[Changes of brain potentials related to visual attention during simulated weightlessness]

To study the possible effect of simulated weightlessness on brain function state, the brain event-related potentials (ERPs) during a simple visual selective response task were compared between head down tilt (HDT) and head up tilt (HUT) in 9 normal subjects. The results were: both the target (T) and non-target (NT) flash signals induced significant slow positive potentials which were supposed to be related to the attention activity; the amplitude of the positive potentials in the frontal regions decreased significantly especially for NT-ERPs during HDT as compared with that during HUT. The data provide new evidence indicating that the ability of brain response declined during simulated weightlessness and more attention should be paid to the study of brain function during space flight.

[Hypolipidemic action of soy fiber and its effects on platelet aggregation and coagulation time in rats]

In order to lay a scientific basis for the development and use of soy bean, six per cent of soy fiber (SF) and pure cellulose were added to normal feed containing 1% of cholesterol and 0.2% bile salt, to feed SD rats, as compared with a control group of rats fed only with the normal feed, to study the effects of fibers on blood lipid concentration, platelet aggregation and clotting time. Results showed SF could not only significantly lower serum total cholesterol (TC), LDL-C and atherosclerotic index, and increase the ratio of HDL-L/TC, but also significantly lower serum fibrinogen (FB) and platelet aggregation, prolong clotting time (P < 0.01). NO such effects were observed in rats fed with pure cellulose. The authors believed that hypolipidemic effect of SF was achieved by lowering LDL-C in animals with hyperlipemia, and lowering of blood lipid and FB were major reasons to make animals fed with SF-added feed lower their platelet aggregation and prolong their clotting time.

The regulation of pulmonary vascular tone

1. The ability to manipulate pharmacologically pulmonary vascular tone independent of effects on systemic blood vessels is a desirable objective. Elucidation of the biochemical mechanisms underlying hypoxia-induced pulmonary vasoconstriction (HPV) may permit preferential targeting of the pulmonary circulation. 2. Here we review our studies of the role of locally synthesized candidate vasoactive factors in HPV. In addition, we present data demonstrating an attenuated pressor response to hypoxia in the pulmonary circulation of Fischer 344 rats compared with the Wistar-Kyoto (WKY) rat strain. 3. We propose that a systematic genome-wide search using the HPV phenotype and a panel of highly informative microsatellite markers will elucidate the genetic loci underlying the difference in susceptibility to HPV in these two rat strains and provide a valuable and novel insight into the factors that determine the HPV response.

[Intellectual status of patents cerebral cysticercosis]

OBJECTIVE

To study the intellectual status of patients with cerebral cysticercosis with dementia evaluation scale.

METHODS

The intellectual status of 112 patients with cerebral cysticercosis was studied with Hasagawa dementia evaluation scale and that of 30 patients with event related potential of P 300.

RESULTS

In the patientsl, 50.9% suffered from mental dysfunction. Among them 11.6% had severe abnormality, 13.4% moderate, and 25.9% mild. Hypertension, epileptic attack and improper medication may cause intellectual dysfunction.

CONCLUSIONS

Protection of mental function should be considered when chosing the treatment for better recovery of the patients. Hypertension, epileptic attack and improper medication may cause intellectual dysfunction.

Initial characterization of viral sequences from a SHIV-inoculated pig-tailed macaque that developed AIDS

In this study, we report on the derivation of a pathogenic SIV-HIV chimeric virus (SHIV) and the initial characterization of the viral sequences from the first (macaque PPc) of a series of pig-tailed macaques that developed CD4+ T cell loss and AIDS. Viral genes were amplified by PCR from the brain, lymphoid, and kidney tissues and their sequences compared to the original SHIV used to initiate passages in macaques. Our results show that the vpu gene, which was nonfunctional in the original SHIV, now coded for functional protein in macaque PPc. The tat and rev genes had no consensus changes but the nef gene had 4-5 consensus changes, depending on the tissue examined. The gp 120 gene had the highest number of nucleotide and amino acid substitution rates that varied from 0.64% to 1.44% and 1.17% to 3.71%, respectively, again depending on the tissue examined. These results suggest that a constellation of changes accumulated at the genomic level during the derivation of a SHIV that was pathogenic for pig-tailed macaques.

