A short history from Karelia study to biodiversity and public health interventions

Contact with natural environments enriches the human microbiome, promotes immune balance and protects against allergies and inflammatory disorders. In Finland, the allergy & asthma epidemic became slowly visible in mid 1960s. After the World War II, Karelia was split into Finnish and Soviet Union (now Russia) territories. This led to more marked environmental and lifestyle changes in the Finnish compared with Russian Karelia. The Karelia Allergy Study 2002–2022 showed that allergic conditions were much more common on the Finnish side. The Russians had richer gene-microbe network and interaction than the Finns, which associated with better balanced immune regulatory circuits and lower allergy prevalence. In the Finnish adolescents, a biodiverse natural environment around the homes associated with lower occurrence of allergies. Overall, the plausible explanation of the allergy disparity was the prominent change in environment and lifestyle in the Finnish Karelia from 1940s to 1980s. The nationwide Finnish Allergy Programme 2008–2018 implemented the biodiversity hypothesis into practice by endorsing immune tolerance, nature contacts, and allergy health with favorable results. A regional health and environment programme, Nature Step to Health 2022–2032, has been initiated in the City of Lahti, EU Green Capital 2021. The programme integrates prevention of chronic diseases (asthma, diabetes, obesity, depression), nature loss, and climate crisis in the spirit of Planetary Health. Allergic diseases exemplify inappropriate immunological responses to natural environment. Successful management of the epidemics of allergy and other non-communicable diseases may pave the way to improve human and environmental health.

Managing the allergy and asthma epidemic in 2020s-Lessons from the Finnish experience

In Finland, a systematic public health programme was implemented from 2008 to 2018 to mitigate the burden of allergic disorders by revisiting the prevention strategy. Allergy health and contacts with natural environment were emphasized to promote immunological and psychological resilience instead of poorly justified avoidance. Allergy management practices were improved and low‐valued recommendations for care, for example for food allergy, were revised. Patients and families were empowered to use guided self‐management to proactively stop symptom exacerbations. A professional non‐governmental organization implemented the nationwide education for healthcare and patient NGOs for patients, families and lay public. In healthcare, the work supporting allergic patients and families was organized towards common goals and integrated into everyday work without extra costs. Reaching the predefined goals was followed by employing the national healthcare registers and questionnaire surveys. Governmental bodies contributed with kick‐off funding, which was supplemented by private funding. International collaboration, for example with the European patient organization (EFA), increased awareness of the Finnish action and predisposed it for peer review. The 10‐year results are favourable, patients are less disabled, practices and attitudes in healthcare have changed, and major cost savings have been obtained. Views of the lay public and patients are slow to move, however. Local multidisciplinary allergy teams were set up to continue the activities also after the Programme. Changes in environment and lifestyle in the last 50 years are the main reasons for the allergy rise. The Finnish experience may help to manage allergic diseases, improve nature relatedness in the fast‐urbanizing world, combat nature loss and reduce the disease burden.

The Finnish Allergy Program 2008-2018: Society-wide proactive program for change of management to mitigate allergy burden

A 10-year national program to improve prevention and management of allergic diseases and asthma was implemented in Finland (population 5.5. million) in 2008-2018. The main aim was to reduce the long-term burden of these conditions. The strategy was changed from traditional avoidance to tolerance and resilience of the population. Health was endorsed instead of medicalization of mild symptoms. Disease severity was reevaluated, and disabling clinical manifestations were given high priority. For health care, 5 quantitative goals and 1 qualitative goal were set. For each of the goals, specific tasks, tools, and outcome evaluation were stipulated. During the program, 376 educational sessions gathered 24,000 health care participants. An information campaign targeted the lay public, and social media was used to contact people. In the 10 years of the program, the prevalence of allergic diseases and asthma leveled off. Asthma caused fewer symptoms and less disability, and 50% fewer hospital days. Food allergy diets in day care and schools decreased by half. Occupational allergies were reduced by 45%. In 2018, the direct and indirect costs of allergic diseases and asthma ranged from €1.5 billion to €1.8 billion, with the 2018 figures being 30% less than in the respective figures in 2007. The Finnish proactive and real-world intervention markedly reduced the public health burden of allergic disorders. The allergy paradigm was revisited to improve management with systematic education.

