Immunity to Chlamydia trachomatis mouse pneumonitis induced by vaccination with live organisms correlates with early granulocyte-macrophage colony-stimulating factor and interleukin-12 production and with dendritic cell-like maturation

As is true for other intracellular pathogens, immunization with live Chlamydia trachomatis generally induces stronger protective immunity than does immunization with inactivated organism. To investigate the basis for such a difference, we studied immune responses in BALB/c mice immunized with viable or UV-killed C. trachomatis mouse pneumonitis (MoPn). Strong, acquired resistance to C. trachomatis infection was elicited by immunization with viable but not dead organisms. Immunization with viable organisms induced high levels of antigen-specific delayed-type hypersensitivity (DTH), gamma interferon production, and immunoglobulin A (IgA) responses. Immunization with inactivated MoPn mainly induced interleukin-10 (IL-10) production and IgG1 antibody without IgA or DTH responses. Analysis of local early cytokine and cellular events at days 3, 5, and 7 after peritoneal cavity immunization showed that high levels of granulocyte-macrophage colony-stimulating factor and IL-12 were detected with viable but not inactivated organisms. Furthermore, enrichment of a dendritic cell (DC)-like population was detected in the peritoneal cavity only among mice immunized with viable organisms. The results suggest that early differences in inducing proinflammatory cytokines and activation and differentiation of DCs may be the key mechanism underlying the difference between viable and inactivated organisms in inducing active immunity to C. trachomatis infection.

Interleukin-12 production is required for chlamydial antigen-pulsed dendritic cells to induce protection against live Chlamydia trachomatis infection

Immunization with dendritic cells pulsed ex vivo with antigens has been successfully used to elicit primary antigen-specific immune responses. We report that mouse bone marrow-derived dendritic cells pulsed with inactivated chlamydial organisms induced strong protection against live chlamydial infection in a mouse lung infection model. Either the dendritic cells or chlamydial organisms alone or macrophages similarly pulsed with chlamydial organisms failed to induce any significant protection. These observations suggest that dendritic cells can efficiently process and present chlamydial antigens to naive T cells in vivo. Mice immunized with the chlamydia-pulsed dendritic cells preferentially developed a Th1 cell-dominant response while mice immunized with the other immunogens did not, suggesting a correlation between a Th1 cell-dominant response and protection against chlamydial infection. We further found that dendritic cells produced a large amount of interleukin 12 (IL-12) upon ex vivo pulsing with inactivated chlamydial organisms, which may allow the dendritic cells to direct a Th1 cell-dominant response. Dendritic cells from mice deficient in the IL-12 p40 gene failed to produce IL-12 after a similar ex vivo pulse with chlamydial organisms, and more importantly, immunization with these dendritic cells failed to induce a Th1 cell-dominant response and did not induce strong protection against chlamydial infection. Thus, the ability of dendritic cells to efficiently process and present chlamydial antigens and to produce IL-12 upon chlamydial-organism stimulation are both required for the induction of protection against chlamydial infection. This information may be useful for the further design of effective chlamydial vaccines.

Calcineurin B- and calmodulin-binding preferences identified with phage-displayed peptide libraries

Calcineurin B (CnB) and calmodulin (CaM) are two structurally similar but functionally distinct 'EF-hand' Ca2+-binding proteins. CnB is the regulatory subunit of the CaM-stimulated protein phosphatase, calcineurin. CaM is a unique multifunctional protein that interacts with and modulates the activity of many target proteins. CnB and CaM are both required for the full activation of the phosphatase activity of calcineurin and are not interchangeable. The two proteins recognize distinct binding sites on calcineurin A subunit (CnA) and perform different functions. Phage-displayed peptide libraries (pIII and pVIII libraries) were screened with CnB and CaM to isolate peptides that could then be compared to determine if there were binding preferences of the two proteins. The Ca2+-dependent binding of phage-displayed peptides to CnB and CaM is specifically blocked by synthetic peptides derived from the CnB-binding domain of CnA and the CaM-binding domain of myosin light chain kinase respectively. Both CnB- and CaM-binding peptides have a high content of tryptophan and leucine, but CnB-binding peptides are more hydrophobic than CaM-binding peptides. CnB-binding peptides are negatively charged with clusters of hydrophobic residues rich in phenylalanine, whereas the CaM-binding peptides are positively charged and often contain an Arg/Lys-Trp motif. The binding preferences identified with peptide libraries are consistent with the features of the CnB-binding domains of all CnA isoforms and the CaM-binding domains of CaM targets.

The atherogenic effects of chlamydia are dependent on serum cholesterol and specific to Chlamydia pneumoniae

Epidemiological investigations have linked Chlamydia pneumoniae infection to atherosclerosis. It is not clear, however, whether C. pneumoniae infection plays a causal role in the development of atherosclerosis. Mice with low-density lipoprotein receptor deficiency were induced to develop atherosclerotic lesions in aorta with a cholesterol-enriched diet that increased serum cholesterol by two- to threefold. Using this mouse model, we found that the chlamydial infection alone with either the C. pneumoniae AR39 or the C. trachomatis MoPn strain failed to induce any significant atherosclerotic lesions in aorta over a period of nine months. However, in the presence of a high-cholesterol diet, infection with the C. pneumoniae AR39 strain significantly exacerbated the hypercholesterolemia-induced atherosclerosis, demonstrating that a hypercholesterolemic condition is required for the C. pneumoniae to aggravate the development of atherosclerosis. Although both AR39 and MoPn antigens were detected in aorta of mice infected with the corresponding strains, only mice infected with the C. pneumoniae strain AR39 displayed enhanced atherosclerotic lesions, suggesting that the C. pneumoniae species may possess a unique atherogenic property. This study may provide a model for further understanding the mechanisms of C. pneumoniae atherogenesis and evaluating chlamydial intervention strategies for preventing the advancement of atherosclerotic lesions enhanced by C. pneumoniae infection.

