Low-dose acyclovir prophylaxis for the prevention of herpes simplex virus disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Currently, acyclovir (ACV) at 1000 mg/day is widely used as prophylaxis in the early phase of hematopoietic stem cell transplant (HSCT) in Japan. However, low-dose ACV (200 mg/day) has been shown to prevent varicella zoster virus reactivation in the middle and late phases of HSCT.

METHODS

Therefore, in this study, we decreased the dose of ACV to 200 mg/day in the early phase after HSCT. We analyzed 93 consecutive herpes simplex virus (HSV)-seropositive patients who underwent allogeneic HSCT for the first time in our center between June 2007 and December 2011.

RESULTS

Before August 2009, 38 patients received oral ACV at 1000 mg/day (ACV1000) until day 35 after HSCT, whereas 55 patients received oral ACV at 200 mg/day (ACV200) after September 2009. We compared the cumulative incidence of HSV infection in the 2 groups. Oral ACV was changed to intravenous administration because of intolerance in 66% and 45% of the patients in the ACV1000 and ACV200 groups, respectively (P = 0.060). The probability of severe stomatitis (Bearman grade II-III) was 76% and 60% in the ACV1000 and ACV200 groups, respectively (P = 0.12). The number of patients who developed HSV disease before day 100 after HSCT was 0 in the ACV1000 group and 2 in the ACV200 group, with a cumulative incidence of 3.6% (P = 0.43). HSV disease in the latter 2 patients was limited to the lips and tongue and was successfully treated with ACV or valacyclovir at a treatment dose.

CONCLUSION

ACV at 200 mg/day appeared to be effective for preventing HSV disease in the early phase after HSCT.

Influence of HLA-DRB1 alleles on the susceptibility and resistance to multiple sclerosis in Japanese patients with respect to anti-aquaporin 4 antibody status

Background: Epistatic interactions between human leukocyte antigen (HLA)-DRB1 alleles alter multiple sclerosis (MS) risk in Caucasians. Such interactions have never been studied in Asian MS patients.

Objective: To investigate the influence of HLA-DRB1 alleles, including epistatic interactions at this locus, in Japanese MS patients with and without the anti-aquaporin 4 (AQP4) antibody.

Methods: The HLA-DRB1 locus was genotyped in 108 MS patients and 127 healthy controls. MS patients were further classified into two groups according to anti-AQP4 antibody status (27 positive and 81 negative).

Results: HLA-DRB1*09 (adjusted odds ratio (OR) = 0.243, 95% confidence interval (CI) 0.099—0.533) and HLA-DRB1*01 (adjusted OR = 0.327, 95% CI 0.103—0.873) decreased the incidence of anti-AQP4 antibody-negative MS. By contrast, HLA-DRB1*12 increased the risk of anti-AQP4 antibody-positive MS (adjusted OR = 3.691, 95% CI 1.233—10.565). Individuals with HLA-DRB1*09/15 decreased the risk of anti-AQP4 antibody-negative MS (adjusted OR = 0.164, 95% CI 0.026—0.593), while those with HLA-DRB1*12/15 increased the risk of anti-AQP4 antibody-positive MS (adjusted OR = 10.870, 95% CI 2.004—81.752).

Conclusions: The ability of HLA-DRB1*09 to reduce the risk of anti-AQP4 antibody-negative MS may arise from an interaction with HLA-DRB1*15. By contrast, HLA-DRB1*12 increases susceptibility to anti-AQP4 antibody-positive MS, possibly via an interaction with HLA-DRB1*15.

Depression among caregivers of the frail elderly in Japan before and after the introduction of the Public Long-Term Care Insurance System

Cross sectional studies were conducted in five towns in Japan before and after the introduction of the Long-term Care Insurance System (LTCIS), in order to evaluate the factors relating to depression among family caregivers for the frail elderly. Depressive caregivers were more likely to consult with their doctors, to be in poor health, to care for demented elderly with behavioral disturbances than the non-depressive caregivers both before and after the LTCIS. Before LTCIS, depressive caregivers were more likely to attend to the elderly for more than 16 hours per day than their counterparts. After the LTCIS, depressive caregivers were more likely to be a spouse, to care for a frail elderly male, and less likely to be able to go out without accompanying the elderly than their counterparts. Even after the introduction of LTCIS, half of the caregivers were depressive. It is suggested that a government agency should be created to support not only the frail elderly but also their caregivers.

Small number of HTLV-1-positive cells frequently remains during complete remission after allogeneic hematopoietic stem cell transplantation that are heterogeneous in origin among cases with adult T-cell leukemia/lymphoma

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can provide long-term remission for patients with adult T-cell leukemia/lymphoma (ATLL) caused by human retrovirus, human T-lymphocyte virus (HTLV-1). To understand how HTLV-1-positive cells including ATLL cells were suppressed by allo-HSCT, we examined HTLV-1 provirus load and residual ATLL cells in peripheral blood of transplant recipients using PCR-based tests. We found that the copy number of HTLV-1 genome, called provirus, became very small in number after allo-HSCT; however, in most cases, provirus did not disappear even among long-term survivors. Tumor-specific PCR tests demonstrated that most of HTLV-1-positive cells that remained long after transplantation were not primary ATLL cells but donor-derived HTLV-1-positive cells. We also found a case having very low amount of residual disease in peripheral blood even long after transplantation. There was only one recipient in whom we failed to show the presence of HTLV-1 genome and antibody against HTLV-1 even with an extensive search, which strongly suggested the elimination of HTLV-1 after allo-HSCT. These results demonstrated that after allo-HSCT the small amount of residual HTLV-1-positive cells were heterogeneous in origin and that long-term disease control for ATLL could be obtained without the complete elimination of HTLV-1.

Somatic cytogenetic and azoospermia factor gene microdeletion studies in infertile men

The objective of the present study was to determine the frequency of somatic chromosomal anomalies and Y chromosomal microdeletions (azoospermia factor genes, AZF) in infertile males who seek assisted reproduction. These studies are very important because the assisted reproduction techniques (mainly intracytoplasmic sperm injection) bypass the natural selection process and some classical chromosomal abnormalities, microdeletions of AZF genes or some deleterious genic mutations could pass through generations. These genetic abnormalities can cause in the offspring of these patients male infertility, ambiguous external genitalia, mental retardation, and other birth defects. We studied 165 infertile men whose infertility was attributable to testicular problems (60 were azoospermic, 100 were oligospermic and 5 were asthenospermic). We studied 100 metaphases per patient with GTG banding obtained from temporary lymphocyte culture for chromosomal abnormality detection and performed a genomic DNA analysis using 28 Y chromosome-specific sequence-tagged sites for Y AZF microdeletion detection. Karyotyping revealed somatic anomalies in 16 subjects (16/165 = 9.6%). Of these 16, 12 were in the azoospermic group (12/60 = 20%) and 4 were in the oligospermic group (4/100 = 4%). The most common chromosomal anomaly was Klinefelter syndrome (10/165 = 6%). Microdeletions of AZF genes were detected in 12 subjects (12/160 = 7.5%). The frequencies detected are similar to those described previously. These results show the importance of genetic evaluation of infertile males prior to assisted reproduction. Such evaluation can lead to genetic counseling and, consequently, to primary and secondary prevention of mental retardation and birth defects.

