cultured aortic endothelial cells of stroke-prone spontaneously hypertensive rats (SHRSP), for the further understanding of the role of arterial endothelial cells in the genesis of vascular lesions in hypertension. 2. The cultured aortic endothelial cells derived from SHRSP increased released mitogens were compared with those from control Wistar-Kyoto rats (WKY) with respect to cultured vascular medial smooth muscle cells and fibroblasts. 3. Biochemical analyses determined that the major part of mitogen released from aortic endothelial cells of both SHRSP and controls was the platelet-derived growth factor B-chain. 4. Further northern analyses revealed that the transcripts of PDGF B-chain were constitutively accumulated three- to four-fold in quiescent aortic endothelial cells from SHRSP, compared with those from WKY through passages 2 to 5. 5. However, the half-lives of the transcripts after actinomycin D treatment were 1.12 h (s.d. = 0.14, n = 4) and 1.28 h (s.d. = 0.08, n = 3), in SHRSP and in WKY, respectively, showing no significant difference. 6. These suggest that the increased accumulated transcripts of PDGF B-chain in SHRSP are due to an enhanced transcriptional rate. These enhanced release and production of PDGF-B chain in arterial endothelial cells, which may be induced under chronic hypertensive conditions, is suggested to contribute to the genesis of vascular lesion in hypertension, through the stimulation of vascular smooth muscle cell proliferation and hypertrophy.

Overexpression of the E2F-1 transcription factor gene mediates cell transformation

The E2F transcription factor can regulate expression of numerous cellular genes controlling proliferation, including proto-oncogenes and genes regulating cell cycle progression. Therefore, genes comprising the E2F gene family could potentially contribute to carcinogenesis. To test the potential of E2F to act as a transforming gene, a cDNA encoding E2F-1 was constitutively overexpressed in established rodent cells using a retroviral vector. Overexpressed E2F-1 was functional, as shown by stimulation of a transfected adenovirus E2 promoter driving a chloramphenicol acetyltransferase reporter gene in E2F-1 overexpressing cells. This stimulation was dependent on functional E2F binding sites in the promoter. Examination of phenotype showed that E2F-1 overexpression mediated cell transformation as measured by the ability of cells to form colonies in soft agar medium. In addition, overexpressed E2F-1 shortened the duration of the G1 cell cycle phase in proliferating cells, a property characteristic of other transforming genes. These data provide direct evidence that E2F-1 can act as a transforming gene and a critical regulator of cell cycle progression and suggest the possibility of E2F involvement in carcinogenesis.

[Effects of vocalization and respiration and fiber connections on hyperstriatum ventrale pars caudale in Fringilla montifringilla]

In urethane-anesthetized Fringilla montifringilla, effects of electrically stimulating the hyperstriatum ventrale pars caudale (HVc) on vocalization and respiration were observed. Central connections of HVc were investigated by means of injecting CB-HRP into HVc. The results were as follows: (1) Electrical stimulation of HVc caused vocal response. (2) Long train electrical pulses stimulation of HVc elicited significant respiratory facilitating effects, that is, increase of respiratory rate and depth. (3) Short train stimulation administered in HVc during inspiratory phase terminated switching-off of inspiration, and during expiratory phases produced the prolongation of expiratory phase so to coordinate vocalization and then increasing the respiratory rate and depth. (4) CB-HRP traces revealed that HVc projected to robust nucleus of the archistriatum, and atea X of lobus parolfactorius. HVc received projections from medial nucleus magnocellularis of the anterior neostriatum, nucleus interfacialis of midneostriatum, telencephalic auditory nucleus-field L, nucleus uvaeformis of the thalamus, and locus ceruleus of the pons. These results showed that, besides vocal control, HVc may be involved in neural regulations of respiratory facilitation, the effect on respiration seeming specific. It is suggested that HVc may play an important role in coordinating singing and respiration.

