Depletion of a gamma delta T cell subset can increase host resistance to a bacterial infection

Gammadelta T lymphocytes have been shown to regulate immune responses in diverse experimental systems. Because distinct gammadelta T cell subsets, as defined by the usage of certain TCR V genes, preferentially respond in various diseases and disease models, we have hypothesized that the various gammadelta T cell subsets carry out different functions. To test this, we compared one particular gammadelta T cell subset, the Vgamma1(+) subset, which represents a major gammadelta T cell type in the lymphoid organs and blood of mice, to other subsets and to gammadelta T cells as a whole. Using Listeria monocytogenes infection as an infectious disease model, we found that bacterial containment improves in mice depleted of Vgamma1(+) gammadelta T cells, albeit mice lacking all gammadelta T cells are instead impaired in their ability to control Listeria expansion. Our findings indicate that Vgamma1(+) gammadelta T cells reduce the ability of the innate immune system to destroy Listeria, even though other gammadelta T cells as a whole promote clearance of this pathogen.

Coupling estimated effects of QTLs for physiological traits to a crop growth model: predicting yield variation among recombinant inbred lines in barley

Advances in the use of molecular markers to elucidate the inheritance of quantitative traits enable the integration of genetic information on physiological traits into crop growth models. The objective of this study was to assess the ability of a crop growth model with QTL-based estimates of physiological input parameters to predict the yield of recombinant inbred lines (RILs) of barley. The model used predicts yield as spike biomass accumulated over the post-flowering period. We describe a two-stage procedure for predicting trait values from estimated additive and epistatic effects of QTLs. Values of physiological traits estimated by that procedure or measured in the field were used as input to the crop growth model. The output values (yield and shoot biomass) from the growth model using these two types of input values were highly correlated, indicating that QTL information can successfully replace measured input parameters. With the current crop growth model, however, both types of input values often resulted in large discrepancies between observed and predicted values. Improvement of performance may be achieved by incorporating physiological processes not yet included in the model. The prospects of using QTL-based predictions of model-input traits to identify new, high yielding barley genotypes are discussed.

[The application study of mimic operation with 3D-cut in maxillofacial bone tumor]

OBJECTIVE

To study the feasibility of guiding operation planning and complication prevention.

METHODS

Ten patients suffer from Maxillofacial bone tumour were examined with spiral CT. Firstly, to get three-dimensional reconstructive image of tumour and other tissues. Secondly, use 3D-cut software to cut off every layer of normal tissue and tumour mass. Lastly, to compare virtual operation with mimic operation in virtual operation process.

RESULTS

Three-dimensional mimic operation clearly displays the relationship between tumor and surrounding tissues, reflect the actual operation condition.

CONCLUSIONS

It is very useful designing operation program and predicting the potential complications before the actual operation.

Promotion of growth and apoptosis in c-myc nullizygous fibroblasts by other members of the myc oncoprotein family

c-myc nullizygous fibroblasts (KO cells) were used to compare the abilities of c-myc, N-myc and L-myc oncoproteins to accelerate growth, promote apoptosis, revert morphology, and regulate the expression of previously described c-myc target genes. All three myc oncoproteins were expressed following retroviral transduction of KO cells. The proteins all enhanced the growth rate of KO cells and significantly shortened the cell cycle transition time. They also accelerated apoptosis following serum deprivation, reverted the abnormal KO cell morphology, and modulated the expression of previously described c-myc target genes. In most cases, L-myc was equivalent to c-myc and N-myc in restoring all of the c-myc-dependent activities. These findings contrast with the previously reported weak transforming and transactivating properties of L-myc. Myc oncoproteins may thus impart both highly similar as well as dissimilar signals to the cells in which they are expressed.

[A case-control study on the relationship between abnormal homocysteine metabolism and essential hypertension]

OBJECTIVE

To examine the relationship between abnormal homocysteine metabolism and essential hypertension in a Chinese population, a community-based case-control study was conducted.

METHODS

127 essential hypertensive patients aged 35 to 75 were randomly selected from a community. Another 170 control subjects with blood pressure < 140/90 mmHg were selected from the same community. Serum homocysteine was determined using HPLC. Folate and vitamin B(12) were measured by radioimmunoassay. MTHFR genotypes were identified by PCR and restriction fragment length polymorphism analysis with Hinf I digestion.

