Selenium concentration and cardiovascular disease risk: Mendelian randomization study

Background/Introduction

Selenium has been associated with cardiovascular disease (CVD) risk in observational studies; however, the causality of the association remains unestablished.

Purpose

To examine the associations of selenium concentrations with 15 CVDs using Mendelian randomization analysis.

Methods

Genetic variants significantly associated with concentrations of toenail and blood (TAB) and blood selenium in mild linkage disequilibrium (r2 <0.3) were used as instrumental variables. Summary-level data for 15 CVDs were obtained from the UK Biobank study (n=367,561), FinnGen study (n=218,792), and six international consortia. The inverse variance weighted method accounting for linkage disequilibrium was used to estimate the associations. Results for one outcome from different sources were combined using the fixed effect meta-analysis method. Bonferroni correction was used to account for multiple testing, and associations with P value ≤0.003 (0.05 / 15 outcomes) were described as significant. Associations with P value between ≤0.05 and >0.003 were regarded as suggestive associations.

Results

Genetically predicted concentrations of TAB selenium were not significantly associated with the risk of the 15 CVDs. However, there were suggestive associations of genetically predicted higher concentrations of TAB selenium with increased risk of atrial fibrillation and peripheral artery disease. The odds ratio per one-unit increase in log-transformed concentrations of TAB selenium was 1.07 (95% confidence interval, 1.01–1.12; P=0.019) for atrial fibrillation and 1.20 (95% confidence interval, 1.05–1.38; P=0.008) for peripheral artery disease. We observed no associations between genetically predicted blood selenium concentrations and risk of the 15 CVDs.

Conclusions

Genetically predicted higher concentrations of TAB or blood selenium were not associated with a lower risk of CVD, which suggests that high selenium status may not prevent CVD development. The suggestive positive associations of TAB selenium with atrial fibrillation and peripheral artery disease warrants verification.

Funding Acknowledgement

Type of funding sources: None.

The dendrimer impact on vesicles can be tuned based on the bilayer charge and the presence of albumin

PAMAM (polyamidoamine) dendrimers are promising in biomedical applications that can interact with both the bilayer and . Here we employed giant unilamellar vesicles (GUVs) of two different charge densities to study the effect of albumin, one of the major in blood plasma, on the interactions between PAMAM dendrimers and membranes. The results show that albumin exacerbates the effect of dendrimers on the destabilization of the vesicles in terms of leakage, aggregation and collapse in particular for negatively charged vesicles while neutrally charged membranes are not affected. We conclude that the higher affinity of both albumin and PAMAM G6 towards negatively charged membranes explains their synergistic behavior in this case. In the case of neutral vesicles, the affinity between PAMAM G6 and albumin is stronger than that between PAMAM G6 (or albumin) and neutral vesicles, and thus no synergism is observed for the mixture during the interaction with neutral membranes.

Unraveling dendrimer translocation across cell membrane mimics

Poly(amidoamine) (PAMAM) dendrimers are promising candidates in several applications within the medical field. However, it is still to date not fully understood whether they are able to passively translocate across lipid bilayers. Recently, we used fluorescence microscopy to show that PAMAM dendrimers induced changes in the permeability of lipid membranes but the dendrimers themselves could not translocate to be released into the vesicle lumen. Because of the lack of resolution, these experiments could not assess whether the dendrimers were able to translocate but remained attached to the membrane. Using quartz crystal microbalance with dissipation monitoring and neutron reflectivity, a structural investigation was performed to determine how dendrimers interact with zwitterionic and negatively charged lipid bilayers. We hereby show that dendrimers adsorb on top of lipid bilayers without significant dendrimer translocation, regardless of the lipid membrane surface charge. Thus, most likely dendrimers are actively transported through cell membranes by protein-mediated endocytosis in agreement with previous cell studies. Finally, the higher activity of PAMAM dendrimers for phosphoglycerol-containing membranes is in line with their high antimicrobial activity against Gram-negative bacteria.

Dietary cadmium exposure and prostate cancer incidence: a population-based prospective cohort study

BACKGROUND

Experimental data convincingly propose the toxic metal cadmium as a prostate carcinogen. Cadmium is widely dispersed into the environment and, consequently, food is contaminated.

METHODS

A population-based cohort of 41 089 Swedish men aged 45-79 years was followed prospectively from 1998 through 2009 to assess the association between food frequency questionnaire-based estimates of dietary cadmium exposure (at baseline, 1998) and incidence of prostate cancer (3085 cases, of which 894 were localised and 794 advanced) and through 2008 for prostate cancer mortality (326 fatal cases).

RESULTS

Mean dietary cadmium exposure was 19 μg per day±s.d. 3.7. Multivariable-adjusted dietary cadmium exposure was positively associated with overall prostate cancer, comparing extreme tertiles; rate ratio (RR) 1.13 (95% confidence interval (CI): 1.03-1.24). For subtypes of prostate cancer, the RR was 1.29 (95% CI: 1.08-1.53) for localised, 1.05 (95% CI: 0.87-1.25) for advanced, and 1.14 (95% CI: 0.86-1.51) for fatal cases. No statistically significant difference was observed in the multivariable-adjusted risk estimates between tumour subtypes (P(heterogeneity)=0.27). For localised prostate cancer, RR was 1.55 (1.16-2.08) among men with a small waist circumference and RR 1.45 (1.15, 1.83) among ever smokers.

CONCLUSION

Our findings provide support that dietary cadmium exposure may have a role in prostate cancer development.

HIV care need not hamper maternity care: a descriptive analysis of integration of services in rural Malawi

OBJECTIVE

To evaluate the use of reproductive health care and incidence of paediatric HIV infection during the expansion of antiretroviral therapy and services for the prevention of mother-to-child transmission in rural Malawi, and the influence of integration of these HIV-related services into general health services.

DESIGN

Descriptive analysis.

SETTING

Thyolo District, with a population of 600,000, an HIV prevalence of 21% and a total fertility rate of 5.7 in 2004.

POPULATION

Women attending reproductive health services care in 2005 and 2010.

METHODS

Review of facility records and databases for routine monitoring.

MAIN OUTCOME MEASURES

Use of antenatal, intrapartum, postpartum, family planning and sexually transmitted infection services; incidence of HIV infection in infants born to mothers who received prevention of mother-to-child transmission care.

RESULTS

There was a marked increase in the uptake of perinatal care: pregnant women in 2010 were 50% more likely to attend at least one antenatal visit (RR 1.50, 95% CI 1.48-1.51); were twice as likely to deliver at a healthcare facility (RR 2.05, 95% CI 2.01-2.08); and were more than four times as likely to present for postpartum care (RR 4.40, 95% CI 4.25-4.55). Family planning consultations increased by 40% and the number of women receiving treatment for sexually transmitted infections doubled. Between 2007 and 2010, the number of HIV-exposed infants who underwent testing for HIV went up from 421 to 1599/year, and the proportion testing positive decreased from 13.3 to 5.0%; infants were 62% less likely to test HIV positive (RR 0.38, 95% CI 0.27-0.52).

CONCLUSIONS

During the expansion and integration of HIV care, the use of reproductive health services increased and the outcomes of infants born to HIV-infected mothers improved. HIV care may be successfully integrated into broader reproductive health services.

Reduced tuberculosis case notification associated with scaling up antiretroviral treatment in rural Malawi

OBJECTIVE

To report on the trends in new and recurrent tuberculosis (TB) case notifications in a rural district of Malawi that has embarked on large-scale roll-out of antiretroviral treatment (ART).

METHODS

Descriptive study analysing TB case notification and ART enrolment data between 2002 and 2009.

