Rapid Homogeneous Immunoassay Based on Time-Resolved F?rster Resonance Energy Transfer for Serodiagnosis of Acute Hantavirus Infection

We recently introduced a homogeneous immunoassay based on time-resolved Förster resonance energy transfer (TR-FRET) elicited by fluorophore-labeled antigen and fluorophore-labeled protein L, bound by an immunoglobulin. As the first clinical application, we employ this approach (LFRET) in serodiagnosis of Puumala hantavirus (PUUV) infection. A reference panel containing serum from individuals with acute (n = 21) or past (n = 17) PUUV infection and from PUUV-seronegative individuals (n = 20) was used to define the parameters. The clinical assay performance was evaluated with a prospectively collected serum panel (panel 2; n = 153). Based on the results for panel 1, the threshold for positivity was set at a signal level that was 3-fold over background, while those with a signal <3-fold over the background level were considered PUUV seronegative. With panel 1, 20/21 acute- and 7/10 past-infection samples induced positive signals, compared to 0/20 seronegatives. With panel 2, a positive signal was obtained in 39/40 acute- and 4/10 past-infection samples, as opposed to 7/103 seronegatives. However, after IgG depletion, 58/61 acute-infection samples were LFRET positive, while all past-infection and seronegative samples were negative, corresponding to 100% specificity and 95% sensitivity in detection of acute PUUV infection. We demonstrate that the novel immunoassay is a promising tool for rapid serodiagnosis of acute Puumala virus infection.     

Association of human bocavirus 1 infection with respiratory disease in childhood follow-up study, Finland

Human bocavirus 1 (HBoV1) DNA is frequently detected in the upper airways of young children with respiratory symptoms. Because of its persistence and frequent co-detection with other viruses, however, its etiologic role has remained controversial. During 2009-2011, using HBoV1 IgM, IgG, and IgG-avidity enzyme immunoassays and quantitative PCR, we examined 1,952 serum samples collected consecutively at 3- to 6-month intervals from 109 constitutionally healthy children from infancy to early adolescence. Primary HBoV1 infection, as indicated by seroconversion, appeared in 102 (94%) of 109 children at a mean age of 2.3 years; the remaining 7 children were IgG antibody positive from birth. Subsequent secondary infections or IgG antibody increases were evident in 38 children and IgG reversions in 10. Comparison of the seroconversion interval with the next sampling interval for clinical events indicated that HBoV1 primary infection, but not secondary immune response, was significantly associated with acute otitis media and respiratory illness.     

Oral health-related knowledge,attitudes and habits in relation to perceived oral symptoms among 12-year-old school children

Objective The aim of the study was to investigate oral health-related knowledge, attitudes and habits and their relationship to perceived oral symptoms among 12-year-olds and differences between boys and girls. Material and methods The study population consisted of children (n?=?588) in 15 randomly selected elementary schools in Turku, Finland. Associations between oral health-related habits, knowledge and attitudes with perceived oral symptoms and gender differences were evaluated with χ²-test, Mann-Whitney U-test and logistic regression analysis. Results Oral health promoting habits but not knowledge or attitudes associated significantly with absence of oral symptoms. Girls reported a higher percentage of several health promotional habits than boys. Girls reported more frequently gingival bleeding and less frequently dental calculus than boys did. The most common oral symptom was gingival bleeding. Conclusions The present findings suggest some gender-related differences in oral health habits, attitudes, as well as perceived oral symptoms in 12-year-olds. There seems, however, not to be gender differences in relation to knowledge or the association of health habits with perceived oral symptoms. It is important to maintain health promotion at schools and additional efforts should be aimed at translating knowledge into action.     

A novel mutation, Ser143Pro, in the lamin A/C gene is common in finnish patients with familial dilated cardiomyopathy.

AIMS: The mutations most frequently associated with dilated cardiomyopathy (DCM) have been reported in the lamin A/C gene. The role of variants of the lamin A/C gene was investigated in patients with DCM from eastern and southern Finland. METHODS AND RESULTS: All 12 exons of the lamin A/C gene were screened in 18 well-characterised familial DCM patients from eastern and southern Finland and in 72 sporadic DCM patients from eastern Finland using the PCR-SSCP method. A novel mutation, Ser143Pro (S143P), was detected in the lamin A/C gene in 24 subjects from 5 unrelated families and in one sporadic case of DCM. Sinus or atrioventricular nodal dysfunction occurred in the majority of the affected subjects, many of which required pacemaker implantation. Seven patients (28%) with the S143P mutation died suddenly or from progressive heart failure, or underwent heart transplantation. The haplotypes 5-5-5-3, 5-5-5-2, and 5-5-5-1 co-segregated with the Ser143Pro mutation, suggesting a founder effect of this mutation. CONCLUSIONS: A novel mutation S143P in the lamin A/C gene was found to be common among Finnish DCM patients. Haplotype analysis strongly suggests a founder effect of this mutation. The phenotype is characterised by severe heart failure, progressive atrioventricular conduction defects, and sudden death. Screening for the lamin A/C gene and, particularly, the S143P mutation seems warranted when patients with DCM have conduction system disturbances.     

