Heterogeneous behavior of anti-beta2-glycoprotein I antibodies on various commercially available enzyme immunoassay plates coated with beta2-glycoprotein I

OBJECTIVE

To evaluate commercially available enzyme immunoassay (EIA) plates for the measurement of anti-beta2-glycoprotein I autoantibody (anti-beta2-GPI).

METHODS

Sera from 10 patients with the antiphospholipid syndrome, and 3 monoclonal anti-beta2-GPI antibodies established from patients with antiphospholipid syndrome, were assayed for binding to solid phase beta2-GPI on 20 commercially available plates.

RESULTS

Several commercially available EIA plates were found to be of potential value for the measurement of anti-beta2-GPI autoantibody. Some plates were unsuitable for anti-beta2-GPI detection, possibly due to less beta2-GPI on the plates, or to differences in the nature of conformational changes of beta2-GPI induced by the plates.

CONCLUSION

Differences among EIA plates need to be considered when measuring beta2-GPI antibodies.

Generation of an autologous tissue (matrix) flap by combining an arteriovenous shunt loop with artificial skin in rats: preliminary report

The present experiment was designed to investigate the possibility of prefabricating a tissue flap in a rat by combining an arteriovenous (A-V) shunt loop with artificial skin dermis (AS). The A-V fistula loop was constructed between the right femoral artery and vein by the interposition of a vein graft and the loop was wrapped with a folded sheet of AS and buried beneath the inguinal skin. In the control group the folded sheet of AS was inserted without a vessel loop and embedded in the inguinal region as in the experimental group. There were three experiments. In experiment 1, the total volume of the generated tissue formed within the AS was calculated after 4 weeks in the experimental and control groups. In experiment 2, the AS in the experimental group was harvested at 2 (group 1) and 4 (group 2) weeks after insertion to assess the change in morphology over time. In experiment 3, full thickness skin grafts were placed over the generated tissue of the experimental groups to investigate the possibility of creating skin flaps. The total volume of tissue generated in the experimental group was significantly greater than in the control group (P< 0.01). Histological and carbon injection studies suggest that the new capillary bed is derived from the graft loop vessels and tissue generation and organisation of the AS were further advanced in group 2 than in group 1. The skin grafts placed over the tissues generated showed complete survival and could be raised as island flaps in both groups.

The mechanism of a human reaction to vibration stress by palmar sweating in relation to autonomic nerve tone

OBJECTIVES

To clarify the mechanism of a human reaction to vibration stress by palmar sweating in relation to the autonomic nerve tone.

METHODS

The autonomic nerve tone was divided into four types by using digital photoelectroplethysmography (PTG) with auditory stimuli: normal (N), hyperreactive (I and D), and hyporeactive (P) types. Palmar sweating and digital PTG were simultaneously measured on the right palm and middle finger, respectively, in 20 healthy men. The left hand gripping the handle with a grasp strength of 49 N was exposed to vibration at a frequency of 125 Hz and acceleration magnitudes of 0 m/s2 (as a control), 30 m/s2, or 50 m/s2 for 3 min. The volume of palmar sweating was recorded before, during, and 30 min after vibration load. Three kinds of drugs related to the autonomic nervous system were orally administered to the subjects. Then 80 min after administration, the experiments were repeated.

RESULTS

Of 20 subjects, 17 showed normal autonomic nerve tone (N type), and 3 hyperreactive (I type). The palmar sweating reaction to vibration in I-type subjects was greater and lasted longer than that in N-type subjects. Vibration with an acceleration of 50 m/s2 produced the greatest reaction which was about 7 times larger than that at 0 m/s2 and 2.5 times that at 30 m/s2 (P < 0.01). Sulpiride decreased palmar sweating during vibration, while prazosin and scopolamine inhibited it.

CONCLUSIONS

The palmar sweating reaction to vibration stress was related to the background level of the autonomic nerve tone. The sweating volume was in direct proportion to the acceleration magnitude of vibration. The reaction of palmar sweating to vibration stress may be mediated through both the adrenergic and cholinergic fibers of the autonomic nervous system.