RESULTS

There were a total of 10,070 new and 755 recurrent TB cases. ART scale-up started in 2003, and by 2007 an estimated 80% ART coverage had been achieved and was sustained thereafter. For new TB cases, an initial increase in case notifications in the first years after starting ART (2002-2005) was followed by a highly significant and sustained decline from 259 to 173 TB cases per 100,000 population (χ(2) for trend 261, P < 0.001, cumulative reduction for 2005-2009 = 33%, 95%CI 27-39). For recurrent TB, the initial increase was followed by a significant drop, from 20 to 15 cases/100,000 (χ(2) for linear trend = 8.3, P = 0.004, constituting a 25% (95%CI 9-49) cumulative reduction between 2006 and 2009. From 2005 to 2009, ART averted an estimated 1164 (95%CI 847-1480) new TB cases and 78 (95%CI 23-151) recurrent TB cases.

CONCLUSIONS

High ART implementation coverage is associated with a very significant declining trend in new and recurrent TB case notifications at population level.

The effect of PAMAM G6 dendrimers on the structure of lipid vesicles

Dendrimers are polymers with unique properties that make them promising in a variety of applications such as potential drug and gene delivery systems. PAMAM dendrimers, in particular, have been widely investigated and are efficiently translocated into the cell. The mechanism of translocation, however, is still unknown. Recently it was proposed that PAMAM dendrimers are able to open holes in lipid bilayers by stealing lipid from the bilayer and forming "dendrisomes". The present work intends to contribute in the clarification of this question: why are dendrimers able to translocate into the cell? We create simple models for cell membranes by using small lipid vesicles that present a single lipid phase at physiologically relevant conditions. We then follow the effect that dendrimers have on the structure of the vesicles by using a combination of various techniques: dynamic light scattering, cryo-TEM and small angle X-ray scattering. We discuss our results with respect to the previous findings and reflect on their possible implications for real translocation in living cells.

Exposure to cadmium and persistent organochlorine pollutants and its association with bone mineral density and markers of bone metabolism on postmenopausal women

Environmental contaminants such as cadmium and persistent organochlorine pollutants have been proposed as risk factors of osteoporosis, and women may be at an increased risk. To assess associations between exposure to cadmium and two different POPs (2,2',4,4',5,5'-hexachlorobiphenyl CB-153, 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene p,p'-DDE), on one hand, and bone effects, on the other, in a population-based study among postmenopausal (60-70 years) Swedish women with biobanked blood samples. The study included 908 women and was designed to have a large contrast of bone mineral densities, measured with a single photon absorptiometry technique in the non-dominant forearm. Biochemical markers related to bone metabolism were analyzed in serum. Exposure assessment was based on cadmium concentrations in erythrocytes and serum concentrations of CB-153 and p,p'-DDE. Cadmium was negatively associated with bone mineral density and parathyroid hormone, positively with the marker of bone resorption. However, this association disappeared after adjustment for smoking. The major DDT metabolite (p,p'-DDE) was positively associated with bone mineral density, an association which remained after adjustment for confounders, but the effect was weak. There was no evidence that the estrogenic congener (CB-153) was associated with any of the bone markers. In conclusion, no convincing associations were observed between cadmium and POPs, on one hand, and bone metabolism markers and BMD, on the other.

25-hydroxyvitamin D accumulation during summer in elderly women at latitude 60 degrees N

OBJECTIVES

During half of the year, cutaneous synthesis of 25-hydroxyvitamin D (25(OH)D) is not detectable at northern latitudes, leaving the population dependent on other sources for optimal vitamin D status. During April to September, 25(OH)D status may be improved by solar exposure. In this study, we measured seasonal differences in serum 25(OH)D concentrations and identified the major predictors of summer 25(OH)D concentrations.

DESIGN

We assessed serum 25(OH)D concentrations during both winter and summer amongst 100 women, aged 61-83 years, randomly sampled from the Swedish Mammography Cohort. Participants completed two detailed questionnaires covering diet, use of dietary supplements and sun-related behaviour, the first in January through March and a second time in August through September.

RESULTS

The mean seasonal increase in serum 25(OH)D concentrations was 38% from mean 72 +/- 23 nmol L(-1) during winter to 99 +/- 29 nmol L(-1) in summer. High summer 25(OH)D concentrations were associated with higher winter concentrations, preference of staying in sun instead of shade, having a nonsensitive skin type and normal body mass index. Based on multiple linear regression modelling, preferring sun, having nonsensitive skin type and normal weight as compared with preferring shade, having sensitive skin type and being obese, was associated with a 64 nmol L(-1) higher 25(OH)D concentrations during summer.

CONCLUSIONS

Women with high winter 25(OH)D serum concentrations, with preference of staying in the sun instead of shade during summer, a skin type allowing for longer sun exposure and a normal weight had the highest summer 25(OH)D concentrations.

Creatinine versus specific gravity-adjusted urinary cadmium concentrations

The aim was to assess how urinary creatinine is affected by age, gender, body size and meat intake, and to determine to what extent such factors might affect the creatinine adjustment of urinary cadmium. The study was based on three Swedish studies: (1) 67 non-smoking women aged 20-50 years (24-h urine samples); (2) 289 men and 434 women aged 16-81 years (spot urine samples); and (3) 98 men and 105 women aged 19-72 years (spot urine samples). The effects of age, body surface area (as an indicator of muscle mass), and meat intake on urinary creatinine and cadmium were analysed using multiple regression analyses. Gender- and age-related variations in urinary creatinine and cadmium adjusted for creatinine or specific gravity were compared by ANOVA or ANCOVA. In the multiple regression analyses, body surface area, gender, age and meat intake were the major determinants of urinary creatinine. Urinary cadmium adjusted for creatinine and specific gravity were also dependent on body size, gender and age. Urinary cadmium adjusted for creatinine was 15-92% higher in women or older individuals than in men or younger individuals. Women or older individuals had -3 to 79% higher urinary cadmium adjusted for specific gravity than men or younger individuals had, and such a difference between gender or age group was less obvious in specific gravity adjustment than in creatinine adjustment. Thus, urinary cadmium adjusted for creatinine is more affected by age, gender, body size and meat intake than is specific gravity adjustment. When comparing individuals or populations with large differences in muscle mass or meat intake, such effects can be especially important. In such studies, specific gravity adjustment seems to be more appropriate.

BALF-derived fibroblasts differ from biopsy-derived fibroblasts in systemic sclerosis

Growth of fibroblasts from bronchoalveolar lavage fluid (BALF) in patients with systemic sclerosis (SSc) has previously been described. The purpose of the present study was to characterise fibroblasts from BALF and bronchial biopsies from SSc patients with alveolitis and from controls, to analyse fibroblast proliferation, migration, stress fibres and proteoglycan production. BALF and bronchial biopsies were collected from 10 patients with SSc and alveolitis and from 15 controls. Outgrowth of fibroblasts was observed from the BALF of four patients, particularly in those with a markedly increased percentage of eosinophils in BALF, but not in any member of the control group. Increased levels of granulocyte-macrophage colony-stimulating factor, correlating with the percentage of eosinophils in BALF, were found in patients when compared with controls. Fibroblasts from BALF showed an elongated, mobile phenotype and increased proteoglycan production compared to the corresponding biopsy fibroblasts. In conclusion, outgrowth of fibroblasts with an altered phenotype is reported from bronchoalveolar lavage fluid in systemic sclerosis patients with alveolitis and an increased percentage of eosinophils in the bronchoalveolar lavage fluid. These findings indicate a possible role for eosinophil-fibroblast interaction in pulmonary fibrosis in systemic sclerosis.

