Characterization of the Yersinia pestis Yfu ABC inorganic iron transport system

In Yersinia pestis, the causative agent of plague, two inorganic iron transport systems have been partially characterized. The yersiniabactin (Ybt) system is a siderophore-dependent transport system required for full virulence. Yfe is an ABC transport system that accumulates both iron and manganese. We have identified and cloned a Y. pestis yfuABC operon. The YfuABC system is a member of the cluster of bacterial ABC iron transporters that include Sfu of Serratia, Hit of Haemophilus, and Yfu of Yersinia enterocolitica. The Y. pestis KIM6+ system is most homologous to that in Y. enterocolitica, showing identities of 84% for YfuA (periplasmic binding protein), 87% for YfuB (inner membrane permease), and 75% for YfuC (ATP hydrolase). We constructed a yfuABC promoter-lacZ fusion to examine regulation of transcription. This promoter contains a potential Fur binding sequence and is iron and Fur regulated. Significant expression from the yfuABC promoter occurred during iron-deficient growth conditions. In vitro transcription and translation of a recombinant plasmid encoding yfuABC indicates that YfuABC proteins are expressed. Escherichia coli 1017 (an enterobactin-deficient mutant) carrying this plasmid was able to grow in an iron-restrictive complex medium. We constructed a deletion encompassing the yfuABC promoter and most of yfuA. This mutation was introduced into strains with mutations in Ybt, Yfe, or both systems to examine the role of Yfu in iron acquisition in Y. pestis. Growth of the yfu mutants in a deferrated, defined medium (PMH2) at 26 and 37 degrees C failed to identify a growth or iron transport defect due to the yfu mutation. Fifty percent lethal dose studies in mice did not demonstrate a role for the Yfu system in mammalian virulence.

[A study on the relations of soluble interleukin-2 receptor and CD+25 cell with acute graft-versus-host disease]

OBJECTIVE

Acute graft-versus-host disease (aGVHD) is one of the major complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Prediction of human aGVHD may be of help in its diagnosis and therapy.

METHODS

22 patients undergoing HSCT were included in this study. After transplantation, serum concentrations of interleukin-6, interleukin-8, tumor necrosis factor-alpha, interferon-gamma and sIL-2R were measured periodically by using enzyme-linked immunosorbent assay. Immune reconstitution of CD(+)(3), CD(+)(4), CD(+)(8), CD(+)(25) and CD(+)(69) cells were analyzed with flow cytometry.

RESULTS

All the patients achieved engraftment. 6 patients developed grade I GVHD and 4 patients developed grade III-IV GVHD. Patients with aGVHD demonstrated significantly higher sIL-2R levels than those without. The peak levels of grade III-IV GVHD were (420.3 +/- 59.8) U/L,and the peak levels of grade I GVHD were (221.5 +/- 38.8) U/L. The increase of sIL-2R level in serum preceded the clinical signs of aGVHD. The maximum levels of sIL-2R correlated significantly with the severity of aGVHD. The increase of CD(+)(25) cells was in accordance with that of sIL-2R.

CONCLUSIONS

Analysis of serum cytokines and immune reconstitution after HSCT may provide predictive value for aGVHD.

Novel lysophospholipase A secreted by Legionella pneumophila

We show that Legionella pneumophila possesses lysophospholipase A activity, which releases fatty acids from lysophosphatidylcholine. The NH2-terminal sequence of the enzyme contained FGDSLS, corresponding to a catalytic domain in a recently described group of lipolytic enzymes. Culture supernatants of a L. pneumophila pilD mutant lost the ability to cleave lysophosphatidylcholine.

[Types of chemokines expressed by murine dendritic cell line]

OBJECTIVE

To analyze the types of chemokines expressed in murine medullary thymic dendritic cell line (MTDC).

METHODS

A MTDC line was established. RT-PCR was used to amplify the cDNA fragments of SDF-1, IP-10, KC, MCP-1, and lymphotactin expressed by MTDC. Nucleotide sequencing and dot blotting analysis were performed to confirm their existence.

RESULTS

Five cDNA fragments SDF-1, KC, IP-10, MCP-1, and lymphotactin, were amplified from MTDC. The existence of SDF-1, KC, and lymphotactin was confirmed by nucleotide wequencing, and that of IP-10, MCP-1, and lymphotactin was confirmed by dot blotting. The supernatant of MTDC exhibited chemoattractant activities to CD(4)(-) approximately CD(8)(-) thymocytes with a chemotactic index (CI) of 3.4.

CONCLUSION

There is a lot of chemokines in MTDC, including C-X-C subfamily (SDF-1, KC, and IP-10) CC subfamily (MCP-1), and C subfamily (lymphotactin). The suparnatant of MTDC has moderately chemotactic activities to CD(4)(-) approximately CD(8)(-) thymocytes, consistent with the biological function of SDF-1.