Life-threatening bleeding and acquired factor V deficiency associated with primary systemic amyloidosis

Acquired factor X deficiency has been described in patients with amyloidosis but acquired factor V deficiency is quite rare. We report here a case of life-threatening bleeding and acquired factor V deficiency associated with primary amyloidosis. A 50-year-old man who had no previous hemorrhagic diathesis was referred to our hospital because of recurrent epistaxis, gingival bleeding and hemospermia. The laboratory examination revealed that both the prothrombin time (PT) and the activated partial thromboplastin time (aPTT) were significantly prolonged, and factor V activities were markedly decreased to 14-39% of the normal value. Other coagulation factors such as fibrinogen, prothrombin, factor VII, factor VIII, factor IX and factor X were subnormal and normal. Transaminases were slightly elevated but serological tests of hepatitis B and hepatitis C were negative. Mild hepatosplenomegaly was noted without sign of liver cirrhosis. The PT and aPTT obtained 8 years ago when he received a cholecystectomy due to cholecystitis were both normal. Specific assays for the detection of factor V inhibitor were repeatedly performed but no factor V inhibitor was found. Furthermore, a significant recovery of the infused factor V was noted shortly after an intravenous administration of 5-10 U fresh frozen plasma, but it did not last more than 6 h. Melena, bleedings into the left shoulder and buttock, and finally mortal retroperitoneal hemorrhage developed despite repeated infusions of large amounts of fresh frozen plasma. Acquired factor V deficiency associated with primary amyloidosis was suspected but histological diagnosis was not obtained because of the severe bleeding tendency. Autopsy revealed hepatosplenomegaly and massive deposits of AL amyloid in the liver, spleen, heart and other parenchymal organs. Perivascular amyloid deposition and factor V deficiency are both thought to be the cause of the severe hemorrhagic tendency seen in this patient.

Protein kinase A phosphorylates titin's cardiac-specific N2B domain and reduces passive tension in rat cardiac myocytes

beta-Adrenergic stimulation of cardiac muscle activates protein kinase A (PKA), which is known to phosphorylate proteins on the thin and thick filaments of the sarcomere. Cardiac muscle sarcomeres contain a third filament system composed of titin, and here we demonstrate that titin is also phosphorylated by the beta-adrenergic pathway. Titin phosphorylation was observed after beta-receptor stimulation of intact cardiac myocytes and incubation of skinned cardiac myocytes with PKA. Mechanical experiments with isolated myocytes revealed that PKA significantly reduces passive tension. In vitro phosphorylation of recombinant titin fragments and immunoelectron microscopy suggest that PKA targets a subdomain of the elastic segment of titin, referred to as the N2B spring element. The N2B spring element is expressed only in cardiac titins, in which it plays an important role in determining the level of passive tension. Because titin-based passive tension is a determinant of diastolic function, these results suggest that titin phosphorylation may modulate cardiac function in vivo.

Strategies for mimicking Neisserial saccharide epitopes as vaccines

Monoclonal antibody (mAb) 2C7 recognizes a conserved and widely expressed oligosaccharide (OS) epitope on Neisseria gonorrhoeae. This OS epitope evokes a significant bactericidal and opsonic immune response after natural infection and vaccination. The OS epitope structure represents an excellent target for a potential protective gonococcal vaccine. Because carbohydrate antigens are T-cell independent, inducing weak antibody responses, OS molecules are not useful immunogens. We developed and examined two different strategies to mimic the 2C7 OS epitope: (i) an anti-idiotope (mAb CA1); and (ii) a peptide (PEP-1). These surrogate immunogens elicited antibody responses in mice (CA1 and PEP-1) and rabbits (CA1) that were bactericidal in vitro against gonococci. Both CA1 and PEP-1 are true immunologic mimics of OS and may form a basis for the development of vaccine candidates for human immunization against N. gonorrhoeae.

Selection of peptides that bind to the core oligosaccharide of R-form LPS from a phage-displayed heptapeptide library

To characterize common sites within the core oligosaccharide of the R-form lipopolysaccharide (LPS), we screened peptides from a phage-displayed heptapeptide library by using the most truncated form of R-LPS, Re-LPS (S. Typhimurium SL1165) as a ligand. After three rounds of biopanning/amplification and subsequent screening by phagemid enzyme-linked immunosorbent assay (ELISA), we selected three distinct clones that bind to the ligand LPS. We characterized the binding sites of the three clones by ELISA and thin-layer chromatography immunostaining and found that the three clones bind the two Re-LPSs (SL1165 and S. Minnesota Re595) and Rb2-LPS. In addition, one of the clones also bound to S-form LPS (S. Enteritidis). Current data show that those clones bind to common carbohydrate structure(s) expressed in the core oligosaccharides of those LPS samples.

Titin-actin interaction in mouse myocardium: passive tension modulation and its regulation by calcium/S100A1

Passive tension in striated muscles derives primarily from the extension of the giant protein titin. However, several studies have suggested that, in cardiac muscle, interactions between titin and actin might also contribute to passive tension. We expressed recombinant fragments representing the subdomains of the extensible region of cardiac N2B titin (tandem-Ig segments, the N2B splice element, and the PEVK domain), and assayed them for binding to F-actin. The PEVK fragment bound F-actin, but no binding was detected for the other fragments. Comparison with a skeletal muscle PEVK fragment revealed that only the cardiac PEVK binds actin at physiological ionic strengths. The significance of PEVK-actin interaction was investigated using in vitro motility and single-myocyte mechanics. As F-actin slid relative to titin in the motility assay, a dynamic interaction between the PEVK domain and F-actin retarded filament sliding. Myocyte results suggest that a similar interaction makes a significant contribution to the passive tension. We also investigated the effect of calcium on PEVK-actin interaction. Although calcium alone had no effect, S100A1, a soluble calcium-binding protein found at high concentrations in the myocardium, inhibited PEVK-actin interaction in a calcium-dependent manner. Gel overlay analysis revealed that S100A1 bound the PEVK region in vitro in a calcium-dependent manner, and S100A1 binding was observed at several sites along titin's extensible region in situ, including the PEVK domain. In vitro motility results indicate that S100A1-PEVK interaction reduces the force that arises as F-actin slides relative to the PEVK domain, and we speculate that S100A1 may provide a mechanism to free the thin filament from titin and reduce titin-based tension before active contraction.

Successful treatment with a chimeric anti-CD20 monoclonal antibody (IDEC-C2B8, rituximab) for a patient with relapsed mantle cell lymphoma who developed a human anti-chimeric antibody

Mantle cell lymphoma (MCL) has a poor prognosis without cure; the median overall survival ranges only from 3 to 4 years irrespective of conventional therapeutic regimens. IDEC-C2B8 (rituximab), a chimeric monoclonal antibody against the B-cell-specific antigen CD20, induces an evaluable clinical response in patients with MCL with mild toxicities. However, the single agent rituximab cannot cure MCL. Due to its low immunogenicity, an antibody against IDEC-C2B8 (human antichimeric antibody [HACA]) has rarely been produced in vivo. We report a patient with relapsed MCL who was successfully treated with IDEC-C2B8 for over a year although she developed HACA 6 months after the initial administration of IDEC-C2B8 in the phase II clinical trial conducted by Zenyaku Kogyo Co. Ltd. We followed the pharmacokinetics of IDEC-C2B8, the serum HACA titer, and the number of B lymphocytes in the peripheral blood in relation to clinical response. The HACA became undetectable soon after subsequent administrations of IDEC-C2B8. When the serum level of IDEC-C2B8 was kept elevated, clinical responses were apparently observed and HACA disappeared during this response period. There were no significant clinical toxicities related to the appearance of HACA. The present findings suggested that IDEC-C2B8 is effective and safe even in patients who have developed HACA.