Screening for pulmonary hypertension in systemic sclerosis: the longitudinal development of tricuspid gradient in 227 consecutive patients, 1992-2001

OBJECTIVE

To evaluate the longitudinal development of the tricuspid gradient (TG) for screening for pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc).

METHODS

Doppler echocardiography was performed 506 times in order to estimate TG in 227 consecutive patients with SSc. The value of biochemical markers for predicting TG levels and development was assessed through analyses of pro-brain natriuretic peptide (proBNP), calcitonin-gene related peptide, thrombomodulin and von Willebrand factor in 76 patients with a borderline increase in TG, defined as TG 24-38 mmHg, and for the purpose of comparison also in 10 patients with a normal TG (< 23 mmHg) and in 10 patients with increased TG (TG > 38 mmHg).

RESULTS

TG > 23 mmHg was found in 102 patients (44.9%) at the first assessment point and in 139 patients (61.2%) respectively, cumulatively at follow-up. TG values > 33 mmHg were measured in 24 patients (10.6%) initially and in 38 patients (16.7%) cumulatively in a subsequent assessment. Age and the presence of interstitial lung disease (ILD) were associated with more frequent occurrence of TG > 23 and > 33 mmHg initially and at follow-up, but were not associated with progression rate. The change in TG (mean +/- S.D.) was 1.34 +/- 4.55 mmHg/yr. ProBNP correlated to TG.

CONCLUSION

An increased TG, indicating possible PAH, is common and progressive in SSc. Age and ILD increase the risk of increased TG. Patients with or without ILD have similar progression of TG. ProBNP has potential as an adjunct to TG in selecting patients eligible for invasive treatment.

Longitudinal development of skin involvement and reliability of high frequency ultrasound in systemic sclerosis

BACKGROUND

Measurement of skin involvement is essential for diagnosis and prognosis in systemic sclerosis. Assessment by palpation skin score is the current method.

OBJECTIVE

To explore high frequency ultrasound as an objective method to improve skin characterisation by combining measurements of skin thickness and echogenicity.

METHODS

Skin thickness and echogenicity were measured at the proximal phalanx of the second digit, the back of the hand, the forearm, and the lower leg and, in order to separate limited (lSSc) from diffuse SSc (dSSc), at the chest in 16 patients with early disease and in 16 controls. Measurements were repeated in each patient three or four times with an interval of 1-2 years. Ultrasound measurements of skin thickness were compared with the palpation skin score.

RESULTS

Compared with controls, the skin was thickened on the phalanx, hand, forearm, and chest of patients with dSSc, but not patients with lSSc, at the 1 year examination. In dSSc the degree of thickening tended to diminish with time, and at 4 years, thickness was significantly decreased on the forearm and chest compared with the 1 year measurements. Low reflectancy was most pronounced at the 1 year evaluation on the forearm, hand, and phalanx in dSSc, and on the phalanx in lSSc.

CONCLUSION

Separate measurements of skin thickness and echogenicity by high frequency ultrasound add a new dimension to the assessment of skin involvement in SSc, and this seems to be an objective non-invasive tool for use in the study of disease development and in clinical trials.

Daily activities and hand function in women with scleroderma

OBJECTIVE

To give a detailed description of hand function and the ability to perform daily activities among patients with systemic sclerosis.

METHODS

Thirty patients with scleroderma answered a self-administered activities of daily living (ADL) questionnaire. Hand function was estimated with respect to hand mobility, dexterity, and grip force. Perceived symptoms were reported on a visual analogue scale (VAS), and skin thickness was assessed by means of the modified Rodnan skin score.

RESULTS

Finger flexion and extension were the most impaired aspects of hand mobility. Dexterity was on average reduced to 68-80%, and grip force to 46-65% compared with values for healthy persons. The predominant self-perceived problem was Raynaud's phenomenon, whereas pitting scars/ulcers were perceived as the least problem. Activities building on hand and arm function were harder to perform than activities depending on lower limb function. Raynaud's phenomenon, stiffness, grip force, and dexterity were factors with the strongest associations with ADL difficulties. Assistive devices and alternative working methods improved ADL ability.

CONCLUSION

Impaired hand function was related to ADL difficulties and the use of assistive devices improved ADL. This emphasizes the importance of treatments that improve hand function and of testing ergonomic tools.

Daily activities and hand function in women with scleroderma

OBJECTIVE

To give a detailed description of hand function and the ability to perform daily activities among patients with systemic sclerosis.

METHODS

Thirty patients with scleroderma answered a self-administered activities of daily living (ADL) questionnaire. Hand function was estimated with respect to hand mobility, dexterity, and grip force. Perceived symptoms were reported on a visual analogue scale (VAS), and skin thickness was assessed by means of the modified Rodnan skin score.

RESULTS

Finger flexion and extension were the most impaired aspects of hand mobility. Dexterity was on average reduced to 68-80%, and grip force to 46-65% compared with values for healthy persons. The predominant self-perceived problem was Raynaud's phenomenon, whereas pitting scars/ulcers were perceived as the least problem. Activities building on hand and arm function were harder to perform than activities depending on lower limb function. Raynaud's phenomenon, stiffness, grip force, and dexterity were factors with the strongest associations with ADL difficulties. Assistive devices and alternative working methods improved ADL ability.

CONCLUSION

Impaired hand function was related to ADL difficulties and the use of assistive devices improved ADL. This emphasizes the importance of treatments that improve hand function and of testing ergonomic tools.

Assessment of skin, joint, tendon and muscle involvement

This report makes recommendations for standardized techniques of data gathering and collection regarding: 1) skin involvement 2) joint and tendon involvement, and 3) involvement of the skeletal muscles. The recommendations in this report derive from a critical review of the available literature and group discussion. Committee recommendations are considered appropriate for descriptive clinical investigation, translational studies and as standards for clinical practice. Skin involvement should be assessed using the modified Rodnan skin score. Joint involvement, when symmetric synovitis is present, could be best assessed by the DAS-28 as is utilized in rheumatoid arthritis. Clinical assessment should include a routinized evaluation for the presence and number of palpable tendon friction rubs. Muscle involvement should be screened for by performance of the serum creatine phosphokinase assay and assessment of proximal weakness. More specific testing including EMG, magnetic resonance imaging and muscle biopsy should be employed in those patients with clinically significant myopathy only.

The association of antinuclear antibodies with organ involvement and survival in systemic sclerosis

OBJECTIVES

To study the frequency and specificity of antinuclear antibodies (ANA) and their association with internal organ involvement and survival in systemic sclerosis (SSc).

METHODS

Sera from 276 SSc patients were analysed by an indirect immunofluorescence (IIF) technique with HEp-2 cells as a substrate to categorize centromeric (ACA), nucleolar, speckled and homogeneous nuclear IIF patterns. Specific ANA were determined as follows: anti-DNA topoisomerase I (anti-topo I) by double immunodiffusion, anti-U1 RNP by passive haemagglutination, anti-RNA polymerase I, II and III (anti-RNAP) and anti-histone (AHA) antibodies by enzyme immunoassays. During the follow-up of 7.0+/-4.5 (mean+/-S.D.) yr the occurrence of clinical manifestations and internal organ involvement was registered.