Plantar shear stress measurements — A review

Background

Mechanical stress at the plantar surface has two components, pressure acting normal to the surface and shear stress acting tangential to the surface. Typically only pressure is measured and reported. However, plantar shear stress also plays a major role, especially in diabetic ulceration.

Methods

During the last few decades, a variety of methods have been developed for the measurement of plantar shear stress. This paper reviews the technologies used in plantar shear stress measurements.

Findings

Several technologies have been used, e.g. magneto-resistors, strain gauges, optical methods, piezoelectric materials and capacitive sensors. Examples of plantar shear stress values measured with the developed devices are also collected here and the relationship between sensor characteristics and the measured plantar shear stress distribution is discussed.

Interpretation

Even with the limitations of current plantar shear stress measurement technologies, they can provide useful information on the plantar stress distribution.     

Ontogeny of pineal melatonin rhythm in rats under 12: 12-hr and 14: 14-hr lightdark conditions

Abstract: The aim of the study was to determine whether a discrepancy between the genetically determined endogenous circadian period and an abnormally long Zeitgeber period disturbs the development of melatonin synthesis. Breeding pairs of rats were kept under 12: 12- or 14: 14-hr light: dark (LD) conditions. Pineal melatonin contents in the offspring were measured by radioimmunoassay. At 2 weeks of age high melatonin contents were found from lights-off to lights-on in both conditions suggesting dominance of the photic regulation. At 3 weeks of age the signs of the circadian regulation in the melatonin profiles were evident: a lag period after the light offset in control conditions and a significant decline before the light onset in both conditions. However, in 14: 14-hr LD conditions the melatonin content did not decrease to daytime levels until the lights were on. This could suggest incomplete maturation of the circadian system. The phase relationships between the melatonin peak and LD cycle were different in the two conditions. A statistically significant LD difference was first found at the age of 8–10 days in male pups and at 14 days in female pups under both lightings. The results suggest that the abnormally long LD cycle did not cause any major disorders in the development of photic or circadian regulation of the melatonin synthesis.     

Studies on the Role of Lipid Peroxidation in the Acute Toxicity of TCDD in Rats*

Lipid peroxidation has been shown to be enhanced following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but its role in TCDD toxicity is unclear. The present study was undertaken to further elucidate the relations between lipid peroxidation and TCDD lethality. A time course and dose-response experiment in Long-Evans (L-E; LD50 ca. 10 μg/kg) and Han/Wistar (H/W; LD50 > 3000 μg/kg) rats showed that hepatic lipid peroxidation, measured as the amount of thiobarbituric acid-reactive substances (TBA-RS), was induced by TCDD dose-dependently in L-E, but not in H/W rats. Hepatic glutathione peroxidase activity was suppressed in much the same manner in both strains. Lipid peroxidation correlated with body weight loss in L-E rats alone. When 500 μg/kg of TCDD was given to L-E rats, lipid peroxidation increased about 3-fold on Day 11 in the liver, while no change was seen in cardiac or renal TBA-RS. The pair-fed controls did not survive the 11-day test period and exhibited gastrointestinal hemorrhages. At 6 days, liver atrophy and elevated (over 2-fold) TBA-RS values were recorded in pair-fed controls but not in their TCDD-treated counterparts. TCDD decreased hepatic glutathione peroxidase activity by almost 50% at 6 days, while pair-feeding was without effect. Liver morphology was different between TCDD-treated and pair-fed rats. Moreover, the livers of TCDD-treated L-E rats contained much higher concentrations of probably peripheral fat-derived fatty acids than did the livers of pair-fed or ad libitum control rats. Restricted feeding over 6 days induced hepatic lipid peroxidation more in H/W than in L-E rats. Endotoxin increased liver TBA levels similarly in both strains having an additive effect with high doses of TCDD in H/W rats. Added as a 0.5% concentration in chow, butylated hydroxyanisole (BHA), but not ethoxyquin, tended to increase survival rate and time in L-E rats exposed to 20 μg/kg of TCDD; at 50 μg/kg the only survivor was again in the BHA group. However, neither antioxidant had any effect on initial body weight loss. It is concluded that lipid peroxidation mainly arises as a secondary phenomenon in TCDD toxicity, is not the cause of the typical histopathological liver lesion, but may contribute to lethality.