Digital transformation of health and care to sustain Planetary Health: The MASK proof-of-concept for airway diseases-POLLAR symposium under the auspices of Finland's Presidency of the EU, 2019 and MACVIA-France, Global Alliance against Chronic Respiratory Diseases (GARD, WH0) demonstration project, Reference Site Collaborative Network of the European Innovation Partnership on Active and Healthy Ageing

In December 2019, a conference entitled “Europe That Protects: Safeguarding Our Planet, Safeguarding Our Health” was held in Helsinki. It was co-organized by the Finnish Institute for Health and Welfare, the Finnish Environment Institute and the European Commission, under the auspices of Finland’s Presidency of the EU. As a side event, a symposium organized as the final POLLAR (Impact of air POLLution on Asthma and Rhinitis) meeting explored the digital transformation of health and care to sustain planetary health in airway diseases. The Finnish Allergy Programme collaborates with MASK (Mobile Airways Sentinel NetworK) and can be considered as a proof-of-concept to impact Planetary Health. The Good Practice of DG Santé (The Directorate-General for Health and Food Safety) on digitally-enabled, patient-centred care pathways is in line with the objectives of the Finnish Allergy Programme. The ARIACARE-Digital network has been deployed in 25 countries. It represents an example of the digital cross-border exchange of real-world data and experience with the aim to improve patient care. The integration of information technology tools for climate, weather, air pollution and aerobiology in mobile Health applications will enable the development of an alert system. Citizens will thus be informed about personal environmental threats, which may also be linked to indicators of Planetary Health and sustainability. The digital transformation of the public health policy was also proposed, following the experience of the Agency for Health Quality and Assessment of Catalonia (AQuAS).

Propagule pressure increase and phylogenetic diversity decrease community's susceptibility to invasion

BACKGROUND

Invasions pose a large threat to native species, but the question of why some species are more invasive, and some communities more prone to invasions than others, is far from solved. Using 10 different three-species bacterial communities, we tested experimentally if the phylogenetic relationships between an invader and a resident community and the propagule pressure affect invasion probability.

RESULTS

We found that greater diversity in phylogenetic distances between the members of resident community and the invader lowered invasion success, and higher propagule pressure increased invasion success whereas phylogenetic distance had no clear effect. In the later stages of invasion, phylogenetic diversity had no effect on invasion success but community identity played a stronger role.

CONCLUSIONS

Taken together, our results emphasize that invasion success does not depend only on propagule pressure, but also on the properties of the community members. Our results thus indicate that invasion is a process where both invader and residing community characters act in concert.

" Nature step" to prevent noncommunicable inflammatory disease

The prevention of many diseases has significantly improved by intervening in known risk factors. However, the causes of the increase in allergy and type 1 diabetes are unknown. These diseases are often associated with a low-grade inflammation and immunological imbalance. The lifestyle and environment of urbanized populations have changed causing imbalance in the human normal flora and affecting immune regulation. We discuss everyday factors affecting immune regulation, using allergy as an example. Health may be promoted through the "nature step", by supporting the connection between humans and nature.

Experimental evolution in fluctuating environments: tolerance measurements at constant temperatures incorrectly predict the ability to tolerate fluctuating temperatures

The ability to predict the consequences of fluctuating environments on species distribution and extinction often relies on determining the tolerances of species or genotypes in different constant environments (i.e. determining tolerance curves). However, very little is known about the suitability of measurements made in constant environments to predict the level of adaptation to rapidly fluctuating environments. To explore this question, we used bacterial clones adapted to constant or fluctuating temperatures and found that measurements across a range of constant temperatures did not indicate any adaptation to fluctuating temperatures. However, adaptation to fluctuating temperatures was only apparent if growth was measured during thermal fluctuation. Thus, tolerance curves based on measurements in constant environments can be misleading in predicting the ability to tolerate fast environmental fluctuations. Such complications could lead to false estimates of the genetic merits of genotypes and extinction risks of species due to climate change-induced thermal fluctuations.