RESULTS

ANA were present in 84% of the patients. The most common patterns of the IIF were speckled (41%), homogeneous (25%), nucleolar (24%) and centromeric (18%). A nucleolar pattern was associated with pulmonary fibrosis (P < 0.01) and cardiomegaly (P < 0.05). ACA were related to organic vasculopathy (P < 0.05) and renal involvement (P < 0.01), but not to pulmonary fibrosis (P < 0.01). Anti-topo I were present in 9.4%, anti-U1 RNP in 21%, anti-RNAP in 22% and AHA in 16% of the patients. Pulmonary involvement was more common in patients with anti-topo I (P < 0.05), whereas AHA-positive patients were characterized by cardiac (P < 0.05), pulmonary (P < 0.05) and renal (P < 0.05) involvement. A nucleolar IIF pattern and AHA were both associated with a decreased survival [relative risk of death 1.71 (P < 0.05) and 2.36 (P < 0.01), respectively].

CONCLUSIONS

AHA and a nucleolar HEp-2 cell pattern may indicate critical organ involvement and predict a reduced survival in SSc patients.

The association between changes in skin echogenicity and the fibroblast production of biglycan and versican in systemic sclerosis

OBJECTIVE

To investigate a possible association between the longitudinal changes in skin involvement and the fibroblast production of proteoglycans in vitro, among patients with early and untreated systemic sclerosis (SSc).

METHODS

In 11 patients, 6 with diffuse cutaneous systemic sclerosis (dSSc) and 5 with limited cutaneous systemic sclerosis (ISSc), and in 6 controls skin thickness and skin echogenicity of the forearm was measured by high frequency (20 MHz) ultrasound. A skin biopsy was taken from the area of the ultrasound measurements, and from cultivated fibroblasts the production of the proteoglycans versican, perlecan, biglycan and decorin were measured. To investigate longitudinal changes in skin involvement, the ultrasound examination was repeated after 1-3 years.

RESULTS

Compared to controls, SSc patients had increased skin thickness at the first evaluation. Patients with dSSc had lower skin echogenicity than both patients with lSSc and the controls. Patients with greater changes in skin thickness and skin echogenicity produced more versican, whereas the production of biglycan and decorin was higher only in patients with greater changes in skin echogenicity. There was a negative correlation between fibroblast production of biglycan and disease duration.

CONCLUSION

High fibroblast synthesis of the proteoglycans versican and biglycan is associated with changes in skin echogenicity and may predict more progressive skin sclerosis in SSc.

Characterization of specific IgE response in vitro against protein and drug allergens using atopic and normal donors

BACKGROUND

As the incidence of allergy to different compounds increases in society, the need to understand and characterize specific IgE responses becomes obvious. Different cell culture systems have been evaluated for their ability to support such IgE secretion.

METHODS

One system employed human peripheral lymphocytes (PBL) from normal donors stimulated with anti-CD3 activated T cells with or without the presence of allergens like benzylpenicillin (BP) and Phlenum pratense (PP). Secretion of IgE was analyzed in ELISA and compared to the IgG response to the nonallergenic antigen tetanus toxoid (TT). Another system employed stimulation of T and B cells with a heterotope, consisting of a T helper cell epitope derived from TT, and a B cell allergen epitope derived from BP. The specific IgE secretion was compared, using lymphocytes from normal as well as BP-allergic donors.

RESULTS

Anti-CD3 stimulated T cells supported BP-specific IgE secretion in six of 11 normal donors. This response was inhibited in four donors and enhanced in two donors by the addition of the BP-allergen to the culture. In contrast, addition of the protein allergen (PP) or antigen (TT) to the same culture system inhibited both IgE and IgG synthesis in all experiments. Cells from the majority (10/16) of the BP-allergic donors failed to produce BP-specific IgE in vitro, when cultured in the presence of allergen.

CONCLUSIONS

An allergen specific immune response is readily generated in vitro. The differential response against benzylpenicillin between different donor categories most probably reflects the level of pre-exposure to this allergen in vivo.

Correlation between plasma concentrations of calcitonin gene related peptide and pulmonary pressure in patients with systemic sclerosis

OBJECTIVE

To examine plasma levels of calcitonin gene related peptide (p-CGRP) in patients with systemic sclerosis (SSc) and pulmonary hypertension (PH).

MATERIAL AND METHODS

Twenty nine patients with SSc, 10 with diffuse form, 18 with limited form and one with overlapping systemic lupus erythematosus were examined. Twelve patients displayed normal systolic pulmonary artery pressure (PAPsyst) < or =30 mm Hg and 17 increased PAPsyst >30 mm Hg. Eight patients had isolated PH without interstitial lung disease (ILD) and nine had PH and ILD (secondary PH). PAPsyst was measured non-invasively by Doppler cardiography. CGRP was determined by radioimmunoassay.

RESULTS

Patients with PH had higher p-CGRP than patients with normal pressure. A positive relation was found between p-CGRP and PAPsyst and between p-CGRP and erythrocyte sedimentation rate (ESR), particularly in patients with isolated PH.

CONCLUSION

In patients with SSc p-CGRP correlates with pulmonary pressure and with ESR. Whether CGRP reflects disease activity or is released secondary to pulmonary vasoconstriction needs to be investigated further.

Metals and women's health

There is a lack of information concerning whether environmental-related health effects are more or less prevalent or manifested differently in women compared to men. Previously, most research in the area of toxicology and environmental and occupational health involved male subjects. The present work aims at reviewing exposure and health effects of cadmium, nickel, lead, mercury, and arsenic manifested differently in women than in men. The gender difference in exposure to nickel results in a much higher prevalence of nickel allergy and hand eczema in women than in men. The internal cadmium dose is generally higher in women than in men, due to a higher gastro-intestinal absorption at low iron stores. This was probably one major reason why Itai-itai disease was mainly a woman's disease. Yet, data are sparse regarding the risk for women relative to men to develop cadmium-induced kidney damage in populations exposed to low levels of cadmium. Lead is accumulated mainly in bone and increased endogenous lead exposure has been demonstrated in women during periods of increased bone turnover, e.g., menopause. Both lead and mercury exposure in pregnant women has to be kept low in order to prevent neurodevelopment effects in the developing fetus and child. Limited data indicate that women are more affected than men following exposure to methylmercury at adult age, while males seem to be more sensitive to exposure during early development. Regarding arsenic, some data indicate gender differences in the biotransformation by methylation, possibly also in susceptibility to certain arsenic-related cancers. Obviously, gender-related differences in exposure and health effects caused by metals are highly neglected research areas, which need considerable focus in the future.

Disease severity of 100 patients with systemic sclerosis over a period of 14 years: using a modified Medsger scale

OBJECTIVE

To assess organ involvement according to a modified Medsger severity scale and its relation to outcome and prognosis in patients with systemic sclerosis.

METHODS

One hundred consecutive patients observed in Lund with systemic sclerosis were followed up for a period of 14 years. The mean follow up time was 7.7 years. Initial assessment and an annual evaluation was performed for each patient, with a mean visit frequency of 5.6 per patient.

RESULTS

Age at referral, high total skin score, truncal skin involvement, low vital capacity, low static lung compliance, low Cr-EDTA clearance, and ECG abnormalities at the initial assessment predict poor outcome. A severity scoring system for five organ systems indicates a slow progression of organ dysfunction after recruitment into the study. The female: male ratio was 2:1, the mean age at onset of symptoms was 42.3 (range 3-82), and the mean age at recruitment was 47.2 years (range 17-82). Thirty patients died during the follow up period at the mean age of 61.3 years (range 33-85). The causes of death were directly related to systemic sclerosis in at least 10 patients, infections in six, cancers in nine, and other causes in four patients. The standardised mortality ratio was 3.5 and 3.7 for men and women, respectively.

CONCLUSION

A high severity score for function of vital organs was shown to predict shortened survival. In this study a severity score based on simple clinical assessment variables was able to predict poor outcome from extensive skin changes, ECG changes, and compromised lung and renal function. Organ dysfunction mainly became manifest during the first five years of the disease, whereafter organ function remained largely stable.

