Coexistence of bone and vascular disturbances in patients with endogenous glucocorticoid excess

Purpose

Bone and vascular diseases are considered to share pathogenic mechanisms. Excess glucocorticoids, key regulators of cardiovascular and metabolic homeostasis, may promote both diseases simultaneously. We used endogenous Cushing's syndrome (CS) to investigate whether glucocorticoid excess underlies coexisting bone and vascular diseases.

Methods

We included 194 patients with adrenal tumors (ATs): autonomous cortisol secretion (ACS, n = 97) and non-functional AT (n = 97). ACS was further classified into overt CS (n = 17) and subclinical CS (SCS, n = 80). Arterial stiffness was defined as a brachial-ankle pulse wave velocity (baPWV) ≥ 1800 cm/s.

Results

Patients with ACS had higher coexistence rates of vertebral fracture and arterial stiffness (23 % vs. 2 %; p < 0.001) and vertebral fracture and abdominal aortic calcification (22 % vs. 1 %; p < 0.001) than those with non-functional AT. In patients with ACS, baPWV was negatively correlated with trabecular bone score (TBS, r = -0.33; p = 0.002), but not with bone mineral density, and vertebral fracture was associated with arterial stiffness in the logistic regression analysis. In the multivariate analysis of variance, the degree of cortisol excess (defined as CS, SCS, and non-functional AT) determined the correlation between TBS and baPWV (partial η² = 0.07; p < 0.001). In the analysis of covariance, patients with coexisting vertebral fracture and arterial stiffness had higher levels of serum cortisol after the 1-mg dexamethasone suppression test than those without.

Conclusion

In endogenous glucocorticoid excess, bone and vascular diseases frequently coexisted, and deteriorated bone quality, not bone loss, was related to arterial stiffness. Thus, glucocorticoid excess may perturb the bone-vascular axis.

Impact of Cortisol on Reduction in Muscle Strength and Mass: A Mendelian Randomization Study

CONTEXT

Prolonged exposure to pathological cortisol, as in Cushing's syndrome causes various age-related disorders, including sarcopenia. However, it is unclear whether mild cortisol excess, for example, accelerates sarcopenia due to aging or chronic stress.

OBJECTIVE

We used Mendelian randomization (MR) analysis to assess whether cortisol was causally associated with muscle strength and mass.

METHODS

Three single-nucleotide polymorphisms associated with plasma cortisol concentrations in the CORtisol NETwork consortium (n = 12 597) were used as instrumental variables. Summary statistics with traits of interest were obtained from relevant genome-wide association studies. For the primary analysis, we used the fixed-effects inverse-variance weighted analysis accounting for genetic correlations between variants.

RESULTS

One SD increase in cortisol was associated with SD reduction in grip strength (estimate, -0.032; 95% CI -0.044 to -0.020; P = 3e-04), whole-body lean mass (estimate, -0.032; 95% CI, -0.046 to -0.017; P = 0.004), and appendicular lean mass (estimate, -0.031; 95% CI, -0.049 to -0.012; P = 0.001). The results were supported by the weighted-median analysis, with no evidence of pleiotropy in the MR-Egger analysis. The association of cortisol with grip strength and lean mass was observed in women but not in men. The association was attenuated after adjusting for fasting glucose in the multivariable MR analysis, which was the top mediator for the association in the MR Bayesian model averaging analysis.

CONCLUSION

This MR study provides evidence for the association of cortisol with reduced muscle strength and mass, suggesting the impact of cortisol on the development of sarcopenia.

Whole Transcriptome Profiling of Adrenocortical Tumors Using Formalin-Fixed Paraffin-Embedded Samples

Whole transcriptome profiling is a promising technique in adrenal studies; however, whole transcriptome profiling of adrenal disease using formalin-fixed paraffin-embedded (FFPE) samples has to be further explored. The aim of this study was to evaluate the utility of transcriptome data from FFPE samples of adrenocortical tumors. We performed whole transcriptome profiling of FFPE and fresh frozen samples of adrenocortical carcinoma (ACC, n = 3), aldosterone-producing adenoma (APA, n = 3), and cortisol-producing adenoma (CPA, n = 3), and examined the similarity between the transcriptome data. We further examined whether the transcriptome data of FFPE samples could be used to distinguish tumor types and detect marker genes. The number of read counts was smaller in FFPE samples than in fresh frozen samples (P < 0.01), while the number of genes detected was similar (P = 0.39). The gene expression profiles of FFPE and fresh frozen samples were highly correlated (r = 0.93, P < 0.01). Tumor types could be distinguished by consensus clustering and principal component analysis using transcriptome data from FFPE samples. In the differential expression analysis between ACC and APA-CPA, known marker genes of ACC (e.g., CCNB2, TOP2A, and MAD2L1) were detected in FFPE samples of ACC. In the differential expression analysis between APA and CPA, known marker genes of APA (e.g., CYP11B2, VSNL1, and KCNJ5) were detected in the APA of FFPE samples. The results suggest that FFPE samples may be a reliable alternative to fresh frozen samples for whole transcriptome profiling of adrenocortical tumors.

Protective Role of DHEAS in Age-related Changes in Bone Mass and Fracture Risk

PURPOSE

Dehydroepiandrosterone sulfate (DHEAS) from the adrenal cortex substantially decreases with age, which may accelerate osteoporosis. However, the association of DHEAS with bone mineral density (BMD) and fracture is inconclusive. We conducted a Mendelian randomization (MR) analysis to investigate the role of DHEAS in age-related changes in BMD and fracture risk.