Salt chamber treatment is ineffective in treating eosinophilic inflammation in asthma

BACKGROUND

We have shown that salt chamber treatment reduces airway hyper-responsiveness as an add-on therapy in adult asthmatics on inhaled corticosteroids.

METHODS

We assessed whether this effect is due to the suppression of eosinophilic airway inflammation. Thirty-nine adult asthmatics on inhaled corticosteroids were randomized to receive active salt chamber treatment with low-salt treatment 6.6 mg/m(3) (n = 14), high-salt treatment 10.8 mg/m(3) (n = 15) or placebo 0.3 mg/m(3) (n = 10) 10 times in a 2 weeks' period in a double-blind manner.

RESULTS

The level of induced sputum eosinophilic cationic protein μg/l, was 3070 before and 4651 after the low-salt treatment period, on average. In the high-salt treatment group, it was 12 192 μg/l vs 11 803 and in the placebo group 3942 vs 4144, respectively. Salt chamber treatment had no effect on sputum eosinophil or neutrophil cell numbers.

CONCLUSIONS

The reduction in hyper-responsiveness observed in the previous study is probably not due to the effect on eosinophilic inflammation.

The Finnish Allergy Programme 2008-2018 - scientific rationale and practical implementation

There are no nationwide, comprehensive public health programmes on allergic disorders with set goals and systematic follow-up. The Finnish initiative is based on the idea that the so called allergy epidemic in modern, urban societies is caused by inadequately developed or broken tolerance. The immune system is not trained to make the difference between danger and non-danger (allergy) or the difference between self and non-self (autoimmune diseases). The immune dysfunction leads to inappropriate inflammatory responses and clinical symptoms. The 10-year implementation programme is aimed to reduce burden of allergies both at the individual and societal levels. This is done by increasing both immunological and psychological tolerance and changing attitudes to support health instead of medicalising common and mild allergy symptoms. Severe forms of allergy are in special focus, e.g. asthma attacks are prevented proactively by improving disease control with the help of guided self-management. Networking of allergy experts with primary care doctors and nurses as well with pharmacists is the key for effective implementation. Non-governmental organizations have started a campaign to increase allergy awareness and knowledge among patients and general public. It is time to act, when allergic individuals are becoming a majority of Western populations and their numbers are in rapid increase worldwide. The first results of the Finnish Programme indicate that allergy burden can be reduced with relatively simple means.

Dispersive Fourier Transform Spectroscopy Of Free-Standing Porous Silicon Films

We have investigated optical constants of free-standing porous silicon films by dispersive Fourier transform spectroscopy (DFTS) in the NIR-VIS range. This allows the spectral variation of both the absorption coefficient and the refractive index of a material to be determined from the measurements of the attenuation and phase shift imposed on an electromagnetic wave by its interaction with a specimen. Using these optical constants, we have studied the complex dielectric function and the complex conductivity. To avoid the additive error in the absorption spectra arising from the pseudocoherence, we measured the transmission spectra by conventional Fourier transform spectroscopy (FTS). Using the refraction spectrum derived from the DFTS measurements, we have corrected for reflection losses in calculation of the absorption spectrum from the FTS transmission spectrum. The changes in the absorption coefficient and the refractive index due to oxidation, which is the most common aging phenomenon in porous silicon, have been studied using samples with different types of oxidization.

Effect of different mowing regimes on butterflies and diurnal moths on road verges

In northern and central Europe road verges offer alternative habitats for declining plant and invertebrate species of semi-natural grasslands. The quality of road verges as habitats depends on several factors, of which the mowing regime is one of the easiest to modify. In this study we compared the Lepidoptera communities on road verges that underwent three different mowing regimes regarding the timing and intensity of mowing; mowing in mid-summer, mowing in late summer, and partial mowing (a narrow strip next to the road). A total of 12,174 individuals and 107 species of Lepidoptera were recorded. The mid-summer mown verges had lower species richness and abundance of butterflies and lower species richness and diversity of diurnal moths compared to the late summer and partially mown verges. By delaying the annual mowing until late summer or promoting mosaic-like mowing regimes, such as partial mowing, the quality of road verges as habitats for butterflies and diurnal moths can be improved.