Systemic uptake and clearance of chloroform by hairless rats following dermal exposure. I. Brief exposure to aqueous solutions

The systemic uptake of chloroform from dilute aqueous solutions into live hairless rats under conditions simulating dermal environmental exposure was studied. Whole blood was sampled during a 30-min immersion of an animal within water containing a known concentration of chloroform and then for 5.5 h following its removal from the bath. The amount of chloroform systemically absorbed was determined by comparing the AUCs of the blood concentration vs. time plots from dermal exposure to that obtained after i.v. infusion (for a period of 30 min) of an aqueous solution containing a known amount of chloroform (positive control). Although dermal data implied two-compartment disposition characteristics, i.v. infusion data fit best to a three-compartment disposition. Linear pharmacokinetics was observed both by i.v. administration and percutaneous absorption at the dose levels studied. Chloroform was detected in the rat blood as early as 4 min following exposure. Our findings suggest that about 10.2 mg of chloroform was systemically absorbed after dermal exposure of a rat to an aqueous solution of 0.44 mg/ml. This amount is substantially higher than the predictions of mathematical risk-models put forth by some investigators. However, when expressed as the "effective" permeability coefficient (Kpeff), close agreement was noticed between our value and those estimated by others using physiologically based pharmacokinetic (PBPK) models. Also, in terms of Kpeff, reasonable agreement existed between our and another investigator's past estimates of uptake based on depletion of bath level of chloroform and the actual uptake measured in our current experiments. The estimated onset of systemic entry seen here is entirely consistent with our estimate of how long it takes to establish the diffusion gradient across the stratum corneum based on tape stripping.

In vivo and in vitro effects of epidermal growth factor on its receptor gene expression in rat dental follicle cells

Epidermal growth factor receptor (EGFR) is known to be localized early postnatally in the follicle of rat mandibular molars and to decline later. Here, EGFR mRNA present early postnatally in the follicle was revealed by in situ hybridization and reverse transcription-polymerase chain reaction. Injections of epidermal growth factor (EGF) enhanced the expression of EGFR mRNA but not EGF mRNA through day 5 postnatally in the follicle. By day 7 postnatally, the amount of EGFR mRNA was dramatically reduced and EGF injection at that time or later did not enhance its expression. Cultured dental follicle cells were also shown to contain both EGFR mRNA and EGF mRNA, but only EGFR mRNA expression was enhanced after incubation of the cells with EGF. The EGFR mRNA was apparently translated, because the cultured cells could be immunostained for EGFR. This enhancement of EGFR mRNA in the dental follicle cells by EGF may be a necessary prelude to the mitogenic effect of EGF on the cultured cells because incubating the dental follicle cells in EGF over 6 days resulted in almost a doubling in their number as compared to controls. These results indicate that the tissue necessary for eruption to occur, the dental follicle, contains EGFR mRNA in the early postnatal days. In turn, this mRNA is enhanced by EGF, a molecule known to accelerate eruption if injected early postnatally. Whether or not the mitogenic effect of the EGF on the cultured dental follicle cells is a mechanistic factor that contributes to the subsequent tooth eruption is unknown.

[Preliminary investigation of Helicobacter pylori infection in Linqu County of Shandong province]

A preliminary epidemiological investigation of Helicobacter pylori (HP) infection was performed with 13C-urea breathing test for 218 residents at the age from 40 to 69 years in a high risk area of gatric cancer, Linqu County of Shandong province. Our results show an overall HP infection rate of 71.10%, or 69.49% for men and 73.00% for women. The HP infection rate in the group of serious chronic atrophic gastritis was significantly higher than that of mild chronic atrophic gatritis (P < 0.05). The HP positive group also has a higher rate of complaining about gastric discomfort than the HP negative group (P < 0.02).

