The galE gene of Campylobacter jejuni is involved in lipopolysaccharide synthesis and virulence

Lipopolysaccharide (LPS) is one of the main virulence factors of gram-negative bacteria. The LPS from Campylobacter spp. has endotoxic properties and has been shown to play a role in adhesion. We previously cloned a gene cluster (wla) which is involved in the synthesis of the Campylobacter jejuni 81116 LPS molecule. Sequence alignment of the first gene in this cluster indicated similarity with galE genes. These genes encode a UDP-glucose 4-epimerase, which catalyzes the interconversion of UDP-galactose and UDP-glucose. A Salmonella galE mutant was transformed with the galE gene from C. jejuni. The LPS analysis of wild-type, galE, and complemented galE Salmonella strains showed that the C. jejuni galE gene could restore the smooth wild-type Salmonella LPS. A UDP-glucose 4-epimerase assay was used to demonstrate that the galE gene from C. jejuni encoded this epimerase. We constructed a C. jejuni galE mutant which expressed a lipid A-core molecule of reduced molecular weight that did not react with antiserum raised against the parental strain. These results show an essential role for the galE gene in the synthesis of C. jejuni LPS. The galE mutant also showed a reduction in its ability to adhere to and invade INT407 cells. However, it was still able to colonize chickens to the same level as the wild-type strain. The serum resistance and hemolytic activity of this mutant were not changed compared to the parent strain. The ability of the mutant to take up DNA and integrate it in its genome was reduced 20-fold. These results show that LPS of C. jejuni is an important virulence factor.

A dendritic cell line genetically modified to express CTLA4-IG as a means to prolong islet allograft survival

BACKGROUND

Dendritic cells are potent antigen-presenting cells that bind allogeneic T cells. They are thus candidates for targeting immunoregulatory molecules to the alloreactive T cell compartment and suppressing the alloimmune response.

METHOD

A dendritic cell line derived from the BALB/c mouse (H2d) was genetically modified to express the immunoregulatory molecule CTLA4-Ig. The ability of these dendritic cell transfectants to downregulate the alloimmune response was tested in an islet transplant model. Allogeneic C57Bl/6 (H2b) mice were rendered diabetic with streptozocin, and they received BALB/c islet (H2d) transplants. Mice were administered 25 million untransfected or CTLA4-Ig-transfected D2SC/1 cells i.v. on the day of islet transplantation and 6 days later[fnc].

RESULT

Mice treated with CTLA4-Ig-transfected D2SC/1 cells demonstrated prolonged allograft survival (mean = 20 days, median = 17 days, SD = 9.39) compared with mice treated with untransfected D2SC/1 cells (mean = 12 days, median = 11 days, SD=2.74) or untreated control mice (mean = 11 days, median = 11 days SD = 1.41). Third party allograft survival was not prolonged in mice receiving similar treatment.

CONCLUSIONS

These results demonstrate that a genetically modified dendritic cell line can suppress the alloimmune response and prolong islet allograft survival in an allospecific manner. The findings also suggest that genetically modified dendritic cells may be useful in targeting alloreactive T cells and prolonging allograft survival.

Interaction of PIP(2) with the XIP region of the cardiac Na/Ca exchanger

The sarcolemmal Na/Ca exchanger undergoes an inactivation process in which exchange activity decays over several seconds following activation by the application of Na to the intracellular surface of the protein. Inactivation is eliminated by an increase in membrane phosphatidylinositol 4,5-bisphosphate (PIP(2)). Inactivation is also strongly affected by mutations to a basic 20-amino acid segment of the exchanger known as the endogenous XIP region. The hypothesis that PIP(2) directly interacts with the XIP region of the exchanger was tested. First, we investigated the ability of a peptide with the same sequence as the XIP region to bind to immobilized phospholipid vesicles. (125)I-labeled XIP bound avidly to vesicles containing only a low concentration (<3%) of PIP(2). The binding was specific, in that binding was not displaced by other basic peptides. The effects of altering the sequence of XIP peptides also indicated binding specificity. Second, we examined the functional response to PIP(2) of exchangers with mutated XIP regions. Outward Na/Ca exchange currents were measured using the giant excised patch technique. The mutated exchangers either had no inactivation or accelerated inactivation. In both cases, the exchangers no longer responded to PIP(2) or to PIP(2) antibodies. Overall, the data indicate that the affinity of the endogenous XIP region for PIP(2) is an important determinant of the inactivation process.

[Kinetic fluorimetric determination of trace oxalate]

A new kinetic fluorimetric method for the determination of trace oxalate is described. The method is based on the enhancing effect of oxalate on the oxidation of butyl rhodamine B by potassium dichromate in the solution of hydrochloric acid. The linear range of the determination is 1.20-10.0 micrograms.mL-1. This method has been used to determine trace oxalate in spinach with satisfactory results.

[Effect of Bacillus megaterium on Gluconobacter oxydans in mixed culture]

To reveal the relationship between Bacillus megaterium and Gluconobacter oxydans in the mixed culture of vitamin C two-step fermentation, the effect of B. megaterium on the growth of G. oxydans and its synthesizing ability of 2-keto-L-gulonic acid(2KGA) was studied. The bioactive metabolites which could enhance the synthesis of 2KGA were isolated and purified by ultrafiltration, gel chromatography and SDS-polyacrylamide gel electrophoresis. Both the culture supernatant and the cytosol of B. megaterium could promote the proliferation of G. oxydans, and the active component in the culture supernatant was above 100 KDa. The culture suernatant could enhance the conversion of L-sorbose to 2KGA, while the cytosol could not. The active components in B. megaterium culture supernatant had molecular weight of 30-50 KDa and above 100 KDa, and the former was a kind of protein with an apparent molecular weight of about 35 KDa, which consisted of one sort of subunit and contained Fe and Zn elements.

Stability of Borrelia burgdorferi outer surface protein C under immune selection pressure

Outer surface protein (Osp) C immune pressure during persistent infection with Borrelia burgdorferi was examined in relation to genetic variation of ospC. Mice were infected with clonal B. burgdorferi sensu stricto (s.s.) N40 or B. afzelii PKo and then were hyperimmunized with homologous recombinant OspC or with decorin-binding protein A (DbpA) (controls). After 6 months, B. burgdorferi isolates were subjected to restriction enzyme analysis of the amplified ospC genes and were found to have no differences among 9 B. burgdorferi s.s. N40 and 9 B. afzelii PKo isolates from OspC hyperimmune mice or among 10 B. burgdorferi s.s. N40 and 10 B. afzelii PKo isolates from DbpA hyperimmune mice, compared with input inocula. Comparison of gene sequences among 4 B. burgdorferi s.s. N40 and 9 B. afzelii PKo isolates from OspC-immunized mice revealed no ospC variation from input inocula. Variation in ospC among B. burgdorferi isolates and species during chronic infection is not likely to be an important mechanism for immune evasion.