[An experimental study on bone potentials at fracture site with axial interfragmental gradient compression]

OBJECTIVE

To evaluate the mechanism of stress generated potentials in compressive fixation leading to the primary healing.

METHODS

Eighteen fresh sheep tibiae were divided equally into three groups, and all specimen were fractured artificially and imposed "prestressing" at fracture sites with tension device and plate, meanwhile stainless wire tension band was used in the place opposite to plate. The interfragmental pressure was exerted when applied plates, which were 98.62 +/- 19.74 N, 137.93 +/- 8.13 N and 169.20 +/- 11.33 N. Bone potentials at fracture sites were recorded with reference to the potential measurement system by Friedenberg and Brighton (1966).

RESULTS

There was no significant statistical difference in bone potentials when made comparison between before and after compression fixation in each group and among groups of different axial interfragmental gradient compressions.

CONCLUSION

The mechanism of stress generated potentials may not exist in primary healing with compressive fixation.

Contribution of the absence of aspartic acid at position 57 of the HLA-DQ beta chain to predisposition to insulin-dependent diabetes mellitus in a southern Chinese population

OBJECTIVE

To investigate the association of the absence or presence of aspartic acid at position 57 of the HLA-DQ beta chain (NA or A) with susceptibility or resistance to insulin-dependent diabetes mellitus (IDDM) in a Southern Chinese population.

METHODS

Sixty-nine IDDM patients and 47 healthy controls in a Southern Chinese population were HLA-DQB1 genotyped by one-step sequence specific polymerase chain reaction (ssPCR).

RESULTS

The frequencies of NA and A were 64.5% and 35.5% in the IDDM patients, and 40.4% and 59.6% in the control subjects respectively (RR for NA was 2.68, P < 0.01). The frequencies of NA/NA, NA/A and A/A phenotypes were 47.8%, 33.3% and 18.8% in the IDDM patients, and 31.9%, 17.0% and 51.1% in the controls respectively (P < 0.01). The frequency of A/A phenotype was significantly lower in the IDDM patients than in the control subjects (RR = 0.22, P < 0.01). DQB1* 0302 and DQB1* 0201 were more frequent in IDDM patients than in control subjects. The younger the age of IDDM onset, the higher the allele frequencies of DQB1* 0201 and DQB1* 0302.

CONCLUSION

The present study suggests that the NA confers the susceptibility to IDDM, while the A confers the protection against IDDM in patients of Southern Chinese origin. These associations are more clearcut in childhood-onset IDDM patients.

Protective effect of the angiotensin-converting enzyme inhibitor perindopril on diabetic glomerulopathy in streptozotocin-induced diabetic rats

OBJECTIVES

To evaluate the protective effect of the angiotensin-converting enzyme inhibitor perindopril on diabetic glomerulopathy in rats with experimentally induced diabetes and explore its possible mechanisms.

METHODS

Ninety-two adult male Wistar rats were randomly allocated into diabetes mellitus (DM), diabetes mellitus + perindopril (DMP) and control (C) groups. According to the duration of diabetes or observation (1, 3, 6 months), each group was randomly subdivided into DM1, DM3, DM6; DMP1, DMP3, DMP6; and C1, C3, C6 groups. Diabetes was induced by intraperitoneal injection of streptozotocin. The rats in the DMP groups received perindopril 1 mg.kg-1.d-1, through gastric intubation. Urinary protein excretion rate was determined by the method of Coomassie brilliant blue. Plasma renin activity, renal tissue renin activity, and plasma and renal tissue angiotensin II concentration were assayed by radioimmunoassay (RIA). Renal tissue total RNA was extracted by the Chomezymskis AGPC method. Renal angiotensinogen mRNA expression level was assessed by slot blot hybridization using a full length rat angiotensinogen cDNA probe labelled with 32P-dCTP and a random primer.

RESULTS

There was increased activity of the renin angiotensin system in diabetic rats. Perindopril decreased proteinuria and delayed the progression of glomerular basement membrane thickening. However, it did not reduce the expansion of the mesangial matrix (P < 0.05). Renin activity increased and angiotensin II concentration decreased significantly in both plasma and renal tissue in diabetes + perindopril groups (P < 0.05).

CONCLUSIONS

Perindopril may help prevent the progression of diabetic glomerulopathy, and the inhibition of renin angiotensin system activity may be a mechanism for this action.

[The study of biocompatibility of titanium in middle ear cave of guinea-pig]

In order to supply full objective basis about tympanoplasty with titanium, 30 middle ear caves of guinea-pigs were implanted titanium ring in accordance with different time groups. Both before and after titanium ring were implanted, the guinea-pigs were detected in biochemical criterion of blood, titanium content of the hair, the changing of auditory threshold, tissue structural of middle ear and inner ear by energy spectrometry, electro-physiology, microscopy and scanning electron microscopy. The results showed that function of hepatorenal and titanium content of hair haven't significant change between pre- and postimplantation of titanium ring. Only 10 days group, it appeared the rising of auditory threshold and inverting of cilia by ABR and scanning electron microscopy. In 10 days and 1 month groups, there were blood stain and inflammatory cells under mucosa. The results suggested that titanium is good biocompatibility and no toxic for organism and mucosa.

Inhibition of apoptosis in chlamydia-infected cells: blockade of mitochondrial cytochrome c release and caspase activation

We report that chlamydiae, which are obligate intracellular bacterial pathogens, possess a novel antiapoptotic mechanism. Chlamydia-infected host cells are profoundly resistant to apoptosis induced by a wide spectrum of proapoptotic stimuli including the kinase inhibitor staurosporine, the DNA-damaging agent etoposide, and several immunological apoptosis-inducing molecules such as tumor necrosis factor-alpha, Fas antibody, and granzyme B/perforin. The antiapoptotic activity was dependent on chlamydial but not host protein synthesis. These observations suggest that chlamydia may encode factors that interrupt many different host cell apoptotic pathways. We found that activation of the downstream caspase 3 and cleavage of poly (ADP-ribose) polymerase were inhibited in chlamydia-infected cells. Mitochondrial cytochrome c release into the cytosol induced by proapoptotic factors was also prevented by chlamydial infection. These observations suggest that chlamydial proteins may interrupt diverse apoptotic pathways by blocking mitochondrial cytochrome c release, a central step proposed to convert the upstream private pathways into an effector apoptotic pathway for amplification of downstream caspases. Thus, we have identified a chlamydial antiapoptosis mechanism(s) that will help define chlamydial pathogenesis and may also provide information about the central mechanisms regulating host cell apoptosis.