Improved survival after in-hospital cardiac arrest outside critical care areas

BACKGROUND

The in-hospital Utstein Guidelines may be used to evaluate resuscitation strategies. This study utilized the Utstein template prospectively to examine changes in outcome and outcome-related factors after resuscitation outside critical care areas over a 10-year period.

METHODS

Seinäjoki Central Hospital (460 beds) is a secondary hospital in Finland with acute care activities. In 1993, the in-hospital cardiac arrest management was remodelled; an intensive care unit-based resuscitation team was formed and prospective data collection began (modified according to the Utstein Guidelines in 1997). An analysis of resuscitation attempts outside critical care areas between 1993 and 2002 was performed. To monitor developments, the patients were divided into two groups (first period, 1993-97; second period, 1998-2002). Variables independently associated with survival were identified using multiple logistic regression analysis.

RESULTS

During the 10-year period, resuscitation was attempted in 183 patients. Survival to discharge was 6% during the first period and 16% during the second (P = 0.048). The corresponding figures for survival at 1 year from the event were 3% and 10% (P = 0.064). Independent predictors of survival were ventricular fibrillation or ventricular tachycardia as the initial rhythm [odds ratio (OR), 9.8; confidence interval (CI), 3.2-30.3] and cardiac arrest occurring during the second period (OR, 3.3; CI, 1.1-10.1).

CONCLUSION

Prospective Utstein style data collection proved to be a valuable tool for the evaluation of management and outcome following in-hospital cardiac arrest. Increased survival was seen over 10 years outside critical care areas. Organizational changes, including cardiopulmonary resuscitation training for ward personnel and standardized resuscitation management, may have contributed to this change.

Vacancy-impurity complexes in highly Sb-doped Si grown by molecular beam epitaxy

Positron annihilation measurements, supported by first-principles electron-structure calculations, identify vacancies and vacancy clusters decorated by 1-2 dopant impurities in highly Sb-doped Si. The concentration of vacancy defects increases with Sb doping and contributes significantly to the electrical compensation. Annealings at low temperatures of 400-500 K convert the defects to larger complexes where the open volume is neighbored by 2-3 Sb atoms. This behavior is attributed to the migration of vacancy-Sb pairs and demonstrates at atomic level the metastability of the material grown by epitaxy at low temperature.

Does the implementation of a clinical information system decrease the time intensive care nurses spend on documentation of care?

BACKGROUND

The number of intensive care units (ICU) using a clinical information system (CIS) is increasing. It is believed that replacing manual charting with an automatic documentation system allocates nurses more time for patient care. The objective of this study was to measure changes in nurses' working time utilization after the implementation of a CIS in a polyvalent ICU of a large Finnish central hospital.

METHODS

An activity analysis-based comparison of the ICU nurses' working time utilization before and after the implementation of a CIS.

RESULTS

After the implementation of a CIS the total time the nurses spent on documentation of nursing care increased by 3.6% (NS), 15 min per shift of 8 h per nurse. The total time they spent on patient care increased by 5.5% (P < 0.05), 21 min. Intensive care nursing activities increased by 3.7% (P < 0.05), 14 min. The length of the nurses' ICU experience had some effect on these figures. The demand for nurse labor remained constant.

CONCLUSIONS

After the implementation of a CIS, an increase in the time nurses spent on documentation of care was detected, which suggests a need for further development of the system. As all the measured time changes were relatively small, any plans to reduce the ICU staff number with the aid of computers were not justified.

Formation of thermal vacancies in highly As and P doped Si

Using positron annihilation measurements we observed the formation of thermal vacancies in highly As and P doped Si. The vacancies start to form at temperatures as low as 650 K and are mainly undecorated at high temperatures. Upon cooling the vacancies form stable vacancy-impurity complexes such as V-As3. We determine the vacancy formation energy of E(f)=1.1(2) eV and the migration energy of E(m)=1.2(1) eV in highly doped Si. By associating these values with the vacancy-impurity pair, we get an estimate of 2.8(3) eV for the formation energy of an isolated neutral monovacancy in intrinsic Si.