Alpha-glucosidase inhibitors with a 4,5,6,7-tetrachlorophthalimide skeleton pendanted with a cycloalkyl or dicarba-closo-dodecaborane group

Previous studies of alpha-glucosidase inhibitors derived from thalidomide revealed that 4,5,6,7-tetrachloro-N-alkylphthalimide derivatives are superior lead compounds. Structure-activity relationship studies indicated that a hydrophobic group at the N(2) position is mandatory for potent activity. Accordingly, we have designed and synthesized some 4,5,6,7-tetrachloro-N-cycloalkylphthalimide and 4,5,6,7-tetrachloro-N-dicarba-closo-dodecaborane derivatives. The prepared compounds exhibited potent alpha-glucosidase-inhibitory activity. Among them, 4,5,6,7-tetrachloro-N-cycloheptylphthalimide (9) showed the most potent activity, being approximately 30 times more active than the classical inhibitor, 1-deoxynojirimycin (1).

Mechanical properties of titin isoforms

Titin is a giant filamentous polypeptide of multi-domain construction spanning between the Z- and M-lines of the sarcomere. As a result of differential splicing, length variants of titin are expressed in different skeletal and cardiac muscles. Here we first briefly review some of our previous work that has revealed that titin develops force in sarcomeres either stretched beyond their slack length (passive force) or shortened to below the slack length (restoring force) and that titin's force underlies a large fraction of the diastolic force of cardiac muscle. Next we present our mechanical and immunoelectron microscopical (IEM) studies of skeletal and cardiac muscles that express titin isoforms. The previously deduced molecular properties of titin were used to model titin's extensible region in the sarcomere as serially linked WLCs: rigid segments (containing folded Ig/Fn domains) and more flexible segments (PEVK segment). The model was tested on skeletal muscle fibers that express titin isoforms with tandem Ig and PEVK length variants. The model adequately predicts titin's behavior along a wide sarcomere length range in skeletal muscle, but at long sarcome lengths (SLs), predicted forces are much higher than those determined experimentally. IEM reveals that this may result from Ig domain unfolding. Experiments were also performed on cardiac myocytes from mouse and cow that express predominantly a small cardiac titin isoform (N2B titin) or a large isoform (N2BA titin), respectively. The passive tension-SL relation of myocytes was found to increase more steeply with SL in mouse than in cow. IEM revealed an additional source of extensibility within both of these cardiac titins: the unique N2B sequence (absent in skeletal muscle). Furthermore, the PEVK segment of the N2BA isoform extended to a maximal length of approximately 200 nm, as opposed to approximately 60 nm for the N2B isoform. We propose that, along the physiological SL range, the long PEVK segment found in N2BA titins results in a low PEVK fractional extension and that this underlies the lower passive tensions of N2BA-expressing cow myocytes.

[Gastric mucosal immunity induced by H. pylori infection]

H. pylori infection induces various humoral and cellular immunities in gastric mucosa. Some reports indicate predominant CD4+ cells infiltrate in H. pylori infected gastric mucosa, and these cells express the T helper 1 phenotype. Local humoral immunity is also induced. Gastric plasma cells produce anti-H. pylori antibodies, however, their protective immunity is not enough to eradicate bacteria in human. We found heat shock protein 60 kDa (hsp60) may be closely associated with pathogenesis in MALT lymphoma. IgG1 antibodies to hsp60 were significantly correlated with the antibodies to H. pylori whole cell in patients with MALT lymphoma. CD40-CD40L dependent B cell proliferation was induced by cytokine and/or hsp60 stimulations in those patients. Cytotoxicity of gastric epithelial cells which is associated with host immunity induced by H. pylori infection is still unclear. We found that lymphocytes from patients with peptic ulcer showed cytotoxicity to gastric cell line HGC-27 in vitro. Cytotoxicity was enhanced by cytokine stimulus to T-lymphocytes and by heat stress and/or patients' antibodies treatment of HGC-27 cells. The pathogenicity of H. pylori may involve not only bacterial virulence factor but also host immunity. Studies of mucosal local immunity will help explain the mechanisms of H. pylori induced gastrodoudenal diseases.

Generation, Microwave Spectrum, Barrier to Internal Rotation of Methyl Group, and ab Initio MO Calculation of syn-2-Nitrosopropene, syn-CH(2)&dbond;C(CH(3))&bond;N&dbond;O

syn-2-Nitrosopropene was generated, in the gas phase, by chemical reaction of 1-chloro-2-(hydroxyimino)propane with K(2)CO(3) and identified by microwave spectroscopy. The microwave spectrum of the reaction product was observed in the frequency range from 8.0 to 40.0 GHz. The rotational constants (MHz) were determined as A = 8744.09(6), B = 4846.07(2), and C = 3177.84(3) for CH(2)&dbond;C(CH(3))&bond;(14)NO (normal species) and A = 8664.36(5), B = 4822.15(3), and C = 3157.04(3) for CH(2)&dbond;C(CH(3))&bond;(15)NO ((15)N species) in the ground vibrational state. The values of the planar moment (P(cc) = (I(a) + I(b) - I(c))/2) obtained for the normal and (15)N species were 1.525(1) and 1.526(1) u Å(2), respectively. This suggests that the nitrogen atom lies in or is close to the ab inertial plane of the molecule and shows also that only two hydrogen atoms are located symmetrically out of the symmetry plane. The reaction product was determined to be syn-2-nitrosopropene by comparing the observed and calculated rotational constants, kappa (Ray's asymmetry parameter) and r(s) coordinates of the nitrogen atom. The dipole moments (D) were determined to be µ(a) = 2.43(5), µ(b) = 1.12(7), and µ(total) = 2.67(7). The barrier heights of the internal rotation owing to the methyl group of the normal species in the ground and first excited torsional states were determined to be 1750(50) and 1740(50) cal/mol (1 cal/mol = 4.184 J/mol), respectively. The (14)N nuclear quadrupole coupling constants (MHz) were determined to be chi(aa) = 0.25(21), chi(bb) = -7.11(40), and chi(cc) = 6.85(61). Two vibrational excited states were observed and the vibrational frequencies (cm(-1)) of the C-N and C-C torsional modes were determined to be 160(40) and 175(40), respectively. The lifetime of syn-2-nitrosopropene was found to be ca. 2 min in the waveguide cell. Copyright 2000 Academic Press.

Alpha-glucosidase inhibitors with a phthalimide skeleton: structure-activity relationship study

Alpha-glucosidase inhibitors with a phthalimide skeleton were prepared. Structure-activity relationship studies indicated a critical role for the hydrophobicity of the substituent at the nitrogen atom of the phthalimide skeleton. Introduction of electron-withdrawing groups, including a nitro group and chlorine, influenced the activity. Optimization studies led us to design 4,5,6,7-tetrachloro-N-phenylphthalimide (CPOP) and its N-phenylalkyl derivatives. CP0P and 4,5,6,7-tetrachloro-N-(4-phenylbutyl)phthalimide (CP4P) proved to be more potent alpha-glucosidase inhibitors than the known inhibitor 1-deoxynojirimycin.