Immune versus natural selection: antibody aldolases with enzymic rates but broader scope

Structural and mechanistic studies show that when the selection criteria of the immune system are changed, catalytic antibodies that have the efficiency of natural enzymes evolve, but the catalytic antibodies are much more accepting of a wide range of substrates. The catalytic antibodies were prepared by reactive immunization, a process whereby the selection criteria of the immune system are changed from simple binding to chemical reactivity. This process yielded aldolase catalytic antibodies that approximated the rate acceleration of the natural enzyme used in glycolysis. Unlike the natural enzyme, however, the antibody aldolases catalyzed a variety of aldol reactions and decarboxylations. The crystal structure of one of these antibodies identified the reactive lysine residue that was selected in the immunization process. This lysine is deeply buried in a hydrophobic pocket at the base of the binding site, thereby accounting for its perturbed pKa.

Production, specificity, and functionality of monoclonal antibodies to specific peptide-major histocompatibility complex class II complexes formed by processing of exogenous protein

Several unanswered questions in T cell immunobiology relating to intracellular processing or in vivo antigen presentation could be approached if convenient, specific, and sensitive reagents were available for detecting the peptide-major histocompatibility complex (MHC) class I or class II ligands recognized by alphabeta T cell receptors. For this reason, we have developed a method using homogeneously loaded peptide-MHC class II complexes to generate and select specific mAb reactive with these structures using hen egg lysozyme (HEL) and I-Ak as a model system. mAbs specific for either HEL-(46-61)-Ak or HEL-(116-129)-Ak have been isolated. They cross-react with a small subset of I-Ak molecules loaded with self peptides but can nonetheless be used for flow cytometry, immunoprecipitation, Western blotting, and intracellular immunofluorescence to detect specific HEL peptide-MHC class II complexes formed by either peptide exposure or natural processing of native HEL. An example of the utility of these reagents is provided herein by using one of the anti-HEL-(46-61)-Ak specific mAbs to visualize intracellular compartments where I-Ak is loaded with HEL-derived peptides early after antigen administration. Other uses, especially for in vivo tracking of specific ligand-bearing antigen-presenting cells, are discussed.

[Applied anatomy of osteo-periosteal flap pedicled with superior malleolar branch of anterior tibial artery]

In order to investigate the blood supply of osteo-periosteal flap of lateral inferior part of tibia, 40 lower limbs of adult cadavers were observed. The result showed that the superior malleolar branch was the biggest branch on the lateral inferior part of tibia and served as the main blood supply to the above area. It originated from the anterior tibial artery, 3.1 +/- 0.8 cm above the intermalleolar line. During its way to the anterior border of the tibia, it gave out the ascending and descending branches. The ascending branch was along the anterior border upward and anastomosed with the musculo-periosteol branch of the anterior tibial artery at the level of 6.3 +/- 1.3 cm above the intermalleolar line. The decending branch was anastomosed with the anterior medial malleolar artery. For the anastomosis between the superior malleolar branch with the peripheral vessels, the osteo-periosteol flap could be designed at the lateral side of the lower part of tibia in size of 8-10 cm x 4-6 cm. This was a new donor area of osteo-periosteol flap for repair of non-union of bone in lower end of tibia or arthrodesis of the ankle joint.

Antigen-unspecific B cells and lymphoid dendritic cells both show extensive surface expression of processed antigen-major histocompatibility complex class II complexes after soluble protein exposure in vivo or in vitro

Intravenous (i.v.) injection of high amounts of soluble proteins often results in the induction of antigen-specific tolerance or deviation to helper rather than inflammatory T cell immunity. It has been proposed that this outcome may be due to antigen presentation to T cells by a large cohort of poorly costimulatory or IL-12-deficient resting B cells lacking specific immunoglobulin receptors for the protein. However, previous studies using T cell activation in vitro to assess antigen display have failed to support this idea, showing evidence of specific peptide-major histocompatibility complex (MHC) class II ligand only on purified dendritic cells (DC) or antigen-specific B cells isolated from protein injected mice. Here we reexamine this question using a recently derived monoclonal antibody specific for the T cell receptor (TCR) ligand formed by the association of the 46-61 determinant of hen egg lysozyme (HEL) and the mouse MHC class II molecule I-Ak. In striking contrast to conclusions drawn from indirect T cell activation studies, this direct method of TCR ligand analysis shows that i.v. administration of HEL protein results in nearly all B cells in lymphoid tissues having substantial levels of HEL 46-61-Ak complexes on their surface. DC readily isolated from spleen also display this TCR ligand on their surface. Although the absolute number of displayed ligands is greater on such DC, the relative specific ligand expression compared to total MHC class II levels is similar or greater on B cells. These results demonstrate that in the absence of activating stimuli, both lymphoid DC and antigen-unspecific B cells present to a similar extent class II-associated peptides derived from soluble proteins in extracellular fluid. The numerical advantage of the TCR ligand-bearing B cells may permit them to interact first or more often with naive antigen-specific T cells, contributing to the induction of high-dose T cell tolerance or immune deviation.