A chimeric antibody with the human gamma1 constant region as a putative standard for assays to detect IgG beta2-glycoprotein I-dependent anticardiolipin and anti-beta2-glycoprotein I antibodies

OBJECTIVE

Thromboembolic manifestations or thrombocytopenia in association with anticardiolipin antibodies (aCL) or lupus anticoagulant are known as the antiphospholipid syndrome (APS). Efforts have been made to elucidate precise clinical features and adequate therapeutic options for treating patients with APS. However, the lack of a proper international standard for measurement of aCL makes it difficult to compare data derived from different laboratories. We attempted to design a chimeric antibody with human gamma constant regions and variable regions of WBCAL-1, a monoclonal antibody established from an APS-prone mouse which has a specificity similar to that of aCL in sera from humans with APS.

METHODS

Variable-region genes of WBCAL-1, which were cloned using reverse transcription-polymerase chain reaction, were inserted into plasmids containing human gamma1 and kappa constant-region genes. The construct was transfected to a mouse myeloma cell line. Stable transfectants that secreted a chimeric antibody, HCAL, into the culture supernatant were obtained. The reactivity of HCAL to cardiolipin and to beta2-glycoprotein I (beta2GPI) was studied using a solid-phase enzyme immunoassay. The binding of HCAL was compared with the binding of standards for IgG aCL and anti-beta2GPI antibody assays done in 18 independent laboratories.

RESULTS

In the presence of beta2GPI, HCAL bound to the wells of cardiolipin-coated microtiter plates in a dose-dependent manner and reacted with beta2GPI on oxygenated polystyrene plates. The aCL activity of HCAL can be converted into GPL units (IgG phospholipid units), which is widely used to quantify IgG aCL activity, using the following formula: 1 GPL unit = 32.9 x (concentration of HCAL [in microg/ml])(0.503). The reactivity of HCAL to cardiolipin or beta2GPI was similar to the reactivity of standards for IgG aCL or anti-beta2GPI antibody assays done in collaborative laboratories.

CONCLUSION

Because the reactivity of HCAL is similar to that of aCL in sera from humans with APS, HCAL will be useful as a standard for human IgG aCL and anti-beta2GPI antibody assays.

Reflex sympathetic dystrophy in a patient with the antiphospholipid syndrome

We describe a 50-year-old woman who developed severe pain of the left lower limb after an episode of thrombophlebitis. Bone scintigraphy and thermography showed results indicative of reflex sympathetic dystrophy. Laboratory analysis revealed the presence of the lupus anticoagulant. The patient was diagnosed as antiphospholipid syndrome complicated with reflex sympathetic dystrophy of the left lower limb. To our knowledge, this is the first report of a patient with reflex sympathetic dystrophy with underlying antiphospholipid syndrome.

Hypocomplementemia correlates with intrauterine growth retardation in systemic lupus erythematosus

PROBLEM

The aim of this study was to elucidate fetomaternal risks in systemic lupus erythematosus (SLE)-complicated pregnancy.

METHOD OF STUDY

Pregnancy course, complications, and fetal outcome in 82 pregnancies of 55 patients with SLE were investigated.

RESULTS

These 82 pregnancies resulted in 14 fetal losses and 66 live births. Without clinical manifestation of SLE-flare, 4 of 8 patients who had low serum complement activity during the pregnancies delivered small-for-date neonates. The rate of the intrauterine growth retardation was significantly higher than that observed in pregnancies with normal complement activity. The frequency of premature deliveries (60%) in patients who received more than 15 mg/day of prednisolone was significantly high when compared with pregnancies maintained by 0-15 mg/day (13.1%).

CONCLUSIONS

These data demonstrate the preconceptional and perinatal management necessary in SLE and suggest that the pregnancy with hypocomplementemia, the disease activity, and/or a relatively high maintenance dose of corticosteroid should be carefully managed and monitored.

Correlation between beta2-glycoprotein I valine/leucine247 polymorphism and anti-beta2-glycoprotein I antibodies in patients with primary antiphospholipid syndrome

OBJECTIVES

Beta2-Glycoprotein I (beta2GPI) exon 7 polymorphism leads to a valine leucine amino acid exchange at position 247 in domain 5 of beta2GPI, between the phospholipid binding site and the cryptic site of the epitopes for anti-beta2GPI antibodies. Therefore, position 247 polymorphism may affect the conformational change of beta2GPI and the exposure of the epitopes for anticardiolipin antibodies (aCL) (= anti-beta2GPI antibodies). In this study we analysed the genetic polymorphism of beta2GPI in a British cohort of well-defined antiphospholipid syndrome (APS) patients.

