Tropical altitudinal gradient soil organic carbon and nitrogen estimation using Specim IQ portable imaging spectrometer

The largest actively cycling terrestrial carbon pool, soil, has been disturbed during latest centuries by human actions through reduction of woody land cover. Soil organic carbon (SOC) content can reliably be estimated in laboratory conditions, but more cost-efficient and mobile techniques are needed for large-scale monitoring of SOC e.g. in remote areas. We demonstrate the capability of a mobile hyperspectral camera operating in the visible-near infrared wavelength range for practical estimation of soil organic carbon (SOC) and nitrogen content, to support efficient monitoring of soil properties. The 191 soil samples were collected in Taita Taveta County, Kenya representing an altitudinal gradient comprising five typical land use types: agroforestry, cropland, forest, shrubland and sisal estate. The soil samples were imaged using a Specim IQ hyperspectral camera under controlled laboratory conditions, and their carbon and nitrogen content was determined with a combustion analyzer. We use machine learning for estimating SOC and N content based on the spectral images, studying also automatic selection of informative wavelengths and quantification of prediction uncertainty. Five alternative methods were all found to perform well with a cross-validated R² of approximately 0.8 and an RMSE of one percentage point, demonstrating feasibility of the proposed imaging setup and computational pipeline.

Oncological outcomes before and after the extralevator abdominoperineal excision era in rectal cancer patients treated with abdominoperineal excision in a single centre, high volume unit

AIM

The extralevator abdominoperineal excision (ELAPE) has been expected to reduce the risk of positive circumferential resection margins (CRMs) and local recurrence in locally advanced distal rectal cancer. The aim was to determine whether there is any difference in local recurrence rates between patients who were operated on for distal rectal cancer before and after the introduction of ELAPE in our unit.

PATIENTS AND METHODS

In all, 206 patients with distal rectal cancer without distant metastases (T1-4N0-2M0) were treated with curative intent. The patients were divided into two cohorts operated in 2000-2007 (A) and 2008-2014 (B). The ELAPE procedure was introduced in 2008. Since then, it has been used in cases of T4 and T3 tumours with threatened margins. In T1-T3 tumours without threatened margins a conventional abdominal perineal excision has been performed.

RESULTS

There was no significant difference in overall survival or cancer-specific survival between the two time periods. The local recurrence rate was 15.5% in group A and 6.7% in group B (P = 0.048), although there was no significant difference in the cumulative local recurrence rate. Intra-operative tumour perforation occurred significantly more often during the earlier period when ELAPE was not in use: group A 15/71 (21.1%) vs group B 11/135 (8.1%), P = 0.01. CRM was positive more often in group A (16.4%) vs group B (7.4%), P = 0.054.

CONCLUSION

The local recurrence rate, intra-operative tumour perforation and positive CRM rate were significantly lower during the later period when more extensive surgery (ELAPE) was performed for locally advanced T3-T4 rectal cancer with threatened margins.

Oncological results of extended resection for locally advanced rectal cancer: the value of postirradiation MRI in predicting local recurrence

AIM

The primary purpose of this study was to analyse the overall survival and local recurrence rate after extended resection of locally advanced rectal cancer. The second aim was to determine the ability of the response to radiological irradiation to predict R0 resection.

METHOD

A retrospective study was performed of 94 consecutive patients with locally advanced rectal cancer operated on at the Helsinki University Hospital, Helsinki, Finland between 2005 and 2013. Data were collected from patient records. All patients were treated with an en bloc resection. Sixty-two patients received preoperative long-term chemoradiotherapy.

RESULTS

The 30-day mortality was 3.2%. Local recurrence occurred in 10 (10.6%) patients. The cumulative 1-, 3- and 5-year overall survival to each year was 89.4%, 68.3% and 51.8%. The most important prognostic factor for both local recurrence (P = 0.006) and survival (P = 0.003) was an R0 resection. A poor or no response seen on posttreatment MRI predicted local recurrence (P = 0.045) and decreased disease-free survival in patients treated curatively (P = 0.052). The histological tumour regression grade was not associated with local recurrence or survival.

CONCLUSION

Multivisceral resection offers a 5-year survival of over 50% and local control of advanced rectal cancer in nearly 90% of carefully selected patients.