RESULTS

After adjusting for age and sex, the mean homocysteine level was 10.56 micromol/L for hypertensive patients and 10.34 micromol/L for controls (F = 0.234, P = 0.63). No association between either SBP or DBP and Hcy concentration was found in subjects without anti-hypertensive medications. The prevalence of homozygousity for thermolabile MTHFR variant for this population was 13.1%, and the mutant allele frequency was 38.7%. There was no significant difference on genotype distributions and the mutant allele frequency for the two studied groups. However, the concentrations of folate and B(12) for the hypertensive subjects were generally higher than the controls.

CONCLUSIONS

The present study did not discover that the elevation of Hcy levels or MTHFR mutation were independent risk factors for essential hypertension. The higher folate and B(12) in the hypertensive subjects might contribute to a lower risk.

Oncogenic base substitution mutations in circulating leukocytes of normal individuals

The background frequency of mutations in human tissues is an important issue in cancer susceptibility and genotoxic exposure determinations. Here we report the detection of rare mutant leukocytes containing oncogenic base substitutions of the Harvey-ras, N-ras, and p53 genes by the Needle-in-a-Haystack mutation assay with a sensitivity of one cell in a million. Altogether, we detected and identified 17 independent mutations of 66 separate base site analyses of peripheral blood specimens obtained from 19 apparently normal individuals. Two individuals harbored a substantially increased frequency of mutant cells, representing 9 of the 17 independent mutations found. These results suggest that up to 1 in 10 normal individuals may harbor a significant frequency of oncogenic mutations in circulating leukocytes.

[Effects of glycidyl methacrylate on gap junctional intercellular communication]

In order to probe into the mechanism of glycidyl methacrylate (GMA)-induced cell transformation, the effects of GMA on gap junctional intercellular communication (GJIC) in human lung, embryonic fibroblasts(HLEF) were studied by using scrape-loading and dye transfer(SLDT) technique. HLEF cells were treated with GMA at concentrations of 0.5, 2.5 and 5.0 mg/L for 12 hours and Lucifer Yellow was introduced by scrape-loading after exposure. The GJIC in exposed cells and that of control were determined directly as the diffusion extent of fluorescent dye into adjacent cells. The results indicated that GMA could inhibit the GJIC in exposed cells in a dose-dependent manner. Significantly decreased GJIC was found in 2.5 and 5.0 mg/L dose groups. It was suggested that the inhibition of GJIC might be one of the mechanisms responsible for GMA-induced cell transformation.

Casein kinase II phosphorylates lens connexin 45.6 and is involved in its degradation

Connexin (Cx) 45.6, an avian counterpart of rodent Cx50, is phosphorylated in vivo, but the sites and function of the phosphorylation have not been elucidated. Our peptide mapping experiments showed that the Ser(363) site in the carboxyl (COOH) terminus of Cx45.6 was phosphorylated and that this site is within casein kinase (CK) II consensus sequence, although showing some similarity to CKI sequence. The peptide containing Ser(363) could be phosphorylated in vitro by CKII, but not by CKI. Furthermore, CKII phosphorylated Cx45.6 in embryonic lens membrane and the fusion protein containing the COOH terminus of Cx45.6. Two-dimensional peptide mapping experiments showed that one of the Cx45.6 peptides phosphorylated in vivo migrated to the same spot as one of those phosphorylated by CKII in vitro. Furthermore, CKII activity could be detected in lens lysates. To assess the function of this phosphorylation event, exogenous wild type and mutant Cx45.6 (Ser(363) --> Ala) were expressed in lens primary cultures by retroviral infection. The mutant Cx45.6 was shown to be more stable having a longer half-life compared with wild type Cx45.6. Together, the evidence suggests that CKII is likely a kinase responsible for the Ser(363) phosphorylation, leading to the destablization and degradation of Cx45.6. The connexin degradation induced by phosphorylation has a broad functional significance in the regulation of gap junctions in vivo.