Decreased bone mineral density in female patients with systemic lupus erythematosus after long-term administration of Tripterygium Wilfordii Hook. F

OBJECTIVE

To investigate the possible bone changes in female patients with systemic lupus erythematosus (SLE) induced by long-term administration of Tripterygium Wilfordii Hook. F (TW).

METHODS

70 female SLE patients were divided into 4 groups according to their drug history: SLE disease control group, corticosteroids treatment group, TW treatment group, and both corticosteroids and TW treatment group. Bone mineral density (BMD) of the lumbar spine 2-4 and biochemical markers of bone turnover were studied.

RESULTS

Long-term administration of TW could significantly decrease BMD levels in female SLE patients (P < 0.05). The patients receiving TW for more than 5 years had significantly lower BMD levels compared with those for less than 5 years. The degree of decreased BMD induced by TW was less severe compared with that of prednisone. No significant differences were observed in the biochemical markers of bone turnover among four groups (P > 0.05).

CONCLUSION

Long-term administration of TW could decrease BMD levels in women. Osteoporosis may be an important problem for SLE patients treated with TW.

[Treatment of acute lymphoblastic leukemia by autologous stem cell transplantation: an analysis of 30 cases]

OBJECTIVE

To evaluate the clinical outcome of autologous stem cell transplantation (ASCT) in acute lymphoblastic leukemia (ALL) and the affected factors.

METHODS

Data of 30 ALL patients received ASCT in our hospital between July 1987 and December 1997 were retrospectively analyzed. Twenty-four of them were in the first complete remission (CR(1)) and six in the second complete remission (CR(2)) or early relapse (ER). Conditioning regimens were CTX 120 mg/kg + single total body irradiation 9 - 10 Gy (sTBI) or Bu 16 mg/kg of Mel 140 - 180 mg/m(2) + Ara-c 2 - 4 g/m(2).

RESULTS

All patients reconstituted hematopoiesis. The median follow-up duration was 504 (18-3043) days. Transplant-related mortality was 10%. The probabilities of 3 year disease-free survival (DFS) for ALL in CR(1) and CR(2) were 67.7% +/- 10.3% and 16.7% +/- 15.2%, respectively (P = 0.00547); the 3 year DFS was significantly better with posttransplant treatment than without it (92.3% +/- 7.4% vs 50.0% +/- 17.7%, P = 0.0130).

CONCLUSION

Acute lymphoblastic leukemia patients without HLA-matched related donor are recommended for ASCT in CR(1). To reduce relapse and improve the outcome, adoptive immunotherapy or maintenance chemotherapy should be given after ASCT.

Basal lamina of avian ovarian follicle: influence on morphology of granulosa cells in-vitro

Experiments were conducted to determine the influence of basal lamina on the morphology of ovarian granulosa cells in vitro. Pure and intact basal lamina was isolated from the large preovulatory follicles of the chicken ovary and designated basal lamina of avian ovarian follicle (BLAOF). Examination of the isolated basal lamina with electron microscope revealed an ultrastructure that is similar to that of basal lamina in the intact ovarian follicle. Pieces of the intact basal lamina were attached to the bottom of 32 mm culture dishes (BLAOF-coated dishes) in which differentiated granulosa cells isolated from the largest preovulatory follicle or undifferentiated granulosa cells isolated from immature small yellow chicken ovarian follicles were cultured; uncoated dishes served as controls. Granulosa cells incubated on intact basal lamina assumed spherical shape, whereas granulosa cells incubated directly on plastic in control dishes became highly flattened. Interestingly, granulosa cells that attached to plastic close to BLAOF (in BLAOF-containing dishes) became rounded. The storage of BLAOF-coated culture dishes at 4 degrees C for 2 years had no apparent effect on its ability of the matrix material to induce changes in granulosa cell shape. Some components of the basal lamina could be solubilized with guanidine-HCl alone (fraction 1; 90-95% of total protein in BLAOF) with the remaining components solubilized with beta-mercaptoethanol containing guanidine-HCl (fraction 2; 5-10% of total protein in BLAOF). Differentiated and undifferentiated chicken granulosa cells became rounded when incubated in fraction 1-pre-coated wells; whereas those incubated directly on plastic in control wells were flattened. Similarly, when fraction 1 of solubilized basal lamina was added as liquid to incubation mixture, it caused both differentiated and undifferentiated granulosa cells to assume spherical shapes. The storage of fraction 1-coated culture dishes at 4 degrees C for 12 or more months had no apparent effect on its ability to influence granulosa cell shape. Fraction 1-induced changes in granulosa cell shape were similar to those observed for complete and intact basal lamina (BLAOF). These findings demonstrate that intact homologous basal lamina (BLAOF) or its solubilized (fluidized) form can induce normal (in vivo) morphology in granulosa cells. It is suggested that BLAOF or its solubilized form can be used to culture cells in experiments designed to examine the influence of the natural basal lamina microenvironment on cellular behavior and function.

Cytoplasmic domains of GpIbalpha and GpIbbeta regulate 14-3-3zeta binding to GpIb/IX/V

Shear stress causes the platelet glycoprotein (Gp) Ib/IX/V to bind to von Willebrand factor, resulting in platelet adhesion. GpIb/IX/V also functions to stimulate transmembranous signaling, leading to platelet activation and the expression of a ligand-receptive GpIIb-IIIa complex. The highly conserved cytoplasmic domain of GpIbalpha binds directly to a dimeric 14-3-3 adapter protein zeta isoform. To explore structural determinants of GpIb/IX/V binding to 14-3-3zeta, the authors examined 14-3-3zeta interactions with GpIbalpha and GpIbbeta in heterologous cells and platelets. Truncations of GpIbalpha at amino acid 542 or 594, or deletions of residues 542 through 590, inhibited binding of 14-3-3zeta. Deletion of GpIbalpha from Trp(570) to Ser(590) eliminated 14-3-3zeta binding, and deletion of the sequence from Arg(542)-Trp(570) enhanced binding of 14-3-3zeta to GpIbalpha. All GpIbalpha mutations that eliminated GpIbalpha binding to the GST-14-3-3zeta fusion protein also eliminated GpIbbeta binding to the fusion protein. Forskolin treatment of Chinese hamster ovary cells expressing wild-type GpIbalpha/beta/IX resulted in the phosphorylation of GpIbbeta associated with enhanced binding of GpIbbeta to GST-14-3-3zeta fusion protein and increased 14-3-3zeta coimmunoprecipitated with GpIbalpha. When intact human platelets aggregated in response to 90 dynes/cm(2) shear stress, 14-3-3zeta disassociated from GpIbalpha. Prostacyclin treatment of platelets inhibited shear stress-induced aggregation and the release of 14-3-3zeta from GpIbalpha. These data demonstrate that amino acid residues in the cytoskeletal interaction domains of GpIbalpha regulate 14-3-3zeta binding to GpIbalpha/beta/IX, and suggest that protein kinase A-dependent phosphorylation of GpIbbeta enhances 14-3-3zeta binding to the GpIb/IX/V complex in human platelets. (Blood. 2000;95:551-557)

Spatiotemporal structure of isodiffracting ultrashort electromagnetic pulses

We present a model of isodiffracting single-cycle and few-cycle ultrashort electromagnetic pulses. The model is based on exact solutions of the time-dependent paraxial wave equation with space-time coupling effects included. The spatiotemporal structure of these pulses is characterized by a scaling parameter which relates off-axis pulse shapes to the axial temporal waveforms. Depending on the spectrum a pulse may transform itself from a single-cycle pulse to a multicycle pulse along the radial coordinate. This model is also used to describe recirculating pulses in a curved mirror cavity resonator. The Gouy phase shift contributes an absolute phase that results in a pulse-to-pulse temporal instability.