Systemic blockade of ACVR2B ligands prevents chemotherapy-induced muscle wasting by restoring muscle protein synthesis without affecting oxidative capacity or atrogenes

Doxorubicin is a widely used and effective chemotherapy drug. However, cardiac and skeletal muscle toxicity of doxorubicin limits its use. Inhibiting myostatin/activin signalling can prevent muscle atrophy, but its effects in chemotherapy-induced muscle wasting are unknown. In the present study we investigated the effects of doxorubicin administration alone or combined with activin receptor ligand pathway blockade by soluble activin receptor IIB (sACVR2B-Fc). Doxorubicin administration decreased body mass, muscle size and bone mineral density/content in mice. However, these effects were prevented by sACVR2B-Fc administration. Unlike in many other wasting situations, doxorubicin induced muscle atrophy without markedly increasing typical atrogenes or protein degradation pathways. Instead, doxorubicin decreased muscle protein synthesis which was completely restored by sACVR2B-Fc. Doxorubicin administration also resulted in impaired running performance without effects on skeletal muscle mitochondrial capacity/function or capillary density. Running performance and mitochondrial function were unaltered by sACVR2B-Fc administration. Tumour experiment using Lewis lung carcinoma cells demonstrated that sACVR2B-Fc decreased the cachectic effects of chemotherapy without affecting tumour growth. These results demonstrate that blocking ACVR2B signalling may be a promising strategy to counteract chemotherapy-induced muscle wasting without damage to skeletal muscle oxidative capacity or cancer treatment.

Geological control of floristic composition in Amazonian forests

AIM: Conservation and land-use planning require accurate maps of patterns in species composition and an understanding of the factors that control them. Substantial doubt exists, however, about the existence and determinants of large-area floristic divisions in Amazonia. Here we ask whether Amazonian forests are partitioned into broad-scale floristic units on the basis of geological formations and their edaphic properties. LOCATION: Western and central Amazonia. METHODS: We used Landsat imagery and Shuttle Radar Topography Mission (SRTM) digital elevation data to identify a possible floristic and geological discontinuity of over 300 km in northern Peru. We then used plant inventories and soil sampling to document changes in species composition and soil properties across this boundary. Data were obtained from 138 sites distributed along more than 450 km of road and river. On the basis of our findings, we used broad-scale Landsat and SRTM mosaics to identify similar patterns across western and central Amazonia. RESULTS: The discontinuity identified in Landsat and SRTM data corresponded to a 15-fold change in soil cation concentrations and an almost total change in plant species composition. This discontinuity appears to be caused by the widespread removal of cation-poor surface sediments by river incision to expose cation-rich sediments beneath. Examination of broad-scale Landsat and SRTM mosaics indicated that equivalent processes have generated a north-south discontinuity of over 1500 km in western Brazil. Due to similarities with our study area, we suggest that this discontinuity represents a chemical and ecological limit between western and central Amazonia. MAIN CONCLUSIONS: Our findings suggest that Amazonian forests are partitioned into large-area units on the basis of geological formations and their edaphic properties. The evolution of these units through geological time may provide a general mechanism for biotic diversification in Amazonia. These compositional units, moreover, may correspond to broad-scale functional units. The existence of large-area compositional and functional units would suggest that protected-area, carbon sequestration, and other land-use strategies in Amazonia be implemented on a region-by-region basis. The methods described here can be used to map these patterns, and thus enable effective conservation and management of Amazonian forests.

Intake of vitamin D by Finnish children aged 3 months to 3 years in relation to sociodemographic factors

OBJECTIVE

To study the total daily intake of vitamin D from food and supplements among Finnish children aged 3 months to 3 years, the dietary sources of vitamin D and the association between vitamin D intake and sociodemographic factors.

SUBJECTS AND METHODS

The subjects are participants in the Finnish Type I Diabetes Prediction and Prevention Nutrition Study born between October 1997 and October 1998. At the age of 3 and 6 months, 1, 2 and 3 years, 342 (72% of the invited families), 298 (63%), 267 (56%), 233 (49%) and 209 (44%) families, respectively, participated in the present study. Food consumption was assessed by a 3-day food record. A structured questionnaire was used to record the parents' socioeconomic status.

RESULTS

The mean dietary vitamin D intake exceeded the recommendation (10 microg/day) at the age of 3 (11.0 microg) and 6 months (12.0 microg), but decreased thereafter being 9.8, 5.0 and 4.1 microg at 1, 2 and 3 years of age, respectively. Among the children 91, 91, 81, 42 and 26% used vitamin D supplements at the age of 3 and 6 months, and 1, 2 and 3 years, respectively. In children not using vitamin D supplements, vitamin D intake was less than 10 microg/day at all ages. Vitamin D intake from food did not differ in children who used and did not use vitamin D supplements. Vitamin D supplements were the main source of vitamin D intake in all age groups studied, followed by vitamin D-fortified infant formula in 3-month-olds and infant formula and baby foods in 6-month-olds. After the age of 1 year, the most important food sources of vitamin D were margarine, fish, baby foods, low-fat milk and eggs. Sociodemographic factors, especially the number of children in the family and maternal age, were associated with the total vitamin D intake and vitamin D supplement use.