Schwann cell myelination requires timely and precise targeting of P(0) protein

This report investigated mechanisms responsible for failed Schwann cell myelination in mice that overexpress P(0) (P(0)(tg)), the major structural protein of PNS myelin. Quantitative ultrastructural immunocytochemistry established that P(0) protein was mistargeted to abaxonal, periaxonal, and mesaxon membranes in P(0)(tg) Schwann cells with arrested myelination. The extracellular leaflets of P(0)-containing mesaxon membranes were closely apposed with periodicities of compact myelin. The myelin-associated glycoprotein was appropriately sorted in the Golgi apparatus and targeted to periaxonal membranes. In adult mice, occasional Schwann cells myelinated axons possibly with the aid of endocytic removal of mistargeted P(0). These results indicate that P(0) gene multiplication causes P(0) mistargeting to mesaxon membranes, and through obligate P(0) homophilic adhesion, renders these dynamic membranes inert and halts myelination.

P(0) glycoprotein overexpression causes congenital hypomyelination of peripheral nerves

We show that normal peripheral nerve myelination depends on strict dosage of the most abundantly expressed myelin gene, myelin protein zero (Mpz). Transgenic mice containing extra copies of Mpz manifested a dose-dependent, dysmyelinating neuropathy, ranging from transient perinatal hypomyelination to arrested myelination and impaired sorting of axons by Schwann cells. Myelination was restored by breeding the transgene into the Mpz-null background, demonstrating that dysmyelination does not result from a structural alteration or Schwann cell-extrinsic effect of the transgenic P(0) glycoprotein. Mpz mRNA overexpression ranged from 30-700%, whereas an increased level of P(0) protein was detected only in nerves of low copy-number animals. Breeding experiments placed the threshold for dysmyelination between 30 and 80% Mpz overexpression. These data reveal new points in nerve development at which Schwann cells are susceptible to increased gene dosage, and suggest a novel basis for hereditary neuropathy.

Detection of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 2(PAI-2) in gingival crevicular fluid from healthy, gingivitis and periodontitis patients

BACKGROUND

The regulation of plasminogen activation is a key element in controlling proteolytic events in the extracellular matrix. Our previous studies had demonstrated that in inflamed gingival tissues, tissue-type plasminogen activator (t-PA) is significantly increased in the extracellular matrix of the connective tissue and that interleukin 1beta(IL-1beta) can up regulate the level of t-PA and plasminogen activator inhibitor-2 (PAI-2) synthesis by human gingival fibroblasts.

METHOD

In the present study, the levels of t-PA and PAI-2 in gingival crevicular fluid (GCF) were measured from healthy, gingivitis and periodontitis sites and compared before and after periodontal treatment. Crevicular fluid from106 periodontal sites in 33 patients were collected. 24 sites from 11 periodontitis patients received periodontal treatment after the first sample collection and post-treatment samples were collected 14 days after treatment. All samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for t-PA and PAI-2.

RESULTS

The results showed that significantly high levels of t-PA and PAI-2 in GCF were found in the gingivitis and periodontitis sites. Periodontal treatment led to significant decreases of PAI-2, but not t-PA, after 14 days. A significant positive linear correlation was found between t-PA and PAI-2 in GCF (r=0.80, p<0.01). In the healthy group, different sites from within the same subject showed little variation of t-PA and PAI-2 in GCF. However, the gingivitis and periodontitis sites showed large variation. These results suggest a good correlation between t-PA and PAI-2 with the severity of periodontal conditions.

CONCLUSION

This study indicates that t-PA and PAI-2 may play a significant rôle in the periodontal tissue destruction and tissue remodeling and that t-PA and PAI-2 in GCF may be used as clinical markers to evaluate the periodontal diseases and assess treatment.

Species-specific detection of hydrocarbon-utilizing bacteria

Rapid detection and quantitative assessment of specific microbial species in environmental samples is desirable for monitoring changes in ecosystems and for tracking natural or introduced microbial species during bioremediation of contaminated sites. In the interests of developing rapid tests for hydrocarbon-degrading bacteria, species-specific PCR primer sets have been developed for Pseudomonas aeruginosa, Stentrophomonas (Xanthomonas) maltophilia, and Serratia marsescens. Highly variable regions of the 16S rRNA gene were used to design these primer sets. The amplification products of these primer sets have been verified and validated with hemi-nested PCR and with ligase chain reaction (LCR) techniques, and have been applied to the analyses of environmental water samples. These species-specific primer sets were also chosen to amplify in conjunction with a universal set of PCR primers chosen from highly conserved neighboring sequences in the same gene. These multiplex or competitive PCR procedures enable testing with an internal marker and/or the quantitative estimation of the relative proportion of the microbial community that any one of these species occupies. In addition, this universal PCR primer set amplified the same size amplicon from a wide spectrum of procaryotic and eucaryotic organisms and may have potential in earth biota analyses.