Ga sublattice defects in (Ga,Mn)As: thermodynamical and kinetic trends

We have used positron annihilation spectroscopy and infrared absorption measurements to study the Ga sublattice defects in epitaxial Ga(1-x)MnxAs with Mn content varying from 0% to 5%. We show that the Ga vacancy concentration decreases and As antisite concentration increases with increasing Mn content. This is in agreement with thermodynamical considerations for the electronic part of the formation energy of the Ga sublattice point defects. However, the absolute defect concentrations imply that they are determined rather by the growth kinetics than by the thermodynamical equilibrium. The As antisite concentrations in the samples are large enough to be important for compensation and magnetic properites. In addition, the Ga vacancies are likely to be involved in the diffusion and clustering of Mn at low annealing temperatures.

Evidence of the Zn vacancy acting as the dominant acceptor in n-type ZnO

We have used positron annihilation spectroscopy to determine the nature and the concentrations of the open volume defects in as-grown and electron irradiated (E(el)=2 MeV, fluence 6 x 10(17) cm(-2)) ZnO samples. The Zn vacancies are identified at concentrations of [V(Zn)] approximately 2 x 10(15) cm(-3) in the as-grown material and [V(Zn)] approximately 2 x 10(16) cm(-3) in the irradiated ZnO. These concentrations are in very good agreement with the total acceptor density determined by temperature dependent Hall experiments. Thus, the Zn vacancies are dominant acceptors in both as-grown and irradiated ZnO.

Prevalence of work-aggravated symptoms in clinically established asthma

This population-based cross-sectional survey assessed the prevalence of work-aggravated asthma symptoms and the effect of the work environment on the aggravation of symptoms of established asthma. A questionnaire was sent to 2,613 persons (aged 20-65 yrs) with asthma. The analyses were restricted to the 969 respondents who were currently employed. The effect of occupational exposure on the aggravation of asthma symptoms at work was assessed according to both self-reported and expert-evaluated exposure. Approximately 21% of the respondents reported work-aggravated asthma symptoms at least weekly during the past month. The prevalence of those with work-aggravated symptoms increased by age, self-reported occupational exposure to dusts, abnormal temperatures or poor indoor air quality, physically strenuous work, and chemicals, and expert-evaluated probability of daily occupational exposure to airborne dusts, gases or fumes. Aggravation of asthma symptoms at work is common among employed adults with asthma. Both self-reported and expert-evaluated exposure to dusts, abnormal temperatures or poor indoor air quality, physically strenuous work, and chemicals explained the significant worsening of symptoms. The findings suggest a marked role of the work environment in the aggravation of symptoms of established asthma.

Vacancy defects as compensating centers in Mg-doped GaN

We apply positron annihilation spectroscopy to identify V(N)-Mg(Ga) complexes as native defects in Mg-doped GaN. These defects dissociate in postgrowth annealings at 500-800 degrees C. We conclude that V(N)-Mg(Ga) complexes contribute to the electrical compensation of Mg as well as the activation of p-type conductivity in the annealing. The observation of V(N)-Mg(Ga) complexes confirms that vacancy defects in either the N or Ga sublattice are abundant in GaN at any position of the Fermi level during growth, as predicted previously by theoretical calculations.

Risk of asthma among Finnish patients with occupational rhinitis

STUDY OBJECTIVES

To determine the risk of asthma among patients with occupationally induced rhinitis.

DESIGN

Patients with confirmed occupational rhinitis were followed for asthma incidence through register linkage. Patients with other occupational diseases were used as a reference population.

SUBJECTS

Patients entered into the Finnish Register of Occupational Diseases in from 1988 to 1999 for occupational rhinitis (n = 3,637) or other occupational disease (n = 31,457) were observed until December 31, 2000, through two national registers of individuals who were eligible for the reimbursement of asthma medication and the Population Register Center.

METHODS

Incidence rates of asthma were calculated, and a log-linear model, adjusted for age, gender, and occupation, was used to estimate the relative risks (RRs) of asthma among those with occupational rhinitis compared to those with other occupational diseases.