Isolation and mapping of rFUS6, a rice orthologue of Arabidopsis thaliana FUS6

COP9 complex is one of the most important components that act in repressing photomorphogenesis in Arabidopsis thaliana. FUS6 has been identified as one of eight subunits of the COP9 complex in Arabidopsis. Using Arabidopsis Fus6 cDNA as a probe, we screened a rice root cDNA library and a rice genomic library. A 1730-bp cDNA was obtained, which has an open reading frame corresponding to 441-amino-acid. This 441 amino acids putative protein has 67% identity with Arabidopsis COP11/FUS6 (AtFUS6) and 40% identity with human GPS1, an AtFUS6 orthologue. So we designated this novel gene as rFUS6. The 6.2-kb genomic sequence of rFUS6 was also obtained. Sequence comparison showed that the rFUS6 gene had six exons and five introns. Sequence inspection of the 5'-flanking region revealed the presence of some potential light-regulated cis-elements such as a G-box, GT-1 binding sites, and a TGACG motif. Southern hybridization with rice total DNA showed that rFUS6 was perhaps a single copy gene. The rFUS6 locus was mapped by hybridization with a rice BAC library membrane and the results showed that rFUS6 had a locus at 16.3 cM of chromosome 1.

The effect of electroacupuncture on auditory P300 potential in mongolism cases

In treating children with mongolism (Down's syndrome) with electroacupuncture, the latent period of P3 is shortened, which shows that the cerebral reaction to external stimulus in classification, encoding and recognition is accelerated. Along with the elevated P3 amplitude, the cerebrum is more capable of processing the external information, showing improvement of the mental state.

Identification and analysis of the major metabolites of cocaine in meconium

A gas chromatographic-mass spectrometric (GC-MS) method was used for the simultaneous analysis of cocaine and its metabolites (norcocaine, benzoylecgonine, norbenzoylecgonine, ecgonine methylester, cocaethylene, and the o-, m, and p-hydroxy derivatives of cocaine and benzoylecgonine) in meconium specimens collected from newborns prenatally exposed to the drug in an effort to determine which of these metabolites are more relevant in the confirmation of immunoassay-positive specimens. Significant metabolites included benzoylecgonine and its m- and p-hydroxy derivatives. Reanalysis of immunoassay-positive meconium specimens that previously failed to confirm by GC-MS for benzoylecgonine revealed that the GC-MS confirmation rate could be substantially enhanced by inclusion of m- and p-hydroxybenzoylecgonine in the analysis along with benzoylecgonine. Several specimens were found to be positive for hydroxylated derivative(s) in the absence of benzoylecgonine itself.

GC-MS determination of flunitrazepam and its major metabolite in whole blood and plasma

A gas chromatography-mass spectrometry method was developed for the analysis of flunitrazepam (FN) and its major metabolite, 7-amino-flunitrazepam (7-amino-FN), in both plasma and whole blood. The method was based on acid hydrolysis of the samples after dilution with HPLC water followed by extraction and derivatization (heptafluorobutyrate) of the resulting benzophenones. Analysis of plasma and whole blood samples from subjects administered 2-mg doses of FN showed that FN was only detected in whole blood (LOD 5 ng/mL) and not in plasma. However, 7-amino-FN was detected in both plasma and whole blood, although the levels were much higher in plasma. 7-Amino-FN was detected for the entire period of specimen collection (12 h), but FN was only detected in whole blood for 4 h after ingestion with peak levels after 1 h.

Relationship of beta-glucuronidase to differentiation and invasion of human colorectal carcinoma

OBJECTIVE

To investigate the relationship between beta-glucuronidase and tumor differentiation and invasion in human colorectal carcinoma.

METHODS

The expression of beta-glucuronidase in human colorectal carcinoma tissue was determined by streptavidin-peroxidase immunohistochemical method. Four human colorectal carcinoma cell lines were analysed for beta-glucuronidase in the medium by spectrophotometry method.

RESULTS

Compared with well differentiated colorectal carcinomas, beta-glucuronidase expression was higher in poorly differentiated tumors. An association was found between beta-glucuronidase overexpression in colorectal carcinoma and more advanced tumor Dukes' stage (P < 0.05). With increasing maximum depth of invasion, tumors more frequently show higher beta-glucuronidase expression (P < 0.05). The analysis of colorectal carcinoma cell lines for beta-glucuronidase showed that low levels of beta-glucuronidase (activity range, 1.29 to 1.96 micrograms/10(6) cells per hour) were associated with the well differentiated cell lines which have low invasiveness (CX1, CCL187), and this was in contrast to the elevated level of the enzyme (2.46 to 2.73 micrograms/10(6) cells per hour) present in the medium derived from the poorly differentiated cells with high invasiveness (CCLI227, CCL228) (P < 0.05).

CONCLUSIONS

Poorly differentiated human colorectal carcinoma cells could synthesize more beta-glucuronidase, enhance local invasion. Immunohistochemical staining for beta-glucuronidase might be helpful to diagnosing the differentiation degree and invasiveness of human colorectal carcinomas, and the secreted beta-glucuronidase might provide a useful measurement of the differentiation degree and invasiveness of cultured human colorectal carcinoma cells.

Experimental studies on affinity chromatography in an electric field

A multicompartment electrolyzer, which has been used for preparative electrophoresis [Z. Liu, Z. Huang, J.-Y. Cong, et al., Sep. Sci. Technol. 31 (1996) 427], is applied for carrying out affinity chromatography in an alternating electric field. The effect of electric field strength on the adsorption and desorption characteristics is experimentally examined with human serum albumin and Blue Sepharose Fast Flow as a model system. It is shown that the existence of an electric field leads to a significant change in the adsorption capacity of the blue dye, which may be used for establishing a preferential adsorption to achieve a high resolution. The adsorption speed increases slightly with respect to the increase of electric field strength, while adsorption capacity in the presence of an electric field is independent of the electric field strength. Different elution behavior is observed as function of adsorption condition and a high recovery of the adsorbed protein is obtained when the adsorption is carried out in the presence of an electric field.