Progress in the research and demonstration of Everglades periphyton-based stormwater treatment areas

The South Florida Water Management District (District) is conducting research focused on potential advanced treatment technologies to support reduction of phosphorus (P) loads in surface water entering the remaining Everglades. Periphyton-based stormwater treatment areas (PSTA) are one of the advanced treatment technologies being researched by the District. This detailed research and demonstration project is being conducted in two phases. Basic research in field-based mesocosm experiments was conducted during the first phase within the District's Everglades Nutrient Removal Project (ENR). Studies were conducted in 24 portable PSTA mesocosms and three of the south ENR test cells. Phase 1 studies addressed the effects of system substrate (shellrock, organic peat, or sand), water depth, hydraulic loading rate, vegetation presence, depth:width ratio, and inhibition of algal growth on total phosphorus removal performance of the PSTA mesocosms. A second phase of research is currently under way, during which PSTA feasibility will be evaluated further in four field-scale constructed mesocosms totaling about 2 ha, and follow up studies within the ENR test cells and portable mesocosms will be conducted to further investigate the effects of other inorganic substrates, shallow water depth, and velocity on treatment performance. Phase 1 monitoring has determined that periphyton-dominated communities can be established in constructed wetlands within 5 months. The algal component of these periphyton plant communities is characteristic of natural Everglades periphyton. High macrophyte densities resulted from use of peat soils in PSTA mesocosms, while shellrock and sand soils promoted more desirable sparse macrophyte stands. P removal rates under the conditions of this research were relatively high considering the low influent total P concentrations tested (average 23 microg/L). PSTA mesocosms on shellrock soils were able to attain long-term average outflow total P concentrations as low as 11 microg/L. The maximum one-parameter TP first-order removal rate constant (k1) measured was 27 m/y. Minimum attainable outflow total P concentrations and mass removals appear to be the result of a balance between internal P loading from antecedent soils, uptake and burial processes in new sediments, and rainfall inputs. A different soil type (limerock) will be tested for effectiveness during Phase 2. Selected existing treatments will also be continued to look for trends over a second growing season.

[Melanoma antigen-3 expression in human hepatocellular carcinoma]

OBJECTIVE

To investigate the expression of melanoma antigen-3 (MAGE-3) mRNA in human hepatocellular carcinoma (HCC) and probe into the theoretical feasibility that MAGE-3 antigens can be developed as a new peptide vaccine for immunotherapy in HCC patients.

METHODS

The expression of MAGE-3 mRNA in HCC tissues and the adjacent non-HCC liver tissues was studied using RT-PCR in 45 HCC patients. The results were compared with those of 16 cirrhotic patients and 12 patients whose liver tissues were pathologically normal. MAGE-3 mRNA positive PCR products were DNA sequenced in 3 HCC patients. The sequenced fragments of MAGE-3 cDNA were used as template by which a [alpha(32)P] labeled probe was synthesized and employed for Southern blot analysis. HLA class I-A and -B typing of 43 HCC patients were assayed by ELISA.

RESULTS

Of the 45 HCC samples, 35 (78%) expressed MAGE-3 mRNA and six HCC adjacent tissues were also positive in MAGE-3 expression. Pathological examination showed cellular heteromorphism in these adjacent tissues. The non-HCC liver tissues from cirrhosis and normal liver samples were not MAGE-3 mRNA detectable. The DNA sequence confirmed that the target gene fragment in all of the 3 samples of PCR products was MAGE-3 cDNA. Southern blotting result confirmed that of RT-PCR assay. In HCC patients, the predominant types of HLA were A(2) (53.5%), A(11) (25.6%), A(24) (20.9%), A(33) (20.9%), B(13) (28.3%), and B(35) (23.2%). MAGE-3 mRNA expression in HCC showed no correlation with the level of serum AFP and the size of the tumor.

CONCLUSIONS

MAGE-3 mRNA is expressed at a high percentage of HCC samples. This tumor rejection antigen may be used as peptide vaccine for immunotherapy of HCC patients. The phenomena that some non-HCC adjacent tissues with heteromorphism can express MAGE-3 like their paired HCC tissues indicate that the expression of MAGE-3 may be an indicator in the early stage of carcinogenesis of liver tissues.

A monoclonal antibody to the DEC-205 endocytosis receptor on human dendritic cells

DEC-205 is a multilectin receptor for adsorptive endocytosis, expressed in mouse dendritic cells (DC) and some epithelia. DEC-205 is homologous to the macrophage mannose receptor (MMR). A cDNA for murine DEC-205 was used to identify 3 overlapping human DEC-205 clones from a lymphocyte library. The human homologue is a transmembrane protein of 1722 aminoacids with 10 externally disposed C-type lectin domains having 77% identity to the mouse counterpart. The NH(2) terminal cysteine-rich and fibronectin type II domains were expressed and used to immunize mice. A hybridoma, MG38, which specifically recognized the immunogen was obtained from a DEC-205 knockout mouse. The antibody precipitated a 205 kD protein from metabolically labeled, monocyte-derived DCs. MG38 labeled mature monocyte-derived DCs but showed weak or no labeling of other peripheral blood mononuclear cells. In tissue sections, MG38 identified DEC-205 on thymic cortical epithelium and DCs in the thymic medulla and tonsillar T cell areas. In contrast, an anti-MMR antibody stained DEC-205 negative, macrophages in the thymus cortex, the trabeculae of the thymus and tonsil, as well as efferent lymphatics in the tonsil. Therefore, the MG38 anti-DEC-205 antibody is useful for identifying DCs and reveals clear differences in sites where MMR and DEC-205 are expressed in lymphoid tissues.