Von Willebrand factor propeptide as a marker of disease activity in systemic sclerosis (scleroderma)

In 44 consecutive patients with systemic sclerosis (SSc), plasma concentrations of von Willebrand factor (vWf) were higher than those of the vWf propeptide, but the propeptide showed less variability within patient subgroups. Higher values of the propeptide were observed in patients with early pulmonary involvement. A closer correlation of the propeptide than of vWf to biochemical markers of activity was also evident. Our results suggest that the propeptide, despite a shorter circulating half-time and lower plasma concentrations than vWf, is more useful in the assessment of disease activity in SSc.

Longitudinal study of methylmercury and inorganic mercury in blood and urine of pregnant and lactating women, as well as in umbilical cord blood

We have investigated exposure to methylmercury (MeHg) and mercury vapor (Hg0) in pregnant women and their newborns in Stockholm. The women were followed for 15 months post delivery. MeHg, inorganic Hg (I-Hg), and total Hg (T-Hg) in maternal and cord blood were determined by automated alkaline solubilization/reduction and cold vapor atomic fluorescence spectrometry. T-Hg in urine was determined by inductively coupled plasma mass spectrometry. About 72% of the Hg in blood (n = 148) in early pregnancy was MeHg (median 0.94 microg/L, maximum 6.8 microg/L). Blood MeHg decreased during pregnancy, partly due to decreased intake of fish in accordance with recommendations to not eat certain predatory fish during pregnancy. Cord blood MeHg (median 1.4 microg/L, maximum 4.8 microg/L) was almost twice that in maternal blood in late pregnancy and was probably influenced by maternal MeHg exposure earlier and before pregnancy. Blood I-Hg (median 0.37 microg/L, maximum 4.2 microg/L) and urine T-Hg (median 1.6 microg/L, maximum 12 microg/L) in early pregnancy were highly correlated, and both were associated with the number of amalgam fillings. The concentrations decreased during lactation, probably due to excretion in milk. Cord blood I-Hg was correlated with that in maternal blood. The results show the importance of speciation of Hg in blood for evaluation of exposure and health risks.

Circulating collagen metabolites in systemic sclerosis. Differences between limited and diffuse form and relationship with pulmonary involvement

OBJECTIVE

To study collagen metabolites in systemic sclerosis (SSc) and their relationship with clinical manifestations of the disease.

METHODS

Forty-eight SSc patients, 13 with a diffuse form (dcSSc), 23 with a limited form (lcSSc) and 12 with suspected SSc not fulfilling the ACR criteria, and 31 healthy controls were examined. Serum concentrations of aminoterminal type III procollagen peptide (PIIINP), aminoterminal and carboxyterminal type I procollagen peptides (PINP and PICP) and cross-linked carboxyterminal telopeptide of collagen I (ICTP) were determined by radioimmunoassay.

RESULTS

Increased serum concentrations of ICTP were found in SSc patients compared with controls. Distinctly higher levels of ICTP were observed in dcSSc than in lcSSc. High serum ICTP was correlated with skin score and acute phase reactants, and with reduced pulmonary function. Serum PIIINP concentration was elevated in both lcSSc and dcSSc.

CONCLUSION

Augmented collagen catabolism accompanies the increased collagen synthesis in SSc. Serum ICTP concentration is a marker of this feature and also reflects clinical severity.

Rapid polarization of Th2 cells during induction of antigen-specific IgE antibodies in vitro

BACKGROUND

Type 2 T-helper cells (Th2) are involved in the regulation of the humoral immune response against antigens and allergens and directly affect which isotype will be produced. The mechanism that regulates antigen-specific IgE secretion and immune deviation is still not known.

OBJECTIVES

To delineate mechanisms behind antigen-specific IgE secretion we have used in vitro immunization and focused on T-cell phenotype and the activation status of the transcription factor NFkappaB.

METHODS

Peripheral blood lymphocytes (PBMC) from seronegative donors were immunized in vitro with a peptide consisting of both a T-cell and a B-cell epitope.

RESULTS

Antigen-specific IgE antibodies could be detected after a primary immunization, during which T-helper cells secreted type 2 cytokines. Specific IgE was also detected in the secondary immunization, but due to a rapid polarization from Th2 to Th1 phenotype, exogenous IL-4 was required for the specific IgE secretion. Analysis of NFkappaB activation in B and T cells during primary and secondary immunization showed that NFkappaB could be detected in both B and T cells during primary immunization, but was dependent on exogenous IL-4 in the secondary immunization.

CONCLUSION

This is the first evidence of antigen-specific IgE induction in vitro using naive B cells, demonstrating the involvement of T-helper cell phenotype and NFkappaB and demonstrates the usefulness of in vitro cultures to study the effect of antigens on human immunocytes.

Phlebotomy increases cadmium uptake in hemochromatosis

The intestinal absorption of the nephrotoxic environmental pollutant cadmium increases markedly when iron stores are depleted. This may be mediated by an up regulation of the recently identified mucosal transporter DMT1 (Nramp2 or DCT1) for divalent cations. We tested whether the highly increased iron absorption in hereditary hemochromatosis (HH) was accompanied by an enhanced absorption of cadmium and lead. Cadmium and lead in blood and iron status markers were determined in 21 nonsmoking subjects with HH genetically tested for the HFE mutations and in 21 nonsmoking controls matched for age and sex. In subjects with HH on maintenance phlebotomy treatment, blood concentrations of cadmium, but not lead, were significantly higher than in paired controls. There was a strong age-independent positive association between blood cadmium and the number of years of phlebotomy treatment. Blood lead showed a similar but less pronounced consequence of treatment. All HH subjects with lower blood cadmium than the corresponding controls had either no mutation in the HFE gene, were not phlebotomized, or were phlebotomized for only a limited time. Our findings indicate that the treatment rather than the disease increased the cadmium uptake in homozygous HH. Further studies are needed to confirm whether the disease decreased cadmium absorption and whether the absorption was dependent on the genotype.

Metal-bone interactions

Recent studies indicate that lead and cadmium may exert both direct and indirect actions on bone turnover, indirectly via kidney dysfunction, and directly on osteoblast and osteoclast function. Increased blood lead concentrations, most likely as a result of an increased bone turnover, have been detected in pregnant, lactating, and menopausal women. Lead exposure has also been negatively associated with children's growth in stature. Both lead and cadmium are nephrotoxic and can disturb vitamin D metabolism. Cadmium has been shown to induce kidney damage and osteoporosis/osteomalacia at long-term high-level exposure. A negative association between cadmium dose and bone mass has recently been detected in both occupationally and environmentally exposed people at relatively low cadmium exposure.

Toxic and essential elements in placentas of Swedish women

OBJECTIVES

To evaluate interactions between toxic and essential elements in the mother-fetus relationship and possible predictors of trace element concentrations in placenta and cord blood.

DESIGN AND METHODS

A group of 106 Swedish women was investigated for concentrations of cadmium, lead, and several essential elements in placenta as well as cadmium, lead, zinc, and selenium in venous blood collected at gestational week (gw) 36 and umbilical cord blood. Relations between these elements and maternal and child's characteristics were examined.