Mapping epitopes of neutralizing monoclonal antibodies using phage random peptide libraries

Identification of protective determinants from microbial proteins is a necessary step in the rational design of subunit vaccines. We have previously used a synthetic peptide scan (Pepscan) assay to map a panel of eight neutralizing monoclonal antibodies (mAb; designated as C1.1 to C1.8) to a common motif sequence from Chlamydia trachomatis. In the present study, five of the eight mAbs were used to screen phage random peptide libraries. mAbs C1.1 and C1.3 selected a motif sequence of G-L-X-N-D from a pIII-based phage random peptide library and a motif sequence of G-X-X-N-D from a pVIII-based random peptide library while mAbs C1.6 to C1.8 failed to select recognizable motifs from either of the phage libraries. However, C1.6 to C1.8 bound to the same motif sequence displayed on phage when the appropriate conformational constraints were imposed onto the motif sequence. Thus the specificity of the mAbs identified on Pepscan assays correlates with the mAbs' dependence on local epitope constraints displayed on the phage surface.

Antigen presentation by MHC class II molecules: invariant chain function, protein trafficking, and the molecular basis of diverse determinant capture

Major histocompatibility complex class II molecules are heterodimeric integral membrane proteins whose primary function is the presentation of antigenic peptides derived from proteins entering the endocytic pathway to CD4+ T lymphocytes. To accomplish this physiologic function, class II molecules must assemble in the secretory pathway without undergoing irreversible ligand association at that site, traffic efficiently to the endocytic pathway, and productively interact with protein ligands in these organelles before their ultimate expression on the plasma membrane. Here we review our work describing how invariant chain promoters the assembly and transport process, the complex itinerary of class II-invariant chain complexes through the endocytic pathway, the role of large protein fragments as substrates for class II binding, and the existence of a second pathway for antigen capture by mature class II molecules that complements that involving newly synthesized dimers. We integrate these observations into a coherent model for the operation of a class II-dependent antigen processing and presentation system able to capture diverse antigenic determinants present in proteins of varying structure.

Related leucine-based cytoplasmic targeting signals in invariant chain and major histocompatibility complex class II molecules control endocytic presentation of distinct determinants in a single protein

Leucine-based signals in the cytoplasmic tail of invariant chain (Ii) control targeting of newly synthesized major histocompatibility complex class II molecules to the endocytic pathway for acquisition of antigenic peptides. Some protein determinants, however, do not require Ii for effective class II presentation, although endocytic processing is still necessary. Here we demonstrate that a dileucine-based signal in the cytoplasmic tail of the class II beta chain is critical for this Ii-independent presentation. Elimination or mutation of this signal reduces the rate of re-entry of mature surface class II molecules into the endocytic pathway. Antigen presentation controlled by this signal does not require newly synthesized class II molecules and appears to involve determinants requiring only limited proteolysis for exposure, whereas the opposite is true for li-dependent determinants. This demonstrates that related leucine-based trafficking signals in li and class II control the functional presentation of protein determinants with distinct processing requirements, suggesting that the peptide binding sites of newly synthesized versus mature class II molecules are made available for antigen binding in distinct endocytic compartments under the control of these homologous cytoplasmic signals. This permits capture of protein fragments produced optimally under distinct conditions of pH and proteolytic activity.

Evidence that binding site occupancy is necessary and sufficient for effective major histocompatibility complex (MHC) class II transport through the secretory pathway redefines the primary function of class II-associated invariant chain peptides (CLIP)

Invariant chain (Ii) associates with newly synthesized class II molecules in the endoplasmic reticulum (ER), an interaction that has been shown to interfere with peptide binding to class II molecules. The class II-associated invariant chain peptide (CLIP) region (residues 81-104) of Ii is believed to mediate this inhibition by engaging the binding domain of class II like an antigenic peptide. Together, these findings have given rise to a model in which CLIP association with the class II groove acts to prevent inappropriate presentation of peptides imported into the ER for association with major histocompatibility complex class I molecules. However, the properties of class II molecules synthesized by cells lacking coexpressed Ii are at least superficially inconsistent with this paradigm in that they do not show clear evidence of peptide acquisition. At the same time, we have previously shown the shortest form of Ii still containing CLIP to play an essential role in regulation of early class II molecule assembly and transport in the secretory pathway. Using covalent peptide technology, we now show that occupancy of the class II binding site in the ER regulates class II trafficking to the Golgi complex, an event that is the locus of the major defect in cells of Ii-deficient mice. These data argue that CLIP occupies the class II binding site, not to prevent interaction with short peptides meant for class I, but rather to maintain the structural integrity of class II molecules that are labile without engaged binding regions, and that would also associate with intact proteins in the ER if left unoccupied. By these means, CLIP occupancy of the class II binding site promotes effective export of useful class II molecules for endocytic peptide acquisition.

Experimental and theoretical study of the adsorption behavior and mass transfer kinetics of propranolol enantiomers on cellulase protein as the selector

The thermodynamics and mass transfer kinetics of the retention of the R and S enantiomers of propranolol were investigated on a system comprising an acetic acid buffer solution as the mobile phase and the protein cellobiohydrolase I immobilized on silica as the stationary phase. The bi-Langmuir isotherm model fitted best to each set of single-component isotherm data. The monolayer capacity of the nonchiral type of adsorption sites was 22.9 mM. For the chiral type of sites, it was 0.24 mM for the R enantiomer and 0.64 mM for the S enantiomer. Peak tailing was observed, even at very low concentrations allowing operation of the low-capacity chiral sites under linear conditions. This tailing can be explained on the basis of heterogeneous mass transfer kinetics. At higher concentrations, which are often used in analytical applications, the isotherms on the chiral sites no longer have a linear behavior, and peak tailing is consequently more pronounced. Under those conditions, peak tailing originates from the combined effect of heterogeneous thermodynamics and heterogeneous mass transfer kinetics. These complex phenomena are explained and modeled using the transport-dispersive model with a solid film linear driving force model modified to account for heterogeneous mass transfer kinetics. The rate coefficient of the mass transfer kinetics was found to be concentration dependent.

[Comparison between Chinese and Tibetan pulsology]

There is considerably close relationship in the origins of pulse feeling between Chinese and Tibetan medicine. Pulsology of both systems were mutually infiltrated, hence, there are many similarities, and with its own uniqueness in clinical application at the same time. This paper deals with the problem under the subheadings of preparation before taking the pulse and the optimal time for taking the pulse, etc.