New evidence for an extra-hepatic role of N-acetylglucosaminyltransferase III in the progression of diethylnitrosamine-induced liver tumors in mice

N-acetylglucosaminyltransferase III (GlcNAc-TIII) is encoded by the Mgat3 gene and catalyzes the addition of the bisecting GlcNAc to the core of N-glycans. Mice lacking GlcNAc-TIII due to the insertion mutation Mgat3tmlPst (termed Mgat3neo), exhibit retarded progression of liver tumors induced by diethylnitrosamine (DEN; M. Bhaumik et al, Cancer Res., 58: 2881-2887, 1998). This phenotype seemed to be due to a reduction, in activity or amount, of a circulating glycoprotein(s) that enhances DEN-induced liver tumor progression. Here, we provide new evidence to support this hypothesis. First, we show that mice with a deletion mutation of the Mgat3 gene coding exon (Mgat3tmlJxm, termed Mgat3delta) also exhibit retarded progression of DEN-induced liver tumors. At 7 months there was a significant decrease in liver weight (approximately 27%; P < 0.01), reflecting reduced tumor burden in Mgat3delta/delta mice. In addition, tumors were generally fewer and smaller, and histological changes were less severe in Mgat3delta/delta livers. Therefore, tumor progression is retarded in mice with two different null mutations in the Mgat3 gene. Second, we show that the development of DEN-induced tumors is unaltered by high levels of GlcNAc-TIII in the liver of transgenic mice. The Mgat3 gene coding exon under the control of the major urinary protein (MUP) promoter was used to generate transgenic mice that express GlcNAc-TIII in liver. Following DEN injection and phenobarbitol treatment, however, no significant differences were observed between MUP/Mgat3 transgenic and control mice in either tumor numbers or liver weight. The combined data provide strong evidence that retarded progression of tumors in mice lacking GlcNAc-TIII is due to the absence of the bisecting GlcNAc residue on N-glycans of a circulating glycoprotein(s) from a tissue other than liver.

DEC-205 as a marker of dendritic cells with regulatory effects on CD8 T cell responses

We have previously reported that a population of lymphoid-related CD8alpha(+) DEC-205(+) dendritic cells (DC) from mouse spleen have 'regulatory' effects on the T cells they activate. CD8 T cells produce IL-2 and give a sustained proliferative response to allogeneic CD8alpha(-) DEC-205(-) splenic DC, but produce little IL-2 and give a limited response to allogeneic CD8(+) DEC-205(+) splenic DC. Although CD8alpha and DEC-205 correlate closely among splenic DC, lymph nodes (LN) include a large population of CD8alpha(low) DEC-205(high) DC. By i.v. transfer of purified thymic early lymphoid precursors into irradiated recipient mice we now demonstrate that these CD8alpha(low) but DEC-205(high) LN DC can be the progeny of a lymphoid precursor population, apparently corresponding to the CD8alpha(high) DEC-205(high) DC progeny of the same precursors in spleen and thymus. By culture of the separated, purified DC with allogeneic CD8 T cells we demonstrate that the CD8alpha(low) DEC-205(high) DC of LN are also functionally equivalent to the CD8alpha(high) DEC-205(high) DC of spleen. Therefore, DEC-205 but not CD8alpha serves to segregate functionally distinct DC types in LN. However, DC isolated from the spleens of genetically manipulated DEC-205(null) mice and separated on the basis of CD8alpha expression have a similar capacity to stimulate CD8 T cells as their heterozygous littermate controls, with the CD8alpha(+) but now DEC-205(null) DC still giving restricted responses. In conclusion, high expression of DEC-205 appears to be a good marker of the lymphoid-related regulatory type of DC, but DEC-205 itself is not responsible for transmitting negative signals to the T cells.

[Expression of heat shock protein 70 in immune response of the guinea pig inner ear]

OBJECTIVE

To explore whether the immune response of the inner ear could induce heat shock protein (hsp) 70 in guinea pig cochlea.

METHODS

A model of autoimmune inner ear disease (AIED) was established by systemically immunizing the guinea pig with the homologous crude inner ear antigen (CIEAg). The immunized cochleae and normal control cochleae were examined for the expression of hsp70 with techniques of immunohistochemistry and in situ hybridization.