METHODS

Single nucleotide polymorphisms (SNPs) associated with serum DHEAS concentrations were used as instrumental variables (4 SNPs for main analysis; 4 SNPs for men and 5 SNPs for women in sex-related analysis). Summary statistics were obtained from relevant genome-wide association studies.

RESULTS

A log-transformed unit (µmol/L) increase in serum DHEAS concentrations was associated with an SD increase in estimated BMD at the heel (estimate, 0.120; 95% CI, 0.081-0.158; P = 9 × 10-10), and decreased fracture (odds ratio, 0.989; 95% CI, 0.981-0.996; P = 0.005), consistent with dual-energy X-ray absorptiometry-derived BMD at the femoral neck and lumbar spine. Their associations remained even after adjusting for height, body mass index, testosterone, estradiol, sex hormone-binding globulin, and insulin-like growth factor 1. The association of DHEAS with fracture remained after adjusting for falls, grip strength, and physical activity but was attenuated after adjusting for BMD. The MR-Bayesian model averaging analysis showed BMD was the top mediating factor for association of DHEAS with fracture. The association between DHEAS and BMD was observed in men but not in women.

CONCLUSION

DHEAS was associated with increased BMD and decreased fracture. DHEAS may play a protective role in decreasing fracture risk, mainly by increasing bone mass.

Necessity of Utilizing Physiological Glucocorticoids for Managing Familial Mediterranean Fever

BACKGROUND Familial Mediterranean fever is an auto-inflammatory disease caused by pyrin mutations. Glucocorticoids inhibit the production and secretion of inflammatory cytokines, including IL-6 and IL-1ß, from inflammatory cells and suppress the activation of nuclear factor-kappaB in the nucleus. However, the functions of physiological glucocorticoids in the disease remain unknown. CASE REPORT We report the case of a Japanese man with familial Mediterranean fever complicated by isolated adrenocorticotropic hormone deficiency. Patient non-compliance with hydrocortisone replacement therapy led to a series of pericarditis and fever episodes. Subsequently, the regular administration of colchicine alone could not prevent auto-inflammation. The clinical course of treatment suggested that the absence of physiological levels of glucocorticoids is crucial for familial Mediterranean fever attacks. Because familial Mediterranean fever is a pyrin abnormality-induced auto-inflammatory disease that subsequently activates cytokines via the nucleotide-binding domain, leucine-rich repeat/pyrin domain-containing 3 inflammasomes and the absence of glucocorticoids can exacerbate the severity of the auto-inflammatory disease. CONCLUSIONS Physiological glucocorticoid levels appear to be essential for the regulation of inflammasome activation via IL-6-negative regulation. However, pharmacological levels of glucocorticoids are not currently used for the prevention of familial Mediterranean fever attacks. Physicians should be aware of adrenal insufficiency as a possible disorder when they encounter cases of refractory familial Mediterranean fever.

Brown adipose activation and reversible beige coloration in adipose tissue with multiple accumulations of 18F-fluorodeoxyglucose in sporadic paraganglioma: A case report

In pheochromocytoma/paraganglioma, nontumorous high 18F-fluorodeoxyglucose accumulations are observed in both beige and brown adipose tissues. Recognizing this feature of 18F-fluorodeoxyglucose accumulation can help physicians make precise diagnoses and help them avoid the pitfalls of a false-positive 18F-fluorodeoxyglucose positron emission tomography result, preventing unnecessary interventions.

Exchange Interaction of 5,5‘-(m- and p-Phenylene)bis(10-phenyl-5,10-dihydrophenazine) Dications and Related Analogues

[structures: see text] 5,5'-(m-Phenylene)bis[(10-aryl-5,10-dihydrophenazine) dications, 3a2+ and 3b2+, and their p-analogues 4a2+ and 4b2+, were prepared, and their exchange interaction was investigated. The EPR spectra of these dications at 123 K in a butyronitrile matrix showed the population of a triplet state. The temperature dependence of the EPR signal intensity (absolute value(delta m(s)) = 2) showed that these dications had singlet ground states with deltaE(ST)/k(B) = -27 to -21 K for the m-isomer 3(2+) and with deltaE(ST)/k(B) = -10 to -8 K for the p-isomer 4(2+). Theoretical calculation of the exchange interaction J for these dications at the orthogonal torsion angle geometries was carried out for 3a2+ and 4a2+ and for (m- and p-phenylene)bisphenothiazine dications 1(2+) and 2(2+) using the broken-symmetry approach for the singlet states. A good correlation was observed between the calculated J and a MO-energy term in the triplet state, deltaE(TMO) = absolute value(HOMO(alpha) - (HOMO - 1)(alpha)). The calculated J values were negative in the order of 10 K for the m-dications (J/k(B) = -14.7 K for 1(2+), -11.5 K for 3a(2+)), but much smaller negative values were found for the p-isomers (J/k(B) = -0.9 K for 2(2+), -0.8 K for 4a2+). The smaller absolute value(J) values for the p-dications are qualitatively consistent with the experimental deltaE(ST) (2J) values.

Facile synthesis of 5,10-diaryl-5,10-dihydrophenazines and application to EL devices

[structures: see text] An efficient method for the synthesis of 5,10-diaryldihydrophenazine was developed using a recently developed Pd(0)-mediated cross-coupling reaction. The products 1k and 3c showed excellent properties as hole injection materials in electroluminescent (EL) devices.