[The hepatitis A virus isolated and adapted in human diploid fibroblast cells (KMB17)]

Three hepatitis A virus (HAV) strains (L8, H32 and H52) were isolated from stool specimens of hepatitis A patients during an epidemic in 1988 in Shanghai and were adapted to grow in human diploid fibroblast cell strain (KMB17). The strains were serially carried through 10 passages in KMB17. The infectious titrations of these virus strains cultured for 28 days at the 10th passage were high up to 7.0-7.75 log TCID50/ml. The maximum virus yields occured in the 28th day after infection. Immune electronic microscopic studies revealed that the viral particles were 27-30 nm in diameter. The strains were neutralized by specific anti-HAV serum. Special fluorescent stained particles were observed clearly in the infected cellular plasma by direct IF. The above data suggest that the three strains are HAV and may be useful for further study.

[Transplantation of pedicled pisiform bone to replace lunate bone with aseptic necrosis]

OBJECTIVE

To find out a new and effective method for the treatment of aseptic necrosis of lunate bone.

METHODS

Blood supply and morphology of pisiform bone were investigated in 25 upper limbs and 57 sets of carpal bone from adult cadavers on the basis of anatomical study. The lunate bone was replaced with pisiform bone of pedicled blood vessel and tendon of musculus flexor earpiulnaris in 17 patients with aseptic necrosis of lunate bone (stage III).

RESULTS

The patients were followed up for 18-46 months (average of 28 months). Complete relief of pain was obtained in all of the patients, and the range of motion of their wrists was improved. Grip strength was increased by 48.2%. Radiograph showed normal location of transferred pisiform bone without osteosclerosis and atrophy in 16 patients. Atrophy of pisiform bone was found 2 years after operation in one patient. In the 17 patients, 15 resumed their original jobs and 2 changed their jobs for other reasons.

CONCLUSION

We consider that the carpal bone chain can be completely preserved by transplantation of pedicled pisiform bone, which it is an effective method to treat aseptic necrosis stage III of lunate bone.

[Technological studies of effects of inclusion on pericarpium Citri reticulatae volatile oil-beta-cyclodextrin]

The effects of inclusion on Pericarpium Citri Reticulatae volatile oil-beta-cyclodextrin were studied by comparing four methods saturation, grinding, liquid to liquid and liquid to gas. The utilization ratio of oil, the ratio of oil in inclusion complex and the recovery of inclusion complex were used as the criteria in evaluating the inclusion effectiveness. The results showed that the saturation method was the best.

[Extraction of intraocular magnetic foreign body using intraocular earth magnet]

PURPOSE

To determine the effects of extraction of intraocular magnetic foreign body with intraocular earth magnet (IOEM).

METHOD

From 1992 to 1994, 22 cases with intraocular foreign body were treated with self-made intraocular earth magnet (IOEM): 2 patients with foreign body remained on lens, 7 on posterior segment of global wall, 12 lodged in the post pole of retina and 1 on the surface of optic disk. These patients were operated under microscope. The foreign bodies on the posterior segment were removed by using IOEM combined with pars plana vitrectomy.

RESULT

The foreign bodies of these 22 patients were successfully removed with one operation respectively. The minimum volume of the foreign bodies was 0.5 x 0.5 x 0.5 mm3. The maximum volume of the foreign bodies was 5 x 2 x 1.5 mm3. The average maximum diameter of the foreign bodies was 2.47 +/- 1.2 mm.

CONCLUSION

Intraocular earth magnet (IOEM) is a permanent magnetic instrument with moderate magnetic power. Direct observation and detachment of the foreign body with ocular tissue are necessary during the remowal of the forreign body. This instrument is suitable for intraocular microsurgery, can be handled easily, used for extraction of foreign bodies in anterior chamber, on turbid lens and in vitreous body, in removing foreign bodies in vitreous chamber with obvious injured retina and on posterior segment, the surface of retina, and can also be applied toextract foreign bodies on optic disk as well asforeign bodies partly oldged on global wall.

Conformational mimicry of a chlamydial neutralization epitope on filamentous phage

Conformational constraints were imposed on a peptide epitope from Chlamydia trachomatis to improve its ability to elicit antibodies that cross-react with native antigen. Appropriate constraints were discovered by a strategy that required no prior knowledge of the epitope's native conformation. First, we constructed a library of 3.2 x 10(5) peptides in which the epitope's contact residues were subject to random conformational constraints, each constrained peptide being fused genetically to the surface of a filamentous phage vector. Next, we selected phage displaying the most native-like peptides in the library by affinity purification with antibodies that bind the epitope only in its native conformation. Finally, we immunized mice with the selected phage and titered the resulting antisera against both whole cells and unconstrained peptide. The ratio of anti-cell titer to anti-peptide titer, which reflects the channeling of the antibody response to the native epitope, was up to five times higher for affinity-selected phage than for unselected peptide phage. In this case, therefore, "antigenic fitness," the ability of a peptide to bind antibodies specific for native epitope, correlated with "immunogenic fitness," its ability to elicit antibodies that are effective against the native antigen on an invading pathogen. If the correlation is general, surveying thousands or millions of peptides for antigenic fitness with phage display technology may be a simple but effective pre-screen for immunogenic fitness, which is costly to assess directly.

Antibody recognition of a neutralization epitope on the major outer membrane protein of Chlamydia trachomatis

Two BALB/c mice were immunized with serovar C Chlamydia trachomatis elementary bodies, and 63 hybridomas producing monoclonal antibodies to C. trachomatis were recovered. Eight hybridomas which were specific for an identical peptide epitope (AGLQND) in serovar C major outer membrane protein variable domain I were identified. Detailed immunochemical study of the antigen-antibody interaction and genetic characterization of the antibody variable-region gene sequences showed that distinct B-cell clonal lineages were elicited by the epitope sequence. Since each antibody had a distinct pattern of fine specificity for recognition of the epitope and displayed different degrees of cross-reactivity with a related serovar (serovar A), we conclude that B-cell recognition of an immunodominant neutralization epitope can be pleiotropic. Differences in B-cell recognition of a neutralization epitope may delay the emergence by mutation of antigenic-drift variants of the C. trachomatis major outer membrane protein.