RESULTS

In the control animals, the expression of the hsp70-like protein appeared only in the spiral ganglion, whereas in the cochleae with CIEAg immunization, strong expression of the hsp70-like protein and its mRNA appeared in the spiral ganglion as well as in the stria vascularis and the spiral ligament. The hearing thresholds were significantly increased in 10 out of 28 cochleae (35.7%) with CIEAg immunization.

CONCLUSION

The results suggest that the immune response of the inner ear can induce the expression of hsp70 in the guinea pig cochlea.

Isoelectric focusing nonporous RP HPLC: a two-dimensional liquid-phase separation method for mapping of cellular proteins with identification using MALDI-TOF mass spectrometry

A novel two-dimensional liquid-phase separation method was developed that is capable of resolving large numbers of cellular proteins. The proteins are separated by pI using isoelectric focusing in the first dimension and by hydrophobicity using nonporous reversed-phase HPLC in the second dimension (IEF-NP RP HPLC). Proteins were mapped using original software in order to create a protein pattern analogous to that of the 2-D PAGE image. RP HPLC peaks are represented by bands of different intensity in the 2-D image, according to the intensity of the peaks eluting from the HPLC. Each peak was collected as the eluent of the HPLC separation in the liquid phase. The proteins collected were identified using proteolytic enzymes, MALDI-TOF MS and MSFit database searching. Using IEF-NP RP HPLC, approximately 700 bands were resolved in a pI range from 3.2 to 9.5 and 38 different proteins with molecular weights ranging from 12,000 to 75,000 were identified. In comparison to a 2-D gel separation of the same human erythroleukemia cell line lysate, the IEF-NP RP HPLC produced improved resolution of low mass and basic proteins. In addition, the proteins remained in the liquid phase throughout the separation, thus making the entire procedure highly amenable to automation and high throughput. It is demonstrated that IEF-NP RP HPLC provides a viable alternative to the 2-D gel separation method for the screening of protein profiles.

Novel phospholipase A activity secreted by Legionella species

Bacterial phospholipases are regarded as a major virulence factor in infection. In bacteria associated with pneumonia, destruction of lung surfactant and host cell membranes by bacterial phospholipases secreted during infection is thought to contribute to the disease. Phospholipase C (PLC) activity has been described in several Legionella species (W. B. Baine, J. Gen. Microbiol. 134:489-498, 1988; W. B. Baine, J. Gen. Microbiol. 131:1383-1391, 1985). By using detection methods such as thin-layer chromatography and mass spectrometry, PLC activity could not be detected in several strains of Legionella pneumophila. Instead, phospholipid degradation was identified to be caused by a novel PLA activity. We could demonstrate that PLA secretion starts at the mid-exponential-growth phase when bacteria were grown in liquid culture. Several Legionella species secreted different amounts of PLA. Legionella PLA may act as a powerful agent in the mediation of pathogenicity due to destruction of lung surfactant and epithelial cells.

[Parasitic metamorphosis development of Lamprotula fibrosa]

The glochidia of Lamprotula fibrosa develop to maturity in the outer gill of female and are expelled to the outside in winter, and then, the mature glochidia are parasitized to the gill of fish host and start the parasitic metamorphosis development. The parasitic period lasts about 4 months. The inner and outer byssuses disappear after parasitizing for 3 days. The foots develop after 35 days. The intestine, adductor muscle, nephridium and gill anlage develop after 90 days. The shells become thick and protrusive. The glochidia become larvae with a size of 253.37 x 273.26 x 179.96 microns in the next spring, then leave the gill of fish host, and start their independent life.

Discernment of the sensitized inner ear by peripheral immunocompetent lymphocytes

OBJECTIVE

To investigate the role of peripheral immunocompetent lymphocytes during the immune response in the inner ear.

METHODS

Sensitized lymphocytes from peripheral blood, neck lymph nodes and spleen of three groups of donor animals, i.e., group A immunized intradermally with keyhole limpet hemocyanine (KLH) and both inner ears challenged with KLH, group B received only KLH intradermally without inner ear challenge, and group C used as control, were isolated and labelled with 51Cr. The labelled lymphocytes were injected intravenously into the recipients. They were immunized intradermally with right inner ears challenged with KLH. Twenty to 24 h later, the radioactivities in the temporal bones of the recipients were assayed to detect the infiltration of labelled cells.

RESULTS

In groups A and B, the radioactivity in the right temporal bones was higher than that in the left temporal bones (P < 0.05). The highest labelling radioactivity was detected in the right temporal bones of group A. The lowest migration of 51Cr-labelled cells to the inner ear was found in group C. The ratio of radioactivity between right (challenged) and left (unchallenged) inner ears was higher in group A than in groups B and C, with the difference being significant (P < 0.05).

CONCLUSION

The immune reaction in response to antigenic stimulation in the inner ear is immunologically modulated by the peripheral systemic circulation.