RESULTS

The concentrations of cadmium in placenta ranged from 10 to 170 nmol/kg, with the median value (Md) being 46 nmol/kg. Cord blood cadmium (Md of 0.19 nmol/L) was only about 10% of that in maternal blood. Smokers had significantly higher cadmium concentrations in blood (p < 0.001) and placenta (p = 0.001) than non-smokers. The median placental concentration of lead was 26 nmol/kg (range 0-630 nmol/kg). The lead levels in cord blood (Md of 54 nmol/L) were almost the same as in maternal blood. Statistically significant negative associations were found between cord blood lead, on one hand, and child's weight, length, and head circumference, on the other. The placental levels (medians and ranges) of the essential elements (micromol/kg) were 160 (120-280) for zinc, 2.4 (2.0-3.3) for selenium, 15 (10-20) for copper, 0.084 (0.02-0.32) for cobalt, 0.055 (0.03-0.12) for molybdenum, and 1.2 (0. 65-5.1) for manganese, respectively. Several of the essential elements in placenta correlated significantly with each other. Multiparous mothers had significantly lower concentrations of zinc (p = 0.002) and selenium (p = 0.049) in serum as well as zinc (p = 0. 001) and calcium (p = 0.004) in placenta than nulliparous ones. Also, cord blood zinc decreased with parity.

CONCLUSIONS

The results showed that lead, but not cadmium crossed easily the placental barrier. There were no negative effects of cadmium on the zinc status. Cord blood lead, on the other hand, was a negative predictor of child's birth weight, length and head circumference, indicating that lead might have negative influence on growth in children even at very low exposure levels. There was a depletion of maternal stores of essential elements with increasing parity.

Interferon-alpha and ribavirin treatment of hepatitis C in children with malignancy in remission

Twenty-eight cases of hepatitis C virus (HCV) infection were identified in children in a pediatric oncology ward during 2 nosocomial outbreaks. HCV infection spontaneously cleared in 6 patients (21%). Eleven patients with persistent HCV viremia who had malignant diseases in remission after treatment were given a 48-week course of combined therapy with interferon-alpha (5x106 U 3 times weekly) and oral ribavirin (15 mg/kg/d). Seven (64%) of the 11 patients had sustained virological responses 6 and 12 months after cessation of therapy. Side effects were common but generally were mild or moderate.

A disease severity scale for systemic sclerosis: development and testing

OBJECTIVE

To develop and test a severity scale for individual organ involvements in systemic sclerosis (SSc, scleroderma).

METHODS

An international study group completed the following tasks: (1) developed a glossary of terms including all pertinent variables for 9 potentially affected organ systems; (2) collected prospective data to determine the feasibility and practicality of each proposed variable; (3) revised the initial list of variables; (4) determined the association of each variable with mortality (a proxy for morbidity) using 579 patients in an existing comprehensive longitudinal scleroderma databank; (5) developed a severity grading scale for each organ system by discussion and consensus; and (6) externally validated the scale using an independent group of 680 patients from the same databank.

RESULTS

Nine organ-specific severity scales were developed from 0 (no documented involvement) to 4 (endstage disease). The data required for scale completion are relatively easy and practical for all physicians to obtain.

CONCLUSION

This preliminary severity scale will be useful for assessing disease severity status in individual patients both at one point in time and longitudinally. The severity scale will assist in the design and conduct of clinical trials and the comparison of study populations with one another. The scale will serve as a framework for developing a scleroderma disease activity index.

Evaluation of kits for measurement of the soluble transferrin receptor

Three commercially available kits for determination of the soluble serum transferrin receptor (sTfR), R&D Systems, UK, Ramco Laboratories, USA and Orion, Finland were compared with respect to practicability, comparability and ability to discriminate between iron deficient and non-iron deficient subjects. Serum samples representing different concentrations of sTfR were tested. The three kits involved virtually the same laboratory procedures except for a predilution step for Ramco. Both the absolute amounts and the units (mg/L and nmol/L) differed among the kits, emphasizing the need for internationally accepted reference material and comparable units. The correlation coefficients were 0.974 (Ramco and R&D), 0.769 (R&D and Orion) and 0.759 (Ramco and Orion), indicating a lower comparability for Orion compared to the other two kits. The differences between the kits may be attributed to uncertainties in the reference intervals and to variations in kit format. This may have implications for studies of the usefulness of sTfR as a marker of iron deficiency.

Capillary density in patients with systemic sclerosis, as determined by microscopy counts and compared with computer-based analysis

OBJECTIVE

To develop a method enabling capillary density to be determined rapidly and accurately in patients with systemic sclerosis.

METHOD

Capillary density was determined in 11 controls and 22 patients: 5 with diffuse cutaneous systemic sclerosis (dSSc), 12 with limited cutaneous systemic sclerosis (lSSc), two with suspected systemic sclerosis (suspSSc), 2 with sclerodermatomyositis, and one with undifferentiated connective tissue disease. Using a microscope equipped with a graticule, nailfold capillaries were counted within a 3 mm length of the nailfold; these counts were made by 4 different observers. The results were compared with the corresponding values obtained by the computerbased analysis of photographs.

RESULTS

The median capillary density according to the direct counts was 8.0 loops/mm (6.7-10.0) in the controls, 6.0 loops/mm (range 4.8-8.8) in the dSSc subgroup, 5.6 loops/mm (4.2-6.5) in the lSSc subgroup, and 7.2 loops/mm (6.2-8.2) in the suspSSc subgroup. In the series as a whole, there was no significant difference between the median values for the left hands and those for the right hands, nor between the median value for all digit IVs and the median value for all four digits analysed (II, III, IV, and V). Interobserver variation was small between the 4 different observers. Direct microscopy counts were slightly higher than the corresponding values obtained by computer-based analysis.

CONCLUSION

Direct microscopy counting is a rapid, simple, and reliable means of determining capillary density for screening purposes.

Serum transferrin receptor: a specific marker of iron deficiency in pregnancy

BACKGROUND

Current markers of iron deficiency tend to be less reliable in pregnancy.

OBJECTIVE

Our aim was to study the usefulness of soluble serum transferrin receptor (sTfR) as a marker for iron deficiency during early and late gestation and to define iron status in 254 pregnant Swedish women.

DESIGN

We performed a cross-sectional and longitudinal evaluation of sTfR in comparison with concentrations of serum ferritin and hemoglobin in blood collected around gestational weeks 11 and 36.

RESULTS

The specificity of sTfR was 100%. The sensitivity in relation to both anemia and depleted iron stores was approximately 70%, but this figure is less reliable because of few samples. sTfR in early pregnancy was low: 11% of women had a value below the reference interval. sTfR increased significantly from early to late pregnancy even in the group of women with persisting iron stores. In late pregnancy, 14% of women developed tissue iron deficiency and 5% had iron deficiency according to a combination of all 3 markers.

CONCLUSIONS

sTfR seems to be a specific and sensitive marker of iron deficiency in pregnancy and may have advantages over serum ferritin and hemoglobin. The low sTfR concentration in early gestation seems to be caused by reduced erythropoiesis, whereas the increase from early to late pregnancy reflects increased erythropoiesis, and in case of iron deficiency, also tissue iron deficiency. Further studies are needed to verify whether decreased erythropoiesis reduces the possibility of detecting iron deficiency during early gestation by sTfR.

Mortality and causes of death in a Swedish series of systemic sclerosis patients

OBJECTIVES

To analyse survival rates and the causes of death in a systemic sclerosis (SSc) population, and to evaluate the occurrence of fatal malignant neoplasms and their possible association with oral cyclophosphamide (CYC) treatment.

METHODS

Survival was calculated for 249 SSc patients followed up for up to 13 years. Mean (SD) follow up was 5.8 (4.2) years. The 49 decreased patients were subdivided according to causes of death and its relation to SSc. Fatal malignancies in CYC treated patients were compared with those occurring in non-CYC treated patients.