RESULTS

There were 420 and 972 incident cases of asthma, respectively, among those with occupational rhinitis and the reference population. The crude RR of asthma was 4.8 (95% confidence interval [CI], 4.3 to 5.4) for all patients with occupational rhinitis, 5.4 (95% CI, 4.8 to 6.2) for those with occupational rhinitis accepted for compensation, and 3.7 (95% CI, 3.1 to 4.5) for patients with unaccepted occupational rhinitis. The RR varied according to occupation and was the highest among farmers and wood workers, both groups having a sevenfold risk. The risk was especially high during the year following notification, but a roughly threefold risk persisted several years thereafter.

CONCLUSIONS

Patients with occupationally induced rhinitis have a high risk of asthma, but further studies are needed to establish the effect of preventive interventions.

Incidence of asthma among Finnish construction workers

We wanted to explore the risk of asthma among male workers of the construction industry. All Finnish male construction industry workers and all those employed in administrative work were followed for asthma incidence through a register linkage in 1986 through 1998. Age-adjusted relative risks (RR) were estimated for 24 construction occupations. The risk was increased in nearly all construction occupations studied, but it was highest among welders and flame cutters (RR 2.34), asphalt roofing workers (RR 2.04), plumbers (RR 1.90), and brick layers and tile setters (RR 1.83). Only 45 (2%) of the cases of asthma among construction workers had been recognized as occupational asthma. Construction industry workers have an increased risk of adult-onset persistent asthma and cases of occupational asthma caused by well-established causative agents have only a minor contribution to this overall asthma excess.

Formation of vacancy-impurity complexes by kinetic processes in highly As-doped Si

Positron annihilation experiments have been applied to verify the formation mechanism of electrically inactive vacancy-impurity clusters in highly n-type Si. We show that the migration of V-As pairs at 450 K leads to the formation of V-As2 complexes, which in turn convert to stable V-As3 defects at 700 K. These processes manifest the formation of V-As3 as the dominant vacancy-impurity cluster in highly n-type Si. They further explain the electrical deactivation and clustering of As in epitaxial or ion-implanted Si during postgrowth heat treatment at 700 K.

Light scattering by wood fibers

We consider the scattering of light by single wood fibers both theoretically and experimentally. We describe the size and the shape distributions and the internal structure and chemical composition of the wood fibers. We have modeled the random shape of the hollow, cylindrical wood fiber by using multivariate lognormal statistics. We have computed wood-fiber absorption and scattering cross sections, asymmetry parameters, and scattering phase matrices in the ray-optics approximation. Finally, we have provided experimental results from angular scattering measurements for wood fibers and present what we believe is the first comparison between these measurements and ray-optics computations for Gaussian random wood-fiber models. In spite of the complicated internal structure of the wood fiber, our model together with the ray-optics treatment explains the scattering measurements surprisingly well.

Occupational IgE-mediated allergy to Tribolium confusum (confused flour beetle)

BACKGROUND

We report on IgE-mediated allergy in a worker caused by Tribolium confusum (confused flour beetle). These beetles lived in the "old" flour to which he was exposed in his work.

CASE REPORT

A 35-year-old, nonatopic mechanic in a rye crispbread factory developed rhinitis, conjunctivitis, and asthmatic symptoms, as well as urticaria on his wrists, lower arms, hands, neck, and face, during the maintenance and repair of machines contaminated by flour. This flour had been in and on the machines for a long time, and it contained small beetles. The patient did not suffer any symptoms when handling fresh, clean flour.

RESULTS

Skin prick tests with standard environmental allergens, storage mites, enzymes, flours, and molds were negative. A prick test with flour from the machines gave a 10-mm reaction. An open application of the same flour caused urticarial whealing on the exposed skin. Prick tests with fresh flour from the factory were negative. A prick test with minced T. confusum from the flour in the machines gave a 7-mm reaction. Histamine hydrochloride 10 mg/ml gave a 7-mm reaction. Specific serum IgE antibodies to T. confusum were elevated at 17.2 kU/l. Prick tests with the flour from the machines were negative in five control patients.