[Hepatic arterial infusion of 32P-radionuclide microspheres for radiation therapy of hepatocellular carcinoma]

OBJECTIVE

To investigate the efficacy of internal radiation of (32)P-glass microspheres ((32)P-GMS) in unresected hepatocellular carcinoma (HCC) via subcutaneous arterial port.

METHODS

Hepatic arterial (99)technetium-macroaggregate albumin ((99)Tc-MAA) scanning via subcutaneous arterial port was undertaken to measure lung/liver shunting ratio and tumor/liver ratio. Hepatic arterial infusion of (32)P-GMS was performed in 17 cases of HCC with a dose from 1.11 to 1.30 GBq. Twenty cases of HCC undergoing hepatic arterial chemoembolization (HACE) in the same period served as controls group.

RESULTS

There was no treatment-related death in the 17 cases. In 7 of the 17 cases, AFP level and/or tumor size decreased by 50% after treatment, with a response rate of 64.7%. The median survival time was 5.5 months, and the 3-, 6-, 9-, 12-month survival rates were 94.1%, 44.1%, 31.0%, 24.4%, respectively. The therapeutic efficacy was better than that of HACE. The survival time was significantly longer in patients with T/N ratio >or= 2 than in those with T/N < 2 (P < 0.05).

CONCLUSIONS

Hepatic arterial infusion of (32)P-GMS is an alternative treatment for unresected HCC.

[Histological studies on rinds of 18 species of Gualou]

OBJECTIVE

To make clear the histological characteristics of rinds for eighteen species of Gualou.

METHOD

Observing the cross sections and separate divide of the rinds with light microscope.

RESULT AND CONCLUSION

Of eighteen rinds of Gualou, each trichome on exocarp, wood fiber and thickness of ring of stone cell are different from one another, this distinction can be used to identify the different rinds of Gualou.

[Study on expression of apoptosis related genes in non-small cell carcinoma]

OBJECTIVE

To study the relationship between the expression of apoptosis related genes in the tissue of non-small cell lung carcinoma (NSCLC) and clinicopathology in the tumor.

METHODS

The expression of bcl-2, bax, Fas and FasL were detected with immunohistochemistry method in 45 cases of NSCLC.

RESULTS

23 (51%) cases of NSCLC were bcl-2 positive, 38 (84%) were bax positive (P < 0.01), and there was no significant correlation between the expression of bcl-2 and bax protein, but a positive relationship was found between the expression of Fas and FasL (P < 0.01). The positive rate of bcl-2 expression decreased in advanced stages of NSCLC(P < 0.05), the bax expression was lower in cases with poor cell differentiation (P < 0.05), and the FasL expression was higher in adenocarcinoma (P < 0.01). The simultaneous expression of bcl-2 and bax protein was closely correlated with TNM stages (P < 0.05), the differences of bcl-2 protein expression alone in NSCLC with cell differentiation were statistically significant (P = 0.033).

CONCLUSIONS

Both bcl-2, bax, Fas and FasL may involve in the regulation of apoptosis and may play an important role in the occurrence and progression of NSCLC.

Needle-in-a-haystack detection and identification of base substitution mutations in human tissues