Survey of plant short tandem DNA repeats

Length variations in simple sequence tandem repeats are being given increased attention in plant genetics. Some short tandem repeats (STRs) from a few plant species, mainly those at the dinucleotide level, have been demonstrated to show polymorphisms and Mendelian inheritance. In the study reported here a search for all of the possible STRs ranging from mononucleotide up to tetranucleotide repeats was carried out on EMBL and GenBank DNA sequence databases of 3026 kb nuclear DNA and 1268 kb organelle DNA in 54 and 28 plant species (plus algae), respectively. An extreme rareness of STRs (4 STRs in 1268 kb DNA) was detected in organelle compared with nuclear DNA sequences. In nuclear DNA sequences, (AT)n sequences were the most abundant followed by (A)n · (T)n, (AG)n · (CT)n, (AAT)n · (ATT)n, (AAC)n · (GTT), (AGC)n · (GCT)n, (AAG)n · (CTT)n, (AATT)n · (TTAA)n, (AAAT)n · (ATTT)n and (AC)n · (GT)n sequences. A total of 130 STRs were found, including 49 (AT)n sequences in 31 species, giving an average of 1 STR every 23.3 kb and 1 (AT)n STR every 62 kb. An abundance comparable to that for the dinucleotide repeat was observed for the tri- and tetranucleotide repeats together. On average, there was 1 STR every 64.6 kb DNA in monocotyledons versus 1 every 21.2 kb DNA in dicotyledons. The fraction of STRs that contained G-C basepairs increased as the G+C contents went up from dicotyledons, monocotyledons to algae. While STRs of mono-, di- and tetranucleotide repeats were all located in non coding regions, 57% of the trinucleotide STRs containing G-C basepairs resided in coding regions.

[Clinical analysis of 160 cases with the magnetic foreign bodies in the posterior segment of the eye]

One hundred and sixty cases of magnetic foreign bodies in the posterior segment of the eye are reported. Most of the foreign bodies are small (61.2% are less than 2mm) and near the wall of the eye (73.7% are less than 2mm). 110 cases were successfully operated in conventional way and just 20 cases needed to have vitrectomy. The result of the operation depends on the damage of the eye, location of the foreign body and the complication of the operation. In 77.6% of the cases, the wound was on the cornea or limbus. That is one of the important factors to affect the patients' postoperation vision.

Immunogenicity evaluation of a lipidic amino acid-based synthetic peptide vaccine for Chlamydia trachomatis

Lipidic amino acid-based synthetic peptides derived from the variable domains (VD) of Chlamydia trachomatis outer membrane protein 1 were evaluated as potential candidate sequences in a vaccine. A peptide sequence designated P2 from the VD IV of serovar B contained a B cell epitope capable of eliciting antibodies binding to serovar B elementary bodies (EB) and a T helper site capable of presentation by multiple H-2 alleles. Polymerization of the P2 into polylysine to form lipid core peptides (LCP) significantly enhanced immunogenicity compared with P2 monomer alone. The LCP system incorporates lipidic amino acids into the polylysine system and enhances lipophobicity and membrane binding effects of the peptide. A second peptide sequence derived from the VD I of serovar C was cosynthesized with P2 into lipidic polylysine LCP and was designated LCP-H1. Antibodies to this construct reacted at high titer with EB of the three major trachoma causing C. trachomatis serovars A, B, and C. LCP-H1 was immunogenic among four of five murine H-2 alleles. Pepscan analysis showed that the fine specificity of antibodies generated to LCP-H1 were directed to the predetermined neutralizing epitope sequences. An in vitro HAK cell neutralization assay showed that LCP-H1 elicited neutralizing antibodies to serovars A, B, and C, but these were of low titer. Because LCP-H1 antibodies bound to the peptide sequence with 10-100-fold higher titer than to EB, the low neutralization titers most likely result from conformational differences between the synthetic peptide and antigenic sites on the native organism. Modification of LCP-H1 to incorporate a predefined conformation may result in improved antigenic properties.

Immunogenicity evaluation of a lipidic amino acid-based synthetic peptide vaccine for Chlamydia trachomatis

Lipidic amino acid-based synthetic peptides derived from the variable domains (VD) of Chlamydia trachomatis outer membrane protein 1 were evaluated as potential candidate sequences in a vaccine. A peptide sequence designated P2 from the VD IV of serovar B contained a B cell epitope capable of eliciting antibodies binding to serovar B elementary bodies (EB) and a T helper site capable of presentation by multiple H-2 alleles. Polymerization of the P2 into polylysine to form lipid core peptides (LCP) significantly enhanced immunogenicity compared with P2 monomer alone. The LCP system incorporates lipidic amino acids into the polylysine system and enhances lipophobicity and membrane binding effects of the peptide. A second peptide sequence derived from the VD I of serovar C was cosynthesized with P2 into lipidic polylysine LCP and was designated LCP-H1. Antibodies to this construct reacted at high titer with EB of the three major trachoma causing C. trachomatis serovars A, B, and C. LCP-H1 was immunogenic among four of five murine H-2 alleles. Pepscan analysis showed that the fine specificity of antibodies generated to LCP-H1 were directed to the predetermined neutralizing epitope sequences. An in vitro HAK cell neutralization assay showed that LCP-H1 elicited neutralizing antibodies to serovars A, B, and C, but these were of low titer. Because LCP-H1 antibodies bound to the peptide sequence with 10-100-fold higher titer than to EB, the low neutralization titers most likely result from conformational differences between the synthetic peptide and antigenic sites on the native organism. Modification of LCP-H1 to incorporate a predefined conformation may result in improved antigenic properties.