CONCLUSIONS

The patient had occupational contact urticaria, rhinitis, conjunctivitis, and asthmatic symptoms from exposure to flour. His symptoms were caused by immediate allergy to the beetle T. confusum. Immediate allergy to this beetle has rarely been reported in connection with respiratory symptoms, but it may be more common. Contact urticaria from this source has not been reported before.

Molecular genetics of the long QT syndrome: two novel mutations of the KVLQT1 gene and phenotypic expression of the mutant gene in a large kindred

At least three different gene loci were recently shown to account for the long QT syndrome (LQTS), a monogenic disorder with altered myocardial repolarization and occurrence of life-threatening cardiac arrhythmias. We screened 44 unrelated probands for mutations of the gene encoding the cardiac potassium channel KVLQT1 using single-strand conformational polymorphism (SSCP) and subsequent DNA sequencing. Two different mutations, T182I and D188N, were identified in two separate pedigrees. Cosegregation of the mutation with the disease phenotype was evident in both families. No mutations were identified at codon 212, previously suggested to represent a mutational hot spot of the KVLQT1 channel, in any of the 44 probands. The large pedigree with the D188N mutation (30 affected and 43 nonaffected individuals) permitted an analysis of expression of the mutant gene in its documented carriers. Although the mean (+/-SD) QTc interval was markedly longer in affected (484+/-38 ms) than in nonaffected individuals (406+/-27 ms, P < 0.001), there was a marked overlapping of individual values in these two groups. QTc values in symptomatic and asymptomatic carriers of the mutant gene were not significantly different. In conclusion, we have identified two novel mutations of the KVLQT1 component of a cardiac potassium channel. Our data support the functional significance of the pore-S6 domain of this membrane protein and emphasize the diagnostic usefulness of DNA analyses in families with LQTS.

Time-resolved fluorometric assay for leukocyte adhesion using a fluorescence enhancing ligand

A new 96-well microtiter plate, time-resolved fluorometric assay was developed to measure leukocyte adhesion in vitro. The assay is based on loading leukocytes with a fluorescence enhancing ligand 2,2':6', 2"-terpyridine-6,6"-dicarboxylic acid (TDA), which in its acetoxymethyl ester form readily diffuses through the cell membrane. After hydrolysis by nonspecific intracellular esterases, the impermeable TDA accumulates inside the cells. When the TDA-labeled adherent leukocytes are lysed, the ligand is released and reacts with europium present in the lysis solution to produce a highly fluorescent and stable chelate. The fluorescence signal can be measured by time-resolved fluorometry and correlates directly with the number of adherent cells. In this study, we have optimized both the TDA-labeling and adhesion assay conditions in isolated human neutrophils. Furthermore, we have compared the assay with a traditional microscopic counting method. This time-resolved fluorometric assay provides a rapid, reproducible and convenient method for the routine analysis of leukocyte adhesion.

Systemic suppression of human peripheral blood phagocytic leukocytes after whole-body UVB irradiation

We examined systemic effects of whole-body UVB irradiation on human peripheral blood phagocytes. We found that 24 h after a single erythemal dose of UVB radiation two phagocyte functions, adhesion and phagocytosis, were reduced by 50%. This functional suppression was accompanied by a significant decrease in the expression of complement receptors (CR1 and CR3) and IgG Fc receptors (FcRII and FcRIII). The greatest reduction (47%) was observed in CR3, which is important for both adhesion and phagocytosis. A kinetic analysis showed that both CR1 and CR3 levels started to decrease 15 min after the UVB exposure, reaching the lowest levels at 4.5- and 24-h time points, respectively. The down-modulation of CRs after whole-body UVB exposure was not due to a defective receptor synthesis or translocation from internal stores to plasma membrane because the maximal CR levels in stimulated cells were not affected by UVB. No change in the serum soluble ICAM-1 was detected after UVB, which rules out CD1 1b epitope masking by sICAM-1. UVB did not release low-receptor-density myeloid progenitor cells from storage pools into circulation. Interleukin 10, a mediator of UVB-induced immunosuppression, was unable to modulate CR expression in vitro. When seven suberythemal whole-body UVB exposures were given repeatedly within 2 weeks, a significant decrease in CR expression was seen, which was greatest after three irradiations. Our data suggest that an exposure to UVB has systemic effects in humans which, possibly due to the down-modulation of preexisting cell-surface receptors, suppress some important functions of circulating phagocytic cells.