RESULTS

The overall 5 and 10 year survival rates were 86% and 69% respectively. There was a 4.6-fold increased risk of death, as compared with the general population. Prognosis was worse in the diffuse cutaneous involvement (dSSc) and male subgroups than in the limited cutaneous involvement (1SSc) and female subgroups. Of the 49 deaths, 24 were attributable to pulmonary complications such as pulmonary fibrosis, pulmonary hypertension, pneumonia or pulmonary malignancy. Treatment with oral CYC did not increase the risk of dying of cancer.

CONCLUSIONS

Mortality is increased both in the SSc population as a whole and in its different subsets (dSSc and 1SSc). Prognosis is worst among male patients with dSSc. However, the 5 year survival rate was better than those reported from earlier studies. Most patients die of cardiopulmonary disease. Five of seven fatal lung cancers were adenocarcinomas, possibly caused by chronic inflammatory disease of the lung. In this study, CYC treatment was not associated with an increased incidence of fatal malignant neoplasms.

Cyclophosphamide therapy for scleroderma

Pulmonary manifestations are the most common cause of death in patients with scleroderma. Consequently, the importance of treatment of both interstital lung disease and pulmonary hypertension has become increasingly evident. Until a placebo-controlled study of any drug has shown its beneficial effect on pulmonary dysfunction, cyclophosphamide may be useful for the treatment of scleroderma lung disease.

Validation with biological markers for food intake of a dietary assessment method used by Swedish women with three different dietary preferences

OBJECTIVES

To validate a dietary assessment method, a 4-day food record together with a duplicate portion technique, with biological markers for food intake.

DESIGN

Four days of duplicate portions were collected in parallel with food recording. A 24-h urine sample and the faeces corresponding to the food intake (using a coloured marker) were collected. Completeness of urine and faeces collections was assessed using para-aminobenzoic acid (PABA) in urine and cadmium in faeces, respectively. Biomarkers of food intake (energy, protein, fibre, sodium, potassium, calcium) were measured in urine and faeces.

SETTING

Swedish west coast.

SUBJECTS

Non-smoking Swedish women, 20-50 years of age, consuming a mixed diet (n = 34), a mixed diet rich in shellfish (n = 17) or a vegetarian/high-fibre diet (n = 23).

RESULTS

The average ratio (food intake according to the dietary assessment methods/ biological marker) for protein, sodium, potassium and calcium was 0.86. This indicates an underestimation of the food intake by approximately 15%. The ratio of stated fibre intake to biological marker was 1.20 for the mixed diet and the vegetarian diet group, indicating an overestimation by approximately 20%.

CONCLUSIONS

The underestimation of the intake of protein, sodium, potassium and calcium by all three groups and the overestimation of the fibre intake by two groups indicate that underreporting is selective to certain nutrients and foods and to various groups of people. The two dependent dietary assessment methods were equally good in measuring protein intake, which indicates that the women recorded what they actually duplicated.

Tissue concentrations of gastrointestinal regulatory peptides in the duodenal mucosa in systemic sclerosis

OBJECTIVE

Esophageal hypomotility and abnormalities of intestinal function are important manifestations in systemic sclerosis (SSc), but their pathogenesis is not well understood. Since there is evidence that plasma concentrations of certain gastrointestinal regulatory peptides are increased in SSc, we were interested in examining the peptide concentrations and localization in biopsy specimens from the intestinal mucosa in SSc patients. We studied 12 patients with gastrointestinal disease.

METHODS

Levels of corticotrophin-releasing hormone (CRH), motilin, neuropeptide Y (NPY) and peptide YY (PYY) were determined by radioimmunoassay and high-performance liquid chromatography (HPLC), and the occurrence of motilin, PYY, somatostatin, and NPY were studied with immunohistochemistry.

RESULTS

Except for the concentrations of CRH, which were increased 2-fold, the tissue concentration of motilin, NPY and PYY were decreased by approximately 50% among patients with esophageal and intestinal dysfunction (group B) compared to patients with impaired esophageal motility alone (group A). In addition, HPLC-characterization of motilin, NPY, and PYY showed a different pattern of fragments among patients in groups A and B. In all patients duodenal motilin, PYY, and somatostatin were localized in the endocrine cells. The distribution and frequency of the cells did not differ among the patients. NPY was localized to neuronal elements; there was no overt difference among the patients with respect to the frequency of NPY-containing nerves.

CONCLUSION

This study shows that patients with widespread gastrointestinal disease have lower tissue concentrations of regulatory peptides compared to patients with less widespread disease.

Assessment of functional ability in patients with scleroderma: a proposed new disability assessment instrument

OBJECTIVE

To develop a simple assessment of functional ability in patients with scleroderma and to examine its reliability both as a patient self-administered instrument and when administered by a trained observer.

METHODS

An 11 item, 4 grade, functional assessment questionnaire was developed after extensive consultation with patients, physiotherapists (PT), and occupational therapists (OT) with the aim of including all functional areas of relevance. The instrument was self-administered by patients after an interval of 7 days. In the interval, the patients were assessed using the same instrument by direct observation from both a PT and an OT. Forty-seven patients with scleroderma, of varying severity, were recruited from 2 centers. Results were similar for both centers and data were pooled for analysis.

RESULTS

Agreement between the patients' first and 2nd assessment was good for all questions (estimated kappas 0.69 to 0.94) with no evidence of an order effect. Agreement was also good between therapists (estimated kappas 0.47 to 0.81). There was poor agreement between patients and therapists, with patients rating their disability substantially higher compared to the standardized therapist assessment.

CONCLUSION

This assessment schedule has high face and content validity and has excellent reliability both between trained therapists and within patients over a short time period. Its administration either as a self-report or by a therapist depends, in part, on the type of investigation undertaken.

Comparison of high frequency (20 MHz) ultrasound and palpation for the assessment of skin involvement in systemic sclerosis (scleroderma)

BACKGROUND AND OBJECTIVES

Systemic sclerosis (SSc) is a connective tissue disease characterized by microvascular changes and fibrosis of the skin and internal organs. Increased skin thickness proximal to the metacarpophalangeal joints is the single major diagnostic criterion. The aim of this study was to evaluate high frequency (20 MHz) ultrasound for the assessment of skin thickness in patients with SSc of different disease durations.

METHODS

Skin thickness was measured with high frequency (20 MHz) ultrasound equipment (Dermascan) in 41 patients with SSc (23 women and 18 men) and in 41 controls. Twenty-five patients had limited cutaneous systemic sclerosis (ISSc), 12 had diffuse cutaneous systemic sclerosis (dSSc) and 4 had suspected SSc.

RESULTS

Skin thickness of the forearm was inversely correlated to disease duration. Compared to controls, skin thickness was increased over the proximal phalanx of the right second finger and over the forearm in patients with a disease duration of 2 years or less. Assessments of skin thickness in 10 controls by 2 independent investigators showed an inter-observer variability of 1.0% for the proximal phalanx and 0.0016% for the forearm. Patients whose ultrasound showed increased skin thickness on the hand and forearm also had thickened skin by palpation.

CONCLUSION

High frequency (20MHz) ultrasound is a feasible method for measuring skin thickness in SSc, and may be useful for diagnosis, long-term follow-up, and assessment in therapeutic studies.

Altered dermatan sulfate proteoglycan synthesis in fibroblast cultures established from skin of patients with systemic sclerosis

OBJECTIVE

To study whether changes in the properties of skin from patients with systemic sclerosis (SSc) are the result of altered metabolism of dermatan sulfate proteoglycans.