[Comparison of clinical outcome between allogeneic peripheral blood stem cell transplantation and bone marrow transplantation]

OBJECTIVE

To compare the clinical outcome of allogeneic peripheral blood stem cell transplantation(PBSCT) with that of bone marrow transplantation(BMT).

METHODS

Twenty-six patients received allo-BMT and 24 received allo-PBSCT in our hospital between August 1991 and September 1998. Conditioning regimens were CY 120 mg/kg plus STBI 9-10 Gy or BU 16 mg/kg or Mel 140-160 mg/m2 plus CY 120 mg/kg.

RESULTS

Twenty-three patients of PBSCT and 24 of BMT group engrafted successfully. The median follow-up duration was 352(19-745) days for the PBSCT group and 546(19-2,329) days for the BMT group. Transplant-related death was 4(16.7%) patients in the PBSCT and 7(26.9%) in BMT group (P = 0.38). Three(12.5%) patients in PBSCT and 5(19.2%) in BMT group relapsed(P = 0.27). The 2-year probabilities of disease-free survival(DFS) for PBSCT and BMT group were (67.9 +/- 11.3)% and (57.7 +/- 9.7)%, respectively(P = 0.24). aGVHD occurred in 6(25%) patients in the PBSCT and 6 (23.1%) in the BMT group (P = 0.624), while cGVHD did in 13(56.5%) and 1 (3.85%), respectively (P = 0.0002).

CONCLUSION

The clinical outcome of allo-PBSCT is similar to allo-BMT, except for a higher incidence of cGVHD.

[Judging the date of Neijing (Inner Canon) through study on semantic changes]

In the pre - Qin literature, the characters "ti", "pi", "nian" refer to "tear", "beast skin" and "year" respectively and it became "nasal discharge", "man's skin" and "age" respectively in the Han dynasty, which never appeared in the pre - Qin period. By studying the semantic changes in books of different times, the meanings of the above 3 characters, that frequently occurred in Neijing, are identical with those books of the Han dynasty. Hence, it can be concluded that Neijing can only be completed not early than the Han dynasty.

[Pure red cell aplasia after allogeneic peripheral blood stem cell transplantation: a case report and literature review]

OBJECTIVE

To report a case of post-allogeneic peripheral blood stem cell transplantation (allo-PBSCT) pure red cell aplasia(PRCA) and the treatment outcome.

METHODS

A patient with acute non-lymphoblastic leukemia(M2a) was treated with allo-PBSCT. His post-PBSCT PRCA was treated with plasmapheresis(2-3 times weekly) and Epo(3,000 U/day, subcutaneously).

RESULTS

Reticulocyte count (Ret) recovered to 0.01 at day +131 and hemoglobin reached 110 g/L at day +154. Erythroid cells in the bone marrow recovered to 0.25, and BFU-E and CFU-E within normal range. This normalized hematopoiesis remained for over 5 months after the cessation of Epo.

CONCLUSION

Post allo-PBSCT PRCA can be successfully treated with plasma exchange and Epo.

Prolonged xenograft survival of islets infected with small doses of adenovirus expressing CTLA4Ig

BACKGROUND

Systemic administration of the inhibitor of costimulation, CTLA4Ig, has been shown to prolong islet graft survival. The purpose of this study was to compare local and systemic expression of murine CTLA4Ig in transplants of rat islets into mice.

METHODS

Murine CTLA4Ig was made by joining two polymerase chain reaction products, the extracellular portion of CTLA4 and the Fc portion of IgG2a. Recombinant adenovirus expressing CTLA4Ig (AdCTLA4Ig) was generated using the strategy of Cre-lox recombination. Isolated rat islets infected with AdCTLA4Ig at multiplicities of infection (MOIs) ranging from 0.1 to 10 were transplanted into streptozocin diabetic male B6AF1 mice. Control islets were mock infected or infected with AdLacZ or AdsIg, a recombinant adenovirus expressing only the Fc portion of IgG2a. Also, AdCTLA4Ig and control viruses were injected intramuscularly into mouse transplant recipients at the time of islet transplantation to provide CTLA4Ig systemically.

RESULTS

Control islets transplanted into diabetic mice were rejected in 13-17 days. Islets infected with AdCTLA4Ig had dose-dependent prolongation of graft survival. Prolonged survival was even found with very low MOIs of 0.1 and 0.5, with survivals of 24+/-4.2 and 25+/-2.2 days, respectively. Survival with an MOI of 10 was 39+/-8.7 days. With intramuscular injection, no prolongation was found at the lowest relative MOIs of 0.2 and 1, but there was dose-dependent prolongation of graft survival with larger doses. At the highest relative MOI of 400, survival was prolonged to 58+/-10 days.

CONCLUSIONS

Rat islets infected with AdCTLA4Ig transplanted into mice had prolonged graft survival. Prolonged survival with MOIs as low as 0.1 and 0.5 indicates that only a minority of islet cells need to express CTLA4Ig to exert an effect. Moreover, the results suggest that the improved islet graft survival is due to a local influence of CTLA4Ig.

The glycoprotein Ib/IX complex regulates cell proliferation

The glycoprotein (Gp) Ib/IX complex contains three transmembranous leucine-rich repeat polypeptides (GpIbalpha, GpIbbeta, and GpIX) that form the platelet von Willebrand factor (vWF) receptor. GpIb/IX functions to effect platelet adhesion, activation, and aggregation under conditions of high shear stress. GpIb/IX is expressed late in the ontogeny of megakaryocytes, the precursor cell that releases platelets when it reaches its terminal stage of differentiation. Because signal pathways can be reused at different stages of development by integration with different effector pathways and because cellular adhesion through other receptor families often modulates cell growth, the hypothesis that GpIb/IX regulates cell growth was investigated. The surface expression of recombinant GpIbalpha decreases the proliferation of transduced CHO cells. GpIbalpha causes growth arrest in the G1 phase of the cell cycle associated with the induction of the cyclin-dependent kinase inhibitor p21. G1 arrest induced by recombinant GpIbalpha in heterologous cells requires signaling through the 14-3-3zeta binding domain of GpIbalpha and is partially dependent on its engagement by the extracellular ligand vWF. Growth arrest induced by the expression of recombinant GpIb/IX is followed by apoptosis of the transduced cells. The endogenous expression of GpIbalpha in human hematopoietic cells is associated with decreased proliferation. These results suggest that the expression of the GpIb/IX complex regulates megakaryocyte growth.