Immunoglobulin A antibodies directed against Campylobacter jejuni flagellin present in breast-milk

We studied the relationship between IgA anti-campylobacter flagellin antibodies in breast milk samples and protection of breastfed infants living in a rural Mexican village from campylobacter infection. There were fewer episodes of campylobacter infection (symptomatic and asymptomatic combined) in infants breastfed with milk containing specific anti-flagellin antibodies (1.2/child/year, 95% CI 0.6-1.8) versus non-breastfed children (3.3/child/year, 95% CI 1.8-4.8; P < 0.01). Infants breastfed with milk that was anti-flagellin antibody negative by ELISA also had fewer episodes of infection compared with non-breastfed children, but the difference did not reach statistical significance (1.8/child/year, 95% CI 0.7-3.0 versus 3.3/child/year, 95% CI 1.8-4.8, P > 0.05). Breastfeeding has a protective effect against campylobacter infection and is associated with the presence of specific antibodies directed against campylobacter flagellin.

alpha-Tocopherol protects against radical-induced injury in cultured neurons

The effect of alpha-tocopherol on neurons in protecting against radical-induced injuries caused by cumene hydroperoxide was assessed using a culture system. Structural and biochemical deteriorations in both clonal neuroblastoma cells and primary cultured neurons were induced by cumene hydroperoxide. These deteriorative changes were prevented prevented by pretreatment of alpha-tocopherol. Since simultaneous supplementation of alpha-tocopherol and cumene hydroperoxide had limited protective effects, prophylactic administration of alpha-tocopherol for risk patients with brain diseases concerned with damages induced by free radical is recommended to hamper the progression of neuronal impairment after attacks.

Role of Campylobacter jejuni flagella as colonization factors for three-day-old chicks: analysis with flagellar mutants

Campylobacter jejuni, an important cause of human gastrointestinal infection, is a major food-borne pathogen in the United States and worldwide. Since poultry becomes colonized and/or contaminated during the early stages of production and is a major food-borne source for this organism, we studied the role of C. jejuni flagella on the ability of the bacterium to colonize the chicken gastrointestinal tract. Three-day-old chicks were orally challenged with a motile wild-type strain of C. jejuni IN9 or with flagellar mutants created from IN9 by disrupting the flagellin genes with a kanamycin resistance cassette by using shuttle mutagenesis (A. Labigne-Roussel, P. Courcoux, and L. Tompkins, J. Bacteriol. 170:1704-1708, 1988). One mutant, IN9-N3, lacked flagella and was nonmotile. The other, IN9-N7, produced a truncated flagellum and was partially motile. Three-day-old chicks were orally challenged with different doses of the wild-type strain and the two mutants. At challenge doses ranging from 3.0 x 10(4) to 6.6 x 10(8) CFU per chick, only the fully motile, wild-type strain colonized the chick ceca. Our results show that intact and motile flagella are important colonization factors for C. jejuni in chicks.

Regulation of central muscarinic receptors after cholinesterase inhibition: effect of clonidine

In rats, the injection of soman (70 micrograms/kg, SC) resulted in a 90% inhibition of the cholinesterase (ChE) activities in three brain regions. The density (Bmax) for muscarinic acetylcholine receptors (mAChRs) following a single injection of soman was significantly reduced at 2 h after injection in the cortex and hindbrain. Bmax values, however, returned to baseline within 24 h. Subacute (repeated injection every 15 min) treatment with a sublethal dose of soman over 2 h also decreased the density of mAChRs. In both cases the density of mAChRs was reduced by about 15% for the cortex and 17% for the hindbrain (the midbrain was also reduced by 18% for subacute injections). Chronic administration (once daily for 7 days) of soman (20 micrograms/kg, SC) produced maximal inhibition of ChE activity but did not significantly downregulate mAChRs. Clonidine pretreatment reversed the soman-induced mAChR downregulation in cortex and hindbrain produced by acute soman administration. Thus, marked reduction in the levels of brain ChE is not the only factor involved in the production of mAChR downregulation to cholinesterase inhibitors.