Background and induced germline mutagenesis and other genotoxicity studies have been hampered by the lack of a sufficiently sensitive technique for detecting mutations in a small cluster of cells or a single cell in a tissue sample composed of millions of cells. The most frequent type of genetic alteration is intragenic. The vast majority of oncogenic mutations in human and mammalian cancer involves only single base substitutions. We have developed universally applicable techniques that not only provide the necessary sensitivity and specificity for site specific mutagenesis studies, but also identify the point mutation. The exponential amplification procedures of polymerase chain reaction (PCR) and ligase chain reaction (LCR) have been combined with restriction endonuclease (RE) digestion to enable the selective enrichment and detection of single base substitution mutations in human oncogenic loci at a sensitivity of one mutant in more than 10(7) wild type alleles. These PCR/RE/LCR procedures have been successfully designed and used for codons 12 and 248 of the Ha-ras and p53 genes, respectively, both of which contain a natural MspI restriction endonuclease recognition sequence. These procedures have also been adapted for the detection and identification of mutations in oncogenic loci that do not contain a natural restriction endonuclease recognition sequence. Using PCR techniques, a HphI site was incorporated into the codons 12/13 region of the human N-ras gene, which was then used for the selective enrichment of mutants at this oncogenic locus. These PCR/RE/LCR procedures for base substitution mutations in codon 12 of the N-ras gene were found to have the sensitivity of detection of at least one mutant allele in the presence of the DNA equivalent of 10(6) wild type cells. Only one peripheral blood leukocyte DNA specimen out of nine normal individuals displayed an observable Ha-ras mutation that was present at frequency between 10(-5) and 10(-6). These PCR/RE/LCR techniques for detecting and identifying base substitution mutations are universally applicable to almost any locus or base site within the human or animal genome. With the added advantage of the adjustability of both the amount of DNA (number of genomes) to be tested and the sensitivity (10(-2) to 10(-7)) of the assay selection or enrichment procedures, these PCR/RE/LCR techniques will be useful in addressing a broad range of important questions in mutagenesis and carcinogenesis.

Determination of icariin in Chinese traditional medicine by capillary zone electrophoresis

Icariin in Chinese traditional medicine was determined by an accurate and simple capillary zone electrophoresis method which used 30 mmol/L of borate solution containing 10% of acetonitrile as running buffer and needed no pretreatment.

A familial case of Alzheimer's disease without tau pathology may be linked with chromosome 3 markers

Alzheimer's disease is the most common form of dementia that occurs in later years. The diagnosis is confirmed by the pathological findings of betaA4-amyloid-containing neuritic plaques and neurofibrillary tangles, the former being present in sufficient quantity commensurate with age. Other forms of dementia are more difficult to diagnose clinically; their pathology is noted for the lack of plaques and tangles. A patient with a family history of dementia presented with the clinical signs of Alzheimer's disease which lasted for 13 years. At autopsy the brain tissue had betaA4-amyloid-containing neuritic plaques, but no neurofibrillary tangles (i.e., the tissue was negative for staining with the tau antibody). Genetic analysis of DNA from family members revealed no linkage with chromosome 17 markers, indicating that this was not frontotemporal dementia. However, there was linkage with chromosome 3 markers. Thus, this form of Alzheimer's disease with a pathology of plaques only is linked with markers on chromosome 3.

[Effects of tantalum and its oxide on exposed workers]

OBJECTIVE

To explore effects of tantalum and its oxide on the exposed workers.

METHODS

Health examination for 113 workers exposed to tantalum and its oxide and a field survey for occupational hygiene in the workplace were carried out.

RESULTS

Workplace air concentration of tantalum and its oxide averaged 0.1 - 7.6 mg/m(3). There was no significant difference in prevalence of symptoms and signs and biochemical, pulmonary function, chest X-ray and electrocardiograph examinations between the exposed and control workers.

CONCLUSION

No adverse effect of tantalum and its oxide on the exposed workers was found.

[Morphological studies on 18 species of gualoupi]

OBJECTIVE

To gain a clear idea of the drug Gualoupi and its adulterants.

METHOD

Collecting data and spot investigating in 30 provinces, cities and autonomous regions in China.

RESULT

Gualoupi used as drug in China consists of 15 species of Trichosanthes, 1 species of Momordica, 1 species of Citrullus and 1 species of Adenia(Passifloraceae).

CONCLUSION

The main commodity is the rind of T. kirilowii or T. rosthornii, and the main adulterant is the rind of T. hupehensis.

Portal hemodynamics in cirrhotics with portal hypertension using color Doppler velocity profile

OBJECTIVE

To investigate portal hemodynamics and its correlation with esophageal variceal bleeding (EVB) in cirrhotics with portal hypertension by using a newly-developed technique, color Doppler velocity profile (CDVP).

METHODS

Hemodynamics of portal trunk (PT), right anterior branch (RAB) and splenic vein (SV) were evaluated in 48 cirrhotics with portal hypertension and 35 normal volunteers by CDVP. The parameters included maximum cross-sectional velocity (CS-Vmax), flow volume, congestion index (CI), profile parameter N and pattern of flow curve. Stepwise logistic regression model was employed to determine EVB-relating factors in cirrhotics.