[Nerve electrogram study on different degrees injuries of recurrent laryngeal nerve]

OBJECTIVE

To study the display of different degrees injuries of recurrent laryngeal nerve in electroneurogram.

METHOD

We imitated several common types of injuries i.e. stretch, claming, electrocautery and cut in cervial segment of recurrent laryngeal nerve and measured latency and amplitude of the nerve by electroneurography.

RESULT

The normal value of latency was (1.58 +/- 0.14) ms and that of amplitude was (2.53 +/- 0.78) mV; stretch group was (2.43 +/- 0.32) ms and (0.95 +/- 0.23) mV; claming group was (2.99 +/- 0.55) ms and (0.62 +/- 0.22) mV; electrocautery group was (4.85 +/- 1.03) ms and (0.24 +/- 0.15) mV; cut group was infinity ms and 0 mV.

CONCLUSION

Latency correlated directly with the degree of nerve injury. Whereas amplitude correlated inversely with the degree of nerve injury. Stretch injured recurrent laryngeal nerve the least, followed by claming, electrocautery and cut. This method could be used for nerve monitoring during operation and prognostic judgement.

[Rescue and prevention of serious systemic toxicity following local anesthesia to mucous membranes of tetracaine]

Tetracaine remains a popular agent in clinical for the purpose of local anesthesia to mucous membranes. Its potential for systemic absorption and resulting toxicity has been seldom emphasized. One case of fatality from tetracaine pharyngeal local anesthesia for fibro-laryngoscopic procedure is described. The pharmacologic basis, clinical features, rescue and prevention for systemic toxicity is discussed.

[Determination of IL-6 in serum and perilymph during inner ear immune response]

During secondary inner ear immune responses against keyhole limpet hemocyanin (KLH), to understand the change of interleukin-6 (IL-6) levels in perilymph and serum, IL-6 levels in perilymph and serum were investigated using an immunoassay. No IL-6 levels were detectable at Day 0 in perilymph. The earliest perilymph IL-6 levels were observed after 6 h, peaking at 24 h, and then decreasing gradually. IL-6 level remnants were detected at 7 days in perilymph. In contrast, during this observation period, low IL-6 levels were only detectable in perilymph from control ears, disappearing after 72 h. IL-6 levels don't change in serum. Previous study has identified the endolymphatic sac (ES) lags behind the earlier appearance of intercellular adhesion molecule-1 (ICAM-1) in the spiral modiolar vein and spiral ligament during immune response. The present study not only provides further support for the existence of an inner ear immune response which is regulated by cytokines, but also supports that cytokines controlling expression of adhesion molecules are released probably by cells which located out of ES.

[Pharmcognostial study on the Geranium wilfordii var. glandulosum]

First time has done pharmcognostical research on the Geranium wilfordii Maxim var. glandulosum Z. M. Tan, including microscopic identification, chemical qualitative test and bacteriostatic test.

[Studies on the fine structures of inner ear vessels in guinea pigs]

In order to investigate the characters of inner ear vessels using the microvascular corrosion casting technique and scanning electron microscope the three-dimensional spatial picture of the vessels in cochlear basilar membrane, utriculus, sacculus and three ampullae of guinea pig were observed. It was found that arteriole coils were present in the modiolus ampullae, utriculus and sacculus. The length of arterioles was therefore prolonged and could keep the blood supply in inner ear stable. The possibility of blood coagulation in these segments increased because the blood flow became slower here. Another character was that the capillary networks appeared denser in stria vascularis and central part of the crista, whereas the vessel meshes in basilar membrane of cochlea and in planum semiculatum of ampullae were looser. These findings suggested that the metabolism in stria vascularis and central part of the crista would be more prosperous than that in the basilar membrane and planum semiculatum of ampullae.

[Expression of intercellular adhesion molecule-1 in immune response of the inner ear]

OBJECTIVE

To understand the role of intercellular adhesion molecule-1(ICAM-1) in the immune response of the inner ear.

METHODS

Inner ear immune response was induced in rats by inoculation of key-hole limpet hemocyanine(KLH) into the scala tympani of animals who had been systemically sensitized. Then the expression of ICAM-1 in the inner ear was examined by immunohistochemistry.

RESULTS

ICAM-1 was found in the epithelium of the spiral modiolar vein (SMV) with its collecting venules (CV) as early as 6 hours postchallenge. Expression of ICAM-1 was observed on the epithelium of the endolymphatic sac(ES) and perisaccular region at 12 hours. The intensity of ICAM-1 staining reached a maximum by 24 or 48 hours in these sites of the inner ear. By day 28, most specimens were devoid of significant staining for ICAM-1.

CONCLUSION

The study elucidates the important role of adhesion molecules in extravasation of inflammatory cells from the systemic circulation during an inner ear immune response. It also shows that cytokines controlling expression of adhesion molecules may be released by cells located outside of ES besides those cells in the ES.

[Prognostic value of basal hormone levels on ovarian reserve]

OBJECTIVE

To study the prognostic value of basal hormone levels on ovarian reserve during ovulation induction.