CONCLUSION

Vitamin D supplements are not used according to the dietary recommendations in a substantial proportion of Finnish children.

Impact of nutrition counselling on nutrition knowledge and nutrient intake of 7- to 9-y-old children in an atherosclerosis prevention project

OBJECTIVE

To assess the impact of nutrition counselling given to 7.5- to 9-y-old children and their parents on children's nutrition knowledge and nutrient intakes.

DESIGN AND SUBJECTS

The study children are participants in a prospective, randomised STRIP study (Special Turku Coronary Risk Factor Intervention Project for Children), whose aim was to decrease the intakes of saturated fat and cholesterol while increasing the intake of unsaturated fat in the intervention children from the age of 7 months onwards. Nutrition counselling was given only to the parents until the child's age of 7 y. Nutrition knowledge and nutrient intakes (total energy, total fat, saturated fat, unsaturated fat and sodium) were studied in a time-restricted cohort of 47, 7-y-old intervention and 51 control children. Thereafter, nutrition counselling was given both to the children and parents. Children's nutrition knowledge and nutrient intakes were measured again at the age of 9 y.

RESULTS

Biannual nutrition counselling given to the intervention children and the parents maintained the differences in saturated fatty acid intake attained during the intervention given to the parents alone (11.5 vs 13.3 E% (percent of energy intake), at the age of 7 y, P<0.01; 11.1 vs 13.4 E% at the age of 9 y, respectively; P<0.01). The intervention children used more polyunsaturated fatty acids at the age of 9 y than the control children (5.7 vs 5.1 E%, P=0.05). At 7 y, the intervention and control children had similar nutrition knowledge scores (total knowledge score 12.9 vs 12.0, respectively, P=0.13). After 1.5 y of nutrition intervention, at 9 y, the intervention children's nutrition knowledge was higher than that of the controls (total nutrition score 16.5 vs 13.2, respectively, P<0.001) and the ability to explain the reasons for their picture choices in the nutrition knowledge test had increased.

CONCLUSION

This study showed that only a relatively short period of counselling with low input is needed to increase in children's nutrition knowledge and ability to explain nutrition-related subjects if advice has first been given to the parents and if the parents have received reinforcement and concrete help with parent-child communication after their children have been involved in the counselling. The differences attained in nutrient intake could also be maintained.

Parental nutrition knowledge and nutrient intake in an atherosclerosis prevention project: the impact of child-targeted nutrition counselling

Most of the counselling in health care targeted at child nutrition is delivered via the parents, but little is known about the effects of such counselling on the nutrition knowledge and dietary habits of the parents. In the Special Turku Coronary Risk Factor Intervention Project for Children (STRIP), we studied how 6.5 years of child-targeted nutrition counselling affected the knowledge, attitudes and dietary habits of the parent mainly responsible for food purchase and preparation. We used a questionnaire and a 24-h recall interview in a time-restricted cohort of 98 families belonging to the intervention group and 89 families belonging to the control group in the STRIP project. After controlling for background variables, the intervention parents had better knowledge than the control parents of causal relationships between food choices and coronary heart disease and of the nutritional composition of foods. Knowledge of nutrition concepts did not differ between the two groups. The quality of fat was better in the diet of the intervention parents, they consumed less salt and they also had more knowledge concerning these subjects compared to the control parents (higher behavioural capability scores). The behavioural capability scores of the total group correlated poorly with their nutrient intakes. Thus, child-targeted nutrition intervention delivered to the parents increased parental nutrition knowledge and improved the quality of the parents' diet. However, as nutrition knowledge of the parents correlated poorly with their nutrient intakes, other factors than knowledge appear to influence parental dietary decisions.

Perinatal risk factors for hay fever--a study among 2550 Finnish twin families

Previous studies have suggested that perinatal factors influence the risk for asthma but population studies on perinatal factors and risk for hay fever are few. We studied the effect of perinatal factors on the risk for hay fever among adolescent twins by a questionnaire study involving five consecutive nation-wide birth cohorts of 16-year-old twins and their parents. The risk for parent-reported, doctor-diagnosed hay fever in the adolescents associated with several perinatal characteristics was assessed with logistic regression analysis among individuals and by a discordant pair analysis. In the univariate analysis of the birth factors, the risk for hay fever increased with increasing birth weight (p for trend = 0.048, OR for those > or = 3000 g 1.35, 95% CI 0.91-2.02 compared to those < 2000 g) and gestational age (p for trend = 0.04, OR for those born after 40 weeks of gestation 2.24, 95% CI 1.03-4.86, compared to those born before 33 weeks of gestation) and was lower in those subjects hospitalised in the neonatal period (OR 0.74, 95% CI 0.58-0.93). Because of significant interactions between parental hay fever status and birth factors (ponderal index, p = 0.03 and maternal age p = 0.04), stratified analysis were performed. The positive association between birth weight and hay fever was most obvious among adolescents with no parental history of hay fever (p for trend = 0.03). Similar, though not significant, trends were found with other birth factors among these families, whereas no such trend was found among adolescents with parental hay fever, suggesting that gestational maturity increases the risk for hay fever in the absence of genetic predisposition. However, of the perinatal factors only neonatal hospitalisation (OR 0.75, 95% CI 0.59-0.96) remained a significant risk factor for the development of hay fever, when adjusted for non-perinatal factors.