[Transurethral microwave radiation for bladder neoplasm]

42 patients with bladder neoplasm were treated effectively by transurethral microwave radiation in our hospital from March, 1990 to October 1991. No serious complication was found after this treatment and its long-term result was better than others. The principle of this method is to use the biological availability of microwave to heat the neoplasm and to evoke the cellular immunity system to kill tumor cells, because tumor cells is more likely to be killed than normal tissue cell by heat. Generally, tumor cells would be killed when the temperature is higher than 42 degrees C. The protection against microwave during the treatment was also discussed.

Central anticholinergic hypersensitivity in aging

Although neurochemical reductions in cholinergic systems have been found to occur during aging, such changes do not necessarily translate to functional deficits. The cognitive deficits of normal aging have been attributed in part to hypocholinergic function, but anticholinergic hypersensitivity in the elderly has not been systematically documented. To test the cholinergic hypothesis of aging, we investigated the effects of scopolamine on memory and attention in healthy young and elderly subjects. Treatments included intramuscular glycopyrrolate (0.0044 mg/kg) and scopolamine (0.002, 0.004, and 0.007 mg/kg) in a randomized double-blind design. The test battery included the Selective Reminding Task (SRT), Digit Span, Paired Associates Learning (PAL), Symbol Digit Modalities Test (SDMT), and the Continuous Performance Task. Elderly controls were more impaired at lower scopolamine doses than were the young on SRT, PAL, and SDMT. These results demonstrate anticholinergic hypersensitivity and are consistent with decremental changes in cholinergic status during normal aging.

Local immune responses to the Campylobacter flagellin in acute Campylobacter gastrointestinal infection

Intestinal immunoglobulin A (IgA) anti-campylobacter flagellin antibodies were measured by an enzyme-linked immunosorbent assay in patients with and without campylobacter infections. The level of fecal IgA antiflagellin antibodies was significantly higher in patients than in controls, but only 12 of 29 patients (41.4%) with a campylobacter infection had detectable IgA antibodies against flagellin (optical density, greater than or equal to 0.100). Further testing of fecal IgA antibodies from 10 patients with homologous and heterologous purified flagellins showed strain specificity in 1 patient. Cross-reactivity of fecal IgA antibodies with heterologous flagellins did not correlate with the Lior serotype of the isolate.

Two Drosophila receptor-like tyrosine phosphatase genes are expressed in a subset of developing axons and pioneer neurons in the embryonic CNS

Two Drosophila receptor-like tyrosine phosphatase genes, DPTP99A and DPTP10D, were characterized. Protein products of these genes show distinct expression patterns specific to subsets of developing CNS axons. DPTP99A expression coincides with the onset of axonogenesis and is expressed in several pioneer neurons, including aCC and RP2, which pioneer the intersegmental nerve; its proteins are transiently expressed in the intersegmental and segmental nerves, arguing for a role in the establishment of these nerves. Both genes produce complex sets of transcripts, owing to the alternative utilization of exons and polyadenylation sites. Each gene produces alternative protein forms, which differ in their C-terminal tails. The deduced proteins possess extracellular FN-III repeats and intracellular PTPase domain(s). We discuss the implications of these results and the role of protein tyrosine dephosphorylation in axon outgrowth and guidance.

Repertoire diversity of antibody response to bacterial antigens in aged mice. II. Phosphorylcholine-antibody in young and aged mice differ in both VH/VL gene repertoire and in specificity