Continuous B-cell epitopes in Chlamydia trachomatis heat shock protein 60

B-cell peptide epitopes in chlamydial heat shock protein 60 (hsp60) were elucidated with antisera from 13 rabbits immunized with Chlamydia trachomatis serovars B, C, and L2 and antisera from eight women with C. trachomatis-associated ectopic pregnancies. Thirteen major epitopes were identified with the human sera, 10 of which were also observed with rabbit antisera. Seven of the 13 epitopes recognized by human antisera exhibited cross-reactive antibody binding to homologous peptide sequences in human hsp60. Self-reactive B-cell immunity to hsp60 may contribute to chlamydial disease pathogenesis.

[Vitrectomy combined with intravitreal injection of drugs for the management of advanced suppurative endophthalmitis]

Sixty cases (60 eyes) of advanced suppurative endophthalmitis treated by a combination of vitrectomy and intravitreal injection of drugs (antibiotics or/and corticosteroids) were investigated perspectively. Of the 60 cases, 43 were infected after trauma, 12 were infected after surgical procedures, while the others were of unknown causes. During the follow-up period of 1/2-5 years, 57 cases (95%) retained functioning eyes, the postoperative visual acuity of 34 eyes (57%) being 0.05 or better and the postoperative visual acuity of 17 eyes (28%) 0.4 to 1.0. The advantages of the therapeutic regimen are analyzed. We believe that it is the most effective therapy for suppurative endophthalmitis. The timing of the operation and the factors influencing the results are discussed. This report also presents our clinical experiences in the management of advanced suppurative endophthalmitis.

[Protective effects of Panax quinquefolium saponin on oxidative damage of cultured rat cardiac cells]

When cultured cardiac cells of rats were exposed to X-XOD containing medium, the absolute values of electronic parameters were decreased the percentage of beating clusters reduced and the microscopic structure destroyed. PQS significantly converted all the indices, which shows that PQS can protect the cells from oxidative damage.

Antibody responses to the chlamydial heat shock proteins hsp60 and hsp70 are H-2 linked

The effects of both H-2 and non-H-2 genes on antibody responses to two Chlamydia trachomatis heat shock proteins (hsp60 and hsp70) were investigated. These chlamydial proteins are homologs of Escherichia coli GroEL (hsp60) and DnaK (hsp70) and are highly sequence conserved between bacterial and mammalian sources. Antibody responses among 17 different strains of mice immunized with C. trachomatis serovar B and serovar C elementary bodies were evaluated by immunoblot, radioimmunoprecipitation and enzyme-linked immunosorbent assay. Antibody responses to the two proteins displayed host genetic restriction. Of six distinctive H-2 haplotypes, only H-2d generated high antibody responses to hsp70. Five of the six H-2 haplotypes, i.e., H-2a, H-2d, H-2k, H-2q, and H-2s, produced high antibody responses to hsp60. Only the H-2b-bearing strain had low antibody responses to hsp60. By using congenic and H-2 recombinant strains, the genes responsible for regulating antibody responses to hsp70 and hsp60 were mapped to the K-IA region of the H-2 locus. In F1 hybrid crosses between high and low responders, high responses to hsp60 and hsp70 were dominant traits. Other genes outside the H-2 locus also influenced antibody responses to hsp60 and hsp70, since inbred strains of identical H-2 but different background genes displayed variable antibody responses to the proteins. The genetic control of murine immune responses to C. trachomatis hsp60, a putative chlamydial immunopathologic antigen, suggests that a similar genetic mechanism may also exist in humans, and this observation may help to explain the observed variability in the spectrum of chlamydial diseases seen in humans.

[Thixotropic properties of whole blood in children with congenital heart disease]

The thixotropic parameters of whole blood in two groups of children with congenital heart disease (CHD) were measured. Group 1. cyanotic heart disease (CCHD), 20 cases; Group 2. acyanotic heart disease (ACHD), 30 cases. Fifty healthy children were controls matched with the patients in sex and age. Their thixotropic parameters were compared; the paired t-test was used. In the children with CCHD, the hematocrit (HCT), the yield stress (tau 0) the Newtonian contribution of viscosity (mu), the equilibrium value of the structural parameter (A), the apparent viscosity at 2.37 sec-1 (eta s) and the Non-Newtonian contribution of viscosity (eta s-mu) were significantly higher than those in corresponding control groups. In the children with ACHD, only the values of tau 0, eta s-mu, and eta s were higher than those in control groups. All of the thixotropic parameters in CCHD group were significantly higher than those in ACHD group. Thus we described quantitatively CHD in terms of thixotropy of blood. The thixotropic parameters of blood could be used as indexes of severity for pathologic changes of CHD.

Antigenic analysis of the chlamydial 75-kilodalton protein

Both B- and T-cell immunogenicity of a chlamydial 75-kDa protein was analyzed by using 131 partially overlapped decapeptide homologs of the 75-kDa protein from Chlamydia trachomatis serovar L2. Six rabbit antiserum specimens raised with serovars B, C, and L2 were used to assay the antibody reactivities of the decapeptides. Seventy-five of the 131 decapeptides were recognized by at least one antiserum specimen, and two peptides were found to be immunodominant and surface accessible on native organisms. The same set of decapeptides were cleaved from the pins and tested for their T-cell-stimulating activity in an in vitro proliferation assay. A single decapeptide was able to stimulate proliferation of chlamydial antigen-primed lymph node T cells from BALB/c mice.

[Ca2+ channel blocking effect of panaxadiol saponins and panaxatriol saponins of cultured cardiac cells]

It was found that PDS and PTS decreased the action potential parameters of the cultured myocardiocytes in a dosage-dependent way. The effects of PDS 1000 micrograms/ml, PTS 200 micrograms/ml were in correspondence with the known Ca2+ channel blocker Mn2+ 0.05 micrograms/ml. Washing out, administration of epinephrine 10 micrograms/ml or Ca2+ 80 micrograms/ml were able to reverse the action potential from inhibition. The above results indicate that both PDS and PTS have Ca2+ channel blockade action.