[Study on the test and evaluation of the toxicity of the strains preparation of the different subspecies of Bacillus thuringiensis and on the research into its standardization]

In this paper using the preparation of Bacillus thuringiensis of USA standard sample-subsp. kurstaki HD-1-S-1980 (H3a3b) the toxicity to different subspecies preparations such as subsp. dendrolimus U strain(H4a4b), subsp. galleriae C88 strain (H5a5b) is tested and evaluated. And product's standardization is also researched. Comparing their toxicity to various test-insects between the standard sample prepared from U strain and USA, standard sample, the boilogical determined results are as follows: the toxicity of U strain standard sample is respectively 18666.6 IU/mg(test-insects: Dendrolimus punctatus, 2nd larva), 22956.5 IU/mg(test-insects: Plutella kylostella, 2nd larva). The above-mentioned toxicity evaluations are higher than that of 16000 IU/mg of USA standard sample. The comparison in susceptibility shows as follows: suscepticibility of plutella kylostella is stronger than that of Dendrolimus punctatus. The products from U strain and C88 strain are trial-produced in medium-scale. The product's toxicity to test-insect Dendrolimus punctatus is determined using USA standard sample. The results are obtained as follows the toxicity evaluation of U strain products is 36444.4 IU/mg; that of C88 strain products is 28521.7 IU/mg. The both are obviously higher than that of USA standard sample. This proves that different subspecies strain's toxicity to the same test-insect is with defference and it is an important way to raise product's toxicity by improving and optimizing process in production. The whole experiment shows it is feasible to rectify the evaluation of the toxicity of our country's present products using USA standard sample, Dendrolimus punctatus and Plutella kylostella as test-insets. And it is simple and convienient as well as save time and save effort to make statistical analysis in computer with Basic program. To do statistical and operational analysis using our designed basic programming by micro-computer is more accurate and repid than by caculator.

[Effects of sand and hormone treatment on seed germination of Bupleurum chinese DC. and B. falcatum L]

The seeds of Bupleurum chinese and B. falcatum were treated first by GA3 or 6-BA in different concentrations and then by sand. The best method for promoting their germination has been developed.

Effects of epidermal growth factor (EGF) and colony-stimulating factor-1 (CSF-1) on expression of c-fos in rat mandibular molars: implications for tooth eruption

The c-fos gene is expressed in the dental follicle of the first mandibular molar of rats. Molecules that accelerate tooth eruption, epidermal growth factor (EGF) and colony-stimulating factor-1 (CSF-1), enhance the expression of the c-fos gene in vitro in both a time- and concentration-dependent manner. In vivo, EGF enhances c-fos expression in the follicle from day 0-7 postnatally, but by day 9 the follicle is refractory to this stimulus. Immunostaining reveals that the c-fos gene is translated in the cultured dental follicle cells, with staining seen in the nucleus and the perinuclear region of the cytoplasm. In vivo, immunostaining for c-fos is prominent in the dental follicle early postnatally, with little or no staining seen in the stellate reticulum and dental pulp. By day 10 postnatally, staining for c-fos is greatly reduced in the dental follicle. Thus, the presence of c-fos early postnatally in the tissue required for eruption, the dental follicle, as well as the enhancement of c-fos gene expression in the follicle by EGF or CSF-1, suggests that c-fos plays a role in tooth eruption. That role may be either to promote differentiation of mononuclear cells into osteoclasts needed for eruption or to recruit the mononuclear cells into the follicle.

Regulation of cytokine mRNA expression in activated lymphocytes by human choriocarcinoma JAR cells

Because the fetus is semiallogenic to the mother, considerable modulation of the maternal immune response must occur in order for pregnancy to be successfully carried to term. Some authors have hypothesized that the immunomodulation of pregnancy includes an adjustment of cytokine responses away from the Th1 paradigm and toward the Th2 pattern. In vivo data from murine pregnancy support this hypothesis. However, in humans, the Th1/Th2 model appears to be more complex than that in mice, and cytokine expression of mRNA in human decidual tissue does not reflect a clear-cut Th2 bias. The experiments described here were undertaken to determine whether and how trophoblastic cells modulate cytokine expression in activated lymphocytes, and whether there is a trend toward the use of the Th2 pattern in an experimental model of the maternal-fetal interface. We used reverse transcriptase polymerase chain reaction (rtPCR) to detect cytokine mRNA expression in human peripheral blood mononuclear cells cocultivated with human choriocarcinoma JAR cells. We found that although IL-2 (a paradigmatic Th1 cytokine) was significantly down-regulated by JAR cells at the mRNA level, similar decreases were also seen in IL-10, which participates in the Th2 paradigm. We were unable to detect changes in either interferon-gamma (IFN-gamma, a Th1 cytokine) or IL-4 (a Th2 cytokine) mRNA's or in IL-2R expression by fluorescence-activated cell sorting. These studies indicate that human choriocarcinoma JAR cells are capable of modifying cytokines in activated lymphocytes other than those involved in the Th1 paradigm. While it may be useful to view human responses against the background of these patterns established from murine systems, it is reasonable to conclude that human pregnancy may not involve regulation of Th1 immune responses exclusively.