Aging of mice is accompanied by both quantitative and qualitative changes in antibody responses to phosphorylcholine (PC), an immunodominant epitope of Streptococcus pneumoniae R36a strain (Pn). In order to study these changes at the molecular level, we generated PC-specific hybridomas from young (3 to 4 mo) and aged (20 to 24 mo) mice of different strains after primary immunization with S. pneumoniae R36a strain. These mAb were tested for Ig VH and VL gene family utilization, idiotopic repertoire, and cross-reactivity with unrelated Ag. Hybridomas from young mice (BALB/c, C57BL/6, and D1.LP) uniformly expressed the VH-S107 and V kappa-22 genes as well as most idiotopes of the T15 family, which were identified with different anti-T15 mAb. In contrast, the PC-reactive mAb from aged mice were quite heterogeneous: only 2 out of 13 utilized VHS107, 1 of 13 used VH7183, and 3 of 13 used VHJ558 gene family. Moreover, none of these mAb used L chain encoded by V kappa 22(0/13), but surprisingly they frequently expressed some of the T15 idiotope. In addition, the PC-binding mAb from aged mice showed broad cross-reactivity with various mouse and foreign proteins, whereas the mAb from young mice did not. These results demonstrate the genetic shift in antibody response of aging mice to PC, which is accompanied by a change in the antibody specificity. Interestingly, the qualitative repertoire change appears to be unrelated to the magnitude of antibody response, for the aged BALB/c mice maintain a very high reactivity to PC.

Repertoire diversity of antibody response to bacterial antigens in aged mice. II. Phosphorylcholine-antibody in young and aged mice differ in both VH/VL gene repertoire and in specificity

Aging of mice is accompanied by both quantitative and qualitative changes in antibody responses to phosphorylcholine (PC), an immunodominant epitope of Streptococcus pneumoniae R36a strain (Pn). In order to study these changes at the molecular level, we generated PC-specific hybridomas from young (3 to 4 mo) and aged (20 to 24 mo) mice of different strains after primary immunization with S. pneumoniae R36a strain. These mAb were tested for Ig VH and VL gene family utilization, idiotopic repertoire, and cross-reactivity with unrelated Ag. Hybridomas from young mice (BALB/c, C57BL/6, and D1.LP) uniformly expressed the VH-S107 and V kappa-22 genes as well as most idiotopes of the T15 family, which were identified with different anti-T15 mAb. In contrast, the PC-reactive mAb from aged mice were quite heterogeneous: only 2 out of 13 utilized VHS107, 1 of 13 used VH7183, and 3 of 13 used VHJ558 gene family. Moreover, none of these mAb used L chain encoded by V kappa 22(0/13), but surprisingly they frequently expressed some of the T15 idiotope. In addition, the PC-binding mAb from aged mice showed broad cross-reactivity with various mouse and foreign proteins, whereas the mAb from young mice did not. These results demonstrate the genetic shift in antibody response of aging mice to PC, which is accompanied by a change in the antibody specificity. Interestingly, the qualitative repertoire change appears to be unrelated to the magnitude of antibody response, for the aged BALB/c mice maintain a very high reactivity to PC.

Enhancement of interleukin 2 production in human and Gibbon T cells after in vitro treatment with lithium

The effect of trace elements lithium, selenium, and zinc on interleukin 2 (IL-2) production by peripheral blood mononuclear cells (PBMC), MLA144, and Jurkat cell lines has been studied. Lithium markedly enhanced IL-2 production by MLA144 and PBMC, but not by Jurkat. Selenium could only enhance IL-2 production by MLA144, whereas in none of these three systems was IL-2 production altered by zinc. The enhancing effect of lithium on IL-2 production showed some differences from that of tetradecanoylphorbol acetate (TPA) in the following aspects: (i) TPA could reverse the inhibitory effect of anti-CD2 monoclonal antibody on IL-2 production, whereas lithium could not; and (ii) lithium was unable to synergistically induce IL-2 production with anti-CD3 monoclonal antibody as TPA did. The effect of lithium on IL-2 production was in the early phase of lymphocyte activation. The addition of cholera toxin or theophylline to phytohemagglutinin-stimulated PBMC culture suppressed IL-2 production. However, IL-2 production could be restored by lithium. There was a corresponding increase in cAMP in cholera toxin or theophylline-treated PBMC, which could be reversed by lithium. Therefore, lithium restores IL-2 production via a decrease in cAMP.