Lack of B cell leakiness in BALB/cA-nu, scid double mutant mice

BALB/cA mice homozygous for both nu and scid mutations (BALB/cA-nu/nu, scid/scid) were developed by mating between BALB/cA-scid and BALB/cA-nu. These mice have greater longevity than C.B-17-scid because no thymic lymphoma occurs in them unlike in the latter. C.B-17-scid is known to show the leaky phenomenon in which a few clones of functional T and B cells develop in aged C.B-17-scid. Unexpectedly, the leaky B cells and T cells were absent or suppressed in BALB/cA-nu, scid mice when cytokine expressions were determined by RT-PCR, lymphocyte phenotypes by flow cytometry and serum immunoglobulin levels by ELISA. These results indicate that B cell leakiness may be induced by leaked T cells. BALB/cA-nu, scid mice may be useful as a recipient in allo- and xeno-transplantation experiments because of the absence of both thymic lymphomas and leakiness, in addition to lack of hair.

Retrograde transport of intact poliovirus through the axon via the fast transport system

Intramuscularly inoculated poliovirus is thought to spread to the central nervous system through neural pathways in humans, monkeys, and the transgenic (Tg) mice carrying the human poliovirus receptor (PVR) gene. To gain insight into molecular mechanisms for the retrograde axonal transport of poliovirus, resulting in the expression of neurovirulence, a poliovirus-sensitive ICR-PVRTg21 mouse line (Tg21) was used as an animal model for poliomyelitis. We detected poliovirus antigens in axons of the sciatic nerve. All of the Tg21 mice, which had been inoculated into the calves with 1 x 10(6) pfu of the Mahoney strain of type 1 poliovirus, showed symptoms of paralysis in the inoculated limbs (initial paralysis) within 48 h after the inoculation. The appearance of this initial paralysis was observed in mice whose sciatic nerves were transected at various times after virus inoculation. The results were indicators of the velocity of poliovirus transportation through the sciatic nerves under analysis. Poliovirus-related materials recovered from the sciatic nerve were mainly composed of intact 160S virion particles. The amount of 160S particle recovered was greatly reduced by coinjection with anti-PVR monoclonal antibody. These results suggest that one of the fast retrograde axonal transport systems is involved in poliovirus dissemination through the sciatic nerve and that IM-inoculated poliovirus is incorporated into the sciatic nerve as intact particles in a PVR-dependent manner, as it is in humans.

Establishment of a new murine-phenotypic angiosarcoma cell line (ISOS-1)

A cell line, designated ISOS-1, was established from a tumor formed by transplantation of a human angiosarcoma into mice with severe combined immunodeficiency (SCID). The cells showed endothelial properties, based on the uptake of Dil-Ac-LDL and binding of UEA-I/GSA-I lectins, but were negative for CD11b and Pan Cytokeratin. However, the cells lost differentiated characteristics such as expression of von Willebrand factor, contact inhibition growth and tube formation activity. These findings indicate that ISOS-1 is a poorly-differentiated endothelial cell line. At the 81st passage, all of the cells were positive for H-2Dd in various intensity, but not HLA-ABC. The metaphase chromosomes consistently showed a characteristic mouse, but not human, telocentric form. Furthermore, this cell line produced fatal tumor growth in SCID mice and also in BALB/c mice. These results suggest that ISOS-1 is a murine-phenotypic angiosarcoma cell line.

IL-2-induced IL-5 synthesis, but not proliferation, of human CD4+ T cells is suppressed by FK506

Regulation of T cell IL-5 synthesis was investigated using human Th cell clones. Immunosuppressant FK506 suppressed IL-5 synthesis of T cells activated through TCR in a dose-dependent manner. IL-5 gene transcription and protein synthesis were also induced in the same T cell clones upon stimulation with IL-2 and were suppressed by FK506 in a dose response similar to that induced by TCR stimulation. In contrast to TCR stimulation, neither activating protein-1, nuclear factor-AT (NF-AT), nor NF-kappaB binding activity was significantly up-regulated by IL-2 stimulation. Human IL-5 promoter/enhancer-luciferase gene construct transfected to T cell clones was transcribed upon either TCR or IL-2 stimulation and was clearly down-regulated by FK506, indicating that the approximately 500-bp human IL-5 gene segment located 5' upstream of the coding region contained FK506-sensitive enhancer elements. Our present findings clearly indicate that FK506-sensitive signaling molecules are involved in T cell IL-5 production induced by both TCR and IL-2 stimulation and suggest that IL-2 receptor signal leading to IL-5 gene transcription is transduced by a unique FK506-sensitive pathway other than the Ca2+-dependent signal transduction pathway, such as the calcineurin-NF-AT system.