Preparation and Morphology Studies of Core-Shell Type Waterborne Polyacrylate-Polyurethane Microspheres

Core-shell type waterborne polyacrylate-polyurethane microspheres in which polyurethane acts as the shell and acrylic polymer as the core were prepared. Hydroxyethyl acrylate and adipic dihydrazide were used as cross-linking agents introduced to the ends of the shell molecular chains, and two kinds of cross-linked structures between the core and the shell were formed. The photon correlation spectroscopy studies indicate that all the microspheres present continuous particle-size distributions and their mean particle sizes are smaller than 200 nm. The transmission electron photographs reveal that there are obvious core-shell structures for the noncross-linked type microsphere particles and different cross-linked networks between the core and shell for the two kinds of cross-linked type microsphere particles. These microspheres possess excellent storage stability, water resistance, and coating properties. Copyright 1999 Academic Press.

[Study on masticatory muscles and tooth long axis of miniature pigs]

OBJECTIVE

The similarities of masticatory muscles and teeth orientations between miniature pigs and human beings were studied in order to evaluate the use of miniature pigs in oral biomechanics research.

METHODS

By means of anatomy, the shapes, start-stop points and orientations of muscle of major masticatory muscles of miniature pigs were measured. Inclination of upper and lower teeth long axis was studied with lateral xray film of mandibles.

RESULTS

The main masticatory muscles of miniature pigs include masseter muscle, temptory muscle, lateral pterygoid muscle, medial pterygoid muscle and zygomaticomandibular muscle. The angles of masticatory muscles and base plane are 63.9 degrees in massater muscle, 114.55 degrees in temple muscle, 64.4 degrees in medial pterygoidp muscle. The long axises of miniature pigs teeth are 6.1 degrees in the upper first molar, 6.5 degrees in the lower first molar, 7.3 degrees in the upper third premolar, 3.8 degrees in the lower third premolar.

CONCLUSION

The masticatory muscles of miniature pigs are similar with human being in the shape, start-stop point and orientation of muscle force. The third premolar and the first molar of miniature pigs inclinate mesially, and are similar with the first premolar and the first molar of the human beings. Miniature pigs can be used as an animal models which can explain some problems of gnathostomatic system of human beings.

Phylogenetic position of the kinetoplastids, Cryptobia bullocki, Cryptobia catostomi, and Cryptobia salmositica and monophyly of the genus Trypanosoma inferred from small subunit ribosomal RNA sequences

Phylogenetic relationships within the kinetoplastid flagellates were inferred from comparisons of small-subunit ribosomal RNA gene sequences. These included three new gene sequences from Cryptobia bullocki, (2091 bp), Cryptobia catostomi (2090 bp), and Cryptobia salmositica (2091 bp). Trees produced using maximum parsimony and distance-matrix methods (least squares and neighbor-joining) demonstrated with strong bootstrap support, that the kinetoplastids are a monophyletic group divided into two major lineages consistent with the two suborders, Trypanosomatina and Bodonina. Within the trypanosomatid clade, the genus Trypanosoma is a monophyletic group that divides into two groups, the salivarian trypanosomes and the stercorarian trypanosomes. Dimastigella and Rhynchobodo, currently classified in the Bodonina, are basal to the trypanosomatid-bodonid clade, suggesting that the suborder Bodonina is paraphyletic. Further, Trypanoplasma borreli grouped within the Cryptobia clade, and was more closely related to C. salmositica than to either C. bullocki or C. catostomi. This new molecular evidence, coupled with morphological similarities of the two genera, again calls into question the validity of the genus Trypanoplasma.

[Analysis of patients survived over ten years after resection of gastric cardia carcinoma]

OBJECTIVE

To investigate factors affecting long-term survival in patients with resected gastric cardia cancer.

METHODS

Survival was analyzed retrospectively in 584 patients with gastric cardia carcinoma who received tumor resection from 1964 through 1982.

RESULTS

The 10-year survival rate was 17.1%. The major factors influencing survival were clinical staging, degree of differentiation, gross tumor type and size (P < 0.05) and status of lymph node metatasis (P < 0.01). Residual tumor at resection edge and tumor thrombi did not significantly affect survival, nor did sex/age, and course of the disease.

CONCLUSION

Early detection, early diagnosis and early surgical resection are the key to improve 10-year survival of patients with resected cancer of the gastric cardia. Why residual tumor left at the resection edge and the presence of tumor thrombi do not influence survival needs to be further studied.

Killing effect of interleukin-2 and interferon-alpha activated leukemic bone marrow in remission on K562 leukemic cells

OBJECTIVE

To evaluate the killing effect of interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) activated bone marrow cells on K562 cells.

METHODS

Semi-solid colony and 3H-TdR incorporating method were used.

RESULTS

Bone marrow from leukemia patients in remission was activated in vitro with IL-2 for 3 days. The activated bone marrow (ABM) displayed killing effects of 0.31-2.30 logs on K562 cells. This killing effect was further increased to 0.30-3.15 logs when IFN-alpha added with IL-2 to the marrow for activation. IL-2 alone or in combination with IFN-alpha showed no inhibition of CFU-GM and K562 cells. Compared with IL-2 or IFN-alpha alone, the combination of the two cytokines could more effectively maintain the killing effect of ABM on leukemic cells.

CONCLUSIONS

IFN-alpha can augment the purging effect of IL-2 ABM and combination of the two cytokines can effectively maintain the cytotoxicity of ABM.

GC/MS analysis of m-hydroxybenzoylecgonine in urine. Forensic implication in cocaine use

m-Hydroxybenzoylecgonine (m-OH-BE) and d3-m- hydroxybenzoylecgonine (d3-m-OH-BE) have been synthesized, and a GC/MS procedure with d3-m-OH-BE as internal standard has been developed. Among 24 human urine specimens that were positive for BE, all of them have shown detectable levels of m-OH-BE with 75% of the specimens exceeding the LoQ (5 ng/mL), compared with only 50% of the specimens containing detectable levels of EME. The presence of m-OH-BE in urine suggested that this metabolite may serve as a valuable marker of cocaine use in addition to BE and EME.

Acquisition and transmission of the agent of human granulocytic ehrlichiosis by Ixodes scapularis ticks

The purpose of the present study was to investigate the transmission of a human isolate of the agent of human granulocytic ehrlichiosis (HGE agent) from infected mice to larval ticks and to examine the population kinetics of the HGE agent in different stages of the tick life cycle. The HGE agent was quantitated by competitive PCR with blood from infected mice and with Ixodes scapularis ticks. The median infectious dose for C3H mice was 10(4) to 10(5) organisms when blood from an infected severe combined immunodeficient mouse was used as an inoculum. Uninfected larval ticks began to acquire infection from infected mice within 24 h of attachment, and the number of HGE agent organisms increased in larval ticks during feeding and after detachment of replete ticks. Molted nymphal ticks, infected as larvae, transmitted infection to mice between 40 and 48 h of attachment. Onset of feeding stimulated replication of the HGE agent within nymphal ticks. These studies suggest that replication of the HGE agent during and after feeding in larvae and during feeding in nymphs is a means by which the HGE agent overcomes inefficiencies in acquisition of infection by ticks and in tick-borne transmission to mammalian hosts.