RESULTS

CS-Vmax in PT and RAB was significantly lower in cirrhotic group than that of normal group, being 14.91 +/- 3.08 cm/s, 9.44 +/- 2.70 cm/s vs 30.52 +/- 6.75 cm/s, 12.82 +/- 2.69 cm/s, respectively (P < 0.01 for both). Flow volume of PT and SV was significantly higher in cirrhotic group compared with that of normal group, being 25.16 +/- 10.48 ml.min-1.kg-1, 15.83 +/- 9.18 ml.min-1.kg-1 vs 20.43 +/- 5.57 ml.min-1.kg-1, 5.81 +/- 2.04 ml.min-1.kg-1, respectively (P < 0.01 for both). CI of PT, RAB and SV was significantly higher in cirrhotic group than in normal group, being 0.142 +/- 0.0654, 0.105 +/- 0.0496, 0.0884 +/- 0.0431 vs 0.0326 +/- 0.0142, 0.0757 +/- 0.0342, 0.0483 +/- 0.0230, respectively (P < 0.01 for all). In dynamic variation of flow volume over time, RAB and SV in cirrhotic group increasingly presented flat pattern and periodically changed pattern, respectively (P < 0.01 for both). Between cirrhotic subgroups without and with EVB history, there were significant differences in flow volume, CI and N value of SV, splenic size, degree of esophageal varices (EV) and portal hypertensive gastropathy (PHG), and stepwise logistic regression revealed that N value of SV, splenic size, degree of EV and PHG were four independent factors in relation to EVB. EVB scores calculated from the regression equation had a close correlation with EVB. In patients with EVB score > 0, 88.9% of them had EVB, and in those with EVB < 0, 76.9% of them had no history of EVB.

CONCLUSION

In cirrhotics with portal hypertension, portal venous system has the features of elevated vascular resistance and hyperdynamics, and the latter mainly results from increased blood flow in SV. EVB score may become a valuable parameter in predicting occurrence of EVB.

Axonal pathology in myelin disorders

Myelination provides extrinsic trophic signals that influence normal maturation and long-term survival of axons. The extent of axonal involvement in diseases affecting myelin or myelin forming cells has traditionally been underestimated. There are, however, many examples of axon damage as a consequence of dysmyelinating or demyelinating disorders. More than a century ago, Charcot described the pathology of multiple sclerosis (MS) in terms of demyelination and relative sparing of axons. Recent reports demonstrate a strong correlation between inflammatory demyelination in MS lesions and axonal transection, indicating axonal loss at disease onset. Disruption of axons is also observed in experimental allergic encephalomyelitis and in Theiler's murine encephalomyelitis virus disease, two animal models of inflammatory demyelinating CNS disease. A number of dysmyelinating mouse mutants with axonal pathology have provided insights regarding cellular and molecular mechanisms of axon degeneration. For example, the myelin-associated glycoprotein and proteolipid protein have been shown to be essential for mediating myelin-derived trophic signals to axons. Patients with the inherited peripheral neuropathy Charcot-Marie Tooth disease type 1 develop symptomatic progressive axonal loss due to abnormal Schwann cell expression of peripheral myelin protein 22. The data summarized in this review indicate that axonal damage is an integral part of myelin disease, and that loss of axons contributes to the irreversible functional impairment observed in affected individuals. Early neuroprotection should be considered as an additional therapeutic option for these patients.

[Experimental study on antiendotoxin effect of extracts from Artemisia annua L]

OBJECTIVE

To explore the antiendotoxin effect of extracts from Artemisia annua (AA) and qinghaosu (QHS).

METHOD

LPO and SOD in chondriosome, ACP in lysosomes, tumor nicrosis factor-alpha(TNF-alpha) and endotoxin in plasma, and P450 concentration in hepatic microsome of rats were determined. Mortality of endotoxemic mice and histomorphology were observed.

RESULT

LPO, ACP, endotoxin, TNF-alpha and P450 content were decreased with AA and QHS. SOD activity was increased with AA and QHS. At the same time, mortality was decreased. Histomorphology of lysosomes and chondriosome of rats were protected from endotoxin.

CONCLUSION

AA and QHS possess an antiendotoxin effect.