Nutrition knowledge and food intake of seven-year-old children in an atherosclerosis prevention project with onset in infancy: the impact of child-targeted nutrition counselling given to the parents

OBJECTIVE

To compare nutrition knowledge and food intake in 7-y-old intervention and control children in an atherosclerosis risk factor intervention trial after 6.5 y of nutrition counselling given to the parents.

DESIGN, SUBJECTS AND METHODS

Intervention families in the Special Turku Coronary Risk Factor Intervention Project received child-oriented nutritional counselling one to three times a year since child's age of 7 months, aimed at reduced saturated fat and cholesterol intake. Children's nutrition knowledge was analysed in a time-restricted cohort of 70 seven-y-old (34 boys) intervention children and 70 control children (40 boys) with a picture identification test. For comparison, children's food intake was evaluated using scores developed for the project that reflected quality and quantity of fat and quantity of salt in children's two or three 4-day food diaries recorded between 5.5 and 7 y of age.

RESULTS

Child-targeted nutrition counselling of the intervention families only slightly increased intervention children's knowledge of heart-healthy foods (42.6% vs 34.9% correct answers by the intervention and control children, P = 0.057). Only < or = 20% of the children were able to adequately justify their answers in the test. The food diaries of the intervention children comprised more foods low in saturated fat and high in unsaturated fat than those of the control children (57.1% vs 41.7% of the maximum score for low fat foods, P = 0.0001; 48.9% vs 37.7% for high unsaturated fat foods, P = 0.0009, respectively), but the intervention and control children consumed similar amounts of low-salt foods (P = 0.23). Nutrition knowledge and food use scores correlated poorly (r = -0.20-0.35).

CONCLUSIONS

Child-targeted nutrition counselling repeatedly given to the parents during and after child's infancy strongly influenced food choice scores of the 5.5-7-y-old children but failed to influence children's salt intake or scores in a nutrition knowledge picture test.

Near infrared reflectance spectroscopy for the fast identification of PVC-based films

Near infrared (NIR) reflectance spectroscopy was used to develop a non-destructive and rapid qualitative method for the analysis of plastic films used by the pharmaceutical industry for blistering. Three types of films were investigated: 250 microm PVC [poly(vinyl chloride)] films, 250 microm PVC films coated with 40 g m(-2) of PVDC [poly(vinylidene dichloride)] and 250 microm PVC films coated with 5 g m(-2) of TE (Thermoelast) and 90 g m(-2) of PVDC. Three analyses were carried out using different pre-treatment options and a PLS (partial least squares) algorithm. Each analysis was aimed at identifying one type of film and rejecting all types of false sample (different thickness, colour or layer). True and false samples from four plastics manufacturers were included in the calibration sets in order to obtain robust methods that were suitable regardless of the supplier. Specificity was demonstrated by testing validation sets against the methods. The tests showed 0% of type I (false negative identification) and 1% of type II errors (false positive identification) for the PVC method, 13 and 3%, respectively, for the PVC-PVDC method and no error for the PVC-TE-PVDC method. Type II errors, mostly due to the slight sensitivity of the methods to film thickness, are easily corrected by simple thickness measurements. This study demonstrates that NIR spectroscopy is an excellent tool for the identification of PVC-based films. The three methods can be used by the pharmaceutical industry or plastics manufacturers for the quality control of films used in blister packaging.

Tracking of body size from birth to late adolescence: contributions of birth length, birth weight, duration of gestation, parents' body size, and twinship

Birth weight has correlated positively with adult body mass index (BMI), but rarely have birth length, duration of gestation, or parents' body size been taken into account. The authors examined tracking of birth length and weight, adjusted for gestational age, to late adolescence, with special reference to parents' height and BMI. Longitudinal information from a nationally representative sample of Finnish twin adolescents (birth cohorts 1975-1979) and their parents was collected via questionnaires mailed when the twins were aged 16 years (n = 4,376; 2,062 males, 2,314 females) and 18 years (n = 3,917; 1,742 males, 2,175 females). The twins showed significant tracking of body size from birth to late adolescence, which was greatly influenced by their parents' body size. Height in adolescence was predicted by length and weight at birth and by parents' height, whereas BMI was predicted by birth weight and parents' BMI. An especially high risk for overweight was found for subjects of average length but a high weight at birth. These findings suggest that the intrauterine period has enduring effects on later body size but leave unresolved whether these effects are genetic or environmental.