Transcatheter embolization of biopsy-related vascular injury in the transplant kidney: immediate and long-term outcome

PURPOSE

To assess the effect of transcatheter embolization for treatment of biopsy-related vascular injury in renal allografts, specifically evaluating technical success, clinical benefit, and long-term effect on renal function.

MATERIALS AND METHODS

A retrospective review was performed of all postbiopsy renal allograft vascular injuries referred for embolization during a 113-month period. The likelihood of a prolonged detrimental effect on allograft function was estimated from observed variation in serum creatinine levels before and after the procedure.

RESULTS

Embolic therapy with use of metallic coils and superselective technique was performed in 21 renal transplant patients. Technical success was achieved in 95% of cases. There were no serious complications. Eradication of the clinical sign or symptom prompting referral was seen in 15 of 17 (88%) patients. Eleven of 19 (58%) patients analyzed demonstrated no evidence of a long-term detrimental effect on allograft function. A detrimental effect was possibly present in six of 19 (32%) patients, and probable in only two of 19 (10%) patients.

CONCLUSIONS

Transcatheter embolization can be an appropriate and effective therapeutic choice for biopsy-related renal allograft vascular injury.

[Outcome of autologous bone marrow transplantation in 73 patients with acute leukemia]

OBJECTIVE

To evaluate the clinical outcome of autologous bone marrow transplantation(ABMT) in acute leukemias.

METHODS

Data of 73 acute leukemia patients performed ABMT in our hospital from October 1986 to December 1997 were retrospectively analyzed. The median age was 25.5(9-48) years. Forty-three of them were ANLL [CR1 35, CR2 or early relapse (ER)8], 30 were ALL (CR1 25, CR2 or ER 5). Conditioning regimens were CTX 120 mg/kg + STBI 9-10 Gy or Bu 16 mg/kg or Mel 160-180 mg/m2 + Ara-C 4 g/m2.

RESULTS

All patients engrafted successfully. The median follow-up duration was 806 (32-3400) days. The 3-year probabilities of disease-free survival (DFS) for ANLL and ALL in CR1 were 54.9 +/- 7.7% and 67.0% +/- 10.6%, respectively, and the probabilities of relapse were 39.3% +/- 9.3% and 23.7% +/- 10.6%, respectively.

CONCLUSION

To decrease relapse and increase DFS, patients with acute leukemia in CR1 who have no HLA-matched related donor are recommended for ABMT.

delta 9-THC metabolites in meconium: identification of 11-OH-delta 9-THC, 8 beta,11-diOH-delta 9-THC, and 11-nor-delta 9-THC-9-COOH as major metabolites of delta 9-THC

Gas chromatography-mass spectrometry (GC-MS) analysis of meconium specimens screening positive for cannabinoids by the EMIT 20 Assay showed a low confirmation rate for 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (THCCOOH). A study was designed to investigate the possible contribution of other delta 9-tetrahydrocannabinol (THC) metabolites, including glucuronides, to the overall response of the EIA. delta 9-THC-glucuronide was synthesized in order to develop the most efficient procedure for hydrolysis of glucuronides in meconium. Procedures were developed for the extraction and GC-MS analysis of delta 9-THC, 11-OH-delta 9-THC, 8 alpha- and 8 beta-OH-delta 9-THC, 8 beta,11-diOH-delta 9-THC, and THCCOOH, after enzymatic hydrolysis of meconium extracts. It is concluded that enzymatic hydrolysis of meconium extracts is necessary for efficient recovery of delta 9-THC metabolites; delta 9-THC and its 8-OH metabolite(s) are basically absent in meconium specimens; and 11-OH-delta 9-THC and 8 beta,11-diOH-delta 9-THC contribute significantly to the immunoassay response of meconium extracts. Analysis of several meconium specimens that screened positive for cannabinoids but failed to confirm for THCCOOH showed significant amounts of 11-OH-delta 9-THC and 8 beta,11-diOH-delta 9-THC. Therefore, GC-MS confirmation of cannabinoids in meconium should include analysis for these two metabolites in addition to THCCOOH.

[Effects of mifepristone on the serum nitric oxide level and uterine blood flow in early pregnant women]

OBJECTIVE

To study the effects of mifepristone on serum nitric oxide (NO) level and uterine blood flow in early pregnant women.

METHODS

Serum NO concentrations of 58 early pregnant women and 15 normal nonpregnant women were measured by a copper-coated cadmium reduction method, and uterine artery and trophoblastic blood flow were determined by color doppler flow imaging (CDFI). The ultrastructure of villi and decidua were studied under electron microscopy.

RESULTS

Compared with nonpregnant women, serum NO concentration was significantly higher in early pregnant women(P < 0.01). After administration of mifepristone, serum NO level was significantly decreased, resistance index(RI) and systolic to diastolic ratio(S/D) ratio of uterine artery and trophoblastic blood flow were significantly higher than that of normal early pregnancy(P < 0.05).

CONCLUSION

Mifepristone may exert effects on uterine blood flow by decreasing serum NO level.

[Synthesis and anti-Candida albicans properties of L-4-oxalysine-N3-4-methoxyfumaroyl-L-2,3-diaminopropanoic-containing peptide analogues]

In order to improve the inhibitory activity of L-4-oxalysine(abbreviated as I-677) against clinically important pathogen Candida albicans, double-warheads peptide analogues containing I-677 and N3-4-methoxyfumaroyl-L-2,3-diaminopropanoic acid(FMDP) were designed based on the concept of "Illicit Transport" and peptide transport specificities of C. albicans. One compound of I-677-FMDP and seven compounds of I-677-AA-FMDP(AA = Nva, Leu, Val, Phe, Pro, D-Pgly, D, L-p-Cl-Phe) were synthesized and examined for antifungal activities. The results of anti-Candida albicans test in vitro of these double- warheads peptide analogues containing I-677 and FMDP showed very high activities against Candida albicans. The molar MIC (molar minimum inhibitory concentration) ratio of free I-677 to I-677-AA-FMDP is 40-770 and that of FMDP is 60-1130. The values of molar MIC of I-677-AA-FMDP varied from 6.56 x 10(-9) mol.disk-1 to 3.5 x 10(-10) mol.disk-1. The results of competitive antagonism studies indicated that I-677-AA-FMDP were transported into Candida albicans cells by the di-tripeptide permease and subsequently hydrolyzed by intracellular peptidases, releasing free I-677 and FMDP inside cells. The result of antienzymic degradation test in vitro of I-677-FMDP showed that compound I-677-FMDP was resistant to the hydrolysis by carboxypeptidase A.