IL-2-induced IL-5 synthesis, but not proliferation, of human CD4+ T cells is suppressed by FK506

Regulation of T cell IL-5 synthesis was investigated using human Th cell clones. Immunosuppressant FK506 suppressed IL-5 synthesis of T cells activated through TCR in a dose-dependent manner. IL-5 gene transcription and protein synthesis were also induced in the same T cell clones upon stimulation with IL-2 and were suppressed by FK506 in a dose response similar to that induced by TCR stimulation. In contrast to TCR stimulation, neither activating protein-1, nuclear factor-AT (NF-AT), nor NF-kappaB binding activity was significantly up-regulated by IL-2 stimulation. Human IL-5 promoter/enhancer-luciferase gene construct transfected to T cell clones was transcribed upon either TCR or IL-2 stimulation and was clearly down-regulated by FK506, indicating that the approximately 500-bp human IL-5 gene segment located 5' upstream of the coding region contained FK506-sensitive enhancer elements. Our present findings clearly indicate that FK506-sensitive signaling molecules are involved in T cell IL-5 production induced by both TCR and IL-2 stimulation and suggest that IL-2 receptor signal leading to IL-5 gene transcription is transduced by a unique FK506-sensitive pathway other than the Ca2+-dependent signal transduction pathway, such as the calcineurin-NF-AT system.

Efficient delivery of circulating poliovirus to the central nervous system independently of poliovirus receptor

The transgenic (Tg) mice carrying the human gene for poliovirus receptor (PVR) are susceptible to poliovirus intravenously (i.v.) inoculated as well as intracerebrally or intraspinally inoculated. Thus, i.v.-inoculated poliovirus may invade the central nervous system (CNS) through the blood-brain barrier (BBB). To know the contribution of PVR to tissue distribution and BBB permeability of i.v.-inoculated polioviruses, these dissemination processes were investigated and compared between the Tg mice and non-Tg mice. Distribution profile of i.v.-inoculated poliovirus in various tissues of the Tg mice is similar to that in non-Tg mice. The data suggest that tissue distribution of the virus occurs independently of the transgene for PVR. The amount of poliovirus delivered to the CNS suggested the existence of a specific delivery system of the virus to the CNS. Virus accumulation in the CNS of the Tg mice was measured up to 7.5 hr after the i.v. inoculation. The viruses, regardless of whether the virulent or attenuated strain, seem to accumulate at a constant rate of approximately 0.2 microliter/min/g tissue. Similar phenomena were observed when the viruses were inoculated into non-Tg mice. The rates of the virus accumulation in the CNS are more than 100 times higher than that of albumin, which is considered not to permeate through the BBB via a specific transport system, and only three times lower than that of monoclonal antibody against transferrin receptor (OX-26), which is a potential candidate as a drug delivery vehicle specific to the CNS. These data suggest that polioviruses permeate through the BBB at a fairly high rate, independently of PVR and virus strains.

Primary human immunodeficiency virus type 1 viremia and central nervous system invasion in a novel hu-PBL-immunodeficient mouse strain

We established four new mouse strains with defective T and B cells as well as defects in innate immunological reactions using an NK cell depletion antibody and showed that all mutant mouse strains efficiently received human peripheral blood leukocyte (PBL) engraftment (hu-PBL-scid mice). Higher levels of human immunodeficiency virus type 1 (HIV-1) replication were observed in these new hu-PBL-scid mice than in conventional hu-PBL-C.B-17-scid mice. In one particular strain, hu-PBL-NOD-scid mice, high levels of HIV-1 viremia (more than 10(6) 50% infectious doses per ml) were detected after infection with HIV-1. The plasma viral load was about 100 to 1,000 times higher than that observed in other hu-PBL-scid mice infected with HIV-1. Although high-level viremia did not correlate with the total amount of HIV-1 RNA in cells from infected mice, high levels of free virions were detected only in hu-PBL-NOD-scid mice. HIV-1 viremia induced systemic HIV-1 infection involving the liver, lungs, and brain. PCR in situ hybridization confirmed that HIV-1-infected cells invaded the brain tissue of the hu-PBL-NOD-scid mice. Our results suggest that the genetic background, including innate immunity, is critical in the development of primary HIV-1 viremia and subsequent central nervous system invasion with HIV-1. The hu-PBL-NOD-scid mouse represents a useful model for the study of the pathogenesis of HIV-1 in vivo, especially brain involvement, and therapy of primary HIV-1 viremia.

Endothelial cell differentiation into capillary structures by copolymer surfaces with phenylboronic acid groups

A ternary copolymer composed of m-acrylamidophenylboronic acid, N,N-dimethylaminopropylmethacrylamide and N-isopropylacrylamide was synthesized. Long-term culture of bovine aortic endothelial cells on this copolymer substrate demonstrated adhesion and proliferation of the cells. After 26 days in culture, endothelial cells spontaneously developed into capillary networks. The interactions between phenylboronic acid groups in copolymer and glycoconjugates on endothelial cell plasma membranes are proposed to regulate the induction of tissue formation, since phenylboronic acid groups are known to specifically form reversible complexes with cis-diol compounds such as glucose. This copolymer is a novel material capable of mediating specific signals analogous to extracellular matrix to promote proliferation of endothelial cells, inducing capillary structures and prompt angiogenesis.

Genotyping of mouse hepatitis virus strains by restriction endonuclease analysis of amplified nucleocapsid protein genes

Restriction endonuclease analysis of amplified nucleocapsid protein genes from mouse hepatitis virus (MHV) was used to differentiate 12 strains isolated from mouse liver or transplantable tumors from five facilities, and the restriction patterns of the isolates were compared with those of five well-defined MHV strains, A59, JHM, 2, S and Nu-67. The patterns of 10 isolates from three facilities were the same as that of Nu-67. The remaining two isolates revealed different patterns from the five reference strains. This study showed that reverse transcription and the polymerase chain reaction assay based restriction analysis are feasible for the detection and genotyping of MHV, and the Nu-67 related strain was the most prevalent type found in the clinical samples.