Matrix Isolation and Ab Initio Study of the Hydrogen-Bonded H2O2-CO Complex

The structure, energetics, and infrared spectrum of the H2O2-CO complex have been studied computationally with the use of ab initio calculations and experimentally by FTIR matrix isolation techniques. Computations predict two stable conformations for the H2O2-CO complex, both of which show almost linear hydrogen bonds between the subunits. The carbon-attached HOOH-CO complex is the lower-energy form, and it has an interaction energy of -9.0 kJmol(-1) at the CCSD(T)/6-311++G(3df,3pd)// MP2/6-311++G(3df,3pd) level. The higher-energy form, HOOH-OC, has an interaction energy of 4.7 kJmol(-1) at the same level of theory. Experimentally, only the lower-energy form, HOOH-CO, was observed in Ar, Kr, and Xe matrices, and the hydrogen bonding results in substantial perturbations of the observed vibrational modes of both complex subunits. UV photolysis of the complex species primarily produces a complex between water and carbon dioxide, but minor amounts of HCO and trans-HOCO were found as well.

FT-IR breath test in the diagnosis and control of treatment of methanol intoxications

A portable Fourier transform infrared (FT-IR) multicomponent point-of-care analyzer was tested for the diagnosis of methanol intoxications. Breath analysis with FT-IR was fast and easy, and no sample preparation was needed. The analyzer was adequately sensitive and accurate in detecting and quantitating clinically relevant amounts of ethanol and methanol in the breath of seriously ill patients. FT-IR spectrometry was also suitable for nearly on-line monitoring of the exhaled ethanol and methanol during hemodialysis. The breath analysis results correlated well with blood samples. The FT-IR method used also has a traceable calibration to physical properties of the analyte, and the measured spectra can be saved for later analysis.

Vibrational Spectra of cis and trans Oxalyl Fluoride and Their Site-Selective IR-Induced Rotamerization in an Argon Matrix

A cis/trans equilibrium mixture of matrix-isolated oxalyl fluoride was irradiated with a narrowband tunable IR source in the 2nu (CO) spectral region (3680-3710 cm(-1)). Rotamerization of cis into trans and vice versa was achieved (even site selective) by selective IR pumping. The experiments strongly aided a detailed IR analysis of both rotamers. For a complete vibrational analysis, low-temperature Raman measurements were also performed. With the exception of the torsional vibration of cis oxalyl fluoride, all the fundamentals of both rotamers have been observed. Copyright 2000 Academic Press.

The use of low-resolution FT-IR spectrometry for the analysis of alcohols in breath

Fast and reliable diagnostic methods are needed for detection or exclusion of industrial solvents as a cause of intoxication. Analyzing human breath reveals the presence of any volatile substance. A portable Fourier transform infrared (FT-IR) multicomponent point-of-care analyzer was developed for exhaled breath. The analyzer proved to be accurate and precise in laboratory tests for simultaneous measurement of methanol and ethanol in water. Ethanol, in addition to normal contents of breath, was simultaneously analyzed in human experiments, and the results correlated well with blood samples. FT-IR method has a traceable calibration to physical properties of the analyte. The measured spectra can also be saved and analyzed later. Breath analysis with FT-IR is fast and easy, and no preparation of the sample is needed.

Familial association between allergic disorders and depression in adult Finnish twins

Clinical studies have shown a relationship between allergic disorders and depression, panic disorder, attention deficit/hyperactivity disorder, and social anxiety for a significant subset of patients with these disorders. The nature of the relationship, whether due to shared environmental or biologic vulnerabilities or as a result of the stress of chronic illness, has been less clear. By examining the covariance of atopic disorders and depressive symptoms in a community sample of monozygotic (MZ) and dizygotic (DZ) twins, the contribution of genetic and/or shared environmental etiological factors can be established. A Finnish sample of 1337 MZ and 2506 DZ twin pairs, ages 33-60 years, was sent questionnaires inquiring about history of asthma, eczema, and atopic rhinitis, as well as the Beck Depression Inventory (BDI). The nature of the covariation between twins of these symptoms was investigated by fitting competing genetic and environmental models. Within-person correlation between atopic symptoms and BDI was 0.103 (P < 0.001) for the total sample. Using the Mx statistical modeling program to fit the data to competing quantitative genetic models, the best fitting model estimated that 64% of the association between atopy and BDI was due to shared familial vulnerability, primarily additive genetic influences. Although the measures for allergic disorders and depression are crude, this study supports the hypothesis that there is a small shared genetic risk for atopic and depressive symptoms, and if replicated, may open research for common mechanisms between allergic and depressive disorders. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:146-153, 2000.