Humoral immunity to Borrelia burgdorferi N40 decorin binding proteins during infection of laboratory mice

A Borrelia burgdorferi N40 genomic expression library was screened with serum from actively infected mice to identify gene products that elicit protective immunity. A clone that contained a putative bicistronic operon containing two genes that encoded 20- and 22-kDa lipoproteins was identified and sequenced. These genes showed homology with the genes encoding decorin binding proteins DbpB and DbpA, respectively, of B. burgdorferi 297 and B31. N40-dbpA DNA hybridized with B. burgdorferi N40 DNA on a single 48-kb linear plasmid. Homologous genes could be amplified under various degrees of stringency by PCR or hybridized by Southern blotting from B. burgdorferi sensu stricto N40 and B31, and from B. burgdorferi sensu lato PBi and 25015, but not PKo. Recombinant N40-DbpB and N40-DbpA were reactive with antibody in serum from infected mice, and serum was more reactive against N40-DbpA than against B. burgdorferi N40 recombinant P39, OspC, or OspA. Sera from mice infected with B. burgdorferi sensu lato strains PKo and PBi were weakly reactive against N40-DbpB and N40-DbpA, and sera from mice infected with 25015 were moderately reactive, compared to sera from mice infected with B. burgdorferi N40. Hyperimmunization of mice with N40-DbpA, but not N40-DbpB, induced protective immunity against syringe challenge with cultured B. burgdorferi N40. DbpA may therefore be one of the antigens responsible for eliciting protective antibody known to exist in serum from infected mice. DNA amplification and serology suggest that DbpB and DbpA are likely to have homologs throughout the B. burgdorferi sensu lato family, but they are likely to be heterogeneous.

Identification of carbohydrates on the surface membrane of pathogenic and nonpathogenic piscine haemoflagellates, Cryptobia salmositica, C. bullocki and C. catostomi (Kinetoplastida)

Carbohydrates and protein glycoconjugates on the cell membranes of Cryptobia salmositica, C. bullocki and C. catostomi were analyzed using 13 highly purified lectins (unlabelled or digoxigenin/biotin labelled). No agglutinations were observed with C. salmositica, C. bullocki and C. catostomi using lectin TPA (Tetragonolobus purpureas agglutinin, for alpha-L-fucose). C. salmositica was agglutinated by 3 of 12 lectins [Con A, for alpha-man and alpha-D-glc; PSA, for alpha-man; PWM, for (glcNAc)3], while C. bullocki was agglutinated by 8 lectins and C. catostomi was agglutinated by 10 lectins. Glycoconjugate analysis with digoxigenin or biotin labelled lectins showed a species-specific staining pattern in pathogenic and nonpathogenic Cryptobia spp. The nonpathogenic C. catostomi had the strongest reaction. These results indicate that the surface carbohydrate residues and glycoconjugate compositions on Cryptobia spp. are different between species they may be related to the virulence of the parasite.

Inhibition of growth of malignant rat prostate tumor cells by restoration of fibroblast growth factor receptor 2

A loss of expression of fibroblast growth factor (FGF) receptor 2 IIIb (FGFR2IIIb), which responds to stroma-derived FGF, accompanies progression of premalignant androgen-responsive rat prostate tumor epithelial cells to the malignant phenotype. Concurrently, the level of FGFR2 gene expression is reduced and lost altogether in over 30% of cells, whereas all malignant cells abnormally express FGFR1, which is normally confined to stromal cells (S. Feng et al., Cancer Res., 57:5369-5378, 1997). To determine the relative roles of the FGFR2 and FGFR1 kinases in growth of malignant cells, we transfected malignant prostate epithelial cells with the wild-type FGFR2IIIb kinase and an artificial chimeric construct (FGFR2IIIb/R1) composed of the FGFR2IIIb ectodomain and the FGFR1 kinase domain. Population growth kinetics, in both the absence and presence of FGF-7, which binds only the FGFR2IIIb ectodomain, were then examined in the transfected cell populations. In contrast to the untransfected malignant tumor cells and those expressing the FGFR2IIIb/R1 chimera, FGF-7 caused a dose-dependent net inhibition of the population growth rates of cells expressing the full-length FGFR2IIIb kinase. The results suggest that although the FGFR2 kinase can mediate positive mitogenic effects, it mediates a net restriction on the growth of prostate tumor epithelial cells relative to FGFR1. Highly malignant prostate tumor cells, which have lost the FGFR2 tyrosine kinase, retain the cellular response mechanisms to it. Restoration of the FGFR2 kinase to malignant tumors that are refractory to treatment may present a new avenue for gene therapy.

Granulocytic ehrlichiosis in the laboratory mouse

C3H mice that were inoculated with ehrlichiae isolated from a patient with human granulocytic ehrlichiosis (HGE) developed anemia and leukopenia, but by day 24, they returned to normal values. Granulocytic morulae were present in peripheral blood and spleen smears on days 5 and 10, and there was a reduction in morulae on day 17. Ehrlichiae were present in HL-60 cell cultures of blood and spleen from all mice at all intervals. Pathogenicity, but not infectivity, waned with mouse passage but could be resurrected by SCID mouse passage. Various methods were tested for their relative sensitivity in detecting infection: blood smears, HL-60 cell cultures, polymerase chain reaction (PCR) amplification of a 16S recombinant DNA target, and a mouse infectivity assay. All assays detected the HGE agent in blood during early infection, but PCR and the mouse infectivity assay were most sensitive during late infection. Xenodiagnosis demonstrated that mice remain persistently infected through 55 days.

Gouy shift and temporal reshaping of focused single-cycle electromagnetic pulses

We discuss exact solutions of Maxwell's equations that describe the evolution of single-cycle electromagnetic pulses. The solutions are applied to recent observations of the diffraction transformation of terahertz pulses. In particular, we elucidate the role of the Gouy shift in the temporal reshaping and polarity reversals of single-cycle terahertz pulses.

Characterization of a 200 kDa glycoprotein (Cs-gp200) on the pathogenic piscine haemoflagellate Cryptobia salmositica

The 200 kDa antigenic doublet of the pathogenic haemoflagellate Cryptobia salmositica Katz, 1951, was detected using a monoclonal antibody (MAb-001) in 1-dimensional SDS-PAGE. This antigenic doublet is a glycoprotein since it was susceptible to both protease K and to sodium m-periodate oxidation and is designated Cs-gp200. It has a PI (isoelectric point) value of about 5.5 (using 2-dimensional gel electrophoresis). It migrated faster under reducing conditions than under nonreducing conditions and was partitioned into the aqueous phase in Triton X-114 phase separation. It is a secretory-excretory product since it was detected in a non-protein culture medium with C. salmositica. These results suggest that the Cs-gp200 is a glycoprotein consisting of carbohydrate determinants and conformational polypeptide with internal disulphide bonds. It is a hydrophilic antigen, is a secretory product of the parasite, and plays a important role in antibody elicitation in immunized fish.