Gas chromatographic determination of chlorothalonil in leaves and roots of Scrophularia and in soil

A gas chromatographic method is described for determination of chlorothalonil residues in leaves and roots of Scrophularia and in soil. Samples were extracted with acetone and cleaned up on a Florisil column. Chlorothalonil residues are chromatographed directly on a glass column of 1.5% OV-17 and 2% QF-1 coated on 80-100 mesh Chromosorb W (HP) support and measured with a 63Ni electron capture detector. Detection limits are 0.001 ppm for leaf, 0.005 ppm for root, and 0.001 ppm for soil.

Erwinia amylovora secretes harpin via a type III pathway and contains a homolog of yopN of Yersinia spp

Type III secretion functions in flagellar biosynthesis and in export of virulence factors from several animal pathogens, and for plant pathogens, it has been shown to be involved in the export of elicitors of the hypersensitive reaction. Typified by the Yop delivery system of Yersinia spp., type III secretion is sec independent and requires multiple components. Sequence analysis of an 11.5-kb region of the hrp gene cluster of Erwinia amylovora containing hrpI, a previously characterized type III gene, revealed a group of eight or more type III genes corresponding to the virB or lcrB (yscN-to-yscU) locus of Yersinia spp. A homolog of another Yop secretion gene, yscD, was found between hrpI and this group downstream. Immediately upstream of hrpI, a homolog of yopN was discovered. yopN is a putative sensor involved in host-cell-contact-triggered expression and transfer of protein, e.g., YopE, to the host cytoplasm. In-frame deletion mutagenesis of one of the type III genes, designated hrcT, was nonpolar and resulted in a Hrp- strain that produced but did not secrete harpin, an elicitor of the hypersensitive reaction that is also required for pathogenesis. Cladistic analysis of the HrpI (herein renamed HrcV) or LcrD protein family revealed two distinct groups for plant pathogens. The Yersinia protein grouped more closely with the plant pathogen homologs than with homologs from other animal pathogens; flagellar biosynthesis proteins grouped distinctly. A possible evolutionary history of type III secretion is presented, and the potential significance of the similarity between the harpin and Yop export systems is discussed, particularly with respect to a potential role for the YopN homolog in pathogenesis of plants.

Demonstration of a heat-stable 120-kilodalton protein of Rickettsia japonica as a spotted fever group-common antigen

Genomic libraries of Rickettsia japonica were cloned into an expression vector lambda gt11. A clone expressing a protein reactive with antiserum against 120-kilodalton (kDa) proteins, a mixture of heat-modifiable and heat-stable polypeptides, was selected and designated as lambda Rj120-1. The expressed protein has a molecular mass of 180 kDa. Western immunoblotting demonstrated that the expressed protein was a fusion protein with beta-galactosidase. The antiserum against 120-kDa proteins was absorbed by the induced lysogen, resulting in the removal of reactivity to the heat-stable 120-kDa polypeptide. The antiserum against the expressed protein reacted with heat-stable 120- to 130-kDa polypeptides of spotted fever group (SFG) rickettsiae in addition to R. japonica. The findings indicated that the protein expressed from the cloned gene of R. japonica possessed the antigenicity group-common to SFG rickettsiae. Primers designed from the gene coding for R. conorii heat-stable 120-kDa protein (Schuenke, K.W., and Walker, D.H., Infect. Immun. 62: 904-909, 1994) and lambda gt11 lacZ gene amplified the lambda Rj120-1 DNA by the polymerase chain reaction (PCR). Analysis of restriction fragment length polymorphism (RFLP) of the PCR-amplified products revealed that the cloned DNA corresponds to a portion of the gene coding for the heat-stable 120-kDa protein of R. conorii with 2,519 nucleotides beginning at nucleotide 190 of the open reading frame. RFLP demonstrated that the cloned gene was highly homologous to the corresponding gene of R. conorii.