Perinatal risk factors for asthma in Finnish adolescent twins

BACKGROUND

Previous studies have suggested that, in addition to genetic liability and environment in early childhood, intrauterine life also influences the risk for asthma beyond childhood. Low birth weight, prematurity, young maternal age, and maternal smoking have all shown an association with asthma. The effect of perinatal factors on the risk for asthma in relation to familial and social risk factors was studied in a nationwide population-based sample of adolescent twins. In addition to a distribution of birth characteristics among twins which differs from that of singletons, data on twins enable a distinction to be made between genetic and environmental sources of variation.

METHODS

Questionnaires were sent to five consecutive birth cohorts of Finnish 16 year old twins born in 1975-9 and to their parents (3065 families). The outcome measure was life time prevalence of doctor-diagnosed asthma in these adolescents. The association between asthma and potential risk factors was assessed by multiple logistic regression and discordant twin pair analysis.

RESULTS

Risk for asthma increased with increasing ponderal index (p for trend <0.01) and decreasing maternal age (p for trend <0.05). Among the 25% of twins with the highest ponderal index, the odds ratio for asthma was 1.82 (95% confidence interval 1.18 to 2.79) compared with those in the lowest 25%. Neither birth weight, gestational age, nor Apgar score was associated with asthma. When perinatal risk factors were combined with familial and social risk factors, ponderal index, maternal smoking, parental asthma, and sibship size were all significant independent determinants of asthma in these adolescents.

CONCLUSIONS

The risk for asthma in adolescent twins increases with increasing ponderal index when adjusted for familial and social factors.

Hay fever--a Finnish nationwide study of adolescent twins and their parents

BACKGROUND

Like other atopic diseases, hay fever is known to cluster in families. This clustering is due either to effects of a shared family environment or to genetic inheritance. By comparing the occurrence of hay fever among monozygous (MZ) and dizygous (DZ) twin pairs, we were able to estimate the contribution of genetic and environmental factors in the development of hay fever.

METHODS

A questionnaire mailed to a nationwide sample of 2483 families with 16-year-old twins furnished data for the cumulative incidence of physician-diagnosed hay fever among these adolescents and their parents.

RESULTS

Among the 1765 twin pairs with data available for analysis, hay fever was reported for 14.1% of boys (95% CI=12.4-15.8%) and 10.0% of girls (95% CI=8.6-11.4%). The MZ twin pairs (probandwise concordance rate=60.3%, 95% CI =52-68%) were significantly more concordant for hay fever than were DZ twin pairs (31.5%, 95% CI=26-36%). Genetic factors accounted for 74-82% of the interindividual variability in liability to hay fever, variation in shared family environment for 7% at most, and unique (individual) environment for 18%.

CONCLUSIONS

Familial occurrence of hay fever is mainly due to genes predisposing to the trait. Environmental exposures shared in common by family members but varying between families appear to account for at most a modest proportion of the variability in risk of developing hay fever.

Attention and expectation problems in bicycle-car collisions: an in-depth study

One hundred and eighty-eight bicycle-car accidents in four cities were studied by multidisciplinary in-depth analysis. The sample was representative of the national accident statistics. All the accidents were analyzed in detail to reconstruct the actual movements of those involved and to assess detection of the other party. In 37% of collisions, neither driver nor cyclist realized the danger or had time to yield. In the remaining collisions, the driver (27%), the cyclist (24%) or both (12%) did something to avert the accident. Two common mechanisms underlying the accidents were identified. First, allocation of attention such that others were not detected, and second, unjustified expectations about the behavior of others. These mechanisms were found to be closely related to the system of two-way cycle tracks and to the fact that the general priority rule is applied to the crossings of a cycle track and a roadway. The most frequent accident type among collisions between cyclists and cars at bicycle crossings was a driver turning right and a bicycle coming from the driver's right along a cycle track. The result confirmed an earlier finding (Accident Analysis and Prevention 28, 147-153, 1996) that drivers turning right hit cyclists because they looked left for cars during the critical phase. Only 11% of drivers noticed the cyclist before impact. Cyclists' behavior was in marked contrast to that of drivers. In these cases, 68% of cyclists noticed the driver before the accident, and 92% of those who noticed believed the driver would give way as required by law. Cyclists with a driving license and those who cycled daily through the accident site were involved in different accident types to other cyclists.