METHODS

Fibroblast cultures were established from skin of healthy controls, and from affected and unaffected skin of patients with SSc. Synthesized proteoglycans were labeled with 3H glucosamine and 35S sulfate. The amount of mRNA of the different dermatan sulfate proteoglycans was determined by hybridization with the corresponding cDNA probes.

RESULTS

A 2-fold increase in secretion of total proteoglycans was found in cell cultures from affected and normal appearing skin from patients with SSc. The production of 2 different dermatan sulfate proteoglycans was increased. Aggrecan/versican increased 4-fold and decorin 2-fold in cultures of affected skin from patients with SSc. The mRNA for decorin increased 3-fold, while the mRNA level for versican increased only slightly. Similar but less marked changes were noted in cultures from normal appearing skin. In contrast, the biglycan mRNA level decreased and the product could only be found in very small amounts in SSc cultures.

CONCLUSION

This marked alteration of dermatan sulfate proteoglycan metabolism distinguishes not only affected skin but also normal appearing SSc skin from that of controls. The altered proteoglycan production may affect organization of matrix fibers and thereby the fibrotic process observed in patients with SSc.

Occurrence and distribution of peptidergic nerve fibers in skin biopsies from patients with systemic sclerosis

Systemic sclerosis is characterized by vascular dysfunction. Itch is sometimes present in early stages of the disease. This prompted us to study the innervation of the skin by immunocytochemistry. Antibodies to neuropeptide Y and vasoactive intestinal peptide were used for autonomic nerves. Sensory innervation was studied using antibodies to substance P and calcitonin gene-related peptide. Protein gene product 9.5 was used as a general neuronal marker. Skin biopsies from affected (lower arm) and non-affected (upper back) sites on 10 patients with systemic sclerosis and from corresponding sites on 10 sex- and age-matched healthy controls were studied. Regional variations were found in the occurrence of peptidergic nerve fibers. In the patients the density of nerve fibers (measured semiquantitatively) stained by the panneuronal marker was lower in affected than in unaffected skin (p < 0.05). There were no significant differences in peptidergic innervation between patients and controls. However, there was a tendency to higher density of neuropeptide Y-positive nerve fibers in the forearm skin in 6 to 10 patients, as compared to only 1 of 10 healthy controls.

Bioavailability of cadmium from shellfish and mixed diet in women

Dietary intake and uptake of cadmium (Cd) were studied in nonsmoking women, 20-50 years of age, consuming a mixed diet low in shellfish (N = 34) or with shellfish once a week or more (N = 17). Duplicate diets were collected during 4 consecutive days for the determination of Cd content. The women kept detailed dietary records, and the intake of energy and various nutrients was calculated. The shellfish diets (median 22.3 micrograms Cd/day) contained twice as much Cd as the mixed diets (median 10.5 micrograms Cd/day; p < 0.0001). Cadmium in feces corresponded to 100 and 99% of that in duplicates of shellfish diets and mixed diets, respectively, indicating a low average absorption of the dietary Cd. In spite of the differences in the daily intake of Cd, there was no statistically significant difference in the concentrations of Cd in blood (B-Cd, shellfish group 0.25 micrograms/liter, mixed diet group 0.23 micrograms/liter) or urine (U-Cd, 0.10 micrograms Cd/liter in both groups). This indicates a lower absorption of Cd in the shellfish group than in the mixed diet group or a difference in the kinetics. A higher gastrointestinal absorption of Cd in the mixed diet group could partly be explained by lower body iron stores as measured by the concentrations of serum ferritin (S-fer, median 18 micrograms/liter, compared to 31 micrograms/liter in the shellfish group). In the mixed diet group, S-fer was negatively correlated with B-Cd and the main determining for B-Cd besides U-Cd in the multiple regression analysis, indicating an increased absorption of Cd at low body iron stores. When women with S-fer exceeding 20 micrograms/liter were compared, the higher dietary intake of Cd in the shellfish group compared to the mixed diet group (24 versus 10 micrograms/day) resulted in higher B-Cd (0.26 versus 0.16 micrograms/liter), although not in proportion to the difference in Cd intake. Thus, there seems to be differences in the bioavailability and/or kinetics of dietary Cd related to the type of diet. This is, to our knowledge, the first study where the influence of various types of diets and nutritional factors on the intake and uptake of cadmium in human subjects has been studied.

Computer based quantitative analysis of capillary abnormalities in systemic sclerosis and its relation to plasma concentration of von Willebrand factor

OBJECTIVES

To evaluate an objective and quantitative method for assessment of capillary abnormalities in systemic sclerosis (SSc).

METHODS

Nailfold capillaries were investigated by capillary microscopy and photographed in 17 consecutive SSc patients (five with diffuse cutaneous systemic sclerosis (dSSc) and 12 with limited cutaneous systemic sclerosis (lSSc)) and in 17 healthy controls. Investigators having no access to clinical data made drawings from magnified projections of coded photographs and analysed them using a computer program. Capillary density (capillary loops/mm in the distal row) and median capillary loop area were calculated. Presence of functional or organic arterial changes was evaluated by measurement of finger pressure with finger cooling. Plasma concentration of von Willebrand factor (VWF) was analysed using an enzyme linked immunosorbent assay (ELISA).

RESULTS

In 16 of 17 SSc patients and 13 of 17 controls the technical quality of the photographs was sufficient for computer analysis. Capillary density was decreased in dSSc (median 6.9 loops/mm) and in lSSc (median 3.8 loops/mm) compared with healthy controls (8.9 loops/mm) and median capillary loop area was increased in dSSc (7.3 x 10(-3) mm2) and in lSSc (8.5 x 10(-3) mm2) compared with healthy controls (5.0 x 10(-3) mm2). An inverse relation was found between capillary density and median capillary loop area in SSc patients. Plasma VWF was increased in patients (median 401 IE/l in dSSc and 409 IE/l in lSSc) compared with controls matched for age and sex (median 276 IE/l). Computer based analysis showed capillary density below the control range and median capillary loop area above the control range in 14 of 16 SSc patients. Measurement of finger pressure with finger cooling showed organic vascular changes in nine of 13 SSc patients.

CONCLUSION

Computer based quantitative analysis has low interobserver variability and is a quantitative and sensitive method of assessing capillary abnormalities in SSc.

Esophageal scintigraphy of systemic sclerosis

Esophageal involvement is common in systemic sclerosis, and esophageal scintigraphy can be used to detect and follow esophageal dysfunction. This study assesses the value of visual and quantitative analysis of esophageal scintigraphy performed as a multiple swallow test in normals and patients with systemic sclerosis.

METHODS

Forty patients with systemic sclerosis and 40 sex- and age-matched healthy subjects (controls) were studied. A multiple swallow technique was used and both quantitative and qualitative analyses were performed. Visual analysis of condensed images was performed independently by two physicians. Each swallow was assigned a score on a scale from 1 to 4. In the quantitative analysis, time-activity curves based on the mean condensed images were used to calculate the following 3 parameters: residual activity 12 or 25 sec after the beginning of the swallow, measured with or without baseline correction, respectively, and time from onset of swallow to 50% of peak activity.

RESULTS

Both visual and quantitative analysis showed a highly significant (p < 0.001) difference between the patient group and the control group. Visual analysis was best reflected by the residual activity 25 sec after the beginning of the swallow without correction for background. Receiver operating characteristic curves were used to study the ability to separate the two groups using visual or quantitative analysis. A high rate of positive tests in the patient group was achieved only at the cost of a relatively high rate of positive tests in the control group.

CONCLUSION

Our results indicate high variability in esophageal motility in controls. This variability impairs the possibilities of developing a screening test to identify asymptomatic patients early in the disease course.