Evaluation of the redox tolerance index on hepatic energy reserve of hepatitis B patients

OBJECTIVE

To detect the redox tolerance index (RTI) for hepatic energy reserve.

PATIENTS AND METHODS

27 patients with chronic active hepatitis B (CAH) and 34 patients with post-hepatitis B liver cirrhosis (LC) were studied.

RESULTS

The RTI was significantly lower in CAH and LC cases than in normal controls (P < 0.01). There was no difference between CAH and LC. The RTI of decompensated LC was significantly lower than that of the compensated LC (P < 0.05), indicating that there was no correlation between RTI and the parameters of routine liver functions.

CONCLUSION

It is suggested that the RTI based on redox theory is effective and accurate in predicting hepatic energy reserve.

[Ion-selective microelectrodes: principle and application of in vivo measurements of ionic concentrations in cochlear endolymph]

OBJECTIVE

To introduce the method of making neutral carrier ion-selective microelectrode and use it for in vivo measurement of ionic concentrations in cochloear endolymph.

METHODS

GG-17 glass capillaries with 1.85 mm O.D. were rinsed extensively and dried in an oven. Two capillaries were parallelly connected and pulled with microelectrode puller to make a double-barreled micropipette. One barrel was back-filled with ion exchanger and internal reference solution, which served as ionic potential electrode, while the other barrel filled with 150 mmol/L KCL as reference electrode. Each barrel of microelectrode was connected to differential electrometer via Ag-AgCl wire and output was recorded on a three-channel recorder. Every ion-selective microelectrode was calibrated in a series of standard solutions to determine the required characteristics. Twenty healthy guinea pigs with normal hearing were anesthetized and were artificially respired through the tracheal canal after the intramuscular injection of suxamethonium chloride. The tympanic bulla was exposed and a double-barreled ion-selective electrode was inserted into the scala media through the round window and basilar membrane. The ionic potentials and endocochlear potentials (EP) were simultaneously recorded from the basal turn of the cochlea. Ionic concentrations were then calculated by Nicolsky-Eisenman equation.

RESULTS

The concentrations of potassium, sodium and calcium ions in the cochlear endolymph were 146.3 +/- 11.8 mmol/L, 0.36 +/- 0.22 mmol/L and 16.2 +/- 5.7 micromol/L, respectively.

CONCLUSIONS

The neutral carrier ion-selective microelectrode made with the above method is reliable and therefore can be used for accurately measuring the ionic concentrations of microenvironment in vivo continuously and transiently.

Sequestration of inhaled particulate antigens by lung phagocytes. A mechanism for the effective inhibition of pulmonary cell-mediated immunity

Dendritic cells (DCs) have emerged as the dominant antigen-presenting cells (APCs) of the lung, playing a vital role in the induction of cell-mediated immunity to inhaled antigens. We have previously demonstrated that an airway challenge with the soluble antigen hen egg lysozyme yields rapid acquisition of specific antigen-presenting cell activity by purified pulmonary DCs and a cell-mediated immune response in the lung upon secondary challenge. To examine how a particulate antigen leads to a cell-mediated response in vivo, graded concentrations of heat-killed Listeria (HKL) were injected intratracheally into Lewis rats. The bacteria were rapidly ingested by lung macrophages and polymorphonuclear leukocytes. The ability of purified pulmonary DCs pulsed in vivo by an airway challenge with HKL to subsequently stimulate HKL-specific responses ex vivo showed a threshold response, requiring a dose in excess of 10(9) organisms/rat. By contrast, all dosages of HKL yielded specific sensitization of lymphocytes in the draining bilar nodes. Pulmonary DCs purified from rats after a secondary in vivo airway challenge with HKL at day 14 were ineffective antigen-presenting cells except at high dosages of antigen. The generation of cell-mediated pulmonary inflammation paralleled the antigen-presenting cell activity of pulmonary DCs and was observed only at high antigen dosages. Hen egg lysozyme immobilized onto polystyrene beads and injected intratracheally yielded comparable results to those observed with HKL. We suggest that a pulmonary cellular immune response is generated to an inhaled particulate antigen when the protective phagocytic capacities of the lung are exceeded and antigen is able to interact directly with interstitial DCs. The diversion of particulate antigens by pulmonary phagocytes may help to limit undesirable pulmonary inflammation while allowing the generation of antigen-specific immune lymphocytes in vivo.