Novel alpha-glucosidase inhibitors with a tetrachlorophthalimide skeleton

Novel alpha-glucosidase inhibitors with a tetrachlorophthalimide skeleton were prepared and their structure-activity relationships were analyzed. Among them, N-phenyl-4,5,6,7-tetrachlorophthalimide (CPOP: 2) and N-(4-phenylbutyl)-4,5,6,7-tetrachlorophthalimide (CP4P: 6) showed very potent inhibitory activity, being more potent than 1-deoxynojirimycin (dNM: 1). Mechanistic studies revealed that CPOP (2) and CP4P (6) inhibit alpha-glucosidase non-competitively and competitively, respectively.

Separation of lipooligosaccharides by linear gradient gel electrophoresis

Lipooligosaccharides (LOSs) are one of the major antigenic and immunogenic components on the outer membrane of mucosal Gram-negative bacteria. These glycolipid antigens are in the M(r) range of 3-7 kDa, and SDS/PAGE has been used as an analytical tool. Although we are able to separate relatively higher M(r) LOS components by mini-PAGE, we encounter difficulties in resolving LOS components below 3.6 kDa present in heterogeneous LOS preparations. In the present study, we selected PID2 LOS consisting of six LOS components of 3.0-5.1 kDa as a model LOS and examined mini-PAGE conditions not only to resolve smaller M(r) LOS components but also to retain resolving capability of higher LOS components. We found that mini-PAGE with stepwise and linear gradient gels (glycine-SDS) resolved smaller M(r) LOS components. Mini-PAGE with linear gradient gels gave the best resolution, and LOS components of 3.0-5.1 kDa were separated as tight and even bands. Because of the resolution, LOS components were stained chemically and immunochemically much better than those on continuous or stepwise gradient gels. Our study also showed that preformed tricine-SDS (TSDS) minigels such as 16.5 and 10-20% (linear gradient) did not resolve PID2 LOS, which indicated that heterogeneous LOS preparations may not be fully analyzed by using these TSDS minigels. By using glycine-SDS linear gradient mini-PAGE, we should be able not only to screen expression of LOSs but also to characterize smaller M(r) LOS components present in heterogeneous LOS preparations whose identities may have been neglected in the past.

Structural and immunochemical characterization of a Neisseria gonorrhoeae epitope defined by a monoclonal antibody 2C7; the antibody recognizes a conserved epitope on specific lipo-oligosaccharides in spite of the presence of human carbohydrate epitopes

Lipo-oligosaccharides (LOS) produced by Neisseria gonorrhoeae are important antigenic and immunogenic components of the outer membrane complex. Previously, we showed that murine monoclonal antibody (mAb) 2C7 did not cross-react with human glycosphingolipids but identified the LOS epitope that is widely expressed in vivo and in vitro (Gulati, S., McQuillen, D. P., Mandrell, R. E., Jani, D. B., and Rice, P. A. (1996) J. Infect. Dis. 174, 1223-1237). In the present study, we analyzed the structure of gonococcal strain WG LOS containing the 2C7 epitope and investigated the structural requirements for expression of the epitope. We determined that the WG LOS components are Hep[1]-elongated forms of 15253 LOS that have a lactose on both Hep[1] and Hep[2] (Yamasaki, R., Kerwood, D. E., Schneider, H., Quinn, K. P., Griffiss, J. M., and Mandrell, R. E. (1994) J. Biol. Chem. 269, 30345-30351). In addition, we found that expression of the 2C7 epitope within the LOS is blocked when the Hep[2]-lactose is elongated. Based on the structural data of these LOS and the results obtained from immunochemical analyses, we conclude the following: 1) mAb 2C7 requires both the 15253 OS minimum structure and the N-linked fatty acids in the lipoidal moiety for expression of the epitope; 2) mAb 2C7 binds to the LOS that elongates the lactose on Hep[1] of the 15253 OS, but not the one on Hep[2]; and 3) the 2C7 epitope is expressed on gonococcal LOS despite the presence of human carbohydrate epitopes such as a lactosamine or its N-acetylgalactosaminylated (globo) form. Our study shows that the conserved epitope defined by mAb 2C7 could potentially be used as a safe site for the development of a vaccine candidate.

Single molecular observation of the interaction of GroEL with substrate proteins

To understand the mechanism of GroEL-assisted protein folding, we observed the interaction of fluorescence-labeled GroEL with fluorescence-labeled substrate proteins at the single molecule level by total internal reflection fluorescence microscopy. GroEL with a A133C mutation in the equatorial domain was labeled with a fluorescent dye, tetramethylrhodamine. As substrate proteins, we used the largely denatured and partly denatured forms of bovine beta-lactoglobulin, both labeled with another fluorescent dye, Cy5. The complexes formed by GroEL with these substrates were characterized by size-exclusion gel chromatography. The recovered complexes were then observed by fluorescence microscopy. For both substrates, agreement of the fluorescent spots for tetramethylrhodamine and Cy5 indicated formation of the complex at the single molecule level. Similar observation of macroscopic binding by size-exclusion chromatography and microscopic binding by the fluorescence microscopy was done for the folding intermediate of Cy5-labeled bovine rhodanese. The fluorescence microscopy opens a new avenue for studying the interaction of GroEL with substrate proteins.

Novel small molecule nonpeptide aminopeptidase n inhibitors with a cyclic imide skeleton

A novel series of small molecule nonpeptide aminopeptidase N (APN) inhibitors with a N-phenylphthalimide or N-phenylhomophthalimide skeleton were prepared. Evaluation of their protease inhibitory activities revealed that (i) some N-phenylphthalimide analogs are potent APN inhibitors, but they are also inhibitors of another protease, dipeptidylpeptidase IV (DPP-IV), and (ii) some N-phenylhomophthalimide analogs, including 2-(2,6-diethylphenyl)-1,2,3,4-tetrahydroisoquinoline-1,3-dione (PIQ-22), are potent and specific inhibitors of APN without DPP-IV-inhibitory activity. The structure-activity relationship studies of N-phenylphthalimides and N-phenylhomophthalimides are reviewed. PIQ-22 showed potent tumor-cell invasion-inhibitory activity.

[Usefulness of endovascular grafting for abdominal aortic aneurysm]

The purpose of this study was to determine the usefulness of endovascular grafting for abdominal aortic aneurysm (AAA) compared to conventional open repair. During the period from May 1998 through to April 1999, 16 patients (control group) with AAA underwent conventional open surgery and 6 patients (stent group) underwent endovascular grafting. Surgical data including operative time and intraoperative blood loss did not differ between the two groups. However, the postoperative parameters including the initiation of oral intake, the onset of flatus and the permission to walk were significantly sooner in the stent group than the control group. The postoperative changes of coagulopathy-fibrinolytic factor were comparable between the two groups. We conclude that the endovascular grafting is minimally invasive compared to conventional open surgery. In addition, there was no consumption coagulopathy in the endovascular grafting. However, it was necessary to develop new approach with new devices in order to perform endovascular grafting more safely.