Evaluation of QT interval duration and dispersion and proposed clinical criteria in diagnosis of long QT syndrome in patients with a genetically uniform type of LQT1

OBJECTIVES

This study investigated the ability of QT duration, QT dispersion (QTD) and clinical diagnostic criteria to correctly identify genetically documented LQT1 type long QT syndrome (LQTS) patients, and to separate symptomatic and asymptomatic LQT1 patients.

BACKGROUND

Ventricular repolarization has played an essential role both in diagnosis and risk assessment of LQTS. Today, molecular genetic techniques permit unequivocal identification of many LQTS patients.

METHODS

QT interval and QTD in 12 symptomatic and 18 asymptomatic LQT1 patients and their 43 healthy relatives were evaluated. The sensitivity and specificity of upper normal limits of QT interval, two QT interval adjustment methods (Bazett's and Fridericia's formulas), and the proposed clinical criteria for LQTS were assessed. Occurrence of a mutant (D188N) KVLQT1 gene was considered as the basis of classification into affected and nonaffected individuals.

RESULTS

Diagnostic sensitivity and specificity values were 90% and 88% using Bazett's formula, and 80% and 100% using Fridericia's cubic root formula or upper normal limits for QT interval. Suggested diagnostic criteria for LQTS reached 100% specificity, but 47% of the DNA-documented LQT1 patients were classified into the category of low or intermediate probability of LQTS. QT interval and heart rate did not differ between symptomatic (464 +/- 47 ms, 70 +/- 9 min(-1)) and asymptomatic 460 +/- 41 ms, 65 +/- 13 min(-1)) LQT1 patients. QTD was increased in symptomatic LQT1 patients compared to unaffected relatives (66 +/- 48 vs. 37 +/- 15 ms, p = 0.02), but symptomatic patients LQT1 did not differ from asymptomatic (45 +/- 19 ms).

CONCLUSIONS

Not all LQT1 patients can be distinguished from healthy relatives by assessment of QT duration or clinical criteria. Presence of LQT1 gene can carry the risk of cardiac events even with no or only marginal prolongation of QT interval.

Increased adhesion of peripheral blood neutrophils from patients with localized juvenile periodontitis

Adhesion of peripheral blood neutrophils from 5 patients with localized juvenile periodontitis (LJP) and age- and gender-matched healthy controls was measured using a semi-automated 96-well microtiter plate assay method. Both unstimulated and formyl-methionyl-leucyl-phenylalanine (FMLP, 10-1000 nM)-stimulated neutrophils from LJP patients showed in general higher adhesion than did their controls. After 15-60 min incubation with 100 and 1000 nM FMLP the numbers of adherent cells were significantly (p < 0.05), 2.1-2.6-fold higher in LJP patients than in controls. Neutrophils from these LJP patients showed also enhanced respiratory burst activity in response to unopsonized zymosan stimulation. To test whether a decrease in intracellular diacylglycerol (DAG) kinase activity could account for the increased neutrophil adhesion of LJP patients normal neutrophils were treated with R59949 (10 microM), a DAG-kinase inhibitor. Both unstimulated and FMLP-stimulated normal neutrophils showed significantly (p < 0.05) enhanced adhesion after R59949-treatment. Taken together, our data indicate that neutrophils from the 5 LJP patients investigated here exhibit 2 parallel hyperactivities, namely increased adhesion and enhanced production of reactive oxygen species. Furthermore, our present and previous (Hurttia et al., J Periodont Res 1997; 32: 401-407) results suggest that the observed neutrophil functional abnormalities in some LJP patients may be associated with decreased cellular DAG-kinase activity. It is proposed that the hyperadherent and -active neutrophils may promote the development of LJP by causing tissue damage in the periodontium.