METHODS

This study comprised 88 Caucasoid patients with APS [57 with primary APS and 31 with APS secondary to systemic lupus erythematosus (SLE)]. Polymorphism assignment was determined by polymerase chain reaction followed by allele-specific restriction enzyme digestion (PCR-RFLP). The presence of anti-beta2GPI antibodies was detected by ELISA utilizing irradiated ELISA plates.

RESULTS AND CONCLUSIONS

Anti-beta2GPI antibodies were present in 28 of 57 primary APS patients (49%) and in 19 of 31 secondary APS patients (61%). The allele containing valine247 was significantly more frequent in primary APS patients with anti-beta2GPI antibodies than in controls (OR = 2.51, 95%, CI 1.03-6.13, P = 0.0396) or in primary APS patients without anti-beta2GPI antibodies (OR = 2.92, 95% CI 1.16-7.39, P = 0.0204). This tendency was not found in the secondary APS group. In conclusion, the beta2GPI polymorphism, valine/leucine247, is correlated with anti-beta2GPI antibody production in patients with primary APS, and valine247 may be important in the formation of beta2GPI antigenicity.

Association between job characteristics and plasma fibrinogen in a normal working population: a cross sectional analysis in referents of the SHEEP Study. Stockholm Heart Epidemiology Program

STUDY OBJECTIVE

To explore the association between job characteristics and plasma fibrinogen concentrations.

DESIGN

Cross sectional design.

SETTING

The Greater Stockholm area.

SUBJECTS

A total of 1018 men and 490 women aged 45-70 who were randomly selected from the general population during 1992-1994. They were all employed and had no history of myocardial infarction.

MAIN RESULTS

The self reported job characteristics were measured by a Swedish version of the Karasek demand-control questionnaire. For inferred scoring of job characteristics, psychosocial exposure categories (job control and psychological demands) were assigned by linking each subject's occupational history with a work organisation exposure matrix. Job strain was defined as the ratio between demands and control. In univariate analyses, expected linear trends were found in three of four tests of association between high plasma fibrinogen and low control (the self reported score for women and the inferred score for both sexes), in one of four tests of association between high plasma fibrinogen and high demands (the inferred score for women) and in two of four tests of association between high plasma fibrinogen and job strain (the inferred score for both sexes). Multiple logistic regression analyses showed that men in the inferred job strain group have an increased risk of falling into the increased plasma fibrinogen concentration group (above median level of the distribution) (odds ratio (OR) 1.2; 95% CI 1.0, 1.5) after adjustment for the variables that were associated with plasma fibrinogen in the univariate analyses. In women, low self reported control, high inferred demand, and inferred job strain were significantly associated with increased plasma fibrinogen concentration (OR 1.3; 95% CI 1.0, 1.8, OR 1.5; 95% CI 1.0, 2.2, OR 1.5; 95% CI 1.1, 2.2, respectively).

CONCLUSIONS

These results indicate that adverse job characteristics may be related to plasma fibrinogen concentrations and this relation is more relevant in female workers. The clearest evidence for psychosocial effects on plasma fibrinogen seems to be with job control and the associations are clearer for the objective than for the self report variables.

Cystic lymphoepithelial lesions of the pancreas and peripancreatic region: report of two cases

Two cases of an extremely rare cystic lymphoepithelial lesion of a lymph node associated with the pancreas are presented herein. The first patient was a 57-year-old woman with a serous cystoadenoma who underwent resection of the body and tail of pancreas, and the other patient was a 75-year-old woman with cancer of the papilla of Vater who underwent pylorus-preserving pancreatoduodenectomy. Both lesions were incidentally found during pathologic examination of lymph nodes from the peripancreatic region. Histologically, there were many scattered nests of the lymphoepithelial lesion in the lymphoid stroma, each of which was lined with stratified squamous epithelium. The pathological structure was found to resemble the lymphoepithelial lesion of the pancreas. Although the histogenesis is unknown, we hypothesize that the lesion might have arisen from squamous metaplasia of a benign epithelial inclusion such as the pancreatic duct of an ectopic pancreas in a peripancreatic lymph node. Therefore, a cystic lesion formed as a result of keratinization of the squamous epithelium with invasion into the pancreas could become a lymphoepithelial cyst of the pancreas.