Importance of genetic factors in adolescent asthma: a population-based twin-family study

Gene-environment interactions and inheritance of asthma were studied in 16-yr-old twins and their parents who participated in the nationwide Finnish Twin Cohort Study. Between 1991 and 1994, questionnaires, including a question on physician-diagnosed asthma, were mailed to the members of 2,483 twin families. The individual response rate ranged from 82 to 93%. Information on parental asthma status allowed the genetic modeling of asthma data in two different groups of twins. In families where one of the parents was asthmatic, as much as 87% of the variation in susceptibility to asthma in twins was explained by genetic factors. On the other hand, for twins whose parents were unaffected, a model including environmental effect alone was sufficient to explain the development of asthma. Genetic influences could not be totally excluded, but their role was significantly smaller. These results indicate that the presence of asthma in successive generations is more likely caused by shared genes than shared environmental risk factors; however, substantial heterogeneity among families may exist. Genetic analysis, especially among the families with an obvious familial component in development of asthma, may enhance the chances of revealing the pathogenetic mechanisms

Hay fever, asthma and number of older siblings--a twin study

BACKGROUND

It has been suggested that allergic sensitization is inversely related to the number of siblings in the family.

OBJECTIVES

To study whether a similar relation can be observed for hay fever and asthma among Finnish adolescents in a population with relatively low prevalence of atopic diseases.

METHODS

A questionnaire mailed to a nationwide sample of 1849 families with 16-year-old twins assessing the cumulative incidence of doctor-diagnosed hay fever and asthma among the adolescents and the number of older siblings in the family by parental report.

RESULTS

The cumulative incidence of hay fever was significantly lower among the adolescents with three or more older siblings (3.9%, 95% CI = 1.2-6.5%) compared with adolescents with fewer older siblings (12.7%, 95% CI = 11.4-14.0%). There was no difference in the cumulative incidence of asthma among the adolescents according to the number of older siblings in the family.

CONCLUSIONS

Large number of older siblings appears to be protective against the development of hay fever.

Bicycle accidents and drivers' visual search at left and right turns

The accident data base of the City of Helsinki shows that when drivers cross a cycle path as they enter a non-signalized intersection, the clearly dominant type of car-cycle crashes is that in which a cyclist comes from the right and the driver is turning right, in marked contrast to the cases with drivers turning left (Pasanen 1992; City of Helsinki, Traffic Planning Department, Report L4). This study first tested an explanation that drivers turning right simply focus their attention on the cars coming from the left-those coming from the right posing no threat to them-and fail to see the cyclist from the right early enough. Drivers' scanning behavior was studied at two T-intersections. Two well-hidden video cameras were used, one to measure the head movements of the approaching drivers and the other one to measure speed and distance from the cycle crossroad. The results supported the hypothesis: the drivers turning right scanned the right leg of the T-intersection less frequently and later than those turning left. Thus, it appears that drivers develop a visual scanning strategy which concentrates on detection of more frequent and major dangers but ignores and may even mask visual information on less frequent dangers. The second part of the study evaluated different countermeasures, including speed humps, in terms of drivers' visual search behavior. The results suggested that speed-reducing countermeasures changed drivers' visual search patterns in favor of the cyclists coming from the right, presumably at least in part due to the fact that drivers were simply provided with more time to focus on each direction.

Seminal fluid antisperm antibodies measured by direct flow cytometry do not correlate with those measured by indirect flow cytometry, the indirect immunobead test, and the indirect mixed antiglobulin reaction

OBJECTIVE

To compare the direct flow cytometric (FCM) measurement of sperm-bound antibodies with the indirect FCM measurement of unbound antisperm antibodies in seminal plasma of the same ejaculates. To compare the FCM measurements with the indirect mixed antiglobulin reaction (MAR) and the indirect immunobead test (IBT) performed on the same seminal plasmas.

SETTING

University hospital-based infertility service.

PATIENTS

Eleven infertile men with a positive immunoglobulin (Ig) G direct MAR test and antibody positivity on the direct FCM measurements. Four control patients with a negative IgG-direct MAR test.

MAIN OUTCOME MEASURES

The proportion of spermatozoa positive for IgG and IgA antibodies as measured by various tests.

RESULTS

The direct and indirect FCM measurements for sperm-bound antibodies from seminal plasma did not correlate with each other. In general, IgG antibodies were not detectable by indirect FCM whereas IgA were detected in lower proportions than by direct FCM measurements. Weak correlation was observed between the indirect FCM, indirect MAR, and indirect IBT measurements.

CONCLUSION

Nearly all of the IgG and some of the IgA antisperm antibodies in seminal fluid bind to spermatozoa. Thus, indirect tests to measure antisperm antibodies from seminal plasma are likely to miss the presence of antisperm IgG antibodies while detecting some cases of IgA antibodies.