Two closely linked Drosophila POU domain genes are expressed in neuroblasts and sensory elements

We have characterized two Drosophila POU genes designated dPOU-19 and dPOU-28. These genes are transcribed as 3.1- and 2.2-kilobase mRNAs, respectively, which accumulate maximally during the first 12 hr of embryogenesis. The mRNAs encode 601- and 475-amino acid deduced proteins; their POU domains are most related to those of the human OCT1 and OCT2. Both genes give similar nervous system expression patterns and map to an indistinguishable site at 33F on the cytological map. Transcription of the genes is first observed in the cellular blastoderm. In the course of embryonic development, expression is observed in the neuroectoderm, with subsets of neuroblasts in the procephalic and germband central nervous system as well as a subset of peripheral nervous system elements. The expression patterns of the two POU genes suggest a possible functional role for these putative transcription factors in neurogenesis and neurospecification.

Effects of scopolamine on visual evoked potentials in aging and dementia

The unusual combination of a normal pattern reversal VEP and a delayed flash VEP has been reported in patients with dementia of Alzheimer's type (DAT). Hyoscine hydrobromide has been reported to produce a similar VEP abnormality in young, healthy subjects. In the present study, we assessed the relative sensitivity of DAT patients and healthy young, middle-aged and elderly subjects to temporary cholinergic blockade. We report VEP latency values following 3 doses of scopolamine and after a peripheral anticholinergic agent. Flash P2 latency was not significantly slower in DAT patients than in the healthy elderly. Scopolamine increased P2 latency in the young controls but did not affect any other group. The pattern reversal P100 was normal in DAT, and a significant increase in latency occurred following scopolamine administration in both the control and patient groups.

Infection of adult Syrian hamsters with flagellar variants of Campylobacter jejuni

Two variants of Campylobacter jejuni IN1 differing in the expression of flagella, IN1 (Fla+ Mot+, wild type) and IN1-NM (Fla- Mot-), were tested for their ability to establish infection in adult hamsters. Animals were challenged intracecally with 2 X 10(9) to 5 X 10(10) CFU and monitored for evidence of infection. None of the challenged animals developed illness. There was a significant difference, however, in the ability of IN1 to infect hamsters (35 of 43) compared with that of IN1-NM (1 of 42) (P less than 0.01). Additionally, eight animals challenged with IN1-NM excreted only the campylobacters of Fla+ phenotype, which were shown to be identical with the parental Fla+ Mot+ type. Both groups of animals developed serum immunoglobulin G antibodies to outer membrane proteins of IN1 as measured by an enzyme-linked immunosorbent assay; however, only animals that excreted Fla+ organisms developed antiflagellin antibodies. In vitro reversibility from Fla+ to Fla- occurred with a frequency of 9.2 X 10(-6) per cell per generation; however, reversion from Fla- to Fla+ could not be detected in vitro. Further characterization of IN1-NM showed that it produced a cytoplasmic 62K flagellin subunit protein, but this protein lacked six epitopes detected in IN1 and also differed in its two-dimensional gel electrophoresis pattern. The results of these studies support the concept that an intact flagellum is necessary for intestinal infection with C. jejuni and that this model may be useful for studying the immune response to C. jejuni.

[Protective effect of the antioxidants selenium, vitamin E, and superoxide dismutase on cultured human endothelial cells (ECs) injured by lipid peroxidation]

Lipid peroxidation was induced in cultured human ECs with cumene hydroxide and the protective effect of antioxidants (selenium, vitamin E and SOD) on endothelial cell injury by lipid peroxidation was investigated. The results showed that after administration of antioxidants (Se, Vit E and SOD), concentration of LPO in ECs induced by cumene hydroperoxide was reduced markedly while 6-Keto-PGF1 alpha content in the medium was increased and cell injury was alleviated. These results indicate that through the protective effect on ECs against lipid peroxidation, antioxidants (Se, Vit E and SOD) might play an important role in retarding the process of atherogenesis.