Induction of antibody responses that neutralize human T-cell leukemia virus type I infection in vitro and in vivo by peptide immunization

In order to define neutralization regions on the envelope antigen of human T-cell leukemia virus type I (HTLV-I), we have generated a number of new anti-envelope gp46 monoclonal antibodies from rats and mice. Epitopes recognized by new monoclonal antibodies which could neutralize HTLV-I in syncytium and transformation inhibition assays were localized to sequences in gp46 from amino acids 186 to 193, 190 to 195, 191 to 195, 191 to 196, and 194 to 199. Ovalbumin-conjugated synthetic gp46 peptides containing these neutralization epitopes, pep190-199 (a synthetic gp46 peptide containing amino acids 190 to 199) and pep180-204, but not pep185-194 or pep194-203, could give rise to HTLV-I-neutralizing antibody responses in rabbits. These immune or nonimmune rabbits were then challenged with HTLV-I by intravenous inoculation with 5 x 10(7) live HTLV-I-producing ILT-8M2 cells. By a PCR assay, it was revealed that HTLV-I provirus was detected in peripheral blood lymphocytes from nonimmune and pep288-312-immunized rabbits, whereas the provirus was not detected in peripheral blood lymphocytes from pep190-199- and pep180-204-immunized rabbits over an extended period. These results suggest that the induction of anti-gp46 neutralizing antibody responses by immunization with synthetic peptides has the potential to protect animals against HTLV-I infection in vivo.

Comparison of polymerase chain reaction and culture methods for detection of Mycoplasma pulmonis from nasal, tracheal and oral swab samples of rats

The polymerase chain reaction (PCR) and culture methods were used to detect Mycoplasma pulmonis in nasal, tracheal and oral swab samples of rats derived from 5 mycoplasma-contaminated and 2 mycoplasma-free facilities, and the results of both methods were compared. Thirty-four/54 and 30/54 in nasal samples, 31/54 and 28/54 in tracheal samples, and 12/39 and 30/39 in oral samples were positive in PCR and cultures, respectively. Agreements in the results of both tests were 48/54 (88.9%) in nasal samples and 49/54 (90.7%) in tracheal samples. This indicates that nasal and tracheal samples are useful for detecting M. pulmonis by PCR. The detection number for M. pulmonis from the oral cavity by PCR was remarkably lower than those of nasal and tracheal sites. These results show that the PCR method has significant potential as a rapid and sensitive method for detecting M. pulmonis in clinical samples collected from the nasal cavity and trachea.

Purification and characterisation of haemagglutinin from Bordetella bronchiseptica

A surface protein of Bordetella bronchiseptica was purified in one step by affinity chromatography with bovine submaxillary mucin coupled to agarose. The purified protein, with a mol. wt of 200 kDa and an iso-electric point of pI 6.5, showed haemagglutinating activity for bovine erythrocytes. This haemagglutinin (HA) inhibited the adherence of B. bronchiseptica to a rat lung cell line (L2) and was able to bind to N-acetylneuraminic acid. These findings suggest that the HA of B. bronchiseptica is an adhesin.

Sequence analysis of the nucleocapsid protein gene of rat coronavirus SDAV-681

The nucleotide sequence of the 3'-end of the genomic RNA of sialodacryoadenitis virus strain 681 (SDAV-681) was determined. A large open reading frame encoding a 454-amino-acid protein was identified as the nucleocapsid protein (N) gene, since the predicted protein is similar in size, chemical properties, and amino acid sequence to the N proteins of other coronaviruses. The amino acid variance of the N proteins between SDAV and mouse hepatitis virus (MHV) is not markedly different from that among MHV strains. A high degree of genetic relatedness between SDAV and MHV was revealed in the intergenic and 3'-noncoding sequences as well as in the N gene.

Sequence analysis and molecular detection of mouse hepatitis virus using the polymerase chain reaction

Sequence analysis of the nucleocapsid protein genes of five strains of mouse hepatitis virus (MHV) disclosed that the 3' region of the nucleocapsid protein gene contains highly conserved sequences unique to MHV. We designed a pair of primers to amplify cDNA from such sequences of MHV by using the polymerase chain reaction (PCR). Six isolates of wild-type MHV, as well as prototype viruses, were amplified successfully and detected in ethidium bromide-stained agarose gels. The sequence identity of PCR products was readily verified by confirming target size and a MflI site within the target. The sensitivity of our PCR assay was estimated to be sufficient to detect a single cell infected with MHV. This new approach may permit more sensitive and rapid detection of MHV in biologic materials than current methods such as virus isolation, the infant mouse bioassay, and the mouse antibody production test.

Detection of mouse hepatitis virus antibody by protein A-ELISA in 6 prevalent inbred strains or outbred stocks of mice

Protein A was applied as a reagent for the secondary reaction in ELISA (protein A-ELISA). Mouse hepatitis virus antibody in 6 prevalent mouse strains or stocks reared in a MHV-contaminated room was effectively detected by protein A-ELISA, whereas significant strain differences in the antibody detection rate were demonstrated using the complement fixation test. C57BL/6 mice were particularly reactive in the protein A-ELISA test.