Direct activation of inward rectifier potassium channels by PIP2 and its stabilization by Gbetagamma

Inward rectifier K+ channels, which modulate electrical activity in many cell types, are regulated by protein kinases, guanine-nucleotide-binding proteins (G proteins) and probably actin cytoskeleton. Generation of phosphatidylinositol 4,5-bisphosphate (PIP2) by ATP-dependent lipid kinases is known to activate inward rectifier K+ channels in cardiac membrane patches. Here we report that several cloned inward rectifier K+ channels directly bind PIP2, and that this binding correlates with channel activity. Application of ATP or PIP2 liposomes activates the cloned channels. Stabilized by lipid phosphatase inhibitors, PIP2 antibodies potently inhibit each channel with a unique rate (GIRK1/4 approximately GIRK2 >> IRK1 approximately ROMK. Consistent with the faster dissociation of PIP2 from the GIRK channels, the carboxy terminus of GIRK1 binds 3H-PIP2 liposomes more weakly than does that of IRK1 or ROMK1. Mutation of a conserved arginine to glutamine at position 188 reduces the ability of ROMK1 to bind PIP2 and increases its sensitivity to inhibition by PIP2 antibodies. Interactions between GIRK channels and PIP2 are modulated by the betagamma subunits of the G protein (Gbetagamma). When GIRK1/4 channels are allowed to run down completely, they are not activated by addition of Gbetagamma alone, but application of PIP2 activates them in minutes without Gbetagamma and in just seconds with Gbetagamma. Finally, coexpression of Gbetagamma with GIRK channels slows the inhibition of K+ currents by PIP2 antibodies by more than 10-fold. Thus Gbetagamma activates GIRK channels by stabilizing interactions between PIP2 and the K+ channel.

Biochemical characterisation of an epitope on the surface membrane antigen (Cs-gp200) of the pathogenic piscine haemoflagellate Cryptobia salmositica Katz 1951

A protective surface antigen (200 kDa) on C. salmositica was detected using a monoclonal antibody (mAb-001). Enzymatic studies on the epitope indicated that it was sensitive to nonspecific protease K and to site-specific trypsin and protease V8 but not to alpha-chymotrypsin. The reactivity of the epitope with mAb-001 was not affected when the antigen was denatured with 8 M urea; however, reduction of the antigen with dithiothreitol destroyed the epitope. The epitope was susceptible to sodium m-periodate oxidation and N-glycosidase F, but not to O-glycosidase or neuraminidase. It was also sensitive to mild potassium hydrochloride hydrolysis and to phospholipase C, which is specific for phosphatidylinositol. These results suggest that the epitope consists of a polypeptide, a carbohydrate, and probably a phospholipid. The asparagine-bound N-glycosidically linked hybrid-type carbohydrate chain has the minimum length of a chitobiose core unit. There is probably a phosphatidylinositol residue which anchors the polypeptide to the surface membrane. The antigen is extensively posttranslationally modified.

Fibroblast growth factor receptor 2 limits and receptor 1 accelerates tumorigenicity of prostate epithelial cells

Progressive loss of the differentiated phenotype and communication with stroma accompanies the transition of nonmalignant rat prostate epithelial cells to anaplastic, malignant tumors. Here we show that cell surface expression of the fibroblast growth factor receptor 2 (FGFR2) tyrosine kinase is reduced in malignant tumor cell populations (type II) and undetectable at the mRNA level in 30% of cells. This is in addition to the irreversible loss by splice switching of the FGFR2 ectodomain that abrogates response to FGF-7 and homologues from the stroma. One hundred % of type II malignant cells express FGFR1, which is normally expressed in the stroma. Expression of the FGFR1 kinase in premalignant type I tumor epithelial cells by transfection accelerated progression to the malignant phenotype. In contrast to the FGFR2 kinase fused to the ectodomain of FGFR1, the FGFR1 kinase failed initially to support a mitogenic response to FGF-2 in type I tumor cells. However, the FGFR1-transfected cells acquired a mitogenic response after extensive proliferation of the cell population. Resident FGFR2 and ectopic FGFR1 appeared to be partitioned in the type I cells, because neither full-length nor truncated isoforms of FGFR1 affected the mitogenic response of the other. Restoration of the FGFR2IIIb kinase to malignant cells expressing FGFR1 depressed tumor growth rates, restored responsiveness to stromal cells, and restored epithelial cell differentiation. These observations reveal that homologous FGFR1 and FGFR2 kinases play very different roles in cell growth and differentiation and in development and support of the malignant phenotype.

Laparoscopic cecal ligation and puncture in the rat. Surgical technique and preliminary results

BACKGROUND

We describe a technique of laparoscopic cecal ligation and puncture (CLP) in the rat analogous to open CLP which may facilitate the study of minimally invasive surgery (MIS) and peritonitis.

METHODS

Forty-four rats were randomized to either laparoscopic or open CLP and their 3-day mortality was recorded. Autopsies were performed for peritoneal fluid cultures, measurement of the length of ligated cecum, and scoring of the degree of cecal necrosis.

RESULTS

Laparoscopic CLP required slightly longer operating times compared to open CLP (average 15.6 vs 13.1 min, p = 0.002). Three-day postoperative mortality was 36.4% and 22.7% for open and laparoscopic CLP, respectively (p = NS). There were no differences in the length of ligated cecum or the cecal necrosis score between the open and laparoscopic CLP groups.

CONCLUSION

Laparoscopic CLP is feasible and produces a fecal peritonitis with similar characteristics to those of traditional open CLP.

Borrelia burgdorferi strain-specific Osp C-mediated immunity in mice

Antibodies to the outer surface proteins (Osps) A, B, and C of the spirochete Borrelia burgdorferi can prevent infection in animal models of Lyme borreliosis. We have previously demonstrated that immune serum from mice infected with B. burgdorferi N40 can also prevent challenge infection and induce disease regression in infected mice. The antigens targeted by protective and disease-modulating antibodies are presently unknown, but they do not include Osp A or Osp B. Because Osp C antibodies are present in immune mouse serum, we investigated the ability of hyperimmune serum to recombinant Osp C (N40) to protect mice against challenge infection with N40 spirochetes. In both active and passive immunization studies, Osp C (N40) antiserum failed to protect mice from challenge infection with cultured organisms. Mice actively immunized with recombinant Osp C (N40) were susceptible to tick-borne challenge infection, and nymphal ticks remained infected after feeding on Osp C-hyperimmunized mice. In contrast, similar immunization studies performed with Osp C (PKo) antiserum prevented challenge infection of mice with a clone of PKo spirochetes pathogenic for mice. Both Osp C (N40) and Osp C (PKo) antisera showed minimal in vitro borreliacidal activity, and immunofluorescence studies localized Osp C beneath the outer membrane of both N40 and PKo spirochetes. We conclude that Osp C antibody-mediated immunity is strain specific and propose that differences in Osp C surface expression by spirochetes in vivo may account for strain-specific immunity.