Human antibody response to Campylobacter jejuni flagellin protein and a synthetic N-terminal flagellin peptide

We measured isotype-specific human antibodies directed against Campylobacter jejuni native flagellin and a synthetic peptide derived from the N-terminal amino acid sequence of the protein by using a microdilution enzyme-linked immunosorbent assay (ELISA). Serum samples from patients with gastrointestinal infection caused by C. jejuni (n = 20) and control samples (number from normal subjects = 20; number from patients with diarrhea other than campylobacter = 20) were tested in this assay. Serum specimens from patients with campylobacter infection showed statistically significant higher isotype-specific antiflagellin antibody titers than control samples did. Detection of immunoglobulin G (IgG) antibodies was less specific (70%) than detection of either IgA or IgM antibodies in infected patients (95%). The sensitivity of testing for any of the isotypes ranged from 64 to 100% in acute-phase serum specimens and 85 to 95% in convalescent-phase serum specimens. An ELISA with an N-terminal synthetic peptide derived from the flagellin protein as antigen was not sensitive (60%) for detecting campylobacter infection but was very specific (97.5%). In conclusion, detection of serum IgA or IgM against C. jejuni flagellin may be a useful marker of infection. Although the N-terminal synthetic peptide was antigenic in a few patients with infection and showed good specificity in the ELISA, additional amino acid sequences with better sensitivity for detecting infection need to be identified.

[Effects of the preparation of xiao long ling on experimental prostatic hyperplasia in mice]

The results of the experiments indicate that the prostatic hyperplasia caused by Testosteroni Propionatis in mice, cotton oil-induced local swollen ears of mice and the proliferation of granuloma produced by subcutaneous implantation of cotton pill in rats are inhibited significantly by the preparation of Xiao Long Ling. Xiao Long Ling depresses the increase of vascular permeability induced by a variety of inflammatory media such as histamine, 5-HT and PGE. Xiao Long Ling is found capable of inhibiting the platelet aggregation induced by ADP as well as depolymerizing the aggregated platelets.

Antinociceptive effect of spinal cholinergic stimulation: interaction with substance P

Activation of central muscarinic receptors results in an antinociceptive response in experimental animals. Employing intrathecal (i.t.) injection and radiant heat applied to a rat's tail as the experimental paradigm, a spinally-mediated antinociceptive response was obtained following injection of cholinergic agonists. Since "cholinergic' analgesia is mediated independently of the opiate system, the possibility was considered that this response was mediated through inhibition of the local release of substance P. Rats were prepared with indwelling i.t. catheters which terminated in the L2-L3 region of the spinal cord. I.t. injection of carbachol (0.05-5 micrograms) or neostigmine (1-10 micrograms), but not nicotine (0.5-10 micrograms) produced dose-related increases in tail flick latencies. Pretreatment with i.t. injection of atropine or hemicholinium-3 significantly inhibited the antinociceptive response to neostigmine. Spinal substance P levels were measured 30 min following 0.5 micrograms carbachol. Levels in the dorsal horn were reduced by 30% compared with saline controls. Levels in the ventral horn were unchanged by carbachol. These results support the role of endogenous spinal acetylcholine in pain modification and suggest an interaction with substance P neurons of the dorsal spinal cord.

Protonmotive Q cycle pathway of electron transfer and energy transduction in the three-subunit ubiquinol-cytochrome c oxidoreductase complex of Paracoccus denitrificans