A serological survey on Bacillus piliformis infection in laboratory rabbits in Japan

A total of 544 rabbit sera obtained from 6 commercial breeding facilities and 9 research institutions during 1985-1990 were tested for Bacillus piliformis antibody by an enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescent antibody test (IFAT). The antibody was detected in 53 (14.2%) rabbits from 3 breeding facilities and 30 (17.4%) rabbits from 6 research institutions, indicating the prevalence of B. piliformis infection among laboratory rabbits in Japan. The overall agreement with ELISA for immune status was 96.9% (527/544) with IFAT. In tests of the ability of ELISA and IFAT to quantitate antibody, a correlation coefficient (r) of 0.86 (P less than 0.01) was obtained by plotting the measured average log of the ELISA titer against the corresponding log of the IFAT titer.

Determination of an antigen suitable for enzyme-linked immunosorbent assay of the antibody to Bordetella bronchiseptica in guinea pigs

To establish an enzyme-linked immunosorbent assay (ELISA) technique for the serological diagnosis of infections caused by Bordetella bronchiseptica (B. bronchiseptica) in guinea pigs, the authors recently assessed the usefulness of three antigen preparations derived from the bacterial cell components: sonication antigen (S-Ag), cell surface antigen (C-Ag) and lipopolysaccharide antigen (L-Ag). The use of S-Ag for ELISA resulted in the most sensitive detection of the antibody to B. bronchiseptica from guinea pig sera immunized with killed bacteria and sera derived from naturally infected guinea pigs. Like C-Ag, S-Ag was highly specific, showing no cross-reactivity with Pasteurella multocida. Assessment of antibody formations in animals with experimentally induced infection using the three antigen preparations revealed that the antibody to S-Ag was formed earlier than antibodies to the other two antigen preparations following growth of the bacterium in the lungs. These results indicate that ELISA with S-Ag as an antigen is a useful tool for the serological diagnosis of infection by B. bronchiseptica.

Studies on the development of an ELISA kit for microbiological monitoring. 2. Improvement of the prototype ELISA kit with special references to mouse hepatitis virus antigen

Improvement of the mouse hepatitis virus (MHV) antigen in a prototype ELISA kit was performed. Equivalent divalent antigens of MHV Nu-67 and S strains with a protein concentration of 10 micrograms/ml showed the best sensitivity and specificity for the detection of MHV and sialodacryoadenitis/Parker's rat coronavirus antibodies in mice and rats, respectively. An increase in the reliability of macroscopic evaluation of both antibody tests is expected by using the newly manufactured kit with the improved antigen.

Sensitive detection of Mycoplasma pulmonis by using the polymerase chain reaction

Detection of Mycoplasma pulmonis was examined by using the polymerase chain reaction (PCR) for amplifying a specific DNA sequence. In gel electrophoresis which was conducted to detect the amplified products, only 1 pg of M. pulmonis DNA could be detected following 30 cycles of amplification, while no amplified product was detected even from 1 microgram of M. arthritidis or M. neurolyticum DNA. Furthermore, 10 colony-forming units of M. pulmonis could be detected by direct amplification from the mycoplasma suspension. These results suggest the usefulness of the PCR as a highly sensitive, specific, and rapid method for direct detection of M. pulmonis.

Studies on the development of an ELISA kit for microbiological monitoring. 1. Evaluation of the reliability of the prototype kit by field tests

The prototype of an ELISA kit using protein A as the second reaction reagent for mice and anti-rat IgG for rats was prepared for seromonitoring of the Sendai virus and mouse hepatitis virus (MHV)/sialodacryoadenitis virus (SDAV)/Parker's rat coronavirus (PCV) infections. The respective antigen strains and protein concentrations were Sendai virus MN strain, 2 micrograms/ml and MHV Nu-67 strain, 5 micrograms/ml. The reliability of this prototype kit was investigated in two field tests performed on a total of 10,094 mouse and rat sera from 147 institutions. The results indicated that the two types of kits for the two species of animals were highly specific, but it is necessary to increase the detection sensitivity of the MHV antigen for the MHV antibody of mice and SDAV/PCV antibodies of rats.

A DNA probe for specific detection of Mycoplasma pulmonis

Mycoplasma pulmonis was specifically detected by using a 2.3 kilobase pair (kbp) cloned DNA fragment derived from M. pulmonis m 53 as a probe. This probe recognized 2.3-kbp DNA fragments of three M. pulmonis strains in Southern hybridization, while it did not hybridize with the DNA of M. arthritidis or M. neurolyticum. Determination of the sensitivity of the probe by dot hybridization revealed that 10 ng of M. pulmonis DNA was detected by a biotinylated probe and 1 ng of M. pulmonis DNA was detected by a radioactive probe.

Genomic DNA analysis of rodent mycoplasmas

Genomic DNA was compared between three typical species of rodent mycoplasmas, Mycoplasma pulmonis, M. arthritidis and M. neurolyticum, and between strains of these species. Each of the three species showed a distinct restriction endonuclease cleavage pattern of genomic DNA. The genetic heterogeneity of these species was revealed by total DNA hybridization as well. In addition, the restriction endonuclease cleavage pattern of genomic DNA was almost identical in three strains of M. pulmonis and in two strains of M. neurolyticum. The genetic hemogeneity among strains of the same species was revealed by total DNA hybridization as well. These data suggest that the genomic DNA sequence of each rodent mycoplasma species has a high degree of species specificity.