[Histopathological and immunohistochemical studies on gliosarcoma]

Immunohistochemical staining of 5 gliosarcomas was performed. Neoplastic glial component stained positive by GFAP. Endothelial cells lining the lumina of glomeruloid vascular structures stained positively with both UEA-1 and FVIII/RAg antibodies. Mesenchymal cells of sarcomatous areas stained positively with SMSA antibody and presence of PDGFR. The staining results demonstrate that the sarcomatous component of gliosarcoma is of smooth muscle origin and suggest that the vascular smooth muscle hyperplasia is related to PDGF.

Nitrite, N-nitroso compounds, and other analytes in physiological fluids in relation to precancerous gastric lesions

Levels of gastric juice nitrite, several urinary N-nitroso compounds, and other analytes were examined among nearly 600 residents in an area of Shandong, China, where precancerous gastric lesions are common and rates of stomach cancer are among the world's highest. Gastric juice nitrite levels were considerably higher among those with gastric juice pH values above 2.4 versus below 2.4. Nitrite was detected more often and at higher levels among persons with later stage gastric lesions, especially when gastric pH was high. Of those with intestinal metaplasia, 17.5% had detectable levels of gastric nitrite, while this analyte was detected in only 7.2% of those with less advanced lesions. Relative to those with undetectable nitrite, the odds of intestinal metaplasia increased from 1.5 (95% confidence interval = 0.6-4.1) to 4.1 (95% confidence interval = 1.8-9.3) among those with low and high nitrite concentrations, respectively. Urinary acetaldehyde and formaldehyde levels also tended to be higher among those with more advanced pathology, particularly dysplasia. However, urinary excretion levels of total N-nitroso compounds and several nitrosamino acids differed little among those with chronic atrophic gastritis and intestinal metaplasia and dysplasia, consistent with findings from recent studies in the United Kingdom, France, and Colombia. The data from this high-risk population suggest that elevated levels of gastric nitrite, especially in a high pH environment, are associated with advanced precancerous gastric lesions, although specific N-nitroso compounds were not implicated.

[Enzyme kinetic studies on the in vitro metabolism of omeprazole by Chinese human liver microsomes]

In the present study, a specific and reliable method was developed for the determination of omeprazole and its two major metabolites, hydroxyomeprazole (OH-OPZ) and omeprazole sulfone (OPZ-SFN) in Chinese adult human liver microsome by reversed phase HPLC assay. Formation of these metabolites is linear for at least 60 min and between 0.25 and 1 mg.ml-1 of microsomal protein. The enzyme kinetic analysis of the reaction revealed that the hydroxylation Vmax and K(m) obtained with the human liver microsomal preparation were 42.9 nmol.min-1.(mg protein)-1 and 6.49 mumol.L-1, respectively. The maximum formation rates of OPZ-SFN (Vmax) was 6.63 nmol.min-1.(mg protein)-1, with a K(m) value of 11.8 mumol.L-1. A number of compounds were tested for their ability to inhibit OPZ metabolism. Our results showed that mephenytoin, diazepam and nordiazepam are competitive inhibitors and papaverine is an uncompetitive inhibitor of OPZ hydroxylation. These studies suggest that the same isozyme metabolising MP, DZ and NDZ (may be P450 2C or P450 3A) may be involved in the hydroxylation of OPZ. Moreover, the compounds tested also have some effects on the formation of OPZ-SFN in vitro with Chinese human liver microsomes.

Lysis of adult ventricular myocytes by cells infiltrating rejecting murine cardiac allografts

BACKGROUND

Immunologic mechanisms that mediate myocardial cell injury during rejection are not fully understood. We therefore investigated whether cells that infiltrate rejecting cardiac allografts are capable of directly injuring myocytes and whether this injury resembles that produced by cytotoxic T lymphocytes (CTLs) that are generated in a mixed lymphocyte reaction (MLR).