Lipoprotein(a) levels and apolipoprotein(a) isoforms related to life style risk factors

Lipoprotein(a) [Lp(a)] has been considered to be a predictor of premature coronary heart disease and other cardiovascular diseases. Lp(a) levels are largely genetically determined, but the detailed mechanism of Lp(a) elevation is uncertain. We examined the association between Lp(a) levels and apolipoprotein(a) [apo(a)] phenotypes as well as that of Lp(a) level and other various conditions. The subjects were 280 healthy Japanese (102 males and 178 females) aged 39 to 70 years who were living in a rural community in 1992. We obtained apo(a) phenotypes determined by SDS-PAGE as well as Lp(a) levels and other cardiovascular risk factors. We combined apo(a) phenotypes form 4 groups according to molecular weights (from high apo(a) molecular weight to low: I, II, III and IV). Lp(a) levels were associated with apo(a) phenotype-groups, that is, they were inversely associated with apo(a) molecular weight. Small apo(a) phenotypes were less frequent than large ones. The median Lp(a) level was higher in smoking (29.2 mg/dL) than in non-smoking subjects (18.5 mg/dL) in phenotype-group III. Adjusted means of total cholesterol and fibrinogen levels in apo(a) phenotype-group IV were the highest of all phenotype-groups. Age, apo(a) phenotype, smoking status, total cholesterol and fibrinogen were positively correlated with Lp(a) levels by multiple regression analysis. Lp(a) levels were found to be mainly associated with apo(a) phenotype, but varied broadly within the same apo(a) phenotype at various conditions, such as smoking status and high total cholesterol.

Job strain and biological coronary risk factors: A cross-sectional study of male and female workers in a japanese rural district

To investigate the association between job strain and biological coronary risk factors, a demand-control questionnaire was applied to 138 male (mean age 51.5) and 166 female (50.8) workers in Japanese rural town. In Model I, workers rated as both above the median on demands and below the median on control were defined as a strain group and compared to the rest. In Model II, the effect of a multiplicative term of demands by control was tested once the component main effects were controlled. In both models, possible confounders were controlled. Men in the strain group had higher blood glucose than did the others (Model 1), and the multiplicative term was significantly associated with diastolic blood pressure in men and with Lipoprotein(a) in women (Model II). The results suggest that the demand-control model predicts coronary risk factors in Japanese rural workers, and the associations are different between genders.

Epitopes on beta2-GPI recognized by anticardiolipin antibodies

Anticardiolipin antibodies (aCL) found in sera from patients with antiphospholipid syndrome recognize a cryptic epitope that appears on the beta2-glycoprotein I (beta2-GPI) molecule when beta2-GPI interacts with a lipid membrane composed of negatively charged phospholipid or when beta2-GPI is adsorbed on a polyoxygenated polystyrene plate. A homology based model of beta2-GPI was constructed based on the NMR coordinates of sushi domains of human factor H. The conformation was like a cylinder consisting of five domains, its IV and V domains being glued by electrostatic interaction. We used phage-displayed random peptide libraries to search the epitopes of human aCL. Structures similar to consensus sequences selected by a biopanning method was found on domain IV of beta2-GPI.

Anti-beta2-glycoprotein I antibodies

The relationship between presence of anti-beta2-glycoprotein I autoantibodies (abeta2-GPI) and history of thrombosis is now widely known. However, differences in the methodology of abeta2-GPI detection have made the comparison of data from different laboratories extremely difficult. We discuss the significance of abeta2-GPI of the IgG, IgM and IgA isotypes, and our approach to developing an easier and more reproducible method for the detection of this autoantibody. In addition, we present data that shows that commercially available enzyme immunoassay plates differ regarding detectability of abeta2-GPI. Since the clinical significance of this heterogeneity is presently unclear, the set-up of the detection systems and interpretation of data need great care.