[The reactivity of antigens of Mycoplasma pulmonis derived from mice and rats to naturally infected rat sera]

The reactivity of antigens of 4 mouse and 3 rat derived Mycoplasma pulmonis strains to 20 naturally infected rat sera was studied. The optical density values of the same serum by enzyme-linked immunosorbent assay using the 7 strains as the antigen revealed no marked difference among the strains. M. pulmonis antigens recognized by the antibodies were analyzed by the Western immunoblot method. The antigens with molecular weights of 92 K, 66 K, and 58 K were recognized in the 7 strains at a high frequency.

Expression of Mycoplasma pulmonis antigens in Escherichia coli

The expression of Mycoplasma pulmonis antigen in Escherichia coli was investigated by cloning genomic DNA derived from M. pulmonis m 53, and the DNA fragment participating in antigen expression was identified. When the DNA library of M. pulmonis was screened by colony immunoassay using anti-M. pulmonis serum, 10 recombinant clones expressing seroreactive antigens were obtained. The recombinant plasmids isolated from these clones included 3.7-6.5 kilobase pair (kbp) DNA inserts, while all clones contained a common 2.3-kbp DNA fragment. Subcloning of initial DNA inserts showed that the common 2.3-kbp fragment is essential for antigen expression. Moreover, antiserum against the recombinant antigen generated from the 2.3-kbp DNA fragment recognized a native M. pulmonis antigen. The reactivity of this antiserum was absorbed specifically with M. pulmonis. These results suggest that the cloned 2.3-kbp DNA fragment codes an antigen specific to M. pulmonis.

A plethysmographic technique for direct measurement of airway resistance in hamsters

We have developed a new technique to directly measure airway resistance (Raw) in small animals with a pressure-type body plethysmograph equipped with a hot-wire microflow sensor. Seventeen male golden hamsters weighing 70-84 g were studied. Change in alveolar pressure (delta PA) was calculated from total gas volume and the respired volume difference through the flow sensor between the midpoints of the tidal excursion curve, reflecting the thorax movement. The ratio of delta PA to the flow difference between those two midpoints gave Raw. Raw was compared with pulmonary resistance, and inspiratory and expiratory resistances were also compared. Raw was 0.44 +/- 0.06 (SE) cmH2O.ml-1.s. Mean of the coefficients of variation of Raw was 19.6 +/- 3.2% (SE). Raw was well correlated with pulmonary resistance (r = 0.93). We demonstrated that Raw could be directly measured in small animals with a hot-wire flow sensor and a plethysmographic technique, and the values were well correlated with previously reported pulmonary resistance.

Cross reactivity of Mycoplasma pulmonis and Mycoplasma arthritidis antigen strains to anti-Mycoplasma pulmonis antibody in the sera of Mycoplasma pulmonis infected rats

Reactivity of Mycoplasma pulmonis (Mp) antigen strains to anti-Mp antibody in the sera of Mp infected rats was examined by enzyme linked immunosorbent assay (ELISA). Antibody titers to 7 kinds of Mp antigens were measured in the sera of 20 Mp isolated rats and 20 Mp free rats by ELISA and complement fixation test (CF test). ELISA showed that there was no difference in the antibody titer of the same serum among 7 Mp antigen strains employed, and the main cross reaction to anti-Mp antibody took place on the common recognition site (common antigen) in all the Mp antigens. The CF test suggested that the antibody titers largely differed due to the kind of Mp antigen strains, and the detection rate was between 0 and 60%, presumably due to the difference in the reactivity or binding ability of complements but not due to the difference in the cross reactivity of Mp antigen to anti-Mp antibody. When the cross reactivity of anti-Mp antibody to Mycoplasma arthritidis (Ma) antigen was examined in the sera of 33 Mp isolated rats, the CF test exhibited the negative results, but ELISA showed 4 positive cases to support the cross reactivity of anti-Mp antibody to Ma antigen.

Solid-phase enzyme immunoassay for anti-mite IgE and IgG antibodies in allergic patients

Solid-phase enzyme immunoassays for the measurement of anti-mite IgE and IgG antibodies in the sera of mite-allergic patients were developed. In both assays, microtiter plates coated with the crude extract of Dermatophagoides farinae were used. The solid-phase enzyme immunoassay detected mite-specific IgE and IgG antibodies in sera of 18 and 15 out of 20 allergic patients, respectively. The correlation coefficient between the two antibody titers in patients' sera was 0.74, which was statistically significant (P less than .01). Both of the assays require no special facilities for radioactive materials and are considered to be useful in practice for the diagnosis of allergy to house dust mites by combining the results of the two assays.

Detection of Sendai virus antibody in mouse and guinea pig sera by an enzyme-linked immunosorbent assay with protein A

An enzyme-linked immunosorbent assay using horseradish peroxidase (HRPO)-labeled protein A (P-ELISA) was established for detection of Sendai virus (SV) antibody in mouse and guinea pig sera. Sensitivity and specificity of P-ELISA were compared with those of ordinary ELISA using HRPO-labeled immunoglobulin G (IgG-ELISA) and the hemagglutination inhibition (HI) test. P-ELISA was 100 to 1,000 times more sensitive than the HI test for detection of the antibody in SV-naturally infected mice. P-ELISA and IgG-ELISA showed similar sensitivities for detection of the antibody in naturally infected mouse and guinea pig sera. A high specificity was demonstrated in P-ELISA with a cut-off optical density value of 0.2 (492 nm), while a non-specific reaction was observed when IgG-ELISA was used to both mouse and guinea pig sera at a low dilution (1:10-20). The antibody in rat sera was not detected by P-ELISA although it was realized by IgG-ELISA.