Immunoreactive growth hormone-releasing hormone (IR-GHRH) in the feto-placental circulation and differential effects of L-dopa, L-arginine and somatostatin-14 on the plasma levels of IR-GHRH in normal adults

The relation of the physiological releases of growth hormone-releasing hormone (GHRH) and growth hormone (GH) into the circulation in various conditions was investigated using a sensitive and specific radioimmunoassay for plasma GHRH. The mean fasting plasma level of immunoreactive (IR)-GHRH in 72 normal adults was 10.3 +/- 0.5 (mean +/- SEM) pg/ml and there was no significant sex difference in the level. The concentrations of IR-GHRH in plasma from the umbilical artery and umbilical vein were 107.3 +/- 20.5 pg/ml and 33.6 +/- 3.8 pg/ml, respectively, and a marked arterio-venous gradient was observed in all 12 individuals examined. The plasma level of IR-GHRH in the maternal vein was significantly lower than that in the cord blood, but was similar to that in non-pregnant women. In normal adults, although there was no apparent fluctuation in the level of plasma IR-GHRH or of plasma GH during bed rest, a significant increase of plasma IR-GHRH was detected followed by, or synchronized with the surge of plasma GH after oral administration of L-dopa. In contrast, on L-arginine infusion, no proportional elevation of plasma IR-GHRH with increase in plasma GH was observed. During and after intravenous infusion of somatostatin, the circulating IR-GHRH level did not increase, but on stopping the infusion there was an immediate and marked rebound surge of GH. We conclude that 1) the elevated IR-GHRH in the cord blood plasma originates from the fetus and may have a primary role in enhancing secretion of GH which promotes growth in early human life, and 2) the participations of GHRH in the mechanisms of GH secretion seen after administrations of L-dopa, L-arginine and somatostatin are different.

The addition of fructose or sodium citrate does not improve recovery rates of cryopreserved human spermatozoa

OBJECTIVE

To evaluate the effects of the addition of sodium citrate and/or fructose to medium containing egg yolk, glycerol and TEST buffer (TES(N-tris[hydroxymethyl] methyl-2-aminoethanesulfonic acid) plus Tris (hydroxymethyl)-aminomethane) on human sperm cryopreservation.

DESIGN

Sperm cryopreservation in three cryoprotective media, followed by thawing 3 weeks or 3 months later.

SETTING

University outpatient clinic.

MATERIAL AND METHODS

Twenty-two semen samples from fertile men were evaluated before and after freezing for 3 weeks or 3 months in three different cryoprotective media consisting of a stock solution (TEST-YOLK) to which 20% sodium citrate was added plus 2% fructose (TESTC I) or to which 20% sodium citrate, but no fructose, was added (TESTC-II).I MAIN OUTCOME MEASURES: Measurements of quantitative sperm motility, progressive motility, vitality and recovery rates before and after freezing.

RESULTS

Before freezing, the addition of the different media increased sperm progressive motility but did not change quantitative motility or vitality. Sample freezing reduced all the above variables both after 3 weeks and after 3 months, with no difference between the two freezing times. Semen analysis two hours after thawing showed a significant fall in both motility and vitality when compared with samples analyzed immediately after thawing. No significant differences in recovery rates were observed between media or within the same medium when the two freezing times (3 weeks and 3 months) were compared.

CONCLUSION

The addition of sodium citrate and/or fructose to the cryoprotective medium does not improve sperm motility or vitality after freezing.

The structure of lipooligosaccharide produced by Neisseria gonorrhoeae, strain 15253, isolated from a patient with disseminated infection. Evidence for a new glycosylation pathway of the gonococcal lipooligosaccharide

We studied the structure of the lipooligosaccharide (LOS) that is produced by Neisseria gonorrhoeae, strain 15253. This strain, recovered from a patient with disseminated infection, produces predominantly a single LOS component, and its oligosaccharide (OS) structure is different from those of previously studied LOSs. Definition of this OS structure provides additional information on the LOS biosynthesis. We determined that the 15253 OS has an unusual structure: 2 lactosyl residues at its nonreducing ends shown below, [formula: see text] where KDO is 2-keto-3-deoxy-mannooctulosonic acid and Hep is heptose. Comparison of this OS structure with those determined previously indicates the presence of a new glycosylation pathway for gonococcal OS biosynthesis: elongation of a GlcNAc-linked heptose, in contrast to elongation of the other heptose by sequential addition of glycoses which results in the antigenic similarity with human glycolipids. The current study provides not only additional structural information on LOS expressed during different clinical states of infection but also evidence for the diversity of gonococcal LOS biosynthesis. This evidence may be helpful in understanding the pathogenesis involving gonococcal LOS.

Evaluation of the effects of various factors on the serum triglyceride level in young adults

The life style of young adults has been receiving attention with a view to its improvement to preventing coronary heart diseases (CHD) in later life. In this study, for determining the influence of different life styles on the serum triglyceride level, we carried out surveys and laboratory studies on the relationships of the nutritional intake, physical activity, and cigarette smoking and alcohol consumption of young adults with their serum triglyceride levels. The nutritional survey indicated a significant correlation between the serum triglyceride level and carbohydrate intake (p < 0.01). In the survey of physical activity, a significant inverse correlation was found between the energy expenditure per kg body weight and the serum triglyceride level (p < 0.05). No significant relationship was found of smoking or drinking with the serum triglyceride level. The body mass index was found to have effects on both the serum triglyceride and total cholesterol levels. Of the factors examined, carbohydrate intake and energy expenditure per kg body weight had the greatest effects on the serum triglyceride level. Considering the trend for young people to consume large quantities of carbonated drinks, in which most of carbohydrate is sucrose, we tested the affect of a high carbohydrate diet on one group of subjects and found that it caused a significant increase in the serum triglyceride level (p < 0.05). Another group for whom a mild exercise regimen was prescribed showed slight, but not significant decrease in the serum triglyceride level. These results suggest that at least optimal nutrition and physical activity including weight control during adolescence are important for preventing CHD.

Meningococcal group A lipooligosaccharides (LOS): preliminary structural studies and characterization of serotype-associated and conserved LOS epitopes

Structural studies indicate that the neisserial lipooligosaccharides (LOS) are composed of an oligosaccharide (OS) portion with a phosphorylated diheptose (Hep) core attached to the toxic lipid A moiety. A conserved meningococcal LOS epitope, defined by monoclonal antibody (MAb) D6A, is expressed on group A and many group B and C meningococci of different LOS serotypes (J. J. Kim, R. E. Mandrell, H. Zhen, M. A. Apicella, J. T. Poolman, and J. M. Griffiss, Infect. Immun. 56:2631-2638, 1988). This MAb-defined D6A epitope is immunogenic in humans (M. M. Estabrook, R. E. Mandrell, M. A. Apicella, and J. M. Griffiss, Infect. Immun. 58:2204-2213, 1990; M. M. Estabrook, C. J. Baker, and J. M. Griffiss, J. Infect. Dis. 197:966-970, 1993). In this study, we characterize this important MAb-defined LOS epitope. Serotype L10 and L11 group A meningococal LOS were chemically modified and used to investigate what portion of the LOS molecule is important for expression of the conserved (D6A) epitope and serotype-associated LOS epitopes by use of immunoblotting techniques and selected MAbs as probes. Preliminary structural characterization of the LOS was also accomplished by electrospray ionization-mass spectrometry. Our results indicate the following. (i) Antibodies that recognize the serotype-associated or conserved LOS epitopes recognize the OS portion of the LOS. (ii) The phosphorylated diheptose core region of the OS is essential for expression of the conserved D6A epitope. (iii) The lipid portion of the molecule is important for optimum expression of the LOS epitopes. (iv) The proposed compositions of the O-deacylated LOS are consistent with the presence of a phosphorylated diheptose core and are as follows: for O-deacylated L10 LOS, 3Hex (hexose), 1HexNAc (N-acetylhexosamine), 2KDO (2-keto-3-deoxy-D-manno-octulosonic acid), 2Hep (heptose), 1PEA or 2PEA (phosphoethanolamine), and O-deacylated lipid A; and for O-deacylated L11 LOS, 2Hex, 1HexNAc, 2KDO, 2Hep, 2PEA, and O-deacylated lipid A. Because the phosphorylated diheptose core region of the LOS is essential for the formation of a conserved LOS epitope (D6A) that is immunogenic in humans, care should be taken to maintain stereochemical requirements for the expression of this conserved epitope in the design of effective, nontoxic LOS vaccines.