METHODS

Day 2 serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) levels of 112 ovulation induction cycles (60 infertile patients) were measured by radioimmunoassay. The relationship between basal hormone levels and numbers of dominant follicles and pregnancy rates were analysed.

RESULTS

Day 2 serum FSH > or = 15 IU/L predicted a poor response to ovarian stimulation, with fewer dominant follicles and lower pregnancy rate, so was day 2 serum E2 > or = 45 ng/L. Day 2 serum LH level was unrelated to pregnancy rate.

CONCLUSION

Day 2 FSH and E2 levels are useful in prognostic assessment of ovarian reserve.

[Discernment of the sensitized inner ear by peripheral immunocompetent lymphocytes]

OBJECTIVE

To understand the role of peripheral immunocompetent lymphocytes during an immune response in the inner ear.

METHODS

Sensitized lymphocytes from peripheral blood, neck lymph nodes and spleen from three groups of donor animals (group A was immunized intradermally with KLH and both inner ears were challenged with KLH; group B received only KLH intradermally without an inner ear challenge, and groups C were naive animals) were labelled with 51Cr and injected intravenously into recipients (all of which were immunized intradermally with right inner ears challenged with KLH). Twenty to twenty-four hours later, the temporal bones of recipients were assayed for radioactivity to detect the infiltration of labelled cells.

RESULTS

In group A and B, the right temporal bones showed higher radioactivity than the left temporal bones (P < 0.05). The highest labelling was detected in the right temporal bones of group A. The lowest migration of 51Cr-labelled cells to the inner ear was found in group C animals. The highest ratios between right (challenged) and left (unchallenged) were found in group A animals compared with those of group B and group C. The value was significantly higher in group A than in group B and C (P < 0.05).

CONCLUSION

The results showed that the inner ear comes under the immunosurveillance of the peripheral circulation in response to antigenic stimulation.

Expression of intercellular adhesion molecule-1 in immune response of inner ear

To understand the role of intercellular adhesion molecule-1 (ICAM-1) in immune response of the inner ear, inner ear immune response was induced in rats by inoculation of keyhole limpet hemocyanine (KLH) into the scala tympani of the animals who had been systemically sensitized. The expression of ICAM-1 in the inner ear was immunohistochemically examined. ICAM-1 was found in the epithelium of the spiral modiolar vein (SMV) with its collecting venules (CVs) as early as 6 h after challenge. Expression of ICAM-1 was observed on the epithelium of the endolymphatic sac (ES) and perisaccular region at 12 h. The intensity of ICAM-1 staining reached its peak within 24-48 h in these sites of the inner ear. By day 28, most specimens were devoid of appreciable staining for ICAM-1. Our study demonstrates that adhesion molecules play an important role in extravasation of inflammatory cells from the systemic circulation in the process of inner ear immune response. It also shows that cytokines that control expression of adhesion molecules may be released by cells outside ES, besides those cells in the ES.

Cytomegalovirus infection in children's liver tissues

Immunoperoxidase histochemical assay with monoclonal antibody against human cytomaglovirus (HCMV) was used to detect immediate early antigen (IEA) and early antigen (EA) of HCMV infection in liver tissue of 72 pediatric cases (34 autopsies and 38 biopsies). The HCMV antigen was positive in 25% (18/27). Among them, 12 cases were both HCMV-IEA and EA positive; 4 were HCMV-IEA positive and 2 HCMV-EA positive only. Liver HCMV infection rate in neonates, the infants with the age < 1 year and > 1 year was 8.0%, 60.0%, and 14.8%, respectively, indicating that liver HCMV infection occurred at various ages. The liver HCMV infection rate in different diseases was 50.0% in infantile hepatitis syndrome; 70.0% in extrabiliary malformation, and 12.5% in other hepatopathies, suggesting that infantile hepatitis syndrome and extrabiliary malformation were related with HCMV infection in liver tissues.

Involvement of interleukin-2 in analgesia produced by Coriolus versicolor polysaccharide peptides

AIM

To study the role of interleukin-2 (IL-2) and mediobasal hypothalamus (MBH) in analgesia produced by Coriolus versicolor polysaccharide peptide (PSP).

METHODS

The IL-2 antiserum was injected i.c.v. or i.p. and the MBH was destroyed electrolytically.

RESULTS

PSP i.g. 1 g.kg-1.d-1 for 6 d increased the pain threshold in tail stimulation-vocalization test in rats. This PSP-produced analgesia was blocked by i.c.v., but not i.p., IL-2 antiserum and disappeared after electrolytic lesion of MBH.

CONCLUSION

The analgesia produced by PSP is mediated by IL-2 which is activated by PSP and interacts with IL-2 receptors in the MBH.