IgE-isotype-specific suppressor cells in the mouse: characterization using tetraparental chimera mice of high (DBA/2) and low (SJL) IgE responder embryos

Tetraparental chimera mice were developed by aggregation of IgE high responder (DBA/2) and IgE low responder (SJL) embryos. Anti-dinitrophenyl (DNP) IgE antibody response in such mice (SJL----DBA/2) upon challenge with DNP-keyhole-limpet hemocyanin (KLH) in alum was clearly suppressed, while anti-DNP IgG antibody response was not. High-titer anti-DNP IgE and IgG antibody response developed in F1 hybrid mice of SJL and DBA/2 (SDF1) mice. The experimental results suggest that high IgE antibody production is the dominant trait, and the IgE-specific suppressor gene in SJL mice is autosomal recessive. IgE-specific suppressor T cells in SJL mice actively suppressed IgE antibody formation by DBA/2 immuno-competent cells across the histocompatibility barrier. Hapten-specific B cells and carrier-specific T cells were prepared in SJL----DBA/2 and SDF1 mice by immunization with DNP-KLH or ovalbumin (OA) in alum and transferred to irradiated SDF1 mice followed by challenge with DNP-OA. Hapten-specific B cells and carrier-specific helper T cells clearly developed in SDF1 mice. Recipient mice transferred with DNP-KLH-primed SDF1 spleen cells and OA-primed SDF1 spleen cells showed high-titer anti-DNP IgE and IgG antibody responses. OA-primed SJL----DBA/2 spleen cells cotransferred with DNP-KLH-primed SDF1 spleen cells and OA-primed SDF1 spleen cells completely abolished secondary anti-DNP IgE antibody response. The data suggest that carrier-specific helper T cells for IgE and IgG antibody responses are distinct. The regulatory role of IgE-isotype-specific suppressor cells were considered to be the interference of cooperative cellular interaction between IgE B cells and carrier-specific, IgE-specific helper T cells.

Cyclosporin A-induced suppression of ongoing IgE antibody formation in the mouse

Persistent anti-ovalbumin (OA) IgE antibody formation in the mouse was suppressed by oral administration of cyclosporin A (Cy A). Spontaneous anti-OA IgE antibody formation in vitro was also suppressed by Cy A added to the culture. Anti-OA IgG antibody responses in vivo and in vitro were less affected by Cy A. Cy A-induced immunosuppression was T cell-dependent since removal of T cells from the immune spleen cell suspension abolished the Cy A-induced suppression of antibody formation. Supplementing normal spleen T cells resulted in recovery of Cy A-induced suppression of spontaneous antibody formation in vitro. Cy A-induced suppressor T cells carried both Lyt 1 and Lyt 2 surface markers.

Interstitial pneumonitis in autoimmune MRL/lpr mice and its treatment with cyclosporin A

Age-associated changes of anti-double-stranded (ds) DNA antibodies, anti-single-stranded (ss) DNA antibodies, and serum immune complex concentrations were studied in MRL/lpr mice. All anti-ds DNA antibodies, anti-ss DNA antibodies, and immune complexes began to be detected in the sera of MRL/lpr mice aged 8 to 13 weeks and increased remarkably after 17 weeks of age. Almost no pathological findings were observed histologically in the lungs of MRL/lpr mice aged 8 weeks but interstitial pneumonitis became evident at 14 weeks of age. Peribronchial and perivascular lymphocyte infiltrations were seen in the lungs of 14-week-old MRL/lpr mice and became more severe at 21 weeks of age. Oral administration of cyclosporin A to 15-week-old MRL/lpr mice markedly prolonged their life span. The lungs of 44-week-old MRL/lpr mice given cyclosporin A showed few pathological findings except for minimal perivascular lymphocyte infiltration.

A solid-phase enzyme immunoassay for anti-insulin antibody in diabetes mellitus patients

A solid-phase enzyme immunoassay for the measurement of anti-insulin antibodies in the sera of patients with diabetes mellitus was developed. Porcine insulin conjugated with bovine serum albumin was used for coating microtiter plates. This assay was as sensitive as the conventional radioimmunoassay. Anti-insulin antibody titers measured by the enzyme immunoassay and conventional radioimmunoassay correlated well and the correlation coefficient was 0.920, which was statistically significant (P less than 0.001). The enzyme immunoassay detected anti-insulin antibody in 23 out of 35 sera of patients with insulin-dependent diabetes mellitus. The present enzyme immunoassay does not require radioactive materials, is less expensive and is concluded to be practically useful.

A solid-phase enzyme immunoassay for anti-acetylcholine receptor antibody in myasthenia gravis patients

A solid-phase enzyme immunoassay for the measurement of anti-acetylcholine receptor antibodies in the sera of patients with myasthenia gravis is reported. Sufficient amounts of acetylcholine receptor for the sensitive detection of anti-acetylcholine receptor antibody were directly fixed to Costar serocluster 96-well EIA plates coated with poly-L-lysine hydrobromide. The solid-phase enzyme immunoassay detected anti-acetylcholine receptor antibodies in 91% of the myasthenia gravis patients including 4 out of 4 ocular type myasthenia patients, anti-acetylcholine receptor antibodies of which were not detectable by the immunoprecipitation assay. Correlation between antibody titers measured by enzyme immunoassay and the immunoprecipitation assay was significant.