METHODS AND RESULTS

Heart-infiltrating cells (HICs) were isolated from murine heterotopic BALB/c cardiac allografts undergoing rejection 6 to 8 days after transplantation into C57BL/6 mice. An in vitro model system of cultured adult murine ventricular myocytes was developed to facilitate investigation of cell-mediated myocyte injury. Isolated adult myocytes were incubated with either HICs or MLR effector cells, and myocyte death was quantified by counting the number of rod-shaped myocytes excluding trypan blue. The frequency of donor-reactive CTLs was similar in the HIC and MLR populations, as assessed by limiting dilution analysis. However, HICs were less efficient at killing donor-strain myocytes than were MLR cells. CTL-mediated cell lysis occurred by 6 hours, whereas myocyte injury produced by HICs was more gradual, with considerable cytotoxicity occurring between 12 and 24 hours. Furthermore, whereas MLR cells lysed only donor-strain myocytes, HIC lysed donor, third-party, and syngeneic myocytes. Treatment of MLR cells and HICs with anti-CD8 antibody plus complement produced a much greater inhibition of MLR cytotoxicity than of HIC cytotoxicity.

CONCLUSIONS

These data demonstrate that only a small component of myocyte injury mediated by allograft-infiltrating cells can be ascribed to CTLs within the infiltrating cell population. These findings suggest that cell types associated with a delayed-type hypersensitivity response, as well as CTLs, cause myocyte injury during cardiac rejection.

[Preoperative intraluminal 5-FU osmosis chemotherapy as an adjuvant to radical resection for rectal cancer]

Patients with rectal cancer of stage dukes B and C were randomized into two groups. In osmosis chemotherapy group 86 patients were treated by radical resection plus adjuvent preoperative intraluminal 5-FU osmosis chemotherapy at the area of tumor. In control group 74 patients were treated by radical resection alone. There were high concentration of 5-FU in the cancer, mucosa and lymph node around the cancer and mesenterica inferior venae, and the lower in a round venae. After the chemotherapy the symptoms were improved without side-effects, the II-III grade at pathological change was 83%, the cancer regression more than 50 was 38%. Compared the two groups osmosis chemotherapy raised 14% at radical resection and reduced 22%, 11%, 22% at local recurrence and metastasis of lymph nodes and liver. The 3-, 5-year survival rates (81.1%, 69.6%) were higher than 19.2%, 26.7% in the control group.

Preservation of global cardiac function in the rabbit following protracted ischemia/reperfusion using monophosphoryl lipid A (MLA)

Monophosphoryl lipid A (MLA), a derivative of the minimal substructure of lipopolysaccharide (lipid A) possesses immunomodulatory activity of the parent lipid A yet enjoys reduced toxicity. It has previously been reported that pretreatment with MLA reduces myocardial infarct size and stunning in dogs following ischemia and reperfusion. The aim of this study was to evaluate the ability of monophosphoryl lipid A (MLA) to preserve global cardiac function and peripheral hemodynamics in a rabbit model of prolonged regional ischemia (90 min), and reperfusion (6 h). An evaluation of potential mechanisms by which MLA may preserve cardiac function was also undertaken. Single dose pretreatment with MLA (35 micrograms/kg i.v.) 24 h prior to ischemia resulted in significant improvement in left ventricular developed pressure, dP/dt, rate-pressure product and mean arterial pressure during reperfusion (P < 0.05 v control). Although in this model of prolonged ischemia MLA pretreatment did not reduce infarct size (54.5 +/- 11.4% in control v 63.3 +/- 8.3% in MLA, P = N.S.), evaluation of myocardial adenylate and adenosine catabolite pools at the end of ischemia indicated a preservation of ATP and ADP and a decreased production of downstream adenosine catabolites including inosine, xanthine and uric acid. Adenosine kinase, but not 5'-nucleotidase (5'-NTase) or adenosine deaminase activity determined following reperfusion was 76% and 60% higher (P < 0.05) in non-risk and post-ischemic myocardium of MLA pretreated rabbits compared with controls. Although there was a trend toward lower tissue myeloperoxidase activity in post-ischemic myocardium from treated rabbits, the results were not significantly different from control animals. These results suggest that a 24-h pretreatment with MLA, without further treatment during ischemia or reperfusion was associated with: (1) preservation of global myocardial function during reperfusion; (2) preservation of myocardial high energy adenylates and reduced formation of adenosine catabolites during ischemia; (3) elevated myocardial adenosine kinase activity. Increased recycling of adenosine to phosphorylated nucleotides may result from MLA's affect on adenosine kinase, which could explain the drugs effect on adenylate and adenosine metabolite pools.