Demonstration of biological activity of a growth hormone-releasing hormone-like substance produced by a pheochromocytoma

The biological characteristics of a growth hormone-releasing hormone (GHRH)-like substance produced by a pheochromocytoma were studied. Analysis by gel filtration chromatography combined with the use of two distinct GHRH antisera that recognize the N- and C-termini of authentic GHRH(1-44)NH2 indicated molecular heterogeneity of the immunoreactive GHRH in the tumor extract, but a component corresponding to GHRH(1-44)NH2 was the predominant form. The biological activity of this immunoreactive component was assessed in vitro by measuring its ability to induce growth hormone release from dispersed rat anterior pituitary cells. At concentrations of 0.125-2.0 nmol/l, the test materials induced a dose-related increase in growth hormone release from the cells into the incubation medium (range 992 +/- 68-1872 +/- 32 ng.1.7 x 10(5) cells-1 x 3 h-1), similar to that observed with synthetic GHRH(1-44)NH2. (control value 640 +/- 30 ng.1.7 x 10(5) cells-1 x 3 h-1). This suggests that immunoreactive GHRH in the tumor has almost the same biological activity as the synthetic product and that a combination of pheochromocytoma and acromegaly is not always fortuitous because both diseases may be caused by a single neoplasm.

Neuraminic acid is alpha 2-->3 linked in the lipooligosaccharide of Neisseria meningitidis serogroup B strain 6275

We have analyzed the sialylated lipooligosaccharide of Neisseria meningitidis 6275. Sialylated oligosaccharide released from strain 6275 lipooligosaccharide by mild hydrolysis was determined to contain N-acetylneuraminic acid linked alpha 2-->3 to terminal galactose as shown below. [formula: see text]

Inhibition of platelet binding and aggregation by streptococcal exopolysaccharide

Streptococcal exopolysaccharides are major virulence factors in the pathogenesis of endocarditis. They promote bacterial adherence to valves and subsequent vegetation formation. Since platelet binding and aggregation by streptococci are postulated mechanisms for endocardial colonization and vegetation production, the effect of exopolysaccharide on binding and aggregation was evaluated by flow cytometry and aggregometry. Streptococcus salivarius D1, a minimal exopolysaccharide producer, bound human platelets extensively (86.8% of bacteria bound by 1 min). S. Salivarius M13 and M15 and Streptococcus mitis M4 produced larger amounts of exopolysaccharide and bound platelets significantly less (52.6%, 51.2%, 52.8%, respectively). Exopolysaccharide also inhibited platelet aggregation: Strains with minimal exopolysaccharide aggregated platelets maximally, while strains with extensive exopolysaccharide failed to induce aggregation. Removal of exopolysaccharide by shearing restored aggregation by these latter strains. Thus, exopolysaccharides can inhibit the binding and aggregation of platelets by streptococci. The virulence associated with exopolysaccharide may result from the inhibition of platelet-mediated interactions that limit disease progression.

Structural analysis of lipooligosaccharide produced by Neisseria gonorrhoeae, strain MS11mk (variant A): a precursor for a gonococcal lipooligosaccharide associated with virulence

We studied the structure of the lipooligosaccharide (LOS) that is produced by a variant A of strain MS11mk. This variant produces a single LOS that is recognized by monoclonal antibody (MAb) 2-1-L8. In a recent study of the pathogenesis of Neisseria gonorrhoeae in male volunteers, variant A gave rise to other phase variants that produce higher molecular weight LOSs, and these LOS were associated with virulence. Definition of the structure of the variant A LOS is important to understand the biosynthesis of LOS and its expression in vivo. The dephosphorylated oligosaccharide (OS) structure derived from the variant A LOS was analyzed by two-dimensional NMR and methylation analysis. The OS structure was found to be a truncated form of the LOS produced by strain F62 [Yamasaki et al. (1991) Biochemistry 30, 10566-10575]; the variant A OS is a hexamer, a beta-lactosyl residue linked to a tetrasaccharide: Gal beta 1-->4Glc beta 1-->4[GlcNAc alpha 1-->2Hep alpha 1-->3]Hep alpha 1-->KDO. We determined that the variant A LOS is a precursor for the synthesis of higher MW LOS. We also studied expression of the MAb 2-1-L8-defined epitope present on the variant A LOS. Our data indicate that the MAb-defined epitope is not a linear beta-lactosyl residue but its specificity is directed toward the phosphorylated GlcNAc-Hep-Hep residue. Since this MAb binds to gonococci, at least part of the phosphorylated diheptose area is exposed on the gonococcal surface.

Differences in pathological findings and growth hormone responses in patients with growth hormone-producing pituitary adenoma

Plasma growth hormone (GH) responses to various stimuli were examined in 21 patients with GH-producing pituitary adenomas, classified into three types by the immunohistochemistry of cytokeratin and the glycoprotein hormone alpha-subunit distribution. Seven type 1 adenomas were exclusively composed of cells in which the cytokeratin formed a dot-like pattern; they were chromophobic to hematoxylin and eosin (H&E), occasionally positive for GH, and almost completely negative for the alpha-subunit. Thirteen type 2 adenomas were composed of cells with cytokeratin that had a perinuclear distribution; they were eosinophilic to H&E, and diffusely positive for both GH and the alpha-subunit. One patient had a type 3 adenoma which had a mixed pattern of intracellular cytokeratin distribution and was chromophobic and eosinophilic to H&E. Clinically, type 1 is characterized by earlier onset, larger tumor size, and more frequent aggressive extension. Paradoxical GH responses to TRH and OGTT were seen in 1 of 6 patients (16.7%) of type 1 and 8 of 9 patients (88.9%) of type 2, and 0% of type 1 and 62.5% of type 2, respectively. Type 2 cases showed higher plasma GH response to GH-releasing hormone, and a tendency to greater suppression of plasma GH by bromocriptine compared with type 1. Octreotide acetate administration revealed that the nadir/basal ratio of plasma GH levels was 42.9 +/- 6.6% in type 1 and 13.5 +/- 5.8% in type 2. These results suggest that there is a pathophysiological difference between these two distinct types of GH-producing pituitary adenomas.