[Scanning electron microscopic identification of hairs on surface of fruits and seeds of Chinese medicinal plants]

A comparative identification of hairs on surfaces of fruits and seeds of some Chinese medicines has been made, and a key to 13 kinds of hairs has been compiled. According to the characters of hairs, it is possible to identify some Chinese drugs in powder form.

[Study on thixotropic parameters of whole blood from healthy children]

With low shear-30 rheometer, the authors used a modified protocol to measure thixotropic parameters of whole blood from 200 healthy newborns and children, so as to suggest the normal range of blood thixotropic parameters in four age groups, namely, the newborns, 1 year- group, 5 year- and 10-15 year group. The results demonstrated that the thixotropic parameters in the newborn group were higher than those in other three groups. However, these thixotropic parameters in the group 1-10 years were lower than those in the 10-15 year group. No significant sex differences were noted among the fore three groups, but sex differences appeared obviously in the 10-15 year group. It implied that the changes relying on the age is consistent with children's growth, development and physiologic activities.

[Research on thixotropic properties of whole blood in patients with ischemic stroke and its high risk]

So far, few papers on alteration of thixotropic properties of blood from patients with cerebrovascular disease have been found. We measured the thixotropic parameters of blood from 92 patients suffering from cerebrovascular diseases. These patients were divided into five groups. Group I consisted of 14 male patients with cerebral arteriosclerosis (CA) (aged 61.7 +/- 8.2 years) and Group II, 12 male patients with transient cerebral ischemic attack (TIA) (64.4 +/- 7.8 years). All of patients in groups III (22 male old patients, 66.6 +/- 5.1 years), IV (24 male middle-aged patients 53.7 +/- 2.8 years), and V (20 female patients 58.4 +/- 13.8 years) were suffering from cerebral thrombosis. These 92 patients and 92 selected healthy subjects were pair matched in sex and age. Using paired t-test, we compared their thixotropic parameters. The results showed that the yield stress (tau 0), the equilibrium value of the structural parameter (A), the apparent viscosity at 2.37 s-1 (eta s), and non-Newtonian contribution of viscosity (eta s-mu) in groups I, II and III were significantly higher than those in the corresponding control groups. The values of tau 0, A, eta s, (eta s-mu) and eta p of blood in group V were higher than those in the control group; only the values of tau 0, eta p, (eta s-mu) of blood in group IV were higher than those in the control group. No significant difference in the thixotropic parameters was noted among groups I, II and III. The results suggest that the patients with cerebrovascular diseases had evidently increased number and degree of RBC aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)

[A new approach to measurement of thixotropic properties of whole human blood]

With the Low Shear 30 rheometer and its accessory instruments, four torque decay curves of whole human blood from a healthy young man were recorded at shear rate 1.285, 1.747, 2.37 and 3.23 s-1 respectively for pretesting. The modified Levenberg-Marquardt non-linear parameter estimating method was used to calculate the thixotropic parameters by following Huang's equation. The results showed that the thixotropic properties of whole human blood could be measured by recording two torque decay curves. This approach is much easier than Huang's method. We have adopted it to measure the thixotropic properties of whole blood from healthy young men (n = 32) and young women (n = 32). The results were comparable to those in Huang's reports of 1976. The coefficients of variations of most parameters in our measurement were less than those in Huang's reports. Meanwhile, we analysed the advantage in using the new method and made some suggestions to improve the measurement accuracy in human blood thixotropy.

[The establishment of hemorheological data base and its applications]

This hemorheological data base was established with an Apple II computer. The covering technique was applied to deal with its lacks of memories. This data base had a mutual administration system and complete managing functions including inputting, inquiring, printing, transferring, revising functions and so on. More than twenty hemorheological parameters involving apparent viscosities of whole human blood, plasma viscosity, viscoelasticity and thixotropy indices, were saved in the way of paging mode. Meanwhile, this data base had a common mathematical statistics system in recently medical use. It included monovariable linear and nonlinear regressions, t-test, multiple linear regression, cluster analysis etc. Therefore, this data base can be conveniently utilized to analyze the hemorheological data comprehensively. Besides the establishment of normal hemorheological indices, this data base equipped a primary method of quantitative diagnosis through hemorheological indices, it gave a new method to diagnose some diseases and to observe their curing process.

[The role of hemorheologic changes in the pathogenesis of acute hemorrhagic necrotizing pancreatitis]

The hemorheologic alterations were studied in experimental acute hemorrhagic necrotizing pancreatitis (AHNP) which was induced by injection of 5% sodium taurocholate into the main pancreatic duct. The results showed that during the early stage of AHNP, all of hemorheologic parameters were significantly elevated, and continually increased at the rest intervals. The authors suggested that the blood viscosity and hematocrit increase, red blood cells tend to aggregate, and erythrocyte deformation decrease are the causation of pancreatic microcirculatory disturbances and promoting pancreatic progressive necrosis. After using low molecular dextran and Salvia miltiorrhizae, the hemorheologic alterations in AHNP were recovered, and the histologic observation improved. Our data indicate the hemorheologic disturbances is one of the key factors in the pathogenesis of AHNP.

[Visco-elasticity of whole blood in healthy young men and women]

The measurement of visco-elastic properties of blood of the Chinese is very important for theoretical research and clinical practice. This paper reports the study of the visco-elastic properties, rheological parameters and several biochemical components of the whole blood in 146 healthy young students. No significant difference in the concentrations of globulin, cholesterol, fibrinogen and blood sugar between the male group and female group could be found. The level of albumin, hemoglobin and triglyceride in the male group was significantly higher than that in the female group. The rheological measurement demonstrated that plasma viscosities in both the male and female groups had no significant differences and that the values of HCT, apparent viscosities at high (51.2 s-1) and low (0.512 s-1) shear rates and AI in the male group had higher values of ESR and OD than the female group. The visco-elastic parameters of whole blood, including eta', eta", G' and lambda, were higher in the male group than the female group. The physiological meaning of these differences between the groups is also discussed in the paper.