Ubiquinol-cytochrome c oxidoreductase (cytochrome bc1) complex from Paracoccus denitrificans consists of only three polypeptide subunits (Yang, X., and Trumpower, B. L. (1986) J. Biol. Chem. 261, 12282-12289), whereas the analogous complexes of eukaryotic mitochondria consist of nine or more polypeptides (Schagger, H., Link, T. A., Engel, W. D., and von Jagow, G. (1986) Methods Enzymol. 126, 224-237). Using the purified three-subunit Paracoccus complex we have tested whether this simple cytochrome bc1 complex has the same electron transfer pathway and proton translocation activity as the bc1 complexes of mitochondria. Under presteady state conditions, the effects of inhibitors on reduction of cytochromes b and c1 by quinol and oxidant-induced reduction of cytochrome b indicate a cyclic electron transfer pathway and two routes of cytochrome b reduction in the three-subunit Paracoccus cytochrome bc1 complex. A novel method was developed to incorporate the cytochrome bc1 complex into liposomes with the detergent dodecyl maltoside. The enzyme reconstituted into liposomes translocated protons with an H+/2e value of 3.9. Carbonyl cyanide m-chlorophenylhydrazone eliminated proton translocation, while permitting the scalar release of protons from quinol, and thus reduced the H+/2e ratio to 2. These values agree with the predicted stoichiometries for proton translocation by a protonmotive Q cycle pathway. No inhibition of proton translocation by N',N'-dicyclohexylcarbodiimide was detected when the Paracoccus cytochrome bc1 complex was incubated with N',N'-dicyclohexylcarbodiimide before or after reconstitution into liposomes. Electron transfer in the three-subunit complex thus appears to occur by a protonmotive Q cycle pathway identical to that in mitochondrial cytochrome bc1 complexes. Only three polypeptides, cytochromes b, c1, and the Rieske iron-sulfur protein, are required for respiration and energy transduction in the cytochrome bc1 complex. The function of the supernumerary polypeptides in mitochondrial bc1 complexes is thus unclear.

Identification of a stable ubisemiquinone and characterization of the effects of ubiquinone oxidation-reduction status on the Rieske iron-sulfur protein in the three-subunit ubiquinol-cytochrome c oxidoreductase complex of Paracoccus denitrificans

The ubiquinol-cytochrome c oxidoreductase (cytochrome bc1) complex from Paracoccus denitrificans exhibits a thermodynamically stable ubisemiquinone radical detectable by EPR spectroscopy. The radical is centered at g = 2.004, is sensitive to antimycin, and has a midpoint potential at pH 8.5 of +42 mV. These properties are very similar to those of the stable ubisemiquinone (Qi) previously characterized in the cytochrome bc1 complexes of mitochondria. The micro-environment of the Rieske iron-sulfur cluster in the Paracoccus cytochrome bc1 complex changes in parallel with the redox state of the ubiquinone pool. This change is manifested as shifts in the gx, gy, and gz values of the iron-sulfur cluster EPR signal from 1.80, 1.89, and 2.02 to 1.76, 1.90, and 2.03, respectively, as ubiquinone is reduced to ubiquinol. The spectral shift is accompanied by a broadening of the signal and follows a two electron reduction curve, with a midpoint potential at pH 8.5 of +30 mV. A hydroxy analogue of ubiquinone, UHDBT, which inhibits respiration in the cytochrome bc1 complex, shifts the gx, gy, and gz values of the iron-sulfur cluster EPR signal to 1.78, 1.89, and 2.03, respectively, and raises the midpoint potential of the iron-sulfur cluster at pH 7.5 from +265 to +320 mV. These changes in the micro-environment of the Paracoccus Rieske iron-sulfur cluster are like those elicited in mitochondria. These results indicate that the cytochrome bc1 complex of P. denitrificans has a binding site for ubisemiquinone and that this site confers properties on the bound ubisemiquinone similar to those in mitochondria. In addition, the line shape of the Rieske iron-sulfur cluster changes in response to the oxidation-reduction status of ubiquinone, and the midpoint of the iron-sulfur cluster increases in the presence of a hydroxyquinone analogue of ubiquinone. The latter results are also similar to those observed in the mitochondrial cytochrome bc1 complex. However, unlike the mitochondrial complexes, which contain eight to 11 polypeptides and are thought to contain distinct quinone binding proteins, the Paracoccus cytochrome bc1 complex contains only three polypeptide subunits, cytochromes b, c1, and iron-sulfur protein. The ubisemiquinone binding site and the site at which ubiquinone and/or ubiquinol bind to affect the Rieske iron-sulfur cluster in Paracoccus thus exist in the absence of any distinct quinone binding proteins and must be composed of domains contributed by the cytochromes and/or iron-sulfur protein.