Low-dose prednisolone does not improve the outcome of in-vitro fertilization in male immunological infertility

Early reports of male immunological infertility suggested a decline in antisperm antibody concentrations in some patients after even short-term (10 day) therapy with low-dose prednisolone. In the present study, 53 men with positive results in spermatozoal mixed antiglobulin reaction (MAR) and serum tray agglutination tests (TAT), were randomized to receive either 20 mg of prednisolone or placebo daily for 2 weeks prior to in-vitro fertilization (IVF) treatment. The antibody levels were also monitored by flow cytometry (FCM). There were no significant differences between these groups as regards fertilization rates (35% with prednisolone; 39% with placebo) and pregnancy rates (29%; 32%). No significant changes occurred in either MAR or FCM results in relation to therapy. Patients with fertilization rates of < 10% had significantly higher immunoglobulin G (IgG) MAR values compared with those with better fertilization, whereas there was no relationship between IgA levels and fertilization results. As regards FCM, the results were similar, but without statistical significance. In conclusion, IVF is a good course of action in severe male immune infertility, but low-dose prednisolone therapy does not lower the sperm-bound antibody numbers and does not improve the IVF outcome.

A flow cytometric study on the effect of low dose cyclic prednisolone treatment on sperm-bound antibody levels

Using flow cytometry the changes in the proportion of spermatozoa positive for antisperm antibody, and for levels of sperm-bound immunoglobulin (Ig)G and IgA antibody and some other semen parameters were monitored during low dose cyclic prednisolone treatment to 11 male patients. Patients were given prednisolone 20 mg/day for the first 10 days of the partner's menstrual cycle and then 5 mg on days 11 and 12. The treatment was repeated for three cycles and the sperm parameters measured after the first cycle, third cycle and in four cases also 1 and 3 months after cessation of treatment. A clear reduction of sperm-bound IgG antibody levels was seen in 3/11 (27%) patients, while only IgA was reduced in 2/11 (18%) patients. Only minor changes in sperm-bound antibody levels were shown in 63% (7/11) of patients, and in one patient the levels of sperm antibody even increased. Thus, corticosteroid treatment did not reduce sperm-bound antibodies in the majority of cases. In those cases in which the levels of sperm antibody declined, the decrease in sperm-bound antibodies was noticeable even after one cycle of prednisolone treatment.

Comparison of flow cytometric measurement of seminal antisperm antibodies with the mixed antiglobulin reaction and the serum tray agglutination test

OBJECTIVE

To compare the mixed antiglobulin reaction (MAR) and the serum tray agglutination test (TAT) with the flow cytometric (FCM) measurement of sperm antibodies. To evaluate by FCM the correlation in sperm antibody parameters between paired semen ejaculates obtained 2 to 4 weeks apart and the effect of washing on sperm antibody levels.

SETTING

University-based infertility clinic.

PATIENTS

The TAT and FCM were done on 81 patients with a positive immunoglobulin (Ig)G-MAR test. The correlation of sperm antibody parameters between paired semen samples was done in 16 men. A few samples were used to study the effect of washing on sperm antibody parameters.

MAIN OUTCOME MEASURES

The proportion of spermatozoa positive for IgG and IgA antibodies as well as the number of antibody molecules per spermatozoa measured by FCM.

RESULTS

In general, the degree of MAR positivity but not that of the TAT correlated with the sperm antibody load. With reference to FCM the MAR test had an 1% false positive rate, whereas the serum TAT had a 25% false negative rate. Correlation between FCM measurements of paired semen samples was good. Washing the spermatozoa once removed the loosely bound antibodies; further washes were not useful.

CONCLUSION

Flow cytometry is a reliable technique that correlates with the MAR test. In patients with a strongly positive MAR, FCM is useful to identify patients with a low sperm antibody load. It is speculated that patients with a low sperm antibody load may respond better to IVF treatment.

Studies on phospholipase A2 in human seminal plasma

1. Human seminal plasma and posterior lobe of prostate was found to have phospholipase A2 (PLA2) activity hydrolysing phosphatidylethanolamine with 14C-labelled linoleic and arachidonic acid. 2. A negative relationship was between sperm count and PLA2 activity in human seminal plasma. 3. The purified PLA2 from human seminal plasma showed high affinity to heparin, sensitivity toward p-bromophenacyl bromide, Pb2+, dithioerythritol and EDTA and it was activated by Ca2+ and Mn2+. 4. The purified PLA2 had alkaline pH optimum (7.5-10.0) and pI-value of 5.3. In SDS-PAGE enzyme preparation resulted in two bands with mol. wt of 14,000 and 16,000.