Mechanism of impaired growth hormone secretion in patients with Cushing's disease

The function of the growth hormone-releasing hormone (GHRH)-growth hormone (GH) axis in Cushing's disease was studied by monitoring (a) the GH responses to GHRH loading and L-dopa loading, (b) the GHRH response to L-dopa loading, and (c) the daytime profiles of plasma GH concentration. GH release following GHRH and L-dopa was blunted in patients as compared to that in age-matched control subjects. However, GHRH release following L-dopa was similar in patients and controls. The plasma GH levels in four patients measured every 20 min by a highly sensitive immunoradiometric assay for GH showed pulsatile GH secretion at low levels during the observation period. These results indicate that GHRH release from the hypothalamus is preserved in patients with Cushing's disease, and support the hypothesis that glucocorticoid inhibits GH secretion by altering the hypothalamic somatostatin tone.

Lipooligosaccharides (LOS) of some Haemophilus species mimic human glycosphingolipids, and some LOS are sialylated

The lipooligosaccharides (LOS) of strains of Haemophilus ducreyi, Neisseria gonorrhoeae, Neisseria meningitidis, and Neisseria lactamica contain epitopes that are antigenically and structurally similar to carbohydrates present in human glycosphingolipids. LOS from strains of Haemophilus influenzae and H. influenzae biogroup aegyptius were tested for the binding of monoclonal antibodies (MAbs) that bind to human glycosphingolipids possessing Gal beta 1-4GlcNAc (MAb 3F11) and Gal alpha 1-4Gal beta 1-4Glc (MAb anti-Pk). In solid-phase radioimmunoassays, the LOS of 18 of 19 H. influenzae type b (Hib), 8 of 19 nontypeable H. influenzae, and 10 of 20 H. influenzae biogroup aegyptius strains bound MAb anti-Pk. The LOS of 13 of 19 Hib, 10 of 16 nontypeable H. influenzae, and 2 of 18 H. influenzae biogroup aegyptius strains bound MAb 3F11. Neuraminidase treatment of the strains increased the binding of MAb 3F11 by more than twofold in 47% of the H. influenzae strains, suggesting that sialic acid occluded the LOS structure recognized by MAb 3F11. The material released from neuraminidase-treated Hib LOS was confirmed to be sialic acid by high-performance anion-exchange chromatography. A recombinant plasmid containing genes involved in Hib LOS biosynthesis directed the expression (assembly) of the 3F11 epitope in Escherichia coli. These studies demonstrate that H. influenzae and H. influenzae biogroup aegyptius express at least two LOS epitopes that are similar to those present in human glycosphingolipids. Sialic acid was present on the LOS of some H. influenzae strains and prevented the binding of MAb 3F11 to its epitope. The oligosaccharide portion of sialylated LOS may also resemble sialylated oligosaccharides present in human glycosphingolipids (gangliosides).

Ability of gonococcal and meningococcal lipooligosaccharides to clot Limulus amebocyte lysate

We investigated whether the striking difference in severity of coagulopathy observed between bacterial sepsis involving Neisseria meningitidis and Neisseria gonorrhoeae species is related to species-dependent abilities to directly activate coagulation. Using lipooligosaccharide (LOS)-activated gelation of Limulus amebocyte lysate, we compared the relative abilities of outer membrane LOS of 10 N. meningitidis and 10 N. gonorrhoeae strains to initiate coagulation. A wide range of procoagulant potencies was observed for each species, and there was significant overlap of potencies between species. Relative biological activities did not correlate with the oligosaccharide components as defined by LOS molecular weight or specific antigenic epitopes. Purified lipid A of two LOS strains of different potency demonstrated relative procoagulant biological activities similar to those of their parent LOSs. When these lipid A preparations were further separated by thin-layer chromatography, the most polar component of each lipid A possessed the majority of the procoagulant activity. We concluded that the ability of neisserial LOS to initiate coagulation of Limulus lysate is a property of the lipid A portion of the molecule and is most likely determined by fine structural differences in the lipid A which are independent of species.

Correlation between plasma levels of ACTH and cortisol in basal states and during the CRH test in normal subjects and patients with hypothalamo-pituitary disorders

Using a new ACTH-immunoradiometric assay (IRMA), we measured plasma ACTH levels in the basal states and during CRH test in normal subjects and the patients with hypothalamo-pituitary disorders. The basal levels of plasma ACTH in 76 normal young (25-45 yr) and 140 elderly (60-85 yr) subjects were 23.1 +/- 13.6, and 17.5 +/- 11.2 pg/ml, respectively. The plasma ACTH levels were less than detection limit (5 pg/ml) in 3 patients with isolated ACTH deficiency, and less than 10 pg/ml in 6 of 7 patients with hypopituitarism. A significant correlation was observed between the basal levels of plasma ACTH and of cortisol in two age groups, with almost the same regression line, showing no age-related decline in the plasma levels of ACTH and cortisol. In 2 normal subjects and 2 patients with Cushing's disease, synchronized secretions of ACTH and cortisol were observed between 0800h and 1800h. In normal subjects and the patients with pituitary disorders, a significant correlation was observed between the Area Under the Curve's for plasma ACTH and cortisol during the CRH test. The correlation constant was higher in normal subjects, but lower in the patients with acromegaly, non-functioning pituitary tumor, and Cushing's disease in this order, suggesting low sensitivity of the pituitary-adrenal axis in these patients. These results suggest that the ACTH-IRMA kit provide reliable data for clinical investigation, and that the secretions of ACTH and cortisol correlate each other in basal states and during the CRH test in the patients with pituitary disorders as well as in normal subjects.

Epitope expression and partial structural characterization of F62 lipooligosaccharide (LOS) of Neisseria gonorrhoeae: IgM monoclonal antibodies (3F11 and 1-1-M) recognize non-reducing termini of the LOS components

F62 LOS of Neisseria gonorrhoeae consists of two components. The higher molecular weight (MW) component is recognized by monoclonal antibody (MAb) 1-1-M and the smaller MW component by MAb 3F11. Epitope expression of the two LOS components and their partial structures were investigated by treating the F62 LOS with several glycosidases and then monitoring their antigenicity with the two mouse IgM MAbs. The 1-1-M-defined LOS component was cleaved with both beta-N-acetylhexosaminidase and endo-beta-galactosidase, and each cleavage resulted in the loss of expression of the 1-1-M-defined epitope. The N-acetylhexosamine (HexNAc) released by the hexosaminidase was found to be GalNAc, and the smaller oligosaccharide released by the endo enzyme was identified to be a dimer GalNAc beta----Gal. In contrast, the MAb 3F11-defined LOS component was not digested by the endo galactosidase, but it was cleaved with alpha and beta-galactosidase, and expression of the MAb 3F11-defined LOS epitope expression of the MAb 3F11-defined LOS was abolished by the treatment with each of two exo enzymes. MAb 3F11 bound to the 1-1-M-defined LOS component resulting from the removal of the beta-GalNAc residue, and the resulting LOS was further cleaved with beta-galactosidase, but not with alpha-galactosidase. From these results, we conclude the following: (1) MAbs 1-1-M and 3F11 both recognize the non-reducing termini of the LOS components; (2) the 1-1-M-defined LOS component has the GalNAc beta----Gal beta 1----4-Glc (or GlcNAc) structure, and the GalNAc beta----Gal residue is involved in the MAb 1-1-M-defined epitope; (3) the MAb 3F11-defined LOS component may not have a Gal beta 1----4GlcNAc beta 1----4Gal beta 1----4Glc structure within the molecule. However, it has beta-Gal residue at its non-reducing terminus, and this residue is involved in the MAb 3F11-defined epitope; (4) the two LOS components share a similar antigenic structure, and the 3F11-defined epitope structure is present in the MAb 1-1-M-defined LOS component. Expression of this epitope within the 1-1-M-defined LOS molecule is blocked by the beta-GalNAc residue; however, the beta-GalNAc residue at the non-reducing end may be not the only structural difference between the two components.