[Study on determination of composition of complex by multiwavelength R factor method]

The pure spectrum of the complex is obtained by R factor method to eliminate the absorbance of equilibrium concentration of residual reagent. The reagent concentration is determined by multiple linear regression method. As initial concentrations of metal and reagent are changed, and the stable constant is not changed, complex composition and its constant are acquired by means of trial method, in which the input parameters, m and n, are selected. Then the K value is calculated and the minimum value of the total derivation in K is found. By this method, the composition of complex in systems such as Pb-XO, Al-CAS and Zn-PAR are all to be 1:2.

[Application of ultra-short gonadotropin-releasing hormone agonist protocol in controlled ovarian hyperstimulation]

OBJECTIVE

To study the effect of the ultra-short protocol of gonadotropin releasing hormone agonist (GnRH-a) combined with human menopausal gonadotropin (hMG) regimen for ovarian hyperstimulation.

METHODS

Setting clomiphene (CC)/human chronic gonadotropin (hCG) (50 cycles, 31 patients) and CC/hmg/hCG regimens (16 cycles, 16 patients who had failed in CC/hCG) as control groups, the ultra-short GnRH-a/hMG/hCG regimen (15 cycles, 15 patients who had failed in CC alone or CC/hMG regimens) as study group, the number of leading follicles, endometrial thickness, cervical mucus scores and hormone levels on the day of hCG administration, and the pregnancy rates were compared among of these three groups.

RESULTS

There was no premature luteotropic hormone (LH) surge in the ultra-short GnRH-a/hMG/hCG regimen group while there were three cycles in the CC/hMg/hCG group. The LH and progesterone (P) levels of ultra-short GnRH-a/hMG group on the day of hCG administration were lower than those of CC alone and CC/hMG groups. There were more leading follicles, greater endometrial thickness and cervical mucus score in the ultra-short GnRH-a/hMG group than those in CC alone and CC/hMG groups. The pregnancy rates per cycles in the three groups were similar.

CONCLUSION

The ultra-short GnRH-a/hMG regimen is a fairly good ovarian hyperstimulation regimen, especially for poor responders in CC alone or CC/hMG regimens.

Control of immunoglobulin gene rearrangements in developing B cells

The antigen receptor on B lymphocytes is the product of a series of gene rearrangements which ends when a functional receptor gene is assembled. Recent work has shown that the receptor-associated molecules Ig alpha and Ig beta provide the signals that lead to inhibition of further recombination. Furthermore, Ig beta has been implicated in initiating the last step of the recombination reaction.

Counterselection against D mu is mediated through immunoglobulin (Ig)alpha-Igbeta

The pre-B cell receptor is a key checkpoint regulator in developing B cells. Early events that are controlled by the pre-B cell receptor include positive selection for cells express membrane immunoglobulin heavy chains and negative selection against cells expressing truncated immunoglobulins that lack a complete variable region (D mu). Positive selection is known to be mediated by membrane immunoglobulin heavy chains through Ig alpha-Ig beta, whereas the mechanism for counterselection against D mu has not been determined. We have examined the role of the Ig alpha-Ig beta signal transducers in counterselection against D mu using mice that lack Ig beta. We found that D mu expression is not selected against in developing B cells in Ig beta mutant mice. Thus, the molecular mechanism for counterselection against D mu in pre-B cells resembles positive selection in that it requires interaction between mD mu and Ig alpha-Ig beta.

The B-cell-specific transcription coactivator OCA-B/OBF-1/Bob-1 is essential for normal production of immunoglobulin isotypes

OCA-B was initially identified as a B-cell-restricted coactivator that functions with octamer binding transcription factors (Oct-1 and Oct-2) to mediate efficient cell type-specific transcription of immunoglobulin promoters in vitro. Subsequent cloning studies led to identification of the coactivator as a single polypeptide, designated either as OCA-B (ref. 3), OBF-1 (ref. 4) or Bob-1 (ref. 5). OCA-B itself does not bind to DNA directly, but interacts with either Oct-1 or Oct-2 to potentiate transcriptional activation. To determine the biological role of OCA-B, we generated OCA-B-deficient mice by gene targeting. Mice lacking OCA-B undergo normal antigen-independent, B-cell differentiation, including appropriate expression of both immunoglobulin genes and other early B-cell-restricted genes. However, antigen-dependent maturation of B cells is greatly affected. The proliferative response to surface IgM crosslinking is impaired, and there is a severe deficiency in the production of secondary immunoglobulin isotypes including IgG1, IgG2a, IgG2b, IgG3, IgA and IgE in OCA-B-deficient B cells. This defect is not due to a failure of the isotype switching process, but rather to reduced levels of transcription from normally switched immunoglobulin heavy-chain loci. In accord with the defective isotype production, germinal centre formation is absent in these mutant mice.