[Preparation and preliminary identification of the monoclonal antibody against esophageal carcinoma]

A series of monoclonal antibody against esophageal carcinoma was prepared by ECa109 cells immunizing Balb/c mice. Hybrids secreting antibodies reacting to ECa109 were isolated and further cloned. One monoclonal antibody, 4C3, reacted only to an esophageal cancer cell line, gastric cancer and hepatocellular carcinoma cell lines. Purified 4C3 was used in ELISA test to detect tumor cells in the esophageal epithelial cells obtained by friction balloon. The result showed that the concordance rate to the result of balloon cytosmear was 62.4% (73/117). Patients, diagnosed cytologically as dyskaryosis, were often positive in ELISA test. It is proposed that 4C3 be useful in detecting pre-cancerous lesions.

Purification of a three-subunit ubiquinol-cytochrome c oxidoreductase complex from Paracoccus denitrificans

A ubiquinol-cytochrome c oxidoreductase (cytochrome bc1) complex has been purified from the plasma membrane of aerobically grown Paracoccus denitrificans by extraction with dodecyl maltoside and ion exchange chromatography of the extract. The purified complex contains two spectrally and thermodynamically distinct b cytochromes, cytochrome c1, and a Rieske-type iron-sulfur protein. Optical spectra indicate absorption peaks at 553 nm for cytochrome c1 and at 560 and 566 nm for the high and low potential hemes of cytochrome b. The spectrum of cytochrome b560 is shifted to longer wavelength by antimycin. The Paracoccus bc1 complex consists of only three polypeptide subunits. On the basis of their relative electrophoretic mobilities, these have apparent molecular masses of 62, 39, and 20 kDa. The 62- and 39-kDa subunits have been identified as cytochromes c1 and b, respectively. The 20-kDa subunit is assumed to be the Rieske-type iron-sulfur protein on the basis of its molecular weight and the presence of an EPR-detectable signal typical of this iron-sulfur protein in the three-subunit complex. The Paracoccus bc1 complex catalyzes reduction of cytochrome c by ubiquinol with a turnover of 470 s-1. This activity is inhibited by antimycin, myxothiazol, stigmatellin, and hydroxyquinone analogues of ubiquinone, all of which inhibit electron transfer in the cytochrome bc1 complex of the mitochondrial respiratory chain. The electron transfer functions of the Paracoccus complex thus appear to be similar, and possibly identical, to those of the bc1 complex of eukaryotic mitochondria. The Paracoccus bc1 complex has the simplest subunit composition and one of the highest turnover numbers of any bc1 complex isolated from any species to date. These properties suggest that the structural requirements for electron transfer from ubiquinol to cytochrome c are met by a small number of peptides and that the "extra" peptides occurring in the mitochondrial bc1 complexes serve some other function(s), possibly in biogenesis or insertion of the complex into that organelle.

Elemental Anomalies at the Cretaceous-Tertiary Boundary, Woodside Creek, New Zealand

Iridium and 26 other elements were determined in shale from the Cretaceous-Tertiary boundary at the locus classicus (for iridium anomalies) at Woodside Creek, New Zealand. Iridium, gold, copper, cobalt, chromium, nickel, arsenic, molybdenum, and iron were enriched in the basal 2 millimeters of the 8-millimeter shale parting as compared with the rest of the stratigraphic column. No other shale partings in the column had anomalous concentrations of any element when the data were expressed on a carbonate-free basis. The boundary material showed striking compositional similarities with the Stevns Klint Danish boundary shale. Elemental concentrations were in general much higher in the New Zealand material than in nonboundary shales from elsewhere in the world. The high concentration of iridium (153 nanograms per gram) in the basal layer of the boundary, together with the enrichment of other siderophile elements supports the idea of an extraterrestrial source for much of the material. The iridium/gold ratio of 2.1 is also in accordance with such a source. The iridium content of the basal layer is higher than for any other marine boundary shale obtained on land. The integrated iridium value is 187 nanograms per square centimeter of boundary surface.