Radioimmunoassay of growth hormone-releasing hormone (GHRH) with a polyclonal antibody against synthetic GHRH(1-29)-Gly4-Cys-NH2: method and clinical studies

A radioimmunoassay (RIA) for growth hormone-releasing hormone (GHRH) using a polyclonal antibody against synthetic GHRH(1-29)-Gly4-Cys-NH2 has been developed. The antiserum (RBM105) showed full cross-reactivity with GHRH-(1-44)NH2, GHRH-(1-40)OH, GHRH-(1-37)OH and GHRH-(3-44)NH2, and probably recognized the region of Ala4 to Lys12 of GHRH. Since the sensitivity of the GHRH RIA was 1.5 pg/tube, the lowest detectable plasma level was 5 ng/l when an extract of 0.3 ml of plasma per tube was used. On gelfiltration chromatography, the GHRH immunoreactivity of normal plasma was eluted in the same position as synthetic GHRH. The plasma GHRH concentration in healthy subjects was 20.5 +/- 6.5 ng/l (mean +/- SD), and in patients with hypothalamic disorders was 17.4 +/- 2.0 ng/l. In contrast, the plasma GHRH level in hemodialysis-dependent, chronic renal failure (CRF-HD) patients (38.7 +/- 13.1 ng/l) was significantly higher than normal. The acromegalic patients were 24.3 +/- 11.9 ng/l, except for one patient with ectopic GHRH syndrome (990 ng/l): his plasma GHRH level reached 7,100 ng/l during operation, and then decreased logarithmically to 70 ng/l after 6 h. Somatostatin at concentrations of 10 and 1,000 nmol/l significantly suppressed (GHRH release) from primary culture cells of the GHRH-producing tumor from 17.3 +/- 0.92 ng/2 x 10(5) cells to 9.98 +/- 3.61 and 4.32 +/- 1.01 ng/2 x 10(5) cells, respectively after 48 h. These data indicate that this GHRH RIA is useful for determining the plasma GHRH concentration in normal and diseased states and also for in vitro studies of GHRH release.

Structural determination of oligosaccharides derived from lipooligosaccharide of Neisseria gonorrhoeae F62 by chemical, enzymatic, and two-dimensional NMR methods

F62 LOS of Neisseria gonorrhoeae consists of two major LOS components; the higher and smaller molecular weight (MW) components were recognized by MAbs 1-1-M and 3F11 respectively. Base-line separation of the two major oligosaccharide (OS) components from F62 LOS was achieved by Bio-Gel P-4 chromatography after dephosphorylation of the OS mixture. The structures of the two major OSs were studied by chemical, enzymatic, and 2D NMR methods [double quantum filtered COSY (DQF-COSY), delayed COSY (D-COSY), homonuclear Hartmann-Hahn spectroscopy (HOHAHA), pure-absorption 2D NOE NMR] as well as methylation followed by GC/MS analysis. The OS component derived from the MAb 1-1-M defined LOS component was determined to have a V3-(beta-N-acetylgalactosaminyl)neolactotetraose structure (GalNAc is beta 1----3-linked to a neolactotetraose) at one of its nonreducing termini as shown below. The above pentaose is linked to a branched diheptose-KDO core in which a GlcNAc is alpha-linked. The OS component derived from the MAb 3F11 defined LOS component did not have a GalNAc residue. The rest of its structure was identical to that of the OS-1, and a neolactotetraose is exposed at its nonreducing terminus. [formula: see text]

Endogenous sialylation of the lipooligosaccharides of Neisseria meningitidis

Monoclonal antibodies (MAb) 3F11 and 06B4 recognize epitopes that are conserved on gonococcal lipooligosaccharides (LOS), present on some meningococcal LOS, and conserved on human erythrocytes. LOS of some group B and C prototype meningococcal LOS strains (LOS serotypes L1 to L8) treated with neuraminidase showed increased expression of the 3F11 and 06B4 MAb-defined epitopes. Neuraminidase-treated LOS separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver stained showed a shift in migration from a component with a mass of approximately 4.8 kDa to a component with a mass of between 4.5 and 4.6 kDa. The same strains grown in medium with excess CMP-N-acetylneuraminic acid had LOS that shifted in migration to a slightly higher component (mass, approximately 4.8 kDa). Chemical analysis of the neuraminidase-digested products from one LOS indicated it contained approximately 1.5% sialic acid. Covalent linkage between sialic acid and the LOS was confirmed by analysis of de-O-acylated and dephosphorylated LOS by liquid secondary ion mass spectrometry. Three studies show that some meningococci contain sialic acid in their LOS, that the sialic acid is cleaved and lost in conventional acetic acid hydrolysis, and that the sialic acid alters the expression of MAb-defined epitopes.

Radioimmunoassay for activin A/EDF. Method and measurement of immunoreactive activin A/EDF levels in various biological materials

A radioimmunoassay (RIA) for the measurement of activin A, which is identical to erythroid differentiation factor (EDF), has been developed. A specific antiserum against activin A/EDF was raised in rabbits using a mixture of recombinant EDF and polyvinyl pyrrolidone. Of the compounds tested this polyclonal antibody cross-reacted only with bovine inhibin (3.2%) and human TGF-beta (4.2%). The least detectable value in this assay was 0.06 ng/tube. The within- and between-assay coefficients of variation at three different concentrations were 3.6-9.8% and 3.4-7.7%, respectively. Using this RIA, immunoreactive activin A/EDF levels in various biological fluids and tissues were examined. The dose-response curves of porcine follicular fluid and ovarian extract were parallel to the standard curve, and porcine follicular fluid contained high activin A/EDF immunoreactivity (1050 ng/ml). On gel chromatography of porcine follicular fluid, the major immunoreactivity was eluted in the same position as authentic activin A/EDF. Human placental extract and amniotic fluid had relatively high immunoreactive activin A/EDF levels (174 ng/g wet wt. and 63.9 ng/ml, respectively), but the dose-response curve of amniotic fluid was not parallel to the standard curve. Among rat tissues, the ovary showed the highest activin A/EDF immunoreactivity (163 ng/g wet wt.) much lower than that of porcine ovary (1020 ng/g wet wt.). Low immunoreactive activin A/EDF levels were detected in most parts of rat brain (8.7-14.2 ng/g wet wt.), except for the pituitary gland (70.0 ng/g wet wt.). The initial plasma half clearance time (t1/2) of exogenous activin A/EDF was 14 min in the rat and the plasma FSH concentration did not change significantly during this period. These results suggest that this RIA system has sufficient sensitivity and specificity to measure activin A/EDF concentrations in biological materials, and that the reproductive tissues are the main sources of activin A/EDF.