[Experimental studies on effects of zinc and germanium on immune function and anti-oxidation in mice]

Zinc and germanium concentrations in serum, liver and muscle of mice, T-lymphocyte subgroup proportion, serum superoxide dismutase (SOD) activity and malonodialdehyde (MDA) were determined to study whether there exist synergism or antagonism between zinc and germanium. Results showed there existed, to certain extent, competitive effects of serum zinc and germanium in mice. When concentration of serum zinc increased, that of germanium decreased, or vise versa. There existed certain relationship between zinc and germanium concentrations in serum and those in muscle and liver of mice, and between those and CD3 count and SOD activity. Immune function in mice was influenced and their T-lymphocyte subgroup proportion changed with changes in serum zinc and germanium concentrations. With increased germanium and decreased zinc serum concentrations, CD3 and CD1 counts decreased, CD8 count unchanged, and the ratio of CD1 to CD3 decreased, which showed certain antagonist effects of them as they operated together. But, no antagonism was observed in their anti-oxidant effects, SOD activity increased to varied extent, and the level of MDA decreased.

Regulation of an early developmental checkpoint in the B cell pathway by Ig beta

Many of the cell fate decisions in precursor B cells and more mature B cells are controlled by membrane immunoglobulin (Ig)M heavy chain (mu) and the Ig alpha-Ig beta signal transducers. The role of Ig beta in regulating early B cell development was examined in mice that lack Ig beta (Ig beta-/-). These mice had a complete block in B cell development at the immature CD43+B220+ stage. Immunoglobulin heavy chain diversity (DH) and joining (JH) segments rearranged, but variable (VH) to DJH recombination and immunoglobulin messenger RNA expression were compromised. These experiments define an unexpected, early requirement for Ig(beta) to produce B cells that can complete VDJH recombination.

[Investigation and experimental study on the standards and quality of leech pieces]

It has been confirmed by investigation that Whitmania pigra is the main medicinal breed of leech, and filiform pieces are the best for extraction. The quality of leech processed by 3 different methods has been studied qualitatively and quantitatively in terms of amounts of extraction, TLC, electrophoresis of protein and anti-thrombin action.

[Protective effects of prostacyclin on acute necrotizing pancreatitis and its renal damage in rats]

In a rat model with acute necrotizing pancreatitis (ANP), the administration of exogenous prostacyclin (PGI2) significantly increased the pancreatic and renal blood flow, brought the level of 6-keto-PGF1 alpha to TXB2 in renal vein blood back to normal, reduced the severity of pancreatic and renal histolcagic damage, decreased the mortality, and prolonged survival time. The study showed that exogenous PGI2 can increase pancreatic blood flow in rats with ANP, help to prevent ANP, and protect from renal damage following ANP.

[Involvement of vasopressinergic neurons of paraventricular nucleus in the electroacupuncture-induced inhibition of experimental visceral pain in rats]

It has been demonstrated in animal model of somatic pain that hypothalamic paraventricular nucleus (PVN) participates in acupuncture analgesia, probably by mediation of vasopressin release. The role of PVN in acupuncture analgesia for experimental visceral pain in rats was further investigated in the present study. Experimental results demonstrated that electroacupuncture could inhibit the writhing response, produced by intraperitoneal injection of antimonium potassium tartrate and this inhibitory effect could be enhanced by electrical stimulation of PVN, but decreased by electrolytical lesion of PVN, intracerebroventricular injection of vasopressin antiserum (14 microliters) or the vasopressin antagonist, d(CH2)5Tyr(Me)-AVP (500 ng/5 microliters). Intraperitoneal administration of the latter drug (10 micrograms/kg), however, was ineffective. The above experimental results suggest that vasopressinergic neurons in PVN also participate in the inhibition of visceral pain by electroacupuncture.

Transcription factor AP-2 activates gene expression of HTLV-I

The HTLV-I LTR contains three conserved regulatory elements known as 21 base pair repeats which are required for stimulation of gene expression by the transactivator protein tax. Mutagenesis indicates that the 21 bp repeats can be subdivided into three motifs, A, B and C, each of which influences the level of tax activation. The A site in the 21 bp repeat has strong homology with previously described binding sites for the transcription factor AP-2. We demonstrated that AP-2 mRNA was present in T-lymphocytes and that cellular factors from both non-transformed and transformed T-lymphocytes specifically bound to the consensus motif for AP-2 in each 21 bp. To determine the role of AP-2 in the regulation of the HTLV-I LTR gene expression, we used an AP-2 cDNA in DNA binding and transient expression assays. Gel retardation and methylation interference studies revealed that bacterially produced AP-2 bound specifically and with high affinity to all three 21 bp repeats, and that it required the core sequence AGGC for specific binding. Binding of AP-2 prevented the subsequent binding of members of the CREB/ATF family to an adjacent regulatory motif in the 21 bp repeat. Transfection of an AP-2 expression construct into T-lymphocytes activated gene expression from the HTLV-I LTR. At least two 21 bp repeats were required for high levels of AP-2 activation and mutagenesis of the AP-2 consensus binding sequences in the 21 bp repeats eliminate this activation.(ABSTRACT TRUNCATED AT 250 WORDS)