Health-related behaviors, social support, and community morale

The relation among health behaviors, social support, and community morale--attitudes toward one's community, such as attachment and social participation--was examined in 597 adults living in a Japanese community. Logistic models revealed that strong spousal support was related to reduced alcohol drinking and enhanced family support was related to a reduction in smoking. The support of friends was positively associated with the frequency of alcohol drinking by men. Among women, family support was positively related to the frequency of consuming Japanese-style food. Community morale was positively associated with consuming Japanese-style side dishes and negatively associated with alcohol consumption. The results indicate that there are varied associations between social relationships and health-related behavior and that these associations are gender-related. Knowing the specific associations between an individual's social relationships and his or her health-related behavior will he helpful for community-based intervention.

Whole-body vibration suppresses gastric motility in healthy men

The influence of whole-body vibration on gastric motility was investigated by using an electrogastrography (EGG) in seven healthy men. The EGG is usually referred to as a noninvasive technique of recording gastric myoelectrical activity by means of placing electrodes on the abdominal surface. Sinusoidal vertical vibration at each of 3 different frequencies (10 Hz, 20 Hz, 40 Hz) were randomly given to the subject seated on a platform of vibrator for 5 min. The vibration magnitude was kept at a constant of 2.0 msec-2 (r.m.s.) during operation. The mean dominant frequency of EGG at control period was prior to operation 3.3 cycles per min (cpm). During vibration exposure at 10 Hz, the peak of dominant frequency increased to 3.9 cpm, and the relative power of slow wave showed the statistically significant decrease (45.8%, p < 0.05). The mean relative power of slow wave which is composed of frequencies ranged from 2.0 to 5.0 cpm was 56.6% at control period. On the contrary the mean relative power of frequencies ranging from 5.0 to 9.0 cpm, tachygastria increased from 29.5% to 39.1%. These results suggest that the short-term exposure to whole-body vibration effects on the gastric myoelectrical activity.

Decision latitude, job strain, and myocardial infarction: a study of working men in Stockholm. The SHEEP Study Group. Stockholm Heart epidemiology Program

OBJECTIVES

This study examined the role of decision latitude and job strain in the etiology of a first myocardial infarction.

METHODS

Eligible case patients were all full-time working men 45 to 64 years of age who suffered a first myocardial infarction during the period January 1992 to January 1993 in the greater Stockholm region. Referents were selected from the general population. Participation rates were 82% (case patients) and 75% (referents).

RESULTS

Both inferred and self-reported low decision latitude were associated with increased risk of a first myocardial infarction, although this association was weakened after adjustment for social class. A decrease in inferred decision latitude during the 10 years preceding the myocardial infarction was associated with increased risk after all adjustments, including chest pain and social class. The combination of high self-reported demands and low self-reported decision latitude was an independent predictor of risk after all adjustments.

CONCLUSIONS

Both negative change in inferred decision latitude and self-reported job strain are important risk indicators in men less than 55 years of age and in blue-collar workers.

IgA class anti-beta2-glycoprotein I in patients with systemic lupus erythematosus

OBJECTIVE

To search for a possible relationship between the presence of IgA class anti-beta2-glycoprotein I antibody (abeta2-GPI) and clinical manifestations, including thrombotic episodes, in patients with systemic lupus erythematosus (SLE).

METHODS

Serum IgA abeta2-GPI levels in 124 Japanese patients with SLE were measured using a phospholipid independent enzyme immunoassay. Relationships to clinical histories and to various laboratory data including IgG and IgM class abeta2-GPI were examined.

RESULTS

Twenty-five percent of patients with SLE were positive for IgA abeta2-GPI. Patients with a history of thrombosis had significantly higher probabilities for positivity of IgA abeta2-GPI, compared to those without. The presence of IgA abeta2-GPI was correlated with presence of lupus anticoagulant and/or biological false positive result for serological syphilis test. Titer of IgA abeta2-GPI significantly correlated with values of IgG abeta2-GPI, IgM abeta2-GPI, and anti-DNA antibodies.

CONCLUSION

The presence of IgA abeta2-GPI may be related to the occurrence of thrombosis in patients with SLE. Measurements of IgA abeta2-GPI may be of value for evaluating risk of thrombosis in patients with SLE.